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Sample records for chain wheel shape

  1. A Shape-Persistent Polyphenylene Spoked Wheel.

    PubMed

    Liu, Yi; Narita, Akimitsu; Teyssandier, Joan; Wagner, Manfred; De Feyter, Steven; Feng, Xinliang; Müllen, Klaus

    2016-12-07

    A shape-persistent polyphenylene with a "spoked wheel" structure was synthesized as a subunit of an unprecedented two-dimensional polyphenylene that we name graphenylene. The synthesis was carried out through a sixfold intramolecular Yamamoto coupling of a dodecabromo-substituted dendritic polyphenylene precursor, which had a central hexaphenylbenzene unit as a template. Characterizations by NMR spectroscopy and matrix-assisted laser ionization time-of-flight mass spectrometry provided an unambiguous structural proof for the wheel-like molecule with a molar mass of 3815.4 g/mol. Remarkably, scanning tunneling microscopy visualization clearly revealed the defined spoked wheel structure of the molecule with six internal pores.

  2. In-process electrical discharge dressing of arc-shaped metal bonded diamond wheels

    NASA Astrophysics Data System (ADS)

    Wang, Kai; Fan, Fei; Tian, Guoyu; Zhang, Feihu; Liu, Zhongde

    2016-10-01

    Due to the high hardness of SiC ceramics, the wear of the arc-shaped metal bonded diamond wheels is very serious during the grinding process of large-aperture aspheric SiC mirrors. The surface accuracy and surface/sub-surface quality of the aspheric mirror will be affected seriously if the grinding wheel is not timely dressed. Therefore, this paper focus on the in-process dressing of the arc-shaped metal bonded diamond wheels. In this paper, the application of the asymmetric arc profile grinding wheel in the grinding of aspheric mirrors is discussed first. Then a rotating cup-shaped electrode in-process electro discharge dressing device for the arc-shaped wheels is developed based on the analysis. The dressing experiments are carried out with the device. The experimental results show that the in-process dressing device can did the dressing for the asymmetric and symmetric arc-shaped wheel. The profile error of the arc can reach to 3μm with the in-process dressing device.

  3. Wheel-shaped [Mn12] single-molecule magnets.

    PubMed

    Rumberger, Evan M; Shah, Sonali J; Beedle, Christopher C; Zakharov, Lev N; Rheingold, Arnold L; Hendrickson, David N

    2005-04-18

    The reaction of [Mn(12)O(12)(O(2)CCH(3))(16)(H(2)O)(4)].4H(2)O.2CH(3)COOH with n-methyldiethanol amine (H(2)mdea), n-ethyldiethanol amine (H(2)edea), or n-butyldiethanol amine (H(2)bdea) leads to the formation of wheel-shaped Mn(III)(6)Mn(II)(6) complexes with the general formula [Mn(12)(R)(O(2)CCH(3))(14)] (1, R = mdea; 2, R = edea; and 3, R = bdea). Complex 1 crystallizes in the triclinic space group P1, whereas complex 3 crystallizes in the monoclinic space group C(2/c). Complex 1a has the same molecular structure as complex 1 but crystallizes in the monoclinic space group P2(1/n). Complex 3a has the same molecular structure as complex 3 but crystallizes in the triclinic space group P1. Variable-temperature magnetic susceptibility data collected for complexes 1, 2, and 3 indicate that antiferromagnetic exchange interactions are present. The spin ground states of complexes 1, 2, and 3 were determined by fitting variable-field magnetization data collected in the 2-5 K temperature range. Fitting of these data yielded the spin ground-state parameters of S = 8, g = 2.0, and D = -0.47 cm(-1) for complex 1; S = 8, g = 2.0, and D = -0.49 cm(-1) for complex 2; and S = 8, g = 2, and D = -0.37 cm(-1) for complex 3. The ac magnetic susceptibility data were measured for complexes 1, 2, and 3 at temperatures between 1.8 and 10 K with a 3 G ac field oscillating in the range 50-1000 Hz. Slow kinetics of magnetization reversal relative to the frequency of the oscillating ac field were observed as frequency-dependent out-of-phase peaks for complexes 1, 2, and 3, and it can be concluded that these three complexes are single-molecule magnets.

  4. The chloridomolybdenum(III) cluster in [BMIm]4[AgMo10Cl35] with infinite chains of Ag(+)-linked [Mo10Cl35](5-) wheels.

    PubMed

    Freudenmann, Dominic; Feldmann, Claus

    2014-10-07

    [BMIm]4[AgMo10Cl35] is prepared by reaction of MoCl5 and elemental silver in the ionic liquid [BMIm][AlCl4] ([BMIm(+)]: 1-butyl-4-methylimidazolium). Surprisingly, elemental silver is oxidized under these conditions. The title compound contains a new wheel-shaped [Mo10Cl35](5-) chlorido molybdenum(iii) species with five pairs of Mo-Mo bonds. The Mo-Mo distances are found to be 263 pm on average. The [Mo10Cl35](5-) wheels exhibit a maximum opening of 558 pm in diameter. They are interlinked via Ag(+) to form infinite [AgMo10Cl35](4-) chains. The title compound is characterized by single crystal structure analysis, EDX, FT-IR and UV-Vis spectroscopy. The wheel-type structure and Ag(+) linkage to infinite chains are a new aspect of halogenido metalates and low-valence molybdenum compounds.

  5. Self-assembly in aqueous solution of wheel-shaped Mo154 oxide clusters into vesicles.

    PubMed

    Liu, Tianbo; Diemann, Ekkehard; Li, Huilin; Dress, Andreas W M; Müller, Achim

    2003-11-06

    Surfactants and membrane lipids readily assemble into complex structures such as micelles, liposomes or hollow vesicles owing to their amphiphilic character-the fact that part of their structure is attracted to polar environments while another part is attracted to non-polar environments. The self-assembly of complex structures also occurs in polyoxometallate chemistry, as exemplified by the molybdenum blue solutions known for centuries. But while the presence of nanometre-sized metal oxide aggregates in these solutions has long been recognized, unravelling the composition and formation process of these aggregates proved difficult. Recent work has indicated that discrete, wheel-shaped mixed-valence polyoxomolybdate clusters of the type [Mo154] (refs 2-4) assemble into well-defined nanometre-sized aggregates, including spherical structures. Here we report light-scattering data and transmission electron microscopy images of hollow spherical structures with an average, almost monodisperse radius of about 45 nm and composed of approximately 1,165 [Mo154] wheel-shaped clusters. The clusters appear to lie flat and homogeneously distributed on the vesicle surface. Unlike conventional lipid vesicles, the structures we observe are not stabilized by hydrophobic interactions. Instead, we believe the polyoxomolybdate-based vesicles form owing to a subtle interplay between short-range van der Waals attraction and long-range electrostatic repulsion, with important further stabilization arising from hydrogen bonding involving water molecules encapsulated between the wheel-shaped clusters and in the vesicles' interior.

  6. Simulation and Fabrication of Wagon-Wheel-Shaped Piezoelectric Transducer for Raindrop Energy Harvesting Application

    NASA Astrophysics Data System (ADS)

    Wong, Chin Hong; Dahari, Zuraini; Jumali, Mohammad Hafizuddin; Mohamed, Khairudin; Mohamed, Julie Juliewatty

    2017-01-01

    Harvesting vibrational energy from impacting raindrops using piezoelectric material has been proven to be a promising approach for future outdoor applications, providing a good alternative resource that can be applied in outdoor rainy environments. We present herein an optimum novel polyvinylidene fluoride (PVDF) piezoelectric transducer specifically developed to harvest raindrop energy. The finite-element method was applied for simulation and optimization of the piezoelectric raindrop energy harvester (PREH) using COMSOL Multiphysics software, investigating the electrical potential, surface charge density, and total displacement for different transducer dimensions. According to the simulation results, the structure that generated the highest electrical potential and surface charge density was a wagon-wheel-shaped structure consisting of six spokes with wheel diameter of 30 mm, spoke width of 2 mm, center pad diameter of 6 mm, and thickness of 25 μm. This optimum wagon-wheel-shaped device was then fabricated by spin coating of PVDF, sputtering of aluminum, a poling process, and computer numerical control machining of a polytetrafluoroethylene stand. The fabricated PREH was characterized by x-ray diffraction analysis and Fourier-transform infrared spectroscopy. Finally, the fabricated PREH was tested under actual rain conditions with an alternating current to direct current converter connected in parallel, revealing that a single cell could generate average peak voltage of 22.5 mV and produce electrical energy of 3.4 nJ from ten impacts in 20 s.

  7. Simulation and Fabrication of Wagon-Wheel-Shaped Piezoelectric Transducer for Raindrop Energy Harvesting Application

    NASA Astrophysics Data System (ADS)

    Wong, Chin Hong; Dahari, Zuraini; Jumali, Mohammad Hafizuddin; Mohamed, Khairudin; Mohamed, Julie Juliewatty

    2017-03-01

    Harvesting vibrational energy from impacting raindrops using piezoelectric material has been proven to be a promising approach for future outdoor applications, providing a good alternative resource that can be applied in outdoor rainy environments. We present herein an optimum novel polyvinylidene fluoride (PVDF) piezoelectric transducer specifically developed to harvest raindrop energy. The finite-element method was applied for simulation and optimization of the piezoelectric raindrop energy harvester (PREH) using COMSOL Multiphysics software, investigating the electrical potential, surface charge density, and total displacement for different transducer dimensions. According to the simulation results, the structure that generated the highest electrical potential and surface charge density was a wagon-wheel-shaped structure consisting of six spokes with wheel diameter of 30 mm, spoke width of 2 mm, center pad diameter of 6 mm, and thickness of 25 μm. This optimum wagon-wheel-shaped device was then fabricated by spin coating of PVDF, sputtering of aluminum, a poling process, and computer numerical control machining of a polytetrafluoroethylene stand. The fabricated PREH was characterized by x-ray diffraction analysis and Fourier-transform infrared spectroscopy. Finally, the fabricated PREH was tested under actual rain conditions with an alternating current to direct current converter connected in parallel, revealing that a single cell could generate average peak voltage of 22.5 mV and produce electrical energy of 3.4 nJ from ten impacts in 20 s.

  8. Net-Shape Forming and Mechanical Properties of MIM418 Turbine Wheel

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Chen, Xiaowei; Li, Dan; Xuanhui, Qu; Mingli, Qin; Li, Zhou

    2016-09-01

    Near-net shape forming of the turbine wheel with a hollow internal structure was realized by adopting the die with side core-pulling mechanism. MIM418 turbine wheel with relative density above 99.5% is obtained by the combination of vacuum sintering and hot isostatic pressing. A high volume fraction (57%) of near cuboidal γ' phase with average particle size of 0.52 μm is formed in γ matrix. Small amount of discrete carbides with size of 0.2-0.4 μm is distributed uniformly on grain boundaries and within grains. The tensile strength, yield strength, and ductility of MIM418 superalloy reach 1425 MPa, 1004 MPa, and 19.4%, respectively, which are much higher than that of the cast K418 superalloy.

  9. Computer numerically controlled (CNC) aspheric shaping with toroidal Wheels (Abstract Only)

    NASA Astrophysics Data System (ADS)

    Ketelsen, D.; Kittrell, W. C.; Kuhn, W. M.; Parks, R. E.; Lamb, George L.; Baker, Lynn

    1987-01-01

    Contouring with computer numerically controlled (CNC) machines can be accomplished with several different tool geometries and coordinated machine axes. To minimize the number of coordinated axes for nonsymmetric work to three, it is common practice to use a spherically shaped tool such as a ball-end mill. However, to minimize grooving due to the feed and ball radius, it is desirable to use a long ball radius, but there is clearly a practical limit to ball diameter with the spherical tool. We have found that the use of commercially available toroidal wheels permits long effective cutting radii, which in turn improve finish and minimize grooving for a set feed. In addition, toroidal wheels are easier than spherical wheels to center accurately. Cutting parameters are also easier to control because the feed rate past the tool does not change as the slope of the work changes. The drawback to the toroidal wheel is the more complex calculation of the tool path. Of course, once the algorithm is worked out, the tool path is as easily calculated as for a spherical tool. We have performed two experiments with the Large Optical Generator (LOG) that were ideally suited to three-axis contouring--surfaces that have no axis of rotational symmetry. By oscillating the cutting head horizontally or vertically (in addition to the motions required to generate the power of the surface) , and carefully coordinating those motions with table rotation, the mostly astigmatic departure for these surfaces is produced. The first experiment was a pair of reflector molds that together correct the spherical aberration of the Arecibo radio telescope. The larger of these was 5 m in diameter and had a 12 cm departure from the best-fit sphere. The second experiment was the generation of a purely astigmatic surface to demonstrate the feasibility of producing axially symmetric asphe.rics while mounted and rotated about any off-axis point. Measurements of the latter (the first experiment had relatively

  10. A case study in experiential learning: pharmaceutical cold chain management on wheels.

    PubMed

    Vesper, James; Kartoglu, Ümit; Bishara, Rafik; Reeves, Thomas

    2010-01-01

    People who handle and regulate temperature-sensitive pharmaceutical products require the knowledge and skills to ensure those products maintain quality, integrity, safety, and efficacy throughout their shelf life. People best acquire such knowledge and skills through "experiential learning" that involves working with other learners and experts. The World Health Organization developed a weeklong experiential learning event for participants so they could gain experience in how temperature-sensitive products are handled, stored, and distributed throughout the length of the distribution supply chain system. This experiential learning method enabled participants to visit, critically observe, discuss and report on the various components of the cold chain process. An emphasis was placed on team members working together to learn from one another and on several global expert mentors who were available to guide the learning, share their experiences, and respond to questions. The learning event, Pharmaceutical Cold Chain Management on Wheels, has been conducted once each year since 2008 in Turkey with participants from the global pharmaceutical industry, health care providers, national regulatory authorities, and suppliers/vendors. Observations made during the course showed that it was consistent with the principles of experiential and social learning theories. Questionnaires and focus groups provided evidence of the value of the learning event and ways to improve it. Reflecting the critical elements derived from experiential and social learning theories, five factors contributed to the success of this unique experiential learning event. These factors may also have relevance in other experiential learning courses and, potentially, for experiential e-learning events.

  11. Influence of wheel and rail profile shape on the initiation of rolling contact fatigue cracks at high axle loads

    NASA Astrophysics Data System (ADS)

    Spangenberg, Ulrich; Desmond Fröhling, Robert; Schalk Els, Pieter

    2016-05-01

    The influence of wheel and rail profile shape features on the initiation of rolling contact fatigue (RCF) cracks is evaluated based on the results of multi-body vehicle dynamics simulations. The damage index and surface fatigue index are used as two damage parameters to assess the influence of the different features. The damage parameters showed good agreement to one another and to in-field observations. The wheel and rail profile shape features showed a correlation to the predicted RCF damage. The RCF damage proved to be most sensitive to the position of hollow wear and thus bogie tracking. RCF initiation and crack growth can be reduced by eliminating unwanted shape features through maintenance and design and by improving bogie tracking.

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

    PubMed

    Basso, Julia C; Morrell, Joan I

    2017-10-01

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

  13. Synthesis, crystal structure and luminescence properties of "paddle wheel" and "butterfly" shaped polynuclear complexes

    NASA Astrophysics Data System (ADS)

    Bai, Fenghua; Ni, Yulan; Jiang, Yang; Feng, Xuenan; Wuren, Tuya; Zhang, Liping; Su, Haiquan

    2017-03-01

    A series of metal cluster-based complexes were constructed from the reaction of metal ions (FeIII, CuII, ZnII) and ligand (2-({2-[2-carbosybenzoy])oxy]-ethoxy}carbonyal)benzoic acid) (H2L) in CH3CH2OH, CH3OH, (C2H5)3N and C2H3N. Two paddle wheel trinuclear clusters [Fe3(μ3-O)(μ2-η2-L)3(CH3OH)3]NO3·C2H5OH·CH3OH (1) and [Fe3(μ3-O)(μ2-η2-L)3(H2O)3]NO3·5CH3OH·H2O (2), one tetranuclear cluster [Cu2(μ2-L)2(C2H3N)2·2C2H3N]2 (3) and one butterfly shaped dinuclear cluster [Zn2(μ2-L)2(C2H5OH)2]·2CH3OH (4) were obtained. Complexes 1, 2, and 4 are further assembled by intermolecular hydrogen bonds to form supramolecular frameworks. In complex 3, the flexible benzoic acid ligand chelates with two CuII, which induces a decrease of Cusbnd Cu intermetallic separation (rang from 2.644 to 2.657 Å). The structures of the complexes are characterized by elemental analyses, Infrared spectroscopy (IR spectroscopy), thermal gravimetry (TG) analyses, single crystal X-ray diffraction and powder X-ray diffraction techniques (PXRD), and high resolution mass spectra (HRMS). The luminescent properties of the clusters 1-4 are also studied, the results show that the cluster 4 exhibits blue fluorescence at room temperature.

  14. Development of a novel shape memory alloy-actuated resettable locking device for magnetic bearing reaction wheel.

    PubMed

    Zhang, Xiaoyong; Yan, Xiaojun; Zhang, Shaowei; Nie, Jingxu

    2014-01-01

    The current investigation proposes a shape memory alloy (SMA)-actuated resettable locking device for magnetic bearing reaction wheel. The device employed two SMA wire-based actuators to realize locking and unlocking. Dual-slope mating surfaces were used on one hand to transmit the motion between a moving part and a clamp, and on the other hand to achieve a self-locking linkage in the locking state. Moreover, geometric parameters of the two SMA wires and corresponding bias springs were also designed. Based on the proposed design scheme, four locking devices were manufactured and assembled. Performance and environmental tests were performed to verify the proposed locking device. Test results show that the locking device can protect the magnetic bearing reaction wheel from launch vibration damage, and can withstand the thermal environment in the launch and on-orbit stage. Moreover, the device can be successfully operated for 76 times, and the response time for the locking and unlocking processes under 7 V power supply is 0.9 s and 5.6 s, respectively. Considering the results obtained from these tests, we conclude that the proposed resettable locking device is an attractive alternative technology to conventional motor-driven or pyrotechnics-based technologies, and can be applied reliably in the magnetic bearing reaction wheel.

  15. Development of a novel shape memory alloy-actuated resettable locking device for magnetic bearing reaction wheel

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyong; Yan, Xiaojun; Zhang, Shaowei; Nie, Jingxu

    2014-01-01

    The current investigation proposes a shape memory alloy (SMA)-actuated resettable locking device for magnetic bearing reaction wheel. The device employed two SMA wire-based actuators to realize locking and unlocking. Dual-slope mating surfaces were used on one hand to transmit the motion between a moving part and a clamp, and on the other hand to achieve a self-locking linkage in the locking state. Moreover, geometric parameters of the two SMA wires and corresponding bias springs were also designed. Based on the proposed design scheme, four locking devices were manufactured and assembled. Performance and environmental tests were performed to verify the proposed locking device. Test results show that the locking device can protect the magnetic bearing reaction wheel from launch vibration damage, and can withstand the thermal environment in the launch and on-orbit stage. Moreover, the device can be successfully operated for 76 times, and the response time for the locking and unlocking processes under 7 V power supply is 0.9 s and 5.6 s, respectively. Considering the results obtained from these tests, we conclude that the proposed resettable locking device is an attractive alternative technology to conventional motor-driven or pyrotechnics-based technologies, and can be applied reliably in the magnetic bearing reaction wheel.

  16. Seizing market shaping opportunities for vaccine cold chain equipment.

    PubMed

    Azimi, Tara; Franzel, Lauren; Probst, Nina

    2017-04-19

    Gavi, the Vaccine Alliance, supports immunisation programmes in eligible countries to reach children with lifesaving vaccines. Dramatic improvement in the scale and performance of current cold chain systems is required to extend the reach of immunisation services - especially for children living in remote locations - to advance progress towards full vaccine coverage. Achieving these improvements will require a healthier market for cold chain equipment where the products meet user needs, are sustainably priced, and are available in sufficient quantities to meet demand. Yet evidence suggests that the cold chain market has suffered from several failures including limited demand visibility, fragmented procurement, and insufficient information exchange between manufacturers and buyers on needs and equipment performance. One of Gavi's strategic goals is to shape markets for vaccines and other immunisation products, including cold chain equipment and in 2015, Gavi created a new mechanism - the Cold Chain Equipment (CCE) Optimisation Platform - to strengthen country cold chain systems by offering financial support and incentives for higher performing CCE. The main objective of the CCE Platform is to get more equipment that is efficient, sustainable, and better performing deployed to every health facility where it is required at an affordable price. To achieve these objectives, Gavi is putting in place tested market shaping approaches and tools adapted for the CCE market: the development of market strategies or 'roadmaps'; improvement of product performance through the development of target product profiles (TPPs); strategic engagement with CCE manufacturers and countries to enhance information sharing; and tailoring procurement tactics to the CCE market. These approaches and tools will allow for increased demand and supply of higher-performing, cost-effective and quality products. By strengthening immunisation systems with improved cold chain equipment, Gavi countries can

  17. Ultrafine grinding using a fluidized bed opposed jet mill: effects of feed load and rotational speed of classifier wheel on particle shape.

    PubMed

    Chan, L W; Lee, C C; Heng, P W S

    2002-09-01

    Circularity, aspect ratio, modelx, and pellips were employed to study the effects of process parameters, namely varying feed loads and rotational speeds of the classifier wheel, of the fluidized bed opposed jet mill on the shape of the micronized particles produced. The Shapiro-Wilk statistical test showed that 80.0% of the shape distributions of the four descriptors were not normal. Therefore, the Kruskal-Wallis test, which is a nonparametric statistical test, was employed to analyze the data. Micronized particles were more spherical and less elongated, as indicated respectively by higher median circularity and lower median modelx values when compared to unmilled lactose. These descriptors were able to indicate that the particles had been micronized. When feed loads of 250 and 350 g were used, increasing the rotational speed of the classifier wheel was found to bring about a decrease in span values of all the shape descriptors, indicating that the micronized particles were more uniform in shape. Micronized particles produced had lower median aspect ratio values than the unmilled lactose, whereas a higher feed load of 450 g resulted in the production of micronized particles that were less uniform in shape and more elliptical in nature, as reflected by the lower median pellips values. A higher feed load of 450 g caused a high level of impingement of particles on to the rotating classifier wheel, causing decreased classifier wheel efficiency, and this resulted in a less well-controlled micronization process. Thus, aspect ratio and pellips were sensitive to the changes in performance of the classifier wheel. The four shape descriptors were proposed to be used collectively as indicators for the monitoring of the micronization process.

  18. 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.

  19. Three-Wheel Brush-Wheel Sampler

    NASA Technical Reports Server (NTRS)

    Duckworth, Geoffrey A.; Liu, Jun; Brown, Mark G.

    2010-01-01

    A new sampler is similar to a common snow blower, but is robust and effective in sample collection. The brush wheels are arranged in a triangle shape, each driven by a brushless DC motor and planetary gearhead embedded in the wheel shaft. Its speed can be varied from 800 - 2,000 rpm, depending on the surface regolith resistance. The sample-collecting flow path, and internal features, are designed based on flow dynamics, and the sample-collecting rates have consistently exceeded the requirement under various conditions that span the range of expected surface properties. The brush-wheel sampler (BWS) is designed so that the flow channel is the main body of the apparatus, and links the brush-wheel assembly to the sample canister. The combination of the three brush wheels, the sample flow path, and the canister location make sample collection, storage, and transfer an easier task.

  20. 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…

  1. 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…

  2. Wheel Installation

    NASA Image and Video Library

    2010-07-07

    In this picture, the Curiosity rover sports a set of six new wheels. The wheels were installed on June 28 and 29 in the Spacecraft Assembly Facility at NASA Jet Propulsion Laboratory, Pasadena, Calif.

  3. Cart Wheels

    ERIC Educational Resources Information Center

    Peck, Edson R.

    1978-01-01

    This paper draws attention to cart wheels, two wheels rotating freely about a common axle and rolling on an inclined plane, both as a demonstration and as a satisfying application of dynamical analysis. (BB)

  4. Cart Wheels

    ERIC Educational Resources Information Center

    Peck, Edson R.

    1978-01-01

    This paper draws attention to cart wheels, two wheels rotating freely about a common axle and rolling on an inclined plane, both as a demonstration and as a satisfying application of dynamical analysis. (BB)

  5. Research on the 2-axis cup-wheel dressing technology of arc-diamond grinding wheel

    NASA Astrophysics Data System (ADS)

    Chang, X. L.; Wu, H. Y.; Peng, Y. F.

    2014-08-01

    The precision dressing of arc-diamond wheel is very hard, expensive and time-consuming because of the super-hard diamond particles and complicated geometrical shape. This paper aims to investigate the cup-wheel dressing technology to realize the high-efficiency regeneration of the arc-diamond wheel. A two-axis cup-wheel dressing technique for precision dressing arc-diamond wheel was suggested and tested. The dressing mechanism of 2-axis cup-wheel was studied. The dressing algorithm and error compensation method were further investigated to improve the dressing precision and efficiency. The experimental results show that the 2-axis cup-wheel dressing technique is valid and applicable to realize the precision dressing of arc-diamond wheel. The machined optical surface condition was apparently improved with the cup-wheel dressed diamond wheel and even became much better when the error compensation algorithm was performed on the arc-diamond wheel.

  6. 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.

  7. Uranium and manganese assembled in a wheel-shaped nanoscale single-molecule magnet with high spin-reversal barrier

    NASA Astrophysics Data System (ADS)

    Mougel, Victor; Chatelain, Lucile; Pécaut, Jacques; Caciuffo, Roberto; Colineau, Eric; Griveau, Jean-Christophe; Mazzanti, Marinella

    2012-12-01

    Discrete molecular compounds that exhibit both magnetization hysteresis and slow magnetic relaxation below a characteristic ‘blocking’ temperature are known as single-molecule magnets. These are promising for applications including memory devices and quantum computing, but require higher spin-inversion barriers and hysteresis temperatures than currently achieved. After twenty years of research confined to the d- block transition metals, scientists are moving to the f-block to generate these properties. We have now prepared, by cation-promoted self-assembly, a large 5f-3d U12Mn6 cluster that adopts a wheel topology and exhibits single-molecule magnet behaviour. This uranium-based molecular wheel shows an open magnetic hysteresis loop at low temperature, with a non-zero coercive field (below 4 K) and quantum tunnelling steps (below 2.5 K), which suggests that uranium might indeed provide a route to magnetic storage devices. This molecule also represents an interesting model for actinide nanoparticles occurring in the environment and in spent fuel separation cycles.

  8. Bicycle Wheel

    NASA Technical Reports Server (NTRS)

    1991-01-01

    An aerodynamic bicycle wheel developed by two DuPont engineers and a California company incorporates research into NASA airfoils. Computer modeling was accomplished with MSC/NASTRAN. Each of the three spokes in the wheel is, in effect, an airfoil, maximizing aerodynamic efficiency for racing.

  9. Effect of chain shape on the self-assembly of bioinspired block copolymers

    NASA Astrophysics Data System (ADS)

    Rosales, Adrianne M.; Murnen, Hannah K.; Zuckermann, Ronald N.; Segalman, Rachel A.

    2012-02-01

    Polymer chain shape has been shown to affect both polymer properties and block copolymer self-assembly. Polypeptoids, a class of sequence-specific bioinspired polymer, have a chain shape that can be tuned by the introduction of monomers with bulky, chiral side chains, allowing one to change the polymer conformation while preserving the chemical nature of the side chains. Here, it is shown that introducing chiral, aromatic monomers into the polypeptoid chain increases the glass transition by 20 C for a chiral, helical polypeptoid compared to its achiral, non-structured analog. Incorporation of these polypeptoids into block copolymers with poly(methyl acrylate) enables a systematic study of the effect of chain shape while maintaining similar enthalpic interactions. For two otherwise analogous block copolymers, conformational asymmetry is shown to affect both the morphological domain spacing and the order-disorder transition temperature. Future work will focus on interfacial segregation experiments to determine the effect of conformational asymmetry on the Flory-Huggins parameter.

  10. Myosin light chain phosphorylation is correlated with cold-induced changes in platelet shape.

    PubMed

    Kawakami, H; Higashihara, M; Ohsaka, M; Miyazaki, K; Ikebe, M; Hirano, H

    2001-12-01

    Chilling induces shape changes in platelets from disks to spheres with abundant filopodia. Such changes were time-dependent and correlated well with the phosphorylation of 20-kDa myosin light chain (LC20). Both the shape changes and the phosphorylation were reversible. After the platelets had been chilled, myosin became incorporated into the Triton X-insoluble fraction. When the chilled platelets were immunocytochemically stained, anti-myosin antibody was localized with filamentous structures inside the filopodia. These results suggest that LC20 phosphorylation and subsequent interactions with actin filaments play a crucial role in the cold-induced changes in platelet shape and in the formation of filopodia.

  11. Wheels Spinning

    NASA Image and Video Library

    2010-07-13

    This image was taken in the cleanroom where NASA Curiosity rover is being assembled. It shows the rover, which is about the size of an SUV, hoisted on a white lift, with its black wheels suspended in the air.

  12. A factorization-based approach for articulated nonrigid shape, motion and kinematic chain recovery from video.

    PubMed

    Yan, Jingyu; Pollefeys, Marc

    2008-05-01

    Recovering articulated shape and motion, especially human body motion, from video is a challenging problem with a wide range of applications in medical study, sport analysis and animation, etc. Previous work on articulated motion recovery generally requires prior knowledge of the kinematic chain and usually does not concern the recovery of the articulated shape. The non-rigidity of some articulated part, e.g. human body motion with nonrigid facial motion, is completely ignored. We propose a factorization-based approach to recover the shape, motion and kinematic chain of an articulated object with nonrigid parts altogether directly from video sequences under a unified framework. The proposed approach is based on our modeling of the articulated non-rigid motion as a set of intersecting motion subspaces. A motion subspace is the linear subspace of the trajectories of an object. It can model a rigid or non-rigid motion. The intersection of two motion subspaces of linked parts models the motion of an articulated joint or axis. Our approach consists of algorithms for motion segmentation, kinematic chain building, and shape recovery. It handles outliers and can be automated. We test our approach through synthetic and real experiments and demonstrate how to recover articulated structure with non-rigid parts via a single-view camera without prior knowledge of its kinematic chain.

  13. U-shaped conformation of alkyl chains bound to a synthetic receptor cucurbit[8]uril.

    PubMed

    Ko, Young Ho; Kim, Youngkook; Kim, Hyunuk; Kim, Kimoon

    2011-02-01

    The behavior of a series of alkanes bound to the molecular host cucurbit[8]uril (CB[8]) has been systematically studied by 2D (1)H NMR spectroscopy and isothermal titration calorimetry (ITC). CB[8] and alkyltrimethylammonium (C(m) TA(+), (CH(3))(3)N(+)C(m)H(2m+1), m=6-16) form 1:1 host-guest complexes with a high binding constant (K≈10(6) m(-1)). The shortest hexyl chain of C(6)TA(+) can be fully encapsulated in an extended conformation inside the CB[8] cavity, which is driven by both enthalpy and entropy. However, for the longer aliphatic chains, C(8)-C(16), the long alkyl tails take a U-shaped conformation inside the cavity, and their complexation is dominantly or almost exclusively enthalpy-driven, owing to the increased van der Waals contact between the folded aliphatic chain and the inner wall of the host cavity. As the chain length increases from C(8) to C(16), the ammonium head group of the guests moves away from the portal of CB[8] while the long aliphatic tails maintain the U-shaped conformation inside the cavity. The complexation of C(m)TA(+) with CB[8] follows the enthalpy-entropy compensation rule commonly observed in molecular recognition systems. For example, among the guest molecules, C(12)TA(+) shows the highest enthalpic gain (most favorable), owing to the large van der Waals contact between the guest and the host cavity, and at the same time the most unfavorable entropic contribution, owing to the severe conformational restriction of the U-shaped alkyl chain inside the host. The enthalpy-entropy compensation plot for the complexation suggests large conformational changes of the long alkyl chains and extensive dehydration associated with the inclusion complex formation.

