Laminar boundary layer response to rotation of a finite diameter surface patch

International Nuclear Information System (INIS)

Klewicki, J.C.; Hill, R.B.

2003-01-01

The responses of the flat plate laminar boundary layer to perturbations generated by rotating a finite patch of the bounding surface are explored experimentally. The size of the surface patch was of the same order as the boundary layer thickness. The displacement thickness Reynolds number range of the boundary layers explored was 72-527. The rotation rates of the surface patch ranged from 2.14 to 62.8 s-1. Qualitative flow visualizations and quantitative molecular tagging velocimetry measurements revealed that rotation of a finite surface patch generates an asymmetric loop-like vortex. Significant features of this vortex include that, (i) the sign of the vorticity in the vortex head is opposite that of the boundary layer vorticity regardless of the sign of the input rotation, (ii) one leg of the vortex exhibits motion akin to solid body rotation while the other leg is best characterized as a spanwise shear layer, (iii) the vortex leg exhibiting near solid body rotation lifts more rapidly from the surface than the leg more like a shear layer, and (iv) the vortex leg exhibiting near solid body rotation always occurs on the side of the surface patch experiencing downstream motion. These asymmetries switch sides depending on the sign of the input rotation. The present results are interpreted and discussed relative to analytical solutions for infinite geometries. By way of analogy, plausible connections are drawn between the present results and the influences of wall normal vortices in turbulent boundary layer flows

Vibration-rotational overtones absorption of solid hydrogens using optoacoustic spectroscopy technique

International Nuclear Information System (INIS)

Vieira, M.M.F.

1985-01-01

Vibrational-rotational overtones absorption solid hydrogens (H 2 , D 2 , HD) is studied using pulsed laser piezoeletric transducer (PULPIT) optoacoustic spectroscopy is studied. A general downward shift in energy from isolated molecular energies is observed. Studying normal-hydrogen it was observed that the phonon excitations associated with double-molecular transitions are predominantly transverse-optical phonons, whereas the excitations associated with single-molecular transitions are predominantly longitudinal - optical phonons. Multiplet structures were observed for certain double transitions in parahydrogen and orthodeuterium. The HD spectrum, besides presenting the sharp zero-phonon lines and the associated phonon side bands, like H 2 and D 2 , showed also two different features. This observation was common to all the transitions involving pure rotational excitation in H 2 and D 2 , which showed broad linewidths. This, together with some other facts (fluorescence lifetime *approx*10 5 sec; weak internal vibration and lattice coupling), led to the proposition of a mechanism for the fast nonradiative relaxation in solid hydrogens, implied from some observed experimental evidences. This relaxation, due to strong coupling, would happen in two steps: the internal vibration modes would relax to the rotational modes of the molecules, and then this rotational modes would relax to the lattice vibration modes. (Author) [pt

Nuclear shape evolution starting from superdeformed state. Role of two-body collision and rotation

International Nuclear Information System (INIS)

Liu, Yu-xin; Sakata, Fumihiko

1999-01-01

With the nuclear density distribution being simulated by the Boltzmann Uehling-Uhlenbeck equation and Vlasov equation with several rotational frequencies, the time evolution of the quadrupole moment of nucleus 86 Zr starting with superdeformed shape is studied. The contribution of two-body collisions and the effects of collective rotation to the shape evolution is investigated. The numerical results indicate that the two-body collisions play a role of damping on the evolution from a superdeformed shape to a normal deformed one in a case without rotation. In a case of rotation with lower frequency, the two-body collisions accelerate the evolution process. A new role of the collective rotation to enhance the nuclear fission is proposed. (author)

Chaotic Zones around Rotating Small Bodies

Energy Technology Data Exchange (ETDEWEB)

Lages, José; Shevchenko, Ivan I. [Institut UTINAM, Observatoire des Sciences de l’Univers THETA, CNRS, Université de Franche-Comté, Besançon F-25030 (France); Shepelyansky, Dima L., E-mail: jose.lages@utinam.cnrs.fr [Laboratoire de Physique Théorique du CNRS, IRSAMC, Université de Toulouse, UPS, Toulouse F-31062 (France)

2017-06-01

Small bodies of the solar system, like asteroids, trans-Neptunian objects, cometary nuclei, and planetary satellites, with diameters smaller than 1000 km usually have irregular shapes, often resembling dumb-bells or contact binaries. The spinning of such a gravitating dumb-bell creates around it a zone of chaotic orbits. We determine its extent analytically and numerically. We find that the chaotic zone swells significantly if the rotation rate is decreased; in particular, the zone swells more than twice if the rotation rate is decreased 10 times with respect to the “centrifugal breakup” threshold. We illustrate the properties of the chaotic orbital zones in examples of the global orbital dynamics about asteroid 243 Ida (which has a moon, Dactyl, orbiting near the edge of the chaotic zone) and asteroid 25143 Itokawa.

A lumped model for rotational modes in periodic solid composites

KAUST Repository

Peng, Pai; Asiri, Sharefa M.; Zhang, Xiujuan; Li, Yan; Wu, Ying

2013-01-01

We present a lumped model to study the rotational modes in a type of two-dimensional periodic solid composites comprised of a square array of rubber-coated steel cylinders embedded in an epoxy matrix. The model captures the physical essence of rotational modes in such systems for various combinations of material parameters, and, therefore it is able to describe the transition behaviour when the system is gradually adjusted from an elastic metamaterial to an elastic phononic crystal. From the model, we can define a transition zone which separates the typical elastic metamaterials and the phononic crystals.

A lumped model for rotational modes in periodic solid composites

KAUST Repository

Peng, Pai

2013-10-01

We present a lumped model to study the rotational modes in a type of two-dimensional periodic solid composites comprised of a square array of rubber-coated steel cylinders embedded in an epoxy matrix. The model captures the physical essence of rotational modes in such systems for various combinations of material parameters, and, therefore it is able to describe the transition behaviour when the system is gradually adjusted from an elastic metamaterial to an elastic phononic crystal. From the model, we can define a transition zone which separates the typical elastic metamaterials and the phononic crystals.

Geology and photometric variation of solar system bodies with minor atmospheres: implications for solid exoplanets.

Science.gov (United States)

Fujii, Yuka; Kimura, Jun; Dohm, James; Ohtake, Makiko

2014-09-01

A reasonable basis for future astronomical investigations of exoplanets lies in our best knowledge of the planets and satellites in the Solar System. Solar System bodies exhibit a wide variety of surface environments, even including potential habitable conditions beyond Earth, and it is essential to know how they can be characterized from outside the Solar System. In this study, we provide an overview of geological features of major Solar System solid bodies with minor atmospheres (i.e., the terrestrial Moon, Mercury, the Galilean moons, and Mars) that affect surface albedo at local to global scale, and we survey how they influence point-source photometry in the UV/visible/near IR (i.e., the reflection-dominant range). We simulate them based on recent mapping products and also compile observed light curves where available. We show a 5-50% peak-to-trough variation amplitude in one spin rotation associated with various geological processes including heterogeneous surface compositions due to igneous activities, interaction with surrounding energetic particles, and distribution of grained materials. Some indications of these processes are provided by the amplitude and wavelength dependence of variation in combinations of the time-averaged spectra. We also estimate the photometric precision needed to detect their spin rotation rates through periodogram analysis. Our survey illustrates realistic possibilities for inferring the detailed properties of solid exoplanets with future direct imaging observations. Key Words: Planetary environments-Planetary geology-Solar System-Extrasolar terrestrial planets.

Effects of asymmetrical stance and movement on body rotation in pushing.

Science.gov (United States)

Lee, Yun-Ju; Aruin, Alexander S

2015-01-21

Pushing objects in the presence of body asymmetries could increase the risk of back injury. Furthermore, when the object is heavy, it could exacerbate the effects induced by asymmetrical posture. We investigated how the use of asymmetrical posture and/or upper extremity movement affect vertical torque (Tz) and center of pressure (COP) displacement during pushing. Ten healthy volunteers were instructed to push objects of three different weights using two hands (symmetrical hand use) or one hand (asymmetrical hand use) while standing in symmetrical or asymmetrical foot-positions. The peak values of Tz and COP displacement in the medial-lateral direction (COPML) were analyzed. In cases of isolated asymmetry, changes in the Tz were mainly linked with effects of hand-use whereas effects of foot-position dominated changes in the COPML displacement. In cases of a combined asymmetry, the magnitudes of both Tz and COPML were additive when asymmetrical hand-use and foot-position induced the rotation of the lower and upper body in the same direction or subtractive when asymmetries resulted in the rotation of the body segments in the opposite directions. Moreover, larger Tz and COP displacements were seen when pushing the heavy weight. The results point out the importance of using Tz and COPML to describe the isolated or combined effects of asymmetrical upper extremity movement and asymmetrical posture on body rotation during pushing. Furthermore, it suggests that a proper combination of unilateral arm movement and foot placements could help to reduce body rotation even when pushing heavy objects. Copyright © 2014 Elsevier Ltd. All rights reserved.

Derivative Geometric Modeling of Basic Rotational Solids on CATIA

Institute of Scientific and Technical Information of China (English)

MENG Xiang-bao; PAN Zi-jian; ZHU Yu-xiang; LI Jun

2011-01-01

Hybrid models derived from rotational solids like cylinders, cones and spheres were implemented on CATIA software. Firstly, make the isosceles triangular prism, cuboid, cylinder, cone, sphere, and the prism with tangent conic and curved triangle ends, the cuboid with tangent cylindrical and curved rectangle ends, the cylinder with tangent spherical and curved circular ends as the basic Boolean deference units to the primary cylinders, cones and spheres on symmetrical and some critical geometric conditions, forming a series of variant solid models. Secondly, make the deference units above as the basic union units to the main cylinders, cones, and spheres accordingly, forming another set of solid models. Thirdly, make the tangent ends of union units into oblique conic, cylindrical, or with revolved triangular pyramid, quarterly cylinder and annulus ends on sketch based features to the main cylinders, cones, and spheres repeatedly, thus forming still another set of solid models. It is expected that these derivative models be beneficial both in the structure design, hybrid modeling, and finite element analysis of engineering components and in comprehensive training of spatial configuration of engineering graphics.

Behavior of a heavy cylinder in a horizontal cylindrical liquid-filled cavity at modulated rotation

International Nuclear Information System (INIS)

Kozlov, Nikolai V; Vlasova, Olga A

2016-01-01

The behavior of a heavy cylindrical solid in a horizontal cylindrical cavity is experimentally investigated. The cavity is filled with a viscous liquid and rotates. Two rotation regimes are considered. The first one is steady rotation. A number of body motion regimes are found depending on the cavity rotation speed. The second regime is a modulated rotation, in which the rotation speed is varying periodically. It can be presented as a sum of steady rotation and librations. On the whole, three different cases of the body repulsion from the cavity wall are observed. In the first case, the repulsion occurs when the body slides over a rotating cavity wall. In the second case, the body being in the centrifuged state—when it rotates with the fluid—detaches from the cavity wall under the action of gravity. In the third case, at librations, the wall performs oscillations and the body is repulsed from the wall due to the nonlinear viscous interaction with the fluid. (paper)

Equations of motion for free-flight systems of rotating-translating bodies

International Nuclear Information System (INIS)

Hodapp, A.E. Jr.

1976-09-01

General vector differential equations of motion are developed for a system of rotating-translating, unbalanced, constant mass bodies. Complete flexibility is provided in placement of the reference coordinates within the system of bodies and in placement of body fixed axes within each body. Example cases are presented to demonstrate the ease in reduction of these equations to the equations of motion for systems of interest

Vestibular-somatosensory interactions: effects of passive whole-body rotation on somatosensory detection.

Directory of Open Access Journals (Sweden)

Elisa Raffaella Ferrè

Full Text Available Vestibular signals are strongly integrated with information from several other sensory modalities. For example, vestibular stimulation was reported to improve tactile detection. However, this improvement could reflect either a multimodal interaction or an indirect interaction driven by vestibular effects on spatial attention and orienting. Here we investigate whether natural vestibular activation induced by passive whole-body rotation influences tactile detection. In particular, we assessed the ability to detect faint tactile stimuli to the fingertips of the left and right hand during spatially congruent or incongruent rotations. We found that passive whole-body rotations significantly enhanced sensitivity to faint shocks, without affecting response bias. Critically, this enhancement of somatosensory sensitivity did not depend on the spatial congruency between the direction of rotation and the hand stimulated. Thus, our results support a multimodal interaction, likely in brain areas receiving both vestibular and somatosensory signals.

Earth Rotation

Science.gov (United States)

Dickey, Jean O.

1995-01-01

The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

Tidal synchronization of an anelastic multi-layered body: Titan's synchronous rotation

Science.gov (United States)

Folonier, Hugo A.; Ferraz-Mello, Sylvio

2017-12-01

Tidal torque drives the rotational and orbital evolution of planet-satellite and star-exoplanet systems. This paper presents one analytical tidal theory for a viscoelastic multi-layered body with an arbitrary number of homogeneous layers. Starting with the static equilibrium figure, modified to include tide and differential rotation, and using the Newtonian creep approach, we find the dynamical equilibrium figure of the deformed body, which allows us to calculate the tidal potential and the forces acting on the tide generating body, as well as the rotation and orbital elements variations. In the particular case of the two-layer model, we study the tidal synchronization when the gravitational coupling and the friction in the interface between the layers is added. For high relaxation factors (low viscosity), the stationary solution of each layer is synchronous with the orbital mean motion ( n) when the orbit is circular, but the rotational frequencies increase if the orbital eccentricity increases. This behavior is characteristic in the classical Darwinian theories and in the homogeneous case of the creep tide theory. For low relaxation factors (high viscosity), as in planetary satellites, if friction remains low, each layer can be trapped in different spin-orbit resonances with frequencies n/2,n,3n/2,2n,\\ldots . When the friction increases, attractors with differential rotations are destroyed, surviving only commensurabilities in which core and shell have the same velocity of rotation. We apply the theory to Titan. The main results are: (i) the rotational constraint does not allow us to confirm or reject the existence of a subsurface ocean in Titan; and (ii) the crust-atmosphere exchange of angular momentum can be neglected. Using the rotation estimate based on Cassini's observation (Meriggiola et al. in Icarus 275:183-192, 2016), we limit the possible value of the shell relaxation factor, when a deep subsurface ocean is assumed, to γ _s≲ 10^{-9} s^{-1}, which

Mental rotation and the human body: Children's inflexible use of embodiment mirrors that of adults.

Science.gov (United States)

Krüger, Markus; Ebersbach, Mirjam

2017-12-25

Adults' mental rotation performance with body-like stimuli is enhanced if these stimuli are anatomically compatible with a human body, but decreased by anatomically incompatible stimuli. In this study, we investigated these effects for kindergartners and first-graders: When asked to mentally rotate cube configurations attached with human body parts in an anatomically compatible way, allowing for the projection of a human body, children performed better than with pure cube combinations. By contrast, when body parts were attached in an anatomically incompatible way, disallowing the projection of a human body, children performed worse than with pure combinations. This experiment is of specific interest against the background of two different theoretical approaches concerning imagery and the motor system in development: One approach assumes an increasing integration of motor processes and imagery over time that enables older children and adults to requisition motor resources for imagery processes, while the other postulates that imagery stems from early sensorimotor processes in the first place, and is disentangled from it over time. The finding that children of the two age groups tested show exactly the same effects as adults when mentally rotating anatomically compatible and incompatible stimuli is interpreted in favour of the latter approach. Statement of contribution What is already known on this subject? In mental rotation, adults perform better when rotating anatomically possible stimuli as compared to rotating standard cube combinations. Performance is worse when rotating anatomically impossible stimuli. What does this study add? The present study shows that children's mental transformations mirror those of adults in these respects. In case of the anatomically impossible stimuli, this highlights an inflexible use of embodiment in both age groups. This is in line with the Piagetian assumption of imagery being based on sensorimotor processes. © 2017 The British

Postural Effects on the Mental Rotation of Body-Related Pictures: An fMRI Study

Directory of Open Access Journals (Sweden)

Fangbing Qu

2018-05-01

Full Text Available This study investigated the embodied effects involved in the mental rotation of pictures of body parts (hands and feet. Blood oxygen level-dependent (BOLD signals were collected from 18 healthy volunteers who performed mental rotation tasks of rotated drawings of hands under different arm postures. Congruent drawings of hands (those congruent with left-hand posture evoked stronger activation in the left supplementary motor area (SMA, left precentral gyrus, and left superior parietal lobule (SPL than did incongruent drawings of hands. Congruent drawings of hands (those congruent with right-hand posture evoked significant activation in the left inferior parietal lobule (IPL, right SMA, bilateral middle frontal gyrus (MFG, left inferior frontal gyrus (IFG, and bilateral superior frontal gyrus (SFG compared to that evoked by the incongruent drawings of hands. Similar methodology was implemented with drawings of feet. However, no significant differences in brain activation were observed between congruent and incongruent drawings of feet. This finding suggests that body posture influences body part-related mental rotation in an effector-specific manner. A direct comparison between the medially and laterally rotated drawings revealed activation in the right IPL, left precentral gyrus, bilateral IFG, and bilateral SFG. These results suggest that biomechanical constraints affect the cognitive process of mental rotation.

Visuospatial memory computations during whole-body rotations in roll

NARCIS (Netherlands)

Pelt, S. van; Gisbergen, J.A.M. van; Medendorp, W.P.

2005-01-01

We used a memory-saccade task to test whether the location of a target, briefly presented before a whole-body rotation in roll, is stored in egocentric or in allocentric coordinates. To make this distinction, we exploited the fact that subjects, when tilted sideways in darkness, make systematic

Heat and water transfer in a rotating drum containing solid substrate particles

NARCIS (Netherlands)

Schutyser, M.A.I.; Weber, F.J.; Briels, W.J.; Rinzema, A.; Boom, R.M.

2003-01-01

In previous work we reported on the simulation of mixing behavior of a slowly rotating drum for solid-state fermentation (SSF) using a discrete particle model. In this investigation the discrete particle model is extended with heat and moisture transfer. Heat transfer is implemented in the model via

Structure and stability of rapidly rotating fluid bodies in general relativity. II. The structure of uniformly rotating pseudopolytropes

International Nuclear Information System (INIS)

Butterworth, E.M.

1976-01-01

A method is described for obtaining numerical solutions to the exact Einstein field equations that represent uniformly rotating perfect fluid bodies which are stationary and obey equations of state of the form (pressure) proportional (energy density) 1+1 //subn/. Sequences parametrized by the rate of rotation are generated for polytropic indices n between 0.5 and 3 and for varying strengths of relativity. All are found to terminate at surface velocities which are approximately 10 percent or more of the velocity of light. The configurations considered here are probably at least as relativistic as any stable astrophysical object in uniform rotation now thought to exist, but the phenomenon of an ergoregion appears in none of them and probably is absent in actual stars if magnetic viscosity or some other mechanism can induce rigid rotation

Rotation-limited growth of three-dimensional body-centered-cubic crystals.

Science.gov (United States)

Tarp, Jens M; Mathiesen, Joachim

2015-07-01

According to classical grain growth laws, grain growth is driven by the minimization of surface energy and will continue until a single grain prevails. These laws do not take into account the lattice anisotropy and the details of the microscopic rearrangement of mass between grains. Here we consider coarsening of body-centered-cubic polycrystalline materials in three dimensions using the phase field crystal model. We observe, as a function of the quenching depth, a crossover between a state where grain rotation halts and the growth stagnates and a state where grains coarsen rapidly by coalescence through rotation and alignment of the lattices of neighboring grains. We show that the grain rotation per volume change of a grain follows a power law with an exponent of -1.25. The scaling exponent is consistent with theoretical considerations based on the conservation of dislocations.

The role of rotation in the evolution of massive stars losing mass

International Nuclear Information System (INIS)

Sreenivasan, S.R.; Wilson, W.J.F.

1979-01-01

The role of differential and solid body rotation in the evolution of massive stars undergoing mass loss is discussed. The implications for Of, WR, β Cephei stars and shell stars are brought out. (Auth.)

Student understanding of the application of Newton's second law to rotating rigid bodies

Science.gov (United States)

Close, Hunter G.; Gomez, Luanna S.; Heron, Paula R. L.

2013-06-01

We report on an investigation of student understanding of rigid body dynamics in which we asked students in introductory calculus-based physics to compare the translational motions of identical rigid bodies subject to forces that differed only in the point of contact at which they were applied. There was a widespread tendency to claim that forces that cause rotational motion have a diminished effect on translational motion. A series of related problems was developed to examine whether similar errors would be made in other contexts, and interviews were conducted to probe student thinking in greater depth. In this paper, we describe the results of our investigation and also describe a series of different interventions that culminated in the development of a tutorial that improves student ability to apply Newton's second law to rotating rigid bodies.

Three-body interactions and the elastic constants of hcp solid 4He

Science.gov (United States)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-09-01

The effect of three-body interactions on the elastic properties of hexagonal close packed solid 4He is investigated using variational path integral (VPI) Monte Carlo simulations. The solid's nonzero elastic constants are calculated, at T = 0 K and for a range of molar volumes from 7.88 cm3/mol to 20.78 cm3/mol, from the bulk modulus and the three pure shear constants C0, C66, and C44. Three-body interactions are accounted for using our recently reported perturbative treatment based on the nonadditive three-body potential of Cencek et al. Previous studies have attempted to account for the effect of three-body interactions on the elastic properties of solid 4He; however, these calculations have treated zero point motions using either the Einstein or Debye approximations, which are insufficient in the molar volume range where solid 4He is characterized as a quantum solid. Our VPI calculations allow for a more accurate treatment of the zero point motions which include atomic correlation. From these calculations, we find that agreement with the experimental bulk modulus is significantly improved when three-body interactions are considered. In addition, three-body interactions result in non-negligible differences in the calculated pure shear constants and nonzero elastic constants, particularly at higher densities, where differences of up to 26.5% are observed when three-body interactions are included. We compare to the available experimental data and find that our results are generally in as good or better agreement with experiment as previous theoretical investigations.

On unsteady two-phase fluid flow due to eccentric rotation of a disk

Directory of Open Access Journals (Sweden)

A. K. Ghosh

2003-01-01

in a double-disk configuration, a result which is the reverse to that of solid-body rotation. Finally, the results are presented graphically to determine the quantitative response of the particle on the flow.

Numerical Simulation and Experiment of a Lifting Body with Leading-Edge Rotating Cylinder

OpenAIRE

A. Badarudin; C. S. Oon; S. N. Kazi; N. Nik-Ghazali; Y. J. Lee; W. T. Chong

2013-01-01

An experimental and simulation flight test has been carried out to evaluate the longitudinal gliding characteristics of a lifting body with blunted half-cone geometry. The novelty here is the lifting body's pitch control mechanism, which consists of a pair of leading-edge rotating cylinders. Flight simulation uses aerodynamic data from computational fluid dynamics supported by wind-tunnel test. Flight test consists of releasing an aluminum lifting body model from a moving vehicle at the appro...

Rotational Failure of Rubble-pile Bodies: Influences of Shear and Cohesive Strengths

Science.gov (United States)

Zhang, Yun; Richardson, Derek C.; Barnouin, Olivier S.; Michel, Patrick; Schwartz, Stephen R.; Ballouz, Ronald-Louis

2018-04-01

The shear and cohesive strengths of a rubble-pile asteroid could influence the critical spin at which the body fails and its subsequent evolution. We present results using a soft-sphere discrete element method to explore the mechanical properties and dynamical behaviors of self-gravitating rubble piles experiencing increasing rotational centrifugal forces. A comprehensive contact model incorporating translational and rotational friction and van der Waals cohesive interactions is developed to simulate rubble-pile asteroids. It is observed that the critical spin depends strongly on both the frictional and cohesive forces between particles in contact; however, the failure behaviors only show dependence on the cohesive force. As cohesion increases, the deformation of the simulated body prior to disruption is diminished, the disruption process is more abrupt, and the component size of the fissioned material is increased. When the cohesive strength is high enough, the body can disaggregate into similar-size fragments, which could be a plausible mechanism to form asteroid pairs or active asteroids. The size distribution and velocity dispersion of the fragments in high-cohesion simulations show similarities to the disintegrating asteroid P/2013 R3, indicating that this asteroid may possess comparable cohesion in its structure and experience rotational fission in a similar manner. Additionally, we propose a method for estimating a rubble pile’s friction angle and bulk cohesion from spin-up numerical experiments, which provides the opportunity for making quantitative comparisons with continuum theory. The results show that the present technique has great potential for predicting the behaviors and estimating the material strengths of cohesive rubble-pile asteroids.

Frozen orientation disorder and rotation excitation in solid mixtures of methane and krypton (neutron diffraction experiments)

International Nuclear Information System (INIS)

Grondey, S.

1986-09-01

The effect of a statistical replacement of CH 4 molecules by Kr atoms on the rotational states in solid methane has been examined. Obviously the anisotropic molecular interaction (octopole-octopole interaction) is disturbed in a way analogous to magnetic systems with random internal fields. Inelastic neutron scattering experiments on solid mixtures (CH 4 ) 1-x Kr x with 0≤x≤0.35 have been carried out, and simple models have been developed to interpret the spectra. (orig./BHO)

Linearized stationary incompressible flow around rotating and translating bodies- Leray solution

Czech Academy of Sciences Publication Activity Database

Deuring, P.; Kračmar, S.; Nečasová, Šárka

2014-01-01

Roč. 7, č. 5 (2014), s. 967-979 ISSN 1937-1632 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : stationary Oseen problem * rotating body * Leray solution Subject RIV: BA - General Mathematics Impact factor: 0.567, year: 2014 http://www.aimsciences.org/journals/displayArticlesnew.jsp?paperID=9874

Three-dimensional simulation of grain mixing in three different rotating drum designs for solid-state fermentation

NARCIS (Netherlands)

Schutyser, M.A.I.; Weber, F.J.; Briels, W.J.; Boom, R.M.; Rinzema, A.

2002-01-01

A previously published two-dimensional discrete particle simulation model for radial mixing behavior of various slowly rotating drums for solid-state fermentation (SSF) has been extended to a three-dimensional model that also predicts axial mixing. Radial and axial mixing characteristics were

Muscle contributions to elbow joint rotational stiffness in preparation for sudden external arm perturbations.

Science.gov (United States)

Holmes, Michael W R; Keir, Peter J

2014-04-01

Understanding joint stiffness and stability is beneficial for assessing injury risk. The purpose of this study was to examine joint rotational stiffness for individual muscles contributing to elbow joint stability. Fifteen male participants maintained combinations of three body orientations (standing, supine, sitting) and three hand preloads (no load, solid tube, fluid filled tube) while a device imposed a sudden elbow extension. Elbow angle and activity from nine muscles were inputs to a biomechanical model to determine relative contributions to elbow joint rotational stiffness, reported as percent of total stiffness. A body orientation by preload interaction was evident for most muscles (Psafety.

Frame-dragging effect in the field of non rotating body due to unit gravimagnetic moment

Science.gov (United States)

Deriglazov, Alexei A.; Ramírez, Walberto Guzmán

2018-04-01

Nonminimal spin-gravity interaction through unit gravimagnetic moment leads to modified Mathisson-Papapetrou-Tulczyjew-Dixon equations with improved behavior in the ultrarelativistic limit. We present exact Hamiltonian of the resulting theory and compute an effective 1/c2-Hamiltonian and leading post-Newtonian corrections to the trajectory and spin. Gravimagnetic moment causes the same precession of spin S as a fictitious rotation of the central body with angular momentum J = M/m S. So the modified equations imply a number of qualitatively new effects, that could be used to test experimentally, whether a rotating body in general relativity has null or unit gravimagnetic moment.

Vestibuloocular reflex dynamics during high-frequency and high-acceleration rotations of the head on body in rhesus monkey.

Science.gov (United States)

Huterer, Marko; Cullen, Kathleen E

2002-07-01

For frequencies >10 Hz, the vestibuloocular reflex (VOR) has been primarily investigated during passive rotations of the head on the body in humans. These prior studies suggest that eye movements lag head movements, as predicted by a 7-ms delay in the VOR reflex pathways. However, Minor and colleagues recently applied whole-body rotations of frequencies unity (1.1 at 5 Hz vs. 1.2 at 25 Hz), and phase lag increased only slightly with frequency (from 2 degrees at 5 Hz to 11 degrees at 25 Hz, a marked contrast to the 63 degrees lag at 25 Hz predicted by a 7-ms VOR latency). Furthermore, VOR response dynamics were comparable in darkness and when viewing a target and did not vary with peak velocity. Although monkeys offered less resistance to the initial cycles of applied head motion, the gain and phase of the VOR did not vary for early versus late cycles, suggesting that an efference copy of the motor command to the neck musculature did not alter VOR response dynamics. In addition, VOR dynamics were also probed by applying transient head perturbations with much greater accelerations (peak acceleration >15,000 degrees /s(2)) than have been previously employed. The VOR latency was between 5 and 6 ms, and mean gain was close to unity for two of the three animals tested. A simple linear model well described the VOR responses elicited by sinusoidal and transient head on body rotations. We conclude that the VOR is compensatory over a wide frequency range in monkeys and has similar response dynamics during passive rotation of the head on body as during passive rotation of the whole body in space.

Meniscus Stability in Rotating Systems

Science.gov (United States)

Reichel, Yvonne; Dreyer, Michael

2013-11-01

In this study, the stability of free surfaces of fluid between two rotating coaxial, circular disks is examined. Radially mounted baffles are used to form menisci of equal size. To the center of the upper disk, a tube is connected in which a separate meniscus is formed. Assuming solid-body rotation and ignoring dynamic effects, it is observed that the free surfaces between the disks fail to remain stable once the rotation speed exceeds a critical value. In other words, Rayleigh-Taylor instability ensues when the capillary forces fail to balance centrifugal forces. Dimensionless critical rotation speeds are studied by means of the Surface Evolver via SE-FIT for varied number of baffles, the normalized distance between the disks, and the normalized central tube radius. Drop tower tests are performed to confirm some of the numerical results. The computation also reveals that there are different modes of instability as a function of the relevant parameters. This study was funded by the space agency of the German Aerospace Center with resources of the Federal Ministry of Economics and Technology on the basis of a resolution of the German Bundestag under grant number 50 RL 1320.

Magnetic fields produced by rotating symmetrical bodies with homogeneous surface charge density

International Nuclear Information System (INIS)

Espejel-Morales, R; Murguía-Romero, G; Calles, A; Cabrera-Bravo, E; Morán-López, J L

2016-01-01

We present a numerical calculation for the stationary magnetic field produced by different rotating bodies with homogeneous and constant surface charge density. The calculation is done by superposing the magnetic field produced by a set of loops of current which mimic the magnetic field produced by belts of current defined by slices of fixed width. We consider the cases of a sphere, ellipsoids, open and closed cylinders and a combination of these in a dumbbell -like shell. We also plot their magnetic field lines using a technique that make use of the Runge–Kutta fourth-order method. Up to our knowledge, the case of closed cylinders was not calculated before. In contrast to previous results, we find that the magnetic field inside finite hollow bodies is homogeneous only in the case of a sphere. This is consequence of the fact that, for the sphere, the surface of any slice taken perpendicularly to the rotation axis, depends only on its thickness, like in the case of an infinite cylinder. (paper)

One-dimensional analysis of the hydrodynamic and thermal characteristics of thin film flows including the hydraulic jump and rotation

Science.gov (United States)

Thomas, S.; Hankey, W.; Faghri, A.; Swanson, T.

1990-01-01

The flow of a thin liquid film with a free surface along a horizontal plane that emanates from a pressurized vessel is examined numerically. In one g, a hydraulic jump was predicted in both plane and radial flow, which could be forced away from the inlet by increasing the inlet Froude number or Reynolds number. In zero g, the hydraulic jump was not predicted. The effect of solid-body rotation for radial flow in one g was to 'wash out' the hydraulic jump and to decrease the film height on the disk. The liquid film heights under one g and zero g were equal under solid-body rotation because the effect of centrifugal force was much greater than that of the gravitational force. The heat transfer to a film on a rotating disk was predicted to be greater than that of a stationary disk because the liquid film is extremely thin and is moving with a very high velocity.

Oscillation measuring device for body of rotation

International Nuclear Information System (INIS)

Komita, Hideo.

1994-01-01

The present invention concerns an internal pump of a BWR type reactor and provides a device for detecting oscillations of a rotational shaft. Namely, recesses are formed along an identical circumference on the outer circumferential surface of the rotating portion each at a predetermined distance. The recesses rotate along with the rotation. An eddy current type displacement gage measures the distance to the outer circumferential surface of the rotating portion. The recesses are detected by the displacement gage as pulse signals. When the rotating portion oscillates, it is detected by the displacement gage as waveform signals. Accordingly, the output signals of the eddy current type displacement gage are formed by pulse signals superposed on the waveform signals. A rising detection circuit detects the rising position of the pulse signals as the components of the number of rotation of the rotating portion, and fall detection circuit detects the falling position. A comparator circuit is disposed in parallel with both of rising/falling detection circuits. A predetermined threshold value is set in the comparator circuit to output a signal when the inputted signal exceeds the value. (I.S.)

Many-body effects in X-ray photoemission spectroscopy and electronic properties of solids

International Nuclear Information System (INIS)

Kohiki, S.

1999-01-01

Photoemission from a solid is evidently a many-body process since the motion of each electron cannot be independent of the motions of other electrons. In this article we review the reported many-body effects in X-ray photoemission such as extra-atomic relaxation energy, charge transfer satellite and energy loss structure which are informative in relation to the characteristics of solids. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Dissociating object-based from egocentric transformations in mental body rotation: effect of stimuli size.

Science.gov (United States)

Habacha, Hamdi; Moreau, David; Jarraya, Mohamed; Lejeune-Poutrain, Laure; Molinaro, Corinne

2018-01-01

The effect of stimuli size on the mental rotation of abstract objects has been extensively investigated, yet its effect on the mental rotation of bodily stimuli remains largely unexplored. Depending on the experimental design, mentally rotating bodily stimuli can elicit object-based transformations, relying mainly on visual processes, or egocentric transformations, which typically involve embodied motor processes. The present study included two mental body rotation tasks requiring either a same-different or a laterality judgment, designed to elicit object-based or egocentric transformations, respectively. Our findings revealed shorter response times for large-sized stimuli than for small-sized stimuli only for greater angular disparities, suggesting that the more unfamiliar the orientations of the bodily stimuli, the more stimuli size affected mental processing. Importantly, when comparing size transformation times, results revealed different patterns of size transformation times as a function of angular disparity between object-based and egocentric transformations. This indicates that mental size transformation and mental rotation proceed differently depending on the mental rotation strategy used. These findings are discussed with respect to the different spatial manipulations involved during object-based and egocentric transformations.

Rates and timing of vertical-axis block rotations across the central Sierra Nevada-Walker Lane transition in the Bodie Hills, California/Nevada

Science.gov (United States)

Rood, Dylan H.; Burbank, Douglas W.; Herman, Scott W.; Bogue, Scott

2011-10-01

We use paleomagnetic data from Tertiary volcanic rocks to address the rates and timing of vertical-axis block rotations across the central Sierra Nevada-Walker Lane transition in the Bodie Hills, California/Nevada. Samples from the Upper Miocene (˜9 Ma) Eureka Valley Tuff suggest clockwise vertical-axis block rotations between NE-striking left-lateral faults in the Bridgeport and Mono Basins. Results in the Bodie Hills suggest clockwise rotations (R ± ΔR, 95% confidence limits) of 74 ± 8° since Early to Middle Miocene (˜12-20 Ma), 42 ± 11° since Late Miocene (˜8-9 Ma), and 14 ± 10° since Pliocene (˜3 Ma) time with no detectable northward translation. The data are compatible with a relatively steady rotation rate of 5 ± 2° Ma-1 (2σ) since the Middle Miocene over the three examined timescales. The average rotation rates have probably not varied by more than a factor of two over time spans equal to half of the total time interval. Our paleomagnetic data suggest that block rotations in the region of the Mina Deflection began prior to Late Miocene time (˜9 Ma), and perhaps since the Middle Miocene if rotation rates were relatively constant. Block rotation in the Bodie Hills is similar in age and long-term average rate to rotations in the Transverse Ranges of southern California associated with early transtensional dextral shear deformation. We speculate that the age of rotations in the Bodie Hills indicates dextral shear and strain accommodation within the central Walker Lane Belt resulting from coupling of the Pacific and North America plates.

Quasi-stationary gravitational collapse of slowly rotating bodies in general relativity

Energy Technology Data Exchange (ETDEWEB)

Miller, J C [Oxford Univ. (UK). Dept. of Astrophysics

1977-05-01

This paper presents results of quasi-stationary collapse calculations for a class of slowly rotating non-homogeneous bodies in general relativity. The results are qualitatively similar to those obtained previously for homogeneous models indicating that the effects described for the homogeneous models are likely to have some relevance for the gravitational collapse of real stars towards the black hole state. There is also a discussion of some basic questions associated with such calculations.

Molecular rotations and diffusion in solids, in particular hydrogen in metals

International Nuclear Information System (INIS)

Springer, T.

1977-01-01

The chapter deals mainly with problems related to physical chemistry. The author treats diffusion in solids, in particular of hydrogen in metals, and studies of molecular rotations, in particular studies of tunneling transitions which is a relatively new and rapidly developing field of high resolution neutron spectroscopy. Typical neutron spectra to be discussed appear in energy ranges of a few 10 -6 to a few 10 -3 eV, or 10 -5 to 10 -2 cm -1 . The discussion is restricted to scattering from the protons which is predominantly incoherent. This means that only the motions, or excitations, of individual protons or protonic groups are discussed, ignoring collective excitations and interference. (HPOE) [de

Propagation Velocity of Solid Earth Tides

Science.gov (United States)

Pathak, S.

2017-12-01

One of the significant considerations in most of the geodetic investigations is to take into account the outcome of Solid Earth tides on the location and its consequent impact on the time series of coordinates. In this research work, the propagation velocity resulting from the Solid Earth tides between the Indian stations is computed. Mean daily coordinates for the stations have been computed by applying static precise point positioning technique for a day. The computed coordinates are used as an input for computing the tidal displacements at the stations by Gravity method along three directions at 1-minute interval for 24 hours. Further the baseline distances are computed between four Indian stations. Computation of the propagation velocity for Solid Earth tides can be done by the virtue of study of the concurrent effect of it in-between the stations of identified baseline distance along with the time consumed by the tides for reaching from one station to another. The propagation velocity helps in distinguishing the impact at any station if the consequence at a known station for a specific time-period is known. Thus, with the knowledge of propagation velocity, the spatial and temporal effects of solid earth tides can be estimated with respect to a known station. As theoretically explained, the tides generated are due to the position of celestial bodies rotating about Earth. So the need of study is to observe the correlation of propagation velocity with the rotation speed of the Earth. The propagation velocity of Solid Earth tides comes out to be in the range of 440-470 m/s. This velocity comes out to be in a good agreement with the Earth's rotation speed.

Translational and rotational diffusion of dilute solid amorphous spherical nanocolloids by molecular dynamics simulation

Science.gov (United States)

Heyes, D. M.; Nuevo, M. J.; Morales, J. J.

Following on from our previous study (Heyes, D. M., Nuevo, M. J, and Morales, J. J., 1996, Molec. Phys., 88, 1503), molecular dynamics simulations have been carried out of translational and rotational diffusion of atomistically rough near-spherical solid Lennard-Jones (LJ) clusters immersed in a Weeks-Chandler-Andersen liquid solvent. A single cluster consisting of up to about 100LJ particles as part of an 8000 atom fluid system was considered in each case. The translational and rotational diffusion coefficients decrease with increasing cluster size and solvent density (roughly in proportion to the molar volume of the solvent). The simulations reveal that for clusters in excess of about 30LJ atoms there is a clear separation of timescales between angular velocity and orientation relaxation which adhere well to the small-step diffusion model encapsulated in Hubbard's relationship. For 100 atom clusters both the StokesEinstein (translation) and Stokes-Einstein-Debye (rotation) equations apply approximately. The small departures from these reference solutions indicate that the translational relaxation experiences a local viscosity in excess of the bulk value (typically by ~ 30%), whereas rotational relaxation experiences a smaller viscosity than the bulk (typically by ~ 30%) reasonably in accord with the Gierer-Wirtz model. Both of these observations are consistent with an observed layering of the liquid molecules next to the cluster observed in our previous study.

A conservative quaternion-based time integration algorithm for rigid body rotations with implicit constraints

DEFF Research Database (Denmark)

Nielsen, Martin Bjerre; Krenk, Steen

2012-01-01

A conservative time integration algorithm for rigid body rotations is presented in a purely algebraic form in terms of the four quaternions components and the four conjugate momentum variables via Hamilton’s equations. The introduction of an extended mass matrix leads to a symmetric set of eight...

Orbits on bodies of rotation

Science.gov (United States)

Schröer, H.

Orbits of small balls on revolutions solid shells are examined. Which velocity is necessary to stay in balance? The angular velocity remains constant. General revolution solid, revolution cone, revolution ellipsoid, ball, paraboloid and hyperboloid are treated. Chapter 1 represents the frictionless case. Chapter 2 deals with the friction case. The transformation from velocity to the belonging orbit height is calculated in chapter 3. In chapter 4 and 5 the macro revolution solids follow (without and with friction)is treated. The assumption of a homogeneous field is not possible here. The radial gravitational field must be used. In the last chapter we have orbits with non constant angular velocity that can be derived with the Lagrange-equations of the second kind in the frictionless case. Here is also possible to view different revolution solids. The book is recommended to all experimental-, theoretical and mathematical physicists. There is an english and a german edition.

A quasi-Bohmian approach for a homogeneous spherical solid body based on its geometric structure

International Nuclear Information System (INIS)

Koupaei, Jalaledin Yousefi; Golshani, Mehdi

2013-01-01

In this paper we express the space of rotation as a Riemannian space and try to generalize the classical equations of motion of a homogeneous spherical solid body in the domain of quantum mechanics. This is done within Bohm's view of quantum mechanics, but we do not use the Schrödinger equation. Instead, we assume that in addition to the classical potential there is an extra potential and try to obtain it. In doing this, we start from a classical picture based on Hamilton-Jacobi formalism and statistical mechanics but we use an interpretation which is different from the classical one. Then, we introduce a proper action and extremize it. This procedure gives us a mathematical identity for the extra potential that limits its form. The classical mechanics is a trivial solution of this method. In the simplest cases where the extra potential is not a constant, a mathematical identity determines it uniquely. In fact the first nontrivial potential, apart from some constant coefficients which are determined by experiment, is the usual Bohmian quantum potential

A rotating bluff-body disc for reduced variability in wind tunnel aerosol studies.

Science.gov (United States)

Koehler, Kirsten A; Anthony, T Renee; van Dyke, Michael; Volckens, John

2011-01-01

A rotating bluff-body disc (RBD) was developed to reduce spatiotemporal variability associated with sampling supermicron aerosol in low-velocity wind tunnels. The RBD is designed to rotate eight personal aerosol samplers around a circular path in a forward-facing plane aligned with the wind tunnel cross section. Rotation of the RBD allows each sampler to traverse an identical path about the wind tunnel cross section, which reduces the effects of spatial heterogeneity associated with dispersing supermicron aerosol in low-velocity wind tunnels. Samplers are positioned on the face of the RBD via sampling ports, which connect to an air manifold on the back of the disc. Flow through each sampler was controlled with a critical orifice or needle valve, allowing air to be drawn through the manifold with a single pump. A metal tube, attached to this manifold, serves as both the axis of rotation and the flow conduction path (between the samplers and the vacuum source). Validation of the RBD was performed with isokinetic samplers and 37-mm cassettes. For facing-the-wind tests, the rotation of the RBD significantly decreased intra-sampler variability when challenged with particle diameters from 1 to 100 μm. The RBD was then employed to determine the aspiration efficiency of Institute of Occupational Medicine (IOM) personal samplers under a facing-the-wind condition. Operation of IOM samplers on the RBD reduced the between-sampler variability for all particle sizes tested.

Rotational motion in nuclei

International Nuclear Information System (INIS)

Bohr, A.

1976-01-01

Nuclear structure theories are reviewed concerned with nuclei rotational motion. The development of the deformed nucleus model facilitated a discovery of rotational spectra of nuclei. Comprehensive verification of the rotational scheme and a successful classification of corresponding spectra stimulated investigations of the rotational movement dynamics. Values of nuclear moments of inertia proved to fall between two marginal values corresponding to rotation of a solid and hydrodynamic pattern of an unrotating flow, respectively. The discovery of governing role of the deformation and a degree of a symmetry violence for determining rotational degrees of freedon is pointed out to pave the way for generalization of the rotational spectra

Motion of a Rigid Body Supported at One Point by a Rotating Arm

Directory of Open Access Journals (Sweden)

Jeffrey D. Stoen

1993-01-01

Full Text Available This article details a scheme for evaluating the stability of motions of a system consisting of a rigid body connected at one point to a rotating arm. The nonlinear equations of motion for the system are formulated, and a method for finding exact solutions representing motions that resemble a state of rest is presented. The equations are then linearized and roots of the eigensystem are classified and used to construct stability diagrams that facilitate the assessment of effects of varying the body's mass properties and system geometry, changing the position of the attachment joint, and adding energy dissipation in the joint.

Understanding the Influence of Pressure and Radial Loads on Stress and Displacement Response of a Rotating Body: The Automobile Wheel

Directory of Open Access Journals (Sweden)

2006-01-01

Full Text Available This paper highlights the use of the finite element technique for analyzing stress and displacement distributions in wheels of automotive vehicles when subject to the conjoint influence of inflation pressure and radial load. The most commonly used considerations in the design of the rotating body are elucidated. A potentially viable technique for finite element modeling of radial wheel, subjected to loading, is highlighted. The extrinsic influence of inflation pressure on performance of the rotating body, that is, the wheel, is rationalized.

Dosimetric effects of rotational offsets in stereotactic body radiation therapy (SBRT) for lung cancer

Energy Technology Data Exchange (ETDEWEB)

Yang, Yun; Catalano, Suzanne; Kelsey, Chris R.; Yoo, David S.; Yin, Fang-Fang; Cai, Jing, E-mail: jing.cai@duke.edu

2014-04-01

To quantitatively evaluate dosimetric effects of rotational offsets in stereotactic body radiation therapy (SBRT) for lung cancer. Overall, 11 lung SBRT patients (8 female and 3 male; mean age: 75.0 years) with medially located tumors were included. Treatment plans with simulated rotational offsets of 1°, 3°, and 5° in roll, yaw, and pitch were generated and compared with the original plans. Both clockwise and counterclockwise rotations were investigated. The following dosimetric metrics were quantitatively evaluated: planning target volume coverage (PTV V{sub 100%}), max PTV dose (PTV D{sub max}), percentage prescription dose to 0.35 cc of cord (cord D{sub 0.35} {sub cc}), percentage prescription dose to 0.35 cc and 5 cc of esophagus (esophagus D{sub 0.35} {sub cc} and D{sub 5} {sub cc}), and volume of the lungs receiving at least 20 Gy (lung V{sub 20}). Statistical significance was tested using Wilcoxon signed rank test at the significance level of 0.05. Overall, small differences were found in all dosimetric matrices at all rotational offsets: 95.6% of differences were < 1% or < 1 Gy. Of all rotational offsets, largest change in PTV V{sub 100%}, PTV D{sub max}, cord D{sub 0.35} {sub cc}, esophagus D{sub 0.35} {sub cc}, esophagus D{sub 5} {sub cc}, and lung V{sub 20} was − 8.36%, − 6.06%, 11.96%, 8.66%, 6.02%, and − 0.69%, respectively. No significant correlation was found between any dosimetric change and tumor-to-cord/esophagus distances (R{sup 2} range: 0 to 0.44). Larger dosimetric changes and intersubject variations were observed at larger rotational offsets. Small dosimetric differences were found owing to rotational offsets up to 5° in lung SBRT for medially located tumors. Larger intersubject variations were observed at larger rotational offsets.

Laboratory tests of catastrophic disruption of rotating bodies

Science.gov (United States)

Morris, A. J. W.; Burchell, M. J.

2017-11-01

The results of catastrophic disruption experiments on static and rotating targets are reported. The experiments used cement spheres of diameter 10 cm as the targets. Impacts were by mm sized stainless steel spheres at speeds of between 1 and 7.75 km s-1. Energy densities (Q) in the targets ranged from 7 to 2613 J kg-1. The experiments covered both the cratering and catastrophic disruption regimes. For static, i.e. non-rotating targets the critical energy density for disruption (Q*, the value of Q when the largest surviving target fragment has a mass equal to one half of the pre-impact target mass) was Q* = 1447 ± 90 J kg-1. For rotating targets (median rotation frequency of 3.44 Hz) we found Q* = 987 ± 349 J kg-1, a reduction of 32% in the mean value. This lower value of Q* for rotating targets was also accompanied by a larger scatter on the data, hence the greater uncertainty. We suggest that in some cases the rotating targets behaved as static targets, i.e. broke up with the same catastrophic disruption threshold, but in other cases the rotation helped the break up causing a lower catastrophic disruption threshold, hence both the lower value of Q* and the larger scatter on the data. The fragment mass distributions after impact were similar in both the static and rotating target experiments with similar slopes.

Dosimetric effects of rotational offsets in stereotactic body radiation therapy (SBRT) for lung cancer

International Nuclear Information System (INIS)

Yang, Yun; Catalano, Suzanne; Kelsey, Chris R.; Yoo, David S.; Yin, Fang-Fang; Cai, Jing

2014-01-01

To quantitatively evaluate dosimetric effects of rotational offsets in stereotactic body radiation therapy (SBRT) for lung cancer. Overall, 11 lung SBRT patients (8 female and 3 male; mean age: 75.0 years) with medially located tumors were included. Treatment plans with simulated rotational offsets of 1°, 3°, and 5° in roll, yaw, and pitch were generated and compared with the original plans. Both clockwise and counterclockwise rotations were investigated. The following dosimetric metrics were quantitatively evaluated: planning target volume coverage (PTV V 100% ), max PTV dose (PTV D max ), percentage prescription dose to 0.35 cc of cord (cord D 0.35 cc ), percentage prescription dose to 0.35 cc and 5 cc of esophagus (esophagus D 0.35 cc and D 5 cc ), and volume of the lungs receiving at least 20 Gy (lung V 20 ). Statistical significance was tested using Wilcoxon signed rank test at the significance level of 0.05. Overall, small differences were found in all dosimetric matrices at all rotational offsets: 95.6% of differences were 100% , PTV D max , cord D 0.35 cc , esophagus D 0.35 cc , esophagus D 5 cc , and lung V 20 was − 8.36%, − 6.06%, 11.96%, 8.66%, 6.02%, and − 0.69%, respectively. No significant correlation was found between any dosimetric change and tumor-to-cord/esophagus distances (R 2 range: 0 to 0.44). Larger dosimetric changes and intersubject variations were observed at larger rotational offsets. Small dosimetric differences were found owing to rotational offsets up to 5° in lung SBRT for medially located tumors. Larger intersubject variations were observed at larger rotational offsets

A normal mode treatment of semi-diurnal body tides on an aspherical, rotating and anelastic Earth

Science.gov (United States)

Lau, Harriet C. P.; Yang, Hsin-Ying; Tromp, Jeroen; Mitrovica, Jerry X.; Latychev, Konstantin; Al-Attar, David

2015-08-01

Normal mode treatments of the Earth's body tide response were developed in the 1980s to account for the effects of Earth rotation, ellipticity, anelasticity and resonant excitation within the diurnal band. Recent space-geodetic measurements of the Earth's crustal displacement in response to luni-solar tidal forcings have revealed geographical variations that are indicative of aspherical deep mantle structure, thus providing a novel data set for constraining deep mantle elastic and density structure. In light of this, we make use of advances in seismic free oscillation literature to develop a new, generalized normal mode theory for the tidal response within the semi-diurnal and long-period tidal band. Our theory involves a perturbation method that permits an efficient calculation of the impact of aspherical structure on the tidal response. In addition, we introduce a normal mode treatment of anelasticity that is distinct from both earlier work in body tides and the approach adopted in free oscillation seismology. We present several simple numerical applications of the new theory. First, we compute the tidal response of a spherically symmetric, non-rotating, elastic and isotropic Earth model and demonstrate that our predictions match those based on standard Love number theory. Second, we compute perturbations to this response associated with mantle anelasticity and demonstrate that the usual set of seismic modes adopted for this purpose must be augmented by a family of relaxation modes to accurately capture the full effect of anelasticity on the body tide response. Finally, we explore aspherical effects including rotation and we benchmark results from several illustrative case studies of aspherical Earth structure against independent finite-volume numerical calculations of the semi-diurnal body tide response. These tests confirm the accuracy of the normal mode methodology to at least the level of numerical error in the finite-volume predictions. They also demonstrate

Does the athletes? body shape the athletes? mind? A few ideas on athletes? mental rotation performance. Commentary on Jansen and Lehmann

OpenAIRE

Heinen, Thomas

2013-01-01

Athletes exhibit differences in perceptual-cognitive abilities when compared to non-athletes. Recent theoretical developments focus on the role of the athletes? body in perceptual-cognitive tasks such as mental rotation tasks. It is assumed that the degree to which stimuli in mental rotation tasks can be embodied facilitates the mental rotation process. The implications of this assumption are discussed and ideas for future research are presented.