  14. Anionic surfactant with hydrophobic and hydrophilic chains for nanoparticle dispersion and shape memory polymer nanocomposites.

    PubMed

    Iijima, Motoyuki; Kobayakawa, Murino; Yamazaki, Miwa; Ohta, Yasuhiro; Kamiya, Hidehiro

    2009-11-18

    An anionic surfactant comprising a hydrophilic poly(ethylene glycol) (PEG) chain, hydrophobic alkyl chain, and polymerizable vinyl group was synthesized as a capping agent of nanoparticles. TiO(2) nanoparticles modified by this surfactant were completely dispersible in various organic solvents with a wide range of polarities, such as nitriles, alcohols, ketones, and acetates. Furthermore, these particles were found to be dispersible in various polymers with different properties, such as thermosetting epoxy resins and radical polymerized poly(methylmethacrylate) (PMMA). A polymer composite of surface-modified TiO(2) nanoparticles in epoxy resins prepared by using the developed surfactant also possessed temperature-induced shape memory properties.

  15. Chopping-Wheel Optical Attenuator

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    1988-01-01

    Star-shaped rotating chopping wheel provides adjustable time-averaged attenuation of narrow beam of light without changing length of optical path or spectral distribution of light. Duty cycle or attenuation factor of chopped beam controlled by adjusting radius at which beam intersects wheel. Attenuation factor independent of wavelength. Useful in systems in which chopping frequency above frequency-response limits of photodetectors receiving chopped light. Used in systems using synchronous detection with lock-in amplifiers.

  16. Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

    PubMed Central

    El-Safty, Sherif A.; Shenashen, Mohamed A.; Sakai, Masaru; Elshehy, Emad; Halada, Kohmei

    2015-01-01

    Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobaltmetals. PMID:26709467

  17. Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores.

    PubMed

    El-Safty, Sherif A; Shenashen, Mohamed A; Sakai, Masaru; Elshehy, Emad; Halada, Kohmei

    2015-12-06

    Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

  18. Size, shape, and diffusivity of a single Debye-Hückel polyelectrolyte chain in solution.

    PubMed

    Soysa, W Chamath; Dünweg, B; Prakash, J Ravi

    2015-08-14

    Brownian dynamics simulations of a coarse-grained bead-spring chain model, with Debye-Hückel electrostatic interactions between the beads, are used to determine the root-mean-square end-to-end vector, the radius of gyration, and various shape functions (defined in terms of eigenvalues of the radius of gyration tensor) of a weakly charged polyelectrolyte chain in solution, in the limit of low polymer concentration. The long-time diffusivity is calculated from the mean square displacement of the centre of mass of the chain, with hydrodynamic interactions taken into account through the incorporation of the Rotne-Prager-Yamakawa tensor. Simulation results are interpreted in the light of the Odjik, Skolnick, Fixman, Khokhlov, and Khachaturian blob scaling theory (Everaers et al., Eur. Phys. J. E 8, 3 (2002)) which predicts that all solution properties are determined by just two scaling variables-the number of electrostatic blobs X and the reduced Debye screening length, Y. We identify three broad regimes, the ideal chain regime at small values of Y, the blob-pole regime at large values of Y, and the crossover regime at intermediate values of Y, within which the mean size, shape, and diffusivity exhibit characteristic behaviours. In particular, when simulation results are recast in terms of blob scaling variables, universal behaviour independent of the choice of bead-spring chain parameters, and the number of blobs X, is observed in the ideal chain regime and in much of the crossover regime, while the existence of logarithmic corrections to scaling in the blob-pole regime leads to non-universal behaviour.

  19. Controlled Shape Memory Behavior of a Smectic Main-Chain Liquid Crystalline Elastomer

    DOE PAGES

    Li, Yuzhan; Pruitt, Cole; Rios, Orlando; ...

    2015-04-10

    Here, we describe how a smectic main-chain liquid crystalline elastomer (LCE), with controlled shape memory behavior, is synthesized by polymerizing a biphenyl-based epoxy monomer with an aliphatic carboxylic acid curing agent. Microstructures of the LCEs, including their liquid crystallinity and cross-linking density, are modified by adjusting the stoichiometric ratio of the reactants to tailor the thermomechanical properties and shape memory behavior of the material. Thermal and liquid crystalline properties of the LCEs, characterized using differential scanning calorimetry and dynamic mechanical analysis, and structural analysis, performed using small-angle and wide-angle X-ray scattering, show that liquid crystallinity, cross-linking density, and network rigiditymore » are strongly affected by the stoichiometry of the curing reaction. With appropriate structural modifications it is possible to tune the thermal, dynamic mechanical, and thermomechanical properties as well as the shape memory and thermal degradation behavior of LCEs.« less

  20. Controlled Shape Memory Behavior of a Smectic Main-Chain Liquid Crystalline Elastomer

    SciTech Connect

    Li, Yuzhan; Pruitt, Cole; Rios, Orlando; Wei, Liqing; Rock, Mitch; Keum, Jong K.; McDonald, Armando G.; Kessler, Michael R.

    2015-04-10

    Here, we describe how a smectic main-chain liquid crystalline elastomer (LCE), with controlled shape memory behavior, is synthesized by polymerizing a biphenyl-based epoxy monomer with an aliphatic carboxylic acid curing agent. Microstructures of the LCEs, including their liquid crystallinity and cross-linking density, are modified by adjusting the stoichiometric ratio of the reactants to tailor the thermomechanical properties and shape memory behavior of the material. Thermal and liquid crystalline properties of the LCEs, characterized using differential scanning calorimetry and dynamic mechanical analysis, and structural analysis, performed using small-angle and wide-angle X-ray scattering, show that liquid crystallinity, cross-linking density, and network rigidity are strongly affected by the stoichiometry of the curing reaction. With appropriate structural modifications it is possible to tune the thermal, dynamic mechanical, and thermomechanical properties as well as the shape memory and thermal degradation behavior of LCEs.

  1. 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

  2. Influence of substrate potential shape on the dynamics of a sliding lubricant chain

    NASA Astrophysics Data System (ADS)

    Woulaché, Rosalie Laure; Vanossi, Andrea; Manini, Nicola

    2013-07-01

    We investigate the frictional sliding of an incommensurate chain of interacting particles confined in between two nonlinear on-site substrate potential profiles in relative motion. We focus here on the class of Remoissenet-Peyrard parametrized potentials VRP(x,s), whose shape can be varied continuously as a function of s, recovering the sine-Gordon potential as a particular case. The observed frictional dynamics of the system, crucially dependent on the mutual ratios of the three periodicities in the sandwich geometry, turns out to be significantly influenced also by the shape of the substrate potential. Specifically, variations of the shape parameter s affect significantly and not trivially the existence and robustness of the recently reported velocity quantization phenomena [A. Vanossi , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.97.056101 97, 056101 (2006)], where the chain center-of-mass velocity to the externally imposed relative velocity of the sliders stays pinned to exact “plateau” values for wide ranges of the dynamical parameters.

  3. Adjusting the Chain Gear

    NASA Astrophysics Data System (ADS)

    Koloc, Z.; Korf, J.; Kavan, P.

    The adjustment (modification) deals with gear chains intermediating (transmitting) motion transfer between the sprocket wheels on parallel shafts. The purpose of the adjustments of chain gear is to remove the unwanted effects by using the chain guide on the links (sliding guide rail) ensuring a smooth fit of the chain rollers into the wheel tooth gap.

  4. Kinesin-1 heavy chain mediates microtubule sliding to drive changes in cell shape.

    PubMed

    Jolly, Amber L; Kim, Hwajin; Srinivasan, Divya; Lakonishok, Margot; Larson, Adam G; Gelfand, Vladimir I

    2010-07-06

    Microtubules are typically observed to buckle and loop during interphase in cultured cells by an unknown mechanism. We show that lateral microtubule movement and looping is a result of microtubules sliding against one another in interphase Drosophila S2 cells. RNAi of the kinesin-1 heavy chain (KHC), but not dynein or the kinesin-1 light chain, eliminates these movements. KHC-dependent microtubule sliding powers the formation of cellular processes filled with parallel microtubule bundles. The growth of these cellular processes is independent of the actin cytoskeleton. We further observe cytoplasmic microtubule sliding in Xenopus and Ptk2 cells, and show that antibody inhibition of KHC in mammalian cells prevents sliding. We therefore propose that, in addition to its well established role in organelle transport, an important universal function of kinesin-1 is to mediate cytoplasmic microtubule-microtubule sliding. This provides the cell with a dedicated mechanism to transport long and short microtubule filaments and drive changes in cell shape.

  5. Dependence of micelle size and shape on detergent alkyl chain length and head group.

    PubMed

    Oliver, Ryan C; Lipfert, Jan; Fox, Daniel A; Lo, Ryan H; Doniach, Sebastian; Columbus, Linda

    2013-01-01

    Micelle-forming detergents provide an amphipathic environment that can mimic lipid bilayers and are important tools for solubilizing membrane proteins for functional and structural investigations in vitro. However, the formation of a soluble protein-detergent complex (PDC) currently relies on empirical screening of detergents, and a stable and functional PDC is often not obtained. To provide a foundation for systematic comparisons between the properties of the detergent micelle and the resulting PDC, a comprehensive set of detergents commonly used for membrane protein studies are systematically investigated. Using small-angle X-ray scattering (SAXS), micelle shapes and sizes are determined for phosphocholines with 10, 12, and 14 alkyl carbons, glucosides with 8, 9, and 10 alkyl carbons, maltosides with 8, 10, and 12 alkyl carbons, and lysophosphatidyl glycerols with 14 and 16 alkyl carbons. The SAXS profiles are well described by two-component ellipsoid models, with an electron rich outer shell corresponding to the detergent head groups and a less electron dense hydrophobic core composed of the alkyl chains. The minor axis of the elliptical micelle core from these models is constrained by the length of the alkyl chain, and increases by 1.2-1.5 Å per carbon addition to the alkyl chain. The major elliptical axis also increases with chain length; however, the ellipticity remains approximately constant for each detergent series. In addition, the aggregation number of these detergents increases by ∼16 monomers per micelle for each alkyl carbon added. The data provide a comprehensive view of the determinants of micelle shape and size and provide a baseline for correlating micelle properties with protein-detergent interactions.

  6. Dependence of Micelle Size and Shape on Detergent Alkyl Chain Length and Head Group

    PubMed Central

    Oliver, Ryan C.; Lipfert, Jan; Fox, Daniel A.; Lo, Ryan H.; Doniach, Sebastian; Columbus, Linda

    2013-01-01

    Micelle-forming detergents provide an amphipathic environment that can mimic lipid bilayers and are important tools for solubilizing membrane proteins for functional and structural investigations in vitro. However, the formation of a soluble protein-detergent complex (PDC) currently relies on empirical screening of detergents, and a stable and functional PDC is often not obtained. To provide a foundation for systematic comparisons between the properties of the detergent micelle and the resulting PDC, a comprehensive set of detergents commonly used for membrane protein studies are systematically investigated. Using small-angle X-ray scattering (SAXS), micelle shapes and sizes are determined for phosphocholines with 10, 12, and 14 alkyl carbons, glucosides with 8, 9, and 10 alkyl carbons, maltosides with 8, 10, and 12 alkyl carbons, and lysophosphatidyl glycerols with 14 and 16 alkyl carbons. The SAXS profiles are well described by two-component ellipsoid models, with an electron rich outer shell corresponding to the detergent head groups and a less electron dense hydrophobic core composed of the alkyl chains. The minor axis of the elliptical micelle core from these models is constrained by the length of the alkyl chain, and increases by 1.2–1.5 Å per carbon addition to the alkyl chain. The major elliptical axis also increases with chain length; however, the ellipticity remains approximately constant for each detergent series. In addition, the aggregation number of these detergents increases by ∼16 monomers per micelle for each alkyl carbon added. The data provide a comprehensive view of the determinants of micelle shape and size and provide a baseline for correlating micelle properties with protein-detergent interactions. PMID:23667481

  7. Shape control of the magnetic iron oxide nanoparticles under different chain length of reducing agents

    SciTech Connect

    Ngoi, Kuan Hoon; Chia, Chin-Hua Zakaria, Sarani; Chiu, Wee Siong

    2015-09-25

    We report on the effect of using reducing agents with different chain-length on the synthesis of iron oxide nanoparticles by thermal decomposition of iron (III) acetylacetonate in 1-octadecene. This modification allows us to control the shape of nanoparticles into spherical and cubic iron oxide nanoparticles. The highly monodisperse 14 nm spherical nanoparticles are obtained under 1,2-dodecanediol and average 14 nm edge-length cubic iron oxide nanoparticles are obtained under 1,2-tetradecanediol. The structural characterization such as transmission electron microscope (TEM) and X-ray diffraction (XRD) shows similar properties between two particles with different shapes. The vibrating sample magnetometer (VSM) shows no significant difference between spherical and cubic nanoparticles, which are 36 emu/g and 37 emu/g respectively and superparamagnetic in nature.

  8. Mitochondrial Cristae Shape Determines Respiratory Chain Supercomplexes Assembly and Respiratory Efficiency

    PubMed Central

    Cogliati, Sara; Frezza, Christian; Soriano, Maria Eugenia; Varanita, Tatiana; Quintana-Cabrera, Ruben; Corrado, Mauro; Cipolat, Sara; Costa, Veronica; Casarin, Alberto; Gomes, Ligia C.; Perales-Clemente, Ester; Salviati, Leonardo; Fernandez-Silva, Patricio; Enriquez, Jose A.; Scorrano, Luca

    2013-01-01

    Summary Respiratory chain complexes assemble into functional quaternary structures called supercomplexes (RCS) within the folds of the inner mitochondrial membrane, or cristae. Here, we investigate the relationship between respiratory function and mitochondrial ultrastructure and provide evidence that cristae shape determines the assembly and stability of RCS and hence mitochondrial respiratory efficiency. Genetic and apoptotic manipulations of cristae structure affect assembly and activity of RCS in vitro and in vivo, independently of changes to mitochondrial protein synthesis or apoptotic outer mitochondrial membrane permeabilization. We demonstrate that, accordingly, the efficiency of mitochondria-dependent cell growth depends on cristae shape. Thus, RCS assembly emerges as a link between membrane morphology and function. PMID:24055366

  9. Statistical geometry of lattice chain polymers with voids of defined shapes: sampling with strong constraints.

    PubMed

    Lin, Ming; Chen, Rong; Liang, Jie

    2008-02-28

    Proteins contain many voids, which are unfilled spaces enclosed in the interior. A few of them have shapes compatible to ligands and substrates and are important for protein functions. An important general question is how the need for maintaining functional voids is influenced by, and affects other aspects of proteins structures and properties (e.g., protein folding stability, kinetic accessibility, and evolution selection pressure). In this paper, we examine in detail the effects of maintaining voids of different shapes and sizes using two-dimensional lattice models. We study the propensity for conformations to form a void of specific shape, which is related to the entropic cost of void maintenance. We also study the location that voids of a specific shape and size tend to form, and the influence of compactness on the formation of such voids. As enumeration is infeasible for long chain polymer, a key development in this work is the design of a novel sequential Monte Carlo strategy for generating large number of sample conformations under very constraining restrictions. Our method is validated by comparing results obtained from sampling and from enumeration for short polymer chains. We succeeded in accurate estimation of entropic cost of void maintenance, with and without an increasing number of restrictive conditions, such as loops forming the wall of void with fixed length, with additionally fixed starting position in the sequence. Additionally, we have identified the key structural properties of voids that are important in determining the entropic cost of void formation. We have further developed a parametric model to predict quantitatively void entropy. Our model is highly effective, and these results indicate that voids representing functional sites can be used as an improved model for studying the evolution of protein functions and how protein function relates to protein stability.

  10. Statistical geometry of lattice chain polymers with voids of defined shapes: Sampling with strong constraints

    NASA Astrophysics Data System (ADS)

    Lin, Ming; Chen, Rong; Liang, Jie

    2008-02-01

    Proteins contain many voids, which are unfilled spaces enclosed in the interior. A few of them have shapes compatible to ligands and substrates and are important for protein functions. An important general question is how the need for maintaining functional voids is influenced by, and affects other aspects of proteins structures and properties (e.g., protein folding stability, kinetic accessibility, and evolution selection pressure). In this paper, we examine in detail the effects of maintaining voids of different shapes and sizes using two-dimensional lattice models. We study the propensity for conformations to form a void of specific shape, which is related to the entropic cost of void maintenance. We also study the location that voids of a specific shape and size tend to form, and the influence of compactness on the formation of such voids. As enumeration is infeasible for long chain polymer, a key development in this work is the design of a novel sequential Monte Carlo strategy for generating large number of sample conformations under very constraining restrictions. Our method is validated by comparing results obtained from sampling and from enumeration for short polymer chains. We succeeded in accurate estimation of entropic cost of void maintenance, with and without an increasing number of restrictive conditions, such as loops forming the wall of void with fixed length, with additionally fixed starting position in the sequence. Additionally, we have identified the key structural properties of voids that are important in determining the entropic cost of void formation. We have further developed a parametric model to predict quantitatively void entropy. Our model is highly effective, and these results indicate that voids representing functional sites can be used as an improved model for studying the evolution of protein functions and how protein function relates to protein stability.

  11. Imaging Metastasis Using an Integrin-Targeting Chain-Shaped Nanoparticle

    PubMed Central

    Peiris, Pubudu M.; Toy, Randall; Doolittle, Elizabeth; Pansky, Jenna; Abramowski, Aaron; Tam, Morgan; Vicente, Peter; Tran, Emily; Hayden, Elliott; Camann, Andrew; Mayer, Aaron; Erokwu, Bernadette O.; Berman, Zachary; Wilson, David; Baskaran, Harihara; Flask, Chris A.; Keri, Ruth A.; Karathanasis, Efstathios

    2012-01-01

    While the enhanced permeability and retention effect may promote the preferential accumulation of nanoparticles into well-vascularized primary tumors, it is ineffective in the case of metastases hidden within a large population of normal cells. Due to their small size, high dispersion to organs, and low vascularization, metastatic tumors are less accessible to targeted nanoparticles. To tackle these challenges, we designed a nanoparticle for vascular targeting based on an αvβ3 integrin-targeted nanochain particle composed of four iron oxide nanospheres chemically linked in a linear assembly. The chain-shaped nanoparticles enabled enhanced ‘sensing’ of the tumor-associated remodeling of the vascular bed offering increased likelihood of specific recognition of metastatic tumors. Compared to spherical nanoparticles, the chain-shaped nanoparticles resulted in superior targeting of αvβ3 integrin due to geometrically enhanced multivalent docking. We performed multimodal in vivo imaging (Fluorescence Molecular Tomography and Magnetic Resonance Imaging) in a non-invasive and quantitative manner, which showed that the nanoparticles targeted metastases in the liver and lungs with high specificity in a highly aggressive breast tumor model in mice. PMID:23005348

  12. Fifth wheel

    NASA Technical Reports Server (NTRS)

    Albrecht, W. P.; Sparks, R. H. (Inventor)

    1976-01-01

    An improved fifth wheel for a tractor trailer rig, characterized by a first subassembly including a wear plate was developed and modified to be mounted on a downwardly facing surface of a trailer. A king pin projected normally therefrom, and a second subassembly is adapted to be pivotally mounted on an upwardly facing surface of a tractor. The king pin is brought into contiguous relation with the first sub assembly. A receiver for capturing the king pin is included along with a safety means responsive to a failure of the king pin or its latching mechanism for joining the first subassembly with the second subassembly.

  13. 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.

  14. 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.

  15. Submerged water wheel

    SciTech Connect

    Frisz, J. O.

    1985-11-05

    A water wheel for operating fully submerged in an ocean current has a rotating frame member supported on the ocean floor for rotation about a vertical axis. The frame member supports a plurality of vertically extending vanes, each vane being rotatably supported on the frame for limited rotation about a vertical axis. It has a hydrofoil shape in cross-section with the axis of rotation parallel to the leading and trailing edges. Rotation of the vanes is limited relative to the frame by a hydraulic piston control system and shock absorbers.

  16. Phase-shift-controlled logic gates in Y-shaped nonlinearly coupled chains

    NASA Astrophysics Data System (ADS)

    Assunção, T. F.; Nascimento, E. M.; Sombra, A. S. B.; Lyra, M. L.

    2016-02-01

    We introduce a model system composed of two input discrete chains nonlinearly coupled to a single output chain which mimics the geometry of Y-shaped carbon nanotubes, photonic crystal wave guides, and DNA junctions. We explore the capability of the proposed system to perform logic gate operations based on the transmission of phase-shifted harmonic incoming waves. Within a tight-binding approach, we determine the exact transmission spectrum which exhibits a nonlinear induced bistability. Using a digitalization scheme of the output signal based on amplitude modulation, we show that AND, OR, and XOR logic operations can be achieved. Nonlinearity strongly favors the realization of logic operations in the regime of large wavelengths, while phase shifting is required for the OR logic gate to be realizable. A detailed analysis of the contrast ratio shows that optimal operation of the AND and OR logic gates takes place when the nonlinear response is the predominant physical property distinguishing the coupling and regular sites. These results point towards the possibility of Y-branched junctions to perform logic operations based on the transmission of traveling waves.

  17. Kinesin-1 heavy chain mediates microtubule sliding to drive changes in cell shape

    PubMed Central

    Jolly, Amber L.; Kim, Hwajin; Srinivasan, Divya; Lakonishok, Margot; Larson, Adam G.; Gelfand, Vladimir I.

    2010-01-01

    Microtubules are typically observed to buckle and loop during interphase in cultured cells by an unknown mechanism. We show that lateral microtubule movement and looping is a result of microtubules sliding against one another in interphase Drosophila S2 cells. RNAi of the kinesin-1 heavy chain (KHC), but not dynein or the kinesin-1 light chain, eliminates these movements. KHC-dependent microtubule sliding powers the formation of cellular processes filled with parallel microtubule bundles. The growth of these cellular processes is independent of the actin cytoskeleton. We further observe cytoplasmic microtubule sliding in Xenopus and Ptk2 cells, and show that antibody inhibition of KHC in mammalian cells prevents sliding. We therefore propose that, in addition to its well established role in organelle transport, an important universal function of kinesin-1 is to mediate cytoplasmic microtubule–microtubule sliding. This provides the cell with a dedicated mechanism to transport long and short microtubule filaments and drive changes in cell shape. PMID:20566873

  18. 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

  19. The Influences of the Wheel Profiles on the Wheel Wear and Vibrational Characteristics of the Passenger Cars Running on the Seoul-Pusan Conventional Line

    NASA Astrophysics Data System (ADS)

    Kang, Bu-Byoung; Lee, Chan-Woo

    Wheels of the railway vehicle play the important role for driving train through wheel-rail interaction. Especially wheel profile is one of the most important design factors to rule the running stability and safety of train. Accordingly maintenance of wheel like wheel profile control is also very important for securing safety and stability of train operation. This study presents the wheel wear measurement results of Saemaeul running on the conventional line. The train set included three different cars which have different shape of wheel profile including KNR profile currently used in Saemaeul. Train set was operated on Seoul-Pusan line with fixed train set formation for commercial service. Wheel wear measurements were performed periodically. We can find the influence of wheel profile on the wheel wear of the train running on the conventional line through the measurement results.

  20. Reaction wheel assembly

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The fabrication and testing of three reaction wheels with associated drive and system monitoring electronics and brushless dc spin motors are discussed; the wheels are intended for use in a teleoperator simulator. Test results are included as graphs.

  1. Cylindrical Wire Electrical Discharge Machining of Metal Bond Diamond Wheels- Part II: Wheel Wear Mechanism

    SciTech Connect

    McSpadden, SB

    2002-01-22

    The use of stereo scanning Electron Microscopy (SEM) to investigate the wear mechanism of the wire EDM true metal bond diamond wheel for ceramic grinding is presented. On the grinding wheel, a wedge-shape removal part was machined to enable the examination and measurement of the worn wheel surfaces using the stereo SEM. The stereo SEM was calibrated by comparing results of depth profile of a wear groove with the profilometer measurements. On the surface of the grinding wheel after wire EDM truing and before grinding, the diamond protruding heights were measured in the level of 35 {micro}m, comparing to the 54 {micro}m average size of the diamond in the grinding wheel. The gap between the EDM wire and rotating grinding wheel is estimated to be about 35 to 40 {micro}m. This observation indicates that, during the wire EDM, electrical sparks occur between the metal bond and EDM wire, which leaves the diamond protruding in the gap between the wire and wheel. The protruding diamond is immediately fractured at the start of the grinding process, even under a light grinding condition. After heavy grinding, the grinding wheel surface and the diamond protrusion heights are also investigated using the stereo SEM. The height of diamond protrusion was estimated in the 5 to 15 {micro}m range. This study has demonstrated the use of stereo SEM as a metrology tool to study the grinding wheel surface.

  2. Size and temperature dependence of the line shape of ESR spectra of the XXZ antiferromagnetic chain

    NASA Astrophysics Data System (ADS)

    Ikeuchi, Hiroki; De Raedt, Hans; Bertaina, Sylvain; Miyashita, Seiji

    2017-01-01

    The electron spin resonance spectrum of the XXZ spin chain with finite length shows a double-peak structure at high temperatures around the electron paramagnetic resonance (EPR) frequency. This fact has been pointed out by direct numerical methods [S. El Shawish, O. Cépas, and S. Miyashita, Phys. Rev. B 81, 224421 (2010), 10.1103/PhysRevB.81.224421; H. Ikeuchi, H. De Raedt, S. Bertaina, and S. Miyashita, Phys. Rev. B 92, 214431 (2015), 10.1103/PhysRevB.92.214431]. The question of whether the double-peak structure survives in the thermodynamics is of particular interest. We study the size dependence of the line shape, including the even-odd effect. It is found that the peaks forming the double-peak structure are assigned to individual resonances, each of which is specified by the magnetizations of the resonating states (M ,M -1 ) . To understand dependences, we decompose the spectrum into contributions from transitions specified by the magnetization, and we characterize the structure of the spectrum by individual contributions. We analyze the size dependence of each contribution individually by extending the moment method introduced by M. Brockman et al. to each component, and we find that the mean of each peak approaches the paramagnetic resonance point with 1 /N (where N is the length of the chain), which indicates that the separation of the peaks of the double-peak structure also vanishes inversely with the system size. We also study the temperature dependence of the structure. At low temperatures, the spectrum has a single peak with a finite width at a position with a finite shift from the frequency of EPR, as pointed out by the analysis of field-theoretical works [M. Oshikawa and I. Affleck, Phys. Rev. Lett. 82, 5136 (1999), 10.1103/PhysRevLett.82.5136]. The study of the temperature dependence of the spectrum shows how the high-temperature spectrum changes to the low-temperature one with a drastic broadening of the spectrum.

  3. 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

  4. From bicycle chain ring shape to gear ratio: algorithm and examples.

    PubMed

    van Soest, A J

    2014-01-03

    A simple model of the bicycle drive system with a non-circular front chain ring is proposed and an algorithm is devised for calculation of the corresponding Gear Ratio As a Function Of Crank Angle (GRAFOCA). It is shown that the true effective radius of the chain ring is always the perpendicular distance between the crank axis and the line through the chain segment between the chain ring and the cog. It is illustrated that the true effective radius of the chain ring at any crank angle may differ substantially from the maximum vertical distance between the crank axis and the chain ring circumference that is used as a proxy for the effective chain ring radius in several studies; in particular, the crank angle at which the effective chain ring radius is maximal as predicted from the latter approach may deviate by as much as 0.30 rad from the true value. The algorithm proposed may help in designing chain rings that achieve the desired GRAFOCA.

  5. Grazers and vitamins shape chain formation in a bloom-forming dinoflagellate, Cochlodinium polykrikoides.

    PubMed

    Jiang, Xiaodong; Lonsdale, Darcy J; Gobler, Christopher J

    2010-10-01

    Predators influence the phenotype of prey through both natural selection and induction. We investigated the effects of grazers and nutrients on chain formation in a dinoflagellate, Cochlodinium polykrikoides, which forms dense blooms and has deleterious effects on marine ecosystems around the world. Field populations of C. polykrikoides formed longer chains than laboratory cultures without grazers. In the field, chain length of C. polykrikoides was positively correlated with the abundance of the copepod Acartia tonsa. Chain length of C. polykrikoides increased when exposed to live females of A. tonsa or its fresh (<24 h post-isolation) exudates for 48 h. These results suggest that dissolved chemical cues released by A. tonsa induce chain formation in C. polykrikoides. Ingestion rate of A. tonsa on four-cell chains of C. polykrikoides was lower than on single cells, suggesting that chain formation may be an effective anti-grazing defense. Finally, nutrient amendment experiments demonstrated that vitamins (B(1), B(7), and B(12)) increased the chain length of C. polykrikoides both singly and collectively, while trace metals and inorganic nutrients did not, showing that vitamins may also influence chain formation in this species.

  6. High-yield syntheses and reactivity studies of Fe10 "ferric wheels": structural, magnetic, and computational characterization of a star-shaped Fe8 complex.

    PubMed

    Stamatatos, Theocharis C; Christou, Alexander G; Mukherjee, Shreya; Poole, Katye M; Lampropoulos, Christos; Abboud, Khalil A; O'Brien, Ted A; Christou, George

    2008-10-06

    Convenient, high-yield routes have been developed to [Fe 10(OMe) 20(O 2CR) 10] ( 1) "ferric wheels" involving the alcoholysis of [Fe 3O(O 2CR) 6(H 2O) 3] (+) salts in MeOH in the presence of NEt 3. Reactivity studies have established [Fe 10(OMe) 20(O 2CMe) 10] ( 1a) to undergo clean carboxylate substitution with a variety of other RCO 2H groups to the corresponding [Fe 10(OMe) 20(O 2CR) 10] product. In contrast, the reaction with phenol causes a nuclearity change to give a smaller [Fe 8(OH) 4(OPh) 8(O 2CR) 12] ( 2) wheel. Similarly, reactions of [Fe 10(OMe) 20(O 2CR) 10] with the bidentate chelate ethylenediamine (en) cause a structural change to give either [Fe 8O 5(O 2CMe) 8(en) 8](ClO 4) 6 ( 3) or [Fe 2O(O 2CBu (t))(en) 4](NO 3) 3 ( 4), depending on conditions. Complex 3 possesses a "Christmas-star" Fe 8 topology comprising a central planar [Fe 4(mu 4-O)] (10+) square subunit edge-fused to four oxide-centered [Fe 3(mu 3-O)] (7+) triangular units. Variable-temperature, solid-state dc and ac magnetization studies on complexes 1a- 4 in the 5.0-300 K range established that all the complexes possess an S = 0 ground state. The magnetic susceptibility data for 4 were fit to the theoretical chi M versus T expression derived by the use of an isotropic Heisenberg spin Hamiltonian and the Van Vleck equation, and this revealed an antiferromagnetic exchange parameter with a value of J = -107.7(5) cm (-1). This value is consistent with that predicted by a previously published magnetostructural relationship. Theoretically computed values of the exchange constants in 3 were obtained with the ZILSH method, and the pattern of spin frustration within its core and the origin of its S = 0 ground state have been analyzed in detail.

  7. 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 shape. Once thus deployed, the CHEM structure can be rigidified by cooling below Tg to the glassy state. The structure could be subsequently reheated above Tg and recompacted. The compaction/deployment/rigidification cycle could be repeated as many times as needed.

  8. Effect of wheel load on wheel vibration and sound radiation

    NASA Astrophysics Data System (ADS)

    Han, Jian; Wang, Ruiqian; Wang, Di; Guan, Qinghua; Zhang, Yumei; Xiao, Xinbiao; Jin, Xuesong

    2015-01-01

    The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation. The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t, the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the effect of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research.

  9. 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.

  10. Statistical mechanics of a polymer chain attached to the interface of a cone-shaped channel

    NASA Astrophysics Data System (ADS)

    Kumar, Sanjay; Kumar, Sanjiv; Giri, Debaprasad; Nath, Shesh

    2017-04-01

    A polymer chain confined in nano-scale geometry has been used to investigate the underlying mechanism of Nuclear Pore Complex (NPC), where transport of cargoes is directional. It was shown here that depending on the solvent quality (good or poor) across the channel, a polymer chain can be either inside or outside the channel or both. Exact results based on the short chain revealed that a slight variation in the solvent quality can drag the polymer chain inside the pore and vice versa similarly to one seen in NPC. Furthermore, we also report the absence of crystalline (highly dense) state when the pore size is less than a certain value, which may have potential application in packaging of DNA inside the preformed viral proheads.

  11. Ligand and Metal Effects on the Stability and Adsorption Properties of an Isoreticular Series of MOFs Based on T-Shaped Ligands and Paddle-Wheel Secondary Building Units.

    PubMed

    Xiong, Ying; Fan, Yan-Zhong; Damasceno Borges, Daiane; Chen, Cheng-Xia; Wei, Zhang-Wen; Wang, Hai-Ping; Pan, Mei; Jiang, Ji-Jun; Maurin, Guillaume; Su, Cheng-Yong

    2016-11-02

    The synthesis of stable porous materials with appropriate pore size and shape for desired applications remains challenging. In this work a combined experimental/computational approach has been undertaken to tune the stability under various conditions and the adsorption behavior of a series of MOFs by subtle control of both the nature of the metal center (Co(2+) , Cu(2+) , and Zn(2+) ) and the pore surface by the functionalization of the organic linkers with amido and N-oxide groups. In this context, six isoreticular MOFs based on T-shaped ligands and paddle-wheel units with ScD0.33 topology have been synthesized. Their stabilities have been systematically investigated along with their ability to adsorb a wide range of gases (N2 , CO2 , CH4 , CO, H2, light hydrocarbons (C1 -C4 )) and vapors (alcohols and water). This study has revealed that the MOF frameworks based on Cu(2+) are more stable than their Co(2+) and Zn(2+) analogues, and that the N-oxide ligand endows the MOFs with a higher affinity for CO2 leading to excellent selectivity for this gas over other species.

  12. Spatial problem-solving in a wheel-shaped maze: quantitative and qualitative analyses of the behavioural changes following damage to the hippocampus in the rat.

    PubMed

    Buhot, M C; Chapuis, N; Scardigli, P; Herrmann, T

    1991-07-01

    The behaviour of sham-operated rats and rats with damage to the dorsal hippocampus was compared in a complex spatial problem-solving task using a 'hub-spoke-rim' wheel type maze. Compared to the classical Olton 8-arm radial maze and Morris water maze, this apparatus presents the animal with a series of possible alternative routes both direct and indirect to the goal (food). The task included 3 main stages: exploration, feeding and testing, as do the classic problem-solving tasks. During exploration, hippocampal rats were found to be more active than sham rats. Nevertheless, they displayed habituation and a relatively efficient circumnavigation, though, in both cases, different from those of sham rats. During test trials, hippocampal rats were characterized as being less accurate, making more errors than sham rats. Nevertheless, both groups increased their accuracy of first choices over trials. The qualitative analyses of test trial performance indicated that hippocampal rats were less accurate in terms of the initial error's deviation from the goal, and less efficient in terms of corrective behaviour than sham rats which used either the periphery or the spokes to attain economically the goal. Surprisingly, hippocampal rats were not limited to a taxon type orientation but learned to use the periphery, a tendency which developed over time. Seemingly, for sham rats, the problem-solving process took the form of updating information during transit. For hippocampal rats, the use of periphery reflected both an ability to discriminate its usefulness in reaching the goal via a taxis type behaviour, and some sparing of ability to generalize the closeness and the location of the goal. These results, especially the strategic correction patterns, are discussed in the light of Sutherland and Rudy's 'configurational association theory'.

  13. Modeling and simulation of wheeled polishing method for aspheric surface

    NASA Astrophysics Data System (ADS)

    Zong, Liang; Xie, Bin; Wang, Ansu

    2016-10-01

    This paper describes a new polishing tool for the polishing process of the aspheric lens: the wheeled polishing tool, equipping with an elastic polishing wheel which can automatically adapt to the surface shape of the lens, has been used to get high-precision surface based on the grinding action between the polishing wheel and the workpiece. In this paper, 3D model of polishing wheel structure is established by using the finite element analysis software. Distribution of the contact pressure between the polishing wheel and optical element is analyzed, and the contact pressure distribution function is deduced by using the least square method based on Hertz contact theory. The removal functions are deduced under different loading conditions based on Preston hypothesis. Finally, dwell time function is calculated. The simulation results show that the removal function and dwell time function are suitable for the wheeled polishing system, and thus establish a theoretical foundation for future research.

  14. Grinding Wheel Profile

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graphic dubbed by engineers as the 'Grinding Wheel Profile' is the detective's tool used by the Opportunity team to help them understand one of the processes that formed the interior of a rock called 'McKittrick.' Scientists are looking for clues as to how layers, grains and minerals helped create this rock, and the engineers who built the rock abrasion tool (RAT) wanted to ensure that their instrument's handiwork did not get confused with natural processes.

    In the original microscopic image underlaying the graphics, engineers and scientists noticed 'layers' or 'scratches' on the spherical object nicknamed 'blueberry' in the lower right part of the image. The designers of the rock abrasion tool noticed that the arc length and width of the scratches were similar to the shape and size of the rock abrasion tool's grinding wheel, which is made out of a pad of diamond teeth.

    The scrapes on the bottom right blueberry appear to be caused by the fact that the berry got dislodged slightly and its surface was scraped with the grinding pad. In this image, the largest yellow circle is the overall diameter of the hole ground by the rock abrasion tool and the largest yellow rectangular shape is the area of the grinding wheel bit. The smaller yellow semi-circle is the path that the center of the grinding tool follows. The orange arrow arcing around the solid yellow circle (center of grinding tool) indicates the direction that the grinding tool spins around its own center at 3,000 revolutions per minute. The tool simultaneously spins in an orbit around the center of the hole, indicated by the larger orange arrow to the left.

    The grinding tool is 22 millimeters (0.9 inches) in length and the actual grinding surface, which consists of the diamond pad, is 1.5 millimeters (0.06 inches) in length, indicated by the two smaller rectangles. You can see that the smaller bottom rectangle fits exactly the width of the scrape marks.

    The grooves on the blueberry are also the

  15. Grinding Wheel Profile

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This graphic dubbed by engineers as the 'Grinding Wheel Profile' is the detective's tool used by the Opportunity team to help them understand one of the processes that formed the interior of a rock called 'McKittrick.' Scientists are looking for clues as to how layers, grains and minerals helped create this rock, and the engineers who built the rock abrasion tool (RAT) wanted to ensure that their instrument's handiwork did not get confused with natural processes.

    In the original microscopic image underlaying the graphics, engineers and scientists noticed 'layers' or 'scratches' on the spherical object nicknamed 'blueberry' in the lower right part of the image. The designers of the rock abrasion tool noticed that the arc length and width of the scratches were similar to the shape and size of the rock abrasion tool's grinding wheel, which is made out of a pad of diamond teeth.

    The scrapes on the bottom right blueberry appear to be caused by the fact that the berry got dislodged slightly and its surface was scraped with the grinding pad. In this image, the largest yellow circle is the overall diameter of the hole ground by the rock abrasion tool and the largest yellow rectangular shape is the area of the grinding wheel bit. The smaller yellow semi-circle is the path that the center of the grinding tool follows. The orange arrow arcing around the solid yellow circle (center of grinding tool) indicates the direction that the grinding tool spins around its own center at 3,000 revolutions per minute. The tool simultaneously spins in an orbit around the center of the hole, indicated by the larger orange arrow to the left.

    The grinding tool is 22 millimeters (0.9 inches) in length and the actual grinding surface, which consists of the diamond pad, is 1.5 millimeters (0.06 inches) in length, indicated by the two smaller rectangles. You can see that the smaller bottom rectangle fits exactly the width of the scrape marks.

    The grooves on the blueberry are also the

  16. 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.

  17. Reinventing the Wheel

    ERIC Educational Resources Information Center

    Kim, Mihyeon; Bland, Lori C.; Chandler, Kimberley

    2009-01-01

    "The Wheel of Scientific Investigation and Reasoning" (Kramer 1987; Paul and Binker 1992) is a graphic representation of the scientific investigative process. The scientific process is depicted in a wheel rather than in a list because "the process of scientific inquiry can begin from any stage, and that stage may be revisited as often as the…

  18. 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)

  19. 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.

  20. 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.

  1. Linear-to-λ-Shape P-O-P Bond Transmutation in Polyphosphates with Infinite (PO3)∞ Chain.

    PubMed

    Wang, Ying; Li, Lin; Han, Shujuan; Lei, Bing-Hua; Abudoureheman, Maierhaba; Yang, Zhihua; Pan, Shilie

    2017-09-05

    A new metal polyphosphate, α-CsBa2(PO3)5, exhibiting the first example of a linear P-O-P bond angle in a one-dimensional (PO3)∞ chain has been reported. Interestingly, α → β phase transition occurs in CsBa2(PO3)5 along with the P-O-P bonds varying from linear to λ-shape, suggesting that α-CsBa2(PO3)5 with unfavorable linear P-O-P bonds is more stable at ambient temperature.

  2. 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.

  3. Reaction/Momentum Wheel

    NASA Technical Reports Server (NTRS)

    1997-01-01

    CTA Space Systems, Inc. has been licensed to sell commercially a reaction/momentum wheel originally developed for NASA's scientific satellites. NASA originally identified a need for the wheel in its Small Explorer program. The Submillimeter Wave Astronomy Satellite required extremely low jitter and a reaction/momentum wheel with a torque greater than any comparably sized commercially available wheel to keep the instrument pointed at celestial objects to a high degree of precision. After development, a market assessment by Research Triangle Institute was completed, showing commercial potential for the flywheel technology. A license was granted to CTA in the fall of 1996. The company currently uses the technology in its complete spacecraft fabrication services and has built over 10 reaction/momentum wheels for commercial, scientific, and military customers.

  4. The ubiquitous photonic wheel

    NASA Astrophysics Data System (ADS)

    Aiello, Andrea; Banzer, Peter

    2016-08-01

    A circularly polarized electromagnetic plane wave carries an electric field that rotates clockwise or counterclockwise around the propagation direction of the wave. According to the handedness of this rotation, its longitudinal spin angular momentum (AM) density is either parallel or antiparallel to the propagation of light. However, there are also light waves that are not simply plane and carry an electric field that rotates around an axis perpendicular to the propagation direction, thus yielding transverse spin AM density. Electric field configurations of this kind have been suggestively dubbed ‘photonic wheels’. It has been recently shown that photonic wheels are commonplace in optics as they occur in electromagnetic fields confined by waveguides, in strongly focused beams, in plasmonic and evanescent waves. In this work we establish a general theory of electromagnetic waves propagating along a well defined direction, and carrying transverse spin AM density. We show that depending on the shape of these waves, the spin density may be either perpendicular to the mean linear momentum (globally transverse spin) or to the linear momentum density (locally transverse spin). We find that the latter case generically occurs only for non-diffracting beams, such as the Bessel beams. Moreover, we introduce the concept of meridional Stokes parameters to operationally quantify the transverse spin density. To illustrate our theory, we apply it to the exemplary cases of Bessel beams and evanescent waves. These results open a new and accessible route to the understanding, generation and manipulation of optical beams with transverse spin AM density.

  5. Surface modification with multiphilic ligands at detectable well defined active positions of nano-object of giant wheel shaped molybdenum blue showing third-order nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    Zhang, Lijuan; Li, Yuhao; Zhou, Yunshan

    2010-04-01

    The reaction of an aqueous solution of sodium molybdate with L-tyrosine in the presence of reducing agent results in the formation of a new compound of the formula of Na 8Co 3[Mo VI126 Mo V28O 462H 14(H 2O) 46(HOC 6H 4CH 2CH( NH3+)COO -) 12]·ca. 200H 2O. The compound contains nanosized ring-shaped clusters with tyrosine ligands possessing different types of functional groups (one -CO 2, one -NH3+ and one -ArOH) coordinated through the carboxylate groups at the active sites of the inner cavity. Importantly, the result demonstrates that not only active sites/areas of the cluster surface under a specified condition can be directly monitored and detected but also novel type surfaces within the cavity of a nano-structured ring-shaped cluster can be generated simultaneously. The nonlinear optical properties of the new cluster are studied using the well-known Z-scan technique at a wavelength of 532 nm with laser pulse duration of 18 ps. The results show that the new cluster exhibits interesting self-focusing nonlinear optical response with the real and imaginary parts of the third-order nonlinear optical susceptibility χ(3) being 1.069 × 10 -13(esu) and 2.529 × 10 -15(esu), respectively, which may find application in material science.

  6. Burst shaping in a fiber-amplifier chain seeded by a gain-switched laser diode.

    PubMed

    Petelin, Jaka; Podobnik, Boštjan; Petkovšek, Rok

    2015-05-20

    A low-power source, such as a gain-switched laser diode, usually requires several amplification stages to reach sufficient power levels. When operating in burst mode, a correct input burst shape must be determined in order to compensate for gain saturation of all amplifier stages. In this paper we report on closed-form equations that enable saturation compensation in multiamplifier setups, which eliminates the need for an adaptive feedback loop. The theoretical model is then evaluated in an experimental setup.

  7. Molecular-shape selective high-performance liquid chromatography: stabilization effect of polymer main chain by alternating copolymerization.

    PubMed

    Mallik, Abul K; Qiu, Hongdeng; Sawada, Tsuyoshi; Takafuji, Makoto; Ihara, Hirotaka

    2012-04-06

    This work aims to clarify that stabilization or increased rigidity of polymer main chains as an organic stationary phase can lead the selectivity enhancement in high-performance liquid chromatography (HPLC). For this purpose, the alternating copolymer of octadecyl acrylate (ODA) with a cyclic monomer (N-octadecylmaleimide, OMI) as a rigid segment was synthesized and compared with the ODA homopolymer. Both of the polymer-grafted silicas (Sil-poly(ODA-alt-OMI) and Sil-poly(ODA), respectively) were prepared by radical polymerization on 3-mercaptopropyltrimethoxysilane-modified silica. The characterizations were carried out by elemental analyses, diffuse reflectance infrared Fourier transform (DRIFT), and solid-state (13)C cross-polarization magic angle spinning nuclear magnetic resonance (CP-MAS-NMR) spectroscopies. Chromatographic behaviors were evaluated by the retention studies of shape-constrained isomers of polycyclic aromatic hydrocarbons (PAHs), isomers of tocopherol and carotenoids. Higher molecular-linearity selectivity toward PAHs was obtained on Sil-poy(ODA-alt-OMI) regardless of temperature changes but at temperature below 40 °C, Sil-poly(ODA) showed better planarity selectivity than that of Sil-poy(ODA-alt-OMI). As a result, the higher separation ability toward tocopherols and carotenoids was obtained on Sil-poy(ODA-alt-OMI). These results indicate that the stabilization in the polymer main chain by alternating copolymerization and the stabilization in the side chains by a disordered-to-ordered phase transition were effective to enhance the molecular-shape selectivity. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. 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.

  9. 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.

  10. Science Can Be Wheel Fun.

    ERIC Educational Resources Information Center

    Leyden, Michael B.

    1980-01-01

    Describes how teachers can use wheels of tricycles, bicycles, and trains to stimulate children with mathematics, relative position, and engineering concepts. Techniques are offered for measuring circumference of a bicycle wheel, gear ratios, and pedal wheel circumferences. Comparative data are given for various sized wheels. (Author/SA)

  11. Shape-Selectivity with Liquid Crystal and Side-Chain Liquid Crystalline Polymer SAW Sensor Interfaces

    SciTech Connect

    FRYE-MASON,GREGORY CHARLES; OBORNY,MICHAEL C.; PUGH,COLEEN; RICCO,ANTONIO; THOMAS,ROSS C.; ZELLERS,EDWARD T.; ZHANG,GUO-ZHENG

    1999-09-23

    A liquid crystal (LC) and a side-chain liquid crystalline polymer (SCLCP) were tested as surface acoustic wave (SAW) vapor sensor coatings for discriminating between pairs of isomeric organic vapors. Both exhibit room temperature smectic mesophases. Temperature, electric-field, and pretreatment with self-assembled monolayers comprising either a methyl-terminated or carboxylic acid-terminated alkane thiol anchored to a gold layer in the delay path of the sensor were explored as means of affecting the alignment and selectivity of the LC and SCLCP films. Results for the LC were mixed, while those for the SCLCP showed a consistent preference for the more rod-like isomer of each isomer pair examined.

  12. 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.

  13. 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.

  14. NICMOS Filter Wheel Test

    NASA Astrophysics Data System (ADS)

    Wheeler, Thomas

    2009-07-01

    This is an engineering test {described in SMOV4 Activity Description NICMOS-04} to verify the aliveness, functionality, operability, and electro-mechanical calibration of the NICMOS filter wheel motors and assembly after NCS restart in SMOV4. 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 operating temperature.Addition of visits G0 - G9 {9/9/09}: Ten visits copied from proposal 11868 {visits 20, 30, ..., 90, A0, B0}. Each visit moves two filter positions, takes lamp ON/OFF exposures and then moves back to the blank position. Visits G0, G1 and G2 will leave the filter wheels disabled. The remaining visits will leave the filter wheels enabled. There are sufficient in between times to allow for data download and analysis. In the case of problem is encountered, the filter wheels will be disabled through a real time command. The in between times are all set to 22-50 hours. It is preferable to have as short as possible in between time.

  15. Object-adapted trapping and shape-tracking to probe a bacterial protein chain motor

    NASA Astrophysics Data System (ADS)

    Roth, Julian; Koch, Matthias; Rohrbach, Alexander

    2015-03-01

    The helical bacterium Spiroplasma is a motile plant and anthropod pathogen which swims by propagating pairs of kinks along its cell body. As a well suited model system for bacterial locomotion, understanding the cell's molecular motor is of vital interest also regarding the combat of bacterial diseases. The extensive deformations related to these kinks are caused by a contractile cytoskeletal protein ribbon representing a linear motor in contrast to common rotary motors as, e.g., flagella. We present new insights into the working of this motor through experiments with object-adapted optical traps and shape-tracking techniques. We use the given laser irradiation from the optical trap to hinder bacterial energy (ATP) production through the production of O2 radicals. The results are compared with experiments performed under the influence of an O2-Scavenger and ATP inhibitors, respectively. Our results show clear dependences of the kinking properties on the ATP concentration inside the bacterium. The experiments are supported by a theoretical model which we developed to describe the switching of the ribbon's protein subunits.

  16. Two-dimensional oligo(phenylene-ethynylene-butadiynylene)s: all-covalent nanoscale spoked wheels.

    PubMed

    Lei, Shengbin; Ver Heyen, An; De Feyter, Steven; Surin, Mathieu; Lazzaroni, Roberto; Rosenfeldt, Sabine; Ballauff, Matthias; Lindner, Peter; Mössinger, Dennis; Höger, Sigurd

    2009-03-02

    Round and round: Covalently bound spokes induce an efficient template-directed cyclization towards a rigid molecular wheel (see figure) and afford dramatically increased shape-persistence properties compared with non-strutted macrocycles.The synthesis and characterization of a shape-persistent two-dimensional (2D) organic compound is described in detail. In a rational modular synthesis of a dodecaacetylene precursor and its subsequent template-aided cyclization, we obtained a molecularly defined, stable, C(6)-symmetric, rigid, spoked wheel. Peripheral tert-butyl groups and alkyl chains attached to the plane of the molecule provide sufficient solubility, so that the 2D oligomer can be fully characterized by MALDI-MS, GPC, and (1)H NMR, UV/Vis absorption, and fluorescence spectroscopy. Molecular mechanics and dynamics simulations indicate that the most stable conformer of the molecule in vacuum is a shallow boat conformation with a small dihedral angle. Comparisons with the precursor as well as a ring-only structure clearly reveal the high rigidity of the title compound. Small-angle neutron scattering (SANS) experiments in [D(8)]THF and CDCl(3) affirm the rigid backbone structure in solution, that is, a radius of about 2.7 nm and a thickness of about 0.22 nm. STM investigations illustrate that the wheel molecules adsorb with their molecular plane parallel to the surface and can form hexagonal crystalline domains (unit cell parameters are a=b=6.0+/-0.2 nm and theta=60+/-2 degrees ), with the tert-butyl groups on the apexes staggered. Such staggering induces chirality in the organized domains. AFM investigations demonstrate that the wheel molecules inside overlayers organize in the same way as in the layer directly in contact with the surface. This indicates an epitaxial growth characteristic of the film.

  17. Wheel Electrometer System

    NASA Technical Reports Server (NTRS)

    Calle, Carlos I.; Buehler, Martin G.; Mantovani, James G.; Buhler, Charles; Nomicki, Andrew

    2005-01-01

    Two documents describe a prototype system of electrometers for measuring electrostatic fields and electrostatic responses of soils on Mars and the Moon. The electrodes of this electrometer are embedded in a wheel of an exploratory robotic vehicle, utilizing the wheel motion to bring the electrodes into proximity or contact with the soil. Each electrode resides in one of two types of sensor modules: electric-field (ELF) or triboelectric (TRIBO). In either type, what is measured is simply the electric charge induced on the electrode by exposure to the external distribution of electrostatic charge. In an ELF module, the electrode is bare and recessed radially from the wheel surface. The ELF sensor provides a measure of the charge on a small patch of undisturbed soil as the wheel rolls forward. In a TRIBO module, the electrode is only slightly recessed and covered with a polymeric insulator flush with the wheel surface. Through contact electrification, the insulator exchanges charge with the soil. There are five TRIBO sensors, each containing an insulator made of a different polymer. The charge data gathered by the five TRIBO sensors can be used to determine how the soil fits into a triboelectric series.

  18. 14. MACHINERY DETAILS: CENTER WHEEL FRAME AND AXEL, JACK WHEEL ...

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

    14. MACHINERY DETAILS: CENTER WHEEL FRAME AND AXEL, JACK WHEEL FRAME, JACK NUT HOUSING, JACK NUT, ETC. - Niantic River Swing Bridge, Spanning Niantic River between East Lyme & Waterford, Old Lyme, New London County, CT

  19. Interior of wheel pit looking northwest; detail of pelton wheel ...

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

    Interior of wheel pit looking northwest; detail of pelton wheel with backshot nozzle and deflectors (above), and undershot nozzle and deflectors (below). - Nooksack Falls Hydroelectric Plant, Route 542, Glacier, Whatcom County, WA

  20. Magnetically suspended reaction wheels

    NASA Technical Reports Server (NTRS)

    Sabnis, A. V.; Stocking, G. L.; Dendy, J. B.

    1975-01-01

    Magnetic suspensions offer several advantages over conventional bearings, arising because of the contactless nature of the load support. In application to spacecraft reaction wheels, the advantages are low drag torque, wearfree, unlubricated, vacuum-compatible operation, and unlimited life. By the provision of redundancy in the control electronics, single-point failures are eliminated. The rational for selection of a passive radial, active axial, dc magnetic suspension is presented, and the relative merits of 3-loop and single-loop magnetic suspensions are discussed. The design of a .678 N-m-sec (.5 ft-lb-sec) reaction wheel using the single loop magnetic suspension was developed; the design compares favorably with current ball bearing wheels in terms of weight and power.

  1. Testing Sequences of Wheel Turns

    NASA Image and Video Library

    2009-07-21

    Mars Exploration Rover team members on July 21, 2009, tested how altering the order in which individual wheels turn for steering affects how those turns dig the wheels deeper into soft soil. From left: Alfonso Herrera, Vandana Verma, Bruce Banerdt.

  2. Wheel Diameter and Speedometer Reading

    ERIC Educational Resources Information Center

    Murray, Clifton

    2010-01-01

    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…

  3. Wheel Diameter and Speedometer Reading

    ERIC Educational Resources Information Center

    Murray, Clifton

    2010-01-01

    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…

  4. Drive Diagnostic Filter Wheel Control

    SciTech Connect

    Uhlich, D.

    2007-07-17

    DrD Filter Wheel Control is National Instrument's Labview software that drives a Drive Diagnostic filter wheel. The software can drive the filter wheel between each end limit, detect the positive and negative limit and each home position and post the stepper motot values to an Excel spreadsheet. The software can also be used to cycle the assembly between the end limits.

  5. 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)

  6. 3-D Color Wheels

    ERIC Educational Resources Information Center

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  7. Slit Wheel Repeatability

    NASA Astrophysics Data System (ADS)

    DiFelice, Audrey

    2013-10-01

    Test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}. This is a clone of Cycle 20 Program 13140.

  8. Slit Wheel Repeatability

    NASA Astrophysics Data System (ADS)

    Long, Chris

    2011-10-01

    Test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}. This is a clone of Cycle 18 Program 12410.

  9. Slit Wheel Repeatability

    NASA Astrophysics Data System (ADS)

    DiFelice, Audrey

    2012-10-01

    Test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}. This is a clone of Cycle 19 Program 12771.

  10. 3-D Color Wheels

    ERIC Educational Resources Information Center

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  11. 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.)

  12. 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.

  13. 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.)

  14. Aircraft Wheel Life Assessment

    DTIC Science & Technology

    1993-07-01

    responsible for a significant amount of aircraft dam - age. Many such wheel failures have been catastrophic, resulting in a sudden loss of tire inflation...Fatigue Crack Growth," Fatigue and Fracture in Engineering Materials and Structures, Vol. 10, 419-428, 1987. Cox, B. N., Pardee , W., and Morris, W. L

  15. Atomic Ferris wheel beams

    NASA Astrophysics Data System (ADS)

    Lembessis, Vasileios E.

    2017-07-01

    We study the generation of atom vortex beams in the case where a Bose-Einstein condensate, released from a trap and moving in free space, is diffracted from a properly tailored light mask with a spiral transverse profile. We show how such a diffraction scheme could lead to the production of an atomic Ferris wheel beam.

  16. Odd-even effect of transport through a chain of Majorana bound states in a T-shaped junction

    NASA Astrophysics Data System (ADS)

    Gong, W. J.; Wu, B. H.; Zhang, S. F.; Zheng, Y. S.

    2014-05-01

    We investigate the transport characteristics of a chain of Majorana bound states (MBSs) in a T-shaped junction, where two normal leads are coupled to the same terminate MBS. We find the apparent odd-even effect in the transport process. Namely, when the MBS number is odd, the conductance spectrum exhibits a peak in the zero-bias limit. Besides, the shot noise Fano factor in the zero-bias limit (F_0) and the conductance maximum (G_{\\textit{max}}) are related by equation F_0=1-{1\\over2}T_{\\textit{max}} with G={e^2\\over h}T . Otherwise, in the case of even-numbered MBSs, at the zero-bias limit, the conductance encounters its zero value, and the relation between F0 and G_{\\textit{max}} changes as F_0=1+{1\\over2}T_{\\textit{max}} . Further investigation shows that these two kinds of relations are caused by the different interplay mechanisms between the crossed Andreev reflection and the local Andreev reflection. In addition, it is observed that the fluctuation of the inter-MBS couplings contributes little to the transport results. We ascertain that these results are helpful for understanding the MBS signature in transport spectra.

  17. Testing Spirit on Five Wheels

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This picture shows a model of the Mars Exploration Rover Spirit being tested for performance on five wheels at NASA's Jet Propulsion Laboratory. Spirit's right front wheel, now operating at six times its design life, has been showing signs of age, so rover planners devised a creative approach to keep the rover moving. They will drive Spirit backwards on five wheels, engaging the sixth wheel only sparingly to ensure its availability for tougher terrain. Tests performed at JPL allowed the rover planners to come up with this roundabout solution, and to develop commands that will help the five-wheeled rover steer.

  18. 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.

  19. Differential roles of Rho-kinase and myosin light chain kinase in regulating shape, adhesion, and migration of HT1080 fibrosarcoma cells.

    PubMed

    Niggli, Verena; Schmid, Manuela; Nievergelt, Alexandra

    2006-05-05

    We present evidence for differential roles of Rho-kinase and myosin light chain kinase (MLCK) in regulating shape, adhesion, migration, and chemotaxis of human fibrosarcoma HT1080 cells on laminin-coated surfaces. Pharmacological inhibition of Rho-kinase by Y-27632 or inhibition of MLCK by W-7 or ML-7 resulted in significant attenuation of constitutive myosin light chain phosphorylation. Rho-kinase inhibition resulted in sickle-shaped cells featuring long, thin F-actin-rich protrusions. These cells adhered more strongly to laminin and migrated faster. Inhibition of MLCK in contrast resulted in spherical cells and marked impairment of adhesion and migration. Inhibition of myosin II activation with blebbistatin resulted in a morphology similar to that induced by Y-27632 and enhanced migration and adhesion. Cells treated first with blebbistatin and then with ML-7 also rounded up, suggesting that effects of MLCK inhibition on HT1080 cell shape and motility are independent of inhibition of myosin activity.