Perception of self motion during and after passive rotation of the body around an earth-vertical axis.

Science.gov (United States)

Sinha, N; Zaher, N; Shaikh, A G; Lasker, A G; Zee, D S; Tarnutzer, A A

2008-01-01

We investigated the perception of self-rotation using constant-velocity chair rotations. Subjects signalled self motion during three independent tasks (1) by pushing a button when rotation was first sensed, when velocity reached a peak, when velocity began to decrease, and when velocity reached zero, (2) by rotating a disc to match the perceived motion of the body, or (3) by changing the static position of the dial such that a bigger change in its position correlated with a larger perceived velocity. All three tasks gave a consistent quantitative measure of perceived angular velocity. We found a delay in the time at which peak velocity of self-rotation was perceived (2-5 s) relative to the beginning or to the end of chair rotation. In addition the decay of the perception of self-rotation was preceded by a sensed constant-velocity interval or plateau (9-14 s). This delay in the rise of self-motion perception, and the plateau for the maximum perceived velocity, contrasts with the rapid rise and the immediate decay of the angular vestibuloocular reflex (aVOR). This difference suggests that the sensory signal from the semicircular canals undergoes additional neural processing, beyond the contribution of the velocity-storage mechanism of the aVOR, to compute the percept of self-motion.

SU-E-J-165: Dosimetric Impact of Liver Rotations in Stereotactic Body Radiation Therapy

Energy Technology Data Exchange (ETDEWEB)

Pinnaduwage, D; Paulsson, A; Sudhyadhom, A; Chen, J; Chang, A; Anwar, M; Gottschalk, A; Yom, S S.; Descovich, M [University of California San Francisco, San Francisco, CA (United States)

2015-06-15

Purpose: Often in liver stereotactic body radiotherapy a single fiducial is implanted near the tumor for image-guided treatment delivery. In such cases, rotational corrections are calculated based on the spine. This study quantifies rotational differences between the spine and liver, and investigates the corresponding dosimetric impact. Methods: Seven patients with 3 intrahepatic fiducials and 4DCT scans were identified. The planning CT was separately co-registered with 4 phases of the 4DCT (0%, 50%, 100% inhale and 50% exhale) by 1) rigid registration of the spine, and 2) point-based registration of the 3 fiducials. Rotation vectors were calculated for each registration. Translational differences in fiducial positions between the 2 registrations methods were investigated. Dosimetric impact due to liver rotations and deformations was assessed using critical structures delineated on the 4DCT phases. For dose comparisons, a single fiducial was translationally aligned following spine alignment to represent what is typically done in the clinic. Results: On average, differences between spine and liver rotations during the 0%, 50%, 100% inhale, and 50% exhale phases were 3.23°, 3.27°, 2.26° and 3.11° (pitch), 3.00°, 2.24°, 3.12° and 1.73° (roll), and 1.57°, 1.98°, 2.09° and 1.36° (yaw), respectively. The maximum difference in rotations was 12°, with differences of >3° seen in 14/28 (pitch), 10/28 (roll), and 6/28 (yaw) cases. Average fiducial displacements of 2.73 (craniocaudal), 1.04 (lateral) and 1.82 mm (vertical) were seen. Evaluating percent dose differences for 5 patients at the peaks of the respiratory cycle, the maximum dose to the duodenum, stomach, bowel and esophagus differed on average by 11.4%, 5.3%, 11.2% and 49.1% between the 2 registration methods. Conclusion: Lack of accounting for liver rotation during treatment might Result in clinically significant dose differences to critical structures. Both rotational and translational deviations

A conserved quantity in thin body dynamics

Science.gov (United States)

Hanna, J. A.; Pendar, H.

2016-02-01

Thin, solid bodies with metric symmetries admit a restricted form of reparameterization invariance. Their dynamical equilibria include motions with both rigid and flowing aspects. On such configurations, a quantity is conserved along the intrinsic coordinate corresponding to the symmetry. As an example of its utility, this conserved quantity is combined with linear and angular momentum currents to construct solutions for the equilibria of a rotating, flowing string, for which it is akin to Bernoulli's constant.

Study of Particle Rotation Effect in Gas-Solid Flows using Direct Numerical Simulation with a Lattice Boltzmann Method

Energy Technology Data Exchange (ETDEWEB)

Kwon, Kyung [Tuskegee Univ., Tuskegee, AL (United States); Fan, Liang-Shih [The Ohio State Univ., Columbus, OH (United States); Zhou, Qiang [The Ohio State Univ., Columbus, OH (United States); Yang, Hui [The Ohio State Univ., Columbus, OH (United States)

2014-09-30

fluid is accelerated from rest by a constant average pressure gradient toward a steady Stokes flow. The simulation results agree well with the theories for the short- and long-time behavior of the drag force. Flows through non-rotational and rotational spheres in simple cubic arrays and random arrays are simulated over the entire range of packing fractions, and both low and moderate particle Reynolds numbers to compare the simulated results with the literature results and develop a new drag force formula, a new lift force formula, and a new torque formula. Random arrays of solid particles in fluids are generated with Monte Carlo procedure and Zinchenko's method to avoid crystallization of solid particles over high solid volume fractions. A new drag force formula was developed with extensive simulated results to be closely applicable to real processes over the entire range of packing fractions and both low and moderate particle Reynolds numbers. The simulation results indicate that the drag force is barely affected by rotational Reynolds numbers. Drag force is basically unchanged as the angle of the rotating axis varies.

The dynamic behavior of bacterial macrofibers growing with one end prevented from rotating: variation in shaft rotation along the fiber's length, and supercoil movement on a solid surface toward the constrained end

Directory of Open Access Journals (Sweden)

Chen Liling

2003-08-01

Full Text Available Abstract Background Bacterial macrofibers twist as they grow, writhe, supercoil and wind up into plectonemic structures (helical forms the individual filaments of which cannot be taken apart without unwinding that eventually carry loops at both of their ends. Terminal loops rotate about the axis of a fiber's shaft in contrary directions at increasing rate as the shaft elongates. Theory suggests that rotation rates should vary linearly along the length of a fiber ranging from maxima at the loop ends to zero at an intermediate point. Blocking rotation at one end of a fiber should lead to a single gradient: zero at the blocked end to maximum at the free end. We tested this conclusion by measuring directly the rotation at various distances along fiber length from the blocked end. The movement of supercoils over a solid surface was also measured in tethered macrofibers. Results Macrofibers that hung down from a floating wire inserted through a terminal loop grew vertically and produced small plectonemic structures by supercoiling along their length. Using these as markers for shaft rotation we observed a uniform gradient of initial rotation rates with slopes of 25.6°/min. mm. and 36.2°/min. mm. in two different fibers. Measurements of the distal tip rotation in a third fiber as a function of length showed increases proportional to increases in length with constant of proportionality 79.2 rad/mm. Another fiber tethered to the floor grew horizontally with a length-doubling time of 74 min, made contact periodically with the floor and supercoiled repeatedly. The supercoils moved over the floor toward the tether at approximately 0.06 mm/min, 4 times faster than the fiber growth rate. Over a period of 800 minutes the fiber grew to 23 mm in length and was entirely retracted back to the tether by a process involving 29 supercoils. Conclusions The rate at which growing bacterial macrofibers rotated about the axis of the fiber shaft measured at various

Four-body interaction energy for compressed solid krypton from quantum theory.

Science.gov (United States)

Tian, Chunling; Wu, Na; Liu, Fusheng; Saxena, Surendra K; Zheng, Xingrong

2012-07-28

The importance of the four-body contribution in compressed solid krypton was first evaluated using the many-body expansion method and the coupled cluster theory with full single and double excitations plus perturbative treatment of triples. All different four-atom clusters existing in the first- and second-nearest neighbor shells of face-centered cubic krypton were considered, and both self-consistent-field Hartree-Fock and correlation parts of the four-body interaction were accurately determined from the ambient conditions up to eightfold volume compression. We find that the four-body interaction energy is negative at compression ratio lower than 2, where the dispersive forces play a dominant role. With increasing the compression, the four-body contribution becomes repulsive and significantly cancels the over-softening effects of the three-body potential. The obtained equation of state (EOS) was compared with the experiments and the density-functional theory calculations. It shows that combination of the four-body effects with two- and three-body interactions leads to an excellent agreement with EOS measurements throughout the whole experimental range 0-130 GPa, and extends the prediction to 300 GPa.

TH-A-9A-03: Dosimetric Effect of Rotational Errors for Lung Stereotactic Body Radiotherapy

International Nuclear Information System (INIS)

Lee, J; Kim, H; Park, J; Kim, J; Kim, H; Ye, S

2014-01-01

Purpose: To evaluate the dosimetric effects on target volume and organs at risk (OARs) due to roll rotational errors in treatment setup of stereotactic body radiation therapy (SBRT) for lung cancer. Methods: There were a total of 23 volumetric modulated arc therapy (VMAT) plans for lung SBRT examined in this retrospective study. Each CT image of VMAT plans was intentionally rotated by ±1°, ±2°, and ±3° to simulate roll rotational setup errors. The axis of rotation was set at the center of T-spine. The target volume and OARs in the rotated CT images were re-defined by deformable registration of original contours. The dose distributions on each set of rotated images were re-calculated to cover the planning target volume (PTV) with the prescription dose before and after the couch translational correction. The dose-volumetric changes of PTVs and spinal cords were analyzed. Results: The differences in D95% of PTVs by −3°, −2°, −1°, 1°, 2°, and 3° roll rotations before the couch translational correction were on average −11.3±11.4%, −5.46±7.24%, −1.11±1.38% −3.34±3.97%, −9.64±10.3%, and −16.3±14.7%, respectively. After the couch translational correction, those values were −0.195±0.544%, −0.159±0.391%, −0.188±0.262%, −0.310±0.270%, −0.407±0.331%, and −0.433±0.401%, respectively. The maximum dose difference of spinal cord among the 23 plans even after the couch translational correction was 25.9% at −3° rotation. Conclusions: Roll rotational setup errors in lung SBRT significantly influenced the coverage of target volume using VMAT technique. This could be in part compensated by the translational couch correction. However, in spite of the translational correction, the delivered doses to the spinal cord could be more than the calculated doses. Therefore if rotational setup errors exist during lung SBRT using VMAT technique, the rotational correction would rather be considered to prevent over-irradiation of normal

Lumped model for rotational modes in phononic crystals

KAUST Repository

Peng, Pai

2012-10-16

We present a lumped model for the rotational modes induced by the rotational motion of individual scatterers in two-dimensional phononic crystals comprised of square arrays of solid cylindrical scatterers in solid hosts. The model provides a physical interpretation of the origin of the rotational modes, reveals the important role played by the rotational motion in determining the band structure, and reproduces the dispersion relations in a certain range. The model increases the possibilities of manipulating wave propagation in phononic crystals. In particular, expressions derived from the model for eigenfrequencies at high symmetry points unambiguously predict the presence of a new type of Dirac-like cone at the Brillouin center, which is found to be the result of accidental degeneracy of the rotational and dipolar modes.

Lumped model for rotational modes in phononic crystals

KAUST Repository

Peng, Pai; Mei, Jun; Wu, Ying

2012-01-01

We present a lumped model for the rotational modes induced by the rotational motion of individual scatterers in two-dimensional phononic crystals comprised of square arrays of solid cylindrical scatterers in solid hosts. The model provides a physical interpretation of the origin of the rotational modes, reveals the important role played by the rotational motion in determining the band structure, and reproduces the dispersion relations in a certain range. The model increases the possibilities of manipulating wave propagation in phononic crystals. In particular, expressions derived from the model for eigenfrequencies at high symmetry points unambiguously predict the presence of a new type of Dirac-like cone at the Brillouin center, which is found to be the result of accidental degeneracy of the rotational and dipolar modes.

Simulation of aerosol flow interaction with a solid body on molecular level

Science.gov (United States)

Amelyushkin, Ivan A.; Stasenko, Albert L.

2018-05-01

Physico-mathematical models and numerical algorithm of two-phase flow interaction with a solid body are developed. Results of droplet motion and its impingement upon a rough surface in real gas boundary layer simulation on the molecular level obtained via molecular dynamics technique are presented.

Generation of a rotating liquid liner by tangential injection

International Nuclear Information System (INIS)

Burton, R.L.; Turchi, P.J.; Jenkins, D.J.; Lanham, R.E.; Cameron, J.; Cooper, A.L.

1979-01-01

Efficient compression of low mass-density payloads by the implosion of higher mass-density liquid cylinders or liners, as in the NRL LINUS concept for controlled thermonuclear fusion, requires rotation of the liner material to avoid Rayleigh--Taylor instabilities at the liner-payload interface. Experimentally, such implosions have been demonstrated with liners formed within rotating implosion chambers. The present work uses a scale-model experimental apparatus to investigate the possibility of creating liner rotation by tangential injection of the liquid liner material. Different modes of behavior are obtained depending on the fluid exhaust procedures. Right-circular, cylindrical free surfaces are achieved with axial exhaust of fluid at radii interior to the injection nozzles, for which the liner exhibits a combination of solid-body and free vortex flows in different regions. Measurements allow estimates of power losses to viscous shear, turbulence, etc. A simple model based on open-channel flow is then derived, which is in good agreement with experiment, and is used to extrapolate results to the scale of a possible LINUS fusion reactor

A finite volume procedure for fluid flow, heat transfer and solid-body stress analysis

KAUST Repository

Jagad, P. I.

2018-04-12

A unified cell-centered unstructured mesh finite volume procedure is presented for fluid flow, heat transfer and solid-body stress analysis. An in-house procedure (A. W. Date, Solution of Transport Equations on Unstructured Meshes with Cell-Centered Colocated Variables. Part I: Discretization, International Journal of Heat and Mass Transfer, vol. 48 (6), 1117-1127, 2005) is extended to include the solid-body stress analysis. The transport terms for a cell-face are evaluated in a structured grid-like manner. The Cartesian gradients at the center of each cell-face are evaluated using the coordinate transformation relations. The accuracy of the procedure is demonstrated by solving several benchmark problems involving different boundary conditions, source terms, and types of loading.

Elastic and Viscoelastic Stresses of Nonlinear Rotating Functionally Graded Solid and Annular Disks with Gradually Varying Thickness

Directory of Open Access Journals (Sweden)

Allam M. N. M.

2017-12-01

Full Text Available Analytical and numerical nonlinear solutions for rotating variable-thickness functionally graded solid and annular disks with viscoelastic orthotropic material properties are presented by using the method of successive approximations.Variable material properties such as Young’s moduli, density and thickness of the disk, are first introduced to obtain the governing equation. As a second step, the method of successive approximations is proposed to get the nonlinear solution of the problem. In the third step, the method of effective moduli is deduced to reduce the problem to the corresponding one of a homogeneous but anisotropic material. The results of viscoelastic stresses and radial displacement are obtained for annular and solid disks of different profiles and graphically illustrated. The calculated results are compared and the effects due to many parameters are discussed.

Effect of octupole interaction on the rotational motion of rotors in a solid Kr-CD4 solution

International Nuclear Information System (INIS)

Dudkin, V V; Bagatskii, M I; Mashchenko, D A

2007-01-01

The heat capacity of solid (CD 4 ) n Kr 1-n solutions with CD 4 concentrations n = 0.09, 0.17, 0.25, 0.35 and solutions with n = 0.25 doped with 0.0005, 0.0021 and 0.0123 of O 2 impurity has been investigated at T 0.6-30 K. It is found that the molecular field responsible for a qualitative change in the rotational motion of the rotators increases sharply as the number of nearest neighbours increases from one to three. Below 1.6 K the temperature dependence of the heat capacities of the rotational subsystems of the solutions can be described by a sum of the contributions made by molecules finding themselves in effective weak, moderate and strong molecular fields. The average concentration and the effective energy differences between the ground and the first excited energy levels of the CD 4 molecules in the above mentioned fields have been estimated. It is shown that the considerable changes in the experimental heat capacities of the rotational subsystem normalized to a mole of rotors are mostly due to the changes in the relative concentrations x(n) of the rotors in these molecular fields. Above T = 0.6 K the nuclear-spin A, T and E species of the molecules reach equilibrium distribution within one measurement of the heat capacity. The O 2 impurity is found to produce great influence on the heat capacity of the rotational subsystem in the solution with n = 0.25 and the equilibrium composition of the nuclear-spin species of the molecules

Measurement of the translation and rotation of a sphere in fluid flow

Science.gov (United States)

Barros, Diogo; Hiltbrand, Ben; Longmire, Ellen K.

2018-06-01

The problem of determining the translation and rotation of a spherical particle moving in fluid flow is considered. Lagrangian tracking of markers printed over the surface of a sphere is employed to compute the center motion and the angular velocity of the solid body. The method initially calculates the sphere center from the 3D coordinates of the reconstructed markers, then finds the optimal rotation matrix that aligns a set of markers tracked at sequential time steps. The parameters involved in the experimental implementation of this procedure are discussed, and the associated uncertainty is estimated from numerical analysis. Finally, the proposed methodology is applied to characterize the motion of a large spherical particle released in a turbulent boundary layer developing in a water channel.

Compensations for increased rotational inertia during human cutting turns.

Science.gov (United States)

Qiao, Mu; Brown, Brian; Jindrich, Devin L

2014-02-01

Locomotion in a complex environment is often not steady state, but unsteady locomotion (stability and maneuverability) is not well understood. We investigated the strategies used by humans to perform sidestep cutting turns when running. Previous studies have argued that because humans have small yaw rotational moments of inertia relative to body mass, deceleratory forces in the initial velocity direction that occur during the turning step, or 'braking' forces, could function to prevent body over-rotation during turns. We tested this hypothesis by increasing body rotational inertia and testing whether braking forces during stance decreased. We recorded ground reaction force and body kinematics from seven participants performing 45 deg sidestep cutting turns and straight running at five levels of body rotational inertia, with increases up to fourfold. Contrary to our prediction, braking forces remained consistent at different rotational inertias, facilitated by anticipatory changes to body rotational speed. Increasing inertia revealed that the opposing effects of several turning parameters, including rotation due to symmetrical anterior-posterior forces, result in a system that can compensate for fourfold changes in rotational inertia with less than 50% changes to rotational velocity. These results suggest that in submaximal effort turning, legged systems may be robust to changes in morphological parameters, and that compensations can involve relatively minor adjustments between steps to change initial stance conditions.

The various contributions in Venus rotation rate and LOD

Science.gov (United States)

Cottereau, L.; Rambaux, N.; Lebonnois, S.; Souchay, J.

2011-07-01

Context. Thanks to the Venus Express Mission, new data on the properties of Venus could be obtained, in particular concerning its rotation. Aims: In view of these upcoming results, the purpose of this paper is to determine and compare the major physical processes influencing the rotation of Venus and, more particularly, the angular rotation rate. Methods: Applying models already used for Earth, the effect of the triaxiality of a rigid Venus on its period of rotation are computed. Then the variations of Venus rotation caused by the elasticity, the atmosphere, and the core of the planet are evaluated. Results: Although the largest irregularities in the rotation rate of the Earth on short time scales are caused by its atmosphere and elastic deformations, we show that the irregularities for Venus are dominated by the tidal torque exerted by the Sun on its solid body. Indeed, as Venus has a slow rotation, these effects have a large amplitude of two minutes of time (mn). These variations in the rotation rate are greater than the one induced by atmospheric wind variations that can reach 25-50 s of time (s), depending on the simulation used. The variations due to the core effects that vary with its size between 3 and 20 s are smaller. Compared to these effects, the influence of the elastic deformation caused by the zonal tidal potential is negligible. Conclusions: As the variations in the rotation of Venus reported here are close to 3 mn peak to peak, they should influence past, present, and future observations, thereby providing further constraints on the planet's internal structure and atmosphere.

The rotational elements of Mars and its satellites

Science.gov (United States)

Jacobson, R. A.; Konopliv, A. S.; Park, R. S.; Folkner, W. M.

2018-03-01

The International Astronomical Union (IAU) defines planet and satellite coordinate systems relative to their axis of rotation and the angle about that axis. The rotational elements of the bodies are the right ascension and declination of the rotation axis in the International Celestial Reference Frame and the rotation angle, W, measured easterly along the body's equator. The IAU specifies the location of the body's prime meridian by providing a value for W at epoch J2000. We provide new trigonometric series representations of the rotational elements of Mars and its satellites, Phobos and Deimos. The series for Mars are from a least squares fit to the rotation model used to orient the Martian gravity field. The series for the satellites are from a least squares fit to rotation models developed in accordance with IAU conventions from recent ephemerides.

A conserved quantity in thin body dynamics

International Nuclear Information System (INIS)

Hanna, J.A.; Pendar, H.

2016-01-01

Thin, solid bodies with metric symmetries admit a restricted form of reparameterization invariance. Their dynamical equilibria include motions with both rigid and flowing aspects. On such configurations, a quantity is conserved along the intrinsic coordinate corresponding to the symmetry. As an example of its utility, this conserved quantity is combined with linear and angular momentum currents to construct solutions for the equilibria of a rotating, flowing string, for which it is akin to Bernoulli's constant. - Highlights: • A conserved quantity relevant to the dynamical equilibria of thin structures. • A mixed Lagrangian–Eulerian non-material action principle for fixed windows of axially moving systems. • Analytical solutions for rotating, flowing strings (yarn balloons). • Noether meets Bernoulli in a textile factory.

A conserved quantity in thin body dynamics

Energy Technology Data Exchange (ETDEWEB)

Hanna, J.A., E-mail: hannaj@vt.edu [Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Department of Physics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Pendar, H. [Department of Biomedical Engineering and Mechanics, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)

2016-02-15

Thin, solid bodies with metric symmetries admit a restricted form of reparameterization invariance. Their dynamical equilibria include motions with both rigid and flowing aspects. On such configurations, a quantity is conserved along the intrinsic coordinate corresponding to the symmetry. As an example of its utility, this conserved quantity is combined with linear and angular momentum currents to construct solutions for the equilibria of a rotating, flowing string, for which it is akin to Bernoulli's constant. - Highlights: • A conserved quantity relevant to the dynamical equilibria of thin structures. • A mixed Lagrangian–Eulerian non-material action principle for fixed windows of axially moving systems. • Analytical solutions for rotating, flowing strings (yarn balloons). • Noether meets Bernoulli in a textile factory.

Model of the discrete destruction process of a solid body

Science.gov (United States)

Glagolev, V. V.; Markin, A. A.

2018-03-01

Destruction is considered as a discrete thermomechanical process, in which the deformation of a solid body is achieved by changing the boundary stresses acting on the part of the volume being destroyed with the external load unchanged. On the basis of the proposed concept, a model for adhesive stratification of a composite material is constructed. When adhesive stratification is used, the stress state of one or two boundaries of the adhesive layer changes to zero if the bonds with the joined body are broken. As a result of the stratification, the interaction between the part of the composite, which may include an adhesive layer and the rest of the body stops. When solving the elastoplastic problem of cohesive stratification, the region in which the destruction criterion is achieved is identified. With the help of a repeated solution of the problem of subcritical deformation with the known law of motion of the boundary of the region, the distribution of the load (nodal forces) acting from the region to the body is located. The next step considers the change in the stress–strain state of the body in the process of destruction of the selected area. The elastoplastic problem is solved with a simple unloading of the formed surface of the body and preservation of the external load corresponding to the beginning of the process of destruction.

Angular momentum transfer in primordial discs and the rotation of the first stars

Science.gov (United States)

Hirano, Shingo; Bromm, Volker

2018-05-01

We investigate the rotation velocity of the first stars by modelling the angular momentum transfer in the primordial accretion disc. Assessing the impact of magnetic braking, we consider the transition in angular momentum transport mode at the Alfvén radius, from the dynamically dominated free-fall accretion to the magnetically dominated solid-body one. The accreting protostar at the centre of the primordial star-forming cloud rotates with close to breakup speed in the case without magnetic fields. Considering a physically motivated model for small-scale turbulent dynamo amplification, we find that stellar rotation speed quickly declines if a large fraction of the initial turbulent energy is converted to magnetic energy (≳ 0.14). Alternatively, if the dynamo process were inefficient, for amplification due to flux freezing, stars would become slow rotators if the pre-galactic magnetic field strength is above a critical value, ≃10-8.2 G, evaluated at a scale of nH = 1 cm-3, which is significantly higher than plausible cosmological seed values (˜10-15 G). Because of the rapid decline of the stellar rotational speed over a narrow range in model parameters, the first stars encounter a bimodal fate: rapid rotation at almost the breakup level, or the near absence of any rotation.

Motion of rectangular prismatic bodies

International Nuclear Information System (INIS)

Poreh, M.; Wray, R.N.

1979-01-01

Rectangular prismatic bodies can assume either a translatory or an auto-rotating mode of motion during free motion in the atmosphere. The translatory mode is stable only when the dimensionless moment of inertia of the bodies is large, however, large perturbations will always start auto-rotation. The characteristics of the auto-rotational mode are shown to depend primarily on the aspect ratio of the bodies which determines the dimensionless rotational speed and the lift coefficient. Both the average drag and lift-coefficients of auto-rotating bodies are estimated, but it is shown that secondary effects make it impossible to determine their exact trajectories in atmospheric flows

Effect of Cold Stress on Fruiting Body Production by Medicinal Basidiomycetes in Submerged and Solid-phase Culture

Directory of Open Access Journals (Sweden)

E.P. Vetchinkina

2017-05-01

Full Text Available The ability of the medicinal xylotrophic basidiomycetes Lentinus edodes, Pleurotus ostreatus, Ganoderma lucidum and Grifola frondosa to produce typical and atypical fruiting bodies with viable basidiospores in submerged and solid-phase culture under stationary conditions in a beer wort-containing medium under cold stress was shown. The examined mushrooms, when not exposed to temperature stress, did not form fruiting bodies. In solid-phase culture in an agarized medium after cold treatment, the basidiome formation period was shortened by 1.5–2 times. Furthermore, the use of a mycelium subjected to temperature stress for inoculation induced and accelerated the formation of fruiting bodies on an industrial wood substrate, which is of great biotechnological importance.

Rotation of small clusters in sheared metallic glasses

International Nuclear Information System (INIS)

Delogu, Francesco

2011-01-01

Graphical abstract: When a Cu 50 Ti 50 metallic glass is shear-deformed, the irreversible rearrangement of local structures allows the rigid body rotation of clusters. Highlights: → A shear-deformed Cu 50 Ti 50 metallic glass was studied by molecular dynamics. → Atomic displacements occur at irreversible rearrangements of local structures. → The dynamics of such events includes the rigid body rotation of clusters. → Relatively large clusters can undergo two or more complete rotations. - Abstract: Molecular dynamics methods were used to simulate the response of a Cu 50 Ti 50 metallic glass to shear deformation. Attention was focused on the atomic displacements taking place during the irreversible rearrangement of local atomic structures. It is shown that the apparently disordered dynamics of such events hides the rigid body rotation of small clusters. Cluster rotation was investigated by evaluating rotation angle, axis and lifetimes. This permitted to point out that relatively large clusters can undergo two or more complete rotations.

A finite volume procedure for fluid flow, heat transfer and solid-body stress analysis

KAUST Repository

Jagad, P. I.; Puranik, B. P.; Date, A. W.

2018-01-01

A unified cell-centered unstructured mesh finite volume procedure is presented for fluid flow, heat transfer and solid-body stress analysis. An in-house procedure (A. W. Date, Solution of Transport Equations on Unstructured Meshes with Cell

Using rotating liquid bridges as accelerometers

Energy Technology Data Exchange (ETDEWEB)

Montanero, J.M. [Universidad de Extremadura, Badajoz (Spain). Dept. de Electronica e Ingenieria Electromecanica; Cabezas, G.; Acero, J.; Zayas, F.

1999-07-01

Liquid bridges have recently been proposed as fluid accelerometers that could be used to measure very small inertial forces under microgravity conditions [Meseguer et al., microgravity sci. technol. IX/2 (1996)]. The essential idea is to infer the values of such inertial forces from the liquid bridge interface contour, whose shape obviously depends on the values of such forces (apart from the bridge volume and the geometry of the supporting disks). Following a similar procedure, in this paper we explore the use of rotating axisymmetric liquid bridges to measure the residual axial gravity and the rotation rate of the liquid bridge regarded as a solid body. In light off the difficulties involved in performing experiments on Earth, the role of empirical data is played by an accurate numerical solution of the Young-Laplace equation. The values of both the axial gravity and angular speed are obtained by fitting the approximate analytical expressions derived in this paper to the numerical solution of the Young-Laplace equation. The comparison between the predicted and actual values of the variables of interest shows a satisfactory agreement, supporting the suitability of the procedure. (orig.)

Body fixed frame, rigid gauge rotations and large N random fields in QCD

International Nuclear Information System (INIS)

Levit, S.

1995-01-01

The ''body fixed frame'' with respect to local gauge transformations is introduced. Rigid gauge ''rotations'' in QCD and their Schroedinger equation are studied for static and dynamic quarks. Possible choices of the rigid gauge field configuration corresponding to a non-vanishing static colormagnetic field in the ''body fixed'' frame are discussed. A gauge invariant variational equation is derived in this frame. For large number N of colors the rigid gauge field configuration is regarded as random with maximally random probability distribution under constraints on macroscopic-like quantities. For the uniform magnetic field the joint probability distribution of the field components is determined by maximizing the appropriate entropy under the area law constraint for the Wilson loop. In the quark sector the gauge invariance requires the rigid gauge field configuration to appear not only as a background but also as inducing an instantaneous quark-quark interaction. Both are random in the large N limit. (orig.)

Conversion of the magnetic field measured in three components on the magnetic sensor body's random coordinate system into three components on geographical coordinate system through quaternion rotation.

Science.gov (United States)

LIM, M.; PARK, Y.; Jung, H.; SHIN, Y.; Rim, H.; PARK, C.

2017-12-01

To measure all components of a physical property, for example the magnetic field, is more useful than to measure its magnitude only in interpretation and application thereafter. To convert the physical property measured in 3 components on a random coordinate system, for example on moving magnetic sensor body's coordinate system, into 3 components on a fixed coordinate system, for example on geographical coordinate system, by the rotations of coordinate system around Euler angles for example, we should have the attitude values of the sensor body in time series, which could be acquired by an INS-GNSS system of which the axes are installed coincident with those of the sensor body. But if we want to install some magnetic sensors in array at sea floor but without attitude acquisition facility of the magnetic sensors and to monitor the variation of magnetic fields in time, we should have also some way to estimate the relation between the geographical coordinate system and each sensor body's coordinate system by comparison of the vectors only measured on both coordinate systems on the assumption that the directions of the measured magnetic field on both coordinate systems are the same. For that estimation, we have at least 3 ways. The first one is to calculate 3 Euler angles phi, theta, psi from the equation Vgeograph = Rx(phi) Ry(theta) Rz(psi) Vrandom, where Vgeograph is the vector on geographical coordinate system etc. and Rx(phi) is the rotation matrix around the x axis by the angle phi etc. The second one is to calculate the difference of inclination and declination between the 2 vectors on spherical coordinate system. The third one, used by us for this study, is to calculate the angle of rotation along a great circle around the rotation axis, and the direction of the rotation axis. We installed no. 1 and no. 2 FVM-400 fluxgate magnetometers in array near Cheongyang Geomagnetic Observatory (IAGA code CYG) and acquired time series of magnetic fields for CYG and for

Asymptotic structure of viscous incompressible flow around a rotating body, with nonvanishing flow field at infinity

Czech Academy of Sciences Publication Activity Database

Deuring, P.; Kračmar, S.; Nečasová, Šárka

2017-01-01

Roč. 68, č. 1 (2017), č. článku 16. ISSN 0044-2275 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : asymptotic profile * Pointwise decay * rotating body * stationary incompressible Navier–Stokes system Subject RIV: BA - General Mathematics OBOR OECD: Pure mathematics Impact factor: 1.687, year: 2016 http://link.springer.com/article/10.1007%2Fs00033-016-0760-x

Asymptotic structure of viscous incompressible flow around a rotating body, with nonvanishing flow field at infinity

Czech Academy of Sciences Publication Activity Database

Deuring, P.; Kračmar, S.; Nečasová, Šárka

2017-01-01

Roč. 68, č. 1 (2017), č. článku 16. ISSN 0044-2275 R&D Projects: GA ČR GA13-00522S Institutional support: RVO:67985840 Keywords : asymptotic profile * Pointwise decay * rotating body * stationary incompressible Navier–Stokes system Subject RIV: BA - General Math ematics OBOR OECD: Pure math ematics Impact factor: 1.687, year: 2016 http://link.springer.com/article/10.1007%2Fs00033-016-0760-x

Leonhard Euler and the mechanics of rigid bodies

Science.gov (United States)

Marquina, J. E.; Marquina, M. L.; Marquina, V.; Hernández-Gómez, J. J.

2017-01-01

In this work we present the original ideas and the construction of the rigid bodies theory realised by Leonhard Euler between 1738 and 1775. The number of treatises written by Euler on this subject is enormous, including the most notorious Scientia Navalis (1749), Decouverte d’un noveau principe de mecanique (1752), Du mouvement de rotation des corps solides autour d’un axe variable (1765), Theoria motus corporum solidorum seu rigidorum (1765) and Nova methodus motu corporum rigidorum determinandi (1776), in which he developed the ideas of the instantaneous rotation axis, the so-called Euler equations and angles, the components of what is now known as the inertia tensor, the principal axes of inertia, and, finally, the generalisation of the translation and rotation movement equations for any system. Euler, the man who ‘put most of mechanics into its modern form’ (Truesdell 1968 Essays in the History of Mechanics (Berlin: Springer) p 106).

Ultrafast rotation in an amphidynamic crystalline metal organic framework.

Science.gov (United States)

Vogelsberg, Cortnie S; Uribe-Romo, Fernando J; Lipton, Andrew S; Yang, Song; Houk, K N; Brown, Stuart; Garcia-Garibay, Miguel A

2017-12-26

Amphidynamic crystals are an emergent class of condensed phase matter designed with a combination of lattice-forming elements linked to components that display engineered dynamics in the solid state. Here, we address the design of a crystalline array of molecular rotors with inertial diffusional rotation at the nanoscale, characterized by the absence of steric or electronic barriers. We solved this challenge with 1,4-bicyclo[2.2.2]octane dicarboxylic acid (BODCA)-MOF, a metal-organic framework (MOF) built with a high-symmetry bicyclo[2.2.2]octane dicarboxylate linker in a Zn 4 O cubic lattice. Using spin-lattice relaxation 1 H solid-state NMR at 29.49 and 13.87 MHz in the temperature range of 2.3-80 K, we showed that internal rotation occurs in a potential with energy barriers of 0.185 kcal mol -1 These results were confirmed with 2 H solid-state NMR line-shape analysis and spin-lattice relaxation at 76.78 MHz obtained between 6 and 298 K, which, combined with molecular dynamics simulations, indicate that inertial diffusional rotation is characterized by a broad range of angular displacements with no residence time at any given site. The ambient temperature rotation of the bicyclo[2.2.2]octane (BCO) group in BODCA-MOF constitutes an example where engineered rotational dynamics in the solid state are as fast as they would be in a high-density gas or in a low-density liquid phase.

Effect of three-body interactions on the zero-temperature equation of state of HCP solid 4He

Science.gov (United States)

Barnes, Ashleigh L.; Hinde, Robert J.

2017-03-01

Previous studies have pointed to the importance of three-body interactions in high density 4He solids. However the computational cost often makes it unfeasible to incorporate these interactions into the simulation of large systems. We report the implementation and evaluation of a computationally efficient perturbative treatment of three-body interactions in hexagonal close packed solid 4He utilizing the recently developed nonadditive three-body potential of Cencek et al. This study represents the first application of the Cencek three-body potential to condensed phase 4He systems. Ground state energies from quantum Monte Carlo simulations, with either fully incorporated or perturbatively treated three-body interactions, are calculated in systems with molar volumes ranging from 21.3 cm3/mol down to 2.5 cm3/mol. These energies are used to derive the zero-temperature equation of state for comparison against existing experimental and theoretical data. The equations of state derived from both perturbative and fully incorporated three-body interactions are found to be in very good agreement with one another, and reproduce the experimental pressure-volume data with significantly better accuracy than is obtained when only two-body interactions are considered. At molar volumes below approximately 4.0 cm3/mol, neither two-body nor three-body equations of state are able to accurately reproduce the experimental pressure-volume data, suggesting that below this molar volume four-body and higher many-body interactions are becoming important.

Motions on a rotating planet

Science.gov (United States)

Schröer, H.

In chapter 1 we want to describe the motion of a falling body on a rotating planet. The planet rotates with an arbitrary changable angular velocity and has a translational acceleration. We obtain 3 differential equations. For the general gravitational field an exact solution is possible, when the differential equation system is explicit solvable. Then we consider the case, if the angular velocity and the translational acceleration is constant. With a special transformation we get 3 partial differential equations of first order. Instead of a planet sphere we can choose a general body of rotation. Even general bodies are possible. Chapter 2 contains the motion in a local coordinate system on planet's surface. We have an inhomogeneous linear differential equation of first order. If the angular velocity is constant, we get a system with constant coefficients. There is an english and a german edition.

Vortex Reconnection or Breakdown Subsequent to Perpendicular Collision With A Solid Body

Science.gov (United States)

Young, Larry A.

1999-01-01

This paper analytically examines the unsteady fluid dynamics of a vortex filament subsequent to a normal collision of the vortex with a solid body. In particular, the breakdown or reconnection phenomena, post-collision, for a vortex filament is studied. The paper does not investigate the collision dynamics process itself. The derived exact solution is based upon the laminar viscous form of the Helmholtz equations.

Influence of rotational setup error on tumor shift in bony anatomy matching measured with pulmonary point registration in stereotactic body radiotherapy for early lung cancer

International Nuclear Information System (INIS)

Suzuki, Osamu; Nishiyama, Kinji; Ueda, Yoshihiro; Miyazaki, Masayoshi; Tsujii, Katsutomo

2012-01-01

The objective of this study was to examine the correlation between the patient rotational error measured with pulmonary point registration and tumor shift after bony anatomy matching in stereotactic body radiotherapy for lung cancer. Twenty-six patients with lung cancer who underwent stereotactic body radiotherapy were the subjects. On 104 cone-beam computed tomography measurements performed prior to radiation delivery, rotational setup errors were measured with point registration using pulmonary structures. Translational registration using bony anatomy matching was done and the three-dimensional vector of tumor displacement was measured retrospectively. Correlation among the three-dimensional vector and rotational error and vertebra-tumor distance was investigated quantitatively. The median and maximum rotational errors of the roll, pitch and yaw were 0.8, 0.9 and 0.5, and 6.0, 4.5 and 2.5, respectively. Bony anatomy matching resulted in a 0.2-1.6 cm three-dimensional vector of tumor shift. The shift became larger as the vertebra-tumor distance increased. Multiple regression analysis for the three-dimensional vector indicated that in the case of bony anatomy matching, tumor shifts of 5 and 10 mm were expected for vertebra-tumor distances of 4.46 and 14.1 cm, respectively. Using pulmonary point registration, it was found that the rotational setup error influences the tumor shift. Bony anatomy matching is not appropriate for hypofractionated stereotactic body radiotherapy with a tight margin. (author)

On the Motion of solids in modified quantum mechanics

International Nuclear Information System (INIS)

Diosi, L.

1988-01-01

In this paper we apply the unified dynamics of Ghirardi, Rimini and Weber to the translational and rotational motion of solids in three dimensions. We show that, in a certain approximation, the rotational equations can formally be reduced to the translational ones already known. We point out that the rotation of solids as well as their translation are practically of classical nature without any observable quantum effects

The Effect of Rotation Stirring on Macrosegregation in Bi-Sn Alloy

Directory of Open Access Journals (Sweden)

Zulaida Yeni Muriani

2017-01-01

Full Text Available Macrosegregation is a defect that difficult to avoid in a metal alloy made by casting method. Macrosegregation can cause decreasing in mechanical properties of casting products. It will reduce their performance in industrial application. Macrosegregation is convinced occur during solidification time in liquid alloy. In the early solidified, The solids move upward/downward in liquid alloy during solidification are considered to contribute on macrosegregation formation. This movement occur due to the density differences between the solid and the surrounding liquid. This research want to observe the effect of stirring on macrosegregation formation for interfering on the movement of initial solidified solid. Stiring with rotation method is applied in this experiment at certain temperature. The temperature and the rotation speed of stirring are varied to observe the effect of rotation stirring on macrosegregation formation. The mold is covered by insulation jacket and kept the bottom part opened in order to obtain the directionally solidification. The result shows that the rotation stirring can change the macrostructure of casting but in case of composition distribution, the macrosegregation still appear. Increasing the rotation stirring will rise solid crystals up and the macrosegregation become more uniform and the treatment is better if conducting at lower temperature.

INTEGRATION OF THE ROTATION OF AN EARTH-LIKE BODY AS A PERTURBED SPHERICAL ROTOR

International Nuclear Information System (INIS)

Ferrer, Sebastian; Lara, Martin

2010-01-01

For rigid bodies close to a sphere, we propose an analytical solution that is free from elliptic integrals and functions, and can be fundamental for application to perturbed problems. After reordering the Hamiltonian as a perturbed spherical rotor, the Lie-series solution is generated up to an arbitrary order. Using the inertia parameters of different solar system bodies, the comparison of the approximate series solution with the exact analytical one shows that the precision reached with relatively low orders is at the same level of the observational accuracy for the Earth and Mars. Thus, for instance, the periodic errors of the mathematical solution are confined to the microarcsecond level with a simple second-order truncation for the Earth. On the contrary, higher orders are required for the mathematical solution to reach a precision at the expected level of accuracy of proposed new theories for the rotational dynamics of the Moon.

Mental rotation and working memory in musicians' dystonia.

Science.gov (United States)

Erro, Roberto; Hirschbichler, Stephanie T; Ricciardi, Lucia; Ryterska, Agata; Antelmi, Elena; Ganos, Christos; Cordivari, Carla; Tinazzi, Michele; Edwards, Mark J; Bhatia, Kailash P

2016-11-01

Mental rotation of body parts engages cortical-subcortical areas that are actually involved in the execution of a movement. Musicians' dystonia is a type of focal hand dystonia that is grouped together with writer's cramp under the rubric of "occupational dystonia", but it is unclear to which extent these two disorders share common pathophysiological mechanisms. Previous research has demonstrated patients with writer's cramp to have deficits in mental rotation of body parts. It is unknown whether patients with musicians' dystonia would display similar deficits, reinforcing the concept of shared pathophysiology. Eight patients with musicians' dystonia and eight healthy musicians matched for age, gender and musical education, performed a number of tasks assessing mental rotation of body parts and objects as well as verbal and spatial working memories abilities. There were no differences between patients and healthy musicians as to accuracy and reaction times in any of the tasks. Patients with musicians' dystonia have intact abilities in mentally rotating body parts, suggesting that this disorder relies on a highly selective disruption of movement planning and execution that manifests only upon playing a specific instrument. We further demonstrated that mental rotation of body parts and objects engages, at least partially, different cognitive networks. Copyright © 2016 Elsevier Inc. All rights reserved.

PRP as an Adjunct to Rotator Cuff Tendon Repair.

Science.gov (United States)

Barber, F Alan

2018-06-01

Arthroscopic rotator cuff repair is a commonly performed repair. Technical developments provide surgeons the tools to create biomechanically robust repairs. How can the biological response mirror the strong and stable surgery? Platelet-rich plasma (PRP) is a supraphysiological platelet concentration which may positively augment rotator cuff healing. Not all PRPs are the same. High leukocyte levels and thrombin activation may be detrimental to tendon healing. Thrombin activation triggers an immediate release of growth factors and may actually inhibit some parts of the healing response. Clear differences exist between liquid PRP (products released within hours after activation) and solid fibrin PRP which slowly releases factors over days. The heterogenicity data and grouping liquid and solid PRP together make systematic reviews confusing. Solid PRP fibrin constructs are often associated with increased tendon healing. PRP fibrin matrix offers the greatest promise for improving clinical success after rotator cuff tendon repair.

Rod rotation and differential rod contouring followed by direct vertebral rotation for treatment of adolescent idiopathic scoliosis: effect on thoracic and thoracolumbar or lumbar curves assessed with intraoperative computed tomography.

Science.gov (United States)

Seki, Shoji; Kawaguchi, Yoshiharu; Nakano, Masato; Makino, Hiroto; Mine, Hayato; Kimura, Tomoatsu

2016-03-01

Although direct vertebral rotation (DVR) is now used worldwide for the surgical treatment of adolescent idiopathic scoliosis (AIS), the benefit of DVR in reducing vertebral body rotation in these patients has not been determined. We investigated a possible additive effect of DVR on further reduction of vertebral body rotation in the axial plane following intraoperative rod rotation or differential rod contouring in patients undergoing surgical treatment for AIS. The study was a prospective computed tomography (CT) image analysis. We analyzed the results of the two intraoperative procedures in 30 consecutive patients undergoing surgery for AIS (Lenke type I or II: 15; Lenke type V: 15). The angle of reduction of vertebral body rotation taken by intraoperative CT scan was measured and analyzed. Pre- and postoperative responses to the Scoliosis Research Society 22 Questionnaire (SRS-22) were also analyzed. To analyze the reduction of vertebral body rotation with rod rotation or DVR, intraoperative cone-beam CT scans of the three apical vertebrae of the major curve of the scoliosis (90 vertebrae) were taken pre-rod rotation (baseline), post-rod rotation with differential rod contouring, and post-DVR in all patients. The angle of vertebral body rotation in these apical vertebrae was measured and analyzed for statistical significance. Additionally, differences between thoracic curve scoliosis (Lenke type I or II; 45 vertebrae) and thoracolumbar or lumbar curve scoliosis (Lenke type V; 45 vertebrae) were analyzed. Pre- and postoperative SRS-22 scores were evaluated in all patients. The mean (90 vertebrae) vertebral body rotation angles at baseline, post-rod rotation or differential rod contouring, and post-rod rotation or differential rod contouring or post-DVR were 17.3°, 11.1°, and 6.9°, respectively. The mean reduction in vertebral body rotation with the rod rotation technique was 6.8° for thoracic curves and 5.7° for thoracolumbar or lumbar curves (pself

Ultrafast rotation in an amphidynamic crystalline metal organic framework

Energy Technology Data Exchange (ETDEWEB)

Vogelsberg, Cortnie S.; Uribe-Romo, Fernando J.; Lipton, Andrew S.; Yang, Song; Houk, K. N.; Brown, Stuart; Garcia-Garibay, Miguel A.

2017-12-11

Amphidynamic crystals are an emergent class of condensed phase matter designed with a combination of lattice-forming elements linked to components that display engineered dynamics in the solid state. Here, we address the design of a crystalline array of molecular rotors with inertial diffusional rotation at the nanoscale, characterized by the absence of steric or electronic barriers. We solved this challenge with 1,4-bicyclo[2.2.2]octane dicarboxylic acid (BODCA)-MOF, a metal-organic framework (MOF) built with a high-symmetry bicyclo[2.2.2]octane dicarboxylate linker in a Zn₄O cubic lattice. Using spin-lattice relaxation ¹H solid-state NMR at 29.49 and 13.87 MHz in the temperature range of 2.3–80 K, we showed that internal rotation occurs in a potential with energy barriers of 0.185 kcal mol^-1. These results were confirmed with ²H solid-state NMR line-shape analysis and spin-lattice relaxation at 76.78 MHz obtained between 6 and 298 K, which, combined with molecular dynamics simulations, indicate that inertial diffusional rotation is characterized by a broad range of angular displacements with no residence time at any given site. The ambient temperature rotation of the bicyclo[2.2.2]octane (BCO) group in BODCA-MOF constitutes an example where engineered rotational dynamics in the solid state are as fast as they would be in a high-density gas or in a low-density liquid phase.

Solid state {sup 1}H spin-lattice relaxation and isolated-molecule and cluster electronic structure calculations in organic molecular solids: The relationship between structure and methyl group and t-butyl group rotation

Energy Technology Data Exchange (ETDEWEB)

Wang, Xianlong, E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Key Laboratory for NeuroInformation of Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, 4 North Jianshe Rd., 2nd Section, Chengdu 610054 (China); Mallory, Frank B. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Mallory, Clelia W. [Department of Chemistry, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States); Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323 (United States); Odhner, Hosanna R.; Beckmann, Peter A., E-mail: WangXianlong@uestc.edu.cn, E-mail: pbeckman@brynmawr.edu [Department of Physics, Bryn Mawr College, 101 North Merion Ave., Bryn Mawr, Pennsylvania 19010-2899 (United States)

2014-05-21

We report ab initio density functional theory electronic structure calculations of rotational barriers for t-butyl groups and their constituent methyl groups both in the isolated molecules and in central molecules in clusters built from the X-ray structure in four t-butyl aromatic compounds. The X-ray structures have been reported previously. We also report and interpret the temperature dependence of the solid state {sup 1}H nuclear magnetic resonance spin-lattice relaxation rate at 8.50, 22.5, and 53.0 MHz in one of the four compounds. Such experiments for the other three have been reported previously. We compare the computed barriers for methyl group and t-butyl group rotation in a central target molecule in the cluster with the activation energies determined from fitting the {sup 1}H NMR spin-lattice relaxation data. We formulate a dynamical model for the superposition of t-butyl group rotation and the rotation of the t-butyl group's constituent methyl groups. The four compounds are 2,7-di-t-butylpyrene, 1,4-di-t-butylbenzene, 2,6-di-t-butylnaphthalene, and 3-t-butylchrysene. We comment on the unusual ground state orientation of the t-butyl groups in the crystal of the pyrene and we comment on the unusually high rotational barrier of these t-butyl groups.

Motor Processes in Children's Mental Rotation

Science.gov (United States)

Frick, Andrea; Daum, Moritz M.; Walser, Simone; Mast, Fred W.

2009-01-01

Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a…

Advances in Molecular Rotational Spectroscopy for Applied Science

Science.gov (United States)

Harris, Brent; Fields, Shelby S.; Pulliam, Robin; Muckle, Matt; Neill, Justin L.

2017-06-01

Advances in chemical sensitivity and robust, solid-state designs for microwave/millimeter-wave instrumentation compel the expansion of molecular rotational spectroscopy as research tool into applied science. It is familiar to consider molecular rotational spectroscopy for air analysis. Those techniques for molecular rotational spectroscopy are included in our presentation of a more broad application space for materials analysis using Fourier Transform Molecular Rotational Resonance (FT-MRR) spectrometers. There are potentially transformative advantages for direct gas analysis of complex mixtures, determination of unknown evolved gases with parts per trillion detection limits in solid materials, and unambiguous chiral determination. The introduction of FT-MRR as an alternative detection principle for analytical chemistry has created a ripe research space for the development of new analytical methods and sampling equipment to fully enable FT-MRR. We present the current state of purpose-built FT-MRR instrumentation and the latest application measurements that make use of new sampling methods.

Self-motion perception and vestibulo-ocular reflex during whole body yaw rotation in standing subjects: the role of head position and neck proprioception.

Science.gov (United States)

Panichi, Roberto; Botti, Fabio Massimo; Ferraresi, Aldo; Faralli, Mario; Kyriakareli, Artemis; Schieppati, Marco; Pettorossi, Vito Enrico

2011-04-01

Self-motion perception and vestibulo-ocular reflex (VOR) were studied during whole body yaw rotation in the dark at different static head positions. Rotations consisted of four cycles of symmetric sinusoidal and asymmetric oscillations. Self-motion perception was evaluated by measuring the ability of subjects to manually track a static remembered target. VOR was recorded separately and the slow phase eye position (SPEP) was computed. Three different head static yaw deviations (active and passive) relative to the trunk (0°, 45° to right and 45° to left) were examined. Active head deviations had a significant effect during asymmetric oscillation: the movement perception was enhanced when the head was kept turned toward the side of body rotation and decreased in the opposite direction. Conversely, passive head deviations had no effect on movement perception. Further, vibration (100 Hz) of the neck muscles splenius capitis and sternocleidomastoideus remarkably influenced perceived rotation during asymmetric oscillation. On the other hand, SPEP of VOR was modulated by active head deviation, but was not influenced by neck muscle vibration. Through its effects on motion perception and reflex gain, head position improved gaze stability and enhanced self-motion perception in the direction of the head deviation. Copyright © 2010 Elsevier B.V. All rights reserved.

Post-middle Miocene Tuffs of Bodie Hills and Mono Basin, California: Paleomagnetic Reference Directions and Vertical Axis Rotation

Science.gov (United States)

Lindeman, J. R.; Pluhar, C. J.; Farner, M. J.

2013-12-01

The relative motions of the Pacific and North American plates about the Sierra Nevada-North American Euler pole is accommodated by dextral slip along the San Andreas Fault System (~75%) and the Walker Lane-Eastern California Shear Zone system of faults, east of the Sierra Nevada microplate (~25%). The Bodie Hills and Mono Basin regions lie within the Walker Lane and partially accommodate deformation by vertical axis rotation of up to 60o rotation since ~9.4 Ma. This region experienced recurrent eruptive events from mid to late Miocene, including John et al.'s (2012) ~12.05 Ma Tuff of Jack Springs (TJS) and Gilbert's (1968) 11.1 - 11.9 Ma 'latite ignimbrite' east of Mono Lake. Both tuffs can be identified by phenocrysts of sanidine and biotite in hand specimens, with TJS composed of a light-grey matrix and the latite ignimbrite composed of a grey-black matrix. Our paleomagnetic results show these units to both be normal polarity, with the latite ignimbrite exhibiting a shallow inclination. TJS's normal polarity is consistent with emplacement during subchron C5 An. 1n (12.014 - 12.116 Ma). The X-ray fluorescence analyses of fiamme from TJS in Bodie Hills and the latite ignimbrite located east of Mono Lake reveal them both to be rhyolites with the latite ignimbrite sharing elevated K composition seen in the slightly younger Stanislaus Group (9.0 - 10.2 Ma). We establish a paleomagnetic reference direction of D = 352.8o I = 42.7o α95 = 7.7o n = 5 sites (42 samples) for TJS in the Bodie Hills in a region hypothesized by Carlson (2012) to have experienced low rotation. Our reference for Gilbert's latite ignimbrite (at Cowtrack Mountain) is D = 352.9o I = 32.1o α95 = 4.7o. This reference locality is found on basement highland likely to have experienced less deformation then the nearby Mono Basin since ignimbrite emplacement. Paleomagnetic results from this latite ignimbrite suggests ~98.2o × 5.5o of clockwise vertical axis rotation of parts of eastern Mono Basin since

Recombination of radiation defects in solid methane: neutron sources and cryo-volcanism on celestial bodies

Science.gov (United States)

Kirichek, O.; Savchenko, E. V.; Lawson, C. R.; Khyzhniy, I. V.; Jenkins, D. M.; Uyutnov, S. A.; Bludov, M. A.; Haynes, D. J.

2018-03-01

Physicochemical properties of solid methane exposed to ionizing radiation have attracted significant interest in recent years. Here we present new trends in the study of radiation effects in solid methane. We particularly focus on relaxation phenomena in solid methane pre-irradiated by energetic neutrons and electron beam. We compare experimental results obtained in the temperature range from 10K to 100K with a model based on the assumption that radiolysis defect recombinations happen in two stages, at two different temperatures. In the case of slow heating up of the solid methane sample, irradiated at 10K, the first wave of recombination occurs around 20K with a further second wave taking place between 50 and 60K. We also discuss the role of the recombination mechanisms in “burp” phenomenon discovered by J. Carpenter in the late 1980s. An understanding of these mechanisms is vital for the designing and operation of solid methane moderators used in advanced neutron sources and could also be a possible explanation for the driving forces behind cryo-volcanism on celestial bodies.

The rotation of P/Halley

International Nuclear Information System (INIS)

Sagdeev, R.Z.; Szegoe, K.; Kondor, A.; Merenyi, E.; Smith, B.A.; Larson, S.; Toth, I.

1987-11-01

The nucleus of the comet Halley rotates as a slightly asymmetric top, the orientation of the rotation axis (the orientation of the angular momentum vector) is b=54 deg +-15 deg, l=219 deg +-15 deg in the ecliptic system. In the case of the rotation of an asymmetric top the rotation axis is not fixed rigidly to the body, which means that while the nucleus rotates around the axis with a period of 2.2+-0.05 d, its long axis 'nods' periodically with a period of 7.4+-0.05 d. The amplitude of the 'nodding' is about 15 deg +-3 deg in both directions relative to a plane perpendicular to the rotation axis. (author) 21 refs.; 6 figs.; 2 tabs

Solid waste containing method and solid waste container

International Nuclear Information System (INIS)

Sawai, Takeshi.

1997-01-01

Solid wastes are filled in a sealed vessel, and support spacers are inserted to the gap between the inner wall of a vessel main body and the solid wastes. The solid wastes comprise shorn pieces (crushed pieces) of spent fuel rod cladding tubes, radioactively contaminated metal pieces and miscellaneous solids pressed into a disk-like shape. The sealed vessel comprises, for example, a stainless steel. The solid wastes are filled while being stacked in a plurality of stages. A solidifying filler is filled into the gap between the inner wall and the solid wastes in the vessel main body by way of an upper opening, and the upper opening is closed by a closing lid to provide an entirely sealed state. Alumina particles having high heat conductivity and excellent heat durability are used for the solid filler. It is preferable to fill an inert gas such as a dried nitrogen gas in the sealed vessel. (I.N.)

On the Stability of Periodic Mercury-type Rotations

Science.gov (United States)

Churkina, Tatyana E.; Stepanov, Sergey Y.

2017-12-01

We consider the stability of planar periodic Mercury-type rotations of a rigid body around its center of mass in an elliptical orbit in a central Newtonian field of forces. Mercurytype rotations mean that the body makes 3 turns around its center of mass during 2 revolutions of the center of mass in its orbit (resonance 3:2). These rotations can be 1) symmetrical 2π- periodic, 2) symmetrical 4π-periodic and 3) asymmetrical 4π-periodic. The stability of rotations of type 1) was investigated by A.P.Markeev. In our paper we present a nonlinear stability analysis for some rotations of types 2) and 3) in 3rd- and 4th-order resonant cases, in the nonresonant case and at the boundaries of regions of linear stability.

Phase transitions in solid Kr-CH4 solutions and rotational excitations in phase II

International Nuclear Information System (INIS)

Bagatskii, M.I.; Mashchenko, D.A.; Dudkin, V.V.

2007-01-01

The heat capacity C p of solid Kr-n CH 4 solutions with the CH 4 concentrations n=0.82, 0.86, 0.90 as well as solutions with n=0.90, 0.95 doped with 0.002 O 2 impurity has been investigated under equilibrium vapor pressure over the internal 1-24 K. The (T,n)-phase diagram was refined and the region of two-phase states was determined for Kr-n CH 4 solid solutions. The contribution of the rotational subsystem, C r ot, to the heat capacity of the solutions has been separated. Analysis of C r ot(T) at T 1 and E 2 between the tunnel levels of the A-, T- and A-, E--nuclear-spin species of CH 4 molecules in the orientationally ordered subsystem, and to determine the effective energy gaps E 1 between lowest levels of the A- and T- species. The relations τ(n) and E 1 (n) stem from changes of the effective potential field caused as the replacement of CH 4 molecules by Kr atoms at sites of the ordered sublattices. The effective gaps E L between a group of tunnel levels of the ground-state liberation state and the nearest group of excited levels of the liberation state of the ordered CH 4 molecules in the solutions with n=0.90 (E L =52 K) and 0.95 (E L =55 K) has been estimated

Rotational structure in molecular infrared spectra

CERN Document Server

di Lauro, Carlo

2013-01-01

Recent advances in infrared molecular spectroscopy have resulted in sophisticated theoretical and laboratory methods that are difficult to grasp without a solid understanding of the basic principles and underlying theory of vibration-rotation absorption spectroscopy. Rotational Structure in Molecular Infrared Spectra fills the gap between these recent, complex topics and the most elementary methods in the field of rotational structure in the infrared spectra of gaseous molecules. There is an increasing need for people with the skills and knowledge to interpret vibration-rotation spectra in many scientific disciplines, including applications in atmospheric and planetary research. Consequently, the basic principles of vibration-rotation absorption spectroscopy are addressed for contemporary applications. In addition to covering operational quantum mechanical methods, spherical tensor algebra, and group theoretical methods applied to molecular symmetry, attention is also given to phase conventions and their effe...

Effect of foam stirrer design on the catalytic performance of rotating foam stirrer reactions

NARCIS (Netherlands)

Leon Matheus, M.A.; Geers, P.; Nijhuis, T.A.; Schaaf, van der J.; Schouten, J.C.

2012-01-01

The liquid–solid mass transfer rate in a rotating foam stirrer reactor and in a slurry reactor is studied using the hydrogenation of styrene as a model reaction. The rotating foam stirrer reactor is a novel type of multi-phase reactor where highly open-celled materials, solid foams, are used as a

Design of a deployment rotation mechanism for microsatellite

NARCIS (Netherlands)

Abdelal, G.F.; Bakr Elhady, A.; Kassab, M.

2009-01-01

Solar array rotation mechanism provides a hinged joint between the solar panel and satellite body, smooth rotation of the solar array into deployed position and its fixation in this position. After unlocking of solar panel (while in orbit), rotation bracket turns towards ready-to-work position under

Solid State Welding Development at Marshall Space Flight Center

Science.gov (United States)

Ding, Robert J.; Walker, Bryant

2012-01-01

What is TSW and USW? TSW is a solid state weld process consisting of an induction coil heating source, a stir rod, and non-rotating containment plates Independent heating, stirring and forging controls Decouples the heating, stirring and forging process elements of FSW. USW is a solid state weld process consisting of an induction coil heating source, a stir rod, and a non-rotating containment plate; Ultrasonic energy integrated into non-rotating containment plate and stir rod; Independent heating, stirring and forging controls; Decouples the heating, stirring and forging process elements of FSW.

Impaired mental rotation in benign paroxysmal positional vertigo and acute vestibular neuritis.

Directory of Open Access Journals (Sweden)

Matteo eCandidi

2013-11-01

Full Text Available Vestibular processing is fundamental to our sense of orientation in space which is a core aspect of the representation of the self. Vestibular information is processed in a large subcortical-cortical neural network. Tasks requiring mental rotations of human bodies in space are known to activate neural regions within this network suggesting that vestibular processing is involved in the control of mental rotation. We studied whether mental rotation is impaired in patients suffering from two different forms of unilateral vestibular disorders (Vestibular Neuritis – VN- and Benign Paroxysmal positional Vertigo – BPPV with respect to healthy matched controls (C. We used two mental rotation tasks in which participants were required to: i mentally rotate their own body in space (egocentric rotation thus using vestibular processing to a large extent and ii mentally rotate human figures (allocentric rotation thus using own body representations to a smaller degree. Reaction times and accuracy of responses showed that VN and BPPV patients were impaired in both tasks with respect to C. Significantly, the pattern of results was similar in the three groups suggesting that patients were actually performing the mental rotation without using a different strategy from the control individuals. These results show that dysfunctional vestibular inflow impairs mental rotation of both own body and human figures suggesting that unilateral acute disorders of the peripheral vestibular input massively affect the cerebral processes underlying mental rotations.

Rayleigh Waves in a Rotating Orthotropic Micropolar Elastic Solid Half-Space

Directory of Open Access Journals (Sweden)

Baljeet Singh

2013-01-01

Full Text Available A problem on Rayleigh wave in a rotating half-space of an orthotropic micropolar material is considered. The governing equations are solved for surface wave solutions in the half space of the material. These solutions satisfy the boundary conditions at free surface of the half-space to obtain the frequency equation of the Rayleigh wave. For numerical purpose, the frequency equation is approximated. The nondimensional speed of Rayleigh wave is computed and shown graphically versus nondimensional frequency and rotation-frequency ratio for both orthotropic micropolar elastic and isotropic micropolar elastic cases. The numerical results show the effects of rotation, orthotropy, and nondimensional frequency on the nondimensional speed of the Rayleigh wave.

Measurements of Drag Coefficients and Rotation Rates of Free-Falling Helixes

KAUST Repository

Al-Omari, Abdulrhaman A.

2016-05-01

The motion of bacteria in the environment is relevant to several fields. At very small scales and with simple helical shapes, we are able to describe experimentally and mathematically the motion of solid spirals falling freely within a liquid pool. Using these shapes we intend to mimic the motion of bacteria called Spirochetes. We seek to experimentally investigate the linear and the rotational motion of such shapes. A better understanding of the dynamics of this process will be practical not only on engineering and physics, but the bioscience and environmental as well. In the following pages, we explore the role of the shape on the motion of passive solid helixes in different liquids. We fabricate three solid helical shapes and drop them under gravity in water, glycerol and a mixture of 30% glycerol in water. That generated rotation due to helical angle in water. However, we observe the rotation disappear in glycerol. The movement of the solid helical shapes is imaged using a high-speed video camera. Then, the images are analyzed using the supplied software and a computer. Using these simultaneous measurements, we examine the terminal velocity of solid helical shapes. Using this information we computed the drag coefficient and the drag force. We obtain the helical angular velocity and the torque applied to the solid. The results of this study will allow us to more accurately predict the motion of solid helical shape. This analysis will also shed light onto biological questions of bacteria movement.

On the coherent rotation of diffuse matter in numerical simulations of clusters of galaxies

Science.gov (United States)

Baldi, Anna Silvia; De Petris, Marco; Sembolini, Federico; Yepes, Gustavo; Lamagna, Luca; Rasia, Elena

2017-03-01

We present a study on the coherent rotation of the intracluster medium and dark matter components of simulated galaxy clusters extracted from a volume-limited sample of the MUSIC project. The set is re-simulated with three different recipes for the gas physics: (I) non-radiative, (II) radiative without active galactic nuclei (AGN) feedback and (III) radiative with AGN feedback. Our analysis is based on the 146 most massive clusters identified as relaxed, 57 per cent of the total sample. We classify these objects as rotating and non-rotating according to the gas spin parameter, a quantity that can be related to cluster observations. We find that 4 per cent of the relaxed sample is rotating according to our criterion. By looking at the radial profiles of their specific angular momentum vector, we find that the solid body model is not a suitable description of rotational motions. The radial profiles of the velocity of the dark matter show a prevalence of the random velocity dispersion. Instead, the intracluster medium profiles are characterized by a comparable contribution from the tangential velocity and the dispersion. In general, the dark matter component dominates the dynamics of the clusters, as suggested by the correlation between its angular momentum and the gas one, and by the lack of relevant differences among the three sets of simulations.

Analytical Model of Doppler Spectra of Light Backscattered from Rotating Convex Bodies of Revolution in the Global Cartesian Coordinate System

International Nuclear Information System (INIS)

Yan-Jun, Gong; Zhen-Sen, Wu; Jia-Ji, Wu

2009-01-01

We present an analytical model of Doppler spectra in backscattering from arbitrary rough convex bodies of revolution rotating around their axes in the global Cartesian coordinate system. This analytical model is applied to analyse Doppler spectra in backscatter from two cones and two cylinders, as well as two ellipsoids of revolution. We numerically analyse the influences of attitude and geometry size of objects on Doppler spectra. The analytical model can give contribution of the surface roughness, attitude and geometry size of convex bodies of revolution to Doppler spectra and may contribute to laser Doppler velocimetry as well as ladar applications

Differential Rotation within the Earth's Outer Core

Science.gov (United States)

Hide, R.; Boggs, D. H.; Dickey, J. O.

1998-01-01

Non-steady differential rotation drive by bouyancy forces within the Earth's liquid outer core (OC) plays a key role not only in the generation of the main geomagnetic field by the magnetohydrodynamic (MHD) dynamo process but also in the excitation of irregular fluctuations in the angular speed of rotation of the overlying solid mantle, as evidenced by changes in the length of the day (LOD) on decadal and longer timescales (1-8).

Shell model for warm rotating nuclei

Energy Technology Data Exchange (ETDEWEB)

Matsuo, M.; Yoshida, K. [Kyoto Univ. (Japan); Dossing, T. [Univ. of Copenhagen (Denmark)] [and others

1996-12-31

Utilizing a shell model which combines the cranked Nilsson mean-field and the residual surface and volume delta two-body forces, the authors discuss the onset of rotational damping in normal- and super-deformed nuclei. Calculation for a typical normal deformed nucleus {sup 168}Yb indicates that the rotational damping sets in at around 0.8 MeV above the yrast line, and about 30 rotational bands of various length exists at a given rotational frequency, in overall agreement with experimental findings. It is predicted that the onset of rotational damping changes significantly in different superdeformed nuclei due to the variety of the shell gaps and single-particle orbits associated with the superdeformed mean-field.

Measurements of Drag Coefficients and Rotation Rates of Free-Falling Helixes

KAUST Repository

Al-Omari, Abdulrhaman A.

2016-01-01

in water, glycerol and a mixture of 30% glycerol in water. That generated rotation due to helical angle in water. However, we observe the rotation disappear in glycerol. The movement of the solid helical shapes is imaged using a high-speed video camera

Hall current and Joule heating effects on peristaltic flow of viscous fluid in a rotating channel with convective boundary conditions

Directory of Open Access Journals (Sweden)

Tasawar Hayat

Full Text Available The present article has been arranged to study the Hall current and Joule heating effects on peristaltic flow of viscous fluid in a channel with flexible walls. Both fluid and channel are in a state of solid body rotation. Convective conditions for heat transfer in the formulation are adopted. Viscous dissipation in energy expression is taken into account. Resulting differential systems after invoking small Reynolds number and long wavelength considerations are numerically solved. Runge-Kutta scheme of order four is implemented for the results of axial and secondary velocities, temperature and heat transfer coefficient. Comparison with previous limiting studies is shown. Outcome of new parameters of interest is analyzed. Keywords: Rotating frame, Hall current, Joule heating, Convective conditions, Wall properties

Raynal–Revai coefficients for a general kinematic rotation

International Nuclear Information System (INIS)

Ershov, S. N.

2016-01-01

In a three-body system, transitions between different sets of normalized Jacobi coordinates are described as general kinematic transformations that include an orthogonal or a pseudoorthogonal rotation. For such rotations, the Raynal–Revai coefficients execute a unitary transformation between three-body hyperspherical functions. Recurrence relations that make it possible to calculate the Raynal–Revai coefficients for arbitrary angular momenta are derived on the basis of linearized representations of products of hyperspherical functions.

Hydrogen Pellet-Rotating Plasma Interaction

DEFF Research Database (Denmark)

Jørgensen, L. W.; Sillesen, Alfred Hegaard; Øster, Flemming

1977-01-01

Spectroscopic measurements on the interaction between solid hydrogen pellets and rotating plasmas are reported. It was found that the light emitted is specific to the pellet material, and that the velocity of the ablated H-atoms is of the order of l0^4 m/s. The investigation was carried out...

A rotating helical sealing joint capable of partially melting

International Nuclear Information System (INIS)

Martin, Jean; Ollier, J.-L.; Petit, Paul.

1973-01-01

A coagulated rotating helical joint providing gas and liquid tightness along a rotating shaft, comprising: a metal sleeve connected to the wall through which passes the rotating sleeve, an intermediate sleeve made of a fusible material, inert with respect to the fluid to be sealingly retained, and finally the rotating shaft provided with an engraved helical thread in register with the intermediate sleeve. Means are provided for regulating the intermediate sleeve temperature so that a thin melted film is formed on said intermediate sleeve when in contact with the rotating threaded shaft. This can be applied in the nuclear industry, including cases when the intermediate sleeve is constituted by the fluid itself, then in the solid state [fr

Rates and timing of vertical-axis block rotations across the Sierra Nevada-Walker Lane transition in the Bodie Hills

Science.gov (United States)

Rood, D. H.; Herman, S.; Burbank, D.; Bogue, S.

2008-12-01

We use paleomagnetic data from Tertiary volcanic rocks to address the rates and timing of vertical-axis block rotation across the Sierra Nevada-Walker Lane transition in the Bodie Hills, California/Nevada. In zones of continental deformation, block rotations are an important mechanism for permanent stain accommodation, and thus may be crucial to testing geodetic block models and resolving geologic-geodetic slip discrepancies. In our study, data included in the paleomagetic site means are high quality AF demagnetization results (least squared fits that generally include 5-7 points with MAD values less than 1). Thermal demagnetization results match the AF directions, and both thermal demag and rockmag results indicate strong ChRM, mostly carried by single domain magnetite. The site means used to calculate the VGPs all have a95 values less than 10 (mostly 2-5) and include 6-11 sites each. Each site (and thus site mean) has a reasonably well-known structural correction. The VGP scatter values range from 12 to 16 degrees, indicating that they include appropriate secular variation. The mean declinations and 95 percent confidence limits for each VGP timeslice are statistically distinct from one another (71 ± 9, 39 ± 13, and 11 ± 11 degrees). The slope of a linear regression fit to the age versus declination data gives a rate of vertical axis block rotation of approximately 3-4 degrees/Myr. Fitting two separate lines to the age vs. declination data would indicate an increase in the rates of rotation since ~10 Ma. Two possible interpretations of the data are: (1) the rotations began during or before the Middle Miocene, or (2) rates of rotation were high initially (e.g. ~10 Ma) and decelerated until the Pliocene. These data have implications for the (1) timing and spatial extent of distributed strain accumulation related to the initiation of the San Andreas Fault-Eastern California Shear Zone-Walker Lane transform plate boundary, (2) transfer of transform plate boundary

Body Context and Posture Affect Mental Imagery of Hands

Science.gov (United States)

Ionta, Silvio; Perruchoud, David; Draganski, Bogdan; Blanke, Olaf

2012-01-01

Different visual stimuli have been shown to recruit different mental imagery strategies. However the role of specific visual stimuli properties related to body context and posture in mental imagery is still under debate. Aiming to dissociate the behavioural correlates of mental processing of visual stimuli characterized by different body context, in the present study we investigated whether the mental rotation of stimuli showing either hands as attached to a body (hands-on-body) or not (hands-only), would be based on different mechanisms. We further examined the effects of postural changes on the mental rotation of both stimuli. Thirty healthy volunteers verbally judged the laterality of rotated hands-only and hands-on-body stimuli presented from the dorsum- or the palm-view, while positioning their hands on their knees (front postural condition) or behind their back (back postural condition). Mental rotation of hands-only, but not of hands-on-body, was modulated by the stimulus view and orientation. Additionally, only the hands-only stimuli were mentally rotated at different speeds according to the postural conditions. This indicates that different stimulus-related mechanisms are recruited in mental rotation by changing the bodily context in which a particular body part is presented. The present data suggest that, with respect to hands-only, mental rotation of hands-on-body is less dependent on biomechanical constraints and proprioceptive input. We interpret our results as evidence for preferential processing of visual- rather than kinesthetic-based mechanisms during mental transformation of hands-on-body and hands-only, respectively. PMID:22479618

A Microscopic Quantal Model for Nuclear Collective Rotation

International Nuclear Information System (INIS)

Gulshani, P.

2007-01-01

A microscopic, quantal model to describe nuclear collective rotation in two dimensions is derived from the many-nucleon Schrodinger equation. The Schrodinger equation is transformed to a body-fixed frame to decompose the Hamiltonian into a sum of intrinsic and rotational components plus a Coriolis-centrifugal coupling term. This Hamiltonian (H) is expressed in terms of space-fixed-frame particle coordinates and momenta by using commutator of H with a rotation angle. A unified-rotational-model type wavefunction is used to obtain an intrinsic Schrodinger equation in terms of angular momentum quantum number and two-body operators. A Hartree-Fock mean-field representation of this equation is then obtained and, by means of a unitary transformation, is reduced to a form resembling that of the conventional semi-classical cranking model when exchange terms and intrinsic spurious collective excitation are ignored

Baseline toxicity of a chlorobenzene mixture and total body residues measured and estimated with solid-phase microextraction

NARCIS (Netherlands)

Leslie, H.A.; Hermens, J.L.; Kraak, M.H.S.

2004-01-01

Body residues of compounds with a narcotic mode of action that exceed critical levels result in baseline toxicity in organisms. Previous studies have shown that internal concentrations in organisms also can be estimated by way of passive sampling. In this experiment, solid-phase microextraction

Degenerative full thickness rotator cuff tears : Towards optimal management

NARCIS (Netherlands)

Lambers Heerspink, Frederik

2016-01-01

The shoulder is one of the most complex joints in the body. Besides a wide range of motion it also has to be stable. The rotator cuff is a major stabiliser of the glenohumoral joint. With increasing age rotator cuff tears are common. Successful treatment is described following surgical (rotator cuff

Three-dimensional rotational plasma flows near solid surfaces in an axial magnetic field

Energy Technology Data Exchange (ETDEWEB)

Gorshunov, N. M., E-mail: gorshunov-nm@nrcki.ru; Potanin, E. P., E-mail: potanin45@yandex.ru [National Research Center Kurchatov Institute (Russian Federation)

2016-11-15

A rotational flow of a conducting viscous medium near an extended dielectric disk in a uniform axial magnetic field is analyzed in the magnetohydrodynamic (MHD) approach. An analytical solution to the system of nonlinear differential MHD equations of motion in the boundary layer for the general case of different rotation velocities of the disk and medium is obtained using a modified Slezkin–Targ method. A particular case of a medium rotating near a stationary disk imitating the end surface of a laboratory device is considered. The characteristics of a hydrodynamic flow near the disk surface are calculated within the model of a finite-thickness boundary layer. The influence of the magnetic field on the intensity of the secondary flow is studied. Calculations are performed for a weakly ionized dense plasma flow without allowance for the Hall effect and plasma compressibility. An MHD flow in a rotating cylinder bounded from above by a retarding cap is considered. The results obtained can be used to estimate the influence of the end surfaces on the main azimuthal flow, as well as the intensities of circulating flows in various devices with rotating plasmas, in particular, in plasma centrifuges and laboratory devices designed to study instabilities of rotating plasmas.

Mental rotation and the motor system: embodiment head over heels.

Science.gov (United States)

Krüger, Markus; Amorim, Michel-Ange; Ebersbach, Mirjam

2014-01-01

We examined whether body parts attached to abstract stimuli automatically force embodiment in a mental rotation task. In Experiment 1, standard cube combinations reflecting a human pose were added with (1) body parts on anatomically possible locations, (2) body parts on anatomically impossible locations, (3) colored end cubes, and (4) simple end cubes. Participants (N=30) had to decide whether two simultaneously presented stimuli, rotated in the picture plane, were identical or not. They were fastest and made less errors in the possible-body condition, but were slowest and least accurate in the impossible-body condition. A second experiment (N=32) replicated the results and ruled out that the poor performance in the impossible-body condition was due to the specific stimulus material. The findings of both experiments suggest that body parts automatically trigger embodiment, even when it is counterproductive and dramatically impairs performance, as in the impossible-body condition. It can furthermore be concluded that body parts cannot be used flexibly for spatial orientation in mental rotation tasks, compared to colored end cubes. Thus, embodiment appears to be a strong and inflexible mechanism that may, under certain conditions, even impede performance. Copyright © 2013 Elsevier B.V. All rights reserved.

Counter-Rotatable Fan Gas Turbine Engine with Axial Flow Positive Displacement Worm Gas Generator

Science.gov (United States)

Giffin, Rollin George (Inventor); Murrow, Kurt David (Inventor); Fakunle, Oladapo (Inventor)

2014-01-01

A counter-rotatable fan turbine engine includes a counter-rotatable fan section, a worm gas generator, and a low pressure turbine to power the counter-rotatable fan section. The low pressure turbine maybe counter-rotatable or have a single direction of rotation in which case it powers the counter-rotatable fan section through a gearbox. The gas generator has inner and outer bodies having offset inner and outer axes extending through first, second, and third sections of a core assembly. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes and extending radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. A combustor section extends through at least a portion of the second section.

Rigid-body rotation of an electron cloud in divergent magnetic fields

International Nuclear Information System (INIS)

Fruchtman, A.; Gueroult, R.; Fisch, N. J.

2013-01-01

For a given voltage across a divergent poloidal magnetic field, two electric potential distributions, each supported by a rigid-rotor electron cloud rotating with a different frequency, are found analytically. The two rotation frequencies correspond to the slow and fast rotation frequencies known in uniform plasma. Due to the centrifugal force, the equipotential surfaces, that correspond to the two electric potential distributions, diverge more than the magnetic surfaces do, the equipotential surfaces in the fast mode diverge largely in particular. The departure of the equipotential surfaces from the magnetic field surfaces may have a significant focusing effect on the ions accelerated by the electric field. The focusing effect could be important for laboratory plasma accelerators as well as for collimation of astrophysical jets

Efficiency of wave-driven rigid body rotation toroidal confinement

Science.gov (United States)

Rax, J. M.; Gueroult, R.; Fisch, N. J.

2017-03-01

The compensation of vertical drifts in toroidal magnetic fields through a wave-driven poloidal rotation is compared with compensation through the wave driven toroidal current generation to support the classical magnetic rotational transform. The advantages and drawbacks associated with the sustainment of a radial electric field are compared with those associated with the sustainment of a poloidal magnetic field both in terms of energy content and power dissipation. The energy content of a radial electric field is found to be smaller than the energy content of a poloidal magnetic field for a similar set of orbits. The wave driven radial electric field generation efficiency is similarly shown, at least in the limit of large aspect ratio, to be larger than the efficiency of wave-driven toroidal current generation.

Flow visualization around a rotating body in a wind tunnel

Science.gov (United States)

Hiraki, K.; Zaitsu, D.; Yanaga, Y.; Kleine, H.

2017-02-01

The rotational behavior of capsule-shaped models is investigated in the transonic wind tunnel of JAXA. A special support is developed to allow the model to rotate around the pitch, yaw and roll axes. This 3-DOF free rotational mounting apparatus achieves the least frictional torque from the support and the instruments. Two types of capsule models are prepared, one is drag type (SPH model) and the other is lift type (HTV-R model). The developed mounting apparatus is used in the wind tunnel tests with these capsule models. In a flow of Mach 0.9, the SPH model exhibits oscillations in pitch and yaw, and it rolls half a turn during the test. Similarly, the HTV-R model exhibits pitch and yaw oscillations in a flow of Mach 0.5. Moreover, it rolls multiple times during the test. In order to investigate the flow field around the capsule, the combined technique of color schlieren and surface tufts is applied. This visualization clearly shows the flow reattachment on the back surface of a capsule, which is suspected to induce the rapid rolling motion.

The role of rotational hand movements and general motor ability in children’s mental rotation performance

Directory of Open Access Journals (Sweden)

Petra eJansen

2015-07-01

Full Text Available Mental rotation of visual images of body parts and abstract shapes can be influenced by simultaneous motor activity. Children in particular seem to have a strong coupling between motor and cognitive processes. We investigated the influence of a rotational hand movement performed by rotating a knob on mental rotation performance in primary school-age children (N= 83; Age range: 7.0-8.3 and 9.0-10.11 years. In addition, we assessed the role of motor ability in this relationship. Boys in the 7-8-year-old group were faster when mentally and manually rotating in the same direction than in the opposite direction. For girls and older children this effect was not found. A positive relationship was found between motor ability and accuracy on the mental rotation task: stronger motor ability related to improved mental rotation performance. In both age groups, children with more advanced motor abilities were more likely to adopt motor processes to solve mental rotation tasks if the mental rotation task was primed by a motor task. Our evidence supports the idea that an overlap between motor and visual cognitive processes in children is influenced by motor ability.

Rotation of quantum impurities in the presence of a many-body environment

Science.gov (United States)

Lemeshko, Mikhail; Schmidt, Richard

2015-05-01

Pioneered by the seminal works of Wigner and Racah, the quantum theory of angular momentum evolved into a powerful machinery, commonly used to classify the states of isolated quantum systems and perturbations to their structure due to electromagnetic or crystalline fields. In ``realistic'' experiments, however, quantum systems are almost inevitably coupled to a many-particle environment and a field of elementary excitations associated with it, which is capable of fundamentally altering the physics of the system. We present the first systematic treatment of quantum rotation coupled to a many-particle environment. By using a series of canonical transformations on a generic microscopic Hamiltonian, we single out the conserved quantities of the problem. Using a variational ansatz accounting for an infinite number of many-body excitations, we characterize the spectrum of angular momentum eigenstates and identify the regions of instability, accompanied by emission of angular Cerenkov radiation. The developed technique can be applied to a wide range of systems described by the angular momentum algebra, from Rydberg atoms immersed into BEC's, to cold molecules solvated in helium droplets, to ultracold molecular ions.

Effects of humeral head compression taping on the isokinetic strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis.

Science.gov (United States)

Kim, Moon-Hwan; Oh, Jae-Seop

2015-01-01

[Purpose] The purpose of this study was to examine the effects of humeral head compression taping (HHCT) on the strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis. [Subjects and Methods] Twenty patients with rotator cuff tendinitis were recruited. The shoulder external rotator strength was measured using a Biodex isokinetic dynamometer system. A paired t-test was performed to evaluate within-group differences in the strength of the shoulder external rotator muscle. [Results] Significantly higher shoulder external rotator peak torque and peak torque per body weight were found in the HHCT condition than in the no-taping condition. [Conclusion] HHCT may effectively increase the shoulder external rotator muscle strength in patients with rotator cuff tendinitis.

Free and binary rotation of polyatomic molecules

International Nuclear Information System (INIS)

Konyukhov, V K

2003-01-01

A modification of the quantum-mechanical theory of rotation of polyatomic molecules (binary rotation) is proposed, which is based on the algebra and representations of the SO(4) group and allows the introduction of the concept of parity, as in atomic spectroscopy. It is shown that, if an asymmetric top molecule performing binary rotation finds itself in a spatially inhomogeneous electric field, its rotational levels acquire the additional energy due to the quadrupole moment. The existence of the rotational states of polyatomic molecules that cannot transfer to the free rotation state is predicted. In particular, the spin isomers of a water molecule, which corresponds to such states, can have different absolute values of the adsorption energy due to the quadrupole interaction of the molecule with a surface. The difference in the adsorption energies allows one to explain qualitatively the behaviour of the ortho- and para-molecules of water upon their adsorption on the surface of solids in accordance with experimental data. (laser applications and other topics in quantum electronics)

Variations of the Earth's rotation rate and cyclic processes in geodynamics

Directory of Open Access Journals (Sweden)

B.W. Levin

2017-05-01

Full Text Available The authors analyzed the relationship between variations of the Earth's rotation rate and the geodynamic processes within the Earth's body, including seismic activity. The rotation rate of a planet determines its uniaxial compression along the axis of rotation and the areas of various surface elements of the body. The Earth's ellipticity variations, caused naturally by the rotation rate variations, are manifested in vertical components of precise GPS measurements. Comparative analysis of these variations is considered in view of modern theoretical ideas concerning the Earth's figure. The results justify further research that is of interest for improvement of space systems and technologies.

Biomechanical comparison of traditional anchors to all-suture anchors in a double-row rotator cuff repair cadaver model.

Science.gov (United States)

Goschka, Andrew M; Hafer, Jason S; Reynolds, Kirk A; Aberle, Nicholas S; Baldini, Todd H; Hawkins, Monica J; McCarty, Eric C

2015-10-01

To further reduce the invasiveness of arthroscopic rotator cuff repair surgery the all-suture anchor has been developed. The all-suture anchor requires less bone removal and reduces the potential of loose body complications. The all-suture anchor must also have adequate biomechanical strength for the repair to heal. The hypothesis is there is no significant difference in the biomechanical performance of supraspinatus repairs using an all-suture anchor when compared to traditional solid-body suture anchors. Using nine shoulders per group, the supraspinatus tendon was dissected from the greater tuberosity. The four different double row repairs tested were (medial row/lateral row): A: ICONIX2/ICONIX2; B: ICONIX2/Stryker ReelX 3.9mm; C: ICONIX2/Stryker ReelX 4.5mm; D: Arthrex BioComposite CorkScrew FT 4.5mm/Arthrex BioComposite SwiveLock 4.75mm. The ICONIX2 was the only all-suture anchor tested. Tendons underwent cyclic loading from 10 to 100N for 500 cycles, followed by load-to-failure. Data was collected at cycles 5, 100, 200, 300, 400, and 500. One-way ANOVA analysis was used to assess significance (P≤0.05). The anchor combinations tested did not differ significantly in anterior (P>0.4) or posterior (P>0.3) gap formation, construct stiffness (P>0.7), ultimate load (P=0.06), or load to 5mm gap formation (P=0.84). The all-suture anchor demonstrated comparable biomechanical performance in multiple double-row anchor combinations to a combination of traditional solid-body anchors. Thus it may be an attractive option to further reduce the invasiveness of rotator cuff repairs. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dizzy people perform no worse at a motor imagery task requiring whole body mental rotation; a case-control comparison

Directory of Open Access Journals (Sweden)

Sarah B Wallwork

2013-06-01

Full Text Available We wanted to find out whether people who suffer from dizziness take longer than people who do not, to perform a motor imagery task that involves implicit whole body rotation. Our prediction was that people in the ‘dizzy’ group would take longer at a left/right neck rotation judgment task but not a left/right hand judgment task, because actually performing the former, but not the latter, would exacerbate their dizziness. Secondly, we predicted that when dizzy participants responded to neck rotation images, responses would be greatest when images were in the upside-down orientation; an orientation with greatest dizzy-provoking potential. To test this idea, we used a case-control comparison design. One hundred and eighteen participants who suffered from dizziness and 118 age, gender, arm pain and neck pain matched controls took part in the study. Participants undertook two motor imagery tasks; a left/right neck rotation judgment task and a left/right hand judgment task. The tasks were completed using the Recognise program; an on-line reaction time task program. Images of neck rotation were shown in four different orientations; 0°, 90°, 180° and 270°. Participants were asked to respond to each ‘neck’ image identifying it as either ‘right neck rotation’ or a ‘left neck rotation’, or for hands, a right or a left hand. Results showed that participants in the ‘dizzy’ group were slower than controls at both tasks (p= 0.015, but this was not related to task (p= 0.498. Similarly, ‘dizzy’ participants were not proportionally worse at images of different orientations (p= 0.878. Our findings suggest impaired performance in dizzy people, an impairment that may be confined to motor imagery or may extend more generally.

Rotation induced flow suppression around two tandem circular cylinders at low Reynolds number

Energy Technology Data Exchange (ETDEWEB)

Chatterjee, Dipankar [Advanced Design and Analysis Group, CSIR—Central Mechanical Engineering Research Institute, Durgapur-713209 (India); Gupta, Krishan [Department of Mechanical Engineering, Sardar Vallabhai National Institute of Technology Surat, Surat-395007 (India); Kumar, Virendra [Department of Mechanical Engineering, Indian Institute of Technology Patna, Patna-800013 (India); Varghese, Sachin Abraham, E-mail: d_chatterjee@cmeri.res.in [Department of Mechanical Engineering, National Institute of Technology Durgapur, Durgapur-713209 (India)

2017-08-15

The rotation to a bluff object is known to have a stabilizing effect on the fluid dynamic transport around the body. An unsteady periodic flow can be degenerated into a steady flow pattern depending on the rate of rotation imparted to the body. On the other hand, multiple bodies placed in tandem arrangement with respect to an incoming flow can cause destabilization to the flow as a result of the complicated wake interaction between the bodies. Accordingly, the spacing between the bodies and the rate of rotation have significant impact on the overall fluid dynamic transport around them. The present work aims to understand how these two competing factors are actually influencing the fluidic transport across a pair of identical rotating circular cylinders kept in tandem arrangement in an unconfined medium. The cylinders are subjected to a uniform free stream flow and the gaps between the cylinders are varied as 0.2, 0.7, 1.5 and 3.0. Both the cylinders are made to rotate in the clockwise sense. The Reynolds number based on the free stream flow is taken as 100. A two-dimensional finite volume based transient computation is performed for a range of dimensionless rotational speeds of the cylinders (0 ≤ Ω ≤ 2.75). The results show that the shedding phenomena can be observed up to a critical rate of rotation (Ω{sub cr}) depending on the gap spacing. Beyond Ω{sub cr}, the flow becomes stabilized and finally completely steady as Ω increases further. Increasing the gap initially causes a slight decrease in the critical rotational speed, however, it increases at a rapid rate for larger gap spacing. (paper)

Laser spectroscopic studies of the pure rotational U0(0) and W0(0) transitions of solid parahydrogen

International Nuclear Information System (INIS)

Chan, M.; Lee, S.S.; Okumura, M.; Oka, T.

1991-01-01

High resolution spectrum of multipole-induced transitions of solid parahydrogen was recorded using diode and difference frequency laser spectroscopy. The J=4 left-arrow 0 pure rotational U 0 (0) transition observed in the diode spectrum agrees well in frequency with the value reported by Balasubramanian et al. [Phys. Rev. Lett. 47, 1277 (1981)] but we observed a spectral width smaller by about a factor of 4. The J=6 left-arrow 0 W 0 (0) transition was observed to be exceedingly sharp, with a width of ∼70 MHz, using a difference frequency spectrometer with tone-burst modulation. This transition is composed of three components with varying relative intensity depending upon the direction of polarization of laser radiation. These components were interpreted as the splitting of the M levels in the J=6 state due to crystal field interactions. In addition, a new broad feature was found at 2452.4 cm -1 in the low resolution Fourier-transform infrared (FTIR) spectrum of solid hydrogen and was assigned to be the phonon branch W R (0) transition of the W 0 (0) line. The selection rules, crystal field splitting of J=4 and J=6 rotons, and the measured linewidth based on these observations are discussed

Statistical mechanics and correlation properties of a rotating two-dimensional flow of like-sign vortices

International Nuclear Information System (INIS)

Viecelli, J.A.

1993-01-01

The Hamiltonian flow of a set of point vortices of like sign and strength has a low-temperature phase consisting of a rotating triangular lattice of vortices, and a normal temperature turbulent phase consisting of random clusters of vorticity that orbit about a common center along random tracks. The mean-field flow in the normal temperature phase has similarities with turbulent quasi-two-dimensional rotating laboratory and geophysical flows, whereas the low-temperature phase displays effects associated with quantum fluids. In the normal temperature phase the vortices follow power-law clustering distributions, while in the time domain random interval modulation of the vortex orbit radii fluctuations produces singular fractional exponent power-law low-frequency spectra corresponding to time autocorrelation functions with fractional exponent power-law tails. Enhanced diffusion is present in the turbulent state, whereas in the solid-body rotation state vortices thermally diffuse across the lattice. Over the entire temperature range the interaction energy of a single vortex in the field of the rest of the vortices follows positive temperature Fermi--Dirac statistics, with the zero temperature limit corresponding to the rotating crystal phase, and the infinite temperature limit corresponding to a Maxwellian distribution. Analyses of weather records dependent on the large-scale quasi-two-dimensional atmospheric circulation suggest the presence of singular fractional exponent power-law spectra and fractional exponent power-law autocorrelation tails, consistent with the theory

Design of the all solid high-voltage power supply for a gyrotron body

Energy Technology Data Exchange (ETDEWEB)

Rao, Yihua [School of Mathematics and Physics, University of South China, Hengyang, 421001 (China); Chen, Wenguang, E-mail: 430000485393@usc.edu.cn [School of Electrical Engineering, University of South China, Hengyang, 421001 (China); Hu, Bo [School of Electrical Engineering, University of South China, Hengyang, 421001 (China); Rao, Jun; Huang, Mei; Kang, Zihua; Feng, Kun [Southwestern Institute of Physics, Chengdu, 610041 (China); Huang, Jiaqi [School of Electrical Engineering, University of South China, Hengyang, 421001 (China)

2017-04-15

Highlights: • Completed design of all solid-state high-voltage power supply for gyrotron body on HL-2M ECRH. • Consist of 58 PSM modules and one BUCK module, controlled by DSP system. • Fabricated full voltage 35 kV, 200 mA BPS and tested in dummy load. • The BPS can operate in three modes: single pulse mode, multi-pulse modulation mode and the six-level preset mode. - Abstract: Gyrotron plays an important role in the research of electron cyclotron resonance heating (ECRH) on Tokomak. The high-frequency switched power supply technology and pulse step modulation (PSM) technology are used in the development of the all solid high-voltage body power supply (BPS) for 1 MW/105 GHz Gyrotron on ECRH system. Firstly, the basic structure of the BPS and its control system are introduced. Secondly, the software control algorithm of voltage stabilization and modulate method are developed. Finally, the design is verified by the experiments. The experimental results of the single pulse mode, the multi-pulse modulation mode and the six-level preset mode, are shown. The output voltage of the power supply can reach 35 kV and the current at about 200 mA, which are adjustable in the full range. The maximum modulation frequency can reach 1 kHz and the front edge of the pulse can be adjust from 0 to 3 ms and the accuracy of the output voltage is less than 100 V. The results show that the control method is feasible and can be applied to other high power microwave sources.

An Lq-approach with generalized anisotropic weight of the weak solution of the Oseen flow around a rotating body in the whole space

Czech Academy of Sciences Publication Activity Database

Kračmar, S.; Krbec, Miroslav; Nečasová, Šárka; Penel, P.; Schumacher, K.

2009-01-01

Roč. 71, č. 12 (2009), e2940-e2957 ISSN 0362-546X R&D Projects: GA AV ČR IAA100190804 Institutional research plan: CEZ:AV0Z10190503 Keywords : littlewood-Paley theory * maximal operators * rotating body * Muckenhoupt weights * one-sided weights Subject RIV: BA - General Mathematics Impact factor: 1.487, year: 2009

Direct numerical simulation of moderate-Reynolds-number flow past arrays of rotating spheres

Science.gov (United States)

Zhou, Qiang; Fan, Liang-Shih

2015-07-01

Direct numerical simulations with an immersed boundary-lattice Boltzmann method are used to investigate the effects of particle rotation on flows past random arrays of mono-disperse spheres at moderate particle Reynolds numbers. This study is an extension of a previous study of the authors [Q. Zhou and L.-S. Fan, "Direct numerical simulation of low-Reynolds-number flow past arrays of rotating spheres," J. Fluid Mech. 765, 396-423 (2015)] that explored the effects of particle rotation at low particle Reynolds numbers. The results of this study indicate that as the particle Reynolds number increases, the normalized Magnus lift force decreases rapidly when the particle Reynolds number is in the range lower than 50. For the particle Reynolds number greater than 50, the normalized Magnus lift force approaches a constant value that is invariant with solid volume fractions. The proportional dependence of the Magnus lift force on the rotational Reynolds number (based on the angular velocity and the diameter of the spheres) observed at low particle Reynolds numbers does not change in the present study, making the Magnus lift force another possible factor that can significantly affect the overall dynamics of fluid-particle flows other than the drag force. Moreover, it is found that both the normalized drag force and the normalized torque increase with the increase of the particle Reynolds number and the solid volume fraction. Finally, correlations for the drag force, the Magnus lift force, and the torque in random arrays of rotating spheres at arbitrary solids volume fractions, rotational Reynolds numbers, and particle Reynolds numbers are formulated.

Development of a morphology-based modeling technique for tracking solid-body displacements: examining the reliability of a potential MRI-only approach for joint kinematics assessment

International Nuclear Information System (INIS)

Mahato, Niladri K.; Montuelle, Stephane; Cotton, John; Williams, Susan; Thomas, James; Clark, Brian

2016-01-01

Single or biplanar video radiography and Roentgen stereophotogrammetry (RSA) techniques used for the assessment of in-vivo joint kinematics involves application of ionizing radiation, which is a limitation for clinical research involving human subjects. To overcome this limitation, our long-term goal is to develop a magnetic resonance imaging (MRI)-only, three dimensional (3-D) modeling technique that permits dynamic imaging of joint motion in humans. Here, we present our initial findings, as well as reliability data, for an MRI-only protocol and modeling technique. We developed a morphology-based motion-analysis technique that uses MRI of custom-built solid-body objects to animate and quantify experimental displacements between them. The technique involved four major steps. First, the imaging volume was calibrated using a custom-built grid. Second, 3-D models were segmented from axial scans of two custom-built solid-body cubes. Third, these cubes were positioned at pre-determined relative displacements (translation and rotation) in the magnetic resonance coil and scanned with a T 1 and a fast contrast-enhanced pulse sequences. The digital imaging and communications in medicine (DICOM) images were then processed for animation. The fourth step involved importing these processed images into an animation software, where they were displayed as background scenes. In the same step, 3-D models of the cubes were imported into the animation software, where the user manipulated the models to match their outlines in the scene (rotoscoping) and registered the models into an anatomical joint system. Measurements of displacements obtained from two different rotoscoping sessions were tested for reliability using coefficient of variations (CV), intraclass correlation coefficients (ICC), Bland-Altman plots, and Limits of Agreement analyses. Between-session reliability was high for both the T 1 and the contrast-enhanced sequences. Specifically, the average CVs for translation were 4

Development of a morphology-based modeling technique for tracking solid-body displacements: examining the reliability of a potential MRI-only approach for joint kinematics assessment.

Science.gov (United States)

Mahato, Niladri K; Montuelle, Stephane; Cotton, John; Williams, Susan; Thomas, James; Clark, Brian

2016-05-18

Single or biplanar video radiography and Roentgen stereophotogrammetry (RSA) techniques used for the assessment of in-vivo joint kinematics involves application of ionizing radiation, which is a limitation for clinical research involving human subjects. To overcome this limitation, our long-term goal is to develop a magnetic resonance imaging (MRI)-only, three dimensional (3-D) modeling technique that permits dynamic imaging of joint motion in humans. Here, we present our initial findings, as well as reliability data, for an MRI-only protocol and modeling technique. We developed a morphology-based motion-analysis technique that uses MRI of custom-built solid-body objects to animate and quantify experimental displacements between them. The technique involved four major steps. First, the imaging volume was calibrated using a custom-built grid. Second, 3-D models were segmented from axial scans of two custom-built solid-body cubes. Third, these cubes were positioned at pre-determined relative displacements (translation and rotation) in the magnetic resonance coil and scanned with a T1 and a fast contrast-enhanced pulse sequences. The digital imaging and communications in medicine (DICOM) images were then processed for animation. The fourth step involved importing these processed images into an animation software, where they were displayed as background scenes. In the same step, 3-D models of the cubes were imported into the animation software, where the user manipulated the models to match their outlines in the scene (rotoscoping) and registered the models into an anatomical joint system. Measurements of displacements obtained from two different rotoscoping sessions were tested for reliability using coefficient of variations (CV), intraclass correlation coefficients (ICC), Bland-Altman plots, and Limits of Agreement analyses. Between-session reliability was high for both the T1 and the contrast-enhanced sequences. Specifically, the average CVs for translation were 4

Efficient theory of dipolar recoupling in solid-state nuclear magnetic resonance of rotating solids using Floquet-Magnus expansion: application on BABA and C7 radiofrequency pulse sequences.