  20. Railway ground vibrations induced by wheel and rail singular defects

    NASA Astrophysics Data System (ADS)

    Kouroussis, Georges; Connolly, David P.; Alexandrou, Georgios; Vogiatzis, Konstantinos

    2015-10-01

    Railway local irregularities are a growing source of ground-borne vibration and can cause negative environmental impacts, particularly in urban areas. Therefore, this paper analyses the effect of railway track singular defects (discontinuities) on ground vibration generation and propagation. A vehicle/track/soil numerical railway model is presented, capable of accurately predicting vibration levels. The prediction model is composed of a multibody vehicle model, a flexible track model and a finite/infinite element soil model. Firstly, analysis is undertaken to assess the ability of wheel/rail contact models to accurately simulate the force generation at the wheel/rail contact, in the presence of a singular defect. It is found that, although linear contact models are sufficient for modelling ground vibration on smooth tracks, when singular defects are present higher accuracy wheel/rail models are required. Furthermore, it is found that the variation in wheel/rail force during the singular defect contact depends on the track flexibility, and thus requires a fully coupled vehicle/track/foundation model. Next, a parametric study of ground vibrations generated by singular rail and wheel defects is undertaken. Six shapes of discontinuity are modelled, representing various defect types such as transition zones, switches, crossings, rail joints and wheel flats. The vehicle is modelled as an AM96 train set and it is found that ground vibration levels are highly sensitive to defect height, length and shape.

  1. Scaling Relations for Wheeled Locomotion in Granular Media

    NASA Astrophysics Data System (ADS)

    Slonaker, James; Kamrin, Ken

    Vehicular wheel design for use on granular material has not currently been perfected. Resistive Force Theory (RFT) is a reduced-order empirical model for granular drag, which shows promise to help simulate and understand locomotion processes to design more efficient wheels. Here we explore the fundamental scaling relations derived from RFT and their experimental validation. Similar to the non-dimensional scaling relations in fluid mechanics, the relative simplicity of RFT asserts that only one material parameter, the ''grain-structure coefficient'', is required, which reduces the complexity of the non-dimensional groups implied by the system. Therefore, wheels with differing input design parameters like size, mass, shape and even gravity, can be tested and their performance related to each other in predictable ways. We experimentally confirmed these relations by testing with 3D printed wheel geometries in a controlled sand bed.

  2. CFD simulations to optimize the blade design of water wheels

    NASA Astrophysics Data System (ADS)

    Quaranta, Emanuele; Revelli, Roberto

    2017-05-01

    At low head sites and at low discharges, water wheels can be considered among the most convenient hydropower converters to install. The aim of this work is to improve the performance of an existing breastshot water wheel by changing the blade shape using computational fluid dynamic (CFD) simulations. Three optimal profiles are investigated: the profile of the existing blades, a circular profile and an elliptical profile. The results are validated by performing experimental tests on the wheel with the existing profile. The numerical results show that the efficiency of breastshot wheels is affected by the blade profile. The average increase in efficiency using the new circular profile is about 4 % with respect to the profile of the existing blades.

  3. 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.

  4. Wheel loader round up

    SciTech Connect

    Fiscor, S.

    2007-02-15

    Operator comfort and serviceability remain important features of front-end loaders or wheel loaders. The article reports on features of the latest large loaders from three companies: Caterpillar (the 992G and 994F), Komatsu (the WA800-3, WA900-3 and WA1200-3), and Le Tourneau (the L-950, L-1350, L-1850 and L-2350). 1 tab., 4 photos.

  5. 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)

  6. 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.

  7. Experiments with Electrodynamic Wheels

    NASA Astrophysics Data System (ADS)

    Gaul, Nathan; Corey, Daniel; Cordrey, Vincent; Majewski, Walerian

    2015-04-01

    Our experiments were involving inductive magnetic levitation. A Halbach array is a system in which a series of magnets is arranged in a manner such that the magnetic field is cancelled on one side of the array while strengthening the field on the other. We constructed two circular Halbach wheels, making the strong magnetic field on the outer rim of the ring. Such system is usually dubbed as an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We demonstrated that these interactions produce both drag and lift forces on the EDW which can theoretically be used for lift and propulsion of the EDW. The focus of our experiments is determining how to maximize the lift-to-drag ratio by the proper choice of the induction element. We will also describe our experiments with a rotating circular Halbach array having the strong magnetic field of about 1 T on the flat side of the ring, and acting as a hovercraft.

  8. 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

  9. 49 CFR 230.114 - Wheel centers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel... provided in paragraph (b)(4) of this section; or (4) Driving or trailing wheel center with three adjacent... 49 Transportation 4 2011-10-01 2011-10-01 false Wheel centers. 230.114 Section 230.114...

  10. 49 CFR 230.114 - Wheel centers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel... provided in paragraph (b)(4) of this section; or (4) Driving or trailing wheel center with three adjacent... 49 Transportation 4 2010-10-01 2010-10-01 false Wheel centers. 230.114 Section 230.114...

  11. 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.

  12. 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.

  13. 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.

  14. Tracked Vehicle Road Wheel Puller

    DTIC Science & Technology

    2009-02-01

    threaded rod can be rotated with respect to its bracket member to be physically moved against the blower wheel, which separates from its associated...64. The cylinder leg 64 includes an arcuate and recessed top inner surface 66, upon which is seatingly engaged a first (or outer) cylinder...surface (as referenced at 140) associated with the inner road wheel component 122. In this manner, the wheel-puller assembly is activated to

  15. 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.

  16. 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)

    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.

  17. 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.

  18. Magnetically suspended reaction wheel assembly

    NASA Technical Reports Server (NTRS)

    Stocking, G.

    1984-01-01

    The magnetically suspended reaction wheel assembly (MSRWA) is the product of a development effort funded by the Air Force Materials Laboratory (AFML) at Wright Patterson AFB. The specific objective of the project was to establish the manufacturing processes for samarium cobalt magnets and demonstrate their use in a space application. The development was successful on both counts. The application portion of the program, which involves the magnetically suspended reaction wheel assembly, is emphasized. The requirements for the reaction wheel were based on the bias wheel requirements of the DSP satellite. The tasks included the design, fabrication, and test of the unit to the DSP program qualification requirements.

  19. Self-Damping Sprung Wheel

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1993-01-01

    Self-damping sprung wheel provides shock-absorbing suspension for wheelchair, reducing user's discomfort when traversing rough terrain or obstacles. Pair of self-damping sprung wheels installed in place of conventional large rear wheels of standard wheelchair, which user operates in conventional manner. Rim deflects in vicinity of contact with ground or floor. Includes inner and outer hoops bending when obstacle encountered. Shear deformation of elastomeric hoop between them absorbs energy. Thus, three hoops act together as damping spring. Alternative version of wheel designed for bicycle.

  20. Self-Damping Sprung Wheel

    NASA Technical Reports Server (NTRS)

    Weddendorf, Bruce

    1993-01-01

    Self-damping sprung wheel provides shock-absorbing suspension for wheelchair, reducing user's discomfort when traversing rough terrain or obstacles. Pair of self-damping sprung wheels installed in place of conventional large rear wheels of standard wheelchair, which user operates in conventional manner. Rim deflects in vicinity of contact with ground or floor. Includes inner and outer hoops bending when obstacle encountered. Shear deformation of elastomeric hoop between them absorbs energy. Thus, three hoops act together as damping spring. Alternative version of wheel designed for bicycle.

  1. 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.

  2. Chiral hexanuclear ferric wheels.

    PubMed

    Fielden, John; Speldrich, Manfred; Besson, Claire; Kögerler, Paul

    2012-03-05

    The homochiral iron(III) wheels [Fe(6){(S)-pedea}(6)Cl(6)] and [Fe(6){(R)-pedea)}(6)Cl(6)] [(R)- and (S)-2; pedea = phenylethylaminodiethoxide] exhibit high optical activities and antiferromagnetic exchange. These homochiral products react with each other, producing the centrosymmetric, crystallographically characterized [Fe(6){(S)-pedea}(3){(R)-pedea}(3)Cl(6)] diastereomer [(RSRSRS)-2]. (1)H NMR and UV-vis studies indicate that exchange processes are slow in both homo- and heterochiral systems but that, upon combination, the reaction between (R)- and (S)-2 occurs quickly.

  3. 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.

  4. 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.

  5. 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.

  6. 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)

  7. Cohesions, friction angles, and other physical properties of Martian regolith from Mars Exploration Rover wheel trenches and wheel scuffs

    NASA Astrophysics Data System (ADS)

    Sullivan, R.; Anderson, R.; Biesiadecki, J.; Bond, T.; Stewart, H.

    2011-02-01

    The Mars Exploration Rovers Spirit and Opportunity investigated the physical properties of Martian regolith in 7 wheel trenches and 20 wheel scuffs distributed along traverses at Gusev crater and Meridiani Planum. Specialized wheel-trenching sequences allowed analysis of wheel motor and suspension telemetry to determine regolith friction angle $\\phi$ and cohesion c at trench sites. Friction angles were 30°-37°, and cohesions were 0-2 kPa. Simpler wheel-scuff maneuvers were analyzed for cohesion by assuming the range of $\\phi$ determined from trenches; cohesions in wheel-scuffed regoliths were from 0 to 11 kPa. Regolith $\\phi$ and c can be related to regolith origins. Grain sorting, compaction, shape, size, and angularity influence $\\phi$. Impact cratering and aeolian processes have affected grain angularity and sorting of Martian regolith at both Mars Exploration Rover (MER) landing sites and contend in opposing ways to determine grain characteristics in the regolith. Friction angles are consistent with dry, rigid, nonplaty grains with particle size frequencies dominated by very fine sand (as seen by the Microscopic Imager or MI) with at least some grain rounding (unresolved by MI), reflecting physical weathering from aeolian saltation. Friction angle results from MER trenches therefore indicate that regolith states are between fully mature aeolian materials and impact debris. MI and color Pancam views show trench tailings and trench floors are redder, brighter, and have more intermixed extremely fine (unresolved) grains than regolith closer to the surface disturbed and exposed only by rolling tracks.

  8. Innovative stair climber using associated wheels

    NASA Astrophysics Data System (ADS)

    Modak, Girish Sudhir; Bhoomkar, Manmohan Manikrao

    2016-09-01

    The study proposes an innovative and completely new but low-cost configuration of a platform that can easily climb stairs. This platform serves the purpose of a chassis. Different versions, such as staircase-climbing wheelchair or staircase-climbing trolley for material transferring, can be derived depending on the structure built on the platform. The driving wheels have a shape that completely matches with the profile of the steps. Complex components are eliminated. Thus, this platform is conveniently applicable in the configurations useful for climbing staircases.

  9. Synthesis and arm dissociation in molecular stars with a spoked wheel core and bottlebrush arms.

    PubMed

    Burdyńska, Joanna; Li, Yuanchao; Aggarwal, Anant Vikas; Höger, Sigurd; Sheiko, Sergei S; Matyjaszewski, Krzysztof

    2014-09-10

    Unique star-like polymeric architectures composed of bottlebrush arms and a molecular spoked wheel (MSW) core were prepared by atom transfer radical polymerization (ATRP). A hexahydroxy-functionalized MSW (MSW(6-OH)) was synthesized and converted into a six-fold ATRP initiator (MSW(6-Br)). Linear chain arms were grafted from MSW(6-Br) and subsequently functionalized with ATRP moieties to form six-arm macroinitiators. Grafting of side chains from the macroinitiators yielded four different star-shaped bottlebrushes with varying lengths of arms and side chains, i.e., (450-g-20)6, (450-g-40)6, (300-g-60)6, and (300-g-150)6. Gel permeation chromatography analysis and molecular imaging by atomic force microscopy confirmed the formation of well-defined macromolecules with narrow molecular weight distributions. Upon adsorption to an aqueous substrate, the bottlebrush arms underwent prompt dissociation from the MSW core, followed by scission of covalent bonds in the bottlebrush backbones. The preferential cleavage of the arms is attributed to strong steric repulsion between bottlebrushes at the MSW branching center. Star-shaped macroinitiators may undergo aggregation which can be prevented by sonication.

  10. 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.

  11. Synthesis and STM imaging of symmetric and dissymmetric ethynyl-bridged dimers of boron-subphthalocyanine bowl-shaped nanowheels.

    PubMed

    Jacquot de Rouville, Henri-Pierre; Garbage, Romain; Ample, Francisco; Nickel, Anja; Meyer, Joerg; Moresco, Francesca; Joachim, Christian; Rapenne, Gwénaël

    2012-07-16

    The future's wheel: A new class of wheels, based on subphthalocyanine fragments, for future incorporation in functional nanovehicles is reported (see figure). The syntheses of a symmetric wheel, a nitrogen-tagged wheel, and their ethynyl-bridged homodimers are presented. Theoretical calculations and STM imaging demonstrate the advantage of a bowl-shaped structure and the efficiency of the tag for STM imaging.

  12. alpha-Aminoalkylphosphonates as a tool in experimental optimisation of P1 side chain shape of potential inhibitors in S1 pocket of leucine- and neutral aminopeptidases.

    PubMed

    Drag, Marcin; Grembecka, Jolanta; Pawełczak, Małgorzata; Kafarski, Paweł

    2005-08-01

    The synthesis and biological activity studies of the series of structurally different alpha-aminoalkylphosphonates were performed in order to optimise the shape of the side chain of the potential inhibitors in S1 pocket of leucine aminopeptidase [E.C.3.4.11.1]. Analysis of a series of compounds with aromatic, aliphatic and alicyclic P1 side chains enabled to find out the structural features, optimal for that fragment of inhibitors of LAP. The most active among all investigated compounds were the phosphonic analogues of homo-tyrosine (K(i)=120 nM) and homo-phenylalanine (K(i)=140 nM), which even as racemic mixtures were better inhibitors in comparison with the best till now-phosphonic analogue of l-leucine (230 nM). Additional comparison of the inhibitory activity obtained for aminopeptidase N (APN, E.C.3.4.11.2) give insight into structural preferences of both enzymes.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels

    NASA Astrophysics Data System (ADS)

    Reilly, C.; Duan, J.; Yao, L.; Maijer, D. M.; Cockcroft, S. L.

    2013-09-01

    Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels are in a select group of cast components that have strict specifications for both mechanical and aesthetic characteristics due to their important structural requirements and their visibility on a vehicle. The modern aluminum alloy automotive wheel continues to experience tightened tolerances relating to defects to improve mechanical performance and/or the physical appearance. Automotive aluminum alloy wheels are assessed against three main criteria: wheel cosmetics, mechanical performance, and air tightness. Failure to achieve the required standards in any one of these categories will lead to the wheel either requiring costly repair or being rejected and remelted. Manufacturers are becoming more reliant on computational process modeling as a design tool for the wheel casting process. This article discusses and details examples of the use of computational process modeling as a predictive tool to optimize the casting process from the standpoint of defect minimization with the emphasis on those defects that lead to failure of aluminum automotive wheels, namely, macroporosity, microporosity, and oxide films. The current state of applied computational process modeling and its limitations with regard to wheel casting are discussed.

  18. The CodY-dependent clhAB2 operon is involved in cell shape, chaining and autolysis in Bacillus cereus ATCC 14579.

    PubMed

    Huillet, Eugénie; Bridoux, Ludovic; Wanapaisan, Pagakrong; Rejasse, Agnès; Peng, Qi; Panbangred, Watanalai; Lereclus, Didier

    2017-01-01

    The Gram-positive pathogen Bacillus cereus is able to grow in chains of rod-shaped cells, but the regulation of chaining remains largely unknown. Here, we observe that glucose-grown cells of B. cereus ATCC 14579 form longer chains than those grown in the absence of glucose during the late exponential and transition growth phases, and identify that the clhAB2 operon is required for this chain lengthening phenotype. The clhAB2 operon is specific to the B. cereus group (i.e., B. thuringiensis, B. anthracis and B. cereus) and encodes two membrane proteins of unknown function, which are homologous to the Staphylococcus aureus CidA and CidB proteins involved in cell death control within glucose-grown cells. A deletion mutant (ΔclhAB2) was constructed and our quantitative image analyses show that ΔclhAB2 cells formed abnormal short chains regardless of the presence of glucose. We also found that glucose-grown cells of ΔclhAB2 were significantly wider than wild-type cells (1.47 μm ±CI95% 0.04 vs 1.19 μm ±CI95% 0.03, respectively), suggesting an alteration of the bacterial cell wall. Remarkably, ΔclhAB2 cells showed accelerated autolysis under autolysis-inducing conditions, compared to wild-type cells. Overall, our data suggest that the B. cereus clhAB2 operon modulates peptidoglycan hydrolase activity, which is required for proper cell shape and chain length during cell growth, and down-regulates autolysin activity. Lastly, we studied the transcription of clhAB2 using a lacZ transcriptional reporter in wild-type, ccpA and codY deletion-mutant strains. We found that the global transcriptional regulatory protein CodY is required for the basal level of clhAB2 expression under all conditions tested, including the transition growth phase while CcpA, the major global carbon regulator, is needed for the high-level expression of clhAB2 in glucose-grown cells.

  19. Wind wheel electric power generator

    SciTech Connect

    Kaufman, J.W.

    1980-03-04

    Wind wheel electric power generator apparatus is disclosed as including a housing rotatably mounted upon a vertically disposed support column. Primary and auxiliary funnel-type, venturi ducts are fixedly mounted upon the housing for capturing wind currents and for conducting the same to a bladed wheel adapted to be operatively connected with 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.

  20. 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.

  1. 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.

  2. Parametric study of wheel transitions at railway crossings

    NASA Astrophysics Data System (ADS)

    Wan, C.; Markine, V. L.

    2015-12-01

    Vehicle-track interaction at railway crossings is complex due to the discontinuity of the crossings. In this study, the effect of the local crossing geometry, the track alignment, and the wheel profiles on the wheel transition behaviour is investigated using the multi-body system software package VI-Rail. The transition behaviour is evaluated based on the location of the transition point along the crossing (and the location of impact), the contact pressure and the energy dissipation during the wheel-rail contact. A detailed parametric study of the crossing geometry has been performed, through which the most effective parameters for defining the crossing geometry are identified. These parameters are the cross-sectional shape of the nose rail, which can be tuned by one variable, and the vertical distance between the top of the wing rail and the nose rail. Additionally, a parametric study on the interaction influence of the crossing geometry, the track alignment and the wheel profile is performed using the design of experiments method with a two-level full factorial design. The longitudinal height profile of the crossing and the wheel profile are the most significant factors.

  3. Four-wheel drive system

    SciTech Connect

    Asano, H.

    1989-04-18

    A four-wheel drive system is described having a torque transmission device between front wheels and rear wheels of a vehicle, the torque transmission device comprising: a stationary casing secured to a frame of the vehicle; an oil pump positioned in the casing and mechanically connected to be actuated by the relative rotations of a first rotating shaft connected to the front wheels and a second rotating shaft connected to the rear wheels for discharging pressure oil; a hydraulic clutch mounted in the casing; an electromagnetic throttle valve fluidically connected to the discharge passage and having a solenoid for varying a throttle opening thereof in response to an electric current applied to the solenoid so as to control the pressure of oil admitted in the cylinder chamber; a speed sensor for detecting a traveling speed of the vehicle; a steering angle sensor for detecting a rotational angle of a steering wheel of the vehicle; and control means electrically connected to the speed sensor, the steering angle sensor and the solenoid of the electromagnetic throttle valve for applying to the solenoid an electric current depending on signals from the speed sensor and the steering angle sensor so as to vary the throttle opening of the electromagnetic throttle valve wherein the oil pump and the hydraulic clutch are mounted on facing end portions of the first and second rotating shafts, respectively, in tandem fashion.

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

    NASA Technical Reports Server (NTRS)

    Rizvi, Farheen

    2013-01-01

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

  5. Photoanode based on chain-shaped anatase TiO2 nanorods for high-efficiency dye-sensitized solar cells.

    PubMed

    Rui, Yichuan; Li, Yaogang; Wang, Hongzhi; Zhang, Qinghong

    2012-10-01

    Anatase TiO(2) nanorods with large specific surface areas and high crystallinity have been synthesized by surfactant-free hydrothermal treatment of water-soluble peroxotitanium acid (PTA). X-ray diffraction and TEM analysis showed that all TiO(2) nanorods derived from PTA in different hydrothermal processes were in the anatase phase, and high aspect ratio TiO(2) nanorods with chain-shaped structures were formed at 150 °C for 24 h by oriented growth. The nanorods were fabricated as photoanodes for high-efficiency dye-sensitized solar cells (DSSCs). DSSCs fabricated from the chain-shaped TiO(2) nanorods gave a highest short-circuit current density of 14.8 mA cm(-2) and a maximum energy conversion efficiency of 7.28 %, as a result of the presence of far fewer surface defects and grain boundaries than are present in commercial P25 TiO(2) nanoparticles. Electrochemical impedance spectroscopy also confirmed that DSSCs based on the TiO(2) nanorods have enhanced electron transport properties and a long electron lifetime. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Rod shaped oxovanadium(IV) Schiff base complexes: Synthesis, mesomorphism and influence of flexible alkoxy chain lengths

    NASA Astrophysics Data System (ADS)

    Gupta, Bishop Dev; Datta, Chitraniva; Das, Gobinda; Bhattacharjee, Chira R.

    2014-06-01

    A series of oxovanadium(IV) complexes of bidentate [N,O] donor Schiff-base ligands of the type [VO(L)2], [L = N-(4-n-alkoxysalicylaldimine)-4‧-octadecyloxyaniline, n = 8, 10, 12, 14, 16 and 18] have been synthesized. The compounds were characterized by elemental analyses, Fourier transform infrared spectroscopy (FTIR), 1H, 13C nuclear magnetic resonance (NMR), ultraviolet-visible spectroscopy (UV-Vis), and fast atom bombardment (FAB) mass spectrometry. The mesomorphic behavior of the compounds was studied by polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The ligands and complexes are all thermally stable exhibiting smectic mesomorphism. The ligands 8-OR to16-OR show SmC phase at ∼113-118 °C and an unidentified SmX phase reminiscent of soft crystal at ∼77-91 °C whereas the complexes all showed SmA phases. Interestingly the complexes with C10 and C12 alkoxy chain length exhibited additionally SmC phases also. The melting points of the ligands linearly increases whereas mesophase to isotropic transition temperature decreases as a function of increasing carbon chain length of alkoxy arm while no trend was apparently noticeable for the complexes.

  7. Shape-Controlled Metal-Free Catalysts: Facet-Sensitive Catalytic Activity Induced by the Arrangement Pattern of Noncovalent Supramolecular Chains.

    PubMed

    Geng, Guangwei; Chen, Penglei; Guan, Bo; Jiang, Lang; Xu, Zhongfei; Di, Dawei; Tu, Zeyi; Hao, Weichang; Yi, Yuanping; Chen, Chuncheng; Liu, Minghua; Hu, Wenping

    2017-05-23

    Metal-free catalytic materials have recently received broad attention as promising alternatives to metal-involved catalysts. This is owing to their inherent capability to overcome the inevitable limitations of metal-involved catalysts, such as high sensitivity to poisoning, the limited reserves, high cost and scarcity of metals (especially noble metals), etc. However, the lack of shape-controlled metal-free catalysts with well-defined facets is a formidable bottleneck limiting our understandings on the underlying structure-activity relationship at atomic/molecular level, which thereby restrains their rational design. Here, we report that catalytically active crystals of a porphyrin, 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin, could be shaped into well-defined cubes and sheet-like tetradecahedrons (TDHD), which are exclusively and predominantly enclosed by {101} and {001} facets, respectively. Fascinatingly, compared to the cubes, the TDHDs display substantially enhanced catalytic activity toward water decontamination under visible-light irradiation, although both the architectures have identical crystalline structure. We disclose that such interesting shape-sensitive catalytic activity is ascribed to the distinct spatial separation efficiency of photogenerated electrons and holes induced by single-channel and multichannel charge transport pathways along noncovalent supramolecular chains, which are arranged as parallel-aligned and 2D network patterns, respectively. Our findings provide an ideal scientific platform to guide the rational design of next-generation metal-free catalysts of desired catalytic performances.

  8. Controllable Synthesis of Multiarm Star-Shaped Copolymers Composed of Phosphoester Chains and Their Application on Drug Delivery.

    PubMed

    Zhang, Li; Shi, Dongjian; Shi, Chunling; Dong, Liangliang; Li, Xiaojie; Chen, Mingqing

    2017-03-29

    Novel biodegradable polymers with specific properties, structures, and tailorable designs or modifications are in great demand. Poly(phosphoester)s with good biocompatibility and degradability, as well as other adjustable properties have been studied widely because of their potential in biomedical applications. To meet more versatile and diverse biomedical applications, a novel multiarm star-shaped phosphorester triblock copolymer poly(amido amine)-block-poly(2-butynyl phospholane)-block-poly(2-methoxy phospholane) (PAMAM-PBYP-PMP) is synthesized via organo-catalyzed sequential ring-opening polymerization. Supramolecular micelles with good architectural stability are self-assembled into uniform spherical morphology in aqueous solution. Doxorubicin (DOX) can be encapsulated into the micelles with efficient loading capacity. A slow and sustained release in the environment of simulated intracellular lysosome (pH 5.0 with phosphodiesterase I) is observed. In addition, the copolymers and DOX-loaded supramolecular micelles exhibit low cell-toxicity and excellent anticancer activity toward HeLa cells. As a consequence, this multiarm star-shaped PAMAM-PBYP-PMP has great potential in drug delivery system for tumor treatment.

  9. Magnetically suspended momentum wheels for spacecraft stabilization

    NASA Technical Reports Server (NTRS)

    Henrikson, C. H.; Lyman, J.; Studer, P. A.

    1974-01-01

    Magnetic bearings for spacecraft momentum wheels offer the promise of low friction and unlimited life. This paper describes how magnetic bearings work and their advantages and disadvantages. The present status of magnetic bearings is described and examples are shown of the various and widely-different magnetically suspended momentum wheels that have been built to date. These include wheels whose bearings exhibit high stiffness and wheels with zero-power suspensions. The future of magnetically suspended momentum wheels is discussed including the possibility of wheels with neither spokes nor shaft.

  10. Design and experimental research of the on-line detection system for diamond arc grinding wheel

    NASA Astrophysics Data System (ADS)

    Zhang, Feihu; Li, Chen; Liu, Zhongde; Ren, Lele; Xie, Haisheng

    2016-10-01

    The principle of measuring displacement by eddy current sensor was derived. The calibration experiment was carried out for 5 kinds of different materials, which showed that the linearity of eddy current sensor was better, and the sensitivity of eddy current sensor varied with different materials. Based on the principle of measuring displacement by eddy current sensor, the on-line detection system for diamond circular wheel was designed, and the data acquisition was realized by using LABVIEW software. By moving the eddy current sensor in the vertical direction with the grinding wheel fixed, the coordinate of arc in the grinding wheel was obtained. The radius of the grinding wheel was fitted by using the genetic algorithm, which showed that the fitting results were accurate. The data acquisition of the grinding wheel was carried out in a cycle by fixing the electric eddy current sensor and the circulars of the grinding wheel in different processes, namely before dressing, after dressing and after shaping. The results showed that the circular of the grinding wheel after dressing and after shaping were significantly improved compared with that before dressing.

  11. 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.

  12. 14 CFR 23.731 - Wheels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 23.731 Wheels. (a) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center of gravity....

  13. 14 CFR 27.731 - Wheels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of gravity. (c)...

  14. 14 CFR 25.731 - Wheels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... and nose wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center...

  15. 14 CFR 27.731 - Wheels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of gravity. (c)...

  16. 14 CFR 27.731 - Wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of gravity. (c)...

  17. 14 CFR 23.731 - Wheels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 23.731 Wheels. (a) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center of gravity....

  18. 14 CFR 25.731 - Wheels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... and nose wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center...

  19. 14 CFR 29.731 - Wheels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... landing gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of...

  20. 14 CFR 23.731 - Wheels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... § 23.731 Wheels. (a) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center of gravity....

  1. 14 CFR 29.731 - Wheels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... landing gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of...

  2. 14 CFR 25.731 - Wheels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and nose wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center...

  3. 14 CFR 25.731 - Wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and nose wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center...

  4. 14 CFR 25.731 - Wheels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... and nose wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center...

  5. 14 CFR 27.731 - Wheels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of gravity. (c)...

  6. 14 CFR 29.731 - Wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... landing gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of...

  7. 14 CFR 23.731 - Wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... § 23.731 Wheels. (a) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center of gravity....

  8. 14 CFR 27.731 - Wheels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of gravity. (c)...

  9. 14 CFR 29.731 - Wheels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... landing gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of...

  10. 14 CFR 23.731 - Wheels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 23.731 Wheels. (a) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Design maximum weight; and (2) Critical center of gravity....

  11. 14 CFR 29.731 - Wheels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... landing gear wheel must be approved. (b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with— (1) Maximum weight; and (2) Critical center of...

  12. Propulsion Wheel Motor for an Electric Vehicle

    NASA Technical Reports Server (NTRS)

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

    2016-01-01

    A wheel assembly for an electric vehicle includes a wheel rim that is concentrically disposed about a central axis. A propulsion-braking module is disposed within an interior region of the wheel rim. The propulsion-braking module rotatably supports the wheel rim for rotation about the central axis. The propulsion-braking module includes a liquid cooled electric motor having a rotor rotatable about the central axis, and a stator disposed radially inside the rotor relative to the central axis. A motor-wheel interface hub is fixedly attached to the wheel rim, and is directly attached to the rotor for rotation with the rotor. The motor-wheel interface hub directly transmits torque from the electric motor to the wheel rim at a 1:1 ratio. The propulsion-braking module includes a drum brake system having an electric motor that rotates a cam device, which actuates the brake shoes.

  13. Meals on Wheels Association of America

    MedlinePlus

    ... vulnerable seniors it serves. DOWNLOAD THE INFOGRAPHIC MR. PRESIDENT, COME TAKE A RIDE WITH MEALS ON WHEELS ... Blueprint proposing cuts that could effect our programs, President and CEO of Meals on Wheels America Ellie ...

  14. Compressor wheel assembly for turbochargers

    SciTech Connect

    Joco, F.M.

    1987-11-10

    In a turbocharger having a housing, this patent describes: a rotatable shaft having a threaded end; bearing means for rotatably mounting the shaft to the housing; a boreless turbine wheel secured to an end of the shaft opposite the threaded end; a boreless compressor wheel having a boreless hub supporting a circumferentially arranged array of impeller blades; and an attachment member mounted on the hub generally at one axial end thereof in a position generally centered on a central axis of the hub. The attachment member includes means for attachment to the threaded end of the shaft.

  15. Suspension Parameter Measurements of Wheeled Military Vehicles

    DTIC Science & Technology

    2012-08-01

    just behind the wheel location being tested, and a linear interpolation is made to estimate the motion of the vehicle body directly above the wheel...Military Vehicles, Andreatta, et al. Page 3 of 8 lateral (y) directions on linear rails with circulating balls. The effective coefficient of... friction of these rails is in the range of 0.002. Steer motion of the wheel pad is allowed by a large crossed roller bearing under the wheel pad. The

  16. 49 CFR 229.73 - Wheel sets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) The variation in the circumference of wheels on the same axle may not exceed 1/4 inch (two tape sizes) when applied or turned. (b) The maximum variation in the diameter between any two wheel sets in a three... compensate for wheel diameter variation, the maximum variation may not exceed 11/4 inch. The maximum...

  17. 49 CFR 230.114 - Wheel centers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel centers with divided rims shall be properly fitted with iron or steel filling blocks before the tires are applied, and such filling blocks shall be properly maintained. When shims are inserted between the tire...

  18. 49 CFR 230.114 - Wheel centers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel centers with divided rims shall be properly fitted with iron or steel filling blocks before the tires are applied, and such filling blocks shall be properly maintained. When shims are inserted between the tire...