Science.gov (United States)

Mananga, Eugene S; Reid, Alicia E; Charpentier, Thibault

2012-02-01

This article describes the use of an alternative expansion scheme called Floquet-Magnus expansion (FME) to study the dynamics of spin system in solid-state NMR. The main tool used to describe the effect of time-dependent interactions in NMR is the average Hamiltonian theory (AHT). However, some NMR experiments, such as sample rotation and pulse crafting, seem to be more conveniently described using the Floquet theory (FT). Here, we present the first report highlighting the basics of the Floquet-Magnus expansion (FME) scheme and hint at its application on recoupling sequences that excite more efficiently double-quantum coherences, namely BABA and C7 radiofrequency pulse sequences. The use of Λ(n)(t) functions available only in the FME scheme, allows the comparison of the efficiency of BABA and C7 sequences. Copyright © 2011 Elsevier Inc. All rights reserved.

Asymmetric rotator as a detector of monochromatic gravitational waves

International Nuclear Information System (INIS)

Gliner, Eh.B.; Mitrofanov, I.G.

1979-01-01

The interaction between a rotating asymmetric (principal moments of inertia are different) body with a gravitational wave is considered. A resonance rotational detector of monocrhomatic gravitational waves is proposed in which the turning due to the incident wave and the rotation which ensures resonance between the detector and wave correspond to different degrees of freedom. This significantly facilitates the creation of such detectors. The interference due to the gradient of the gravitational acceleration of the Earth and to rotation of the detector as a whole is estimated

Mental rotation of anthropoid hands: a chronometric study

Directory of Open Access Journals (Sweden)

L.G. Gawryszewski

2007-03-01

Full Text Available It has been shown that mental rotation of objects and human body parts is processed differently in the human brain. But what about body parts belonging to other primates? Does our brain process this information like any other object or does it instead maximize the structural similarities with our homologous body parts? We tried to answer this question by measuring the manual reaction time (MRT of human participants discriminating the handedness of drawings representing the hands of four anthropoid primates (orangutan, chimpanzee, gorilla, and human. Twenty-four right-handed volunteers (13 males and 11 females were instructed to judge the handedness of a hand drawing in palm view by pressing a left/right key. The orientation of hand drawings varied from 0º (fingers upwards to 90º lateral (fingers pointing away from the midline, 180º (fingers downwards and 90º medial (finger towards the midline. The results showed an effect of rotation angle (F(3, 69 = 19.57, P < 0.001, but not of hand identity, on MRTs. Moreover, for all hand drawings, a medial rotation elicited shorter MRTs than a lateral rotation (960 and 1169 ms, respectively, P < 0.05. This result has been previously observed for drawings of the human hand and related to biomechanical constraints of movement performance. Our findings indicate that anthropoid hands are essentially equivalent stimuli for handedness recognition. Since the task involves mentally simulating the posture and rotation of the hands, we wondered if "mirror neurons" could be involved in establishing the motor equivalence between the stimuli and the participants' own hands.

Uniqueness of exterior axisymmetric solution for a rotating charged body in the relativistic theory of gravitation

International Nuclear Information System (INIS)

Karabut, P.V.; Chugreev, Yu.V.

1989-01-01

The relativistic theory of gravitation (RTG), which is constructed on the basis of Minkowski spacetime, the geometrization principle, and the notion of the gravitational field var-phi mn as a physical field in the spirit of Faraday and Maxwell, explains all known gravitational experiments and gives a new prediction for the evolution of the universe, collapse, etc. The RTG determines the structure of the gravitational field as a field possessing spins 2 and 0 and all conservation laws for energy, momentum, and angular momentum. An exact solution of the complete simultaneous system of equations of the relativistic theory of gravitation and Maxwell's equations is found in the axisymmetric case for an electrically charged rotating body. The uniqueness of this solution is proved

Energy correlations for mixed rotational bands

International Nuclear Information System (INIS)

Doessing, T.

1985-01-01

A schematic model for the mixing of rotational bands above the yrast line in well deformed nuclei is considered. Many-particle configurations of a rotating mean field form basis bands, and these are subsequently mixed due to a two body residual interaction. The energy interval over which a basis band is spread out increases with increasing excitation energy above the yrast line. Conversely, the B(E2) matrix element for rotational decay out of one of the mixed band states is spread over an interval which is predicted to become more narrow with increasing excitation energy. Finally, the implication of band mixing for γ-ray energy correlations is briefly discussed. (orig.)

Fluidized Bed Reactor as Solid State Fermenter

Directory of Open Access Journals (Sweden)

Krishnaiah, K.

2005-01-01

Full Text Available Various reactors such as tray, packed bed, rotating drum can be used for solid-state fermentation. In this paper the possibility of fluidized bed reactor as solid-state fermenter is considered. The design parameters, which affect the performances are identified and discussed. This information, in general can be used in the design and the development of an efficient fluidized bed solid-state fermenter. However, the objective here is to develop fluidized bed solid-state fermenter for palm kernel cake conversion into enriched animal and poultry feed.

Cone beam CT-based set-up strategies with and without rotational correction for stereotactic body radiation therapy in the liver.

Science.gov (United States)

Bertholet, Jenny; Worm, Esben; Høyer, Morten; Poulsen, Per

2017-06-01

Accurate patient positioning is crucial in stereotactic body radiation therapy (SBRT) due to a high dose regimen. Cone-beam computed tomography (CBCT) is often used for patient positioning based on radio-opaque markers. We compared six CBCT-based set-up strategies with or without rotational correction. Twenty-nine patients with three implanted markers received 3-6 fraction liver SBRT. The markers were delineated on the mid-ventilation phase of a 4D-planning-CT. One pretreatment CBCT was acquired per fraction. Set-up strategy 1 used only translational correction based on manual marker match between the CBCT and planning CT. Set-up strategy 2 used automatic 6 degrees-of-freedom registration of the vertebrae closest to the target. The 3D marker trajectories were also extracted from the projections and the mean position of each marker was calculated and used for set-up strategies 3-6. Translational correction only was used for strategy 3. Translational and rotational corrections were used for strategies 4-6 with the rotation being either vertebrae based (strategy 4), or marker based and constrained to ±3° (strategy 5) or unconstrained (strategy 6). The resulting set-up error was calculated as the 3D root-mean-square set-up error of the three markers. The set-up error of the spinal cord was calculated for all strategies. The bony anatomy set-up (2) had the largest set-up error (5.8 mm). The marker-based set-up with unconstrained rotations (6) had the smallest set-up error (0.8 mm) but the largest spinal cord set-up error (12.1 mm). The marker-based set-up with translational correction only (3) or with bony anatomy rotational correction (4) had equivalent set-up error (1.3 mm) but rotational correction reduced the spinal cord set-up error from 4.1 mm to 3.5 mm. Marker-based set-up was substantially better than bony-anatomy set-up. Rotational correction may improve the set-up, but further investigations are required to determine the optimal correction

Theories of figures of celestial bodies

CERN Document Server

Jardetzky, Wenceslas S

2005-01-01

Everything in the universe rotates: the meteors, the asteroids, the planets and their satellites, the sun, the stars, the clusters and nebulae, even the galaxies themselves. The problem of the shape of a rotating body is therefore universal in astronomy. Its treatment in this book, which deals with the figures of equilibrium and distortions of rotating bodies, is full and rigorous.Suitable for upper-level undergraduates and graduate students, this text was written by a renowned researcher and educator who taught at Columbia University and served for many years as a research associate at the La

Biopolymer-based thermoplastic mixture for producing solid biodegradable shaped bodies and its photo degradation stability

Science.gov (United States)

Sulong, Nurulsaidatulsyida; Rus, Anika Zafiah M.

2013-12-01

In recent years, biopolymers with controllable lifetimes have become increasingly important for many applications in the areas of agriculture, biomedical implants and drug release, forestry, wild life conservation and waste management. Natural oils are considered to be the most important class of renewable sources. They can be obtained from naturally occurring plants, such as sunflower, cotton, linseed and palm oil. In Malaysia, palm oil is an inexpensive and commodity material. Biopolymer produced from palm oil (Bio-VOP) is a naturally occurring biodegradable polymer and readily available from agriculture. For packaging use however, Bio-VOP is not thermoplastic and its granular form is unsuitable for most uses in the plastics industry, mainly due to processing difficulties during extrusion or injection moulding. Thus, research workers have developed several methods to blend Bio-VOP appropriately for industrial uses. In particular, injections moulding processes, graft copolymerisation, and preparation of blends with thermoplastic polymers have been studied to produce solid biodegradable shaped bodies. HDPE was chosen as commercial thermoplastic materials and was added with 10% Bio-VOP for the preparation of solid biodegradable shaped bodies named as HD-VOP. The UV light exposure of HD-VOP at 12 minutes upon gives the highest strength of this material that is 17.6 MPa. The morphological structure of HD-VOP shows dwi structure surface fracture which is brittle and ductile properties.

Simulation of post-impact rotational changes through multi-dimensional parametrization

Science.gov (United States)

Gauchez, Damien; Souchay, Jean

2006-11-01

In this paper we propose firstly a full parametrization of an impact on a target body considered as ellipsoidal, including several geometrical parameters which are generally not included. Then we construct a more detailed and complete theoretical model of the rotational changes of the target body arising from a single impact, by taking into account the various parameters above. Secondly from these theoretical studies we carry out simulations of impacts and then we evaluate the influences of the various parameters on the rotational evolution of a specific target, in particular the angular speed of rotation and the direction of the axis of rotation. For that we consider two cases: in the first one, which we call accretion, the projectile is simply stuck to the target without a significant amount of ejected mass. In the second case, which we call craterization, the target body is eroded with formation of ejecta and a crater. The physical properties of the target are close to those of the Asteroid 21 Lutetia which Rosetta mission would fly in July 2010. We obtain quite different results according to the considered mode of impact (accretion or craterization): in the case of an impact with accretion the results are intuitively foreseeable whereas those corresponding to an impact with craterization are more difficult to interpret. Our work can be applied to obtain information on the rotational effects of an impact on a given target body with well constrained physical characteristics, in particular within the framework of the Don Quijote mission project.

Calculation of restricted rotational states in the methyl group

CERN Document Server

Ozaki, Y

2002-01-01

A methyl group attached to a molecule in the solid phase has a certain amount of hindrance in its rotational motion. The rotational potential can usually be expressed by the 3rd-order and the 6th-order terms of periodic functions. In the intermediate region with respect to the field strength and also the degree of mixing of two components, much variety appears in the structure of the rotational energy levels. The energy values correspond to the various molecular surroundings. The matrix elements are also derived, which yield the intensity of inelastic neutron scattering spectra. One example of calculated intensities is given. (orig.)

Diffusion relaxation times of nonequilibrium isolated small bodies and their solid phase ensembles to equilibrium states

Science.gov (United States)

Tovbin, Yu. K.

2017-08-01

The possibility of obtaining analytical estimates in a diffusion approximation of the times needed by nonequilibrium small bodies to relax to their equilibrium states based on knowledge of the mass transfer coefficient is considered. This coefficient is expressed as the product of the self-diffusion coefficient and the thermodynamic factor. A set of equations for the diffusion transport of mixture components is formulated, characteristic scales of the size of microheterogeneous phases are identified, and effective mass transfer coefficients are constructed for them. Allowing for the developed interface of coexisting and immiscible phases along with the porosity of solid phases is discussed. This approach can be applied to the diffusion equalization of concentrations of solid mixture components in many physicochemical systems: the mutual diffusion of components in multicomponent systems (alloys, semiconductors, solid mixtures of inert gases) and the mass transfer of an absorbed mobile component in the voids of a matrix consisting of slow components or a mixed composition of mobile and slow components (e.g., hydrogen in metals, oxygen in oxides, and the transfer of molecules through membranes of different natures, including polymeric).

Rapidly rotating general relativistic stars. Pt. 2. Differentially rotating polytropes

Energy Technology Data Exchange (ETDEWEB)

Komatsu, Hidemi [Tokyo Univ. (Japan). Faculty of Science; Eriguchi, Yoshiharu [Tokyo Univ. (Japan). Dept. of Astronomy; Hachisu, Izumi [Kyoto Univ. (Japan). Dept. of Aeronautical Engineering

1989-07-01

We have applied the numerical method which was developed for Newtonian gravity to general relativistic, differentially rotating bodies including ring-like structures. A number of equilibrium structures are obtained for two different polytropic indices N=1/2 and N=3/2, because the various proposed equations of state for the nuclear density region fall into the range N=1/2 to 3/2 from the viewpoint of its softness. (author).

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

Directory of Open Access Journals (Sweden)

S. V. Myamlin

2016-08-01

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

Niobium carbide synthesis by solid-gas reaction using a rotating cylinder reactor

International Nuclear Information System (INIS)

Fontes, F.A.O.; Gomes, K.K.P.; Oliveira, S.A.; Souza, C.P.; Sousa, J.F.; Rio Grande do Norte Univ., Natal, RN

2004-01-01

A rotating cylinder reactor was designed for the synthesis of niobium carbide powders at 1173 K. Niobium carbide, NbC, was prepared by carbothermal reduction starting from commercial niobium pentoxide powders. The reactor was heated using a custom-made, two-part, hinged, electric furnace with programmable temperature control. The design and operational details of the reactor are presented. The longitudinal temperature gradient inside the reactor was determined. Total reaction time was monitored by a gas chromatograph equipped with an FID detector for determination of methane concentrations. The results show that time of reaction depended on rotation speed. NbC was also prepared in a static-bed alumina reactor using the same conditions as in the previous case. The niobium carbide powders were characterized by X-ray diffraction and compared with commercially available products. Morphological, particle size distribution and surface area analyses were obtained using SEM, LDPS and BET, respectively. Therefore, the present study offers a significant technological contribution to the synthesis of NbC powders in a rotating cylinder reactor. (author)

THE ATHLETES’ BODY SHAPES THE ATHLETES’ MIND – NEW PERSPECTIVES ON MENTAL ROTATION PERFORMANCE IN ATHLETES

Directory of Open Access Journals (Sweden)

Thomas Heinen

2013-12-01

Full Text Available Mentally rotating the image of an object is one fundamental cognitive ability in humans. Recent theoretical developments and empirical evidences highlight the potential role of the sensory-motor system, when analysing and understanding mental rotation. Therefore, the purpose of this study was to investigate the role of specific sensory-motor experience on mental rotation performance in gymnasts. N = 40 male gymnasts with either clockwise or anticlockwise rotation preference in a forward twisting layout salto performed a psychometric mental rotation test with either rotation-preference congruent or rotation-preference incongruent stimuli. Results revealed that choice reaction times differed clearly as a function of Angular Rotation between the stimuli figures. Gymnasts who preferred a clockwise rotation preference showed faster choice reaction times when the rotation direction of the reference figure was clockwise, and vice versa. The results clearly support the notion, that mental rotation performance varies as a function of sensory-motor system characteristics between different people. It is concluded, that sensory-motor experience in a particular sport may facilitate cognitive processing of experience-congruent stimuli. This may be advantageous for situations in which people are engaged in observing sport performance (i.e., judges, coaches. This conclusion could furthermore contribute to the training of athletes from sports such as sky-diving, scuba-diving, and climbing, where losses of spatial orientation can be life-threatening.

Liquid-phase separation with the rotational particle separator

NARCIS (Netherlands)

Kemenade, van H.P.; Mondt, E.; Hendriks, A.J.A.M.; Verbeek, P.H.J.

2003-01-01

Recently, the rotational particle separator (RPS) was introduced as a new technique for separating solid and/or liquid particles of 0.1 m and larger from gases. In this patented technique the principles of centrifugation are exploited to enhance separation of small-sized phases and particulate

Collective rotations of active particles interacting with obstacles

Science.gov (United States)

Mokhtari, Zahra; Aspelmeier, Timo; Zippelius, Annette

2017-10-01

We consider active particles in a heterogeneous medium, modeled by static, random obstacles. In accordance with the known tendency of active particles to cluster, we observe accumulation and crystallization of active particles around the obstacles which serve as nucleation sites. In the limit of high activity, the crystals start to rotate spontaneously, resembling a rotating rigid body. We trace the occurrence of these oscillations to the enhanced attraction of particles whose orientation points along the rotational velocity as compared to those whose orientation points in the opposite direction.

Hydrogen and deuterium NMR of solids by magic-angle spinning

International Nuclear Information System (INIS)

Eckman, R.R.

1982-10-01

The nuclear magnetic resonance of solids has long been characterized by very large specral broadening which arises from internuclear dipole-dipole coupling or the nuclear electric quadrupole interaction. These couplings can obscure the smaller chemical shift interaction and make that information unavailable. Two important and difficult cases are that of hydrogen and deuterium. The development of cross polarization, heteronuclear radiofrequency decoupling, and coherent averaging of nuclear spin interactions has provided measurement of chemical shift tensors in solids. Recently, double quantum NMR and double quantum decoupling have led to measurement of deuterium and proton chemical shift tensors, respectively. A general problem of these experiments is the overlapping of the tensor powder pattern spectra of magnetically distinct sites which cannot be resolved. In this work, high resolution NMR of hydrogen and deuterium in solids is demonstrated. For both nuclei, the resonances are narrowed to obtain liquid-like isotropic spectra by high frequency rotation of the sample about an axis inclined at the magic angle, β/sub m/ = Arccos (3/sup -1/2/), with respect to the direction of the external magnetic field. For deuterium, the powder spectra were narrowed by over three orders of magnitude by magic angle rotation with precise control of β. A second approach was the observation of deuterium double quantum transitions under magic angle rotation. For hydrogen, magic angle rotation alone could be applied to obtain the isotropic spectrum when H/sub D/ was small. This often occurs naturally when the nuclei are semi-dilute or involved in internal motion. In the general case of large H/sub D/, isotropic spectra were obtained by dilution of 1 H with 2 H combined with magic angle rotation. The resolution obtained represents the practical limit for proton NMR of solids

Null result for violation of the equivalence principle with free-fall rotating gyroscopes

International Nuclear Information System (INIS)

Luo, J.; Zhou, Z.B.; Nie, Y.X.; Zhang, Y.Z.

2002-01-01

The differential acceleration between a rotating mechanical gyroscope and a nonrotating one is directly measured by using a double free-fall interferometer, and no apparent differential acceleration has been observed at the relative level of 2x10 -6 . It means that the equivalence principle is still valid for rotating extended bodies, i.e., the spin-gravity interaction between the extended bodies has not been observed at this level. Also, to the limit of our experimental sensitivity, there is no observed asymmetrical effect or antigravity of the rotating gyroscopes as reported by Hayasaka et al

General thermo-elastic solution of radially heterogeneous, spherically isotropic rotating sphere

Energy Technology Data Exchange (ETDEWEB)

Bayat, Yahya; EkhteraeiToussi, THamid [Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

2015-06-15

A thick walled rotating spherical object made of transversely isotropic functionally graded materials (FGMs) with general types of thermo-mechanical boundary conditions is studied. The thermo-mechanical governing equations consisting of decoupled thermal and mechanical equations are represented. The centrifugal body forces of the rotation are considered in the modeling phase. The unsymmetrical thermo-mechanical boundary conditions and rotational body forces are expressed in terms of the Legendre series. The series method is also implemented in the solution of the resulting equations. The solutions are checked with the known literature and FEM based solutions of ABAQUS software. The effects of anisotropy and heterogeneity are studied through the case studies and the results are represented in different figures. The newly developed series form solution is applicable to the rotating FGM spherical transversely isotropic vessels having nonsymmetrical thermo-mechanical boundary condition.

Left ventricular rigid body rotation in a diffuse large B-cell lymphoma patient with cardiac involvement: A case from the three-dimensional speckle-tracking echocardiographic MAGYAR-Path Study.

Science.gov (United States)

Földeák, Dóra; Kalapos, Anita; Domsik, Péter; Sinkó, Mária; Szeleczki, Nóra; Bagdi, Enikő; Krenács, László; Forster, Tamás; Borbényi, Zita; Nemes, Attila

2017-02-01

Secondary myocardial involvement by diffuse large B-cell lymphoma is a rare occurrence. Left ventricular (LV) twist is considered an essential part of LV function. In normal circumstances LV twist results from the movement of two orthogonally oriented muscular bands of a helical myocardial structure with consequent clockwise rotation of the base and counterclockwise rotation of the apex. Three-dimensional (3D) speckle-tracking echocardiography (3DSTE) has been found to be feasible for non-invasive 3D quantification of LV wall motion and rotational mechanics. The present report aimed to assess LV twisting motion in a patient with diffuse large B-cell lymphoma with positron emission tomography/computer tomography-proven cardiac involvement by 3DSTE. During 3DSTE, reduction in some segmental radial, longitudinal, circumferential, area and 3D LV strains were found. Apical and basal LV rotations were found to be in the same counterclockwise direction, confirming near absence of LV twist - so-called rigid body rotation. Copyright © 2016 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

Surface acoustic wave solid-state rotational micromotor

Science.gov (United States)

Shilton, Richie J.; Langelier, Sean M.; Friend, James R.; Yeo, Leslie Y.

2012-01-01

Surface acoustic waves (SAWs) are used to drive a 1 mm diameter rotor at speeds exceeding 9000 rpm and torque of nearly 5 nNm. Unlike recent high-speed SAW rotary motors, however, the present design does not require a fluid coupling layer but interestingly exploits adhesive stiction as an internal preload, a force usually undesirable at these scales; with additional preloads, smaller rotors can be propelled to 15 000 rpm. This solid-state motor has no moving parts except for the rotor and is sufficiently simple to allow integration into miniaturized drive systems for potential use in microfluidic diagnostics, optical switching and microrobotics.

Solid-state ring laser gyroscope

Science.gov (United States)

Schwartz, S.

The ring laser gyroscope is a rotation sensor used in most kinds of inertial navigation units. It usually consists in a ring cavity filled with a mixture of helium and neon, together with high-voltage pumping electrodes. The use of a gaseous gain medium, while resulting naturally in a stable bidirectional regime enabling rotation sensing, is however the main industrially limiting factor for the ring laser gyroscopes in terms of cost, reliability and lifetime. We study in this book the possibility of substituting for the gaseous gain medium a solid-state medium (diode-pumped Nd-YAG). For this, a theoretical and experimental overview of the lasing regimes of the solid-state ring laser is reported. We show that the bidirectional emission can be obtained thanks to a feedback loop acting on the states of polarization and inducing differential losses proportional to the difference of intensity between the counterpropagating modes. This leads to the achievement of a solid-state ring laser gyroscope, whose frequency response is modified by mode coupling effects. Several configurations, either mechanically or optically based, are then successively studied, with a view to improving the quality of this frequency response. In particular, vibration of the gain crystal along the longitudinal axis appears to be a very promising technique for reaching high inertial performances with a solid-state ring laser gyroscope. Gyrolaser à état solide. Le gyrolaser est un capteur de rotation utilisé dans la plupart des centrales de navigation inertielle. Dans sa forme usuelle, il est constitué d'une cavité laser en anneau remplie d'un mélange d'hélium et de néon pompé par des électrodes à haute tension. L'utilisation d'un milieu amplificateur gazeux, si elle permet de garantir naturellement le fonctionnement bidirectionnel stable nécessaire à la mesure des rotations, constitue en revanche la principale limitation industrielle des gyrolasers actuels en termes de coût, fiabilit

Upper shielding body in LMFBR type reactors

International Nuclear Information System (INIS)

Shoji, Koichi.

1986-01-01

Purpose: Preference is given to the strength and thermal insulation of a roof slab thereby ensuring axial size and improving the operationability upon inserting the control rod in the upper shielding body of LMFBR type reactors. Constitution: In an upper shielding body in which a large rotational plug is rotatably mounted to a circular hole formed at an eccentric position of a roof slab, while a small rotational plug is rotatably mounted to a circular hole disposed at an eccentric position of the large rotational plug and the reactor core upper mechanisms are supported on the small rotational plug, heat insulation layers are attached to the inside of the inner circumferential wall of the roof slab and the outer circumferential wall of the large rotational plug. By attaching the heat insulation layers, the heat conduction between the roof slab and the large rotational plug can be suppressed remarkably, by which occurrence of specific heat pass or local generation of large thermal stresses can be avoided even if difference is resulted to the temperature distribution between them. In this way, functions taking advantage of respective features of the roof slab and the small rotational plug can be obtained to achieve the purpose. (Kamimura, M.)

Evolution of rotating stars. III. Predicted surface rotation velocities for stars which conserve total angular momentum

International Nuclear Information System (INIS)

Endal, A.S.; Sofia, S.

1979-01-01

Predicted surface rotation velocities are presented for Population I stars at 10, 7, 5, 3, and 1.5M/sub sun/. The surface velocities have been computed for three different cases of angular momentum redistribution: no radial redistribution (rotation on decoupled shells), complete redistribution (rigid-body rotation), and partial redistribution as predicted by detailed consideration of circulation currents in rotation stars. The velocities for these cases are compared to each other and to observed stellar rotation rates (upsilon sin i).Near the main sequence, rotational effects can substantially reduce the moment of inertia of a star, so nonrotating models consistently underestimate the expected velocities for evolving stars. The magnitude of these effects is sufficient to explain the large numbers of Be stars and, perhaps, to explain the bimodal distribution of velocities observed for the O stars.On the red giant branch, angular momentum redistribution reduces the surface velocity by a factor of 2 or more, relative to the velocity expected for no radial redistribution. This removes the discrepancy between predicted and observed rotation rates for the K giants and makes it unlikely that these stars lose significant amounts of angular momentum by stellar winds. Our calculations indicate that improved observations (by the Fourier-transform technique) of the red giants in the Hyades cluster can be used to determine how angular momentum is redistributed by convection

A linearized system describing stationary incompressible viscous flow around rotating and translating bodies: improved decay estimates of the velocity and its gradient

Czech Academy of Sciences Publication Activity Database

Deuring, P.; Kračmar, S.; Nečasová, Šárka

2011-01-01

Roč. 2011, - (2011), s. 351-361 ISSN 1078-0947. [8th AIMS International Conference. Dresden, 25.05.2010-28.05.2010] R&D Projects: GA AV ČR IAA100190804; GA ČR(CZ) GAP201/11/1304 Institutional research plan: CEZ:AV0Z10190503 Keywords : viscous incompressible flow * rotating body * fundamental solution Subject RIV: BA - General Mathematics Impact factor: 0.913, year: 2011 http://aimsciences.org/journals/displayArticlesnew.jsp?paperID=6978

Investigation of scattering processes in quantum few-body systems involving long-range interaction by the complex-rotation method

International Nuclear Information System (INIS)

Volkov, M. V.; Elander, N.; Yakovlev, S. L.; Yarevsky, E. A.

2013-01-01

The complex-rotation method adapted to solving the multichannel scattering problem in the two-body system where the interaction potential contains the long-range Coulomb components is described. The scattering problem is reformulated as the problem of solving a nonhomogeneous Schrödinger equation in which the nonhomogeneous term involves a Coulomb potential cut off at large distances. The incident wave appearing in the nonhomogeneous term is a solution of the Schrödinger equation with longrange Coulomb interaction. This formulation is free from approximations associated with a direct cutoff of Coulomb interaction at large distances. The efficiency of this formalism is demonstrated by considering the example of solving scattering problems in the α-α and p-p systems.

Chemical reaction effects on unsteady MHD free convective flow in a rotating porous medium with mass transfer

Directory of Open Access Journals (Sweden)

Govindarajan Arunachalam

2014-01-01

Full Text Available An investigation of unsteady MHD free convective flow and mass transfer during the motion of a viscous incompressible fluid through a porous medium, bounded by an infinite vertical porous surface, in a rotating system is presented. The porous plane surface and the porous medium are assumed to rotate in a solid body rotation. The vertical surface is subjected to uniform constant suction perpendicular to it and the temperature at this surface fluctuates in time about a non-zero constant mean. Analytical expressions for the velocity, temperature and concentration fields are obtained using the perturbation technique. The effects of R (rotation parameter, k0 (permeability parameter, M (Hartmann number and w (frequency parameter on the flow characteristics are discussed. It is observed that the primary velocity component decreases with the increase in either of the rotation parameter R, the permeability parameter k0, or the Hartmann number M. It is also noted that the primary skin friction increases whenever there is an increase in the Grashof number Gr or the modified Grashof number Gm. It is clear that the heat transfer coefficient in terms of the Nusselt number decreases in the case of both air and water when there is an increase in the Hartmann number M. It is observed that the magnitude of the secondary velocity profiles increases whenever there is an increase in either of the Grashof number or the modified Grashof number for mass transfer or the permeability of the porous media. Concentration profiles decreases with an increase in the Schmidt number.

Removal of batteries from solid waste using trommel separation.

Science.gov (United States)

Lau, S T; Cheung, W H; Kwong, C K; Wan, C P; Choy, K K H; Leung, C C; Porter, J F; Hui, C W; Mc Kay, G

2005-01-01

This paper describes the design and testing of a trommel for separation of batteries from solid waste. A trommel is a cylindrical separation device that rotates and performs size separation. It has also been used in areas such as municipal solid waste (MSW) processing, classifying construction and demolition debris, screening mass-burn incinerator ash and compost processing. A trommel has been designed based on size separation to separate household batteries from solid waste, which can then be used as feedstock for alternative applications of solid waste combustion, particularly where the metal content of the product is also a critical parameter, such as the Co-Co process for integrated cement and power production. This trommel has been tested with batches of university office and restaurant wastes against various factors. The recovery efficiency of batteries increases with decreasing inclination angle of the trommel and decreasing rotational speed. A physical characterization of the university solid waste has been performed with a 20-kg sample of the tested waste. It was found that there is a trend of decreasing recovery of batteries with increasing paper composition, and a trend of increasing recovery of batteries with increasing organic materials composition.

One common structural peculiarity of the Solar system bodies including the star, planets, satellites and resulting from their globes rotation

Science.gov (United States)

Kochemasov, G. G.

2008-09-01

Often observed a sensible difference in appearance and structure between tropical and extra-tropical zones of various heavenly bodies including rocky and gas planets, satellites and Sun compels to look for a common reason of such phenomenon. All bodies rotate and their spherical shape makes zones at different latitudes to have differing angular momenta as a distance to the rotation axis diminishes gradually from the equator to the poles (this is felt particularly when one launches rockets into space -preferable more cheap launches are from the equatorial regions - Kourou is better than Baikonur). One of remarkable changes occurs at tropics. As a single rotating planetary body tends to have angular momenta of its tectonic blocks equilibrated it starts mechanisms leveling this basic physical property. At tropical zones (bulged also due to the rotation ellipsoid) the outer shell - crust as a consequence tends to be destroyed, sunk, subsided and shrunk; a density of crust material changes; the atmosphere reacts changing chemistry and structure; in terrestrial anthroposphere man looses its mass and stature. But according to the Le Chatelier rule mechanisms with an opposing tendency also begin to act. At Earth the wide planetary long tropical zone is marked by destruction of the crust. It is demonstrated by development of numerous islands of the Malay Archipelago (the Sunda Isls., Maluku Isls, Philippines) between the Southeastern Asia and Australia. In Africa and South America huge depressions of the Congo and Amazon Rivers develops where the Archean crust is subsided to depths of more than 2 km. In the Pacific along the equator numerous islands of Micronesia occur. Subsidence of the basaltic oceanic crust is followed by an intensive folding and faulting of basalt and sedimentary layers (Fig. 1) as a larger mass must be held by a smaller space (a planetary radius is diminished). The central Atlantic is very demonstrative in this sense suffering huge transform fault

A survey of the theory of the Earth's rotation

Science.gov (United States)

Cannon, W. H.

1981-01-01

The theory of the Earth's rotation and the geophysical phenomena affecting it is examined. First principles are reviewed and the problem of polar motion and UT1 variations is formulated in considerable generality and detail. The effects of Earth deformations and the solid Earth tides are analyzed.

Solid-Phase Extraction Strategies to Surmount Body Fluid Sample Complexity in High-Throughput Mass Spectrometry-Based Proteomics

Science.gov (United States)

Bladergroen, Marco R.; van der Burgt, Yuri E. M.

2015-01-01

For large-scale and standardized applications in mass spectrometry- (MS-) based proteomics automation of each step is essential. Here we present high-throughput sample preparation solutions for balancing the speed of current MS-acquisitions and the time needed for analytical workup of body fluids. The discussed workflows reduce body fluid sample complexity and apply for both bottom-up proteomics experiments and top-down protein characterization approaches. Various sample preparation methods that involve solid-phase extraction (SPE) including affinity enrichment strategies have been automated. Obtained peptide and protein fractions can be mass analyzed by direct infusion into an electrospray ionization (ESI) source or by means of matrix-assisted laser desorption ionization (MALDI) without further need of time-consuming liquid chromatography (LC) separations. PMID:25692071

The motion of a compressible viscous fluid around rotating body

Czech Academy of Sciences Publication Activity Database

Kračmar, S.; Nečasová, Šárka; Novotný, A.

2014-01-01

Roč. 60, č. 1 (2014), s. 189-208 ISSN 0430-3202 R&D Projects: GA ČR(CZ) GAP201/11/1304 Institutional support: RVO:67985840 Keywords : compressible fluids * rotating fluids * Navier-Stokes equations Subject RIV: BA - General Mathematics http://link.springer.com/article/10.1007%2Fs11565-014-0212-5

The Effect of Fluid and Solid Properties on the Auxetic Behavior of Porous Materials Having Rock-like Microstructures

Science.gov (United States)

Wollner, U.; Vanorio, T.; Kiss, A. M.

2017-12-01

Materials with a negative Poisson's Ratio (PR), known as auxetics, exhibit the counterintuitive behavior of becoming wider when uniaxially stretched and thinner when compressed. Though negative PR is characteristic of polymer foams or cellular solids, tight as well as highly porous rocks have also been reported to exhibit a negative Poisson's ratio, both from dynamic (PRd) and static measurements. We propose a novel auxetic structure based on pore-space configuration observed in rocks. First, we performed 2D and 3D imaging of a pumice and tight basalt to analyze their rock microstructure as well as similarities to natural structures of auxetic materials - e.g., cork. Based on these analyses, we developed a theoretical auxetic 3D model consisting of rotating rigid bodies having pore configurations similar to those observed in rocks. To alleviate the mechanical assumption of rotating bodies, the theoretical model was modified to include crack-like features being represented by intersecting, elliptic cylinders. We then used a 3D printer to create a physical version of the modified model, whose PRd was tested. We also numerically explored how the compressibility of fluids located in the pore-space of the modified model as well as how the elastic properties of the material from which the model is made of affect its auxetic behavior. We conclude that for a porous medium composed of a single material saturated with a single fluid (a) the more compliant the fluid is and (b) the lower the PR of the solid material, the lower the PR value of the composite material.

Biases in the perception of self-motion during whole-body acceleration and deceleration

Directory of Open Access Journals (Sweden)

Luc eTremblay

2013-12-01

Full Text Available Several studies have investigated whether vestibular signals can be processed to determine the magnitude of passive body motions. Many of them required subjects to report their perceived displacements offline, i.e. after being submitted to passive displacements. Here, we used a protocol that allowed us to complement these results by asking subjects to report their introspective estimation of their displacement continuously, i.e. during the ongoing body rotation. To this end, participants rotated the handle of a manipulandum around a vertical axis to indicate their perceived change of angular position in space at the same time as they were passively rotated in the dark. The rotation acceleration (Acc and deceleration (Dec lasted either 1.5 s (peak of 60 deg/s2, referred to as being "High" or 3 s (peak of 33 deg/s2, referred to as being "Low". The participants were rotated either counter-clockwise or clockwise, and all combinations of acceleration and deceleration were tested (i.e., AccLow-DecLow; AccLow-DecHigh; AccHigh-DecLow; AccHigh-DecHigh. The participants' perception of body rotation was assessed by computing the gain, i.e. ratio between the amplitude of the perceived rotations (as measured by the rotating manipulandum’s handle and the amplitude of the actual chair rotations. The gain was measured at the end of the rotations, and was also computed separately for the acceleration and deceleration phases. Three salient findings resulted from this experiment: i the gain was much greater during body acceleration than during body deceleration, ii the gain was greater during High compared to Low accelerations and iii the gain measured during the deceleration was influenced by the preceding acceleration (i.e., Low or High. These different effects of the angular stimuli on the perception of body motion can be interpreted in relation to the consequences of body acceleration and deceleration on the vestibular system and on higher-order cognitive

Dissipative N-body simulations of the formation of single galaxies in a cold dark-matter cosmology

International Nuclear Information System (INIS)

Ewell, M.W. Jr.

1988-01-01

The details of an N-body code designed specifically to study the collapse of a single protogalaxy are presented. This code uses a spherical harmonic expansion to model the gravity and a sticky-particle algorithm to model the gas physics. It includes external tides and cosmologically realistic boundary conditions. The results of twelve simulations using this code are given. The initial conditions for these runs use mean-density profiles and r.m.s. quadrupoles and tides taken from the CDM power spectrum. The simulations start when the center of the perturbation first goes nonlinear, and continue until a redshift Z ∼ 1-2. The resulting rotation curves are approximately flat out to 100 kpc, but do show some structure. The circular velocity is 200 km/sec around a 3σ peak. The final systems have λ approx-equal .03. The angular momentum per unit mass of the baryons implies disk scale lengths of 1-3 kpc. The tidal forces are strong enough to profoundly influence the collapse geometry. In particular, the usual assumption, that tidal torques produce a system approximately in solid-body rotation, is shown to be seriously in error

Floating and sinking: the imprint of massive scalars around rotating black holes.

Science.gov (United States)

Cardoso, Vitor; Chakrabarti, Sayan; Pani, Paolo; Berti, Emanuele; Gualtieri, Leonardo

2011-12-09

We study the coupling of massive scalar fields to matter in orbit around rotating black holes. It is generally expected that orbiting bodies will lose energy in gravitational waves, slowly inspiraling into the black hole. Instead, we show that the coupling of the field to matter leads to a surprising effect: because of superradiance, matter can hover into "floating orbits" for which the net gravitational energy loss at infinity is entirely provided by the black hole's rotational energy. Orbiting bodies remain floating until they extract sufficient angular momentum from the black hole, or until perturbations or nonlinear effects disrupt the orbit. For slowly rotating and nonrotating black holes floating orbits are unlikely to exist, but resonances at orbital frequencies corresponding to quasibound states of the scalar field can speed up the inspiral, so that the orbiting body sinks. These effects could be a smoking gun of deviations from general relativity.

The tumbling rotational state of 1I/`Oumuamua

Science.gov (United States)

Fraser, Wesley C.; Pravec, Petr; Fitzsimmons, Alan; Lacerda, Pedro; Bannister, Michele T.; Snodgrass, Colin; Smolić, Igor

2018-05-01

The discovery1 of 1I/2017 U1 (1I/`Oumuamua) has provided the first glimpse of a planetesimal born in another planetary system. This interloper exhibits a variable colour within a range that is broadly consistent with local small bodies, such as the P- and D-type asteroids, Jupiter Trojans and dynamically excited Kuiper belt objects2-7. 1I/`Oumuamua appears unusually elongated in shape, with an axial ratio exceeding 5:1 (refs 1,4,5,8). Rotation period estimates are inconsistent and varied, with reported values between 6.9 and 8.3 h (refs 4-6,9). Here, we analyse all the available optical photometry data reported to date. No single rotation period can explain the exhibited brightness variations. Rather, 1I/`Oumuamua appears to be in an excited rotational state undergoing non-principal axis rotation, or tumbling. A satisfactory solution has apparent lightcurve frequencies of 0.135 and 0.126 h-1 and implies a longest-to-shortest axis ratio of ≳5:1, although the available data are insufficient to uniquely constrain the true frequencies and shape. Assuming a body that responds to non-principal axis rotation in a similar manner to Solar System asteroids and comets, the timescale to damp 1I/`Oumuamua's tumbling is at least one billion years. 1I/`Oumuamua was probably set tumbling within its parent planetary system and will remain tumbling well after it has left ours.

Weird muonium diffusion in solid xenon

International Nuclear Information System (INIS)

Storchak, V.G.; Kirillov, B.F.; Pirogov, A.V.

1992-09-01

Muon and muonium spin rotation and relaxation parameters were studied in liquid and solid xenon. The small diamagnetic fraction (∼ 10%) observed in condensed xenon is believed to be Xeμ + . The muonium hyperfine frequency was measured for the first time in liquid Xe and was found to be in agreement with the vacuum value. A nonmonotonic temperature dependence of the muonium relaxation rate probably indicates that muonium diffusion in solid Xe is of quantum nature. 16 refs., 3 figs

Numerical study on the rotation of an elastic rod in a viscous fluid using an immersed boundary method

International Nuclear Information System (INIS)

Maniyeri, Ranjith; Kang, Sang Mo

2012-01-01

We present a three dimensional computational model based on an immersed boundary (IB) method to study the hydrodynamic features of a solid flexible cylindrical rod in a viscous fluid driven at one side by a tiny motor. The elastic rod is modelled by a number of circular cross-sections with twelve IB points on each cross-section. Three types of elastic links are created from each IB point to obtain an elastic network model of the rod and the first cross-section is modelled as the motor part. The elastic forces are computed based on an elastic energy approach and the motor forces are obtained from the applied angular frequency of rotation of the motor. The Stokes equations governing the fluid are solved on a staggered Cartesian grid system using the fractional-step based finite-volume method. Numerical simulations are performed to demonstrate the three dynamical stages of rod motion- twirling, whirling and overwhirling for different rotational frequency of the motor. It is revealed that for low rotational frequencies, the rod undergoes stable rigid body motion known as twirling. For high rotational frequencies of the motor, it is observed that the rod initially undergoes whirling motion and attains an unstable helical shape. Further, it is noticed that a discontinuous shape transition occurs for the rod and it folds back on itself. This unstable motion is referred to as overwhirling. It is also found that there exists a critical value of angular frequency of rotation of the motor below which the rod is subjected to twirling motion and above which it undergoes overwhirling motion

Long-Period Tidal Variations of the Earth's Rotation Rate

Science.gov (United States)

Desai, S.; Gross, R.; Wahr, J.

1999-01-01

Long-period tidal variations of the Earth's rotation rate are caused by the redistribution of mass associated with the respective elastic solid Earth tides, the ocean tide heights, and the anelasticity of the Earth's mantle, and by the relative angular momentum associated with the long-period ocean tide currents.

Rotation of the bulge components of barred galaxies

International Nuclear Information System (INIS)

Kormendy, J.

1982-01-01

Stellar rotation and velocity-dispersion measurements are presented for the bulge components of the SBO galaxies NGC 1023, 2859, 2950, 4340, 4371, and 7743. The kinematics of nine SB bulges with data available are compared with bulges of unbarred galaxies studied by Kormendy and Illingworth. All of the SB bulges are found to rotate at least as rapidly as oblate-spheroid dynamical models which are flattened by rotation. This result confirms the conclusion of Kormendy and Illingworth that bulges rotate very rapidly. Six SB bulges found by Kormendy and Koo to be triaxial rotate even more rapidly than the oblate models. In this respect, they resemble published n-body models of bars. That is, triaxial bulges are dynamically like bars and unlike elliptical galaxies, which are also believed to be triaxial, but which rotate slowly. Measured velocity anisotropies are found to be consistent with these conclusions. Two ordinary bulges whose rotation is well described by isotropic modes have a ratio of radial to azimuthal velocity dispersion of sigma/sub r//sigma/sub theta/ = 0.96 +- 0.03. In contrast, the triaxial bulge of NGC 3945, which rotates much faster than the isotropic models, has sigma/sub r//sigma/sub theta/ approx.1.31 +- 0.06. This is similar to the degree of anisotropy, sigma/sub r//sigma/sub theta/approx.1.21 +- 0.03, found in a recent n-body bar model by Hohl and Zang. Altogether the kinematic observations imply the triaxial bulges are more disklike than SA bulges. They appear to have been formed with more dissipation than ordinary bulges. These results are consistent with the hypothesis that part of the bulge in many SB galaxies consists of disk material (i.e., gas) which has been transported to the center by the bar. The resulting star formation may produce a very centrally concentrated light distribution which resembles a bulge but which has dislike dynamics

Simulating Lahars Using A Rotating Drum

Science.gov (United States)

Neather, Adam; Lube, Gert; Jones, Jim; Cronin, Shane

2014-05-01

A large (0.5 m in diameter, 0.15 m wide) rotating drum is used to investigate the erosion and deposition mechanics of lahars. To systematically simulate the conditions occurring in natural mass flows our experimental setup differs from the common rotating drum employed in industrial/engineering studies. Natural materials with their typical friction properties are used, as opposed to the frequently employed spherical glass beads; the drum is completely water-proof, so solid/air and solid/liquid mixtures can be investigated; the drum velocity and acceleration can be precisely controlled using a software interface to a micro-controller, allowing for the study of steady, unsteady and intermediate flow regimes. The drum has a toughened glass door, allowing high-resolution, high-speed video recording of the material inside. Vector maps of the velocities involved in the flows are obtained using particle image velocimetry (PIV). The changes in velocity direction and/or magnitude are used to locate the primary internal boundaries between layers of opposite flow direction, as well as secondary interfaces between shear layers. A range of variables can be measured: thickness and number of layers; the curvature of the free surface; frequency of avalanching; position of the centre of mass of the material; and the velocity profiles of the flowing material. Experiments to date have focussed on dry materials, and have had a fill factor of approximately 0.3. Combining these measured variables allows us to derive additional data of interest, such as mass and momentum flux. It is these fluxes that we propose will allow insight into the erosion/deposition mechanics of a lahar. A number of conclusions can be drawn to date. A primary interface separates flowing and passive region (this interface has been identified in previous studies). As well as the primary interface, the flowing layer separates into individual shear layers, with individual erosion/deposition and flow histories. This

Rotations in a Vertebrate Setting

Science.gov (United States)

McCollum, Gin

2003-05-01

Rotational movements of the head are often considered to be measured in a single three dimensional coordinate system implemented by the semicircular canals of the vestibular system of the inner ear. However, the vertebrate body -- including the nervous system -- obeys rectangular symmetries alien to rotation groups. At best, nervous systems mimic the physical rotation group in a fragmented way, only partially reintegrating physical movements in whole organism responses. The vestibular canal reference frame is widely used in nervous systems, for example by eye movements. It is used to some extent even in the cerebrum, as evidenced by the remission of hemineglect -- in which half of space is ignored -- when the vestibular system is stimulated. However, reintegration of space by the organism remains incomplete. For example, compensatory eye movements (which in most cases aid visual fixation) may disagree with conscious self-motion perception. In addition, movement-induced nausea, illusions, and cue-free perceptions demonstrate symmetry breaking or incomplete spatial symmetries. As part of a long-term project to investigate rotation groups in nervous systems, we have analyzed the symmetry group of a primary vestibulo-spinal projection.

On selection rules in vibrational and rotational molecular spectroscopy

International Nuclear Information System (INIS)

Guichardet, A.

1986-01-01

The aim of this work is a rigorous proof of the Selection Rules in Molecular Spectroscopy (Vibration and Rotation). To get this we give mathematically rigorous definitions of the (tensor) transition operators, in this case the electric dipole moment; this is done, firstly by considering the molecule as a set of point atomic kernels performing arbitrary motions, secondly by limiting ourselves either to infinitesimal vibration motions, or to arbitrary rotation motions. Then the selection rules follow from an abstract formulation of the Wigner-Eckart theorem. In a last paragraph we discuss the problem of separating vibration and rotation motions; very simple ideas from Differential Geometry, linked with the ''slice theorem'', allow us to define the relative speeds, the solid motions speeds, the Coriolis energies and the moving Eckart frames [fr

Label-acquired magnetorotation for biosensing: An asynchronous rotation assay

International Nuclear Information System (INIS)

Hecht, Ariel; Kinnunen, Paivo; McNaughton, Brandon; Kopelman, Raoul

2011-01-01

This paper presents a novel application of magnetic particles for biosensing, called label-acquired magnetorotation (LAM). This method is based on a combination of the traditional sandwich assay format with the asynchronous magnetic bead rotation (AMBR) method. In label-acquired magnetorotation, an analyte facilitates the binding of a magnetic label bead to a nonmagnetic solid phase sphere, forming a sandwich complex. The sandwich complex is then placed in a rotating magnetic field, where the rotational frequency of the sandwich complex is a function of the amount of analyte attached to the surface of the sphere. Here, we use streptavidin-coated beads and biotin-coated particles as analyte mimics, to be replaced by proteins and other biological targets in future work. We show this sensing method to have a dynamic range of two orders of magnitude.

Multibody dynamic analysis using a rotation-free shell element with corotational frame

Science.gov (United States)

Shi, Jiabei; Liu, Zhuyong; Hong, Jiazhen

2018-03-01

Rotation-free shell formulation is a simple and effective method to model a shell with large deformation. Moreover, it can be compatible with the existing theories of finite element method. However, a rotation-free shell is seldom employed in multibody systems. Using a derivative of rigid body motion, an efficient nonlinear shell model is proposed based on the rotation-free shell element and corotational frame. The bending and membrane strains of the shell have been simplified by isolating deformational displacements from the detailed description of rigid body motion. The consistent stiffness matrix can be obtained easily in this form of shell model. To model the multibody system consisting of the presented shells, joint kinematic constraints including translational and rotational constraints are deduced in the context of geometric nonlinear rotation-free element. A simple node-to-surface contact discretization and penalty method are adopted for contacts between shells. A series of analyses for multibody system dynamics are presented to validate the proposed formulation. Furthermore, the deployment of a large scaled solar array is presented to verify the comprehensive performance of the nonlinear shell model.

Volatiles from solids

Energy Technology Data Exchange (ETDEWEB)

Loughrey, C T

1939-08-24

To remove volatiles from solids, such as oil shale, gases, and/or vapours are passed through a mass of the materials, the vapours and gases separated, and the vapours condensed. The volatile-containing solid materials are fed to a retort, and a shaft is driven to rotate an impeller so as to displace the liquid and create a vortex tube, which draws in gas from the atmosphere through an intake, twyer, interstices in the material in the retort, a conduit, chamber, tubes, another chamber and cylinder. This gas is carried outwardly and upwardly by the vortices in the liquid and is carried to discharge through three conduits. The vapours entrained by the gas are part condensed in the liquid and the remainder directed to a condenser. Steam may be delivered to the twyer through a nozzle of a pipe, with or without air, and combustible hydrocarbon fuel may be fed through the burner nozzle or solid fuel may be directed from feeder and combusted in the twyer.

Mixed quantum/classical theory of rotationally and vibrationally inelastic scattering in space-fixed and body-fixed reference frames.

Science.gov (United States)

Semenov, Alexander; Babikov, Dmitri

2013-11-07

We formulated the mixed quantum/classical theory for rotationally and vibrationally inelastic scattering process in the diatomic molecule + atom system. Two versions of theory are presented, first in the space-fixed and second in the body-fixed reference frame. First version is easy to derive and the resultant equations of motion are transparent, but the state-to-state transition matrix is complex-valued and dense. Such calculations may be computationally demanding for heavier molecules and/or higher temperatures, when the number of accessible channels becomes large. In contrast, the second version of theory requires some tedious derivations and the final equations of motion are rather complicated (not particularly intuitive). However, the state-to-state transitions are driven by real-valued sparse matrixes of much smaller size. Thus, this formulation is the method of choice from the computational point of view, while the space-fixed formulation can serve as a test of the body-fixed equations of motion, and the code. Rigorous numerical tests were carried out for a model system to ensure that all equations, matrixes, and computer codes in both formulations are correct.

Mixed quantum/classical theory of rotationally and vibrationally inelastic scattering in space-fixed and body-fixed reference frames

International Nuclear Information System (INIS)

Semenov, Alexander; Babikov, Dmitri

2013-01-01

We formulated the mixed quantum/classical theory for rotationally and vibrationally inelastic scattering process in the diatomic molecule + atom system. Two versions of theory are presented, first in the space-fixed and second in the body-fixed reference frame. First version is easy to derive and the resultant equations of motion are transparent, but the state-to-state transition matrix is complex-valued and dense. Such calculations may be computationally demanding for heavier molecules and/or higher temperatures, when the number of accessible channels becomes large. In contrast, the second version of theory requires some tedious derivations and the final equations of motion are rather complicated (not particularly intuitive). However, the state-to-state transitions are driven by real-valued sparse matrixes of much smaller size. Thus, this formulation is the method of choice from the computational point of view, while the space-fixed formulation can serve as a test of the body-fixed equations of motion, and the code. Rigorous numerical tests were carried out for a model system to ensure that all equations, matrixes, and computer codes in both formulations are correct

Effect of aflatoxin ingestion on total body water (T OH3 - space), total body solids A KD on some physiological and reproductive characteristics of male albino rats

International Nuclear Information System (INIS)

Nowar, M.S.; Eldarawany, A.A.; Habeeb, A.A.

1992-01-01

This investigation aimed to study the effects of aflatoxins B 1 +G 1 mixture mainly on total body water (TBW) and on total body solids (TBS) of male albino rats. Some blood components and some reproductive characteristic were also taken into consideration. Two groups, each of 8 male rats were fed the same ration. Rats of one group had been individually ingested daily with a dose of 22 μg B 1 plus 22 μg G 1 for 15 successive weeks. The obtained results showed that aflatoxin administration caused: 1- A decrease in final body weight (FBW), TBW (P<0.01) and TBS (P<0.05). 2- A decrease in serum total proteins (P<0.01), albumin (P<0.05), globulin (P<0.05), glucose (P<0.05) and increase in serum cholesterol, GOT and GPT (P<0.05) activities. 3- A decrease in each of the number of effective matings of males and delivery percentages of females mated with treated males.1 tab

Self-rotations in simulated microgravity: performance effects of strategy training.

Science.gov (United States)

Stirling, Leia; Newman, Dava; Willcox, Karen

2009-01-01

This research studies reorientation methodologies in a simulated microgravity environment using an experimental framework to reduce astronaut adaptation time and provide for a safety countermeasure during extravehicular activity. There were 20 subjects (10 men, 10 women, mean age of 23.6 +/- 3.5) who were divided into 2 groups, fully trained and minimally trained, which determined the amount of motion strategy training received. Subjects performed a total of 48 rotations about their pitch, roll, and yaw axes in a suspension system that simulated microgravity. In each trial subjects either rotated 90 degrees in pitch, 90 degrees in roll, or 180 degrees in yaw. Experimental measures include subject coordination, performance time, cognitive workload assessments, and qualitative motion control strategies. Subjects in the fully trained group had better initial performance with respect to performance time and workload scores for the pitch and yaw rotations. Further, trained subjects reached a steady-state performance time in fewer trials than those with minimal training. The subjects with minimal training tended to use motions that were common in an Earth environment since no technique was provided. For roll rotations they developed motions that would have led to significant off-axis (pitch and yaw) rotations in a true microgravity environment. We have shown that certain body axes are easier to rotate about than others and that fully trained subjects had an easier time performing the body rotations than the minimally trained subjects. This study has provided the groundwork for the development of an astronaut motion-control training program.

Dynamic Models of Instruments Using Rotating Unbalanced Masses

Science.gov (United States)

Hung, John Y.; Gallaspy, Jason M.; Bishop, Carlee A.

1998-01-01

The motion of telescopes, satellites, and other flight bodies have been controlled by various means in the past. For example, gimbal mounted devices can use electric motors to produce pointing and scanning motions. Reaction wheels, control moment gyros, and propellant-charged reaction jets are other technologies that have also been used. Each of these methods has its advantages, but all actuator systems used in a flight environment face the challenges of minimizing weight, reducing energy consumption, and maximizing reliability. Recently, Polites invented and patented the Rotating Unbalanced Mass (RUM) device as a means for generation scanning motion on flight experiments. RUM devices together with traditional servomechanisms have been successfully used to generate various scanning motions: linear, raster, and circular. The basic principle can be described: A RUM rotating at constant angular velocity exerts a cyclic centrifugal force on the instrument or main body, thus producing a periodic scanning motion. A system of RUM devices exerts no reaction forces on the main body, requires very little energy to rotate the RUMS, and is simple to construct. These are significant advantages over electric motors, reaction wheels, and control moment gyroscopes. Although the RUM device very easily produces scanning motion, an auxiliary control system has been required to maintain the proper orientation, or pointing of the main body. It has been suggested that RUM devices can be used to control pointing dynamics, as well as generate the desired periodic scanning motion. The idea is that the RUM velocity will not be kept constant, but will vary over the period of one RUM rotation. The thought is that the changing angular velocity produces a centrifugal force having time-varying magnitude and direction. The scope of this ongoing research project is to study the pointing control concept, and recommend a direction of study for advanced pointing control using only RUM devices. This

Dynamic ocean-tide effects on Earth's rotation

Science.gov (United States)

Dickman, S. R.

1993-01-01

This article develops 'broad-band' Liouville equations which are capable of determining the effects on the rotation of the Earth of a periodic excitation even at frequencies as high as semi-diurnal; these equations are then used to predict the rotational effects of altimetric, numerical and 32-constituent spherical harmonic ocean-tide models. The rotational model includes a frequency-dependent decoupled core, the effects of which are especially marked near retrograde diurnal frequencies; and a fully dynamic oceanic response, whose effects appear to be minor despite significant frequency dependence. The model also includes solid-earth effects which are frequency dependent as the result of both anelasticity at long periods and the fluid-core resonance at nearly diurnal periods. The effects of both tidal inertia and relative angular momentum on Earth rotation (polar motion, length of day, 'nutation' and Universal Time) are presented for 32 long- and short-period ocean tides determined as solutions to the author's spherical harmonic tide theory. The lengthening of the Chandler wobble period by the pole tide is also re-computed using the author's full theory. Additionally, using the spherical harmonic theory, tidal currents and their effects on rotation are determined for available numerical and altimetric tide height models. For all models, we find that the effects of tidal currents are at least as important as those of tide height for diurnal and semi-diurnal constituents.

Precessing rotating flows with additional shear: stability analysis.

Science.gov (United States)

Salhi, A; Cambon, C

2009-03-01

We consider unbounded precessing rotating flows in which vertical or horizontal shear is induced by the interaction between the solid-body rotation (with angular velocity Omega(0)) and the additional "precessing" Coriolis force (with angular velocity -epsilonOmega(0)), normal to it. A "weak" shear flow, with rate 2epsilon of the same order of the Poincaré "small" ratio epsilon , is needed for balancing the gyroscopic torque, so that the whole flow satisfies Euler's equations in the precessing frame (the so-called admissibility conditions). The base flow case with vertical shear (its cross-gradient direction is aligned with the main angular velocity) corresponds to Mahalov's [Phys. Fluids A 5, 891 (1993)] precessing infinite cylinder base flow (ignoring boundary conditions), while the base flow case with horizontal shear (its cross-gradient direction is normal to both main and precessing angular velocities) corresponds to the unbounded precessing rotating shear flow considered by Kerswell [Geophys. Astrophys. Fluid Dyn. 72, 107 (1993)]. We show that both these base flows satisfy the admissibility conditions and can support disturbances in terms of advected Fourier modes. Because the admissibility conditions cannot select one case with respect to the other, a more physical derivation is sought: Both flows are deduced from Poincaré's [Bull. Astron. 27, 321 (1910)] basic state of a precessing spheroidal container, in the limit of small epsilon . A Rapid distortion theory (RDT) type of stability analysis is then performed for the previously mentioned disturbances, for both base flows. The stability analysis of the Kerswell base flow, using Floquet's theory, is recovered, and its counterpart for the Mahalov base flow is presented. Typical growth rates are found to be the same for both flows at very small epsilon , but significant differences are obtained regarding growth rates and widths of instability bands, if larger epsilon values, up to 0.2, are considered. Finally

Rolling motion in moving droplets

Indian Academy of Sciences (India)

motions. The two limits of a thin sheet-like drop in sliding motion on a surface, and a spherical drop in roll, have been extensively .... rigid body rotation. The solid body rotation makes sense in the context of small Reynolds. (Re) number flows ...

Shoulder rotator isokinetic strength profile in young swimmers

Directory of Open Access Journals (Sweden)

Nuno Miguel Prazeres Batalha

2012-08-01

Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2012v14n5p545  Considering that some studies suggest that shoulder rotators muscle imbal­ances are related to joint pain and injury, and that there are no normative data for young swimmers, the aim of this study was: i to describe the muscle balance, fatigue and isokinetic strength profile of the shoulder rotators in young swimmers; ii to compare the results between swimmers and a group of young non-practitioners; iii to contribute to the acquisition of normative data of unilateral ratios of shoulder rotators. We evaluated the shoulder rotators concentric strength and unilateral ratios (ratio between torque of external and internal rotators of 60 swimmers (age: 14.55 ± 0.5 years old; body mass: 61.16 ± 7.08 kg and 60 non-practitioners (age: 14.62 ± 0.49 years old; body mass: 60.22 ± 10.01 kg. The evaluation was performed in the sitting position (90° abduction and elbow flexion at 60º.s-1 and 180º.s-1 angular speeds using an isokinetic dynamometer (Biodex System 3. The results of the fatigue ratios revealed no differences between the groups. Swimmers showed unilateral ratios of 73.39 ± 17.26% in the dominant limb (DL and 77.89 ± 15,23% in the non-dominant limb (NDL for assessments at 60º.s-1. At 180º.s-1, ratios were 74.77± 13.99% for DL and 70.11 ± 14.57% for NDL. Swimmers presented greater muscle imbalance, and differed from non-practitioners in the ability to produce power with the internal rotators, which was significantly higher in the former group.

Linearized stationary incompressible flow around rotating and translating bodies: Asymptotic profile of the velocity gradient and decay estimate of the second derivatives of the velocity

Czech Academy of Sciences Publication Activity Database

Deuring, P.; Kračmar, S.; Nečasová, Šárka

2012-01-01

Roč. 252, č. 1 (2012), s. 459-476 ISSN 0022-0396 R&D Projects: GA AV ČR IAA100190804; GA ČR(CZ) GAP201/11/1304 Institutional research plan: CEZ:AV0Z10190503 Keywords : viscous incompressible flow * rotating body * rundamental solution * decay * asymptotic profile * Navier-Stokes system Subject RIV: BA - General Mathematics Impact factor: 1.480, year: 2012 http://www.sciencedirect.com/science/article/pii/S0022039611003573

Development of three dimensional solid modeler

International Nuclear Information System (INIS)

Zahoor, R.M.A.

1999-01-01

The work presented in this thesis is aimed at developing a three dimensional solid modeler employing computer graphics techniques using C-Language. Primitives have been generated, by combination of plane surfaces, for various basic geometrical shapes including cylinder, cube and cone. Back face removal technique for hidden surface removal has also been incorporated. Various transformation techniques such as scaling, translation, and rotation have been included for the object animation. Three dimensional solid modeler has been created by the union of two primitives to demonstrate the capabilities of the developed program. (author)

Development of the plastic solid-dye cell for tunable solid-state dye lasers and study on its optical properties

Energy Technology Data Exchange (ETDEWEB)

Ko, Do Kyeong; Lee, Jong Min; Cha, Byung Heon; Jung, E. C.; Kim, Hyun Su; Lim, Gwon

2001-01-01

we have fabricated solid-state dyes with PMMA and sol-gel materials. We developed single longitudianl mode solid-state dye laser with the linewidth of less than 500MHz. We have constructed a self-seeded laser and observed the increase of the output power because of self-seeding effect. We investigated the operating characteristics of the dualwave laser oscillator and DFDL with solid-state dyes. And we have constructed the 3-color solid-state dye laser oscillator and amplifier system and observed 3-color operation. We also improved the laser oscliiator with disk-type solid-state dye cell which can be translated and rotated with the help of the two stepping motors. With the help of computer control, we could constantly changed the illuminated area of the dye cell and, therefore, were able to achieve long time operation and to use almost the entire region of the solid-state dye cell.

TIDALLY DRIVEN DYNAMOS IN A ROTATING SPHERE

International Nuclear Information System (INIS)

Cébron, D.; Hollerbach, R.

2014-01-01

Large-scale planetary or stellar magnetic fields generated by a dynamo effect are mostly attributed to flows forced by buoyancy forces in electrically conducting fluid layers. However, these large-scale fields may also be controlled by tides, as previously suggested for the star τ-boo, Mars, or the early Moon. By simulating a small local patch of a rotating fluid, Barker and Lithwick have recently shown that tides can drive small-scale dynamos by exciting a hydrodynamic instability, the so-called elliptical (or tidal) instability. By performing global magnetohydrodynamic simulations of a rotating spherical fluid body, we investigate if this instability can also drive the observed large-scale magnetic fields. We are thus interested in the dynamo threshold and the generated magnetic field in order to test if such a mechanism is relevant for planets and stars. Rather than solving the problem in a geometry deformed by tides, we consider a spherical fluid body and add a body force to mimic the tidal deformation in the bulk of the fluid. This allows us to use an efficient spectral code to solve the magnetohydrodynamic problem. We first compare the hydrodynamic results with theoretical asymptotic results and numerical results obtained in a truly deformed ellipsoid, which confirms the presence of elliptical instability. We then perform magnetohydrodynamic simulations and investigate the dynamo capability of the flow. Kinematic and self-consistent dynamos are finally simulated, showing that the elliptical instability is capable of generating a dipole-dominated large-scale magnetic field in global simulations of a fluid rotating sphere

A Smoothed Finite Element-Based Elasticity Model for Soft Bodies

Directory of Open Access Journals (Sweden)

Juan Zhang

2017-01-01

Full Text Available One of the major challenges in mesh-based deformation simulation in computer graphics is to deal with mesh distortion. In this paper, we present a novel mesh-insensitive and softer method for simulating deformable solid bodies under the assumptions of linear elastic mechanics. A face-based strain smoothing method is adopted to alleviate mesh distortion instead of the traditional spatial adaptive smoothing method. Then, we propose a way to combine the strain smoothing method and the corotational method. With this approach, the amplitude and frequency of transient displacements are slightly affected by the distorted mesh. Realistic simulation results are generated under large rotation using a linear elasticity model without adding significant complexity or computational cost to the standard corotational FEM. Meanwhile, softening effect is a by-product of our method.

Optical Signature Analysis of Tumbling Rocket Bodies via Laboratory Measurements

Science.gov (United States)

Cowardin, H.; Lederer, S.; Liou, J.-C.

2012-01-01

The NASA Orbital Debris Program Office has acquired telescopic lightcurve data on massive intact objects, specifically spent rocket bodies, in order to ascertain tumble rates in support of the Active Debris Removal (ADR) task to help remediate the LEO environment. Rotation rates are needed to plan and develop proximity operations for potential future ADR operations. To better characterize and model optical data acquired from ground-based telescopes, the Optical Measurements Center (OMC) at NASA/JSC emulates illumination conditions in space using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. The OMC employs a 75-watt Xenon arc lamp as a solar simulator, an SBIG CCD camera with standard Johnson/Bessel filters, and a robotic arm to simulate an object's position and rotation. The light source is mounted on a rotary arm, allowing access any phase angle between 0 -- 360 degrees. The OMC does not attempt to replicate the rotation rates, but focuses on how an object is rotating as seen from multiple phase angles. The two targets studied are scaled (1:48), SL-8 Cosmos 3M second stages. The first target is painted in the standard government "gray" scheme and the second target is primary white, as used for commercial missions. This paper summarizes results of the two scaled rocket bodies, each rotated about two primary axes: (a) a spin-stabilized rotation and (b) an end-over-end rotation. The two rotation states are being investigated as a basis for possible spin states of rocket bodies, beginning with simple spin states about the two primary axes. The data will be used to create a database of potential spin states for future works to convolve with more complex spin states. The optical signatures will be presented for specific phase angles for each rocket body and shown in conjunction with acquired optical data from multiple telescope sources.

Comorbidities in rotator cuff disease: a case-control study.

Science.gov (United States)

Titchener, Andrew G; White, Jonathan J E; Hinchliffe, Sally R; Tambe, Amol A; Hubbard, Richard B; Clark, David I

2014-09-01

Rotator cuff disease is a common condition in the general population, but relatively little is known about its associated risk factors. We have undertaken a large case-control study using The Health Improvement Network database to assess and to quantify the relative contributions of some constitutional and environmental risk factors for rotator cuff disease in the community. Our data set included 5000 patients with rotator cuff disease who were individually matched with a single control by age, sex, and general practice (primary care practice). The median age at diagnosis was 55 years (interquartile range, 44-65 years). Multivariate analysis showed that the risk factors associated with rotator cuff disease were Achilles tendinitis (odds ratio [OR] = 1.78), trigger finger (OR = 1.99), lateral epicondylitis (OR = 1.71), and carpal tunnel syndrome (OR = 1.55). Oral corticosteroid therapy (OR = 2.03), oral antidiabetic use (OR = 1.66), insulin use (OR = 1.77), and "overweight" body mass index of 25.1 to 30 (OR = 1.15) were also significantly associated. Current or previous smoking history, body mass index of greater than 30, any alcohol intake, medial epicondylitis, de Quervain syndrome, cubital tunnel syndrome, and rheumatoid arthritis were not found to be associated with rotator cuff disease. We have identified a number of comorbidities and risk factors for rotator cuff disease. These include lateral epicondylitis, carpal tunnel syndrome, trigger finger, Achilles tendinitis, oral corticosteroid use, and diabetes mellitus. The findings should alert the clinician to comorbid pathologic processes and guide future research into the etiology of this condition. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

Evidence for quantization of mechanical rotation of magnetic nanoparticles.

Science.gov (United States)

Tejada, J; Zysler, R D; Molins, E; Chudnovsky, E M

2010-01-15

We report evidence of the quantization of the rotational motion of solid particles containing thousands of atoms. A system of CoFe2O4 nanoparticles confined inside polymeric cavities has been studied. The particles have been characterized by the x-ray diffraction, transmission electron microscopy, plasma mass spectroscopy, ferromagnetic resonance (FMR), and magnetization measurements. Magnetic and FMR data confirm the presence of particles that are free to rotate inside the cavities. Equidistant, temperature-independent jumps in the dependence of the microwave absorption on the magnetic field have been detected. This observation is in accordance with the expectation that orbital motion splits the low-field absorption line into multiple lines.

Semiclassical description of quantum rotator in terms of SU(2) coherent states

International Nuclear Information System (INIS)

Gitman, D M; Petrusevich, D A; Shelepin, A L

2013-01-01

We introduce coordinates of the rigid body (rotator) using mutual positions between body-fixed and space-fixed reference frames. Wave functions that depend on such coordinates can be treated as scalar functions of the group SU(2). Irreducible representations of the group SU(2) × SU(2) in the space of such functions describe their possible transformations under independent rotations of the both reference frames. We construct sets of the corresponding group SU(2) × SU(2) Perelomov coherent states (CS) with a fixed angular momentum j of the rotator as special orbits of the latter group. Minimization of different uncertainty relations is discussed. The classical limit corresponds to the limit j → ∞. Considering Hamiltonians of rotators with different characteristics, we study the time evolution of the constructed CS. In some cases, the CS time evolution is completely or partially reduced to their parameter time evolution. If these parameters are chosen as Euler angles, then they obey the Euler equations in the classical limit. Quantum corrections to the motion of the quantum rotator can be found from exact equations on the CS parameters. (paper)

Electro-mechanical coupling of rotating 3D beams

Directory of Open Access Journals (Sweden)

Stoykov S.

2016-01-01

Full Text Available A rotating thin-walled beam with piezoelectric element is analysed. The beam is considered to vibrate in space, hence the longitudinal, transverse and torsional deformations are taken into account. The bending deformations of the beam are modelled by assuming Timoshenko's theory. Torsion is included by considering that the cross section rotates as a rigid body but can deform in longitudinal direction due to warping. The warping function is computed preliminary by the finite element method. The equation of motion is derived by the principle of virtual work and discretized in space by the Ritz method. Electro-mechanical coupling is included in the model by considering the internal electrical energy and the electric charge output. The piezo-electric constitutive relations are used in reduced form. The beam is assumed to rotate about a fixed axis with constant speed. The equation of motion is derived in rotating coordinate system, but the influence of the rotation of the coordinate system is taken into account through the inertia forces. Results in time domain are presented for different speeds of rotation and frequencies of vibration. The influence of the speed of rotation and of the frequency of vibration on the electrical output is presented and analysed.

Characterization of actinide targets by low solid-angle alpha particle counting

CERN Document Server

Denecke, B; Pauwels, J; Robouch, P; Gilliam, D M; Hodge, P; Hutchinson, J M R; Nico, J S

1999-01-01

Actinide samples were characterized in an interlaboratory comparison between IRMM and NIST, including alpha-particle counting at defined low solid angle and counting in a 2 pi proportional gas counter. For this comparison, nine sup 2 sup 3 sup 3 UF sub 4 samples with high uniformity in the layer thickness were prepared at IRMM by deposition under vacuum. Polished silicon wafers were used as source substrates, and these were rotated during the deposition using a planetary rotation system. The estimated uncertainties for the defined low solid-angle methods were about 0.1% at both NIST and IRMM. The agreement of reported alpha-particle emission rates in the energy range 2.5-5.09 MeV was better than or equal to 0.02% for the defined solid-angle methods. When comparing total alpha-particle emission rates over the larger energy range 0-9 MeV (which includes all emissions from the daughter nuclides and the impurities), the agreement of the defined solid-angle methods was better than or equal to 0.05%. The 2 pi propo...

Whole-body MRI in comparison to skeletal scintigraphy for detection of skeletal metastases in patients with solid tumors

International Nuclear Information System (INIS)

Ghanem, N.; Altehoefer, C.; Winterer, J.; Schaefer, O.; Bley, T.A.; Langer, M.; Kelly, T.; Moser, E.

2004-01-01

The aim of this study was to compare the diagnostic efficacy of whole-body magnetic resonance imaging (WB-MRI) as a new and rapid examination technique with skeletal scintigraphy for detection of skeletal metastases from solid tumors. In 129 patients with solid malignant tumors, WB-MRI was performed for individual comparison with skeletal scintigraphy. Examinations were performed with the innovative AngioSURF trademark rolling table with integrated phased array surface coil and coronary TIRM sequences for different body regions. The results for WB-MRI and skeletal scintigraphy were concordant in 81% of the cases, whereby both procedures excluded skeletal metastases in 43%. WB-MRI and skeletal scintigraphy demonstrated skeletal metastases in 38% of the cases, whereby WB-MRI provided more comprehensive findings in 45%. In 12% of the cases, skeletal scintigraphy was superior to WB-MRI and in 19% the findings were discordant, whereby WB-MRI detected skeletal metastases in 15 cases which had not been found on skeletal scintigraphy. In nine cases, skeletal scintigraphy was positive when the WB-MRI was negative. In 60% of the cases, WB-MRI evidenced tumor-associated findings. WB-MRI represents a promising new staging technique for detection of skeletal metastases, which is more sensitive in many cases than skeletal scintigraphy in detecting and assessing the extent of skeletal metastases - and tumor-associated findings that are relevant for treatment strategy. (orig.) [de

Solids Accumulation Scouting Studies

Energy Technology Data Exchange (ETDEWEB)

Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

2012-09-26

The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

Measurement and Analysis of Rotational Energy of Nitrogen Molecular Beam by REMPI

International Nuclear Information System (INIS)

Mori, H.; Yamaguchi, H.; Kataoka, K.; Sugiyama, N.; Ide, K.; Niimi, T.

2008-01-01

Molecular beams are powerful tools for diagnoses of solid surfaces and gas-surface interaction tests. Unfortunately, there are very few reports about experimental analysis of internal energy distribution (e.g. rotational energy) of molecular beams of diatomic or polyatomic molecules, because measurement of internal energy distribution is very difficult. Spectroscopic measurement techniques based on resonantly enhanced multiphoton ionization (REMPI) is very powerful for measurement in highly rarefied gas flows. In this study, the REMPI method is applied to measurement of rotational energy distribution of nitrogen molecular beams. The REMPI spectrum of the molecular beam indicates the rotational temperature higher than the translational temperature of 7.2 K estimated by assuming isentropic flows. The O and P branches of the REMPI spectrum correspond to the rotational temperature of 30 K, but the S branch of the spectrum deviates from that at 30 K. It seems to be because the non-equilibrium rotational energy distribution of the molecular beam deviates from the Boltzmann distribution.

Spectroscopic studies of a high Mach-number rotating plasma flow

International Nuclear Information System (INIS)

Ando, Akira; Ashino, Masashi; Sagi, Yukiko; Inutake, Masaaki; Hattori, Kunihiko; Yoshinuma, Mikirou; Imasaki, Atsushi; Tobari, Hiroyuki; Yagai, Tsuyoshi

2001-01-01

Characteristics of an axially-magnetized rotating plasma are investigated by spectroscopy in the HITOP device of Tohoku University. A He plasma flows our axially and rotates azimuthally near the muzzle region of the MPD arcjet. Flow and rotational velocities and temperature of He ions and atoms are measured by Doppler shift and broadening of the HeII (γ=468.58 nm) and HeI (γ=587.56 nm) lines. Rotational velocity increases with the increase of axially-applied magnetic field strength and discharge current. As discharge current increases and mass flow rate decreases, the plasma flow velocity increases and T i increases. Ion acoustic Mach number of the plasma flow also increases, but tends to saturate at near 1. Radial profile of space potential is calculated from the obtained rotational velocity. The potential profile in the core region is parabolic corresponding to the observed rigid-body rotation of the core plasma. (author)

Spectroscopic studies of a high Mach-number rotating plasma flow

Energy Technology Data Exchange (ETDEWEB)

Ando, Akira; Ashino, Masashi; Sagi, Yukiko; Inutake, Masaaki; Hattori, Kunihiko; Yoshinuma, Mikirou; Imasaki, Atsushi; Tobari, Hiroyuki; Yagai, Tsuyoshi [Tohoku Univ., Dept. of Electrical Engineering, Sendai, Miyagi (Japan)

2001-07-01

Characteristics of an axially-magnetized rotating plasma are investigated by spectroscopy in the HITOP device of Tohoku University. A He plasma flows our axially and rotates azimuthally near the muzzle region of the MPD arcjet. Flow and rotational velocities and temperature of He ions and atoms are measured by Doppler shift and broadening of the HeII ({gamma}=468.58 nm) and HeI ({gamma}=587.56 nm) lines. Rotational velocity increases with the increase of axially-applied magnetic field strength and discharge current. As discharge current increases and mass flow rate decreases, the plasma flow velocity increases and T{sub i} increases. Ion acoustic Mach number of the plasma flow also increases, but tends to saturate at near 1. Radial profile of space potential is calculated from the obtained rotational velocity. The potential profile in the core region is parabolic corresponding to the observed rigid-body rotation of the core plasma. (author)

Axis of eye rotation changes with head-pitch orientation during head impulses about earth-vertical.

Science.gov (United States)

Migliaccio, Americo A; Schubert, Michael C; Clendaniel, Richard A; Carey, John P; Della Santina, Charles C; Minor, Lloyd B; Zee, David S

2006-06-01

The goal of this study was to assess how the axis of head rotation, Listing's law, and eye position influence the axis of eye rotation during brief, rapid head rotations. We specifically asked how the axis of eye rotation during the initial angular vestibuloocular reflex (VOR) changed when the pitch orientation of the head relative to Earth-vertical was varied, but the initial position of the eye in the orbit and the orientation of Listing's plane with respect to the head were fixed. We measured three-dimensional eye and head rotation axes in eight normal humans using the search coil technique during head-and-trunk (whole-body) and head-on-trunk (head-only) "impulses" about an Earth-vertical axis. The head was initially oriented at one of five pitch angles (30 degrees nose down, 15 degrees nose down, 0 degrees, 15 degrees nose up, 30 degrees nose up). The fixation target was always aligned with the nasooccipital axis. Whole-body impulses were passive, unpredictable, manual, rotations with peak-amplitude of approximately 20 degrees , peak-velocity of approximately 80 degrees /s, and peak-acceleration of approximately 1000 degrees /s2. Head-only impulses were also passive, unpredictable, manual, rotations with peak-amplitude of approximately 20 degrees , peak-velocity of approximately 150 degrees /s, and peak-acceleration of approximately 3000 degrees /s2. During whole-body impulses, the axis of eye rotation tilted in the same direction, and by an amount proportional (0.51 +/- 0.09), to the starting pitch head orientation (P rotation could be predicted from vectorial summation of the gains (eye velocity/head velocity) obtained for rotations about the pure yaw and roll head axes. Thus, even when the orientation of Listing's plane and eye position in the orbit are fixed, the axis of eye rotation during the VOR reflects a compromise between the requirements of Listing's law and a perfectly compensatory VOR.

INTERNAL STRUCTURE OF ASTEROIDS HAVING SURFACE SHEDDING DUE TO ROTATIONAL INSTABILITY

Energy Technology Data Exchange (ETDEWEB)

Hirabayashi, Masatoshi [Research Associate, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States); Sánchez, Diego Paul [Senior Research Associate, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States); Scheeres, Daniel J., E-mail: masatoshi.hirabayashi@colorado.edu [Richard Seebass Chair, Professor, Colorado Center for Astrodynamics Research, Aerospace Engineering Sciences, University of Colorado Boulder (United States)

2015-07-20

Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible structure of an asteroid interior that leads to surface shedding due to rapid rotation rates. A rubble pile asteroid is modeled as a spheroid composed of a surface shell and a concentric internal core, the entire assembly called the test body. The test body is assumed to be uniformly rotating around a constant rotation axis. We also assume that while the bulk density and the friction angle are constant, the cohesion of the surface shell is different from that of the internal core. First, developing an analytical model based on limit analysis, we provide the upper and lower bounds for the actual surface shedding condition. Second, we use a Soft-sphere Discrete Element Method (SSDEM) to study dynamical deformation of the test body due to a quasi-static spin-up. In this paper we show the consistency of both approaches. Additionally, the SSDEM simulations show that the initial failure always occurs locally and not globally. In addition, as the core becomes larger, the size of lofted components becomes smaller. These results imply that if there is a strong core in a progenitor body, surface shedding is the most likely failure mode.

INTERNAL STRUCTURE OF ASTEROIDS HAVING SURFACE SHEDDING DUE TO ROTATIONAL INSTABILITY

International Nuclear Information System (INIS)

Hirabayashi, Masatoshi; Sánchez, Diego Paul; Scheeres, Daniel J.

2015-01-01

Surface shedding of an asteroid is a failure mode where surface materials fly off due to strong centrifugal forces beyond the critical spin period, while the internal structure does not deform significantly. This paper proposes a possible structure of an asteroid interior that leads to surface shedding due to rapid rotation rates. A rubble pile asteroid is modeled as a spheroid composed of a surface shell and a concentric internal core, the entire assembly called the test body. The test body is assumed to be uniformly rotating around a constant rotation axis. We also assume that while the bulk density and the friction angle are constant, the cohesion of the surface shell is different from that of the internal core. First, developing an analytical model based on limit analysis, we provide the upper and lower bounds for the actual surface shedding condition. Second, we use a Soft-sphere Discrete Element Method (SSDEM) to study dynamical deformation of the test body due to a quasi-static spin-up. In this paper we show the consistency of both approaches. Additionally, the SSDEM simulations show that the initial failure always occurs locally and not globally. In addition, as the core becomes larger, the size of lofted components becomes smaller. These results imply that if there is a strong core in a progenitor body, surface shedding is the most likely failure mode

Einstein and solid-state physics

International Nuclear Information System (INIS)

Aut, I.

1982-01-01

A connection between the development of solid-state physics and the works and activity of Albert Einstein is traced. A tremendous Einstein contribution to solid state physics is marked. A strict establishment of particle-wave dualism; a conclusion about the applicability of the Plank radiation law not only to black body radiation; finding out particles indistinguishability - all three discoveries have a principle significance for solid state physics too

Gravitational Metric Tensor Exterior to Rotating Homogeneous ...

African Journals Online (AJOL)

The covariant and contravariant metric tensors exterior to a homogeneous spherical body rotating uniformly about a common φ axis with constant angular velocity ω is constructed. The constructed metric tensors in this gravitational field have seven non-zero distinct components.The Lagrangian for this gravitational field is ...

Broadband Rotational Spectroscopy

Science.gov (United States)

Pate, Brooks

2014-06-01

The past decade has seen several major technology advances in electronics operating at microwave frequencies making it possible to develop a new generation of spectrometers for molecular rotational spectroscopy. High-speed digital electronics, both arbitrary waveform generators and digitizers, continue on a Moore's Law-like development cycle that started around 1993 with device bandwidth doubling about every 36 months. These enabling technologies were the key to designing chirped-pulse Fourier transform microwave (CP-FTMW) spectrometers which offer significant sensitivity enhancements for broadband spectrum acquisition in molecular rotational spectroscopy. A special feature of the chirped-pulse spectrometer design is that it is easily implemented at low frequency (below 8 GHz) where Balle-Flygare type spectrometers with Fabry-Perot cavity designs become technologically challenging due to the mirror size requirements. The capabilities of CP-FTMW spectrometers for studies of molecular structure will be illustrated by the collaborative research effort we have been a part of to determine the structures of water clusters - a project which has identified clusters up to the pentadecamer. A second technology trend that impacts molecular rotational spectroscopy is the development of high power, solid state sources in the mm-wave/THz regions. Results from the field of mm-wave chirped-pulse Fourier transform spectroscopy will be described with an emphasis on new problems in chemical dynamics and analytical chemistry that these methods can tackle. The third (and potentially most important) technological trend is the reduction of microwave components to chip level using monolithic microwave integrated circuits (MMIC) - a technology driven by an enormous mass market in communications. Some recent advances in rotational spectrometer designs that incorporate low-cost components will be highlighted. The challenge to the high-resolution spectroscopy community - as posed by Frank De

Dynamic Effects of the Earth's Rotation Caused by the Annual and Semi-Annual Cyclic Mass Redistribution of the Planet

Directory of Open Access Journals (Sweden)

M. Yu. Barkin

2016-01-01

Full Text Available The paper deals with development of the theory of perturbed rotational motion of a celestial body with variable geometry of the masses. Its main task is to study the impact of annual and semi-annual variations of the Earth's mass geometry (a component of its inertia tensor, as well as a component of its relative angular momentum, on the movement of the Earth's poles and its axial rotation. The body is considered to be a free (isolated, and the problem formulation corresponds to the classical Liouville problem on rotation of a variable body. Euler conical movement of the axially symmetric body with an arbitrary constant half-angle  is assumed as the unperturbed motion. In the classical theory of the Earth's rotation this angle is usually assumed to be zero.In the last 20 years, accuracy to determine the Earth rotation parameters owing to using methods of space geodesy and method of Very Long Baseline Interferometry (VLBI has increased by about three orders of magnitude and has made about  i.e., in angle measure it is about 10 - 20 arc-microseconds. According to experts, the theory of the Earth's rotation with such precision is not created yet. The paper is focused just on the new dynamic studies of the Earth rotation at a higher level of accuracy than has been done in previous studies, using a new approach to the problem, based on the new forms of the equations of motion (in the Andoyer variables and the analytical methods of perturbation theory (small parameter method.The problem of perturbed rotational motion with variable geometry and variable mass relative angular momentum in the first approximation is solved in Andoyer variables and projections of the angular velocity of the planet rotation. The analytical solution allows us to run applications to study dynamic effects from above factors for various bodies in the solar system, including the Earth. The solution allowed us to obtain the following parameters of the fundamental effects in the

Canonical three-body angular basis

International Nuclear Information System (INIS)

Matveenko, A.V.

2001-01-01

Three-body problems are basic for the quantum mechanics of molecular, atomic, or nuclear systems. We demonstrate that their variational solution for rotational states can be greatly simplified. A special choice of coordinates (hyperspherical) and of the kinematics (body-fixed coordinate frame) allows one to choose basis functions in a form that makes the angular coupling trivial. (author)

Means and method for examining the human body by means of penetrating radiation

International Nuclear Information System (INIS)

1983-01-01

The invention relates to a tomography method in which data are obtained by directing a fan of X-ray beams to the human body. The fan can rotate around the body. Moreover, the sources may rotate about an axis perpendicular to the plane of irradiation. (Auth.)

Effect of radioactive radiation on catalytic properties of solid materials

Energy Technology Data Exchange (ETDEWEB)

Sokol' skii, D V; Kuzembaev, K K; Kel' man, I V [AN Kazakhskoj SSR, Alma-Ata. Inst. Organicheskogo Kataliza i Ehlektrokhimii

1977-05-01

General survey is made of the problem of radiation modification of the action of solid catalysts with respect to the various types of heterogeneous catalytic reactions. Consideration is given to the key mechanisms responsible for radiation damage in the interaction of high-energy radiation with a solid body. The effect of ionizing radiation on the adsorption capacity and catalytic activity of solid bodies is discussed.

Muonium atoms in liquid and solid neopentane

International Nuclear Information System (INIS)

Ng, B.W.; Stadlbauer, J.M.; Jean, Y.C.; Walker, D.C.

1982-10-01

Relatively long-lived muonium atoms have been observed in neopentane (2,2-dimethylpropane). The yields of all muon states are found to be essentially the same in liquid and solid neopentane and the same as those in water. These results have bearings on three matters of current interest in muonium chemistry: the origin of the 'background' spin relaxation; the formation mechanisms; and the change in yields at the liquid-solid phase transition. These data were obtained by the μSR technique (muon spin rotation) at the TRIUMF accelerator

Poisson and Porter-Thomas fluctuations in off-yrast rotational transitions

International Nuclear Information System (INIS)

Matsuo, M.; Doessing, T.; Herskind, B.; Frauendorf, S.

1993-01-01

Fluctuations associated with stretched E2 transitions from high-spin levels in nuclei around 168 Yb are investigated by a cranked shell model extended to include residual two-body interactions. In the cranked mean-field model without residual interactions, it is found that gamma-ray energies behave like random variables and the energy spectra show Poisson fluctuation. With two-body residual interactions included, the discrete transition pattern with unmixed rotational bands is still valid up to around 600 keV above yrast, in good agreement with experiments. At higher excitation energy, a gradual onset of rotational damping emerges. At 1.8 MeV above yrast, complete damping is observed with GOE-type fluctuations for both energy levels and transition strengths (Porter-Thomas fluctuations). (orig.)

Analysis of high-speed rotating flow inside gas centrifuge casing

Science.gov (United States)

Pradhan, Sahadev

2017-11-01

The generalized analytical model for the radial boundary layer inside the gas centrifuge casing in which the inner cylinder is rotating at a constant angular velocity Ωi while the outer one is stationary, is formulated for studying the secondary gas flow field due to wall thermal forcing, inflow/outflow of light gas along the boundaries, as well as due to the combination of the above two external forcing. The analytical model includes the sixth order differential equation for the radial boundary layer at the cylindrical curved surface in terms of master potential (χ) , which is derived from the equations of motion in an axisymmetric (r - z) plane. The linearization approximation is used, where the equations of motion are truncated at linear order in the velocity and pressure disturbances to the base flow, which is a solid-body rotation. Additional approximations in the analytical model include constant temperature in the base state (isothermal compressible Couette flow), high aspect ratio (length is large compared to the annular gap), high Reynolds number, but there is no limitation on the Mach number. The discrete eigenvalues and eigenfunctions of the linear operators (sixth-order in the radial direction for the generalized analytical equation) are obtained. The solutions for the secondary flow is determined in terms of these eigenvalues and eigenfunctions. These solutions are compared with direct simulation Monte Carlo (DSMC) simulations and found excellent agreement (with a difference of less than 15%) between the predictions of the analytical model and the DSMC simulations, provided the boundary conditions in the analytical model are accurately specified.

Occlusal plane rotation: aesthetic enhancement in mandibular micrognathia.

Science.gov (United States)

Rosen, H M

1993-06-01

Patients afflicted with extreme degrees of mandibular micrognathia typically have vertically deficient rami as well as sagittally deficient mandibular bodies. This results in deficient posterior facial height, an obtuse gonial angle, excessively steep occlusal and mandibular planes, and a compensatory increase in anterior facial height. The entire maxillomandibular complex is overrotated in a clockwise direction. Standard orthognathic surgical correction fails to address this rotational deformity. As a consequence, the achieved projection of the lower face is inadequate, posterior facial height is further reduced, and occlusal and mandibular planes remain steep. Eleven patients with severe mandibular micrognathia underwent a surgical correction involving occlusal plane rotation to its normal orientation relative to Frankfort horizontal. This was accomplished by Le Fort I osteotomy to shorten the anterior maxilla (creating open bites in seven patients and making preexisting open bites worse in four patients) and sagittal split ramus osteotomies to advance and rotate the mandibular body counterclockwise, thus closing the surgically produced open bite. Counterclockwise rotation of the mandible afforded significantly greater sagittal displacement at the B point (mean 17 mm) than at the first molar (mean 10 mm) and produced adequate degrees of projection of the lower face when accompanied by a modest sliding genioplasty (mean 6.9 mm). Total advancement at the pogonion was a mean of 25.2 mm. In addition, posterior facial height was preserved, and mandibular and occlusal planes were normalized to mean angles of 27 and 10 degrees, respectively. At follow-up, which ranged from 9 to 24 months with a mean of 14.1 months, the mean sagittal relapse at the B point was 1.9 mm. Although heretofore considered unstable and therefore not clinically accepted, maxillomandibular counterclockwise rotation to normalize the occlusal plane rotational deformity provides stable, aesthetically

Rotational Motion Control of a Spacecraft

DEFF Research Database (Denmark)

Wisniewski, Rafal; Kulczycki, P.

2001-01-01

The paper adopts the energy shaping method to control of rotational motion. A global representation of the rigid body motion is given in the canonical form by a quaternion and its conjugate momenta. A general method for motion control on a cotangent bundle to the 3-sphere is suggested. The design...... algorithm is validated for three-axis spacecraft attitude control...

Rotational motion control of a spacecraft

DEFF Research Database (Denmark)

Wisniewski, Rafal; Kulczycki, P.

2003-01-01

The paper adopts the energy shaping method to control of rotational motion. A global representation of the rigid body motion is given in the canonical form by a quaternion and its conjugate momenta. A general method for motion control on a cotangent bundle to the 3-sphere is suggested. The design...... algorithm is validated for three-axis spacecraft attitude control. Udgivelsesdato: APR...

Nonlinear elastic inclusions in isotropic solids

KAUST Repository

Yavari, A.; Goriely, A.

2013-01-01

We introduce a geometric framework to calculate the residual stress fields and deformations of nonlinear solids with inclusions and eigenstrains. Inclusions are regions in a body with different reference configurations from the body itself and can

Measuring service life and evaluating the quality of solid tires

Directory of Open Access Journals (Sweden)

Charoenyut Dechwayukul

2010-08-01

Full Text Available The objective of this research is to propose procedures for measuring service life and evaluating the quality of locallymade and used solid tires in Thailand. The solid tires were stressed and rotated until blowout on a drum-like test apparatuswhich is designed, constructed by the authors and equipped with laboratory instrumentation. Solid tires from five differentmanufacturers were selected for testing. We measured service life, length of time to tire failure, at three different loadingamplitudes and three different speeds on the testing drum. The service life of all specimens was studied and compared todetermine the possibility of using service life to evaluate the quality of a solid tire.

Scaling relations for plasma production and acceleration of rotating plasma flows

International Nuclear Information System (INIS)

Ikehata, Takashi; Tanabe, Toshio; Mase, Hiroshi; Sekine, Ryusuke; Hasegawa, Kazuyuki.

1989-01-01

Scaling relations are investigated theoretically and experimentally of the plasma production and acceleration in the rotating plasma gun which has been developed as a new means of plasma centrifuge. Two operational modes: the gas-discharge mode for gaseous elements and the vacuum-discharge mode for solid elements are studied. Relations of the plasma density and velocities to the discharge current and the magnetic field are derived. The agreement between experiment and theory is quite well. It is found that fully-ionized rotating plasmas produced in the gas-discharge mode is most advantageous to realize efficient plasma centrifuge. (author)

Rotational Seismology: AGU Session, Working Group, and Website

Science.gov (United States)

Lee, William H.K.; Igel, Heiner; Todorovska, Maria I.; Evans, John R.

2007-01-01

Introduction Although effects of rotational motions due to earthquakes have long been observed (e. g., Mallet, 1862), nevertheless Richter (1958, p. 213) stated that: 'Perfectly general motion would also involve rotations about three perpendicular axes, and three more instruments for these. Theory indicates, and observation confirms, that such rotations are negligible.' However, Richter provided no references for this claim. Seismology is based primarily on the observation and modeling of three-component translational ground motions. Nevertheless, theoretical seismologists (e.g., Aki and Richards, 1980, 2002) have argued for decades that the rotational part of ground motions should also be recorded. It is well known that standard seismometers are quite sensitive to rotations and therefore subject to rotation-induced errors. The paucity of observations of rotational motions is mainly the result of a lack, until recently, of affordable rotational sensors of sufficient resolution. Nevertheless, in the past decade, a number of authors have reported direct observations of rotational motions and rotations inferred from rigid-body rotations in short baseline accelerometer arrays, creating a burgeoning library of rotational data. For example, ring laser gyros in Germany and New Zealand have led to the first significant and consistent observations of rotational motions from distant earthquakes (Igel et al., 2005, 2007). A monograph on Earthquake Source Asymmetry, Structural Media and Rotation Effects was published recently as well by Teisseyre et al. (2006). Measurement of rotational motions has implications for: (1) recovering the complete ground-displacement history from seismometer recordings; (2) further constraining earthquake rupture properties; (3) extracting information about subsurface properties; and (4) providing additional ground motion information to earthquake engineers for seismic design. A special session on Rotational Motions in Seismology was convened by H

Rotational Spectra of Adrenaline and Noradrenaline

Science.gov (United States)

Cortijo, V.; López, J. C.; Alonso, J. L.

2009-06-01

The emergence of Laser Ablation Molecular Beam Fourier Transform Microwave (LA-MB-FTMW) spectroscopy has rendered accessible the gas-phase study of solid biomolecules with high melting points. Among the biomolecules to benefit from this technique, neurotransmitters have received special attention due to the lack of experimental information and their biological relevance. As a continuation of the we present the study of adrenaline and noradrenaline. The comparison between the experimental rotational and ^{14}N nuclear quadrupole coupling constants and those calculated ab initio provide a definitive test for molecular structures and confirm unambiguously the identification of four conformers of adrenaline and three conformers of noradrenaline. Their relative population in the jet has been evaluated by relative intensity measurements of selected rotational transitions. The most abundant conformer in both neurotransmitters present an extended AG configuration with a O-H\\cdotsN hydrogen bond in the side chain. J.L. Alonso, M.E. Sanz, J.C. López and V. Cortijo, J. Am. Chem. Soc. (in press), 2009

The two-body problem of a pseudo-rigid body and a rigid sphere

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall; Vereshchagin, M.; Gózdziewski, K.

2012-01-01

n this paper we consider the two-body problem of a spherical pseudo-rigid body and a rigid sphere. Due to the rotational and "re-labelling" symmetries, the system is shown to possess conservation of angular momentum and circulation. We follow a reduction procedure similar to that undertaken...... in the study of the two-body problem of a rigid body and a sphere so that the computed reduced non-canonical Hamiltonian takes a similar form. We then consider relative equilibria and show that the notions of locally central and planar equilibria coincide. Finally, we show that Riemann's theorem on pseudo......-rigid bodies has an extension to this system for planar relative equilibria....

Rotational structure of the five lowest frequency fundamental vibrational states of dimethylsulfoxide

Science.gov (United States)

Cuisset, Arnaud; Drumel, Marie-Aline Martin; Hindle, Francis; Mouret, Gaël; Sadovskií, Dmitrií A.

2013-10-01

We report on the successful extended analysis of the high-frequency (200-700 GHz) part of the gas phase (sub)mm-wave spectra of dimethylsulfoxide (DMSO). The spectrum was recorded at 100 kHz resolution using a solid state subTHz spectrometer. The five lowest energy fundamental vibrational states of DMSO with frequencies below 400 cm-1 were observed as sidebands along with the main 0←0 band. Neglecting the internal rotation of methyls, our rotational Hamiltonian reproduced the spectrum to the subMHz accuracy. We have found that the asymmetric bending state ν23 is the only low frequency fundamental vibrational state with the "anomalous" rotational structure uncovered in Cuisset et al. [1]. dmsomw 2013-09-04 15:03

Neutron cross sections of cryogenic materials: a synthetic kernel for molecular solids

International Nuclear Information System (INIS)

Granada, J.R.; Gillette, V.H.; Petriw, S.; Cantargi, F.; Pepe, M.E.; Sbaffoni, M.M.

2004-01-01

A new synthetic scattering function aimed at the description of the interaction of thermal neutrons with molecular solids has been developed. At low incident neutron energies, both lattice modes and molecular rotations are specifically accounted for, through an expansion of the scattering law in few phonon terms. Simple representations of the molecular dynamical modes are used, in order to produce a fairly accurate description of neutron scattering kernels and cross sections with a minimum set of input data. As the neutron energies become much larger than that corresponding to the characteristic Debye temperature and to the rotational energies of the molecular solid, the 'phonon formulation' transforms into the traditional description for molecular gases. (orig.)

Seismic rotation waves: basic elements of theory and recording

Directory of Open Access Journals (Sweden)

P. Palangio

2003-06-01

Full Text Available Returning to the old problem of observed rotation effects, we present the recording system and basic elements of the theory related to the rotation fi eld and its association with seismic waves. There can be many different causes leading to observed/recorded rotation effects; we can group them as follows: generation of micro-displacement motion due to asymmetry of source processes and/or due to interaction between seismic body/surface waves and medium structure; interaction between incident seismic waves and objects situated on the ground surface. New recording techniques and advanced theory of deformation in media with defects and internal (e.g., granular structure make it possible to focus our attention on the fi rst group, related to microdisplacement motion recording, which includes both rotation and twist motions. Surface rotations and twists caused directly by the action of emerging seismic waves on some objects situated on the ground surface are considered here only in the historical aspects of the problem. We present some examples of experimental results related to recording of rotation and twist components at the Ojcow Observatory, Poland, and L'Aquila Observatory, Italy, and we discuss some prospects for further research.

Measurement of scattering cross sections of liquid and solid hydrogen, deuterium and deuterium hydride for thermal neutrons

International Nuclear Information System (INIS)

Seiffert, W.D.

1984-01-01

The scattering cross sections for liquid and solid normal hydrogen, para-hydrogen, deuterium and deuterium hydride were measured for thermal neutrons at various temperatures. Solid samples of para-hydrogen exhibit distinct Bragg scattering. Liquid samples of deuterium and para-hydrogen also exhibit distinct coherence phenomena, which is indicative of strong local ordering of the molecules. In para-hydrogen and deuterium hydride, the threshold for scattering with excitation of rotations is distinctly visible. The positions of the thresholds show that the molecules in liquid hydrogen are not unhindered in their movement. After the beginning of the rotational excitation the scattering cross sections of liquid and solid para-hydrogen have different shapes which is to be explained by the differences in the dynamics of the liquid and the solid specimen. 22 references

Three-dimensional optoacoustic tomography using a conventional ultrasound linear detector array: whole-body tomographic system for small animals.