  19. 49 CFR 229.73 - Wheel sets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Wheel sets. 229.73 Section 229.73 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229.73 Wheel sets. (a...) when applied or turned. (b) The maximum variation in the diameter between any two wheel sets in a...

  20. 49 CFR 229.73 - Wheel sets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Wheel sets. 229.73 Section 229.73 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229.73 Wheel sets. (a...) when applied or turned. (b) The maximum variation in the diameter between any two wheel sets in a...

  1. 49 CFR 229.73 - Wheel sets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Wheel sets. 229.73 Section 229.73 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229.73 Wheel sets. (a...) when applied or turned. (b) The maximum variation in the diameter between any two wheel sets in a...

  2. 49 CFR 229.73 - Wheel sets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Wheel sets. 229.73 Section 229.73 Transportation... TRANSPORTATION RAILROAD LOCOMOTIVE SAFETY STANDARDS Safety Requirements Suspension System § 229.73 Wheel sets. (a...) when applied or turned. (b) The maximum variation in the diameter between any two wheel sets in a...

  3. 49 CFR 230.114 - Wheel centers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Tenders Wheels and Tires § 230.114 Wheel centers. (a) Filling blocks and shims. Driving and trailing wheel centers with divided rims shall be properly fitted with iron or steel filling blocks before the tires are applied, and such filling blocks shall be properly maintained. When shims are inserted between the tire...

  4. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 7 2013-07-01 2013-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  5. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 7 2011-07-01 2011-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  6. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 7 2014-07-01 2014-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  7. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  8. 29 CFR 1915.134 - Abrasive wheels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 7 2012-07-01 2012-07-01 false Abrasive wheels. 1915.134 Section 1915.134 Labor... § 1915.134 Abrasive wheels. This section shall apply to ship repairing, shipbuilding and shipbreaking. (a) Floor stand and bench mounted abrasive wheels used for external grinding shall be provided with...

  9. Getting Off the Hamster Wheel

    ERIC Educational Resources Information Center

    Sammon, Grace

    2005-01-01

    Even with all the external elements of school reform in place, educators can end up spinning their wheels. To make progress, schools must identify the nonnegotiable key elements of their reform plans and use the habits of highly effective schools to turn them into school practice. These habits are: (1) demonstrate high expectations and a vision…

  10. Potter's Wheel I: Art Education.

    ERIC Educational Resources Information Center

    Marinaccio, Louis

    A course in forming medium size pottery on the potter's wheel and developing skill to reproduce matching forms is presented. Abilities which will be expected of the student at the end of the course include: (1) defining important terms relating to pottery, (2) identifying and differentiating between certain aspects of ceramic art, and (3)…

  11. Getting Off the Hamster Wheel

    ERIC Educational Resources Information Center

    Sammon, Grace

    2005-01-01

    Even with all the external elements of school reform in place, educators can end up spinning their wheels. To make progress, schools must identify the nonnegotiable key elements of their reform plans and use the habits of highly effective schools to turn them into school practice. These habits are: (1) demonstrate high expectations and a vision…

  12. Reaction wheels for kinetic energy storage

    SciTech Connect

    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 wheels 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.

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

    NASA Astrophysics Data System (ADS)

    Janczur, R.

    2016-09-01

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

  14. Reaction wheel with HTS bearings for mini-satellite attitude control

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Postrekhin, Yevgeniy; Bui Ma, Ki; Chu, Wei-Kan

    2002-05-01

    We have developed a small reaction wheel, designed to be lightweight, compact and energy efficient. The main innovation is the use of the HTS magnet's bearings that promise low friction so that high momentum storage can be achieved with high spin speed. The bearings consist of seeded growth superconducting discs arranged in rings located above and below the rotating levitated wheel containing ring-magnets embedded at the top and bottom. The reaction wheel is in the shape of a hollow stainless steel cylinder. A brushless dc motor is installed inside the hollow cylinder to provide the necessary torque to the reaction wheel. The maximum design spin speed is 15 000 RPM to store 3.5 J s-1 of angular momentum. Spin-down test of the reaction wheel was performed in air. We have also measured the input power required to sustain rotational speed of the reaction wheel in air. Results from both of these measurements, when extrapolated to full speed in vacuum, indicate that power consumption, even accounting for the needs of the cooling system, is significantly smaller than that for state of the art commercial reaction wheels using mechanical ball bearings.

  15. The method of assessment of the grinding wheel cutting ability in the plunge grinding

    NASA Astrophysics Data System (ADS)

    Nadolny, Krzysztof

    2012-09-01

    This article presents the method of comparative assessment of the grinding wheel cutting ability in the plunge grinding kinematics. A new method has been developed to facilitate multicriterial assessment of the working conditions of the abrasive grains and the bond bridges, as well as the wear mechanisms of the GWAS, which occur during the grinding process, with simultaneous limitation of the workshop tests range. The work hereby describes the methodology of assessment of the grinding wheel cutting ability in a short grinding test that lasts for 3 seconds, for example, with a specially shaped grinding wheel, in plunge grinding. The grinding wheel macrogeometry modification applied in the developed method consists in forming a cone or a few zones of various diameters on its surface in the dressing cut. It presents an exemplary application of two variants of the method in the internal cylindrical plunge grinding, in 100Cr6 steel. Grinding wheels with microcrystalline corundum grains and ceramic bond underwent assessment. Analysis of the registered machining results showed greater efficacy of the method of cutting using a grinding wheel with zones of various diameters. The method allows for comparative tests upon different grinding wheels, with various grinding parameters and different machined materials.

  16. Pin-wheel hexagons: a model for anthraquinone ordering on Cu(111).

    PubMed

    Simenas, M; Tornau, E E

    2013-10-21

    The 4-state model of anthraquinone molecules ordering in a pin-wheel large-pore honeycomb phase on Cu(111) is proposed and solved by Monte Carlo simulation. The model is defined on a rescaled triangular lattice with the lattice constant a being equal to intermolecular distance in the honeycomb phase. The pin-wheel triangle formations are obtained taking into account the elongated shape of the molecules and anisotropic interactions for main two attractive short range (double and single dimeric) H-bond interactions. The long-range intermolecular interactions, corresponding to repulsive dipole-dipole forces, are assumed to be isotropic. Also, a very small (compared to short-range forces) isotropic attractive long-range interaction at the "characteristic" distance of a pore diameter is employed, and its effect carefully studied. This interaction is crucial for a formation of closed porous ordered systems, pin-wheel hexagons in particular. If each side of a pin-wheel hexagon is formed of n parallel molecules, the distance of this characteristic interaction is a√(3n(2)+1). The phase diagrams including different pin-wheel hexagon phases and a variety of other ordered structures are obtained. By changing the distance of characteristic interaction, different ordering routes into the experimental pin-wheel honeycomb phase are explored. The results obtained imply that classical explanation of the origin of the pin-wheel honeycomb phase in terms of some balance of attractive and repulsive forces cannot be totally discounted yet.

  17. The method of assessment of the grinding wheel cutting ability in the plunge grinding

    NASA Astrophysics Data System (ADS)

    Nadolny, Krzysztof

    2012-09-01

    This article presents the method of comparative assessment of the grinding wheel cutting ability in the plunge grinding kinematics. A new method has been developed to facilitate multicriterial assessment of the working conditions of the abrasive grains and the bond bridges, as well as the wear mechanisms of the GWAS, which occur during the grinding process, with simultaneous limitation of the workshop tests range. The work hereby describes the methodology of assessment of the grinding wheel cutting ability in a short grinding test that lasts for 3 seconds, for example, with a specially shaped grinding wheel, in plunge grinding. The grinding wheel macrogeometry modification applied in the developed method consists in forming a cone or a few zones of various diameters on its surface in the dressing cut. It presents an exemplary application of two variants of the method in the internal cylindrical plunge grinding, in 100Cr6 steel. Grinding wheels with microcrystalline corundum grains and ceramic bond underwent assessment. Analysis of the registered machining results showed greater efficacy of the method of cutting using a grinding wheel with zones of various diameters. The method allows for comparative tests upon different grinding wheels, with various grinding parameters and different machined materials.

  18. The Dynamic Tensile Behavior of Railway Wheel Steel at High Strain Rates

    NASA Astrophysics Data System (ADS)

    Jing, Lin; Han, Liangliang; Zhao, Longmao; Zhang, Ying

    2016-11-01

    The dynamic tensile tests on D1 railway wheel steel at high strain rates were conducted using a split Hopkinson tensile bar (SHTB) apparatus, compared to quasi-static tests. Three different types of specimens, which were machined from three different positions (i.e., the rim, web and hub) of a railway wheel, were prepared and examined. The rim specimens were checked to have a higher yield stress and ultimate tensile strength than those web and hub specimens under both quasi-static and dynamic loadings, and the railway wheel steel was demonstrated to be strain rate dependent in dynamic tension. The dynamic tensile fracture surfaces of all the wheel steel specimens are cup-cone-shaped morphology on a macroscopic scale and with the quasi-ductile fracture features on the microscopic scale.

  19. 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.

  20. Comb-shaped conjugates comprising hydroxypropyl cellulose backbones and low-molecular-weight poly(N-isopropylacryamide) side chains for smart hydrogels: synthesis, characterization, and biomedical applications.

    PubMed

    Xu, F J; Zhu, Y; Liu, F S; Nie, J; Ma, J; Yang, W T

    2010-03-17

    Hydroxypropyl cellulose (HPC) possesses a lower critical solution temperature (LCST) above 40 °C, while the poly(N-isopropylacrylamide) (P(NIPAAm)) exhibits a LCST of about 32 °C. Herein, comb-shaped copolymer conjugates of HPC backbones and low-molecular-weight P(NIPAAm) side chains (HPC-g-P(NIPAAm) or HPN) were prepared via atom transfer radical polymerization (ATRP) from the bromoisobutyryl-functionalized HPC biopolymers. By changing the composition ratio of HPC and P(NIPAAm), the LCSTs of HPNs can be adjusted to be lower than the body temperature. The MTT assay from the HEK293 cell line indicated that HPNs possess reduced cytotoxicity. Some of the hydroxyl groups of HPNs were used as cross-linking sites for the preparation of stable HPN hydrogels. In comparison with the HPC hydrogels, the cross-linked HPN hydrogels possess interconnected pore structures and higher swelling ratios. The in vitro release kinetics of fluorescein isothiocyanate-labeled dextran and BSA (or dextran-FITC and BSA-FITC) as model drugs from the hydrogels showed that the HPN hydrogels are suitable for long-term sustained release of macromolecular drugs at body temperature.

  1. Four-wheel drive car

    SciTech Connect

    Ashikawa, N.

    1986-03-25

    A drive train in a four-wheel drive vehicle is described having an engine mounted on one end with a crankshaft oriented transverse to the direction of vehicle travel which consists of: a transmission having an output gear driven by the crankshaft and rotatable around an axis parallel to the axis of the crankshaft; a reduction gear operatively engaged with the output gear; a first differential gear having a gear and being concentrically engaged with the reduction gear to transmit the output of the reduction gear in a divided manner; a second differential gear transmitting power from one output of the differential gear to left and right wheels of the one end of the vehicle; a transmission gear meshing with the gear of the first differential gear for transmitting power from another output of the first differential gear in a direction generally perpendicular to the crankshaft through a propeller shaft to the other end of the vehicle, opposite the one end; a third differential gear receiving power from the propeller shaft for transmitting power to left and right wheels on the other end; and wherein a mesh portion where the transmission gear meshes with the gear of the first differential gear is closer to the crankshaft axis of engine than is the axis of the reduction gear.

  2. Aerodynamic Drag Reduction Apparatus For Wheeled Vehicles In Ground Effect

    SciTech Connect

    Ortega, Jason M.; Salari, Kambiz

    2005-12-13

    An apparatus for reducing the aerodynamic drag of a wheeled vehicle in a flowstream, the vehicle having a vehicle body and a wheel assembly supporting the vehicle body. The apparatus includes a baffle assembly adapted to be positioned upstream of the wheel assembly for deflecting airflow away from the wheel assembly so as to reduce the incident pressure on the wheel assembly.

  3. 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.

  4. 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.

  5. 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).

  6. Analytical investigation of the SAFE diagram for bladed wheels, numerical and experimental validation

    NASA Astrophysics Data System (ADS)

    Bertini, L.; Neri, P.; Santus, C.; Guglielmo, A.; Mariotti, G.

    2014-09-01

    Compressor and turbine bladed wheels interact with the fluid distributed by the stator vanes. They are subject to vibration and fatigue loading, especially when resonance conditions are excited. Avoiding resonance is fundamental when designing bladed wheels. The Campbell diagram approach is too conservative since bladed wheels show many close frequency natural modes, thus it is almost impossible to avoid frequency matching. Singh's Advanced Frequency Evaluation (SAFE) diagram, or interference diagram, also introduces shape matching in addition to the frequency, for resonance prediction, therefore many frequency matching cases can be identified as non-critical and thus tolerated. The present paper explains and demonstrates the SAFE diagram by introducing an analytical expression to identify bladed wheel resonance conditions. The mode shape matching with a harmonic component is investigated by means of specific examples. Symmetry properties of the matching distribution of harmonic indices and mode shapes are also introduced and demonstrated. Finally, a bladed wheel analysis is used for validation, both in FE simulations and experiments.

  7. Determination of Steering Wheel Angles during CAR Alignment by Image Analysis Methods

    NASA Astrophysics Data System (ADS)

    Mueller, M.; Voegtle, T.

    2016-06-01

    Optical systems for automatic visual inspections are of increasing importance in the field of automation in the industrial domain. A new application is the determination of steering wheel angles during wheel track setting of the final inspection of car manufacturing. The camera has to be positioned outside the car to avoid interruptions of the processes and therefore, oblique images of the steering wheel must be acquired. Three different approaches of computer vision are considered in this paper, i.e. a 2D shape-based matching (by means of a plane to plane rectification of the oblique images and detection of a shape model with a particular rotation), a 3D shape-based matching approach (by means of a series of different perspectives of the spatial shape of the steering wheel derived from a CAD design model) and a point-to-point matching (by means of the extraction of significant elements (e.g. multifunctional buttons) of a steering wheel and a pairwise connection of these points to straight lines). The HALCON system (HALCON, 2016) was used for all software developments and necessary adaptions. As reference a mechanical balance with an accuracy of 0.1° was used. The quality assessment was based on two different approaches, a laboratory test and a test during production process. In the laboratory a standard deviation of ±0.035° (2D shape-based matching), ±0.12° (3D approach) and ±0.029° (point-to-point matching) could be obtained. The field test of 291 measurements (27 cars with varying poses and angles of the steering wheel) results in a detection rate of 100% and ±0.48° (2D matching) and ±0.24° (point-to-point matching). Both methods also fulfil the request of real time processing (three measurements per second).

  8. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2017-08-01

    During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of

  10. 49 CFR 230.113 - Wheels and tire defects.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or...

  11. 49 CFR 230.113 - Wheels and tire defects.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

  12. 49 CFR 230.113 - Wheels and tire defects.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

  13. 49 CFR 230.113 - Wheels and tire defects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

  14. 49 CFR 230.113 - Wheels and tire defects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Steam Locomotives and Tenders Wheels and Tires § 230.113 Wheels and tire defects. Steam locomotive and tender wheels or tires...

  15. Control Electronics For Reaction Wheel

    NASA Technical Reports Server (NTRS)

    Chamberlin, Keith

    1995-01-01

    Bidirectional operation achieved with single-polarity main power supply. Control circuitry generates pulse-width-modulated 800-Hz waveforms to drive two-phase ac motor and reaction wheel. Operates partly in response to digital magnitude-and-direction torque command generated by external control subsystem and partly in response to tachometric feedback in form of two once-per-revolution sinusoids with amplitudes proportional to speed. Operation in either of two modes called "normal" and "safehold." In normal mode, drive pulses timed so that, on average over one or few cycles, motor applies commanded torque. In safehold mode, pulses timed to keep motor running at set speed in one direction.

  16. Control Electronics For Reaction Wheel

    NASA Technical Reports Server (NTRS)

    Chamberlin, Keith

    1995-01-01

    Bidirectional operation achieved with single-polarity main power supply. Control circuitry generates pulse-width-modulated 800-Hz waveforms to drive two-phase ac motor and reaction wheel. Operates partly in response to digital magnitude-and-direction torque command generated by external control subsystem and partly in response to tachometric feedback in form of two once-per-revolution sinusoids with amplitudes proportional to speed. Operation in either of two modes called "normal" and "safehold." In normal mode, drive pulses timed so that, on average over one or few cycles, motor applies commanded torque. In safehold mode, pulses timed to keep motor running at set speed in one direction.

  17. The energy wheel in operation

    NASA Astrophysics Data System (ADS)

    Barthelemy, J. P.

    An energy wheel was implemented as an uninterruptible power supply unit for a rural telephone exchange. A high speed rotor, magnetically suspended, inside a vacuum container, is activated by a brushless motor. Being reversible, this motor acts as an electrical energy generator in case of failure or microcuts from the mains. No failure, no maintenance, no detrimental effect of cold winter environment, and satisfactory level of available back up energy are reported. Improvements such as mass reduction, easy implementation, vacuum tightness, and ac supply are identified.

  18. Effect of Vorticity Amplification on Flow Separation from Landing Gear Wheels

    NASA Astrophysics Data System (ADS)

    Feltham, Graham; McCarthy, Philip; Ekmekci, Alis

    2014-11-01

    The flow near the stagnation point of landing gear wheels has been previously shown to support a mechanism for inbound streams of weak vorticity to collect, growth, and amplify into large-scale discrete vortex structures. The current experimental study is an extension to investigate the effects of these vortex structures on the separation characteristics of the flow around the outboard sides of the wheels. Experiments were performed in a water channel with qualitative understanding of the flow topology achieved by employing the hydrogen bubble visualization technique and quantitative measurements performed using Particle Image Velocimetry (PIV). The upstream vorticity source is a platinum wire (d = 100 μm) placed 30 mm upstream of the model wheels. The Reynolds number based on wire diameter is 21 and based on wheel diameter (D = 152 mm) is 32,500. The inbound pair of vorticity streams impinged at the wheel surface where maximum vortex growth and amplification occurs as identified by previous experiments. The growth and shedding of the resulting vortical structures is shown to alter the shape and size of the separation bubbles on the outboard sides of the wheels. A vortex identification and tracking method is applied to map the growth and movement of the observed structures.

  19. 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.

  20. 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…

  1. Next NASA Mars Rover Gets Its Wheels

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Wheels were first attached to NASA's Mars Science Laboratory rover in August 2008. The rover and its descent stage and cruise stage are being assembled and tested at NASA's Jet Propulsion Laboratory, Pasadena, Calif., for launch in 2009.

    The rover has a ground clearance of about 60 centimeters, or 2 feet. The wheel base is 2.2 meters, or 7 feet.

  2. 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…

  3. 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…

  4. 16 CFR 1507.8 - Wheel devices.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 2 2011-01-01 2011-01-01 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...

  5. 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...

  6. 16 CFR 1507.8 - Wheel devices.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 2 2013-01-01 2013-01-01 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...

  7. 16 CFR 1507.8 - Wheel devices.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 2 2014-01-01 2014-01-01 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...

  8. 16 CFR 1507.8 - Wheel devices.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 16 Commercial Practices 2 2012-01-01 2012-01-01 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...

  9. 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…

  10. Retail wheeling: Is this revolution necessary?

    SciTech Connect

    Cudahy, R.D.

    1994-12-31

    As of a former state regulator and a once enthusiastic practitioner of public utility law, I find it fascinating to see the latest nostrum to burst on the electric utility scene: retail wheeling. Wheeling became a personal interest in the Texas interconnection fight of the late seventies and may have led to the interconnection and wheeling provision of the Public Utilities Regulatory Policies Act (PURPA). Retail wheeling contemplates that every electric power customer should be given an opportunity to seek out the lowest cost source of power wherever it can be found. As a practical matter, the drums for retail wheeling are presently being beaten by large industrial users, who believe that they have the capability to find low cost sources and to make advantageous commercial arrangements to acquire electricity. Large industrials have long been fighting the utilities for cheaper electricity, frequently using the threat of self-generation and cogeneration.

  11. Collapsible four wheel electric powered vehicle

    SciTech Connect

    Enix, C.

    1980-06-24

    A collapsible four wheel vehicle is disclosed that is powered by an electrical source , including a storage battery, an electric motor, rear wheels driven by the electric motor, a pair of front wheels having a diameter nearly as great as the diameter of the rear wheels, a resistance bank connected between said battery and said electric motor, a switch means to control the operation of said electric motor, a steering mechanism to steer the front wheels, passenger seat, and a chassis frame on which all of said component parts are mounted and which frame is collapsible in the sense that it may be disassembled easily and quickly into two main sections each of which are foldable into a flat compact unit.

  12. Development of the FASTER Wheeled Bevameter

    NASA Astrophysics Data System (ADS)

    Richter, L.; Eder, V.; Hoheneder, W.; Imhof, B.; Lewinger, W.; Ransom, S.; Saaj, C.; Weclewski, P.; Waclavicek, R.,

    2014-04-01

    This paper describes the development of a Wheeled Bevameter (WB) within the FASTER project (Forward Acquisition of Soil and Terrain Data for Exploration Rovers), funded by the European Union's FP7 programme. In FASTER, novel and innovative concepts for in situ forward sensing of soil properties and terrain conditions in the planned path of a planetary rover are developed. Terrain strength measurements for assessment of the mobility of crosscountry vehicles have decades of heritage on Earth, but typically trafficability of terrains is only gauged by human operators ahead of vehicle operations rather than in-line by probes deployed from the vehicle itself, as is intended for FASTER. For FASTER, a Wheeled Bevameter (WB) has been selected as the terrain sensing instrument for the vehicle. Wheeled Bevameters are suitable for terrain measurements while driving but traditionally have mostly been employed on terrestrial vehicles to evaluate particular wheel designs. The WB as conceived in FASTER uses a dedicated, passive-rolling test wheel (‚test wheel') placed on the terrain as the loading device to enable to determine bearing strength, compressive strength and shear strength of the terrain immediately ahead of the vehicle, as well as rover-terrain interaction parameters used in semi-empirical vehicle-terrain traction models. The WB includes a placement mechanism for the test wheel. The test wheel would remain lowered onto the ground during nominal rover motion, including when climbing and descending slopes. During normal operations, the placement mechanism assumes the function of a passive suspension of the wheel, allowing it to follow the terrain contour. Quantities measured with the WB are: test wheel sinkage (through a laser sensor), test wheel vertical load, test wheel horizontal reaction force, and test wheel rotation rate. Measurements are performed while the rover is in motion. Measured test wheel rotation rate (with appropriate corrections for slight skid) can

  13. Plasma hardening of railway wheel surface

    NASA Astrophysics Data System (ADS)

    Isakaev, E. Kh.; Ivanov, P. P.; Tyuftyaev, A. S.; Paristyi, I. L.; Troitsky, A. A.; Yablonsky, A. E.; Filippov, G. A.

    1998-10-01

    A computer-controlled plasma technology was developed for the treatment of rolling stock wheels, providing the thermal hardening of tread and flange working surfaces. As a result of the plasma treatment the surface hardness of the wheel grows from 255 up to 420-450 HB. Herewith, the wear capability of the wheel metal grows 2-3 times and its resistance to the weariness-driven destruction grows 1.5 times due to the pecularities of the structural state of the steel, arising out of the thermal impact and of the alloying of the steel with nitrogen during the plasma treatment. Installation of several plants based on this technology in engine houses allowed to carry out a full scale experiment in order to assess the running characteristics of treated wheel sets in comparison with plain ones. Wheel life between mounting and truing or dismounting doubles due to plasma hardening.

  14. Reaction wheel design, construction and qualification testing

    NASA Astrophysics Data System (ADS)

    Proper, Ian

    This thesis examines the design, construction, and space-qualification testing of a microsatellite class reaction wheel. A literature review compares both currently and formerly operational, as well as commercially available reaction wheel assemblies, to assess the torque and momentum generation capabilities relative to the masses of the respective units. Several potential software models for a prototype reaction wheel are constructed and compared to the units described in the literature review to determine feasibility of operation. Choosing a particular model, the prototype wheel is then constructed and baseline tests are performed to determine its operational characteristics. Finally, a series of qualification tests are performed: a life test, a vibration test and a thermal vacuum test. These tests aim to validate the ability of the prototype reaction wheel unit to operate for at least a six-month mission in a typical low Earth orbit environment.

  15. Structural variation in cation-assisted assembly of high-nuclearity Mn arsonate and phosphonate wheels.

    PubMed

    Chimamkpam, Theresa O; Clérac, Rodolphe; Mitcov, Dmitri; Twamley, Brendan; Venkatesan, Munuswamy; Schmitt, Wolfgang

    2016-01-28

    Comproportionation reactions between MnCl2 and KMnO4 in the presence of arsonate or phosphonate ligands promote the cation-assisted assembly of high-nuclearity, wheel-shaped or toroidal {Mn8} () and {Mn24} () complexes; the closely corresponding reaction systems provide insights into the complexation behaviour of homologous phosphonate/arsonate ligand species.

  16. 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.

  17. 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.

  18. Medicine Wheels of the Great Plains

    NASA Astrophysics Data System (ADS)

    Vogt, David

    Medicine Wheels are unexplained aboriginal boulder configurations found primarily on hilltops and river valley vistas across the northwest Great Plains of North America. Their varied, complex designs have inspired diverse hypotheses concerning their meaning and purpose, including astronomical ones. While initial "observatory" speculations were unfounded, and quests to "decode" these structures remain unfulfilled and possibly misguided, the Medicine Wheels nevertheless represent a uniquely worthwhile case study in archaeoastronomical theory and method. In addition, emerging technologies for data acquisition and analysis pertinent to Medicine Wheels offer prospectively important new sight lines for the future of archaeoastronomy.

  19. 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)

  20. 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)

  1. 49 CFR 229.75 - Wheels and tire defects.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... may not be used on tires or steel wheels of locomotives, except for the repair of flat spots and worn... 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...

  2. 49 CFR 229.75 - Wheels and tire defects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... may not be used on tires or steel wheels of locomotives, except for the repair of flat spots and worn... 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...

  3. 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.

  4. Dynamics and wheel's slip ratio of a wheel-legged robot in wheeled motion considering the change of height

    NASA Astrophysics Data System (ADS)

    Ding, Xilun; Li, Kejia; Xu, Kun

    2012-09-01

    The existing research on dynamics and slip ratio of wheeled mobile robot (WMR) are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS-II. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS-II in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified. Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height.

  5. Injuries among wheeled shoe users: A comparison with other nonmotorized wheeled activities

    PubMed Central

    Thakore, Siddharth; Tram, Janna; Hagel, Brent E; Kyle, Tania; Senger, Trudi; Belanger, Francois

    2009-01-01

    BACKGROUND AND OBJECTIVE: Nonmotorized wheeled activities are popular among children. However, these activities can result in significant injury if effective injury prevention measures are not taken. Recently, nonmotorized wheeled shoes have become increasingly popular among children. Preliminary research shows that these activities also result in significant injury. The purpose of the present study was to compare the injury profiles of nonmotorized wheeled activities among Canadian children presenting to the emergency department. METHODS: A two-year retrospective study was conducted using data from the Canadian Hospitals Injury Reporting and Prevention Program database, specific to the Alberta Children’s Hospital, Calgary, Alberta. Data were analyzed using cross tabulations of the type and nature of injury, helmet use, age and sex, with type of nonmotorized wheeled activity. RESULTS: The most common mechanism of injury for a nonmotorized wheeled activity was bicycling (66.9%), while wheeled shoe use produced the fewest injuries (2.7%). The upper extremity was the most frequently injured body region in all groups, comprising more than 75% of the injuries in wheeled shoe users and approximately 50% of the injuries in participants of other nonmotorized wheeled activities. Forearm fractures were the most common type of injury. Wheeled shoe users had the greatest proportion of forearm fractures. Helmet use was most prevalent in bicyclists (84.6%) and least prevalent in wheeled shoe users (4.7%). DISCUSSION: Nonmotorized wheeled activities can result in significant morbidity. Results from the present study suggest that wheeled shoe and push scooter activities can result in upper extremity injuries. Protective equipment, particularly wrist guards and helmets, should be used when participating in these activities. PMID:20885801

  6. [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.

  7. Steerability Analysis of Multiaxle Wheeled Vehicles. Report 1. Development of a Soil-Wheel Interaction Model.

    DTIC Science & Technology

    1984-01-01

    configuration of the wheel, and the mechanical properties of the soil (both shearing response and compressibility characteristics). The system of equations ...and the development of empirical equations relating the various parameters of the A problem (Turnage 1972). Unfortunately, these equations are not...on the kinematics -’ of the wheel is neglected. Even in the case of the rigid wheel, there is no general equation that can predict accurately the

  8. Wheels for the Future: Should the U.S. Army Adopt an Armored Wheeled System

    DTIC Science & Technology

    1990-02-05

    firepower, maneuver, and protection. These three measurements of combat power are more defined in six inherent capabilities of armored wheeled systems...AD-A234 372 Wheuls for the Future: Should the U.S. Army Adopt ar, Armored Wheeled System? A MonograpL by Major Glenn Davis Infantry School of...TITLE (nudScutClassification) Wheels For the ýFuture-- Should the US Army Adopt an Armored Wncc led Sybtem?, 2, PERSONAL AUTHCOI S ’ATIA Glenn W, Davis

  9. Progress toward a performance based specification for diamond grinding wheels

    SciTech Connect

    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 of 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.

  10. The influence of wheel/rail contact conditions on the microstructure and hardness of railway wheels.

    PubMed

    Molyneux-Berry, Paul; Davis, Claire; Bevan, Adam

    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.

  11. 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

  12. Big wheels keep on turning

    SciTech Connect

    Casteel, K.

    2008-05-15

    Although the structure of the market for bucketwheel and bucket chain based equipment has changed over the years, design advances have enabled the technology to retain a significant place in the production and distribution of coal and minerals. 4 photos.

  13. UT Biomedical Informatics Lab (BMIL) Probability Wheel

    PubMed Central

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

    2016-01-01

    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. PMID:28105462

  14. 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.

  15. Magnetic Levitation Experiments with the Electrodynamic Wheel

    NASA Astrophysics Data System (ADS)

    Cordrey, Vincent; Gutarra-Leon, Angel; Gaul, Nathan; Majewski, Walerian

    Our experiments explored inductive magnetic levitation using circular Halbach arrays with the strong variable magnetic field on the outer rim of the ring. Such a system is usually called an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We constructed two Electrodynamic Wheels with different diameters and demonstrated that the magnetic interactions produce both lift and drag forces on the EDW which can be used for levitation and propulsion of the EDW. The focus of our experiments is the direct measurement of lift and drag forces to compare with theoretical models using wheels of two different radii. Supported by Grants from the Virginia Academy of Science, Society of Physics Students, Virginia Community College System, and the NVCC Educational Foundation.

  16. 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.

  17. Constant four wheel drive vehicle transaxle

    SciTech Connect

    Weismann, P.H.; Cameron, D.