Science.gov (United States)

Gateau, Jerome; Caballero, Miguel Angel Araque; Dima, Alexander; Ntziachristos, Vasilis

2013-01-01

Optoacoustic imaging relies on the detection of ultrasonic waves induced by laser pulse excitations to map optical absorption in biological tissue. A tomographic geometry employing a conventional ultrasound linear detector array for volumetric optoacoustic imaging is reported. The geometry is based on a translate-rotate scanning motion of the detector array, and capitalizes on the geometrical characteristics of the transducer assembly to provide a large solid angular detection aperture. A system for three-dimensional whole-body optoacoustic tomography of small animals is implemented. The detection geometry was tested using a 128-element linear array (5.0∕7.0 MHz, Acuson L7, Siemens), moved by steps with a rotation∕translation stage assembly. Translation and rotation range of 13.5 mm and 180°, respectively, were implemented. Optoacoustic emissions were induced in tissue-mimicking phantoms and ex vivo mice using a pulsed laser operating in the near-IR spectral range at 760 nm. Volumetric images were formed using a filtered backprojection algorithm. The resolution of the optoacoustic tomography system was measured to be better than 130 μm in-plane and 330 μm in elevation (full width half maximum), and to be homogenous along a 15 mm diameter cross section due to the translate-rotate scanning geometry. Whole-body volumetric optoacoustic images of mice were performed ex vivo, and imaged organs and blood vessels through the intact abdominal and head regions were correlated to the mouse anatomy. Overall, the feasibility of three-dimensional and high-resolution whole-body optoacoustic imaging of small animal using a conventional linear array was demonstrated. Furthermore, the scanning geometry may be used for other linear arrays and is therefore expected to be of great interest for optoacoustic tomography at macroscopic and mesoscopic scale. Specifically, conventional detector arrays with higher central frequencies may be investigated.

Thermal convection in a co-rotating cylindrical annulus

Science.gov (United States)

Kang, Changwoo; Meyer, Antoine; Mutabazi, Innocent

2017-11-01

We investigate thermal convection in a fluid of thermal expansion coefficient α, kinematic viscosity ν, thermal diffusivity κ in a cylindrical annulus of inner radius a and outer radius bwith a solid body rotation of angular frequency Ω and an inward heating with a temperature difference ΔT. The control parameters are η = a/b, Pr = ν / κ and the Rayleigh number Ra = αΔ T gd3 / νκ where the centrifugal gravity gc =Ω2 (a +b)/2. We adopt the generalized Boussinesq approximation. Linear stability analysis shows that for infinite annulus, the threshold Rac decreases with η and tends to the value Rac = 1708 when η -> 1 and that critical modes are columnar vortices. Direct numerical simulations using periodic boundary conditions in the axial direction, show that the columnar vortices appear via a supercritical bifurcation. Higher modes of columnar vortices have been determined using the frequency spectra and the Nusselt number for Pr =1 and η = 0.5 : drifting vortices, vacillation modes and chaotic modes have been identified from Ra =1700 to Ra =107 The contribution of the centrifugal buoyancy to the variation of the kinetic energy in the flow is analysed. This work was supported by the project BIOENGINE (CPER-FEDER, Normandie) and CNES.

Synovial Chondromatosis of the Subacromial Bursa Causing a Bursal-Sided Rotator Cuff Tear

Directory of Open Access Journals (Sweden)

Julie A. Neumann

2015-01-01

Full Text Available Synovial chondromatosis is an uncommon condition, and involvement of the shoulder is even more rare. We report on a 39-year-old female who presented with symptoms, radiographic features, and intraoperative findings consistent with multiple subacromial loose bodies resulting in a partial-thickness, bursal-sided rotator cuff tear of the supraspinatus muscle. She was treated with an arthroscopic removal of loose bodies, complete excision of the subacromial/subdeltoid bursa, acromioplasty, and rotator cuff repair. To our knowledge, this is the first report of arthroscopic treatment for a bursal-sided, partial-thickness rotator cuff tear treated with greater than two-year clinical and radiographic follow-up. We utilized shoulder scores, preoperative and postoperative range of motion, and imaging to assess the results of treatment and surveillance for recurrence in our patient after two-year follow-up.

Rotator cuff tendon connections with the rotator cable.

Science.gov (United States)

Rahu, Madis; Kolts, Ivo; Põldoja, Elle; Kask, Kristo

2017-07-01

The literature currently contains no descriptions of the rotator cuff tendons, which also describes in relation to the presence and characteristics of the rotator cable (anatomically known as the ligamentum semicirculare humeri). The aim of the current study was to elucidate the detailed anatomy of the rotator cuff tendons in association with the rotator cable. Anatomic dissection was performed on 21 fresh-frozen shoulder specimens with an average age of 68 years. The rotator cuff tendons were dissected from each other and from the glenohumeral joint capsule, and the superior glenohumeral, coracohumeral, coracoglenoidal and semicircular (rotator cable) ligaments were dissected. Dissection was performed layer by layer and from the bursal side to the joint. All ligaments and tendons were dissected in fine detail. The rotator cable was found in all specimens. It was tightly connected to the supraspinatus (SSP) tendon, which was partly covered by the infraspinatus (ISP) tendon. The posterior insertion area of the rotator cable was located in the region between the middle and inferior facets of the greater tubercle of the humerus insertion areas for the teres minor (TM), and ISP tendons were also present and fibres from the SSP extended through the rotator cable to those areas. The connection between the rotator cable and rotator cuff tendons is tight and confirms the suspension bridge theory for rotator cuff tears in most areas between the SSP tendons and rotator cable. In its posterior insertion area, the rotator cable is a connecting structure between the TM, ISP and SSP tendons. These findings might explain why some patients with relatively large rotator cuff tears can maintain seamless shoulder function.

Influence of Geometry and Velocity of Rotating Solids on Hydrodynamics of a Confined Volume

Directory of Open Access Journals (Sweden)

Ignacio Carvajal-Mariscal

2017-01-01

Full Text Available Three cylinder-based geometries were evaluated at five different rotating speeds (ω = 20.94, 62.83, 94.25, 125.66, and 157.08 rad·s−1 to obtain the fluid flow pattern in nonsteady conditions. Two of the models were modified at the lower region, also known as tip section, by means of inverted and right truncated cone geometries, respectively. The experimental technique used a visualization cell and a Particle Imaging Velocimetry installation to obtain the vector field at the central plane of the volume. The Line Integral Convolution Method was used to obtain the fluid motion at the plane. In addition, the scalar kinetic energy and the time series were calculated to perform the normal probability plot. This procedure was used to determine the nonlinear fluid flow pattern. It was also used to identify two different flow regimens in physical and numerical results. As the rotation speed increased, the turbulent regions were placed together and moved. The process makes experimental observation difficult. The biphasic and turbulence constitutive equations were solved with the Computational Fluid Dynamics technique. Numerical results were compared with physical experiments for validation. The model with the inverted truncated cone tip presented better stability in the fluid flow pattern along the rotation speed range.

Kinetic-contact-driven gigantic energy transfer in a two-dimensional Lennard-Jones fluid confined to a rotating pore

Science.gov (United States)

Karbowniczek, Paweł; Chrzanowska, Agnieszka

2017-11-01

A two-dimensional Lennard-Jones system in a circular and rotating container has been studied by means of molecular dynamics technique. A nonequilibrium transition to the rotating stage has been detected in a delayed time since an instant switching of the frame rotation. This transition is attributed to the increase of the density at the wall because of the centrifugal force. At the same time the phase transition occurs, the inner system changes its configuration of the solid-state type into the liquid type. Impact of angular frequency and molecular roughness on the transport properties of the nonrotating and rotating systems is analyzed.

Isotopic and spin-nuclear effects in solid hydrogens (Review Article)

Science.gov (United States)

Freiman, Yuri A.; Crespo, Yanier

2017-12-01

The multiple isotopic family of hydrogens (H2, HD, D2, HT, DT, T2) due to large differences in the de Boer quantum parameter and inertia moments displays a diversity of pronounced quantum isotopic solid-state effects. The homonuclear members of this family (H2, D2, T2) due to the permutation symmetry are subjects of the constraints of quantum mechanics which link the possible rotational states of these molecules to their total nuclear spin giving rise to the existence of two spin-nuclear modifications, ortho- and parahydrogens, possessing substantially different properties. Consequently, hydrogen solids present an unique opportunity for studying both isotope and spin-nuclear effects. The rotational spectra of heteronuclear hydrogens (HD, HT, DT) are free from limitations imposed by the permutation symmetry. As a result, the ground state of these species in solid state is virtually degenerate. The most dramatic consequence of this fact is an effect similar to the Pomeranchuk effect in 3He which in the case of the solid heteronuclear hydrogens manifests itself as the reentrant broken symmetry phase transitions. In this review article we discuss thermodynamic and kinetic effects pertaining to different isotopic and spin-nuclear species, as well as problems that still remain to be solved.

A numerical study of the influence of feeding polycrystalline silicon granules on melt temperature in the continuous Czochralski process

Science.gov (United States)

Ono, Naoki; Kida, Michio; Arai, Yoshiaki; Sahira, Kensho

1993-09-01

Temperature change was simulated using a solid body rotating melt model when solid polycrystalline silicon granules were supplied to a melt in a double-crucible method. Only heat conduction was considered in the analysis. The influence of the crucible rotation rates and of the initial temperature of the supplied silicon was investigated systematically and quantitatively. The influence of the crucible rotation rate was stronger than expected, which suggests that the crucible rotation rate cannot be lowered too much because of the possibility of the melt solidifying between the inner and outer crucibles.

Method and device of decontaminating radioactive solid wastes

International Nuclear Information System (INIS)

Hasegawa, Hiroshi; Tamada, Masami.

1983-01-01

Purpose: To surely enable grinding for the inner surface of hollow radioactive solid wastes such as pipeways or valves, as well as enable to decontaminate these solid wastes to such a level as being capable of processing in the same manner for the ordinary wastes. Method: A grinding piece abutting resiliently against the inner surface of a hollow radioactive solid wastes to be contaminated is attached at the top end of a flexible shaft, and the inner surface of the radioactive solid wastes is ground while rotating and slightly reciprocating, as well as axially moving the flexible shaft. Consequently, since the grinding piece is always abutted against the inner surface of the radioactive solid wastes just following after the profile of the inner surface, and the flexible shaft is resiliently flexed corresponding to the profile of the inner surface of the radioactive solid wastes, even an inner surface of radioactive solid wastes with a complicated configuration can surely be ground entirely. This surely enables to remove radioactive claddings and contaminated layers deposited on the surface. (Yoshihara, H.)

Anisotropic intermolecular interaction and rotational ordering in hydrogen-containing solids. Progress report No. 12

Energy Technology Data Exchange (ETDEWEB)

1976-01-01

Progress is reviewed in these areas: nuclear spin-lattice relaxation in ortho-para mixtures of solid deuterium below T/sub lambda/; pulsed NMR experiments of matrix isolated HCl; stimulated Raman scattering in solid hydrogen and nitrogen; and infrared line broadening of matrix isolated molecules. (GHT)

Anisotropic intermolecular interaction and rotational ordering in hydrogen-containing solids. Progress report No. 12

International Nuclear Information System (INIS)

1976-01-01

Progress is reviewed in these areas: nuclear spin-lattice relaxation in ortho-para mixtures of solid deuterium below T/sub lambda/; pulsed NMR experiments of matrix isolated HCl; stimulated Raman scattering in solid hydrogen and nitrogen; and infrared line broadening of matrix isolated molecules

GALAXY ROTATION AND RAPID SUPERMASSIVE BINARY COALESCENCE

Energy Technology Data Exchange (ETDEWEB)

Holley-Bockelmann, Kelly [Vanderbilt University, Nashville, TN (United States); Khan, Fazeel Mahmood, E-mail: k.holley@vanderbilt.edu [Institute of Space Technology (IST), Islamabad (Pakistan)

2015-09-10

Galaxy mergers usher the supermassive black hole (SMBH) in each galaxy to the center of the potential, where they form an SMBH binary. The binary orbit shrinks by ejecting stars via three-body scattering, but ample work has shown that in spherical galaxy models, the binary separation stalls after ejecting all the stars in its loss cone—this is the well-known final parsec problem. However, it has been shown that SMBH binaries in non-spherical galactic nuclei harden at a nearly constant rate until reaching the gravitational wave regime. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in both corotating and counterrotating flattened galaxy models. For N > 500 K, we find that the evolution of the SMBH binary is convergent and is independent of the particle number. Rotation in general increases the hardening rate of SMBH binaries even more effectively than galaxy geometry alone. SMBH binary hardening rates are similar for co- and counterrotating galaxies. In the corotating case, the center of mass of the SMBH binary settles into an orbit that is in corotation resonance with the background rotating model, and the coalescence time is roughly a few 100 Myr faster than a non-rotating flattened model. We find that counterrotation drives SMBHs to coalesce on a nearly radial orbit promptly after forming a hard binary. We discuss the implications for gravitational wave astronomy, hypervelocity star production, and the effect on the structure of the host galaxy.

GALAXY ROTATION AND RAPID SUPERMASSIVE BINARY COALESCENCE

International Nuclear Information System (INIS)

Holley-Bockelmann, Kelly; Khan, Fazeel Mahmood

2015-01-01

Galaxy mergers usher the supermassive black hole (SMBH) in each galaxy to the center of the potential, where they form an SMBH binary. The binary orbit shrinks by ejecting stars via three-body scattering, but ample work has shown that in spherical galaxy models, the binary separation stalls after ejecting all the stars in its loss cone—this is the well-known final parsec problem. However, it has been shown that SMBH binaries in non-spherical galactic nuclei harden at a nearly constant rate until reaching the gravitational wave regime. Here we use a suite of direct N-body simulations to follow SMBH binary evolution in both corotating and counterrotating flattened galaxy models. For N > 500 K, we find that the evolution of the SMBH binary is convergent and is independent of the particle number. Rotation in general increases the hardening rate of SMBH binaries even more effectively than galaxy geometry alone. SMBH binary hardening rates are similar for co- and counterrotating galaxies. In the corotating case, the center of mass of the SMBH binary settles into an orbit that is in corotation resonance with the background rotating model, and the coalescence time is roughly a few 100 Myr faster than a non-rotating flattened model. We find that counterrotation drives SMBHs to coalesce on a nearly radial orbit promptly after forming a hard binary. We discuss the implications for gravitational wave astronomy, hypervelocity star production, and the effect on the structure of the host galaxy

Whole-body magnetic resonance imaging for detection of skeletal metastases in children and young people with primary solid tumors - systematic review

International Nuclear Information System (INIS)

Smets, A.M.; Deurloo, E.E.; Slager, T.J.E.; Stoker, J.; Bipat, S.

2018-01-01

Many solid neoplasms have a propensity for osteomedullary metastases of which detection is important for staging and subsequent treatment. Whole-body magnetic resonance imaging (WB-MRI) has been shown to accurately detect osteomedullary metastases in adults, but these findings cannot be unconditionally extrapolated to staging of children with malignant solid tumors. To conduct a literature review on the sensitivity of WB-MRI for detecting skeletal metastases in children with solid tumors. Searches in MEDLINE and EMBASE databases up to 15 May 2017 were performed to identify studies on the diagnostic value of WB-MRI. Inclusion criteria were children and adolescents (age <21 years) with a primary solid tumor who were evaluated for skeletal metastases by WB-MRI and compared to any type of reference standard. The number of included patients had to be at least five and data on true positives, true negatives, false-positives and false-negatives had to be extractable. Five studies including 132 patients (96 patients with solid tumors) were eligible. Patient groups and used reference tests were heterogeneous, producing unclear or high risk of bias. Sensitivity of WB-MRI ranged between 82% and 100%. The positive predictive value of WB-MRI was variable among the studies and influenced by the used reference standard. Although WB-MRI may seem a promising radiation-free technique for the detection of skeletal metastases in children with solid tumors, published studies are small and too heterogeneous to provide conclusive evidence that WB-MRI can be an alternative to currently used imaging techniques. (orig.)

Whole-body magnetic resonance imaging for detection of skeletal metastases in children and young people with primary solid tumors - systematic review

Energy Technology Data Exchange (ETDEWEB)

Smets, A.M.; Deurloo, E.E.; Slager, T.J.E.; Stoker, J.; Bipat, S. [Academic Medical Center (AMC), Department of Radiology and Nuclear Medicine, Amsterdam (Netherlands)

2018-02-15

Many solid neoplasms have a propensity for osteomedullary metastases of which detection is important for staging and subsequent treatment. Whole-body magnetic resonance imaging (WB-MRI) has been shown to accurately detect osteomedullary metastases in adults, but these findings cannot be unconditionally extrapolated to staging of children with malignant solid tumors. To conduct a literature review on the sensitivity of WB-MRI for detecting skeletal metastases in children with solid tumors. Searches in MEDLINE and EMBASE databases up to 15 May 2017 were performed to identify studies on the diagnostic value of WB-MRI. Inclusion criteria were children and adolescents (age <21 years) with a primary solid tumor who were evaluated for skeletal metastases by WB-MRI and compared to any type of reference standard. The number of included patients had to be at least five and data on true positives, true negatives, false-positives and false-negatives had to be extractable. Five studies including 132 patients (96 patients with solid tumors) were eligible. Patient groups and used reference tests were heterogeneous, producing unclear or high risk of bias. Sensitivity of WB-MRI ranged between 82% and 100%. The positive predictive value of WB-MRI was variable among the studies and influenced by the used reference standard. Although WB-MRI may seem a promising radiation-free technique for the detection of skeletal metastases in children with solid tumors, published studies are small and too heterogeneous to provide conclusive evidence that WB-MRI can be an alternative to currently used imaging techniques. (orig.)

Meteoroid rotation and fireball flickering: a case study of the Innisfree fireball

Science.gov (United States)

Beech, Martin

2001-09-01

Some 5 per cent of bright meteors show rapid, quasi-periodic brightness variations. It is argued that this effect, observationally known as flickering, is a manifestation of the rotational modulation of surface mass loss through ablation of a non-spherical meteoroid. We develop a set of time-dependent, single-body ablation equations that include the effect of cross-section area modulation. We present a discussion of the effects that the rotation of a non-spherical meteoroid has on the resultant meteor light curve, and we look in depth at the data related to the fireball associated with the fall of the Innisfree meteorite. We find that the parent object to the Innisfree meteorite was spinning at a rotation frequency of 2.5Hz when it encountered the Earth's upper atmosphere. We also find that the Innisfree parent body had an initial mass of about 20kg and that the ratio of its semiminor and semimajor axes was about 0.5.

Rotating anode x-ray tube

International Nuclear Information System (INIS)

Hueschen, R.E.; Jens, R.A.

1980-01-01

A solid low thermal conductivity columbium metal stem supports heavy refractory metal x-ray target and adjoins high thermal conductivity rotor hub fastened to rotor with low thermally conductive bearing hub fastened to a shaft journaled for rotation in bearings. The rotor is coated to enhance heat dissipation and the arrangement promotes thermal isolation of the bearings from the hot rotor hub and hot target. The hub is of Mo or Mo based alloy, and hub of Ni based alloy. Specific compositions with additives are detailed. Hub additionally restricts heat flow due to its maximised length and minimised cross-section, the reduced area bosses further restricting surface contact. (author)

Stationary Magnetohydrodynamic Models of Three-Dimensional Rigidly Rotating Magnetized Coronae

International Nuclear Information System (INIS)

Al-Salti, Nasser; Neukirch, Thomas

2009-01-01

Example solutions of a theory for stationary 3D non-potential solutions of the MHD equations (in the co-rotating frame of reference) are presented. As a first step we present solutions for the mathematically simpler case of a massive central cylinder, but the theory can also be applied to spherical bodies. The fundamental equation of the theory is linear and in the cylindrical case it can be solved using standard methods. Possible application is the structure of coronae of (fast) rotating stars.

Solid deuterium centrifuge pellet injector

International Nuclear Information System (INIS)

Foster, C.A.

1982-01-01

Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength KEVLAR/epoxy composite. This arbon has been spin-tested to a tip speed of 1 km/s

Solid deuterium centrifuge pellet injector

International Nuclear Information System (INIS)

Foster, C.A.

1983-01-01

Pellet injectors are needed to fuel long pulse tokamak plasmas and other magnetic confinement devices. For this purpose, an apparatus has been developed that forms 1.3-mm-diam pellets of frozen deuterium at a rate of 40 pellets per second and accelerates them to a speed of 1 km/s. Pellets are formed by extruding a billet of solidified deuterium through a 1.3-mm-diam nozzle at a speed of 5 cm/s. The extruding deuterium is chopped with a razor knife, forming 1.3-mm right circular cylinders of solid deuterium. The pellets are accelerated by synchronously injecting them into a high speed rotating arbor containing a guide track, which carries them from a point near the center of rotation to the periphery. The pellets leave the wheel after 150 0 of rotation at double the tip speed. The centrifuge is formed in the shape of a centrifugal catenary and is constructed of high strength Kevlar/epoxy composite. This arbor has been spin-tested to a tip speed of 1 km/s

Analysis of semi-solid processing for metal matrix composite synthesis using factorial design

Directory of Open Access Journals (Sweden)

Kratus Ranieri

2012-02-01

Full Text Available The main goal in this work is to conduct a quantitative analysis of the mechanical stir casting process for obtaining particulate metal matrix composites. A combined route of stirring at semi-solid state followed by stirring at liquid state is proposed. A fractional factorial design was developed to investigate the influence and interactions of factors as: time, rotation, initial fraction and particle size, on the incorporated fraction. The best incorporations were obtained with all factors at high levels, as well as that very long stirring periods have no strong influence being particle size and rotation the most important factors on the incorporated fraction. Particle wetting occurs during stirring at semi-solid state, highlighting the importance of the interactions between particles and the alloy globularized phase. The role of the alloying element Mg as a wettability-promoting agent is discussed. The shear forces resulting from the stirring system is emphasized and understood as the effect of rotation itself added to the propeller blade geometry.

On the atmosphere of a moving body

DEFF Research Database (Denmark)

Pedersen, Johan Rønby; Aref, Hassan

2010-01-01

We explore whether a rigid body moving freely with no circulation around it in a two-dimensional ideal fluid can carry a fluid "atmosphere" with it in its motion. Somewhat surprisingly, the answer appears to be "yes." When the body is elongated and the motion is dominated by rotation, we demonstr...

On the atmosphere of a moving body

DEFF Research Database (Denmark)

Pedersen, Johan Rønby; Aref, Hassan

2010-01-01

We have explored whether a rigid body moving freely with no circulation around it in a two-dimensional ideal fluid can carry a fluid ``atmosphere'' with it in its motion. Somewhat surprisingly, the answer appears to be ``yes''. When the body is elongated and the motion is dominated by rotation, w...

Wave-driven Rotation in Supersonically Rotating Mirrors

Energy Technology Data Exchange (ETDEWEB)

A. Fetterman and N.J. Fisch

2010-02-15

Supersonic rotation in mirrors may be produced by radio frequency waves. The waves produce coupled diffusion in ion kinetic and potential energy. A population inversion along the diffusion path then produces rotation. Waves may be designed to exploit a natural kinetic energy source or may provide the rotation energy on their own. Centrifugal traps for fusion and isotope separation may benefit from this wave-driven rotation.

Wave-driven Rotation in Supersonically Rotating Mirrors

International Nuclear Information System (INIS)

Fetterman, A.; Fisch, N.J.

2010-01-01

Supersonic rotation in mirrors may be produced by radio frequency waves. The waves produce coupled diffusion in ion kinetic and potential energy. A population inversion along the diffusion path then produces rotation. Waves may be designed to exploit a natural kinetic energy source or may provide the rotation energy on their own. Centrifugal traps for fusion and isotope separation may benefit from this wave-driven rotation.

Kinematics of Deformation in West-Central Walker Lane; Paleomagnetic Testing of Fault-Block Rotation and Doming Models, Eastern California and Western Nevada

Science.gov (United States)

Fredrickson, S. M.; Pluhar, C. J.; Carlson, C. W.

2013-12-01

Walker Lane is a broad (~100-200 km) zone of dextral shear located between the Sierra Nevada microplate and the Basin and Range Province. We consider Bodie Hills a part of the greater Walker Lane because it has experienced clockwise, vertical-axis rotation of crustal blocks due to dextral shear accommodation. This strain is variable, resulting in rotations ranging from ~10°-70° depending on location. The Miocene Eureka Valley Tuff (EVT) is an ideal strain marker, because it is a geologically instantaneous and laterally extensive unit. We use paleomagnetic analysis of ignimbrites to improve the resolution of strain domain boundaries as well as test for doming in Bodie Hills. EVT site mean directions were compared to reference directions of the Tollhouse Flat and By Day Members collected from the stable Sierra Nevada to determine magnitudes of vertical-axis rotation. Three new sites and three previously sampled sites define a high-rotation domain including Bridgeport Valley and the East Walker River Canyon with an average clockwise rotation of ~50°-60°. We define the eastern boundary of this high-rotation domain as coinciding with a mapped fault exhibiting 11.7°×7.9° rotation of the presumed footwall. Our data corroborates and improves on Carlson's (2012) kinematic model in which the greater Bodie Hills has rotated clockwise ~30° since EVT emplacement. Eutaxitic textures, dipping up to 90°, are gross indicators of true tilt, but are also influenced by original dips in some localities, complicating interpretations. John et al. (2012) describe a simple doming model of Bodie Hills since EVT emplacement, supported by the high elevation of outflow channels compared to source areas. Our paleomagnetic data does not support simple doming, suggesting that there is either no doming of Bodie Hills, or that vertical crustal displacements have occurred without large-scale folding. John et al. (2012) dated undifferentiated EVT in Bodie Hills at ~9.4 Ma; using

A Fully Nonlinear, Dynamically Consistent Numerical Model for Solid-Body Ship Motion. I. Ship Motion with Fixed Heading

Science.gov (United States)

Lin, Ray-Quing; Kuang, Weijia

2011-01-01

In this paper, we describe the details of our numerical model for simulating ship solidbody motion in a given environment. In this model, the fully nonlinear dynamical equations governing the time-varying solid-body ship motion under the forces arising from ship wave interactions are solved with given initial conditions. The net force and moment (torque) on the ship body are directly calculated via integration of the hydrodynamic pressure over the wetted surface and the buoyancy effect from the underwater volume of the actual ship hull with a hybrid finite-difference/finite-element method. Neither empirical nor free parametrization is introduced in this model, i.e. no a priori experimental data are needed for modelling. This model is benchmarked with many experiments of various ship hulls for heave, roll and pitch motion. In addition to the benchmark cases, numerical experiments are also carried out for strongly nonlinear ship motion with a fixed heading. These new cases demonstrate clearly the importance of nonlinearities in ship motion modelling.

an empirical study exploring body perception and apparel fit

African Journals Online (AJOL)

user

3D rotational point cloud surface image derived from 3D body scans ... Furthermore, recent advances in technology, such as 3D ... up-to-date and, accessible apparel sizing or body dimension ... manufacturing companies and retailers, and not.

Surprisingly different star-spot distributions on the near equal-mass equal-rotation-rate stars in the M dwarf binary GJ 65 AB

Science.gov (United States)

Barnes, J. R.; Jeffers, S. V.; Haswell, C. A.; Jones, H. R. A.; Shulyak, D.; Pavlenko, Ya. V.; Jenkins, J. S.

2017-10-01

We aim to understand how stellar parameters such as mass and rotation impact the distribution of star-spots on the stellar surface. To this purpose, we have used Doppler imaging to reconstruct the surface brightness distributions of three fully convective M dwarfs with similar rotation rates. We secured high cadence spectral time series observations of the 5.5 au separation binary GJ 65, comprising GJ 65A (M5.5V, Prot = 0.24 d) and GJ 65B (M6V, Prot = 0.23 d). We also present new observations of GJ 791.2A (M4.5V, Prot = 0.31 d). Observations of each star were made on two nights with UVES, covering a wavelength range from 0.64 - 1.03μm. The time series spectra reveal multiple line distortions that we interpret as cool star-spots and which are persistent on both nights suggesting stability on the time-scale of 3 d. Spots are recovered with resolutions down to 8.3° at the equator. The global spot distributions for GJ 791.2A are similar to observations made a year earlier. Similar high latitude and circumpolar spot structure is seen on GJ 791.2A and GJ 65A. However, they are surprisingly absent on GJ 65B, which instead reveals more extensive, larger, spots concentrated at intermediate latitudes. All three stars show small amplitude latitude-dependent rotation that is consistent with solid body rotation. We compare our measurements of differential rotation with previous Doppler imaging studies and discuss the results in the wider context of other observational estimates and recent theoretical predictions.

X-ray tube rotating anode

International Nuclear Information System (INIS)

Friedel, R.

1979-01-01

The anode disk of the X-ray rotating anode is blackened on the surface outside the focal spot tracks in order to improve the heat radiation. In particular the side opposite the focal spot tracks is provided with many small holes, the ratio of depth to cross-section ('pit ratio') being as large as possible: ranging from 2:1 to 10:1. They are arranged so densely that the radiating surface will nearly have the effect of a black body. (RW) [de

Rotational particle separator: A new method for separating fine particles and mist from gases

NARCIS (Netherlands)

Brouwers, J.J.H.

1996-01-01

An account is given of the patented technique of the rotational particle separator for separating solid and liquid particles of diameter 0.1 µm and larger from gases. Attention is focused on the working principle, fluid mechanical constraints, particle design, separation performance, power

Rotational particle separator: A new method for separating fine particles and mists from gases

NARCIS (Netherlands)

Brouwers, J.J.H.

1996-01-01

An account is given of the patented technique of the rotational particle separator for separating solid and liquid particles of diameter 0.1 µm and larger from gases. Attention is focussed on the working principle, fluid mechanical constraints, practical designs, separation performance, power

Rotating flow

CERN Document Server

Childs, Peter R N

2010-01-01

Rotating flow is critically important across a wide range of scientific, engineering and product applications, providing design and modeling capability for diverse products such as jet engines, pumps and vacuum cleaners, as well as geophysical flows. Developed over the course of 20 years' research into rotating fluids and associated heat transfer at the University of Sussex Thermo-Fluid Mechanics Research Centre (TFMRC), Rotating Flow is an indispensable reference and resource for all those working within the gas turbine and rotating machinery industries. Traditional fluid and flow dynamics titles offer the essential background but generally include very sparse coverage of rotating flows-which is where this book comes in. Beginning with an accessible introduction to rotating flow, recognized expert Peter Childs takes you through fundamental equations, vorticity and vortices, rotating disc flow, flow around rotating cylinders and flow in rotating cavities, with an introduction to atmospheric and oceanic circul...

Rotational seismology

Science.gov (United States)

Lee, William H K.

2016-01-01

Rotational seismology is an emerging study of all aspects of rotational motions induced by earthquakes, explosions, and ambient vibrations. It is of interest to several disciplines, including seismology, earthquake engineering, geodesy, and earth-based detection of Einstein’s gravitation waves.Rotational effects of seismic waves, together with rotations caused by soil–structure interaction, have been observed for centuries (e.g., rotated chimneys, monuments, and tombstones). Figure 1a shows the rotated monument to George Inglis observed after the 1897 Great Shillong earthquake. This monument had the form of an obelisk rising over 19 metres high from a 4 metre base. During the earthquake, the top part broke off and the remnant of some 6 metres rotated about 15° relative to the base. The study of rotational seismology began only recently when sensitive rotational sensors became available due to advances in aeronautical and astronomical instrumentations.

Report of the IAU Working Group on cartographic coordinates and rotational elements: 2009

Science.gov (United States)

Archinal, Brent A.; A’Hearn, Michael F.; Bowell, Edward; Conrad, Al; Consolmagno, Guy J.; Courtin, Regis; Fukushima, Toshio; Hestroffer, Daniel; Hilton, James L.; Krasinsky, Georgij A.; Neumann, Gregory; Oberst, Jurgen; Seidelmann, P. Kenneth; Stooke, Philip; Tholen, David J.; Thomas, Peter C.; Williams, Iwan P.

2010-01-01

Every three years the IAU Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report takes into account the IAU Working Group for Planetary System Nomenclature (WGPSN) and the IAU Committee on Small Body Nomenclature (CSBN) definition of dwarf planets, introduces improved values for the pole and rotation rate of Mercury, returns the rotation rate of Jupiter to a previous value, introduces improved values for the rotation of five satellites of Saturn, and adds the equatorial radius of the Sun for comparison. It also adds or updates size and shape information for the Earth, Mars’ satellites Deimos and Phobos, the four Galilean satellites of Jupiter, and 22 satellites of Saturn. Pole, rotation, and size information has been added for the asteroids (21) Lutetia, (511) Davida, and (2867) Šteins. Pole and rotation information has been added for (2) Pallas and (21) Lutetia. Pole and rotation and mean radius information has been added for (1) Ceres. Pole information has been updated for (4) Vesta. The high precision realization for the pole and rotation rate of the Moon is updated. Alternative orientation models for Mars, Jupiter, and Saturn are noted. The Working Group also reaffirms that once an observable feature at a defined longitude is chosen, a longitude definition origin should not change except under unusual circumstances. It is also noted that alternative coordinate systems may exist for various (e.g. dynamical) purposes, but specific cartographic coordinate system information continues to be recommended for each body. The Working Group elaborates on its purpose, and also announces its plans to occasionally provide limited updates to its recommendations via its website, in order to address community needs for some updates more often than every 3 years. Brief recommendations are also made to the

Report of the IAU Working Group on cartographic coordinates and rotational elements: 2009

Science.gov (United States)

Archinal, B.A.; A'Hearn, M.F.; Bowell, E.; Conrad, A.; Consolmagno, G.J.; Courtin, R.; Fukushima, T.; Hestroffer, D.; Hilton, J.L.; Krasinsky, G.A.; Neumann, G.; Oberst, J.; Seidelmann, P.K.; Stooke, P.; Tholen, D.J.; Thomas, P.C.; Williams, I.P.

2010-01-01

Every three years the IAU Working Group on Cartographic Coordinates and Rotational Elements revises tables giving the directions of the poles of rotation and the prime meridians of the planets, satellites, minor planets, and comets. This report takes into account the IAU Working Group for Planetary System Nomenclature (WGPSN) and the IAU Committee on Small Body Nomenclature (CSBN) definition of dwarf planets, introduces improved values for the pole and rotation rate of Mercury, returns the rotation rate of Jupiter to a previous value, introduces improved values for the rotation of five satellites of Saturn, and adds the equatorial radius of the Sun for comparison. It also adds or updates size and shape information for the Earth, Mars’ satellites Deimos and Phobos, the four Galilean satellites of Jupiter, and 22 satellites of Saturn. Pole, rotation, and size information has been added for the asteroids (21) Lutetia, (511) Davida, and (2867) Šteins. Pole and rotation information has been added for (2) Pallas and (21) Lutetia. Pole and rotation and mean radius information has been added for (1) Ceres. Pole information has been updated for (4) Vesta. The high precision realization for the pole and rotation rate of the Moon is updated. Alternative orientation models for Mars, Jupiter, and Saturn are noted. The Working Group also reaffirms that once an observable feature at a defined longitude is chosen, a longitude definition origin should not change except under unusual circumstances. It is also noted that alternative coordinate systems may exist for various (e.g. dynamical) purposes, but specific cartographic coordinate system information continues to be recommended for each body. The Working Group elaborates on its purpose, and also announces its plans to occasionally provide limited updates to its recommendations via its website, in order to address community needs for some updates more often than every 3 years. Brief recommendations are also made to the general

On effects of topography in rotating flows

Science.gov (United States)

Burmann, Fabian; Noir, Jerome; Jackson, Andrew

2017-11-01

Both, seismological studies and geodynamic arguments suggest that there is significant topography at the core mantle boundary (CMB). This leads to the question whether the topography of the CMB could influence the flow in the Earth's outer core. As a preliminary experiment, we investigate the effects of bottom topography in the so-called Spin-Up, where motion of a contained fluid is created by a sudden increase of rotation rate. Experiments are performed in a cylindrical container mounted on a rotating table and quantitative results are obtained with particle image velocimetry. Several horizontal length scales of topography (λ) are investigated, ranging from cases where λ is much smaller then the lateral extend of the experiment (R) to cases where λ is a fraction of R. We find that there is an optimal λ that creates maximum dissipation of kinetic energy. Depending on the length scale of the topography, kinetic energy is either dissipated in the boundary layer or in the bulk of the fluid. Two different phases of fluid motion are present: a starting flow in the from of solid rotation (phase I), which is later replaced by meso scale vortices on the length scale of bottom topography (phase II).

Rotational instability in a linear theta pinch

International Nuclear Information System (INIS)

Ekdahl, C.; Bartsch, R.R.; Commisso, R.J.; Gribble, R.F.; McKenna, K.F.; Miller, G.; Siemon, R.E.

1980-01-01

The m=1 ''wobble'' instability of the plasma column in a 5-m linear theta pinch has been studied using an axial array of orthogonally viewing position detectors to resolve the wavelength and frequency of the column motion. The experimental results are compared with recent theoretical predictions that include finite Larmor orbit effects. The frequency and wavelength characteristics at saturation agree with the predicted dispersion relation for a plasma rotating faster than the diamagnetic drift speed. Measurements of the magnetic fields at the ends of the pinch establish the existence of currents flowing in such a way that they short out the radial electric fields in the plasma column. The magnitude of rotation, the observed delay in the onset of m=1 motion, and the magnitude of end-shorting currents can all be understood in terms of the torsional Alfven waves that communicate to the central plasma column the information that the ends have been shorted. The same waves are responsible for the torque which rotates the plasma and leads to the observed m=1 instability. Observations of the plasma in the presence of solid end plugs indicate a stabilization of high-m number modes and a reduction of the m=1 amplitude

Density-functional theory for fluid-solid and solid-solid phase transitions.

Science.gov (United States)

Bharadwaj, Atul S; Singh, Yashwant

2017-03-01

We develop a theory to describe solid-solid phase transitions. The density functional formalism of classical statistical mechanics is used to find an exact expression for the difference in the grand thermodynamic potentials of the two coexisting phases. The expression involves both the symmetry conserving and the symmetry broken parts of the direct pair correlation function. The theory is used to calculate phase diagram of systems of soft spheres interacting via inverse power potentials u(r)=ε(σ/r)^{n}, where parameter n measures softness of the potential. We find that for 1/nfcc) structure while for 1/n≥0.154 the body-centred-cubic (bcc) structure is preferred. The bcc structure transforms into the fcc structure upon increasing the density. The calculated phase diagram is in good agreement with the one found from molecular simulations.

The research of the coupled orbital-attitude controlled motion of celestial body in the neighborhood of the collinear libration point L1

Science.gov (United States)

Shmyrov, A.; Shmyrov, V.; Shymanchuk, D.

2017-10-01

This article considers the motion of a celestial body within the restricted three-body problem of the Sun-Earth system. The equations of controlled coupled attitude-orbit motion in the neighborhood of collinear libration point L1 are investigated. The translational orbital motion of a celestial body is described using Hill's equations of circular restricted three-body problem of the Sun-Earth system. Rotational orbital motion is described using Euler's dynamic equations and quaternion kinematic equation. We investigate the problem of stability of celestial body rotational orbital motion in relative equilibrium positions and stabilization of celestial body rotational orbital motion with proposed control laws in the neighborhood of collinear libration point L1. To study stabilization problem, Lyapunov function is constructed in the form of the sum of the kinetic energy and special "kinematic function" of the Rodriguez-Hamiltonian parameters. Numerical modeling of the controlled rotational motion of a celestial body at libration point L1 is carried out. The numerical characteristics of the control parameters and rotational motion are given.

Necessary conditions for tumbling in the rotational motion

Science.gov (United States)

Carrera, Danny H. Z.; Weber, Hans I.

2012-11-01

The goal of this work is the investigation of the necessary conditions for the possible existence of tumbling in rotational motion of rigid bodies. In a stable spinning satellite, tumbling may occur by sufficient strong action of external impulses, when the conical movement characteristic of the stable attitude is de-characterized. For this purpose a methodology is chosen to simplify the study of rotational motions with great amplitude, for example free bodies in space, allowing an extension of the analysis to non-conservative systems. In the case of a satellite in space, the projection of the angular velocity along the principal axes of inertia must be known, defining completely the initial conditions of motion for stability investigations. In this paper, the coordinate systems are established according to the initial condition in order to allow a simple analytical work on the equations of motion. Also it will be proposed the definition of a parameter, calling it tumbling coefficient, to measure the intensity of the tumbling and the amplitude of the motion when crossing limits of stability in the concept of Lyapunov. Tumbling in the motion of bodies in space is not possible when this coefficient is positive. Magnus Triangle representation will be used to represent the geometry of the body, establishing regions of stability/instability for possible initial conditions of motion. In the study of nonconservative systems for an oblate body, one sufficient condition will be enough to assure damped motion, and this condition is checked for a motion damped by viscous torques. This paper seeks to highlight the physical understanding of the phenomena and the influence of various parameters that are important in the process.

Faraday rotation echo spectroscopy and detection of quantum fluctuations.

Science.gov (United States)

Chen, Shao-Wen; Liu, Ren-Bao

2014-04-15

Central spin decoherence is useful for detecting many-body physics in environments and moreover, the spin echo control can remove the effects of static thermal fluctuations so that the quantum fluctuations are revealed. The central spin decoherence approach, however, is feasible only in some special configurations and often requires uniform coupling between the central spin and individual spins in the baths, which are very challenging in experiments. Here, by making analogue between central spin decoherence and depolarization of photons, we propose a scheme of Faraday rotation echo spectroscopy (FRES) for studying quantum fluctuations in interacting spin systems. The echo control of the photon polarization is realized by flipping the polarization with a birefringence crystal. The FRES, similar to spin echo in magnetic resonance spectroscopy, can suppress the effects of the static magnetic fluctuations and therefore reveal dynamical magnetic fluctuations. We apply the scheme to a rare-earth compound LiHoF4 and calculate the echo signal, which is related to the quantum fluctuations of the system. We observe enhanced signals at the phase boundary. The FRES should be useful for studying quantum fluctuations in a broad range of spin systems, including cold atoms, quantum dots, solid-state impurities, and transparent magnetic materials.

In-to-out body path loss for wireless radio frequency capsule endoscopy in a human body.

Science.gov (United States)

Vermeeren, G; Tanghe, E; Thielens, A; Martens, L; Joseph, W

2016-08-01

Physical-layer characterization is important for design of in-to-out body communication for wireless body area networks (WBANs). This paper numerically investigates the path loss of an in-to-out body radio frequency (RF) wireless link between an endoscopy capsule and a receiver outside the body using a 3D electromagnetic solver. A spiral antenna in the endoscopy capsule is tuned to operate in the Medical Implant Communication Service (MICS) band at 402 MHz, accounting for the properties of the human body. The influence of misalignment, rotation of the capsule, and human body model are investigated. Semi-empirical path loss models for various homogeneous tissues and 3D realistic human body models are provided for manufacturers to evaluate the performance of in-to-out-body WBAN systems.

Novel Plasmid Transformation Method Mediated by Chrysotile, Sliding Friction, and Elastic Body Exposure

Directory of Open Access Journals (Sweden)

Naoto Yoshida

2007-01-01

Full Text Available Escherichia coli as a plasmid recipient cell was dispersed in a chrysotile colloidal solution, containing chrysotile adsorbed to plasmid DNA (chrysotile-plasmid cell mixture. Following this, the chrysotile-plasmid cell mixture was dropped onto the surface of an elastic body, such as agarose, and treated physically by sliding a polystyrene streak bar over the elastic body to create friction. Plasmid DNA was easily incorporated into E. coli, and antibiotic resistance was conferred by transformation. The transformation efficiency of E. coli cultured in solid medium was greater than that of E. coli cultured in broth. To obtain greater transformation efficiency, we attempted to determine optimal transformation conditions. The following conditions resulted in the greatest transformation efficiency: the recipient cell concentration within the chrysotileplasmid cell mixture had an optical density greater than or equal to 2 at 550 nm, the vertical reaction force applied to the streak bar was greater than or equal to 40 g, and the rotation speed of the elastic body was greater than or equal to 34 rpm. Under these conditions, we observed a transformation efficiency of 107 per μg plasmid DNA. The advantage of achieving bacterial transformation using the elastic body exposure method is that competent cell preparation of the recipient cell is not required. In addition to E. coli, other Gram negative bacteria are able to acquire plasmid DNA using the elastic body exposure method.

Rigid body formulation in a finite element context with contact interaction

Science.gov (United States)

Refachinho de Campos, Paulo R.; Gay Neto, Alfredo

2018-03-01

The present work proposes a formulation to employ rigid bodies together with flexible bodies in the context of a nonlinear finite element solver, with contact interactions. Inertial contributions due to distribution of mass of a rigid body are fully developed, considering a general pole position associated with a single node, representing a rigid body element. Additionally, a mechanical constraint is proposed to connect a rigid region composed by several nodes, which is useful for linking rigid/flexible bodies in a finite element environment. Rodrigues rotation parameters are used to describe finite rotations, by an updated Lagrangian description. In addition, the contact formulation entitled master-surface to master-surface is employed in conjunction with the rigid body element and flexible bodies, aiming to consider their interaction in a rigid-flexible multibody environment. New surface parameterizations are presented to establish contact pairs, permitting pointwise interaction in a frictional scenario. Numerical examples are provided to show robustness and applicability of the methods.

Rotation technique for irradiation of the bladder and the results obtained

Energy Technology Data Exchange (ETDEWEB)

Backhouse, T W [Coventry and Warwickshire Hospital (UK). Dept. of Radiotherapy and Oncology

1979-05-01

An argument is advanced for the use of partial rotational techniques for the treatment of carcinoma of the bladder. One hundred and seventy cases are analysed; the majority were T3 solid transitional cell lesions with an overall (corrected) survival rate of 24.7%. Salvage cystectomy produced a four-year survival rate of 40% when performed within six months of the radiotherapy.

Measurements of plasma rotation in an axially magnetized MPD arc-jet

Energy Technology Data Exchange (ETDEWEB)

Tobari, Hiroyuki; Ashino, Masashi; Yoshino, Kyohei; Sagi, Yukiko; Yoshinuma, Mikirou; Hattori, Kunihiko; Ando, Akira; Inutake, Masaaki [Department of Electrical Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi (Japan)

2001-01-24

Characteristics of an axially magnetized MPD (magneto-plasma-dynamic) arcjet plasma are investigated by spectroscopy on the HITOP (High density of Tohoku Plasma) device in Tohoku University. Plasma flow and rotational velocity and temperature of He ion and atom near the muzzle region of MPD arcjet are measured by Doppler shift and broadening of the HeI ({lambda}=578.56 nm) and HeII ({lambda}=468.58 nm) lines. From the measured radial profile of rotational velocity and temperature of He ion, the radial profiles of electrical field and space potential are calculated and it has been found that the potential profile in the core region is parabolic, which shows the plasma rotates as a rigid body. (author)

Contacting solids and liquids

International Nuclear Information System (INIS)

Robinson, L.F.

1980-01-01

A solids/liquid (or slurry/liquid) contactor is described comprising a container through which the phases flow, rotatable discs with a rotor dividing the container into a series of interconnected compartments and, in at least some of the compartments, receptacles extending between the discs to effect phase transfer. At least one of the compartments is free of receptacles or has receptacles arranged on a smaller diameter than in other compartments to form a settling chamber. The contactor may be used in the extraction of oil-sands or uranium or purification of china clay. (author)

Solid hydrogen-plasma interaction

International Nuclear Information System (INIS)

Joergensen, L.W.

1976-03-01

A review of the need of refuelling fusion reactors and of the possible refuelling methods, in particular injection of pellets of solid hydrogen isotopes, is given. The interaction between hydrogen pellets and a fusion plasma is investigated and a theoretical model is given. From this it is seen that the necessary injected speed is above 10 4 m/sec. Experiments in which hydrogen pellets are interacting with a rotating test plasma (puffatron plasma) is described. The experimental results partly verify the basic ideas of the theoretical model. (Auth.)

The Role of Motor Processes in Three-Dimensional Mental Rotation: Shaping Cognitive Processing via Sensorimotor Experience

Science.gov (United States)

Moreau, David

2012-01-01

An extensive body of literature has explored the involvement of motor processes in mental rotation, yet underlying individual differences are less documented and remain to be fully understood. We propose that sensorimotor experience shapes spatial abilities such as assessed in mental rotation tasks. Elite wrestlers' and non-athletes' mental…

Embodied mental rotation: A special link between egocentric transformation and the bodily self

Directory of Open Access Journals (Sweden)

Sandra eKaltner

2014-06-01

Full Text Available This experiment investigated the influence of motor expertise on object-based versus egocentric transformations in a chronometric mental rotation task using images of either the own or another person’s body as stimulus material. According to the embodied cognition viewpoint, we hypothesized motor-experts to outperform non-motor experts specifically in the egocentric condition because of higher kinesthetic representation and motor simulations compared to object-based transformations. In line with this, we expected that images of the own body are solved faster than another person’s body stimuli. Results showed a benefit of motor expertise and representations of another person’s body, but only for the object-based transformation task. That is, this other-advantage diminishes in egocentric transformations. Since motor experts didn’t show any specific expertise in rotational movements, we concluded that using human bodies as stimulus material elicits embodied spatial transformations, which facilitates performance exclusively for egocentric transformations. Regarding stimulus material, the other-advantage ascribed to increased self-awareness-consciousness distracting attention-demanding resources, disappeared in the egocentric condition. This result may be due to the stronger link between the bodily self and motor representations compared to that emerging in object-based transformations.

Foreign Body Retrieval

Medline Plus

Full Text Available ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ... Anesthesia Safety X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Videos related to Foreign Body Retrieval ...

Foreign Body Retrieval

Medline Plus

Full Text Available ... sends out high-frequency sound waves (that the human ear cannot hear) into the body and then ... object is solid or filled with fluid). In medicine, ultrasound is used to detect changes in appearance, ...

Global rotation

International Nuclear Information System (INIS)

Rosquist, K.

1980-01-01

Global rotation in cosmological models is defined on an observational basis. A theorem is proved saying that, for rigid motion, the global rotation is equal to the ordinary local vorticity. The global rotation is calculated in the space-time homogeneous class III models, with Godel's model as a special case. It is shown that, with the exception of Godel's model, the rotation in these models becomes infinite for finite affine parameter values. In some directions the rotation changes sign and becomes infinite in a direction opposite to the local vorticity. The points of infinite rotation are identified as conjugate points along the null geodesics. The physical interpretation of the infinite rotation is discussed, and a comparison with the behaviour of the area distance at conjugate points is given. (author)

SU-E-J-170: Dosimetric Consequences of Uncorrected Rotational Setup Errors During Stereotactic Body Radiation Therapy (SBRT) Treatment of Pancreatic Cancers

Energy Technology Data Exchange (ETDEWEB)

Di Maso, L [Chicago, IL (United States); Forbang, R Teboh; Zhang, Y; Herman, J; Lee, J [John Hopkins University, Baltimore, MD (United States)

2015-06-15

Purpose: To explore the dosimetric consequences of uncorrected rotational setup errors during SBRT for pancreatic cancer patients. Methods: This was a retrospective study utilizing data from ten (n=10) previously treated SBRT pancreas patients. For each original planning CT, we applied rotational transformations to derive additional CT images representative of possible rotational setup errors. This resulted in 6 different sets of rotational combinations, creating a total of 60 CT planning images. The patients’ clinical dosimetric plans were then applied to their corresponding rotated CT images. The 6 rotation sets encompassed a 3, 2 and 1-degree rotation in each rotational direction and a 3-degree in just the pitch, a 3-degree in just the yaw and a 3-degree in just the roll. After the dosimetric plan was applied to the rotated CT images, the resulting plan was then evaluated and compared with the clinical plan for tumor coverage and normal tissue sparing. Results: PTV coverage, defined here by V33 throughout all of the patients’ clinical plans, ranged from 92–98%. After an n degree rotation in each rotational direction that range decreased to 68–87%, 85–92%, and 88– 94% for n=3, 2 and 1 respectively. Normal tissue sparing defined here by the proximal stomach V15 throughout all of the patients’ clinical plans ranged from 0–8.9 cc. After an n degree rotation in each rotational direction that range increased to 0–17 cc, 0–12 cc, and 0–10 cc for n=3, 2, and 1 respectively. Conclusion: For pancreatic SBRT, small rotational setup errors in the pitch, yaw and roll direction on average caused under dosage to PTV and over dosage to proximal normal tissue. The 1-degree rotation was on average the least detrimental to the normal tissue and the coverage of the PTV. The 3-degree yaw created on average the lowest increase in volume coverage to normal tissue. This research was sponsored by the AAPM Education Council through the AAPM Education and Research

Misalignment Effect Function Measurement for Oblique Rotation Axes: Counterintuitive Predictions and Theoretical Extensions

Science.gov (United States)

Ellis, Stephen R.; Adelstein, Bernard D.; Yeom, Kiwon

2013-01-01

The Misalignment Effect Function (MEF) describes the decrement in manual performance associated with a rotation between operators' visual display frame of reference and that of their manual control. It now has been empirically determined for rotation axes oblique to canonical body axes and is compared with the MEF previously measured for rotations about canonical axes. A targeting rule, called the Secant Rule, based on these earlier measurements is derived from a hypothetical process and shown to describe some of the data from three previous experiments. It explains the motion trajectories determined for rotations less than 65deg in purely kinematic terms without the need to appeal to a mental rotation process. Further analysis of this rule in three dimensions applied to oblique rotation axes leads to a somewhat surprising expectation that the difficulty posed by rotational misalignment should get harder as the required movement is shorter. This prediction is confirmed. Geometry underlying this rule also suggests analytic extensions for predicting more generally the difficulty of making movements in arbitrary directions subject to arbitrary misalignments.

Vibrational Suspension of Light Sphere in a Tilted Rotating Cylinder with Liquid

Directory of Open Access Journals (Sweden)

Victor G. Kozlov

2014-01-01

Full Text Available The dynamics of a light sphere in a quickly rotating inclined cylinder filled with liquid under transversal vibrations is experimentally investigated. Due to inertial oscillations of the sphere relative to the cavity, its rotation velocity differs from the cavity one. The intensification of the lagging motion of a sphere and the excitation of the outstripping differential rotation are possible under vibrations. It occurs in the resonant areas where the frequency of vibrations coincides with the fundamental frequency of the system. The position of the sphere in the center of the cylinder could be unstable. Different velocities of the sphere are matched with its various quasistationary positions on the axis of rotating cavity. In tilted rotating cylinder, the axial component of the gravity force appears; however, the light sphere does not float to the upper end wall but gets the stable position at a definite distance from it. It makes possible to provide a vibrational suspension of the light sphere in filled with liquid cavity rotating around the vertical axis. It is found that in the wide range of the cavity inclination angles the sphere position is determined by the dimensionless velocity of body differential rotation.

Semiclassical shell structure in rotating Fermi systems

International Nuclear Information System (INIS)

Magner, A. G.; Sitdikov, A. S.; Khamzin, A. A.; Bartel, J.

2010-01-01

The collective moment of inertia is derived analytically within the cranking model for any rotational frequency of the harmonic-oscillator potential well and at a finite temperature. Semiclassical shell-structure components of the collective moment of inertia are obtained for any potential by using the periodic-orbit theory. We found semiclassically their relation to the free-energy shell corrections through the shell-structure components of the rigid-body moment of inertia of the statistically equilibrium rotation in terms of short periodic orbits. The shell effects in the moment of inertia exponentially disappear with increasing temperature. For the case of the harmonic-oscillator potential, one observes a perfect agreement of the semiclassical and quantum shell-structure components of the free energy and the moment of inertia for several critical bifurcation deformations and several temperatures.

Rotating drum tests of particle suspensions within a fines dispersion

Science.gov (United States)

Cabrera, Miguel Angel; Gollin, Devis; Kaitna, Roland; Wu, Wei

2014-05-01

Natural flows like mudflows, debris flow, and hyperconcentrated flows are commonly composed by a matrix of particles suspended in a viscous fluid. The nature of the interactions between particles immersed in a fluid is related to its size. While coarse particles (sand, gravel, and boulders) interact with each other or with the surrounding fluid, a dispersion of fine particles interacts with each other through colloidal forces or Brownian motion effects (Coussot and Piau, 1995, and Ancey and Jorrot, 2001). The predominance of one of the previous interactions defines the rheology of the flow. On this sense, experimental insight is required to validate the limits where the rheology of a dispersion of fines is valid. For this purpose, an experimental program in a rotating drum is performed over samples of sand, loess, and kaolin. The solid concentration and angular velocity of the rotating drum are varied. Height and normal loads are measured during flow. High-speed videos are performed to obtain the flow patterns of the mixtures. The experiments provide new laboratory evidence of granular mixture behaviour within an increased viscous fluid phase and its characterization. The results show an apparent threshold in terms of solid concentration, in which the mixtures started to behave as a shear-dependent material.

Determination of a sagittal plane axis of rotation for a dynamic office chair.

Science.gov (United States)

Bauer, C M; Rast, F M; Böck, C; Kuster, R P; Baumgartner, D

2018-10-01

This study investigated the location of the axis of rotation in sagittal plane movement of the spine in a free sitting condition to adjust the kinematics of a mobile seat for a dynamic chair. Dynamic office chairs are designed to avoid continuous isometric muscle activity, and to facilitate increased mobility of the back during sitting. However, these chairs incorporate increased upper body movement which could distract office workers from the performance of their tasks. A chair with an axis of rotation above the seat would facilitate a stable upper back during movements of the lower back. The selection of a natural kinematic pattern is of high importance in order to match the properties of the spine. Twenty-one participants performed four cycles of flexion and extension of the spine during an upper arm hang on parallel bars. The location of the axis of rotation relative to the seat was estimated using infrared cameras and reflective skin markers. The median axis of rotation across all participants was located 36 cm above the seat for the complete movement and 39 cm for both the flexion and extension phases, each with an interquartile range of 20 cm. There was no significant effect of the movement direction on the location of the axis of rotation and only a weak, non-significant correlation between body height and the location of the axis of rotation. Individual movement patterns explained the majority of the variance. The axis of rotation for a spinal flexion/extension movement is located above the seat. The recommended radius for a guide rail of a mobile seat is between 36 cm and 39 cm. Copyright © 2018 Elsevier Ltd. All rights reserved.

IVABRADINE LOADED SOLID LIPID MICROPARTICLES: FORMULATION, CHARACTERIZATION AND OPTIMIZATION BY CENTRAL COMPOSITE ROTATABLE DESIGN.

Science.gov (United States)

Hanif, Muhammad; Khan, Hafeez Ullah; Afzal, Samina; Sher, Muhammad

2017-01-01

The current research focused on improvement of oral bioavailability and decrease in dosing frequency of ivabradine (Iva) in order to enhance patient compliance by formulating novel sustained release Iva loaded solid lipid microparticles (SLMs) with the help of melt emulsification technique. SLMs formulations were designed with the help of three level central composite rotatable design (CCRD) to study the impact of independent variables like lipid concentration, surfactant concentration and stirring speed on responses - percentage yield (Y,) and entrapment efficiency (Y2). Compatibility between the drug and bees wax (BW) was checked by conducting Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRD). SLMs were further evaluated for rheological behavior, zeta potential, particle size and for morphology by scanning'electron microscope (SEM). The release of drug from SLMs was conducted by USP type-Il apparatus at pH 1.2, pH 6.8 and data were analyzed by different kinetic models like zero order, first order, Higuchi model, Korsmeyer-Peppas and Hixon-Crowell models. The rheo- logical studies approved the good flow behavior of SLMs and spherical smooth surface of SLMs was observed from SEM. DSC, FTIR and XRD studies concluded the lack of any possible interaction between formulation components. The size-of SLMs ranged from 300 to 500 pm and zeta potential study showed the presence of higher negative charge (-30 to -52 mV). Response Y, varied from 53 to 90% and response Y2 ranged from 29 to 78% indicating the effect of formulation variables. The obtained outcomes were analyzed by second order polynomial equation and suggested quadratic model was also validated. SLMs released Iva from 54 to 90% at pH 6.8 and was significantly (p 0.05) affected by BW concentration. The release mechanism followed the zero order and Korsmeyer-Peppas (n 0.85) kinetic models suggesting slow erosion along with diffusion

Fixation method does not affect restoration of rotation center in hip replacements: A single-site retrospective study

OpenAIRE

Wegner, Alexander; Kauther, Max Daniel; Landgraeber, Stefan; von Knoch, Marius

2012-01-01

Abstract Background Aseptic loosening is one of the greatest problems in hip replacement surgery. The rotation center of the hip is believed to influence the longevity of fixation. The aim of this study was to compare the influence of cemented and cementless cup fixation techniques on the position of the center of rotation because cemented cup fixation requires the removal of more bone for solid fixation than the cementless technique. Methods We retrospectively compared pre- and post-operativ...

Preliminary Study of Greywater Treatment through Rotating Biological Contactor

Directory of Open Access Journals (Sweden)

Ashfaq Ahmed Pathan

2011-07-01

Full Text Available The characteristics of the greywater vary from country to country and it depends upon the cultural and social behavior of the respective country. There was a considerable need to characterize and recycle the greywater. In this regard greywater was separated from the black water and analyzed for various physiochemical parameters. Among various greywater recycling treatment technologies, RBC (Rotating Biological Contactor is more effective treatment technique in reducing COD (Chemical Oxygen Demand and organic matters from the greywater. But this technology was not applied and tested in Pakistan. There was extensive need to investigate the RBC technology for greywater recycling at small scale before applying at mass scale. To treat the greywater, a single-stage RBC simulator was designed and developed at laboratory scale. An electric motor equipped with gear box to control the rotations of the disks was mounted on the tank. The simulator was run at the rate of 1.7 rpm. The disc area of the RBC was immersed about 40% in the greywater. Water samples were collected at each HRT (Hydraulic Retention Time and analyzed for the parameters such as pH, conductivity, TDS (Total Dissolved Solids, salinity, BOD5 (Biochemical Oxygen Demand, COD and suspended solids by using standard methods. The results are encouraging with percentage removal of BOD5 and COD being 53 and 60% respectively.

Development of the plastic solid-dye cell for tunable solid-state dye lasers and study on its optical properties

Energy Technology Data Exchange (ETDEWEB)

Ko, Do Kyeong; Lee, Jong Min; Cha, Byung Heon; Yi, Jong Hoon; Lee, Kang Soo; Kim, Sung Ho; Lim, Gwon

2000-01-01

We have fabricated solid-state dyes with Copolex NK-55, which is the base element of plastic lens, and PMMA. We have measured the longevity of solid-state dyes doped in both polymers and found that PMMA has better properties than Coploex NK-55. We have realized the tuning range of 560-620 nm by doping rhodamine 6Gand rhodamin B in the manufactured solid-state dye laser oscillators. In the standing-wave cavity we achieved the slop efficiency of 10.8 percent and in the grazing incidence cavity, 1.2 percent. We have constructed a very compact grazing- incidence cavity which is only 6 cm long and the linewidth of the laser was less than 1.5 GHz with 3-ns pulse duration. And we have fabricated disk-type solid-state dye cell and installed it in the cavity in which the dye cell can be translated and rotated with the help of the two steeping motors. By this we could constantly changed the illuminated area of the dye cell and , therefore, were able to achieve long time operation and to use almost the entire region of the solid-state dye cell. (author)

Development of the plastic solid-dye cell for tunable solid-state dye lasers and study on its optical properties

International Nuclear Information System (INIS)

Ko, Do Kyeong; Lee, Jong Min; Cha, Byung Heon; Yi, Jong Hoon; Lee, Kang Soo; Kim, Sung Ho; Lim, Gwon

2000-01-01

We have fabricated solid-state dyes with Copolex NK-55, which is the base element of plastic lens, and PMMA. We have measured the longevity of solid-state dyes doped in both polymers and found that PMMA has better properties than Coploex NK-55. We have realized the tuning range of 560-620 nm by doping rhodamine 6G and rhodamin B in the manufactured solid-state dye laser oscillators. In the standing-wave cavity we achieved the slop efficiency of 10.8 percent and in the grazing incidence cavity, 1.2 percent. We have constructed a very compact grazing- incidence cavity which is only 6 cm long and the linewidth of the laser was less than 1.5 GHz with 3-ns pulse duration. And we have fabricated disk-type solid-state dye cell and installed it in the cavity in which the dye cell can be translated and rotated with the help of the two steeping motors. By this we could constantly changed the illuminated area of the dye cell and , therefore, were able to achieve long time operation and to use almost the entire region of the solid-state dye cell. (author)

MR imaging of rotator cuff tears

International Nuclear Information System (INIS)

Kumagai, Hideo

1992-01-01

A total of 115 patients with clinical symptoms and signs suggesting rotator cuff tears underwent MR imaging with a 1.5-Tesla system. The body coil was used as the receiver coil in 24 patients and a single 10 cm surface coil in 91. Arthrography or MR imaging with intra-articular Gd-DTPA (MR arthrography) was performed in 95 of the 115. T2-weighted images with the body coil showed high signal intensity lesions in rotator cuffs in only seven of the 10 patients who had tears demonstrated by arthrography or MR arthrography. On the other hand, T2-weighted images with the surface coil demonstrated high signal intensity lesions in cuffs in all 27 patients who were diagnosed to have tears by arthrography or MR arthrography. In 12 patietns, T2-wighted images with the surface coil showed high signal intensity lesions in cuffs, while arthrography and MR arthrography did not show tears. Surgery was performed in four of the 12 patients and partial tears were confirmed. A single 10 cm surface coil, 3 mm slice thickness and 2.5 second repetition time seem to account for the fine visualization of cuff tears by the T2-weighted images. These results suggest that T2-weighted images obtained with the surface coil are superior to arthrography and MR arthrography. (author)

Shoulder Rotator Muscle Dynamometry Characteristics: Side Asymmetry and Correlations with Ball-Throwing Speed in Adolescent Handball Players

Science.gov (United States)

Pontaga, Inese; Zidens, Janis

2014-01-01

The aim of the investigation was to: 1) compare shoulder external/internal rotator muscles’ peak torques and average power values and their ratios in the dominant and non-dominant arm; 2) determine correlations between shoulder rotator muscles’ peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15-year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg). The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external– concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles. PMID:25414738

Shoulder Rotator Muscle Dynamometry Characteristics: Side Asymmetry and Correlations with Ball-Throwing Speed in Adolescent Handball Players

Directory of Open Access Journals (Sweden)

Pontaga Inese

2014-10-01

Full Text Available The aim of the investigation was to: 1 compare shoulder external/internal rotator muscles’ peak torques and average power values and their ratios in the dominant and non-dominant arm; 2 determine correlations between shoulder rotator muscles’ peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15- year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg. The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external- concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles

Isokinetic strength of shoulder internal and external rotators in cricket bowlers

Directory of Open Access Journals (Sweden)

X.M. Mabasa

2002-02-01

Full Text Available The strength of the shoulder internal and external rotators incricket bowlers, may not be sufficient to cope with the demands of bowling.As very little research has been done on cricketers, this study was done to establish the isokinetic strength profile of the shoulder internal andexternal rotators in cricket bowlers.Isokinetic, shoulder rotational strength was evaluated in thirty malecricket volunteers with a mean age of 23.9 years and mean body weight of 70.3 kgs. The Cybex 340 dynamometer multi joint system was used to collect data on shoulder rotation strength in a standing neutral position. Data were collected at four different speeds (60,90,180 and 300deg/sec and were computed for peak torque values for internal and external ratios for both dominant and non dominant shoulders.The results showed no statistically significant difference in the mean shoulder rotational torque between the bowlingand non-bowling shoulders for external rotation (p>0.05, and indicated statistically significant differences in themean shoulder rotational torque between the bowling and non-bowling shoulders for internal rotation (p<0.05. Therewas a significant decrease in isokinetic peak torque production for the external/internal rotator muscles as the speedof contraction increased (p<0.05. The peak torque ratio for the external/internal rotator muscles of the bowling armwere significantly less than of the non-bowling arm (p<0.05. These findings suggest that the strength ratios of thebowling arm need to be considered when managing young cricketers and their injuries.

Heisenberg Model in a Rotating Magnetic Field

Institute of Scientific and Technical Information of China (English)

LIN Qiong-Gui

2005-01-01

We study the Heisenberg model under the influence of a rotating magnetic field. By using a time-dependent unitary transformation, the time evolution operator for the Schrodinger equation is obtained, which involves no chronological product. The spin vectors (mean values of the spin operators) are obtained as explicit functions of time in the most general case. A series of cyclic solutions are presented. The nonadiabatic geometric phases of these cyclic solutions are calculated, and are expressed in terms of the solid angle subtended by the closed trace of the total spin vector, as well as in terms of those of the individual spins.

Introduction to solid mechanics an integrated approach

CERN Document Server

Lubliner, Jacob

2017-01-01

This expanded second edition presents in one text the concepts and processes covered in statics and mechanics of materials curricula following a systematic, topically integrated approach. Building on the novel pedagogy of fusing concepts covered in traditional undergraduate courses in rigid-body statics and deformable body mechanics, rather than simply grafting them together, this new edition develops further the authors’ very original treatment of solid mechanics with additional figures, an elaboration on selected solved problems, and additional text as well as a new subsection on viscoelasticity in response to students’ feedback. Introduction to Solid Mechanics: An Integrated Approach, Second Edition, offers a holistic treatment of the depth and breadth of solid mechanics and the inter-relationships of its underlying concepts. Proceeding from first principles to applications, the book stands as a whole greater than the sum of its parts.  .

Gastight Hydrodynamic Electrochemistry: Design for a Hermetically Sealed Rotating Disk Electrode Cell.

Science.gov (United States)

Jung, Suho; Kortlever, Ruud; Jones, Ryan J R; Lichterman, Michael F; Agapie, Theodor; McCrory, Charles C L; Peters, Jonas C

2017-01-03

Rotating disk electrodes (RDEs) are widely used in electrochemical characterization to analyze the mechanisms of various electrocatalytic reactions. RDE experiments often make use of or require collection and quantification of gaseous products. The combination of rotating parts and gaseous analytes makes the design of RDE cells that allow for headspace analysis challenging due to gas leaks at the interface of the cell body and the rotator. In this manuscript we describe a new, hermetically sealed electrochemical cell that allows for electrode rotation while simultaneously providing a gastight environment. Electrode rotation in this new cell design is controlled by magnetically coupling the working electrode to a rotating magnetic driver. Calibration of the RDE using a tachometer shows that the rotation speed of the electrode is the same as that of the magnetic driver. To validate the performance of this cell for hydrodynamic measurements, limiting currents from the reduction of a potassium ferrocyanide (K 4 [Fe(CN) 6 ]·3H 2 O) were measured and shown to compare favorably with calculated values from the Levich equation and with data obtained using more typical, nongastight RDE cells. Faradaic efficiencies of ∼95% were measured in the gas phase for oxygen evolution in alkaline media at an Inconel 625 alloy electrocatalyst during rotation at 1600 rpm. These data verify that a gastight environment is maintained even during rotation.

SU-E-J-195: Quantification of Rotations and Deformations in Head and Heck Radiotherapy

International Nuclear Information System (INIS)

Kim, J; Liu, C; Kumarasiri, A; Gordon, J; Siddiqui, F; Chetty, I J; Chetvertkov, M

2014-01-01

Purpose: To quantify the magnitude of patient rotations and deformations over the course of head and neck radiotherapy. Methods: 45 CBCT images acquired weekly were selected retrospectively from 5 head and neck cancer patients. CBCT images were registered to the corresponding planning CT images using translation, rigid-body, and cubic B-spline deformable transformations. Elastix ( elastix.isi.uu.nl ), an open-source public domain registration algorithm, was used for all registrations with mutual information as similarity metric and gradient descent as optimization. Four-level multiresolution approach was employed with 2 cm B-spline grid spacing at the finest resolution. Registration qualities were visually verified. Rotational occurrences were quantified from the rigid-body registrations. The magnitude of deformations in planning target volumes (PTV) and organs were quantified from the deformation vector fields with rigid registrations as baseline. Results: The measured rotations (mean±std) were 1.0±1.0 deg, - 0.3±1.0 deg, and 0.1±0.8 deg in the sagittal, coronal, and axial plains respectively. The estimated magnitudes of deformations (mean±std) were 3.4±2.1 mm for PTVs, 2.9±1.2 mm for parotid glands, 2.8±1.2 mm for mandible, and 2.2±1.1 mm for spinal cord. The overall deformation in the body contour was 4.3±4.3 mm. The organ spatial deviation due to rotation was small and approximately 8.4% of that from deformations. Results varied among patients. Conclusion: Rotations occurred about 1.0 deg (1SD) in the H'N area. Daily geometric deviation of target volumes was considerable and mainly from tissue deformation than rotations. Proper safety margin is necessary for adequate target coverage. Online plan adaptation may mitigate the daily differences between the plan and actual patient poses. Partially supported by a grant from Varian Medical Systems, Palo Alto, CA

SU-E-J-195: Quantification of Rotations and Deformations in Head and Heck Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Kim, J; Liu, C; Kumarasiri, A; Gordon, J; Siddiqui, F; Chetty, I J [Henry Ford Health System, Detroit, MI (United States); Chetvertkov, M [Wayne State University, Detroit, MI (United States)

2014-06-01

Purpose: To quantify the magnitude of patient rotations and deformations over the course of head and neck radiotherapy. Methods: 45 CBCT images acquired weekly were selected retrospectively from 5 head and neck cancer patients. CBCT images were registered to the corresponding planning CT images using translation, rigid-body, and cubic B-spline deformable transformations. Elastix ( elastix.isi.uu.nl ), an open-source public domain registration algorithm, was used for all registrations with mutual information as similarity metric and gradient descent as optimization. Four-level multiresolution approach was employed with 2 cm B-spline grid spacing at the finest resolution. Registration qualities were visually verified. Rotational occurrences were quantified from the rigid-body registrations. The magnitude of deformations in planning target volumes (PTV) and organs were quantified from the deformation vector fields with rigid registrations as baseline. Results: The measured rotations (mean±std) were 1.0±1.0 deg, - 0.3±1.0 deg, and 0.1±0.8 deg in the sagittal, coronal, and axial plains respectively. The estimated magnitudes of deformations (mean±std) were 3.4±2.1 mm for PTVs, 2.9±1.2 mm for parotid glands, 2.8±1.2 mm for mandible, and 2.2±1.1 mm for spinal cord. The overall deformation in the body contour was 4.3±4.3 mm. The organ spatial deviation due to rotation was small and approximately 8.4% of that from deformations. Results varied among patients. Conclusion: Rotations occurred about 1.0 deg (1SD) in the H'N area. Daily geometric deviation of target volumes was considerable and mainly from tissue deformation than rotations. Proper safety margin is necessary for adequate target coverage. Online plan adaptation may mitigate the daily differences between the plan and actual patient poses. Partially supported by a grant from Varian Medical Systems, Palo Alto, CA.

Stress transmission in planar disordered solid foams

International Nuclear Information System (INIS)

Blumenfeld, Raphael

2003-01-01

Stress transmission in planar open-cell cellular solids is analysed using a recent theory developed for marginally rigid granular assemblies. This is made possible by constructing a one-to-one mapping between the two systems. General trivalent networks are mapped onto assemblies of rough grains, while networks where Plateau rules are observed, are mapped onto assemblies of smooth grains. The constitutive part of the stress transmission equations couples the stress directly to the local rotational disorder of the cellular structure via a new fabric tensor. An intriguing consequence of the analysis is that the stress field can be determined in terms of the microstructure alone independent of stress-strain information. This redefines the problem of structure-property relationship in these materials and poses questions on the relations between this formalism and elasticity theory. The deviation of the stress transmission equations from those of conventional solids has been interpreted in the context of granular assemblies as a new state of solid matter and the relevance of this interpretation to the state of matter of cellular solids is discussed

Body surface posture evaluation: construction, validation and protocol of the SPGAP system (Posture evaluation rotating platform system).

Science.gov (United States)

Schwertner, Debora Soccal; Oliveira, Raul; Mazo, Giovana Zarpellon; Gioda, Fabiane Rosa; Kelber, Christian Roberto; Swarowsky, Alessandra

2016-05-04

Several posture evaluation devices have been used to detect deviations of the vertebral column. However it has been observed that the instruments present measurement errors related to the equipment, environment or measurement protocol. This study aimed to build, validate, analyze the reliability and describe a measurement protocol for the use of the Posture Evaluation Rotating Platform System (SPGAP, Brazilian abbreviation). The posture evaluation system comprises a Posture Evaluation Rotating Platform, video camera, calibration support and measurement software. Two pilot studies were carried out with 102 elderly individuals (average age 69 years old, SD = ±7.3) to establish a protocol for SPGAP, controlling the measurement errors related to the environment, equipment and the person under evaluation. Content validation was completed with input from judges with expertise in posture measurement. The variation coefficient method was used to validate the measurement by the instrument of an object with known dimensions. Finally, reliability was established using repeated measurements of the known object. Expert content judges gave the system excellent ratings for content validity (mean 9.4 out of 10; SD 1.13). The measurement of an object with known dimensions indicated excellent validity (all measurement errors reality. To verify the images of objects with known dimensions the values for the width and height were, respectively, CV 0.88 (width) and 2.33 (height), SD 0.22 (width) and 0.35 (height), minimum and maximum values 24.83-25.2 (width) and 14.56 - 15.75 (height). In the analysis of different images (similar) of an individual, greater discrepancies were observed in the values found. The cervical index, for example, presented minimum and maximum values of 15.38 and 37.5, a coefficient of variation of 0.29 and a standard deviation of 6.78. The SPGAP was shown to be a valid and reliable instrument for the quantitative analysis of body posture with applicability and

Optical Signature Analysis of Tumbling Rocket Bodies via Laboratory Measurements

Science.gov (United States)

Cowardin, H.; Lederer, S.; Liou, J.-C.; Ojakangas, G.; Mulrooney, M.

2012-09-01

The NASA Orbital Debris Program Office has acquired telescopic lightcurve data on massive intact objects, specifically spent rocket bodies (R/Bs), to ascertain tumble rates in support of the Active Debris Removal (ADR) studies to help remediate the LEO environment. Tumble rates are needed to plan and develop proximity and docking operations for potential future ADR operations. To better characterize and model optical data acquired from ground-based telescopes, the Optical Measurements Center (OMC) at NASA/JSC emulates illumination conditions in space using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. The OMC employs a 75-W Xenon arc lamp as a solar simulator, an SBIG CCD camera with standard Johnson/Bessel filters, and a robotic arm to simulate an object's position and rotation. The OMC does not attempt to replicate the rotation rates, but focuses on ascertaining how an object is rotating as seen from multiple phase angles. The two targets studied are scaled (1:48) SL-8 Cosmos 3M second stages. The first target is painted in the standard Russian government "gray" scheme and the second target is white/orange as used for commercial missions. This paper summarizes results of the two scaled rocket bodies, each observed in three independent rotation states: (a) spin-stabilized rotation (about the long axis), (b) end-over-end rotation, and (c) a 10 degree wobble about the center of mass. The first two cases represent simple spin about either primary axis. The third - what we call "wobble" - represents maximum principal axis rotation, with an inertia tensor that is offset from the symmetry axes. By comparing the resultant phase and orientation-dependent laboratory signatures with actual lightcurves derived from telescopic observations of orbiting R/Bs, we intend to assess the intrinsic R/B rotation states. In the simplest case, simulated R/B behavior coincides with principal axis spin states, while more complex R

Cylindrical concave body of composite fibrous material

International Nuclear Information System (INIS)

1979-01-01

The invention is concerned with a cylindrical concave body of compound fibrous material which is intended to be exposed to high rotation speeds around its own longitudinal axis. The concave body in question has at least one layer of fibrils that are interwoven and enclose an identical angle with the longitudinal axis of the concave body in both directions. The concave body in question also has at least a second layer of fibrils that run in the direction of the circumference and are fitted radially to the outside. The cylindrical concave body of the invention is particularly well suited for application as a rotor tube in a gas ultra-centrifuge

Analysis of an ideal amorphous solid

International Nuclear Information System (INIS)

To, L.T.; Stachurski, Z.H.

2004-01-01

Full text: In geometrical terms, amorphous solids are fundamentally different from crystalline solids in that they can not be constructed by the crystallographic method of translation of the basis along a lattice. Therefore, to study amorphous structures we must invoke concepts and use measures different to those used for ordered structures. Nevertheless, an ideal amorphous solid must share together with the ideal crystalline solid in the same definition of the term 'ideal'. In both cases it must be a perfect body, in which perfection is carried through in every detail to an unlimited (infinite) size without fault or defect. The latest results on this research will be presented. To qualify for a solid, rigid body, close packing of the spheres is required. For an ideal amorphous solids composed of hard spheres of identical size, we impose a stricter condition for the packing, namely, to be such that all spheres are in fixed positions (no loose spheres). To define the ideal solid, we must define what we mean by a perfect amorphous structure. Here, perfection is defined by, first the definition of imperfections, and next by the requirement of absence of imperfections of any kind. We envisage two types of defects: (i) geometrical, and (ii) statistical. Geometrical defects are: a sphere of different size, a loose sphere, and a vacancy. A statistical defect is defined with respect to two statistical functions: Ψ(N C ), and Φ(S β ). The former describes the probability of a given sphere having nc number of touching contacts, and the latter describes the disposition of the contacts on the surface of the sphere. Defects relating to the two functions will be described. The results for the functions, Ψ(N C ), and Φ(S β ), for the corresponding radial distribution function, and so called blocking number will be presented from simulations of an ideal amorphous solid

Monitoring conformational dynamics with solid-state R1ρ experiments

International Nuclear Information System (INIS)

Quinn, Caitlin M.; McDermott, Ann E.

2009-01-01

A new application of solid-state rotating frame (R 1ρ ) relaxation experiments to observe conformational dynamics is presented. Studies on a model compound, dimethyl sulfone (DMS), show that R 1ρ relaxation due to reorientation of a chemical shift anisotropy (CSA) tensor undergoing chemical exchange can be used to monitor slow-to-intermediate timescale conformational exchange processes. Control experiments used d 6 -DMS and alanine to confirm that the technique is monitoring reorientation of the CSA tensor rather than dipolar interactions or methyl group rotation. The application of this method to proteins could represent a new site-specific probe of conformational dynamics

The Influence of X-Factor (Trunk Rotation and Experience on the Quality of the Badminton Forehand Smash

Directory of Open Access Journals (Sweden)

Zhang Zhao

2016-12-01

Full Text Available No existing studies of badminton technique have used full-body biomechanical modeling based on three-dimensional (3D motion capture to quantify the kinematics of the sport. The purposes of the current study were to: 1 quantitatively describe kinematic characteristics of the forehand smash using a 15-segment, full-body biomechanical model, 2 examine and compare kinematic differences between novice and skilled players with a focus on trunk rotation (the X-factor, and 3 through this comparison, identify principal parameters that contributed to the quality of the skill. Together, these findings have the potential to assist coaches and players in the teaching and learning of the forehand smash. Twenty-four participants were divided into two groups (novice, n = 10 and skilled, n = 14. A 10-camera VICON MX40 motion capture system (200 frames/s was used to quantify full-body kinematics, racket movement and the flight of the shuttlecock. Results confirmed that skilled players utilized more trunk rotation than novices. In two ways, trunk rotation (the X-factor was shown to be vital for maximizing the release speed of the shuttlecock – an important measure of the quality of the forehand smash. First, more trunk rotation invoked greater lengthening in the pectoralis major (PM during the preparation phase of the stroke which helped generate an explosive muscle contraction. Second, larger range of motion (ROM induced by trunk rotation facilitated a whip-like (proximal to distal control sequence among the body segments responsible for increasing racket speed. These results suggest that training intended to increase the efficacy of this skill needs to focus on how the X-factor is incorporated into the kinematic chain of the arm and the racket.

P-shaped Coiled Stator Ultrasound Motor for Rotating Intravascular Surgery Device

Directory of Open Access Journals (Sweden)

Toshinobu ABE

2015-01-01

Full Text Available The primary focus of this paper is the development of an ultra-miniature ultrasound motor for use in the human blood vessel. Since the size of the drive source for rotating the atherectomy device and intravascular ultrasonography system are large currently in practical use, it is installed outside the body, and the rotational power for the atherectomy device and intravascular ultrasonography system are transmitted through the long tortuous blood vessel. Such systems suffer from the problem that the rotation becomes non-uniform, and the problem that the available time is limited. We have therefore developed a P-shaped coiled stator ultrasound motor as a miniature ultrasound motor for rotating the ultrasound sensor for use in blood vessels in order to solve these problems. In this paper, we describe measurement of the torque, revolution speed, output power, efficiency, and particle motion on acoustic waveguide of the P-shaped coiled stator ultrasound motor.

Uses of solid state analogies in elementary particle theory

International Nuclear Information System (INIS)

Anderson, P.W.

1976-01-01

The solid state background of some of the modern ideas of field theory is reviewed, and additional examples of model situations in solid state or many-body theory which may have relevance to fundamental theories of elementary particles are adduced

Sensing Movement: Microsensors for Body Motion Measurement

Directory of Open Access Journals (Sweden)

Hansong Zeng

2011-01-01

Full Text Available Recognition of body posture and motion is an important physiological function that can keep the body in balance. Man-made motion sensors have also been widely applied for a broad array of biomedical applications including diagnosis of balance disorders and evaluation of energy expenditure. This paper reviews the state-of-the-art sensing components utilized for body motion measurement. The anatomy and working principles of a natural body motion sensor, the human vestibular system, are first described. Various man-made inertial sensors are then elaborated based on their distinctive sensing mechanisms. In particular, both the conventional solid-state motion sensors and the emerging non solid-state motion sensors are depicted. With their lower cost and increased intelligence, man-made motion sensors are expected to play an increasingly important role in biomedical systems for basic research as well as clinical diagnostics.

Nuclear collective rotation in the SU3 model, 2

International Nuclear Information System (INIS)

Kinouchi, Shin-ichi; Kishimoto, Teruo; Kammuri, Tetsuo.

1989-05-01

The collective rotation of a nuclear system with the SU 3 Hamiltonian is described by the quantal dynamical nuclear field theory. An angular frequency in the Coriolis interaction of the driving Hamiltonian is replaced by a total angular momentum operator divided by the corresponding moment of inertia. We consider here the low spin states for a triaxial intrinsic configuration. The rotational effect is taken into account by using the effective quadrupole and angular momentum operators, whose expressions are different depending on whether they refer to the laboratory frame or the body-fixed one. Effective forms of the total Hamiltonian and the particle angular momentum are compared with the exact SU 3 energy and the rotor's angular momentum, respectively. In order to dissolve the disagreement for the effective operators, the perturbing interaction should be supplemented by a residual part of the quadrupole-quadrupole interaction, which restores the rotational invariance of the intrinsic Hamiltonian. (author)

Lattice Boltzmann simulation of viscoelastic flow past a confined free rotating cylinder

Science.gov (United States)

Xia, Yi; Zhang, Peijie; Lin, Jianzhong; Ku, Xiaoke; Nie, Deming

2018-05-01

To study the dynamics of rigid body immersed in viscoelastic fluid, an Oldroyd-B fluid flow past an eccentrically situated, free rotating cylinder in a two-dimensional (2D) channel is simulated by a novel lattice Boltzmann method. Two distribution functions are employed, one of which is aimed to solve Navier-Stokes equation and the other to the constitutive equation, respectively. The unified interpolation bounce-back scheme is adopted to treat the moving curved boundary of cylinder, and the novel Galilean invariant momentum exchange method is utilized to obtain the hydrodynamic force and torque exerted on the cylinder. Results show that the center-fixed cylinder rotates inversely in the direction where a cylinder immersed in Newtonian fluid do, which generates a centerline-oriented lift force according to Magnus effect. The cylinder’s eccentricity, flow inertia, fluid elasticity and viscosity would affect the rotation of cylinder in different ways. The cylinder rotates more rapidly when located farther away from the centerline, and slows down when it is too close to the wall. The rotation frequency decreases with increasing Reynolds number, and larger rotation frequency responds to larger Weissenberg number and smaller viscosity ratio, indicating that the fluid elasticity and low solvent viscosity accelerates the flow-induced rotation of cylinder.

Time-odd mean fields in covariant density functional theory: Rotating systems

International Nuclear Information System (INIS)

Afanasjev, A. V.; Abusara, H.

2010-01-01

Time-odd mean fields (nuclear magnetism) and their impact on physical observables in rotating nuclei are studied in the framework of covariant density functional theory (CDFT). It is shown that they have profound effect on the dynamic and kinematic moments of inertia. Particle number, configuration, and rotational frequency dependencies of their impact on the moments of inertia have been analyzed in a systematic way. Nuclear magnetism can also considerably modify the band crossing features such as crossing frequencies and the properties of the kinematic and dynamic moments of inertia in the band crossing region. The impact of time-odd mean fields on the moments of inertia in the regions away from band crossing only weakly depends on the relativistic mean-field parametrization, reflecting good localization of the properties of time-odd mean fields in CDFT. The moments of inertia of normal-deformed nuclei considerably deviate from the rigid-body value. On the contrary, superdeformed and hyperdeformed nuclei have the moments of inertia which are close to rigid-body value. The structure of the currents in rotating frame, their microscopic origin, and the relations to the moments of inertia have been systematically analyzed. The phenomenon of signature separation in odd-odd nuclei, induced by time-odd mean fields, has been analyzed in detail.

GAROS, an aeroelastic code for coupled fixed-rotating structures

Energy Technology Data Exchange (ETDEWEB)

Rees, M. [Aerodyn Energiestyseme GmbH, Rendsburg (Germany); Vollan, A. [Pilatus Flugzeugwerke, Stans (Switzerland)

1996-09-01

The GAROS (General Analysis of Rotating Structures) program system has been specially designed to calculate aeroelastic stability and dynamic response of horizontal axis wind energy converters. Nevertheless it is also suitable for the dynamic analysis of helicopter rotors and has been used in the analysis of car bodies taking account of rotating wheels. GAROS was developed over the last 17 years. In the following the mechanical and the aerodynamic model will be discussed in detail. A short overview of the solution methods for the equation of motion in time and frequency domain will ge given. After this one example for the FEM model of the rotor and tower will be discussed. (EG)

Low-temperature matrix effects on orientational motion of Methyl radical trapped in gas solids: Angular tunneling vs. libration

Science.gov (United States)

Dmitriev, Yurij A.; Zelenetckii, Ilia A.; Benetis, Nikolas P.

2018-05-01

EPR investigation of the lineshape of matrix -isolated methyl radical, CH3, spectra recorded in solid N2O and CO2 was carried out. Reversible temperature-dependent line width anisotropy was observed in both matrices. This effect is a fingerprint of the extra-slow radical rotation about the in-plane C2 axes. The rotation was found to be anisotropic and closely correlated to the orientational dynamics of the matrix molecules. It was suggested that a recently discovered "hoping precession" effect of matrix molecules in solid CO2 is a common feature of matrices of the linear molecules CO, N2O, and CO2. A new low-temperature matrix effect, referred to as "libration trap", was proposed which accounts for the changing CH3 reorientational motion about the radical C3-axis from rotation to libration. Temperature dependence of the intensity of the EPR satellites produced by these nonrotating-but librating methyls was presented. This allowed for a rough estimation of the rotation hindering potential due to correlation mismatch between the radical and the nearest matrix molecules' librations.

Accumulation of Inertial Sensory Information in the Perception of Whole Body Yaw Rotation.

Science.gov (United States)

Nesti, Alessandro; de Winkel, Ksander; Bülthoff, Heinrich H

2017-01-01

While moving through the environment, our central nervous system accumulates sensory information over time to provide an estimate of our self-motion, allowing for completing crucial tasks such as maintaining balance. However, little is known on how the duration of the motion stimuli influences our performances in a self-motion discrimination task. Here we study the human ability to discriminate intensities of sinusoidal (0.5 Hz) self-rotations around the vertical axis (yaw) for four different stimulus durations (1, 2, 3 and 5 s) in darkness. In a typical trial, participants experienced two consecutive rotations of equal duration and different peak amplitude, and reported the one perceived as stronger. For each stimulus duration, we determined the smallest detectable change in stimulus intensity (differential threshold) for a reference velocity of 15 deg/s. Results indicate that differential thresholds decrease with stimulus duration and asymptotically converge to a constant, positive value. This suggests that the central nervous system accumulates sensory information on self-motion over time, resulting in improved discrimination performances. Observed trends in differential thresholds are consistent with predictions based on a drift diffusion model with leaky integration of sensory evidence.

Development of Swimming Human Simulation Model Considering Rigid Body Dynamics and Unsteady Fluid Force for Whole Body

Science.gov (United States)

Nakashima, Motomu; Satou, Ken; Miura, Yasufumi

The purpose of this study is to develop a swimming human simulation model considering rigid body dynamics and unsteady fluid force for the whole body, which will be utilized to analyze various dynamical problems in human swimming. First, the modeling methods and their formulations for the human body and the fluid force are respectively described. Second, experiments to identify the coefficients of the normal drag and the added mass are conducted by use of an experimental setup, in which a limb model rotates in the water, and its rotating angle and the bending moment at the root are measured. As the result of the identification, the present model for the fluid force was found to have satisfactory performance in order to represent the unsteady fluctuations of the experimental data, although it has 10% error. Third, a simulation for the gliding position is conducted in order to identify the tangential drag coefficient. Finally, a simulation example of standard six beat front crawl swimming is shown. The swimming speed of the simulation became a reasonable value, indicating the validity of the present simulation model, although it is 7.5% lower than the actual swimming.

Nanoparticles in dilute solution : A numerical study of rotational diffusion

Energy Technology Data Exchange (ETDEWEB)

Evensen, Tom Richard

2008-06-15

This thesis is dedicated to Brownian dynamics simulations of rotational diffusion. A rotation dynamics engine has been implemented and tested. This engine will in the future be integrated as a part of a complete Brownian dynamics simulation tool. The special case, when translational motion can be ignored, has thoroughly been studied. Two choices of generalized coordinates describing angular orientation of the particles are used. The Euler angles, which constitute the classical choice, and the Cartesian components of the rotation vector, which was recently introduced as an alternative, are being compared with regards to computational efficiency. Results from both equilibrium and non-equilibrium simulations are presented. The consistency of two new algorithms is demonstrated on systems of free rigid particles with arbitrary surface topographies. The algorithms make use of only the principal values of the rotational mobility tensor, assuming the corresponding principal axes coincide with the body-fixed coordinate system. These three scalars contain all information about the particle surface topography relevant for rotational diffusion. The calculation of the mobility tensor can be performed in a pre-calculation step, which makes the algorithm itself highly efficient. Both choices of generalized coordinates correctly reproduce theoretical predictions, but we have found that the algorithm using the Cartesian components of the rotation vector as generalized coordinates outperform its counterpart using the Euler angles by up to a factor 1000 in extreme cases. The reason for this improvement is that the algorithm using the Cartesian components of the rotation vector is free of singularities. (Author). refs. figs

Setup accuracy of stereoscopic X-ray positioning with automated correction for rotational errors in patients treated with conformal arc radiotherapy for prostate cancer

International Nuclear Information System (INIS)

Soete, Guy; Verellen, Dirk; Tournel, Koen; Storme, Guy

2006-01-01

We evaluated setup accuracy of NovalisBody stereoscopic X-ray positioning with automated correction for rotational errors with the Robotics Tilt Module in patients treated with conformal arc radiotherapy for prostate cancer. The correction of rotational errors was shown to reduce random and systematic errors in all directions. (NovalisBody TM and Robotics Tilt Module TM are products of BrainLAB A.G., Heimstetten, Germany)

An unsteady point vortex method for coupled fluid-solid problems

Energy Technology Data Exchange (ETDEWEB)

Michelin, Sebastien [Jacobs School of Engineering, UCSD, Department of Mechanical and Aerospace Engineering, La Jolla, CA (United States); Ecole Nationale Superieure des Mines de Paris, Paris (France); Llewellyn Smith, Stefan G. [Jacobs School of Engineering, UCSD, Department of Mechanical and Aerospace Engineering, La Jolla, CA (United States)

2009-06-15

A method is proposed for the study of the two-dimensional coupled motion of a general sharp-edged solid body and a surrounding inviscid flow. The formation of vorticity at the body's edges is accounted for by the shedding at each corner of point vortices whose intensity is adjusted at each time step to satisfy the regularity condition on the flow at the generating corner. The irreversible nature of vortex shedding is included in the model by requiring the vortices' intensity to vary monotonically in time. A conservation of linear momentum argument is provided for the equation of motion of these point vortices (Brown-Michael equation). The forces and torques applied on the solid body are computed as explicit functions of the solid body velocity and the vortices' position and intensity, thereby providing an explicit formulation of the vortex-solid coupled problem as a set of non-linear ordinary differential equations. The example of a falling card in a fluid initially at rest is then studied using this method. The stability of broadside-on fall is analysed and the shedding of vorticity from both plate edges is shown to destabilize this position, consistent with experimental studies and numerical simulations of this problem. The reduced-order representation of the fluid motion in terms of point vortices is used to understand the physical origin of this destabilization. (orig.)

Design of rotating mirror for ultra-high speed camera based on dynamic characteristic

International Nuclear Information System (INIS)

Li Chunbo; Chai Jinlong; Liang Yexing; Liu Chunping; Wang Hongzhi; Yu Chunhui; Li Jingzhen; Huang Hongbin

2011-01-01

A systematic design method has been proposed for studying the dynamic design of rotating mirror for ultra-high speed camera. With the finite element software, the numerical analyses of static, modal, harmonic responses and natural frequency sensitivity for the preliminary-designed rotating mirror were done based on the static and dynamic theories. Some experiments were done to verify the results. The physical dimensions of the rotating mirror were modified repeatedly according to the results for designing a new rotating mirror. Then simulation and experiments of fatigue life for the new rotating mirror under alternating force were done. The results show that the maximum static stress is less than the yield stress of the rotating mirror material, which proves the new rotating mirror will not be subjected to static strength failure. However, the results of modal and harmonic response analyses indicate that the dynamic characteristic of the new rotating mirror can not meet the design requirement for the first critical speed is less than the service speed. In all the physical dimensions of the rotating mirror, the circum radius of mirror body and natural frequency are negatively correlated and the degree of correlation is maximal. The first-order natural frequency in- creases from 459.4 Hz to 713.6 Hz, the rate of change is 55.3%, the first critical speed is up to 42 816 r/min, avoiding resonance successfully, and the fatigue strength of the new rotating mirror can meet the design requirement. (authors)

On Averaging Rotations

DEFF Research Database (Denmark)

Gramkow, Claus

1999-01-01

In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belo...... approximations to the Riemannian metric, and that the subsequent corrections are inherient in the least squares estimation. Keywords: averaging rotations, Riemannian metric, matrix, quaternion......In this article two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very offten the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

13C solid state NMR investigation of natural resins components

International Nuclear Information System (INIS)

Tavares, Maria I.B.; Bathista, Andre L.B.S.; Silva, Emerson O.; Priante Filho, Nicolau; Nogueira, Jose S.

2001-01-01

The objective of this work is to establish and analytical methodology as a routine using solid state nuclear magnetic resonance (NMR) techniques to investigate the mainly chemical components presented in natural resins in bulk. And also to evaluate the molecular behaviour of these resins. The routine solid state techniques allow us to assign the main compounds presented in the resins. Therefore, applying specialised techniques, like variable contact time, delayed contact time, dephasing time and proton spin lattice relaxation time in the rotating frame (T 1 H ρ), more information about chemical structure and molecular dynamic is available

Near-Wall Turbulence Modelling of Rotating and Curved Shear Flows

Energy Technology Data Exchange (ETDEWEB)

Pettersson, Bjoern Anders

1997-12-31

This thesis deals with verification and refinement of turbulence models within the framework of the Reynolds-averaged approach. It pays special attention to modelling the near-wall region, where the turbulence is strongly non-homogeneous and anisotropic. It also studies in detail the effects associated with an imposed rotation of the reference frame or streamline curvature. The objective with near-wall turbulence closure modelling is to formulate a set of equations governing single point turbulence statistics, which can be solved in the region of the flow which extends to the wall. This is in contrast to the commonly adopted wall-function approach in which the wall-boundary conditions are replaced by matching conditions in the logarithmic region. The near-wall models allow more flexibility by not requiring any such universal behaviour. Assessment of the novel elliptic relaxation approach to model the proximity of a solid boundary reveals an encouraging potential used in conjunction with second-moment and eddy-viscosity closures. The most natural level of closure modelling to predict flows affected by streamline curvatures or an imposed rotation of the reference frame is at the second-moment closure (SMC) level. Although SMCs naturally accounts for the effects of system rotation, the usual application of a scalar dissipation rate equation is shown to require ad hoc corrections in some cases in order to give good results. The elliptic relaxation approach is also used in conjunction with non-linear pressure-strain models and very encouraging results are obtained for rotating flows. Rotational induced secondary motions are vital to predicting the effects of system rotation. Some severe weaknesses of non-linear pressure-strain models are also indicated. Finally, a modelling methodology for anisotropic dissipation in nearly homogeneous turbulence are proposed. 84 refs., 56 figs., 16 tabs.

EVOLUTION OF ROTATIONAL VELOCITIES OF A-TYPE STARS

International Nuclear Information System (INIS)

Yang Wuming; Bi Shaolan; Tian Zhijia; Meng Xiangcun

2013-01-01

The equatorial velocity of A-type stars undergoes an acceleration in the first third of the main sequence (MS) stage, but the velocity decreases as if the stars were not undergoing any redistribution of angular momentum in the external layers in the last stage of the MS phase. Our calculations show that the acceleration and the decrease of the equatorial velocity can be reproduced by the evolution of the differential rotation zero-age MS model with the angular momentum transport caused by hydrodynamic instabilities during the MS stage. The acceleration results from the fact that the angular momentum stored in the interiors of the stars is transported outward. In the last stage, the core and the radiative envelope are uncoupling, and the rotation of the envelope is a quasi-solid rotation; the uncoupling and the expansion of the envelope indicate that the decrease of the equatorial velocity approximately follows the slope for the change in the equatorial velocity of the model without any redistribution of angular momentum. When the fractional age 0.3 ∼ MS ∼< 0.5, the equatorial velocity remains almost constant for stars whose central density increases with age in the early stage of the MS phase, while the velocity decreases with age for stars whose central density decreases with age in the early stage of the MS phase.

Translational and rotational intra- and inter-fractional errors in patient and target position during a short course of frameless stereotactic body radiotherapy

International Nuclear Information System (INIS)

Josipovic, Mirjana; Fredberg Persson, Gitte; Logadottir, Aashildur; Smulders, Bob; Westmann, Gunnar; Bangsgaard, Jens Peter

2012-01-01

Background. Implementation of cone beam computed tomography (CBCT) in frameless stereotactic body radiotherapy (SBRT) of lung tumours enables setup correction based on tumour position. The aim of this study was to compare setup accuracy with daily soft tissue matching to bony anatomy matching and evaluate intra- and inter-fractional translational and rotational errors in patient and target positions. Material and methods. Fifteen consecutive SBRT patients were included in the study. Vacuum cushions were used for immobilisation. SBRT plans were based on midventilation phase of four-dimensional (4D)-CT or three-dimensional (3D)-CT from PET/CT. Margins of 5 mm in the transversal plane and 10 mm in the cranio-caudal (CC) direction were applied. SBRT was delivered in three fractions within a week. At each fraction, CBCT was performed before and after the treatment. Setup accuracy comparison between soft tissue matching and bony anatomy matching was evaluated on pretreatment CBCTs. From differences in pre- and post-treatment CBCTs, we evaluated the extent of translational and rotational intra-fractional changes in patient position, tumour position and tumour baseline shift. All image registration was rigid with six degrees of freedom. Results. The median 3D difference between patient position based on bony anatomy matching and soft tissue matching was 3.0 mm (0-8.3 mm). The median 3D intra-fractional change in patient position was 1.4 mm (0-12.2 mm) and 2.2 mm (0-13.2 mm) in tumour position. The median 3D intra-fractional baseline shift was 2.2 mm (0-4.7 mm). With correction of translational errors, the remaining systematic and random errors were approximately 1deg. Conclusion. Soft tissue tumour matching improved precision of treatment delivery in frameless SBRT of lung tumours compared to image guidance using bone matching. The intra-fractional displacement of the target position was affected by both translational and rotational changes in tumour baseline position

Rotational acceleration during head impact resulting from different judo throwing techniques.