    1986-04-15

    A dual differential four-wheel drive assembly is described adapted for a two-wheel drive front transaxle vehicle having an internal combustion engine with a transverse oriented crankshaft for driving the vehicle with front and rear pairs of road wheels, a transmission gear unit for the transaxle including transverse input and output shafts, and right and left laterally extending front axle drive shafts, each drive shaft having front wheel mounting means on its outboard end. The dual differential assembly consists of: housing means having a laterally extending passage therethrough aligned on a transverse axis, the housing means having first and second differential casings for associated first and second bevel gear differentials, the casings supported in laterally spaced alignment for rotation about the transverse axis, each first and second differential casing enclosing inboard and outboard side gears in meshing relation with planetary pinion gears, each casing having opposed inboard and outboard axial extensions thereon.

  18. UT Biomedical Informatics Lab (BMIL) Probability Wheel.

    PubMed

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

    2016-01-01

    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.

  19. Installation of Curiosity Wheels and Suspension

    NASA Image and Video Library

    2010-07-05

    With the wheels and suspension system already installed onto one side of NASA Mars rover Curiosity the previous day, spacecraft engineers and technicians prepare the other side mobility subsystem for installation on June 29, 2010.

  20. 21 CFR 880.6910 - Wheeled stretcher.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... platform mounted on a wheeled frame that is designed to transport patients in a horizontal position. The device may have side rails, supports for fluid infusion equipment, and patient securement straps....

  1. 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.

  2. 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.

  3. Wheeled and Tracked Vehicle Endurance Testing

    DTIC Science & Technology

    2014-10-02

    empty trailer, and towing a fully loaded trailer. This will expose the truck tractor to the three main modes in which it would encounter with the...and explosive ordnance disposal. e. Wheeled Truck Tractors and Trailers, Light and Medium: Truck- tractors and all compatible semitrailers ...Vehicles such as the M1088 and MK31 truck- tractors , and M871/M872 semitrailers would fall under this category. f. Wheeled Truck Tractors and

  4. 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…

  5. 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…

  6. 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.

  7. Four-wheel vehicle drive system

    SciTech Connect

    Sasaki, K.; Takimura, K.; Katayama, N.; Tsuchiya, F.

    1987-02-24

    A four-wheel drive system is described for use in a vehicle including a first and second pair of road wheels, a power unit including an output shaft, and a power transmission gear unit including input and output shafts. The input shaft of the power transmission gear unit is selectively connected to the output shaft of the power unit. The output shaft of the power transmission gear unit selectively is in driving engagement with the input shaft of the power transmission gear unit. The four-wheel drive system comprises: an engagement member being rotatable about a rotational axis located in a lateral direction of the vehicle, the engagement member being held in driving engagement with the output shaft of the power transmission gear unit; a central differential gear assembly including a central input member fixed to and coaxially rotatable with the engagement member about the rotational axis of the engagement member and including a first central output member and a second central output member enclosed within the central input member. The first and second central output members are rotatable at different speeds about rotational axes substantially aligned with the rotational axis of the engagement member; and a first wheel differential gear assembly being enclosed within the central input member of the central differential gear assembly and including a first wheel input member being rotatable with the first central output member of the central differential gear assembly about the rotational axis of the engagement member and two first wheel output members.

  8. Retail wheeling: Deja vu all over again?

    SciTech Connect

    Lesser, J.A.; Ainspan, M.D.

    1994-04-01

    Retail wheeling seems unlikely to improve economic efficiency, though it would benefit some large customers with market power. But it is not at all clear whether those benefits would outweigh the costs they engender and - even if they did - whether such a redistribution of wealth would be acceptable. The purpose of this article is to discuss some of the major issues associated with retail wheeling and their implications, in hopes of providing decision makers a better framework with which to evaluate proposed policies. Evaluation of retail wheeling has been hampered in several ways. First, a lack of a clear definition of just what it is. Defining it by analogy (e.g., people shopping for electricity the way they shop for groceries, etc.) merely trivializes the subject. In the abstract, retail wheeling may be thought of as a form of shopping, although one must be concerned that, like the classic `bait and switch,` the product purchased may not be the same one that`s advertised. Second, evaluating the benefits and the costs of retail wheeling requires answering at least one basic question: Compared to what? To attempt a comparison of some sort, one can again return to a framework for the environmental externalities debates. Those debates can be framed in terms of two recurrent, though unfortunately often unstated paths: economic efficiency and equity; i.e., how will retail wheeling change overall welfare, and will those changes in welfare be distributed `fairly`?

  9. 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.

  10. Demisable Reaction-Wheel Assembly

    NASA Technical Reports Server (NTRS)

    Roder, Russell; Ahronovich, Eliezer; Davis, Milton C., III

    2008-01-01

    A document discusses the concept of a demisable motor-drive-and-flywheel assembly [reaction-wheel assembly (RWA)] used in controlling the attitude of a spacecraft. Demisable as used here does not have its traditional legal meaning; instead, it signifies susceptible to melting, vaporizing, and/or otherwise disintegrating during re-entry of the spacecraft into the atmosphere of the Earth so as not to pose a hazard to anyone or anything on the ground. Prior RWAs include parts made of metals (e.g., iron, steel, and titanium) that melt at high temperatures and include structures of generally closed character that shield some parts (e.g., magnets) against re-entry heating. In a demisable RWA, the flywheel would be made of aluminum, which melts at a lower temperature. The flywheel web would not be a solid disk but would have a more open, nearly-spoke-like structure so that it would disintegrate more rapidly; hence, the flywheel rim would separate more rapidly so that parts shielded by the rim would be exposed sooner to re-entry heating. In addition, clearances between the flywheel and other components would be made greater, imparting a more open character and thus increasing the exposure of those components.

  11. Shape memory polymers

    DOEpatents

    Wilson, Thomas S.; Bearinger, Jane P.

    2017-08-29

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  12. Shape memory polymers

    DOEpatents

    Wilson, Thomas S.; Bearinger, Jane P.

    2015-06-09

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  13. 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…

  14. Cohesions and Friction Angles of Martian Regolith from MER Wheel Trenches and Wheel Scuffs

    NASA Astrophysics Data System (ADS)

    Sullivan, R.; Anderson, R.; Biesiadecki, J.; Bond, T.; Stewart, H.

    2010-03-01

    We analyzed all MER wheel trenches and wheel scuffs along both MER traverses to derive cohesions and friction angles for martian regolith. Friction angles at both MER sites are 30-37 degrees; cohesions generally are 10 kPa or less.

  15. Diamond wheel wear sensing with acoustic emission --wheel wear mechanisms and the effects of process variables

    SciTech Connect

    Tang, Jianshe; Dornfeld, D.; Syoji, Katsuo

    1996-12-31

    The wear of diamond wheels has significant influence on the surface finish of ground ceramics and the resulting subsurface fracture damage. For optimization and control of the grinding process it is necessary to monitor the wear states of the grinding wheels. A project on diamond wheel wear sensing with acoustic emission was started recently in the Laboratory of Manufacturing Automation at the University of California at Berkeley. The main aims of the project are: (a) to identify the possible wheel wear patterns at different combinations of bond materials, grits, and grinding conditions; (b) to develop suitable AE signal processing methods to extract the AE features to represent the wheel wear characteristics, and establish a strategy for using AE for in-process monitoring of diamond wheel wear in grinding of ceramics. This paper presents the results of part of the project. It mainly focuses on the diamond wheel wear mechanisms, the effects of process variables including basic wheel elements and grinding parameters, and the relationship with AErms and AE frequency content.

  16. 75 FR 56469 - Safety Zone; Ohio River, Wheeling, WV, Wheeling Heritage Port Sternwheel Foundation Fireworks...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Ohio River, Wheeling, WV, Wheeling Heritage... Ohio River extending the full width of the river. The safety zone is needed to protect spectators and... Marker 90.5 on the Ohio River extending the full width of the river. The safety zone is needed to...

  17. 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…

  18. 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.

  19. Project considerations and design of systems for wheeling cogenerated power

    SciTech Connect

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

    1994-08-01

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

  20. Wheel running, food intake, and body weight in male rats.

    PubMed

    Looy, H; Eikelboom, R

    1989-02-01

    The acquisition of wheel running, its effects on food intake and body weight, and the effects of wheel deprivation, were examined in male rats. Running increased during the first 15 days of access, then plateaued. When wheels were unlocked after 10 days of deprivation, running was reduced, but quickly recovered to original levels. Animals first given wheel access 49 days into the study ran little, with no increase over days. Food intake dropped each time with wheel access, but recovered to control levels over 10-14 days. Wheel deprivation resulted in a temporary hyperphagia. With wheel access, weight initially dropped and was then maintained at a reduced percentage of homecage-housed animals. In male rats wheel access appears to have temporary effects on food intake, and long term effects on weight. Marked differences in the activity of same-age rats suggest that wheel running is in part a function of housing history.

  1. Wire Electrical Discharge Truing of Metal Bond Diamond Grinding Wheels

    SciTech Connect

    McSpadden, SB

    2002-01-24

    Cylindrical wire EDM profile truing of the metal bond diamond wheel for precision form grinding of ceramics is presented in this report. First a corrosion-resistant, precise spindle with the high-electrical current capability for wire EDM truing of grinding wheel was fabricated. An arc profile was adopted in order to determine form tolerances capabilities of this process. Results show the wire EDM process can generate {micro}m-scale precision form on the diamond wheel efficiently. The wheel, after truing, was used to grind silicon nitride. Grinding forces, surface finish of ground components, and wheel wear were measured. The EDM trued wheel showed a reduction in grinding force from that of the stick dressed wheel. Surface finishes between the two truing methods were similar. In the beginning of the grinding, significant wheel wear rate was identified. The subsequent wheel wear rate stabilized and became considerably lower.

  2. Parametric study of the factors affecting wheel slip and sinkage for the Mars Exploration Rovers

    NASA Astrophysics Data System (ADS)

    Johnson, J.; Kulchitsky, A. V.; Duvoy, P.; Arvidson, R. E.; Iagnemma, K.; Senatore, C.

    2013-12-01

    In 2004 two rovers landed on Mars to conduct scientific investigations of the Martian surface in an effort to better understand its surface geology, climate, and potential to support life. During the mission, both rovers experienced events of severe rover wheel sinkage and slip in the highly variable Martian regolith. Mars Exploration Rover (MER) Opportunity experienced high wheel slip and sinkage when it attempted to cross a series of wind-blown ripples. MER rover Spirit became immobilized after breaking through a soil crust into highly deformable poorly sorted sands. Events of MER rover wheel high-sinkage and slip make mobility difficult, creating challenges for rover drive planners and increasing the risk of ending a mission early due to a lack of rover mobility. The ARTEMIS (Adams- based Rover Terramechanics and Mobility Interaction Simulator) MER rover simulation tool was developed in an effort to improve the ability to simulate rover mobility on planetary surfaces to aid planning of rover drives and to extract a rover if it becomes embedded in soil [1]. While ARTEMIS has demonstrated its ability to simulate a wide variety of rover mobility scenarios using a library of empirically based terramechanics subroutines and high-resolution digital elevation maps of Mars, it has had less success at simulating the high-sinkage, high-slip conditions that pose the highest risk to rover mobility. To improve ARTEMIS's high-slip, high-sinkage terramechanics subroutines, the COUPi discrete element method (DEM) model of MER rover wheel motion under conditions of high-sinkage and slip is being used to examine the effects of soil particle size distribution (PSD), shape, and bulk density. DEM simulations of MER wheel digging tests and the resistance forces of penetrometers in soil have demonstrated the importance of particle shape and bulk density on soil strength [2, 3]. Simulations of the densification of particle beds as functions of the spread (ratio of largest to smallest

  3. 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

  4. Brush-Wheel Samplers for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Rivellini, Tommaso

    2003-01-01

    A report proposes brush-wheel mechanisms for acquiring samples of soils from remote planets. In simplest terms, such a mechanism would contain brush wheels that would be counter-rotated at relatively high speed. The mechanism would be lowered to the ground from a spacecraft or other exploratory vehicle. Upon contact with the ground, the counter-rotating brush wheels would kick soil up into a collection chamber. Thus, in form and function, the mechanism would partly resemble traditional street and carpet sweepers. The main advantage of using of brush wheels (in contradistinction to cutting wheels or other, more complex mechanisms) is that upon encountering soil harder than expected, the brushes could simply deflect and the motor(s) could continue to turn. That is, sufficiently flexible brushes would afford resistance to jamming and to overloading of the motors used to rotate the brushes, and so the motors could be made correspondingly lighter and less power hungry. Of course, one could select the brush stiffnesses and motor torques and speeds for greatest effectiveness in sampling soil of a specific anticipated degree of hardness.

  5. Synthesis of nanometer-scale porphyrin wheels of variable size.

    PubMed

    Hori, Takaaki; Peng, Xiaobin; Aratani, Naoki; Takagi, Akihiko; Matsumoto, Takuya; Kawai, Tomoji; Yoon, Zin Seok; Yoon, Min-Chul; Yang, Jaesung; Kim, Dongho; Osuka, Atsuhiro

    2008-01-01

    Starting from 1,3-phenylene linked diporphyrin zinc(II) complex 2ZA, repeated stepwise Ag I-promoted coupling reactions provided linear oligomers from 2nZA up to 128ZA. Of these zigzag shaped porphyrin arrays, the Ag I-promoted intramolecular cyclization reaction of 2 nZA (n=5, 6, 8, 9, 12, and 16) under dilute conditions gave the corresponding cyclic porphyrin wheels C2nZA (n=5, 6, 8, 9, 12, and 16), whereas large arrays 2nZA (n=24, 32, and 48) did not provide cyclic porphyrin products. These large discrete porphyrin arrays and wheels were fully characterized by means of 1H NMR spectroscopy, MALDI-TOF mass spectrometry, UV/Vis absorption spectroscopy, GPC-HPLC analysis, and the scanning tunneling microscopy (STM) technique. The STM images of C12ZA and C18ZA reveal their large circular structures. In the cyclic structures of C2nZA in solution, however, the gradual decrease in fluorescence quantum yields and fluorescence lifetimes are observed, reflecting some conformational heterogeneities. Collectively, the present work provides an important contribution to the construction of fully covalently linked large cyclic arranged porphyrin arrays with ample electronic interactions as a model of light-harvesting antenna.

  6. Stability of Castering Wheels for Aircraft Landing Gears, Special Report

    NASA Technical Reports Server (NTRS)

    Kantrowitz, Arthur

    1937-01-01

    In many installations of castering rubber-tired wheels there is a tendency for the wheel to oscillate violently about the spindle axis. This phenomenon, popularly called 'shimmy,' has occurred in some airplane tail wheels and has been corrected in two ways: first by the application of friction in the spindles of the tail wheels; and, second, by locking the wheels while taxiing at high speeds. Shimmy is common with the large wheels used as nose wheels in tricycle landing gears and, since it is impossible to lock the wheels, friction in the nose-wheel spindle has been the sole means of correction. Because the nose wheel is larger than the conventional tail wheel and usually carries a greater load, the larger amounts of spindle friction necessary to prevent shimmy are objectionable. the present paper presents a theoretical and experimental study of the problem of the stability of castering wheels for airplane landing gears. On the basis of simplified assumptions induced from experimental observations, a theoretical study has been made of the shimmy of castering wheels. The theory is based on the discovery of a phenomenon called 'kinematic shimmy' and is compared quantitatively with the results of model experiments. Experimental checks, using a model having low-pressure tires, are reported and the applicability of the results to full scale is discussed. Theoretical methods of estimating the spindle viscous damping and spindle solid friction necessary to avoid shimmy - lateral freedom - is introduced.

  7. Precision truing of diamond wheel with sharp edge

    NASA Astrophysics Data System (ADS)

    Ge, Cheng; Guo, Bing; Zhao, QIngliang; Chen, Bing; Wang, Jinhu

    2014-08-01

    Diamond wheel with sharp edge has small contour structures, which can lead to fast wear of wheel in the grinding process. Traditional truing methods are hard to apply to this kind of wheels. Therefore, as for the difficulty of precision truing of diamond wheel with sharp edge, the novel methods for resin and metal bonded diamond wheels with sharp edge are presented, respectively. In this experiment, a conditioning procedure with rare metal alloy block Ta was used to true the resin bonded diamond grinding wheel and in the same way Nb alloy block was utilized to complete rough truing of metal bonded diamond grinding wheel. Then a CNC truing technique with rotational green carbide (GC) truing stick was applied to precise truing of metal bonded diamond grinding wheel. Methods mentioned above were measured in order to evaluate the performance of truing. Geometric features of the wheel sharp edge were duplicated on the organic glass (PMMA) in order to measure and calculate the radius of the sharp edge. The edge radius of trued resin bonded wheel and metal bonded wheel is perceived as an important assessment. The experiments results revealed that the edge radius of 12.45μm for the resin bonded wheel and the edge radius of 30.17μm for the metal bonded wheel could be achieved.

  8. Power wheel with double action valve in conjunction with a drill bit

    SciTech Connect

    Weinert, F.

    1984-03-06

    A power wheel is described with double action valves comprises a heat engine in form of a rotating vessel mounted to an axis supported at one end to a frame, or joined into a pipe or flexible hose as the other end is faced up by a side gear confronting a second side gear both gears intermeshing through a plurality of pinion gears mounted between first and second ends of both shafts, the pinion gears are activated through expansion valves concealing the shaft of the pinion gear, a plurality of expansion valves mounted on said outer perimeter on radial axis, each of said expansion valve including: A cylinder with mechanical float valves A piston with piston rods penetrating the cylinder A valve control bar activated by stroke action of pistons A helical mechanism to rotate spindle shaft by stroke action of pistons A spindle shaft with two pawl bushings A pinion gear joined to said spindle shaft A drive gear for delivering useful work output mounted to the shaft of the vessel or a drill bit whereby the power wheel with double action valves is put at the top of the drill bit called platform to match both side gears to rotate the drill bit by blocking rotation of the power wheel by means of a plurality of chain saws installed inside the outer circumference of the power wheel whereby chain saw is extended to the outside of the outer circumference of the drill bit activated through spindle shaft penetrating expansion valves on one side as the other side of the shaft drives pinion gears to rotate the power wheel or drill bit, whereby stored fluid inside the vessel is heated to expand fluid whereby the volume exchange of the fluid activates piston inside the expansion valve by separating the pressurized fluid from the depressurized fluid, whereby the depressurized fluid is cooled inside a radiator to contract into relaxed stage.

  9. Grain edge detection of diamond grinding wheel

    NASA Astrophysics Data System (ADS)

    Zhou, Lijun; Cui, Changcai; Huang, Chunqi; Huang, Hui; Ye, Ruifang

    2013-01-01

    The topograpgy characterization of grinding wheel grain is indispensable for precision grinding, it depends on accurate edge detecting and recognition of abrasive grains from wheel bond to a large extent. Due to different reflective characteristics arising among different materials, difference between maximum and minimum intensity (Δ ) of diamond is larger than that of bond. This paper uses a new method for grain edge detection of resin-bonded diamond grinding wheel that combines the improved Canny operator in Method of Maximum Classes Square Error (called as OTSU) with ΔI obtained by the white light interferometry (WLI). The experimental results show that the method based on improved Canny operator can effectively detect the edge of diamond grain.

  10. Slow Progress in Dune (Right Rear Wheel)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The right rear wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's rear hazard identification camera over a period of several days. The wheel is largely hidden by a cable bundle. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  11. 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.

  12. 14 CFR 23.497 - Supplementary conditions for tail wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... tail wheel, bumper, or an energy absorption device is provided to show compliance with § 23.925(b), the... absorption device; and (2) The supporting structure of the tail wheel, bumper, or energy absorption...

  13. 14 CFR 23.497 - Supplementary conditions for tail wheels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... tail wheel, bumper, or an energy absorption device is provided to show compliance with § 23.925(b), the... absorption device; and (2) The supporting structure of the tail wheel, bumper, or energy absorption...

  14. 14 CFR 23.497 - Supplementary conditions for tail wheels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... tail wheel, bumper, or an energy absorption device is provided to show compliance with § 23.925(b), the... absorption device; and (2) The supporting structure of the tail wheel, bumper, or energy absorption...

  15. 14 CFR 23.497 - Supplementary conditions for tail wheels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... tail wheel, bumper, or an energy absorption device is provided to show compliance with § 23.925(b), the... absorption device; and (2) The supporting structure of the tail wheel, bumper, or energy absorption...

  16. 14 CFR 23.497 - Supplementary conditions for tail wheels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... tail wheel, bumper, or an energy absorption device is provided to show compliance with § 23.925(b), the... absorption device; and (2) The supporting structure of the tail wheel, bumper, or energy absorption...

  17. 14 CFR 23.499 - Supplementary conditions for nose wheels.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Structure Ground Loads § 23.499 Supplementary conditions for nose wheels. In determining the ground loads on nose wheels and affected supporting structures, and assuming that the shock absorbers and tires are...

  18. 14 CFR 23.499 - Supplementary conditions for nose wheels.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Structure Ground Loads § 23.499 Supplementary conditions for nose wheels. In determining the ground loads on nose wheels and affected supporting structures, and assuming that the shock absorbers and tires are...

  19. 14 CFR 23.499 - Supplementary conditions for nose wheels.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Structure Ground Loads § 23.499 Supplementary conditions for nose wheels. In determining the ground loads on nose wheels and affected supporting structures, and assuming that the shock absorbers and tires are...

  20. 14 CFR 23.499 - Supplementary conditions for nose wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Structure Ground Loads § 23.499 Supplementary conditions for nose wheels. In determining the ground loads on nose wheels and affected supporting structures, and assuming that the shock absorbers and tires are...

  1. 14 CFR 23.499 - Supplementary conditions for nose wheels.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Structure Ground Loads § 23.499 Supplementary conditions for nose wheels. In determining the ground loads on nose wheels and affected supporting structures, and assuming that the shock absorbers and tires are...

  2. Evaluation of the 30 Ton CHA Crane Wheel Axle Modification

    SciTech Connect

    RICH, J.W.

    2002-06-04

    An existing design for eccentric bushings was utilized and updated as necessary to accommodate minor adjustment as required to correct wheel alignment on the North West Idler wheel. The design is revised to install eccentric bushings on only one end.

  3. 19. Credit Pelton Water Wheel Company. Photocopy of drawing (perspective) ...

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

    19. Credit Pelton Water Wheel Company. Photocopy of drawing (perspective) showing layout of powerhouse in 1901. (Pelton Water Wheel Company, Catalog, 11th ed., 1909, p. 75). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  4. 76. Credit FM. Detail showing belts running from water wheel ...

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

    76. Credit FM. Detail showing belts running from water wheel to governor and from water wheel to tachometer (foreground). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  5. Tandem wheel drop-legs for standard truck trailer

    NASA Technical Reports Server (NTRS)

    Cantwell, W.; Selstad, R.

    1970-01-01

    Tandem wheel drop-leg device provides a semitrailer with fore and aft mobility that allows it to be moved without a prime mover. The modified drop-legs have trunnion dual wheels and an adjustable brace.

  6. Development of a magnetically suspended momentum wheel

    NASA Technical Reports Server (NTRS)

    Hamilton, S. B.

    1973-01-01

    An engineering model of a magnetically suspended momentum wheel was designed, fabricated, and tested under laboratory conditions. The basic unit consisted of two magnet bearings, a sculptured aluminum rotor, brushless dc spin motor, and electronics. The magnet bearings, utilizing rare-earth cobltrat-samarium magnets were active radially and passive axially. The results of the program showed that momentum wheels with magnetic bearings are feasible and operable, and that magnetic bearings of this type are capable of being used for applications where high capacity, high stiffness, and low power consumption are required. The tests performed developed criteria for improved performance for future designs.

  7. Optically trapped and driven paddle-wheel

    NASA Astrophysics Data System (ADS)

    Asavei, Theodor; Nieminen, Timo A.; Loke, Vincent L. Y.; Stilgoe, Alexander B.; Bowman, Richard; Preece, Daryl; Padgett, Miles J.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2013-06-01

    We demonstrate the control and rotation of an optically trapped object, an optical paddle-wheel, with the rotation direction normal to the beam axis. This is in contrast to the usual situation where the rotation is about the beam axis. The paddle-wheel can be optically driven and moved to any position in the field of view of the microscope, which can be of interest for various biological applications where controlled application of a fluid flow is needed in a particular location and in a specific direction. This is of particular interest in signal transduction studies in cells, especially when a cell is flat and spread out on a surface.

  8. Nonlinear oscillatory processes in wheeled vehicles

    NASA Astrophysics Data System (ADS)

    Mikhlin, Yu. V.; Mitrokhin, S. G.

    2011-04-01

    The free damped vibrations of a wheeled vehicle with independent suspension are analyzed with allowance for the nonlinear characteristics of the suspension springs and shock absorbers. The vibrations of a wheeled vehicle with a suspension with smooth nonlinear characteristics are studied for a model with seven degrees of freedoms. The skeleton curves and nonlinear normal modes are obtained. For a model with two degrees of freedoms (quarter-car) that corresponds to axisymmetric vibrations, the nonlinear normal modes are found in the case of a shock absorber with nonsmooth nonlinear characteristic

  9. Wheelchair wheels for use on sand.

    PubMed

    Hillman, M

    1994-05-01

    Mobility over sand and other rough surfaces can be a major problem for people in wheelchairs. From tests with a simple prototype, model tests and theoretical calculations the following observations were made for an attendant propelled chair. The rolling resistance of a wheelchair on sand may be improved by pulling, rather than pushing the chair. The use of a ball wheel at the front improves the rolling resistance, though standard large diameter rear wheels give acceptable performance. From these observations a prototype device for fitment to a standard wheelchair has been designed.

  10. Simple 2-D navigation for wheeled vehicles

    SciTech Connect

    Klarer, P.R.

    1988-01-01

    This paper describes a simple algorithm to perform navigation in a two-dimensional world model. The algorithm utilizes a simple geometric approach which is first applied to a bicycle. The equations are then expeanded to apply to 3- and 4-wheeled vehicles with ''conventional'' steering mechanism (such as the Ackerman steering geometry in the 4-wheeled case). Calculations for omnidirectional robots which utilize differential odometry and differential drive are described as well. Practical considerations and sources of error are discussed, as are possible extensions of this method to a three-dimensional world model. 5 refs., 8 figs.

  11. 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.

  12. Wheeling rates based on marginal-cost theory

    SciTech Connect

    Merrill, H.M.; Erickson, B.W. )

    1989-11-01

    Knowledge of what rates for wheeling electric power would be, if based on marginal costs, is vital in the debate on how wheeling should be priced. This paper presents the first extensive computations of marginal costs of wheeling, and of rates based on these marginal costs. Sensitivities to losses, constraints, load levels, amount of power wheeled, revenue reconciliation, etc., are examined in the context of two case studies.

  13. 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.

  14. 32. DETAIL OF MAIN DRIVE WHEELS AND BELT TENSIONING DEVICE ...

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

    32. DETAIL OF MAIN DRIVE WHEELS AND BELT TENSIONING DEVICE OF MAIN POWER TRAIN, LOOKING SOUTHEAST, LOOKING FORM BEHIND THE CLASSIFIER. THESE WHEELS DROVE THE BULL WHEELS ON THE STAMP BATTERIES ABOVE. THE TENSIONING DEVICE AT CENTER RIGHT CONTROLLED THE SPEED OF THE STAMPS. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

  15. 76 FR 29265 - Certain Steel Wheels From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-20

    ... COMMISSION Certain Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the... threatened with material injury by reason of imports from China of certain steel wheels, provided for in... the United States is materially retarded, by reason of imports from China of certain steel wheels...

  16. 77 FR 27249 - Certain Steel Wheels From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-09

    ... COMMISSION Certain Steel Wheels From China Determinations On the basis of the record \\1\\ developed in the... of imports of certain steel wheels from China, provided for in subheading 8708.70 of the Harmonized... notification of preliminary determinations by Commerce that imports of certain steel wheels from China...

  17. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... axles and manufactured before July 25, 1980, are not required to have brakes on the front wheels... 49 Transportation 5 2012-10-01 2012-10-01 false Brakes required on all wheels. 393.42 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.42 Brakes required on all wheels. (a) Every commercial...

  18. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... on the front wheels. However, these vehicles must meet the requirements of § 393.52. (2) Motor... 49 Transportation 5 2010-10-01 2010-10-01 false Brakes required on all wheels. 393.42 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.42 Brakes required on all wheels. (a) Every commercial...

  19. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... axles and manufactured before July 25, 1980, are not required to have brakes on the front wheels... 49 Transportation 5 2013-10-01 2013-10-01 false Brakes required on all wheels. 393.42 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.42 Brakes required on all wheels. (a) Every commercial...

  20. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... manufactured before July 25, 1980, are not required to have brakes on the front wheels. However, these vehicles... 49 Transportation 5 2011-10-01 2011-10-01 false Brakes required on all wheels. 393.42 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.42 Brakes required on all wheels. Link to an amendment...

  1. 49 CFR 393.42 - Brakes required on all wheels.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... axles and manufactured before July 25, 1980, are not required to have brakes on the front wheels... 49 Transportation 5 2014-10-01 2014-10-01 false Brakes required on all wheels. 393.42 Section 393... ACCESSORIES NECESSARY FOR SAFE OPERATION Brakes § 393.42 Brakes required on all wheels. (a) Every commercial...

  2. A Vane-Wheel Propulsor for a Naval Auxiliary

    DTIC Science & Technology

    1989-09-01

    wheel propulsor is in the repropulsion of the cruise ship QE2. We have called the QE2 vane-wheel application infamous because five of the seven vane...and the type of the ship concerned. Van Beek and Lips [51 presented the repropulsion of the cruise ship QE-2 using two CP propellers with a vane wheel

  3. 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.

  4. Slight Movement by Spirit Right-Front Wheel, Sol 2113

    NASA Image and Video Library

    2009-12-15

    Diagnostic tests were run on the right-rear wheel and right-front wheel on NASA Spirit. The right-rear wheel continued to show no motion in the latest tests and exhibited very high resistance in the motor winding.

  5. 14 CFR 23.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false One-wheel landing conditions. 23.483... Ground Loads § 23.483 One-wheel landing conditions. For the one-wheel landing condition, the airplane is... this attitude, the ground reactions must be the same as those obtained on that side under § 23.479. ...

  6. 14 CFR 25.497 - Tail-wheel yawing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.497 Tail-wheel yawing. (a) A vertical ground reaction equal to the static load on the tail wheel, in combination with a side component of equal... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Tail-wheel yawing. 25.497 Section 25.497...

  7. 14 CFR 25.497 - Tail-wheel yawing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.497 Tail-wheel yawing. (a) A vertical ground reaction equal to the static load on the tail wheel, in combination with a side component of equal... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Tail-wheel yawing. 25.497 Section 25.497...

  8. 14 CFR 23.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false One-wheel landing conditions. 23.483... Ground Loads § 23.483 One-wheel landing conditions. For the one-wheel landing condition, the airplane is... this attitude, the ground reactions must be the same as those obtained on that side under § 23.479. ...

  9. 14 CFR 25.497 - Tail-wheel yawing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.497 Tail-wheel yawing. (a) A vertical ground reaction equal to the static load on the tail wheel, in combination with a side component of equal... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Tail-wheel yawing. 25.497 Section 25.497...

  10. 14 CFR 23.483 - 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. 23.483... Ground Loads § 23.483 One-wheel landing conditions. For the one-wheel landing condition, the airplane is... this attitude, the ground reactions must be the same as those obtained on that side under § 23.479. ...

  11. 14 CFR 25.497 - Tail-wheel yawing.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.497 Tail-wheel yawing. (a) A vertical ground reaction equal to the static load on the tail wheel, in combination with a side component of equal... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Tail-wheel yawing. 25.497 Section 25.497...

  12. 14 CFR 23.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false One-wheel landing conditions. 23.483... Ground Loads § 23.483 One-wheel landing conditions. For the one-wheel landing condition, the airplane is... this attitude, the ground reactions must be the same as those obtained on that side under § 23.479. ...

  13. 14 CFR 25.497 - Tail-wheel yawing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.497 Tail-wheel yawing. (a) A vertical ground reaction equal to the static load on the tail wheel, in combination with a side component of equal... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Tail-wheel yawing. 25.497 Section 25.497...

  14. 49 CFR 229.75 - Wheels and tire defects.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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... measured from tread to the top of the flange. (i) Tires less than 11/2 inches thick. (j) Rims less than 1...

  15. 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

  16. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a) General requirements—(1) Machine guarding. Abrasive wheels shall be used only on machines provided...

  17. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 5 2014-07-01 2014-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a) General requirements—(1) Machine guarding. Abrasive wheels shall be used only on machines provided...

  18. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 5 2013-07-01 2013-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a) General requirements—(1) Machine guarding. Abrasive wheels shall be used only on machines provided...

  19. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels... Institute, B7.1-1970, Safety Code for the Use, Care and Protection of Abrasive Wheels, and paragraph (d)...

  20. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 5 2011-07-01 2011-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a) General requirements—(1) Machine guarding. Abrasive wheels shall be used only on machines provided...

  1. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels... Institute, B7.1-1970, Safety Code for the Use, Care and Protection of Abrasive Wheels, and paragraph (d)...

  2. 29 CFR 1910.215 - Abrasive wheel machinery.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Abrasive wheel machinery. 1910.215 Section 1910.215 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Machinery and Machine Guarding § 1910.215 Abrasive wheel machinery. (a) General requirements—(1) Machine guarding. Abrasive wheels shall be used only on machines provided...

  3. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels... Institute, B7.1-1970, Safety Code for the Use, Care and Protection of Abrasive Wheels, and paragraph (d)...

  4. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels... Institute, B7.1-1970, Safety Code for the Use, Care and Protection of Abrasive Wheels, and paragraph (d)...

  5. 29 CFR 1926.303 - Abrasive wheels and tools.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Abrasive wheels and tools. 1926.303 Section 1926.303 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Tools-Hand and Power § 1926.303 Abrasive wheels... Institute, B7.1-1970, Safety Code for the Use, Care and Protection of Abrasive Wheels, and paragraph (d)...

  6. Spacing trials using the Nelder Wheel

    Treesearch

    Walter B. Mark

    1983-01-01

    The Nelder Wheel is a single tree systematic experimental design. Its major application is for plantation spacing experiments. The design allows for the testing of a number of spacings in a small area. Data obtained is useful in determining the response of stem diameter and crown diameter to spacing. Data is not compatible with data from conventional plots unless...

  7. Wheeling Your Way Through the Outdoors

    ERIC Educational Resources Information Center

    Falk, John H.

    1974-01-01

    Describes the use of the "Plant Wheel" by the University of California Botanical Garden as a means of providing elementary school children with a structured activity as they explore the Garden at their own pace. This activity accommodates the children's curiosity, energy, and attention span. (JR)

  8. Drowsy Driving: Asleep at the Wheel

    MedlinePlus

    ... work. No one knows the exact moment when sleep comes over their body. Falling asleep at the wheel is ... you experience any of these warnings signs, pull over to rest or change drivers . ... of Sleep Medicine. How often do Americans fall asleep while ...

  9. Investigating Functions with a Ferris Wheel

    ERIC Educational Resources Information Center

    Johnson, Heather Lynn; Hornbein, Peter; Azeem, Sumbal

    2016-01-01

    The authors provide a dynamic Ferris wheel computer activity that teachers can use as an instructional tool to help students investigate functions. They use a student's work to illustrate how students can use relationships between quantities to further their thinking about functions.

  10. 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.

  11. 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.

  12. 21 CFR 880.6910 - Wheeled stretcher.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Wheeled stretcher. 880.6910 Section 880.6910 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Miscellaneous...

  13. Rolling Friction on a Wheeled Laboratory Cart

    ERIC Educational Resources Information Center

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  14. Fifth-wheel fork truck adapter

    NASA Technical Reports Server (NTRS)

    Smith, P. L.

    1969-01-01

    Standard fifth wheel mounted on a rectangular steel structure adapted for use with a fork lift truck provides a fast, safe, and economical way of maneuvering semitrailers in close quarters at plants and warehouses. One operator can move and locate a semitrailer without dismounting from a fork lift truck.

  15. A permeable rotating-wheel solvent extractor

    NASA Technical Reports Server (NTRS)

    Kahn, D. R.; Nady, L. A.

    1972-01-01

    Column-type device reported employs circular permeable structures of wire mesh screen for extracting solvents from systems with low density differences and low interfacial tensions. Rotating screen wheels of structure fasten to shaft; stationary screen structures are supported by circular bands connected by radial metal arms.

  16. Control augmentation for lateral control wheel steering

    NASA Technical Reports Server (NTRS)

    Foulkes, R. H., Jr.

    1981-01-01

    Flight control system design for lateral control wheel steering is discussed. Two alternate designs are presented. The first design is a roll-rate command, bank-angle hold system with a wings-level track-hold submode. The second is a curved-track-hold system. Design details and real-time flight simulator results are included.

  17. Reinventing the Wheel: Design and Problem Solving

    ERIC Educational Resources Information Center

    Blasetti, Sean M.

    2010-01-01

    This article describes a design problem that not only takes students through the technological design process, but it also provides them with real-world problem-solving experience as it relates to the manufacturing and engineering fields. It begins with a scenario placing the student as a custom wheel designer for an automotive manufacturing…

  18. Reinventing the Wheel: Design and Problem Solving

    ERIC Educational Resources Information Center

    Blasetti, Sean M.

    2010-01-01

    This article describes a design problem that not only takes students through the technological design process, but it also provides them with real-world problem-solving experience as it relates to the manufacturing and engineering fields. It begins with a scenario placing the student as a custom wheel designer for an automotive manufacturing…

  19. Progress in Wind-Wheel Turbines

    NASA Technical Reports Server (NTRS)

    Frost, W.; Kessel, P. A.

    1983-01-01

    New wind turbine offers important advantages over conventional propeller wind turbines according to theoretical studies and tests of small working models. Project results are described in final report now available. Windwheel turbines consists of bladed wheel, main housing, two forward ducts (front concentrators), two side ducts (side concentrators) and base to support and elevate housing.

  20. Rolling Friction on a Wheeled Laboratory Cart

    ERIC Educational Resources Information Center

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  1. Before the Outline--The Writing Wheel.

    ERIC Educational Resources Information Center

    Rae, Colleen

    1986-01-01

    To help students write more effectively, a technique for writing from thesis statements is described that requires students to create a picture of a wheel. The hub is a word that is the essence of the topic; the spokes are concrete examples; and the tire is the thesis statement. (MLW)

  2. Wheeling Your Way Through the Outdoors

    ERIC Educational Resources Information Center

    Falk, John H.

    1974-01-01

    Describes the use of the "Plant Wheel" by the University of California Botanical Garden as a means of providing elementary school children with a structured activity as they explore the Garden at their own pace. This activity accommodates the children's curiosity, energy, and attention span. (JR)

  3. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Defective wheel. 215.103 Section 215.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension...

  4. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Defective wheel. 215.103 Section 215.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension...

  5. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective wheel. 215.103 Section 215.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension...

  6. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Defective wheel. 215.103 Section 215.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension...

  7. 49 CFR 215.103 - Defective wheel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Defective wheel. 215.103 Section 215.103 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension...

  8. Investigating Functions with a Ferris Wheel

    ERIC Educational Resources Information Center

    Johnson, Heather Lynn; Hornbein, Peter; Azeem, Sumbal

    2016-01-01

    The authors provide a dynamic Ferris wheel computer activity that teachers can use as an instructional tool to help students investigate functions. They use a student's work to illustrate how students can use relationships between quantities to further their thinking about functions.

  9. 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.

  10. 77 FR 67400 - RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as Wheeling Corrugating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-09

    ... Employment and Training Administration RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as..., 2012, applicable to workers of RG Steel Wheeling, LLC, a division of RG Steel, LLC, doing business as... RG Steel, LLC, doing business as Wheeling Corrugating Company, Beech Bottom, West Virginia,...

  11. Rotational jumps of the tyrosine side chain in crystalline enkephalin. /sup 2/H NMR line shapes for aromatic ring motion in solids

    SciTech Connect

    Rice, D.N.; Wittebort, R.J.; Griffin, R.G.; Meirovitch, E.; Stimson, E.R.; Meinwald, Y.C.; Freed, J.H.; Scheraga, H.A.

    1981-12-30

    Deuterium NMR spectra of polycrystalline (tyrosine-3,5-/sup 2/H/sub 2/)(Leu/sup 5/)enkephalin show that the aromatic tyrosyl ring of this pentapeptide is executing 180/sup 0/ flips about the C/sup ..beta../-C/sup ..gamma../ axis in the solid state. Specifically, the axially symmetric powder pattern observed at low temperature collapses to an axially asymmetric pattern with eta approx. = 0.6 at high temperature. Computer simulation of the NMR line shapes, which account for spectral distortions induced by the quadrupole echo technique, indicate that at room temperature the flipping rate is approximately 5 x 10/sup 4/ s/sup -1/ and that it increases to about 10/sup 6/ s/sup -1/ at 101 /sup 0/C.

  12. Applied grinding wheel performance evaluation for optical fabrication

    SciTech Connect

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

    1996-06-11

    We are collaborating with the Center for Optics Manufacturing (Rochester NY) to develop fine diamond grinding wheels for spherical grinding of glass optics. A standardized method for evaluating wheel performance includes in-process acoustic emission (AE). This paper includes recent AE measurements taken during the evaluation of several fine diamond grinding wheels and discusses how this new information might relate to the physical performance of the wheels. An interesting observation is also reported on the surface topography of worn bronze wheels using an interferometric profiler.

  13. Image processing-based wheel steer angle detection

    NASA Astrophysics Data System (ADS)

    Shu, Tian; Zheng, Yongan; Shi, Zhongke

    2013-10-01

    Wheel steer angle information is crucial for the estimation of vehicle sideslip. Different from previous detection methods using angle sensors, this work presents a new wheel steer angle detection method based on a computer vision system providing image sequences recorded by a camera mounted on a car. The difference between wheel steering right and left is analyzed to determine steer direction while wheel steer angle in the image is derived from the information of the wheel contour extracted by the threshold segmentation and edge extraction. Experimental results show the efficiency of the proposed approach.

  14. Ultracold few fermionic atoms in needle-shaped double wells: spin chains and resonating spin clusters from microscopic Hamiltonians emulated via antiferromagnetic Heisenberg and t-J models

    NASA Astrophysics Data System (ADS)

    Yannouleas, Constantine; Brandt, Benedikt B.; Landman, Uzi

    2016-07-01

    Advances with trapped ultracold atoms intensified interest in simulating complex physical phenomena, including quantum magnetism and transitions from itinerant to non-itinerant behavior. Here we show formation of antiferromagnetic ground states of few ultracold fermionic atoms in single and double well (DW) traps, through microscopic Hamiltonian exact diagonalization for two DW arrangements: (i) two linearly oriented one-dimensional, 1D, wells, and (ii) two coupled parallel wells, forming a trap of two-dimensional, 2D, nature. The spectra and spin-resolved conditional probabilities reveal for both cases, under strong repulsion, atomic spatial localization at extemporaneously created sites, forming quantum molecular magnetic structures with non-itinerant character. These findings usher future theoretical and experimental explorations into the highly correlated behavior of ultracold strongly repelling fermionic atoms in higher dimensions, beyond the fermionization physics that is strictly applicable only in the 1D case. The results for four atoms are well described with finite Heisenberg spin-chain and cluster models. The numerical simulations of three fermionic atoms in symmetric DWs reveal the emergent appearance of coupled resonating 2D Heisenberg clusters, whose emulation requires the use of a t-J-like model, akin to that used in investigations of high T c superconductivity. The highly entangled states discovered in the microscopic and model calculations of controllably detuned, asymmetric, DWs suggest three-cold-atom DW quantum computing qubits.

  15. (1)H, (13)C, (15)N backbone and side chain NMR resonance assignments for E73 from Sulfolobus spindle-shaped virus ragged hills, a hyperthermophilic crenarchaeal virus from Yellowstone National Park.

    PubMed

    Schlenker, Casey; Menon, Smita; Lawrence, C Martin; Copié, Valérie

    2009-12-01

    Crenarchaeal viruses are commonly found in hyperthermal acidic environments such as those of Yellowstone National Park. These remarkable viruses not only exhibit unusual morphologies, but also display extreme genetic diversity. However, little is known about crenarchaeal viral life cycles, virus-host interactions, and their adaptation to hyperthermophilic environments. In an effort to better understand the functions of crenarchaeal viruses and the proteins encoded by their genomes, we have undertaken detailed structural and functional studies of gene products encoded in the open reading frames of Sulfolobus spindle-shaped virus ragged hills. Herein, we report ((15)N, (13)C, (1)H) resonance assignments of backbone and side chain atoms of a 19.1 kDa homodimeric E73 protein of SSVRH.

  16. Wheel pose measurement based on cross structure light

    NASA Astrophysics Data System (ADS)

    Zhao, Qiancheng; Ding, Xun; Wang, Xian; Zhao, Yafeng

    2016-01-01

    It's necessary for automobile to detect and adjust four-wheel alignment parameters regularly, due to the significant effect on improving stability, enhancing security and reducing tire wear of automobiles. In order to measure the parameters that determined by relative position and posture of four wheels to the automobile cab, this paper proposes a method which applies monocular vision of linear structure light to wheel pose measurement. Firstly, space coordinates of feature point cloud are calculated out from the principle of structured light. Then, an algorithm is designed to determine the normal vector of wheel tangent plane and measure the wheel pose. Finally, actual experiments that by evaluation of adjusted wheel angle measurement are carried out to verify the system accuracy. The corresponding studies can be applied in designing and developing 3D four-wheel alignment system that based on structured light.

  17. 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

  18. 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

  19. Use of power assist wheels results in increased distance traveled compared with conventional manual wheeling.

    PubMed

    Levy, Charles E; Buman, Matthew P; Chow, John W; Tillman, Mark D; Fournier, Kimberly A; Giacobbi, Peter

    2010-08-01

    To evaluate the impact of power assist wheels on the distance traveled by manual wheelchair users and analyze potential cofactors in the magnitude of response and to test the hypothesis that wheelers would travel significantly further with power assist wheels. A 16-wk A (Preintervention)-B (Intervention)-A (Postintervention) repeated measures design. Seven women and 13 men (age, 43 +/- 15 yrs) full-time wheelers participated. During the pre- and postintervention phases (4 wks each), participants used their own unaltered manual wheelchairs. During the 8-wk intervention phase, the manual wheels were replaced with power assist wheels. Daily distance was measured with bicycle-style odometers. A composite score of laboratory wheelchair tasks was used to classify wheelchair performance. Mixed model repeated measures analysis of variance analyzed changes across phases of the trial. A post hoc analysis tabulated the amount of days wheelers exceeded their individual daily averages in each phase by two SDs. Wheelers traveled significantly greater distances during the intervention phase compared with pre- or postintervention phases regardless of baseline wheelchair performance. Wheelers who demonstrated higher baseline wheelchair performance traveled lesser average distances in the first 2 wks after receiving power assist wheels than in the subsequent 6 wks. Wheelers exceeded their individual daily averages per phase on a significantly greater number of days during the intervention phase. Power assist wheels enabled wheelers to travel farther and to travel beyond their usual distances on more days. Further studies may be strengthened by taking into account the 2-wk "adjustment phase" for power assist wheels.

  20. The development of a material model and wheel-tissue interaction for simulating wheeled surgical robot mobility.

    PubMed

    Rentschler, Mark E; Reid, John D

    2009-04-01

    In vivo surgical robot wheel and tissue interaction was studied using a nonlinear finite element model. A liver material model, derived from laboratory experiments, was implemented as a viscoelastic material. A finite element simulation of this laboratory test confirmed the accuracy of the liver material model. This material model was then used as the tissue model to study wheel performance. A helical wheel moving on the liver model was used to replicate laboratory experiments that included several different slip ratios and applied loads. The drawbar force produced in this model showed good agreement with the physical tests. These results have provided the baseline for studying how changes in wheel geometry, such as tread height, tread spacing and wheel diameter, affect drawbar force and ultimately wheel performance. These results will be used in future surgical robot wheel designs.

  1. Vibration analysis of a wheel composed of a ring and a wheel-plate modelled as a three-parameter elastic foundation

    NASA Astrophysics Data System (ADS)

    Noga, Stanisław; Bogacz, Roman; Markowski, Tadeusz

    2014-12-01

    The free in-plane vibrations of circular rings with wheel-plates as generalised elastic foundations are studied using analytical methods and numerical simulations. The three-parameter Winkler elastic layer is proposed as a mathematical model of the foundation. The effects of rotary inertia and shear deformation are included in the analytical model of the system. The motion equations of systems are derived on the basis of the thin ring theory and Timoshenko's theory. The separation of variables method is used to find general solutions to the free vibrations. Elaborated analytical models are used to determine the natural frequencies and the natural mode shapes of vibrations of an arbitrarily chosen set of simplified models of aviation gears and railway wheels. The eigenvalue problem is formulated and solved by using a finite element representation for each simplified model. The results for these models are discussed and compared. The proposed solutions are verified by experimental investigation. It is important to note that the solutions proposed here could be useful to engineers dealing with the dynamics of aviation gears, railway wheels and other circular ring systems.

  2. Slow Progress in Dune (Left Front Wheel)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The left front wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's front hazard identification camera over a period of several days. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  3. Slow Progress in Dune (Left Rear Wheel)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The left rear wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's rear hazard identification camera over a period of several days. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  4. Slow Progress in Dune (Right Front Wheel)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The right front wheel of NASA's Mars Exploration Rover Opportunity makes slow but steady progress through soft dune material in this movie clip of frames taken by the rover's front hazard identification camera over a period of several days. The sequence starts on Opportunity's 460th martian day, or sol (May 10, 2005) and ends 11 days later. In eight drives during that period, Opportunity advanced a total of 26 centimeters (10 inches) while spinning its wheels enough to have driven 46 meters (151 feet) if there were no slippage. The motion appears to speed up near the end of the clip, but that is an artifact of individual frames being taken less frequently.

  5. 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.

  6. Flow Visualization around a Simplified Two-Wheel Landing Gear

    NASA Astrophysics Data System (ADS)

    Ekmekci, Alis; Feltham, Graham

    2013-11-01

    The flow topology around a simplified two-wheel landing gear model is investigated experimentally by employing the hydrogen bubble flow visualization technique in a recirculating water channel. The landing gear test model consists of two identical wheels, an axle, a main strut and a support strut. The flow Reynolds number based on wheel diameter is 31,500 and wheels with varying geometric details are considered. Flow structures have been identified through analysis of long-time video recordings and linked to the model geometry. In the flow region above the wheels (wing side), the flow in the inter-wheel region either separates prematurely from the inner surfaces of the wheels and forms slant vortices in the near-wake, or remains attached till the aft wheel perimeter. Inclusion of interior wheel wells are found to result in a jet-like ejection as a result of the interaction with the axle and main strut. In the flow region below the wheels (ground side) the near wake contains periodically forming, complex, large-scale structures.

  7. Maternity care calendar wheel. Improved obstetric wheel developed in British Columbia.

    PubMed Central

    Grzybowski, S.; Nout, R.; Kirkham, M.

    1999-01-01

    PROBLEM BEING ADDRESSED: Gestational calendar "wheels" are not well designed for routine prenatal care or for presenting the uncertainties of predicting date of delivery. OBJECTIVE OF PROGRAM: To design and pilot-test a new gestational calendar wheel that predicts the range of normal due dates in a way that reflects the biological realities of pregnancy. The calendar has prompts that could facilitate provision of antenatal care, support prenatal education, and guide the timing of induction for pregnancies past their due dates. MAIN COMPONENTS OF PROGRAM: The calendar sets out the key issues to be addressed with patients during pregnancy. It is designed to be photocopied while set to patients' dates: patients keep one copy; another is placed in their charts. The probability of delivering on a given date is presented graphically and as a percentage likelihood of giving birth during specified intervals. Twelve practising physicians, 12 residents, and 10 pregnant women pilot-tested and evaluated the wheel. Their responses were favourable. CONCLUSIONS: The Maternity Care Calendar wheel is a substantial advance on existing obstetric calendar wheels. It incorporates evidence-based information that should facilitate prenatal care, promote prenatal education, and foster realistic expectations about the likely timing of delivery. Early in the pregnancy, it can help establish the timing of induction for pregnancies past their due dates. Further testing of the calendar's effectiveness in improving patient outcomes is needed. PMID:10099805

  8. Influence of wheel configuration on wheelchair basketball performance: wheel stiffness, tyre type and tyre orientation.

    PubMed

    Mason, B S; Lemstra, M; van der Woude, L H V; Vegter, R; Goosey-Tolfrey, V L

    2015-04-01

    The aim of the current investigation was to explore the lateral stiffness of different sports wheelchair wheels available to athletes in 'new' and 'used' conditions and to determine the effect of (a) stiffness, (b) tyre type (clincher vs. tubular) and (c) tyre orientation on the physiological and biomechanical responses to submaximal and maximal effort propulsion specific to wheelchair basketball. Eight able-bodied individuals participated in the laboratory-based testing, which took place on a wheelchair ergometer at two fixed speeds (1.1 and 2.2 m s(-1)). Outcome measures were power output and physiological demand (oxygen uptake and heart rate). Three participants with experience of over-ground sports wheelchair propulsion also performed 2 × 20 m sprints in each wheel configuration. Results revealed that wheels differed significantly in lateral stiffness with the 'new' Spinergy wheel shown to be the stiffest (678.2 ± 102.1 N mm(-1)). However the effects of stiffness on physiological demand were minimal compared to tyre type whereby tubular tyres significantly reduced the rolling resistance and power output in relation to clincher tyres. Therefore tyre type (and subsequently inflation pressure) remains the most important aspect of wheel specification for athletes to consider and monitor when configuring a sports wheelchair.

  9. Finite Element Modeling of the Bulk Magnitization of Railroad Wheels to Improve Test Conditions for Magnetoacoustic Residual Stress Measurements

    NASA Technical Reports Server (NTRS)

    Fulton, J. P.; Wincheski, B.; Namkung, M.; Utrata, D.

    1992-01-01

    The magnetoacoustic measurement technique has been used successfully for residual stress measurements in laboratory samples. However, when used to field test samples with complex geometries, such as railroad wheels, the sensitivity of the method declines dramatically. It has been suggested that the decrease in performance may be due, in part, to an insufficient or nonuniform magnetic induction in the test sample. The purpose of this paper is to optimize the test conditions by using finite element modeling to predict the distribution of the induced bulk magnetization of railroad wheels. The results suggest that it is possible to obtain a sufficiently large and uniform bulk magnetization by altering the shape of the electromagnet used in the tests. Consequently, problems associated with bulk magnetization can be overcome, and should not prohibit the magnetoacoustic technique from being used to make residual stress measurements in railroad wheels. We begin by giving a brief overview of the magnetoacoustic technique as it applies to residual stress measurements of railroad wheels. We then define the finite element model used to predict the behavior of the current test configuration along with the nonlinear constitutive relations which we obtained experimentally through measurements on materials typically used to construct both railroad wheels and electromagnets. Finally, we show that by modifying the pole of the electromagnet it is possible to obtain a significantly more uniform bulk magnetization in the region of interest.

  10. The influence of surface roughness on the contact stiffness and the contact filter effect in nonlinear wheel-track interaction

    NASA Astrophysics Data System (ADS)

    Lundberg, Oskar E.; Nordborg, Anders; Lopez Arteaga, Ines

    2016-03-01

    A state-dependent contact model including nonlinear contact stiffness and nonlinear contact filtering is used to calculate contact forces and rail vibrations with a time-domain wheel-track interaction model. In the proposed method, the full three-dimensional contact geometry is reduced to a point contact in order to lower the computational cost and to reduce the amount of required input roughness-data. Green's functions including the linear dynamics of the wheel and the track are coupled with a point contact model, leading to a numerically efficient model for the wheel-track interaction. Nonlinear effects due to the shape and roughness of the wheel and the rail surfaces are included in the point contact model by pre-calculation of functions for the contact stiffness and contact filters. Numerical results are compared to field measurements of rail vibrations for passenger trains running at 200 kph on a ballast track. Moreover, the influence of vehicle pre-load and different degrees of roughness excitation on the resulting wheel-track interaction is studied by means of numerical predictions.

  11. Wheel Force Transducer Research and Development

    DTIC Science & Technology

    2012-03-02

    develop, validate and calibrate cost effective field test equipment for measuring tire characteristics on vehicles whilst driving off-road. The proposed... field test equipment for measuring tire characteristics on vehicles whilst driving off-road. The proposed wheel force transducer is an important...of simulating off-road terrain under laboratory conditions, field test equipment, that can determine tire characteristics on vehicles whilst driving

  12. Mountain Bike Wheel Endurance Testing and Modeling

    DTIC Science & Technology

    2012-01-01

    simulating bike and rider mass, is added using weights supported near the wheel hub axis. The pivoting assembly is raised and lowered on pneumatic ...A lower frequency oscillation with period ~0.2 seconds corresponds with the 5 Hz natural frequency of the weighted pivot arm on the pneumatic tire...Empirical Model for Determining the Radial Force-Deflection Characteristics of Off-Road bicycle Tyres ,” International Journal of Vehicle Design, 17 (4

  13. Improved Safety of Railroad Car Wheels.

    DTIC Science & Technology

    1981-12-01

    were discussed in papers presented at the 6th International Wheelset Congress (Ref 15 and 16). In this section the application of the thermal and...a New Solid Wheel Apt to the Most Severe Operative Conditions", 6th International Wheelset Congress, Colorado Springs, Colorado (October 1978). 3...Strength of Wheelsets ", 6th International Wheelset Congress, Colorado Springs, Colorado (October 1978). 17. Wetenkamp, H. R. and Kipp, R. M. "Safe Thermal

  14. Rotating target wheel for the FMA

    SciTech Connect

    Back, B.B.; Davids, C.N.; Falout, J.

    1995-08-01

    In anticipation of high intensity beams that will be available from the PII-ECR source injector to ATLAS, a new rotating target wheel was developed for the sliding seal chamber at the FMA. The wheel is 9 inch in diameter and contains up to ten targets. The rotation of the wheel is achieved by a DC motor, a ferrofluidic feedthrough, and a gear mechanism that allows both target rotation and changing the target angle relative to the beam. The nominal rotation speed is 1000 RPM, although higher speeds can be achieved if necessary. The assembly is equipped with an absolute encoder which is read out via a newly developed CAMAC module. This module provides the following main functions: (1) a TTL signal to be used for sweeping the beam when a target frame is about to pass through the beam, (2) a read-out of the target position that can be included in the data event structure, (3) programmable set points for the beam-off signal. The system is presently being tested and will be used in experiments scheduled for March 1995.

  15. 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.

  16. A gimbaled low noise momentum wheel

    NASA Astrophysics Data System (ADS)

    Bichler, U.; Eckardt, T.

    1993-05-01

    The bus actuators are the heart and at the same time the Achilles' heel of accurate spacecraft stabilization systems, because both their performance and their perturbations can have a deciding influence on the achievable pointing accuracy of the mission. The main task of the attitude actuators, which are mostly wheels, is the generation of useful torques with sufficiently high bandwidth, resolution and accuracy. This is because the bandwidth of the whole attitude control loop and its disturbance rejection capability is dependent upon these factors. These useful torques shall be provided, without - as far as possible - parasitic noise like unbalance forces and torques and harmonics. This is because such variable frequency perturbations excite structural resonances which in turn disturb the operation of sensors and scientific instruments. High accuracy spacecraft will further require bus actuators for the three linear degrees of freedom (DOF) to damp structural oscillations excited by various sources. These actuators have to cover the dynamic range of these disturbances. Another interesting feature, which is not necessarily related to low noise performance, is a gimballing capability which enables, in a certain angular range, a three axis attitude control with only one wheel. The herein presented Teldix MWX, a five degree of freedom Magnetic Bearing Momentum Wheel, incorporates all the above required features. It is ideally suited to support, as a gyroscopic actuator in the attitude control system, all High Pointing Accuracy and Vibration Sensitive space missions.

  17. A gimbaled low noise momentum wheel

    NASA Technical Reports Server (NTRS)

    Bichler, U.; Eckardt, T.

    1993-01-01

    The bus actuators are the heart and at the same time the Achilles' heel of accurate spacecraft stabilization systems, because both their performance and their perturbations can have a deciding influence on the achievable pointing accuracy of the mission. The main task of the attitude actuators, which are mostly wheels, is the generation of useful torques with sufficiently high bandwidth, resolution and accuracy. This is because the bandwidth of the whole attitude control loop and its disturbance rejection capability is dependent upon these factors. These useful torques shall be provided, without - as far as possible - parasitic noise like unbalance forces and torques and harmonics. This is because such variable frequency perturbations excite structural resonances which in turn disturb the operation of sensors and scientific instruments. High accuracy spacecraft will further require bus actuators for the three linear degrees of freedom (DOF) to damp structural oscillations excited by various sources. These actuators have to cover the dynamic range of these disturbances. Another interesting feature, which is not necessarily related to low noise performance, is a gimballing capability which enables, in a certain angular range, a three axis attitude control with only one wheel. The herein presented Teldix MWX, a five degree of freedom Magnetic Bearing Momentum Wheel, incorporates all the above required features. It is ideally suited to support, as a gyroscopic actuator in the attitude control system, all High Pointing Accuracy and Vibration Sensitive space missions.

  18. 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.

  19. Driver distance from the steering wheel: perception and objective measurement.

    PubMed Central

    Segui-Gomez, M; Levy, J; Roman, H; Thompson, K M; McCabe, K; Graham, J D

    1999-01-01

    OBJECTIVES: This study assessed the accuracy of driver perceptions of the distance between the driver's nose and the steering wheel of the vehicle as a factor in considering driver disconnection of an airbag contained in the steering wheel for preventing injury to the driver in an accident. METHODS: A cross-sectional survey of 1000 drivers was done to obtain perceived and objective measurements of the distance between the driver's nose and the steering wheel of the vehicle. RESULTS: Of 234 drivers who believed that they sat within 12 inches of the steering wheel, only 8 (3%) actually did so, whereas of 658 drivers who did not believe that they sat within 12 inches of the wheel, 14 (2%) did so. Shorter drivers were more likely than taller ones to both underestimate and overestimate their seating distance. CONCLUSIONS: Considerable misperception of drivers' distance from the wheel indicates that drivers should objectively measure this distance. PMID:10394328

  20. 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.

  1. Evaluating ultrasonic test indications in a combustion turbine wheel

    SciTech Connect

    Perry, C.; Hartsell, E.

    1985-07-01

    In March 1983, Savannah Electric and Power Company's three-year-old combustion turbine was dismantled for inspection and maintenance. At that time, the unit had 2034 fired starts and 9693 fired hours on it. The rotating assembly was shipped to the manufacturer's service shop for the inspection and maintenance work. During the course of the inspection, the first and second stage wheels were straight-beam ultrasonic tested with no indications found. Subsequently, the wheels were intensively angle-beam ultrasonic tested and two indications were detected in the first stage wheel. The manufacturer recommended retiring the wheel from service. The power company suggested that since the same testing had been done on the wheel before purchase, the same imperfections may have existed then. This article discusses this disagreement and how it eventually led to premature scrapping of the wheel.

  2. A Wavelet-Based Methodology for Grinding Wheel Condition Monitoring

    SciTech Connect

    Liao, T. W.; Ting, C.F.; Qu, Jun; Blau, Peter Julian

    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 different 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.

  3. Coupled Disturbance Modelling And Validation Of A Reaction Wheel Model

    NASA Astrophysics Data System (ADS)

    Zhang, Zhe; Aglietti, Gugliemo S.

    2012-07-01

    Microvibrations of a RWA are usually studied in either hard-mounted or coupled conditions, although coupled wheel-structure disturbances are more representative than the hard-mounted disturbances. The coupled analysis method of the wheel-structure is not as well developed as the hard-mounted one. A coupled disturbance analysis method is proposed in this paper. One of the most important factors in coupled disturbance analysis - the accelerance or dynamic mass of the wheel is measured and results are validated with an equivalent FE model. The wheel hard-mounted disturbances are also measured from a vibration measurement platform particularly designed for this study. Wheel structural modes are solved from its analytical disturbance model and validated with the test results. The wheel-speed dependent accelerance analysis method is proposed.

  4. 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.

  5. Multi-Material Anisotropic Friction Wheels for Omnidirectional Ground Vehicles

    DTIC Science & Technology

    2010-10-01

    Multi-material Anisotropic Friction Wheels for Omnidirectional Ground Vehicles Genya Ishigami*1, Jim Overholt*2, Karl Iagnemma*3 *1 Institute...Massachusetts Ave., Cambridge, MA 02139 USA Abstract: In this paper, a novel omnidirectional vehicle with anisotropic friction wheels is presented...proposed wheel enables a vehicle to realize omnidirectional motion (i.e. the vehicle can move any direction within the plane—forward, back, or

  6. 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.

  7. Neutron Scattering Collimation Wheel Instrument for Imaging Research

    NASA Astrophysics Data System (ADS)

    Van Every, E.; Deyhim, A.

    2016-09-01

    The design of a state-of-the-art selector wheel instrument to support the area of neutron imaging research (neutron radiography/ tomography) is discussed. The selector wheel is installed on the DINGO Radiography instrument at the Bragg Institute HB2 beamline at ANSTO in Sidney Aus. The selector wheel consists of a single axis drum filled with a wax/steel shielding mixture and six square cutouts for neutron optics and a larger solid shielding sector to act as a shutter. This paper focuses on the details of design and shielding of the selector wheel.

  8. 5. Transmission wheel on southeast wall of Oil House. ...

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

    5. Transmission wheel on southeast wall of Oil House. - Delaware, Lackawanna & Western Railroad, Scranton Yards, Oil House, 650 feet Southeast of Cliff & Mechanic Streets, Scranton, Lackawanna County, PA

  9. Dither Helps Compensate For Friction In Reaction Wheel

    NASA Technical Reports Server (NTRS)

    Stetson, John B., Jr.

    1994-01-01

    Dither control and generator unit incorporated into reaction-wheel attitude-control system to help compensate for error caused by friction in reaction-wheel bearings at and near zero speed of wheel. Reaction-wheel attitude-control system designed primarily to maintain desired orientation of spacecraft but also useful in maintaining desired orientation of terrestrial antenna, optical instrument, or other device on aircraft, ship, land vehicle, or other moving platform. Alternating torque sufficient to overcome static friction applied at low speed.

  10. EXTERIOR ELEVATION AND OBLIQUE PERSPECTIVE, LOOKING NORTH, WITH DRIVE WHEELS ...

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

    EXTERIOR ELEVATION AND OBLIQUE PERSPECTIVE, LOOKING NORTH, WITH DRIVE WHEELS IN FOREGROUND. - Norfolk & Southern Steam Locomotive No. 1218, Norris Yards, East of Ruffner Road, Irondale, Jefferson County, AL

  11. 51. Credit JTL. View of Doble wheel housing, exciter, generator, ...

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

    51. Credit JTL. View of Doble wheel housing, exciter, generator, switchboard with overhead field rheostat (above). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  12. Contribution to the theory of tail-wheel shimmy

    NASA Technical Reports Server (NTRS)

    Melzer, M

    1954-01-01

    A basic theoretical and experimental investigation is made of the shimmy behavior of a swiveling landing gear, the experimental tests being conducted with a small wheel mounted over a continuous belt. Effects of wheel loading, rolling velocity, rearward position of the wheel with respect to the swivel axis, tire elasticity, and torsional flexibility of the fuselage are investigated both experimentally and theoretically. A major theoretical conclusion is that the motion of a landing gear moving in a straight line without fuselage elasticity is stable for a sufficiently large rearward position of the wheel behind the swivel axis, and this conclusion is well verified quantitatively by the experimental data.

  13. Dither Helps Compensate For Friction In Reaction Wheel

    NASA Technical Reports Server (NTRS)

    Stetson, John B., Jr.

    1994-01-01

    Dither control and generator unit incorporated into reaction-wheel attitude-control system to help compensate for error caused by friction in reaction-wheel bearings at and near zero speed of wheel. Reaction-wheel attitude-control system designed primarily to maintain desired orientation of spacecraft but also useful in maintaining desired orientation of terrestrial antenna, optical instrument, or other device on aircraft, ship, land vehicle, or other moving platform. Alternating torque sufficient to overcome static friction applied at low speed.

  14. EAST AND NORTH SIDES OF BLOWER HOUSE SHOWING POWER WHEELS ...

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

    EAST AND NORTH SIDES OF BLOWER HOUSE SHOWING POWER WHEELS AND RACEWAY, LOOKING SOUTH. - Tannehill Furnace, 12632 Confederate Parkway, Tannehill Historical State Park, Bucksville, Tuscaloosa County, AL

  15. Off-the-road four-wheel drive vehicle

    SciTech Connect

    Foote, D.C.; Grinde, J.E.

    1987-03-17

    An off-road recreational vehicle is described comprising, in combination: (a) a frame; (b) front and rear pairs of wheels, each having relatively wide, ultra-low pressure tires mounted thereon, each of the wheel being secured to an axle member; (c) a limited slip differential means including a drive input disposed between the axle members of the front pair of wheels; (d) driving means drivenly connected to the axle members of the rear pair of wheels; (e) means for independently suspending the frame relative to the axle members of the front pair of wheels and for resiliently securing the frame to the driving means connected to the axle members of the rear pair of wheels; (f) an engine supported on the frame between the front and rear pairs of wheels, the engine having an output shaft directly coupled to the drive means connected to the rear axle member; and (g) over-running clutch means operatively coupled to the output shaft of the engine and interposed between the output shaft of the engine and the drive input of the limited slip differential for applying a driving force to the front pair of wheels only when slipage exists between the rear pair of wheels and the ground.

  16. Development and Validation of Reaction Wheel Disturbance Models: Empirical Model

    NASA Astrophysics Data System (ADS)

    Masterson, R. A.; Miller, D. W.; Grogan, R. L.

    2002-01-01

    Accurate disturbance models are necessary to predict the effects of vibrations on the performance of precision space-based telescopes, such as the Space Interferometry Mission (SIM). There are many possible disturbance sources on such spacecraft, but mechanical jitter from the reaction wheel assembly (RWA) is anticipated to be the largest. A method has been developed and implemented in the form of a MATLAB toolbox to extract parameters for an empirical disturbance model from RWA micro-vibration data. The disturbance model is based on one that was used to predict the vibration behaviour of the Hubble Space Telescope (HST) wheels and assumes that RWA disturbances consist of discrete harmonics of the wheel speed with amplitudes proportional to the wheel speed squared. The MATLAB toolbox allows the extension of this empirical disturbance model for application to any reaction wheel given steady state vibration data. The toolbox functions are useful for analyzing RWA vibration data, and the model provides a good estimate of the disturbances over most wheel speeds. However, it is shown that the disturbances are under-predicted by a model of this form over some wheel speed ranges. The poor correlation is due to the fact that the empirical model does not account for disturbance amplifications caused by interactions between the harmonics and the structural modes of the wheel. Experimental data from an ITHACO Space Systems E-type reaction wheel are used to illustrate the model development and validation process.

  17. Social dominance rank influences wheel running behavior in mice.

    PubMed

    Vargas-Pérez, Héctor; Sellings, Laurie; Grieder, Taryn; Díaz, José-Luis

    2009-07-03

    Dominance hierarchies within social groups determine resource distribution. Resources, such as food and access to mating partners, can act as reinforcers. The present study examined the effect of social rank on access to wheel running-a reinforcing behavior performed by laboratory animals. Mice were identified as dominant or subordinate and given access to a running wheel access under solitary or social conditions. In the solitary condition, subordinate and dominant mice spent equal amounts of time on the running wheel. In the social condition, when one wheel was present, subordinate mice spent less time on the wheel than did dominant mice. Conversely, when two wheels were present, subordinates spent more time on the wheel than did dominant mice. When mice were given 24h access to one running wheel in the social condition, dominant mice ran more than subordinates during the dark cycle. Subordinate mice did not compensate for the lack of running wheel access by schedule shifting. These results suggest that social rank influences access to reinforcers by behavioral interference rather than by social inhibition.

  18. Wheel-slip Control Method for Seeking Maximum Value of Tangential Force between Wheel and Rail

    NASA Astrophysics Data System (ADS)

    Kondo, Keiichiro; Yasuoka, Ikuo; Yamazaki, Osamu; Toda, Shinichi; Nakazawa, Yosuke

    A method for reducing motor torque in proportion to wheel slip is applied to an inverter-driven electric locomotive. The motor torque at wheel-slip speed is less than the torque at the maximum tangential force or the adhesion force. A novel anti-slip control method for seeking the maximum value of the tangential force between the wheel and rail is proposed in this paper. The characteristics of the proposed method are analyzed theoretically to design the torque reduction ratio and the rate of change of the pattern between the wheel-slip speed and motor current. In addition, experimental tests are also carried out to verify that the use of the proposed method increases the traction force of an electric locomotive driven by induction motors and inverters. The experimental test results obtained by using the proposed control method are compared with the experimental results obtained by using a conventional control method. The averaged operational current when using the proposed control method is 10% more than that when using the conventional control method.

  19. Opportunity Rolls Free Again (Right Front Wheel)

    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 of the rover's right front wheel, taken by the front hazard-avoidance camera, make up this brief movie. It chronicles the challenge Opportunity faced to free itself from a ripple dubbed 'Jammerbugt.' The rover's 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 weathered its 'Jammerbugt' and is again on its way toward Victoria Crater.

  20. Opportunity Rolls Free Again (Left Front Wheel)

    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 of the rover's left front wheel, taken by the front hazard-avoidance camera, make up this brief movie. It chronicles the challenge Opportunity faced to free itself from a ripple dubbed 'Jammerbugt.' The rover's 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 weathered its 'Jammerbugt' and is again on its way toward Victoria Crater.

  1. Opportunity Rolls Free Again (Right Front Wheel)

    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 of the rover's right front wheel, taken by the front hazard-avoidance camera, make up this brief movie. It chronicles the challenge Opportunity faced to free itself from a ripple dubbed 'Jammerbugt.' The rover's 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 weathered its 'Jammerbugt' and is again on its way toward Victoria Crater.

  2. Opportunity Rolls Free Again (Left Front Wheel)

    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 of the rover's left front wheel, taken by the front hazard-avoidance camera, make up this brief movie. It chronicles the challenge Opportunity faced to free itself from a ripple dubbed 'Jammerbugt.' The rover's 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 weathered its 'Jammerbugt' and is again on its way toward Victoria Crater.

  3. 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.

  4. 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.

  5. 15. Photocopied June 1978. WHEEL HOUSE RUINS OF 'NEW' FURNACE. ...

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

    15. Photocopied June 1978. WHEEL HOUSE RUINS OF 'NEW' FURNACE. SEGMENT GEAR REMNANTS VISIBLE STANDING IN WHEEL PIT IN FOREGROUND. SOURCE: MCINTYRE DEVELOPMENT, NL INDUSTRIES, TAHAWUS, N.Y. - Adirondack Iron & Steel Company, New Furnace, Hudson River, Tahawus, Essex County, NY

  6. 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.

  7. 6. DETAIL VIEW OF FLUTTER WHEEL IN BASEMENT OF GRISTMILL. ...

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

    6. DETAIL VIEW OF FLUTTER WHEEL IN BASEMENT OF GRISTMILL. THE RECTANGULAR ENCLOSED FLUME PROTRUDING FROM THE WALL AT CENTER/LEFT CARRIED WATER FROM THE EQUALIZING VAT THAT POWERED THE WHEEL - San Jose Grist Mill, Southwest of San Jose Drive, east of Espada Road, San Antonio, Bexar County, TX

  8. 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.

  9. 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…

  10. 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...

  11. 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...

  12. 47. DETAIL OF ORIGINAL VANE ASSEMBLY AND TWO WHEEL SECTIONS ...

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

    47. DETAIL OF ORIGINAL VANE ASSEMBLY AND TWO WHEEL SECTIONS FROM ELI WINDMILLS, THE VANE SHEET BEARING STENCILED PAINTED INSCRIPTION, 'KREGEL WINDMILL CO. ELI NEBRASKA CITY, NEB.' VISIBLE IN THE IMAGE ARE BOTH SIDES OF THE WHEEL SECTIONS, SHOWING THE METHOD OF BLADE MOUNTING FOR ELI WINDMILLS. - Kregel Windmill Company Factory, 1416 Central Avenue, Nebraska City, Otoe County, NE

  13. Design and Optimization of a Magnetic Wheel for Hull Climbing

    DTIC Science & Technology

    2013-09-01

    diameter (OD), 36 0.25-inch OD by 1-inch long N52 Neodymium magnets, and 0.125-inch-thick flux-plates. The wheel weighed 1.22 pounds and provided an... Neodymium magnets, and 0.125-inch thick flux- plates. The wheel weighed 1.22 pounds and provided an attractive force of 21 lbf. naval visit, board

  14. 16 CFR 1512.11 - Requirements for wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS REQUIREMENTS FOR BICYCLES Regulations § 1512.11 Requirements for wheels. (a) Spokes. There shall be no missing spokes. (b) Alignment. The wheel assembly shall be aligned such that no less than 1.6... rotated to any position. (c) Rims. Rims shall retain the spokes and tire when side-loaded with 2000 N (450...

  15. 13. VIEW OF PELTON WHEELS AND GENERATORS IN CAVITY PLANT, ...

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

    13. VIEW OF PELTON WHEELS AND GENERATORS IN CAVITY PLANT, AS SEEN FROM PELTON WHEEL-GENERATOR UNIT #1; GENERATOR #1, #2, #3, #4 WERE MANUFACTURED BY WESTINGHOUSE, EACH RATED AT 1,500 KW - Snoqualmie Falls Hydroelectric Project, .5 mile north of Snoqualmie, Snoqualmie, King County, WA

  16. 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…

  17. Spirit Wheels Digging into Soft Ground, Sol 1899

    NASA Image and Video Library

    2009-11-12

    Wheel slippage during attempts to extricate NASA Mars Rover Spirit from a patch of soft ground during the preceding two weeks had partially buried the wheels by the 1,899th Martian day, or sol, of the Spirit mission on Mars May 6, 2009.

  18. 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.

  19. 14 CFR 23.745 - Nose/tail wheel steering.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must be demonstrated that its use does not require exceptional pilot skill during takeoff and landing, in crosswinds...) Movement of the pilot's steering control must not interfere with the retraction or extension of the...

  20. 14 CFR 23.745 - Nose/tail wheel steering.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Landing Gear § 23.745 Nose/tail wheel steering. (a) If nose/tail wheel steering is installed, it must be demonstrated that its use does not require exceptional pilot skill during takeoff and landing, in crosswinds...) Movement of the pilot's steering control must not interfere with the retraction or extension of the...

  1. 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.

  2. 18. Credit Pelton Water Wheel Company. View from the older ...

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

    18. Credit Pelton Water Wheel Company. View from the older portion of the powerhouse with the 750 kW 1901 generating units in the left foreground. An exciter unit and the switchboard are in the right foreground. (Pelton Water Wheel Company, Pelton Impulse & Reaction Turbine Installations, 1920, p. 33). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  3. Considering the Influence of Prerequisite Performance on Wheel Spinning

    ERIC Educational Resources Information Center

    Wan, Hao; Beck, Joseph Barbosa

    2015-01-01

    The phenomenon of wheel spinning refers to students attempting to solve problems on a particular skill, but becoming stuck due to an inability to learn the skill. Past research has found that students who do not master a skill quickly tend not to master it at all. One question is why do students wheel spin? A plausible hypothesis is that students…

  4. Kinematics, dynamics, and control of omnidirectional vehicles with mecanum wheels

    SciTech Connect

    Wampfler, G.; Salecker, M.; Wittenburg, J. )

    1989-01-01

    Vehicles equipped with so-called mecanum wheels can translate in any direction and rotate on the spot without slippage though the axes of the wheels are fixed in the vehicle body. This paper presents an analysis of the kinematics, dynamics, and control of such vehicles.

  5. 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.

  6. Cryogenic ratchet wheel drive for the ISOPHOT experiment

    NASA Astrophysics Data System (ADS)

    Kulzer, G.; Lemke, D.; Bauer, H.; Bellemann, H.; Neumann, G.

    An advanced cryogenic ratchet wheel drive has been developed based on experience from the GIRL project. Power dissipation, microphony, lifetime and positioning accuracy have been significantly improved. Three of these wheels equipped with filters, apertures and mirrors compose the core of the photometer experiment for ISO.

  7. Experiments on the resistance of airplane wheels and radiators

    NASA Technical Reports Server (NTRS)

    1924-01-01

    Experiments were made on the resistance of four airplane wheels of different sizes and coverings and two Lamblin radiators. The results show the important influence of the wheel coverings. The closing of a shutter, which was fitted to one of the radiators, considerably lessened the resistance.

  8. 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…

  9. 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...

  10. 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...

  11. 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...

  12. 14 CFR 27.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false One-wheel landing conditions. 27.483... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  13. 14 CFR 29.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false One-wheel landing conditions. 29.483... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  14. 14 CFR 29.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false One-wheel landing conditions. 29.483... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  15. 14 CFR 29.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false One-wheel landing conditions. 29.483... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  16. 14 CFR 27.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false One-wheel landing conditions. 27.483... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  17. 14 CFR 27.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false One-wheel landing conditions. 27.483... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  18. 14 CFR 29.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false One-wheel landing conditions. 29.483... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  19. 14 CFR 27.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false One-wheel landing conditions. 27.483... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  20. 14 CFR 27.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false One-wheel landing conditions. 27.483... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  1. 14 CFR 29.483 - One-wheel landing conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the level attitude and to contact the ground on one aft wheel. In this attitude— (a) The vertical load... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false One-wheel landing conditions. 29.483... AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads §...

  2. 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.

  3. 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.

  4. Camber Angle Inspection for Vehicle Wheel Alignments

    PubMed Central

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-01-01

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ±0.015∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi. PMID:28165365

  5. Longitudinal wheel slip during ABS braking

    NASA Astrophysics Data System (ADS)

    Hartikainen, Lassi; Petry, Frank; Westermann, Stephan

    2015-02-01

    Anti-lock braking system (ABS) braking tests with two subcompact passenger cars were performed on dry and wet asphalt, as well as on snow and ice surfaces. The operating conditions of the tyres in terms of wheel slip were evaluated using histograms of the wheel slip data. The results showed different average slip levels for different road surfaces. It was also found that changes in the tyre tread stiffness affected the slip operating range through a modification of the slip value at which the maximum longitudinal force is achieved. Variation of the tyre footprint length through modifications in the inflation pressure affected the slip operating range as well. Differences in the slip distribution between vehicles with different brake controllers were also observed. The changes in slip operating range in turn modified the relative local sliding speeds between the tyre and the road. The results highlight the importance of the ABS controller's ability to adapt to changing slip-force characteristics of tyres and provide estimates of the magnitude of the effects of different tyre and road operating conditions.

  6. Camber Angle Inspection for Vehicle Wheel Alignments.

    PubMed

    Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan

    2017-02-03

    This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.

  7. Fatigue Properties of Cast Magnesium Wheels

    NASA Astrophysics Data System (ADS)

    Li, Zhenming; Luo, Alan A.; Wang, Qigui; Peng, Liming; Zhang, Peng

    2016-08-01

    This paper investigates the fatigue properties and deformation behavior of a newly developed Mg-2.96Nd-0.21Zn-0.39Zr magnesium alloy wheel in both as-cast and T6 conditions. Compared with the as-cast alloy, the T6-treated alloy shows a significant increase in fatigue strength and cyclic stress amplitude. This is believed to be attributed to the change of defect type from porosity to oxides and the increased matrix strength in the T6 (peak-aged) condition. For the as-cast alloy wheel, fatigue failure mainly originated from the cast defects including porosity, oxide film, and inclusion at or near the sample surface. In the T6-treated alloy, however, oxides and inclusions or slip bands initiate the fatigue cracks. Solution treatment appears to reduce or eliminate the shrinkage porosity because of grain growth and dissolution of as-cast eutectic phases in the grain boundaries. The cyclic stress amplitude of the as-cast alloy increases with increasing the number of cycles, while the T6-treated alloy shows cyclic softening after the stress reaches a maximum value. The Coffin-Manson law and Basquin equation can be used to evaluate the life of low cycle fatigue. The developed long crack model and multi-scale fatigue (MSF) models can be used to predict high-cycle fatigue life of the Mg-2.96Nd-0.21Zn-0.39Zr alloys with or without casting defects.

  8. A fully omnidirectional wheeled assembly for robotic vehicles

    SciTech Connect

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

    1990-06-01

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

  9. Porous metal-organic truncated octahedron constructed from paddle-wheel squares and terthiophene links.

    PubMed

    Ni, Zheng; Yassar, Abderrahim; Antoun, Tarek; Yaghi, Omar M

    2005-09-21

    A metal-organic truncated octahedron (termed MOP-28) has been constructed from six rigid square-shaped Cu2(CO2)4 paddle-wheel building units and twelve 2,2':5',2' '-terthiophene-5,5' '-dicarboxylate (TTDC) linkers. TTDC linker in the cis,cis conformation provides the critical 90 degrees linkage for this unique construction. The porous structure of MOP-28 is maintained even after the removal of guest species, as evidenced by this compound's nitrogen sorption isotherm of Type I characteristics and unprecedented surface area (Langmuir surface area 1100 m2/g, BET surface area 914 m2/g) among materials composed of discrete molecules.

  10. Independent wheel suspension system using thrust bearing constant velocity universal drive joints as suspension members to minimize wheel chamber

    SciTech Connect

    Krude, W.

    1986-12-30

    An independent wheel suspension system is described for a vehicle having an engine adapted to provide a driving torque, a chassis, vehicle support means for resiliently supporting the chassis for displacement relative to a driving surface, and a wheel assembly for each wheel having a vertical center plane through the center thereof and a wheel axis substantially perpendicular to the vertical center plane. The wheel assembly has a chamber angle relative to the vertical center plane adapted to undergo a change of chamber as the wheel assembly undergoes movement relative to the vertical center plane. The independent wheel suspension system comprises: differential means comprising a differential housing, a differential input at an engine end of the differential housing adapted to be coupled to the engine so as to receive the driving torque therefrom about a differential input axis. The differential housing has a pair of lateral sides on opposite sides of the differential input axis, each lateral side having a differential output axis therethrough. The differential means is adapted to redirect the driving torque from the differential input axis to the differential output axis and is supported by the vehicle support means to position the differential input axis substantially perpendicular to the wheel axis.

  11. A Wheeled Mobile Device for Deployment of Surface and Subsurface Instruments and for Subsurface Sampling on Planets

    NASA Astrophysics Data System (ADS)

    Richter, L.; Bernasconi, M.; Haapanala, S.; Steiner, R.; Coste, P.

    2003-04-01

    shifting the center-of-mass, should the vehicle fall on its side. All wheels and the two folding levers are individually driven by brushless DC motors located inside a thermal enclosure in the vehicle cab. Except for the actuators and drive mechanisms, the enclosure houses a central electronics unit which also provides pre-processing of payload data. For the power supply and communications, a tether link to the lander is used, allowing a maximum range of some 20 m. As to the tether type, a flexible printed circuit was chosen which allows efficient packaging of the tether on board the vehicle. The wheel design was based on theoretical and experimental studies on tractive performance of small wheels on planetary soils being one of the subjects of the MIDD activity, involving a dedicated soil channel at DLR. As a result, the vehicle wheels were chosen to be rigid while featuring a wire mesh running surface and chevron-shaped grousers. Mass of a flight unit is projected to be around 2.9 kg, excluding the vehicle payload. The principal design philosophy for MIDD has been: conservative design with sufficient margins (i.e., provision of thermal enclosure for instruments); early component development and realistic environmental testing (mechanism functional testing in Thermal Vacuum; dust sealing test with mechanisms operating in simulated airborne dust environment of Mars).

  12. Falling chains

    NASA Astrophysics Data System (ADS)

    Wong, Chun Wa; Yasui, Kosuke

    2006-06-01

    The one-dimensional fall of a folded chain with one end suspended from a rigid support and a chain falling from a resting heap on a table is studied. Because their Lagrangians contain no explicit time dependence, the falling chains are conservative systems. Their equations of motion are shown to contain a term that enforces energy conservation when masses are transferred between subchains. We show that Cayley's 1857 energy nonconserving solution for a chain falling from a resting heap is incorrect because it neglects the energy gained when a link leaves a subchain. The maximum chain tension measured by Calkin and March for the falling folded chain is given a simple if rough interpretation. Other aspects of the falling folded chain are briefly discussed.

  13. Molecule concept nanocars: chassis, wheels, and motors?

    PubMed

    Joachim, Christian; Rapenne, Gwénael

    2013-01-22

    The design, synthesis, and running of a molecular nanovehicle on a surface assisted by proper nanocommunication channels for feeding and guiding the vehicle now constitute an active field of research and are no longer a nano-joke. In this Perspective, we describe how this field began, its growth, and problems to be solved. Better molecular wheels, a molecular motor with its own gears assembling for torque transmission must be mounted on (i.e., chemically bonded to) a good molecular chassis for the resulting covalently constructed molecular nanovehicle to run on a surface in a controlled manner at the atomic scale. We propose a yearly molecule concept nanocar contest to boost molecular nanovehicle research.

  14. 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.

  15. Martian Sand Disturbed by Rover Wheel

    NASA Image and Video Library

    2015-12-10

    This view shows grains of sand where NASA's Curiosity Mars rover was driven into a shallow sand sheet near a large dune. The disturbance by the wheel exposed interior material of the sand body, including finer sand grains than on the undisturbed surface. Sunlight is coming from the left. The scene covers an area 1.3 inches by 1.0 inch (3.3 by 2.5 centimeters). This is a focus-merge product from Curiosity's Mars Hand Lens Imager (MAHLI), combining multiple images taken at different focus settings to yield sharper focus at varying distances from the lens. The component images were taken on Dec. 3, 2015, during the 1,182nd Martian day, or sol, of Curiosity's work on Mars. http://photojournal.jpl.nasa.gov/catalog/PIA20170

  16. Rover's Wheel Churns Up Bright Martian Soil

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel.

    The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life.

    Spirit acquired this mosaic with the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. The view presented here is an approximately true-color rendering.

  17. Rover's Wheel Churns Up Bright Martian Soil

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA's Mars Exploration Rover Spirit acquired this mosaic on the mission's 1,202nd Martian day, or sol (May 21, 2007), while investigating the area east of the elevated plateau known as 'Home Plate' in the 'Columbia Hills.' The mosaic shows an area of disturbed soil, nicknamed 'Gertrude Weise' by scientists, made by Spirit's stuck right front wheel.

    The trench exposed a patch of nearly pure silica, with the composition of opal. It could have come from either a hot-spring environment or an environment called a fumarole, in which acidic, volcanic steam rises through cracks. Either way, its formation involved water, and on Earth, both of these types of settings teem with microbial life.

    Spirit acquired this mosaic with the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters. The view presented here is an approximately true-color rendering.

  18. 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.

  19. Neuromuscular performance characteristics of open-wheel and rally drivers.

    PubMed

    Backman, Jani; Häkkinen, Keijo; Ylinen, Jari; Häkkinen, Arja; Kyröläinen, Heikki

    2005-11-01

    The purpose of the present study was to investigate neuromuscular performance characteristics in open-wheel and rally drivers using the cross-sectional study design. The subjects (N = 28) consisted of experienced international-level open-wheel drivers (n = 9), experienced international-level rally drivers (n = 9) and a physically active nondriving male control group (n = 10). In 3 separate test sessions, speed, muscle strength, and endurance tests were performed. The rally drivers had higher (p < 0.05) grip, shoulder flexion, and ankle plantar flexion strength, as compared to the control group. The open-wheel drivers showed higher strengths (p < 0.05) than the controls in neck forces, grip, shoulder flexion, and leg extension. The rally drivers were stronger (p < 0.05) than the open-wheel drivers in grip, plantar flexion, and trunk extension forces, whereas the open-wheel drivers were stronger (p < 0.01) than the rally drivers in neck lateral flexions and extension forces. Thus, competitive long-term open-wheel and rally drivers differ specifically in neuromuscular performance. For practice, these findings suggest that rally drivers should concentrate on training hand, ankle, and trunk muscles, whereas open-wheel drivers should train neck muscles, especially, and all other muscle groups rather equally.

  20. Power transfer device for four-wheel drive vehicle

    SciTech Connect

    Hayashi, H.

    1986-10-21

    A power transfer device is described for a four-wheel drive vehicle having a transmission drivingly connected to a prime mover of the vehicle and having a set of front road wheels and a set of rear road wheels adapted to be driven from the transmission. The transfer device comprises: a first differential of the bevel gear type including a differential case arranged to be applied with drive torque from the transmission, a pinion gear rotatably mounted within the differential case, and a pair or side gears rotatably mounted within the differential case and in mesh with the pinion gear; a first output shaft connected to one of the side gears for driving the front or rear road wheels; a second output shaft connected to the other side gear for driving the rear or front road wheels; a second differential of the planetary gear type including a differential carrier formed to contain the differential case therein; and a selector mechanism arranged to selectively provide a drive connection between the second output shaft and the rear or front road wheels or a drive connection between the differential carrier and the rear or front road wheels.