Science.gov (United States)

Murayama, Haruo; Hitosugi, Masahito; Motozawa, Yasuki; Ogino, Masahiro; Koyama, Katsuhiro

2014-01-01

Most severe head injuries in judo are reported as acute subdural hematoma. It is thus necessary to examine the rotational acceleration of the head to clarify the mechanism of head injuries. We determined the rotational acceleration of the head when the subject is thrown by judo techniques. One Japanese male judo expert threw an anthropomorphic test device using two throwing techniques, Osoto-gari and Ouchi-gari. Rotational and translational head accelerations were measured with and without an under-mat. For Osoto-gari, peak resultant rotational acceleration ranged from 4,284.2 rad/s(2) to 5,525.9 rad/s(2) and peak resultant translational acceleration ranged from 64.3 g to 87.2 g; for Ouchi-gari, the accelerations respectively ranged from 1,708.0 rad/s(2) to 2,104.1 rad/s(2) and from 120.2 g to 149.4 g. The resultant rotational acceleration did not decrease with installation of an under-mat for both Ouchi-gari and Osoto-gari. We found that head contact with the tatami could result in the peak values of translational and rotational accelerations, respectively. In general, because kinematics of the body strongly affects translational and rotational accelerations of the head, both accelerations should be measured to analyze the underlying mechanism of head injury. As a primary preventative measure, throwing techniques should be restricted to participants demonstrating ability in ukemi techniques to avoid head contact with the tatami.

Gravitomagnetic field of the universe and Coriolis force on the rotating Earth

International Nuclear Information System (INIS)

Veto, B

2011-01-01

The Machian effect of distant masses of the universe in the frame of reference of the rotating Earth is demonstrated using the gravitomagnetic approach of general relativity. This effect appears in the form of a gravitomagnetic Lorentz force acting on moving bodies on the Earth. The gravitomagnetic field of the universe-deduced from a simple model-exerts a gravitomagnetic Lorentz force on moving bodies, a force parallel to and with comparable strength to the Coriolis force observed on the rotating Earth. It seems after simple considerations that the Coriolis force happens to be the gravitomagnetic Lorentz force exerted by the mass of a black hole universe. The description of the phenomenon is simpler using the gravitomagnetic approach than the standard formulation of general relativity, so the method relying on gravitomagnetism is advisable in lectures intended for master's degree level physics students and advanced undergraduates.

Simulation of the infiltration process of a ceramic open-pore body with a metal alloy in semi-solid state to design the manufacturing of interpenetrating phase composites

Science.gov (United States)

Schomer, Laura; Liewald, Mathias; Riedmüller, Kim Rouven

2018-05-01

Metal-ceramic Interpenetrating Phase Composites (IPC) belong to a special subcategory of composite materials and reveal enhanced properties compared to conventional composite materials. Currently, IPC are produced by infiltration of a ceramic open-pore body with liquid metal applying high pressure and I or high temperature to avoid residual porosity. However, these IPC are not able to gain their complete potential, because of structural damages and interface reactions occurring during the manufacturing process. Compared to this, the manufacturing of IPC using the semi-solid forming technology offers great perspectives due to relative low processing temperatures and reduced mechanical pressure. In this context, this paper is focusing on numerical investigations conducted by using the FLOW-3D software for gaining a deeper understanding of the infiltration of open-pore bodies with semi-solid materials. For flow simulation analysis, a geometric model and different porous media drag models have been used. They have been adjusted and compared to get a precise description of the infiltration process. Based on these fundamental numerical investigations, this paper also shows numerical investigations that were used for basically designing a semi-solid forming tool. Thereby, the development of the flow front and the pressure during the infiltration represent the basis of the evaluation. The use of an open and closed tool cavity combined with various geometries of the upper die shows different results relating to these evaluation arguments. Furthermore, different overflows were designed and its effects on the pressure at the end of the infiltration process were investigated. Thus, this paper provides a general guideline for a tool design for manufacturing of metal-ceramic IPC using semi-solid forming.

Solid-Liquid equilibrium of n-alkanes using the Chain Delta Lattice Parameter model

DEFF Research Database (Denmark)

Coutinho, João A.P.; Andersen, Simon Ivar; Stenby, Erling Halfdan

1996-01-01

The formation of a solid phase in liquid mixtures with large paraffinic molecules is a phenomenon of interest in the petroleum, pharmaceutical, and biotechnological industries among onters. Efforts to model the solid-liquid equilibrium in these systems have been mainly empirical and with different...... degrees of success.An attempt to describe the equilibrium between the high temperature form of a paraffinic solid solution, commonly known as rotator phase, and the liquid phase is performed. The Chain Delta Lattice Parameter model (CDLP) is developed allowing a successful description of the solid-liquid...... equilibrium of n-alkanes ranging from n-C_20 to n-C_40.The model is further modified to achieve a more correct temperature dependence because it severely underestimates the excess enthalpy. It is shown that the ratio of excess enthalpy and entropy for n-alkane solid solutions, as happens for other solid...

The Taylor-Proudman column in a rapidly-rotating compressible fluid I. energy transports

International Nuclear Information System (INIS)

Park, Jun Sang

2014-01-01

A theoretical study is made of the steady flow of a compressible fluid in a rapidly rotating finite cylinder. Flow is generated by imposing mechanical and/or thermal disturbances at the rotating endwall disks. Both the Ekman and Rossby numbers are small. An examination is made of the energy budget for a control volume in the Ekman boundary layer. A combination of physical variables, which is termed the energy flux content, consisting of temperature and modified angular momentum, emerges to be relevant. The distinguishing features of a compressible fluid, in contrast to those of an incompressible fluid, are noted. A plausible argument is given to explain the difficulty in achieving the Taylor-Proudman column in a compressible rotating fluid. For the Taylor-Proudman column to be sustained, in the interior, it is shown that the net energy transport between the solid disk wall and the interior fluid should vanish. Physical rationalizations are facilitated by resorting to the concept of the afore-stated energy flux content.

Fortnightly Earth Rotation, Ocean Tides, and Mantle Anelasticity

Science.gov (United States)

Ray, Richard D.; Egbert, Gary D.

2011-01-01

Sustained accurate measurements of earth rotation are one of the prime goals of Global Geodetic Observing System (GGOS). We here concentrate on the fortnightly (Mf) tidal component of earth-rotation data to obtain new results concerning anelasticity of the mantle at this period. The study comprises three parts: (1) a new determination of the Mf component of polar motion and length-of-day from a multi-decade time series of space-geodetic data; (2) the use of the polar-motion determination as one constraint in the development of a hydrodynamic ocean model of the Mf tide; and (3) the use of these results to place new constraints on mantle anelasticity. Our model of the Mf ocean tide assimilates more than fourteen years of altimeter data from the Topex/Poseidon and Jason-1 satellites. The polar motion data, plus tide-gauge data and independent altimeter data, give useful additional information, with only the polar motion putting constraints on tidal current velocities. The resulting ocean-tide model, plus the dominant elastic body tide, leaves a small residual in observed length-of-day caused by mantle anelasticity. The inferred effective tidal 0 of the anelastic body tide is 90 and is in line with a omega-alpha frequency dependence with alpha in the range 0.2--0.3.

Study of a Microfluidic Chip Integrating Single Cell Trap and 3D Stable Rotation Manipulation

Directory of Open Access Journals (Sweden)

Liang Huang

2016-08-01

Full Text Available Single cell manipulation technology has been widely applied in biological fields, such as cell injection/enucleation, cell physiological measurement, and cell imaging. Recently, a biochip platform with a novel configuration of electrodes for cell 3D rotation has been successfully developed by generating rotating electric fields. However, the rotation platform still has two major shortcomings that need to be improved. The primary problem is that there is no on-chip module to facilitate the placement of a single cell into the rotation chamber, which causes very low efficiency in experiment to manually pipette single 10-micron-scale cells into rotation position. Secondly, the cell in the chamber may suffer from unstable rotation, which includes gravity-induced sinking down to the chamber bottom or electric-force-induced on-plane movement. To solve the two problems, in this paper we propose a new microfluidic chip with manipulation capabilities of single cell trap and single cell 3D stable rotation, both on one chip. The new microfluidic chip consists of two parts. The top capture part is based on the least flow resistance principle and is used to capture a single cell and to transport it to the rotation chamber. The bottom rotation part is based on dielectrophoresis (DEP and is used to 3D rotate the single cell in the rotation chamber with enhanced stability. The two parts are aligned and bonded together to form closed channels for microfluidic handling. Using COMSOL simulation and preliminary experiments, we have verified, in principle, the concept of on-chip single cell traps and 3D stable rotation, and identified key parameters for chip structures, microfluidic handling, and electrode configurations. The work has laid a solid foundation for on-going chip fabrication and experiment validation.

Vibrot, a simple device for the conversion of vibration into rotation mediated by friction: preliminary evaluation.

Directory of Open Access Journals (Sweden)

Ernesto Altshuler

Full Text Available While "vibrational noise" induced by rotating components of machinery is a common problem constantly faced by engineers, the controlled conversion of translational into rotational motion or vice-versa is a desirable goal in many scenarios ranging from internal combustion engines to ultrasonic motors. In this work, we describe the underlying physics after isolating a single degree of freedom, focusing on devices that convert a vibration along the vertical axis into a rotation around this axis. A typical Vibrot (as we label these devices consists of a rigid body with three or more cantilevered elastic legs attached to its bottom at an angle. We show that these legs are capable of transforming vibration into rotation by a "ratchet effect", which is caused by the anisotropic stick-slip-flight motion of the leg tips against the ground. Drawing an analogy with the Froude number used to classify the locomotion dynamics of legged animals, we discuss the walking regime of these robots. We are able to control the rotation frequency of the Vibrot by manipulating the shaking amplitude, frequency or waveform. Furthermore, we have been able to excite Vibrots with acoustic waves, which allows speculating about the possibility of reducing the size of the devices so they can perform tasks into the human body, excited by ultrasound waves from the outside.

Scaling of rotation and isotope separation in a vacuum-arc centrifuge

International Nuclear Information System (INIS)

Prasad, R.R.; Krishnan, M.

1987-01-01

Scaling is described of rotation, plasma column size and separation in a vacuum-arc centrifuge. The vacuum-arc centrifuge is a magnetized, fulled ionized, quasineutral column of plasma. The source of plasma is a vacuum-arc discharge between a negatively biased cathode and a grounded mesh anode. Rigid-body rotation, induced by the J x B force, causes radial, centrifugal separation of isotopes in the plasma column. Salient features of a fluid model that provides an understanding of rotation and the concomitant isotope separation in the vacuum-arc centrifuge are described. Scaling of rotation and plasma column size is found be consistent with the model. Measurements of isotope separation, also found to agree with the predictions of the model, are presented. Results of a parametric analysis of isotope separation in such a vacuum-arc centrifuge, using the fluid model and the observed scaling laws, are described. An analysis of the energy cost of separation of the vacuum-arc centrifuge shows that it typically requires only 70 keV/separated atom. (orig.)

Falling, flapping, flying, swimming,...: High-Re fluid-solid interactions with vortex shedding

Science.gov (United States)

Michelin, Sebastien Honore Roland

The coupling between the motion of a solid body and the dynamics of the surrounding flow is essential to the understanding of a large number of engineering and physical problems, from the stability of a slender structure exposed to the wind to the locomotion of insects, birds and fishes. Because of the strong coupling on a moving boundary of the equations for the solid and fluid, the simulation of such problems is computationally challenging and expensive. This justifies the development of simplified models for the fluid-solid interactions to study their physical properties and behavior. This dissertation proposes a reduced-order model for the interaction of a sharp-edged solid body with a strongly unsteady high Reynolds number flow. In such a case, viscous forces in the fluid are often negligible compared to the fluid inertia or the pressure forces, and the thin boundary layers separate from the solid at the edges, leading to the shedding of large and persistent vortices in the solid's wake. A general two-dimensional framework is presented based on complex potential flow theory. The formation of the solid's vortical wake is accounted for by the shedding of point vortices with unsteady intensity from the solid's sharp edges, and the fluid-solid problem is reformulated exclusively as a solid-vortex interaction problem. In the case of a rigid solid body, the coupled problem is shown to reduce to a set of non-linear ordinary differential equations. This model is used to study the effect of vortex shedding on the stability of falling objects. The solid-vortex model is then generalized to study the fluttering instability and non-linear flapping dynamics of flexible plates or flags. The uttering instability and resulting flapping motion result from the competing effects of the fluid forcing and of the solid's flexural rigidity and inertia. Finally, the solid-vortex model is applied to the study of the fundamental effect of bending rigidity on the flapping performance of

Pelvic rotation torque during fast-pitch softball hitting under three ball height conditions.

Science.gov (United States)

Iino, Yoichi; Fukushima, Atsushi; Kojima, Takeji

2014-08-01

The purpose of this study was to investigate the relevance of hip joint angles to the production of the pelvic rotation torque in fast-pitch softball hitting and to examine the effect of ball height on this production. Thirteen advanced female softball players hit stationary balls at three different heights: high, middle, and low. The pelvic rotation torque, defined as the torque acting on the pelvis through the hip joints about the pelvic superior-inferior axis, was determined from the kinematic and force plate data using inverse dynamics. Irrespective of the ball heights, the rear hip extension, rear hip external rotation, front hip adduction, and front hip flexion torques contributed to the production of pelvic rotation torque. Although the contributions of the adduction and external rotation torques at each hip joint were significantly different among the ball heights, the contributions of the front and rear hip joint torques were similar among the three ball heights owing to cancelation of the two torque components. The timings of the peaks of the hip joint torque components were significantly different, suggesting that softball hitters may need to adjust the timings of the torque exertions fairly precisely to rotate the upper body effectively.

Geometrical setting of solid mechanics

International Nuclear Information System (INIS)

Fiala, Zdenek

2011-01-01

Highlights: → Solid mechanics within the Riemannian symmetric manifold GL (3, R)/O (3, R). → Generalized logarithmic strain. → Consistent linearization. → Incremental principle of virtual power. → Time-discrete approximation. - Abstract: The starting point in the geometrical setting of solid mechanics is to represent deformation process of a solid body as a trajectory in a convenient space with Riemannian geometry, and then to use the corresponding tools for its analysis. Based on virtual power of internal stresses, we show that such a configuration space is the (globally) symmetric space of symmetric positive-definite real matrices. From this unifying point of view, we shall analyse the logarithmic strain, the stress rate, as well as linearization and intrinsic integration of corresponding evolution equation.

Nonlinear elastic inclusions in isotropic solids

KAUST Repository

Yavari, A.

2013-10-16

We introduce a geometric framework to calculate the residual stress fields and deformations of nonlinear solids with inclusions and eigenstrains. Inclusions are regions in a body with different reference configurations from the body itself and can be described by distributed eigenstrains. Geometrically, the eigenstrains define a Riemannian 3-manifold in which the body is stress-free by construction. The problem of residual stress calculation is then reduced to finding a mapping from the Riemannian material manifold to the ambient Euclidean space. Using this construction, we find the residual stress fields of three model systems with spherical and cylindrical symmetries in both incompressible and compressible isotropic elastic solids. In particular, we consider a finite spherical ball with a spherical inclusion with uniform pure dilatational eigenstrain and we show that the stress in the inclusion is uniform and hydrostatic. We also show how singularities in the stress distribution emerge as a consequence of a mismatch between radial and circumferential eigenstrains at the centre of a sphere or the axis of a cylinder.

Asteroid rotation rates

International Nuclear Information System (INIS)

Binzel, R.P.; Farinella, P.

1989-01-01

Within the last decade the data base of asteroid rotation parameters (rotation rates and lightcurve amplitudes) has become sufficiently large to identify some definite rends and properties which can help us to interpret asteroid collisional evolution. Many significant correlations are found between rotation parameters and diameter, with distinct changes occurring near 125 km. The size range, which is also the diameter above which self-gravity may become important, perhaps represents a division between surviving primordial asteroids and collisional fragments. A Maxwellian is able to fit the observed rotation rate distributions of asteroids with D>125 km, implying that their rotation rates may be determined by collisional evolution. Asteroids with D<125 km show an excess of slow rotators and their non-Maxwellian distributions suggests that their rotation rates are more strongly influenced by other processes, such as the distribution resulting from their formation in catastrophic disruption events. Other correlations observed in the data set include different mean rotation rates for C, S and M type asteroids implying that their surface spectra are indicative of bulk properties

Metode Penurunan Respon Dinamik Sistem Poros-rotor dengan Peredam Viscous Rotary

OpenAIRE

Nusyirwan, Nusyirwan

2014-01-01

Viscosity or viscosity is one of the quantities that are very important in the analysis of the behavior and movement of fluids that come into contact with other objects such as solids {solid body). Viscous dampers can be used to reduce the amplitude of the response due to the unbalanced mass, rotation critically, noise and shock loads. Absorbers working with fluid film bearing securities which are placed at a certain point, which is connected to the shaft-rotating rotor. Certain viscosity flu...

On Averaging Rotations

DEFF Research Database (Denmark)

Gramkow, Claus

2001-01-01

In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong ...... approximations to the Riemannian metric, and that the subsequent corrections are inherent in the least squares estimation.......In this paper two common approaches to averaging rotations are compared to a more advanced approach based on a Riemannian metric. Very often the barycenter of the quaternions or matrices that represent the rotations are used as an estimate of the mean. These methods neglect that rotations belong...

The effects of the solid inner core and nonhydrostatic structure on the earth's forced nutations and earth tides

Science.gov (United States)

De Vries, Dan; Wahr, John M.

1991-01-01

This paper computes the effects of the solid inner core (IC) on the forced nutations and earth tides, and on certain of the earth's rotational normal modes. The theoretical results are extended to include the effects of a solid IC and of nonhydrostatic structure. The presence of the IC is responsible for a new, almost diurnal, prograde normal mode which involves a relative rotation between the IC and fluid outer core about an equatorial axis. It is shown that the small size of the IC's effects on both nutations and tides is a consequence of the fact that the IC's moments of inertia are less than 1/1000 of the entire earth's.

Reliabilities of mental rotation tasks: limits to the assessment of individual differences.

Science.gov (United States)

Hirschfeld, Gerrit; Thielsch, Meinald T; Zernikow, Boris

2013-01-01

Mental rotation tasks with objects and body parts as targets are widely used in cognitive neuropsychology. Even though these tasks are well established to study between-groups differences, the reliability on an individual level is largely unknown. We present a systematic study on the internal consistency and test-retest reliability of individual differences in mental rotation tasks comparing different target types and orders of presentations. In total n = 99 participants (n = 63 for the retest) completed the mental rotation tasks with hands, feet, faces, and cars as targets. Different target types were presented in either randomly mixed blocks or blocks of homogeneous targets. Across all target types, the consistency (split-half reliability) and stability (test-retest reliabilities) were good or acceptable both for intercepts and slopes. At the level of individual targets, only intercepts showed acceptable reliabilities. Blocked presentations resulted in significantly faster and numerically more consistent and stable responses. Mental rotation tasks-especially in blocked variants-can be used to reliably assess individual differences in global processing speed. However, the assessment of the theoretically important slope parameter for individual targets requires further adaptations to mental rotation tests.

Experimental characterization of solid particle transport by slug flow using Particle Image Velocimetry

International Nuclear Information System (INIS)

Goharzadeh, A; Rodgers, P

2009-01-01

This paper presents an experimental study of gas-liquid slug flow on solid particle transport inside a horizontal pipe with two types of experiments conducted. The influence of slug length on solid particle transportation is characterized using high speed photography. Using combined Particle Image Velocimetry (PIV) with Refractive Index Matching (RIM) and fluorescent tracers (two-phase oil-air loop) the velocity distribution inside the slug body is measured. Combining these experimental analyses, an insight is provided into the physical mechanism of solid particle transportation due to slug flow. It was observed that the slug body significantly influences solid particle mobility. The physical mechanism of solid particle transportation was found to be discontinuous. The inactive region (in terms of solid particle transport) upstream of the slug nose was quantified as a function of gas-liquid composition and solid particle size. Measured velocity distributions showed a significant drop in velocity magnitude immediately upstream of the slug nose and therefore the critical velocity for solid particle lifting is reached further upstream.

Rotator cuff exercises

Science.gov (United States)

... 25560729 . Read More Frozen shoulder Rotator cuff problems Rotator cuff repair Shoulder arthroscopy Shoulder CT scan Shoulder MRI scan Shoulder pain Patient Instructions Rotator cuff - self-care Shoulder surgery - discharge Using your ...

Theory of symmetry and of exact solution properties for fast rotating nuclei

International Nuclear Information System (INIS)

Heydon, B.

1995-01-01

We propose a study of rotating multi-fermionic systems. The method we developed is based on unitary group theory. The formalism of Gel'fand-Tsetlin is is simplified to binary calculations. With the help of operator of Casimir and physical interpretations using dichotomic symmetries (signature, parity), we show rotating Hamiltonians obey to a new quantum symmetry called P. The study of short range two-body interaction breaking weakly this symmetry, is made by using single j-shell. Nuclear interactions coupling two j-shell are introduced. This study allows us to compare ours results to experimental data for three isotopes of Zirconium. (author)

Deuteron NMR and modelling in solid polymers

International Nuclear Information System (INIS)

Hirschinger, J.

1992-01-01

Deuteron NMR techniques are described and some recent applications to the study of rotational motions in solid polymers are reviewed. The information content and the domain of applicability of each technique are presented. Ultra-slow motions are studied in real time without any motional model consideration. For very fast motions, computer molecular dynamics simulations are shown to complement the NMR results. Experimental examples deal with the chain motion in the crystalline α-phase of poly(vinylidenefluoride) and nylon 6,6

Translation and rotation of a porous spheroid in a spheroidal container

International Nuclear Information System (INIS)

Saad, E.I.

2010-01-01

The flow problem of an incompressible axisymmetrical quasisteady translation and steady rotation of a porous spheroid in a concentric spheroidal container are studied analytically. The same small departure from a sphere is considered for each spheroidal surface. In the limit of small Reynolds number, the Brinkman equation for the flow inside the porous region and the Stokes equation for the outside region in their stream functions formulations and velocity components, which are proportional to the translational and angular velocities, respectively, are used. Explicit expressions are obtained for both inside and outside flow fields to the first order in a small parameter characterizing the deformation of the spheroidal surface from the spherical shape. The hydrodynamic drag force and couple exerted on the porous spheroid are obtained for the special cases of prolate and oblate spheroids in closed forms. The dependence of the normalized wall-corrected translational and rotational mobilities on permeability for a porous spheroid in an unbounded medium and for a solid spheroid in a cell on the particle volume fraction is discussed numerically and graphically for various values of the deformation parameter. In the limiting cases, the analytical solutions describing the drag force and torque or mobilities for a porous spheroid in the spheroidal vessel reduce to those for a solid sphere and for a porous sphere in a spherical cell. (author)

Translation-rotation plasticity as basic mechanism of plastic deformation in macro-, micro- and nanoindentation processes

International Nuclear Information System (INIS)

Grabco, D; Shikimaka, O; Harea, E

2008-01-01

This paper presents a brief review of multilateral examinations for the purpose of detection of interrelation between processes occuring in solids at different levels of action of exterior loading, namely, at macro-, micro- and nanoindentation. Convincing arguments supporting the rotation deformation mechanism alongside the recognized dislocation one are adduced. It has been shown that the decrease in dislocation mobility leads at all scales to the intensification of rotation plasticity and to the involvement of other plastic deformation mechanisms, such as appearance and interaction of disclinations, twinning, phase transition and compression of material. The conversion from translation plasticity to the rotation-translation one means transition to the higher level of plastic deformation, the mesolevel, when the possibilities of the previous microscopic level are exhausted. It was established that the plastic deformation zone in the vicinity of indentations could be separated into two main specific regions: (i) peripheral region predominantly with the dislocation deformation mechanism; otherwise, translation mechanism: microlevel, and (ii) quasidestructured region mainly with the disclination or the intergranular sliding mechanism: rotation mechanism, mesolevel

Surface geometry of a rotating black hole in a magnetic field

International Nuclear Information System (INIS)

Kulkarni, R.; Dadhich, N.

1986-01-01

We study the intrinsic geometry of the surface of a rotating black hole in a uniform magnetic field, using a metric discovered by Ernst and Wild. Rotating black holes are analogous to material rotating bodies according to Smarr since black holes also tend to become more oblate on being spun up. Our study shows that the presence of a strong magnetic field ensures that a black hole actually becomes increasingly prolate on being spun up. Studying the intrinsic geometry of the black-hole surface also gives rise to an interesting embedding problem. Smarr shows that a Kerr black hole cannot be globally isometrically embedded in R 3 if its specific angular momentum a exceeds (√3 /2)mapprox.0.866. . .m. We show that in the presence of a magnetic field of strength B, satisfying 2- √3 2 m 2 3 for all values of the angular momentum

No Effect of Assisted Hip Rotation on Bat Velocity.

Science.gov (United States)

Rivera, Michelle; Leyva, Whitney D; Archer, David C; Munger, Cameron N; Watkins, Casey M; Wong, Megan A; Dobbs, Ian J; Galpin, Andrew J; Coburn, Jared W; Brown, Lee E

2018-01-01

Softball and baseball are games that require multiple skill sets such as throwing, hitting and fielding. Players spend a copious amount of time in batting practice in order to be successful hitters. Variables commonly associated with successful hitting include bat velocity and torso rotation. The concept of overspeed bodyweight assistance (BWA) has shown increases in vertical jump and sprint times, but not hip rotation and batting. The purpose of this study was to examine the effects of assisted hip rotation on bat velocity. Twenty-one male and female recreational softball and baseball players (15 males, age 23.8 ± 3.1yrs; height 177.67 ± 6.71cm; body mass 85.38 ± 14.83kg; 6 females, age 21.5 ± 2.1yrs; height 162.20 ± 9.82cm; body mass 60.28 ± 9.72kg) volunteered to participate. Four different BWA conditions (0%, 10%, 20%, and 30%) were randomly applied and their effects on bat velocity were analyzed. Subjects performed three maximal effort swings under each condition in a custom measurement device and average bat velocity (MPH) was used for analysis. A mixed factor ANOVA revealed no interaction (p=0.841) or main effect for condition, but there was a main effect for sex where males had greater bat velocity (43.82±4.40 - 0% BWA, 41.52±6.09 - 10% BWA, 42.59±7.24 - 20% BWA, 42.69±6.42 - 30% BWA) than females (32.57±5.33 - 0% BWA, 31.69±3.40 - 10% BWA, 32.43±5.06 - 20% BWA, 32.08±4.83 - 30% BWA) across all conditions Using the concept of overspeed training with assisted hip rotation up to 30% BWA did not result in an increase in bat velocity. Future research should examine elastic band angle and hip translation at set-up.

No Effect of Assisted Hip Rotation on Bat Velocity

Science.gov (United States)

RIVERA, MICHELLE; LEYVA, WHITNEY D.; ARCHER, DAVID C.; MUNGER, CAMERON N.; WATKINS, CASEY M.; WONG, MEGAN A.; DOBBS, IAN J.; GALPIN, ANDREW J.; COBURN, JARED W.; BROWN, LEE E.

2018-01-01

Softball and baseball are games that require multiple skill sets such as throwing, hitting and fielding. Players spend a copious amount of time in batting practice in order to be successful hitters. Variables commonly associated with successful hitting include bat velocity and torso rotation. The concept of overspeed bodyweight assistance (BWA) has shown increases in vertical jump and sprint times, but not hip rotation and batting. The purpose of this study was to examine the effects of assisted hip rotation on bat velocity. Twenty-one male and female recreational softball and baseball players (15 males, age 23.8 ± 3.1yrs; height 177.67 ± 6.71cm; body mass 85.38 ± 14.83kg; 6 females, age 21.5 ± 2.1yrs; height 162.20 ± 9.82cm; body mass 60.28 ± 9.72kg) volunteered to participate. Four different BWA conditions (0%, 10%, 20%, and 30%) were randomly applied and their effects on bat velocity were analyzed. Subjects performed three maximal effort swings under each condition in a custom measurement device and average bat velocity (MPH) was used for analysis. A mixed factor ANOVA revealed no interaction (p=0.841) or main effect for condition, but there was a main effect for sex where males had greater bat velocity (43.82±4.40 - 0% BWA, 41.52±6.09 - 10% BWA, 42.59±7.24 - 20% BWA, 42.69±6.42 - 30% BWA) than females (32.57±5.33 - 0% BWA, 31.69±3.40 - 10% BWA, 32.43±5.06 - 20% BWA, 32.08±4.83 - 30% BWA) across all conditions Using the concept of overspeed training with assisted hip rotation up to 30% BWA did not result in an increase in bat velocity. Future research should examine elastic band angle and hip translation at set-up. PMID:29795730

Arc plasma assisted rotating electrode process for preparation of metal pebbles

International Nuclear Information System (INIS)

Mohanty, T.; Tripathi, B.M.; Mahata, T.; Sinha, P.K.

2014-01-01

Spherical beryllium pebbles of size ranging from 0.2-2 mm are required as neutron multiplying material in solid Test Blanket Module (TBM) of International Thermonuclear Experimental Reactor (ITER). Rotating electrode process (REP) has been identified as a suitable technique for preparation of beryllium pebbles. In REP, arc plasma generated between non-consumable electrode (cathode) and rotating metal electrode (anode) plays a major role for continuous consumption of metal electrode and preparation of spherical metal pebbles. This paper focuses on description of the process, selection of sub-systems for development of REP experimental set up and optimization of arc parameters, such as, cathode geometry, arc current, arc voltage, arc gap and carrier gas flow rate for preparation of required size spherical metal pebbles. Other parameters which affect the pebbles sizes are rotational speed, metal electrode diameter and physical properties of the metal. As beryllium is toxic in nature its surrogate metals such as stainless steel (SS) and Titanium (Ti) were selected to evaluate the performance of the REP equipment. Several experiments were carried out using SS and Ti electrode and process parameters have been optimized for preparation of pebbles of different sizes. (author)

Effect of periodic fluctuation of soil particle rotation resistance on interface shear behaviour

International Nuclear Information System (INIS)

Ebrahimian, Babak; Noorzad, Asadollah

2010-01-01

The interface behaviour between infinite extended narrow granular layer and bounding structure is numerically investigated using finite element method. The micro-polar (Cosserat) continuum approach within the framework of elasto-plasticity is employed to remove the numerical difficulties caused by strain-softening of materials in classical continuum mechanics. Mechanical properties of cohesionless granular soil are described with Lade's model enhanced with polar terms including Cosserat rotations, curvatures and couple stresses via mean grain diameter as the internal length. The main attention of paper is laid on the influence of spatial periodic fluctuation of rotation resistance of soil particles interlocked with the surface of bounding structure on evolution and location of shear band developed inside granular body. The finite element results demonstrate that the location and evolution of shear localization in granular body is strongly affected by prescribed non-uniform micro-polar kinematic boundary conditions along the interface.

Rotational stabilization of q < 1 modes

International Nuclear Information System (INIS)

Waelbroeck, F.L.; Aydemir, A.Y.

1996-01-01

Analyses of high performance discharges with central safety factor below unity have shown that the ideal Magnetohydrodynamic stability threshold for the n=1 kink mode is often violated with impunity. For TFTR (Tokamak Fusion Test Reactor) supershots, the experimental observations can be explained by diamagnetic stabilization of the reconnecting model provided that the fluid free energy is suitably reduced by trapped particle effects. For the broader profiles typical of other high confinement regimes, however, diamagnetic effects cannot account for the experimental results. Furthermore, there is evidence that the Mercier stability condition can also be violated in some cases. Here, we show that toroidal rotation of the plasma can stabilize the kink mode even in the presence of resistivity in configurations that would otherwise be ideally unstable. Two effects can be distinguished. The first effect consists in a reduction of the ideal driving energy. This can be understood in view of the fact that, to a good approximation, the internal kink is a rigid body displacement combining a tilt of the plasma inside the q = 1 surface with a translation along the tilt axis. In the presence of rotation, this displacement must be accompanied by a precessional motion so as to conserve angular momentum. The kinetic energy of the precessional motion must be extracted from the energy driving the displacement. The second effect of rotation is to resolve the Alfven singularity. This is a consequence of the pressure perturbation caused by the equilibrium variation of the entropy within the flux surfaces. It results in the stabilization of resistive as well as weak ideal instabilities, including Mercier modes. For rotationally stabilized equilibria, it also implies the presence of a neutrally stable mode with frequency of the order of the growth rate of the internal kink

Fatigue criterion for the design of rotating shafts under combined stress

Science.gov (United States)

Loewenthal, S. H.

1977-01-01

A revised approach to the design of transmission shafting which considers the flexure fatigue characteristics of the shaft material under combined cyclic bending and static torsion stress is presented. A fatigue failure relation, corroborated by published combined stress test data, is presented which shows an elliptical variation of reversed bending endurance strength with static torsional stress. From this elliptical failure relations, a design formula for computing the diameter of rotating solid shafts under the most common condition of loading is developed.

Poisson equations of rotational motion for a rigid triaxial body with application to a tumbling artificial satellite

Science.gov (United States)

Liu, J. J. F.; Fitzpatrick, P. M.

1975-01-01

A mathematical model is developed for studying the effects of gravity gradient torque on the attitude stability of a tumbling triaxial rigid satellite. Poisson equations are used to investigate the rotation of the satellite (which is in elliptical orbit about an attracting point mass) about its center of mass. An averaging method is employed to obtain an intermediate set of differential equations for the nonresonant, secular behavior of the osculating elements which describe the rotational motions of the satellite, and the averaged equations are then integrated to obtain long-term secular solutions for the osculating elements.

Development of basic theories and techniques for determining stresses in rotating turbine or compressor blades

Science.gov (United States)

Chien, C. H.; Swinson, W. F.; Turner, J. L.; Moslehy, F. A.; Ranson, W. F.

1980-01-01

A method for measuring in-plane displacement of a rotating structure by using two laser speckle photographs is described. From the displacement measurements one can calculate strains and stresses due to a centrifugal load. This technique involves making separate speckle photographs of a test model. One photograph is made with the model loaded (model is rotating); the second photograph is made with no load on the model (model is stationary). A sandwich is constructed from the two speckle photographs and data are recovered in a manner similar to that used with conventional speckle photography. The basic theory, experimental procedures of this method, and data analysis of a simple rotating specimen are described. In addition the measurement of in-plane surface displacement components of a deformed solid, and the application of the coupled laser speckle interferometry and boundary-integral solution technique to two dimensional elasticity problems are addressed.

Shoulder-Rotator Strength, Range of Motion, and Acromiohumeral Distance in Asymptomatic Adolescent Volleyball Attackers.

Science.gov (United States)

Harput, Gulcan; Guney, Hande; Toprak, Ugur; Kaya, Tunca; Colakoglu, Fatma Filiz; Baltaci, Gul

2016-09-01

Sport-specific adaptations at the glenohumeral joint could occur in adolescent athletes because they start participating in high-performance sports in early childhood. To investigate shoulder-rotator strength, internal-rotation (IR) and external-rotation (ER) range of motion (ROM), and acromiohumeral distance (AHD) in asymptomatic adolescent volleyball attackers to determine if they have risk factors for injury. Cross-sectional study. University laboratory. Thirty-nine adolescent high school-aged volleyball attackers (22 boys, 17 girls; age = 16.0 ± 1.4 years, height = 179.2 ± 9.0 cm, mass = 67.1 ± 10.9 kg, body mass index = 20.7 ± 2.6 kg/m 2 ). Shoulder IR and ER ROM, total-rotation ROM, glenohumeral IR deficit, AHD, and concentric and eccentric strength of the shoulder internal and external rotators were tested bilaterally. External-rotation ROM was greater (t 38 = 4.92, P 18°). We observed greater concentric internal-rotator (t 38 = 2.89, P = .006) and eccentric external-rotator (t 38 = 2.65, P = .01) strength in the dominant than in the nondominant shoulder. The AHD was less in the dominant shoulder (t 38 = -3.60, P volleyball attackers demonstrated decreased IR ROM, total ROM, and AHD and increased ER ROM in their dominant shoulder. Therefore, routine screening of adolescent athletes and designing training programs for hazardous adaptive changes could be important in preventing shoulder injuries.

Probing Vitamine C, Aspirin and Paracetamol in the Gas Phase: High Resolution Rotational Studies

Science.gov (United States)

Mata, S.; Cabezas, C.; Varela, M.; Pena, I.; Nino, A.; López, J. C.; Alonso, J. L.; Grabow, J.-U.

2011-06-01

A solid sample of Vitamin C (m.p. 190°C) vaporized by laser ablation has been investigated in gas phase and characterized through their rotational spectra. Two spectroscopy techniques has been used to obtain the spectra: a new design of broadband chirped pulse Fourier transform microwave spectroscopy with in-phase/quadrature-phase-modulation passage-acquired-coherence technique (IMPACT) and conventional laser ablation molecular beam Fourier transform microwave spectroscopy (LA-MB-FTMW). Up to now, two low-energy conformer have been observed and their rotational constants determined. Ab initio calculations at the MP2/6-311++G (d,p) level of theory predicted rotational constants which helped us to identify these conformers unequivocally. Among the molecules to benefit from the LA-MB-FTMW technique there are common important drugs never observed in the gas phase through rotational spectroscopy. We present here the results on acetyl salicylic acid and acetaminophen (m.p. 136°C), commonly known as aspirin and paracetamol respectively. We have observed two stable conformers of aspirin and two for paracetamol. The internal rotation barrier of the methyl group in aspirin has been determined for both conformers from the analysis of the A-E splittings due to the coupling of internal and overall rotation. J. L. Alonso, C. Pérez, M. E. Sanz, J. C. López, S. Blanco, Phys. Chem. Chem. Phys. 11,617-627 (2009)and references therein

On the Lippmann--Schwinger equation for atom--diatom collisions: A rotating frame treatment

International Nuclear Information System (INIS)

Kouri, D.J.; Heil, T.G.; Shimoni, Y.

1976-01-01

The use of a rotating frame description of molecular collisions is reconsidered within the framework of the Lippmann--Schwinger equation for the transition or T operator. The present approach explicitly displays the proper boundary conditions which apply to descriptions of such collisions in the rotating frame whose Z axis follows the scattering vector. The resulting body frame equations are shown to lead naturally to the introduction of ''body frame Bessel and Hankel functions,'' J/subJ//subj//sup lambda//sup lambda//sup prime/ and H/subJ//subj//sup lambda//sup lambda//sup prime/ (BFBF), which are solutions of the unperturbed Hamiltonian for the collision transformed to the rotating frame. It is found that the BFBF can be defined in several ways differing by phase factors that affect their asymptotic form. Two particular choices are examined, one of which leads to a simple asymptotic form of the wavefunction, and the other leads to a somewhat more complicated form. Both are shown to yield the j/subz/-conserving coupled states equations of McGuire and Kouri but slightly different approximations are required in the two cases. The implication of these results as to the accuracy of the j/subz/CCS method are discussed

Attitude and gyro bias estimation by the rotation of an inertial measurement unit

International Nuclear Information System (INIS)

Wu, Zheming; Sun, Zhenguo; Zhang, Wenzeng; Chen, Qiang

2015-01-01

In navigation applications, the presence of an unknown bias in the measurement of rate gyros is a key performance-limiting factor. In order to estimate the gyro bias and improve the accuracy of attitude measurement, we proposed a new method which uses the rotation of an inertial measurement unit, which is independent from rigid body motion. By actively changing the orientation of the inertial measurement unit (IMU), the proposed method generates sufficient relations between the gyro bias and tilt angle (roll and pitch) error via ridge body dynamics, and the gyro bias, including the bias that causes the heading error, can be estimated and compensated. The rotation inertial measurement unit method makes the gravity vector measured from the IMU continuously change in a body-fixed frame. By theoretically analyzing the mathematic model, the convergence of the attitude and gyro bias to the true values is proven. The proposed method provides a good attitude estimation using only measurements from an IMU, when other sensors such as magnetometers and GPS are unreliable. The performance of the proposed method is illustrated under realistic robotic motions and the results demonstrate an improvement in the accuracy of the attitude estimation. (paper)

Influence of rotation on the near-wake development behind an impulsively started circular cylinder

Science.gov (United States)

Coutanceau, M.; Menard, C.

1985-09-01

A rotating body, travelling through a fluid in such a way that the rotation axis is at right angles to the translational path, experiences a transverse force, called the Magnus force. The present study is concerned with a rotating cylinder which is in a state of translational motion. In the considered case, the existence of a lift force may be explained easily on the basis of the theory of inviscid fluids. An experimental investigation provides new information regarding the mechanism of the near-wake development of the classical unsteady flow and the influence of the rotational effects. Attention is given to the experimental technique, aspects of flow topology and notation, the time development of the wake flow pattern, the time evolution of certain flow properties, the flow structure in the neighborhood of the front stagnation point, and the influence of the Reynolds number on flow establishment.

Theory of symmetry and of exact solution properties for fast rotating nuclei; Theorie de la symetrie et des proprietes de solutions exactes pour les noyaux en rotation rapide

Energy Technology Data Exchange (ETDEWEB)

Heydon, B

1995-07-19

We propose a study of rotating multi-fermionic systems. The method we developed is based on unitary group theory. The formalism of Gel`fand-Tsetlin is is simplified to binary calculations. With the help of operator of Casimir and physical interpretations using dichotomic symmetries (signature, parity), we show rotating Hamiltonians obey to a new quantum symmetry called P. The study of short range two-body interaction breaking weakly this symmetry, is made by using single j-shell. Nuclear interactions coupling two j-shell are introduced. This study allows us to compare ours results to experimental data for three isotopes of Zirconium. (author). 155 refs.

Lunar Core and Tides

Science.gov (United States)

Williams, J. G.; Boggs, D. H.; Ratcliff, J. T.

2004-01-01

Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2,3,4] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening, which in the past has been marginal but improving [3,4,5], now seems significant. Direct detection of the core moment has not yet been achieved.

Photothermoacoustic effect in solids with piezoelectric detection

International Nuclear Information System (INIS)

Kozachenko, V. V.; Kucherov, I.Ya.

2004-01-01

Full text: In the last few years, a growing interest has been expressed in studies of substances in different aggregate states which were performed with the help of the photothermoacoustic PTA effect. Main in this method is use of thermal waves as the carrier of the information about properties of explored substance. The excitation of thermal waves is carried out, as a rule, by modulated light flux. A specific feature of the PTA effect is the dependence of the information obtained from it on the method used for detecting thermal waves. One of the most sensitive methods for detecting a PTA signal is the piezoelectric method. For studies of solids, the PTA effect in plates offers considerable promise. In this work, PTA effect in a solid-piezoelectric layered structure is studied theoretically and experimentally. The layered plate consisting of an isotropic solid and piezoelectric crystal of a class 6 mm (or piezoelectric ceramics) is considered. The surface of a solid body is uniformly irradiated with a modulated light flux. The sample is heated and the thermal waves are generated. In the sample, the temperature field of thermal waves generates, due to the thermoelastic effect, acoustic vibration and waves that are registered by a piezoelectric. Expressions for the potential difference U across an arbitrary layer of piezoelectric transducer are derived. The solid bodies with various optical and thermal properties for cases of one-layer and two-layer piezoelectric transducer are analyzed. In particular, is shown, that for the case two-layer piezoelectric transducer, in the high-frequency region, the amplitude ratio U 1 / U 2 the tangent of the phase difference tg(Δφ) of signals taken from individual layers of the transducer depend almost linearly on the inverse square root of the frequency f -1/2 . With use of these features, the new method of definition of some elastic and thermal parameters of solid bodies offered. An experiment is performed with samples Cu, Fe

Surface dimpling on rotating work piece using rotation cutting tool

Science.gov (United States)

Bhapkar, Rohit Arun; Larsen, Eric Richard

2015-03-31

A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupled to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.

Electron spin dynamics of Ce.sup.3+./sup. ions in YAG crystals studied by pulse-EPR and pump-probe Faraday rotation

Czech Academy of Sciences Publication Activity Database

Azamat, Dmitry; Belykh, V.V.; Yakovlev, D.R.; Fobbe, F.; Feng, D.H.; Evers, E.; Jastrabík, Lubomír; Dejneka, Alexandr; Bayer, M.

2017-01-01

Roč. 96, č. 7 (2017), s. 1-10, č. článku 075160. ISSN 2469-9950 R&D Projects: GA MŠk LO1409; GA ČR GA16-22092S Institutional support: RVO:68378271 Keywords : electron spin dynamics * Ce 3+ ions * YAG crystals * pulse-EPR * Faraday rotation Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 3.836, year: 2016

Method of and apparatus for examining a body by radiation such as x or gamma radiation

International Nuclear Information System (INIS)

Hounsfield, G.N.

1975-01-01

Apparatus is disclosed for examining a body by means of radiation such as X or γ radiation. The body to be examined is inserted in an aperture in a scanning and locating structure, which structure supports a source of the radiation and detector means therefor on opposite sides of the aperture. The source and detector means are moveable to and fro on the structure so as to scan the radiation laterally across the body in a plane and the structure is rotatable around the body about an axis perpendicular to the plane. Disposed between the source and detector means is an attenuator means which extends laterally in said plane to the full extent of the lateral scanning motion and rotates with the structure

Water reuse potential in truck wash using a Rotating Biological Contactor

OpenAIRE

Eduardo Lucas Subtil; José Carlos Mierzwa; Ivanildo Hespanhol; Raphael Rodrigues

2016-01-01

This study evaluated the water reuse potential for truck washing using the effluent treated by a Rotating Biological Contactor (RBC) operated in full scale. In order to evaluate the reuse potential, a mass balance was performed for the reuse system taking into account the concentration of Total Dissolved Solids as the critical contaminant. The treatment system produced an effluent with average concentration of color, turbidity, TDS and BOD5 of 45 ± 14 uC, 15 ± 6.0 NTU, 244 ± 99 mg TDS / L and...

Solid state NMR, basic theory and recent progress for quadrupole nuclei with half-integer spin

International Nuclear Information System (INIS)

Dieter, F.

1998-01-01

This review describes the basic theory and some recently developed techniques for the study of quadrupole nuclei with half integer spins in powder materials. The latter is connected to the introduction of the double rotation (DOR) by A. Samoson et al. (1) and to the introduction of the multiple quantum magic-angle spinning (MQ MAS) technique by L. Frydman et. al. (2). For integer spins, especially the solid-state deuterium magnetic resonance, we refer to the review of G.L. Hoatson and R.L. Vold: '' 2 H-NMR Spectroscopy of Solids and Liquid Crystals'' (3). For single crystals we refer to O. Kanert and M. Mehring: ''Static quadrupole effects in disordered cubic solids''(4) and we would like also to mention the ''classic'' review of M.H. Cohen and F. Reif: ''Quadrupole effects in NMR studies of solids'' (5). Some more recent reviews in the field under study are D. Freude and J. Haase ''Quadrupole effects in solid-state NMR'' (6). Ch. Jager: ''Satellite Transition Spectroscopy of Quadrupolar Nuclei'' (7) and B.F. Chmelka and J.W. Zwanziger: ''Solid State NMR Line Narrowing Methods for Quadrupolar Nuclei - Double Rotation and Dynamic-Angle Spinning'' (8). A survey of nuclear quadrupole frequency data published before the end of 1982 is given by H. Chihara and N. Nakamura in Landolt-Bornstein, Vol. 20 (9). Values of the chemical shift of quadrupole nuclei in solids can be found in books such as ''Multinuclear NMR'' edited by J. Mason (10). In section 9 of ref (6) some electric field gradient and chemical shift data published from 1983 to 1992 for the most studied quadrupole nuclei sup 27 Al, sup 23 Na, and sup 17 O are given

Improved process for contacting finely divided solid particles with gases

Energy Technology Data Exchange (ETDEWEB)

1952-07-30

A process of contacting solids and gases of the type in which finely divided solids are maintained in a dense fluidized state in a treating zone by means of an upflowing gaseous fluidizing medium wherein solid packing in the form of a body static contiguous elements is maintained in the treating zone. The size, shape, and arrangement of the elements constituting the packing being such as to define a labyrinth of passageways in which the finely divided solids are maintained in a fluidized state, and the finely divided solids are adapted to flow freely downwardly through the passageways in the absence of a gaseous fluidizing medium.

The rotating universe

International Nuclear Information System (INIS)

Ruben, G.; Treder, H.J.

1987-01-01

For a long time the question whether the universe rotates or not is discussed. Aspects of Huygens, Newton, Mach and other important historical scientists in this field are reported. The investigations of the mathematician Kurt Groedel in order to prove the rotation of the universe are illustrated. Kurt Groedel has shown that Einstein's gravitational equations of general relativity theory and the cosmological postulate of global homogeneity of cosmic matter (that is the Copernical principle) are not contradictionary to a rotating universe. Abberation measurements, position determination by means of radiointerferometry and methods for the determination of the rotation of the universe from the isotropy of the background radiation are presented. From these experiments it can be concluded that the universe seems not to rotate as already Einstein expected

Rotation sensor switch

International Nuclear Information System (INIS)

Sevec, J.B.

1978-01-01

A protective device to provide a warning if a piece of rotating machinery slows or stops is comprised of a pair of hinged weights disposed to rotate on a rotating shaft of the equipment. When the equipment is rotating, the weights remain in a plane essentially perpendicular to the shaft and constitute part of an electrical circuit that is open. When the shaft slows or stops, the weights are attracted to a pair of concentric electrically conducting disks disposed in a plane perpendicular to the shaft and parallel to the plane of the weights when rotating. A disk magnet attracts the weights to the electrically conducting plates and maintains the electrical contact at the plates to complete an electrical circuit that can then provide an alarm signal

Rotating thermal convection at very large Rayleigh numbers

Science.gov (United States)

Weiss, Stephan; van Gils, Dennis; Ahlers, Guenter; Bodenschatz, Eberhard

2016-11-01

The large scale thermal convection systems in geo- and astrophysics are usually influenced by Coriolis forces caused by the rotation of their celestial bodies. To better understand the influence of rotation on the convective flow field and the heat transport at these conditions, we study Rayleigh-Bénard convection, using pressurized sulfur hexaflouride (SF6) at up to 19 bars in a cylinder of diameter D=1.12 m and a height of L=2.24 m. The gas is heated from below and cooled from above and the convection cell sits on a rotating table inside a large pressure vessel (the "Uboot of Göttingen"). With this setup Rayleigh numbers of up to Ra =1015 can be reached, while Ekman numbers as low as Ek =10-8 are possible. The Prandtl number in these experiment is kept constant at Pr = 0 . 8 . We report on heat flux measurements (expressed by the Nusselt number Nu) as well as measurements from more than 150 temperature probes inside the flow. We thank the Deutsche Forschungsgemeinschaft (DFG) for financial support through SFB963: "Astrophysical Flow Instabilities and Turbulence". The work of GA was supported in part by the US National Science Foundation through Grant DMR11-58514.

The Little Heat Engine: Heat Transfer in Solids, Liquids and Gases

Directory of Open Access Journals (Sweden)

Robitaille P.-M.

2007-10-01

Full Text Available In this work, an introductory exposition of the laws of thermodynamics and radiative heat transfer is presented while exploring the concepts of the ideal solid, the lattice, and the vibrational, translational, and rotational degrees of freedom. Analysis of heat transfer in this manner helps scientists to recognize that the laws of thermal radiation are strictly applicable only to the ideal solid. On the Earth, such a solid is best represented by either graphite or soot. Indeed, certain forms of graphite can approach perfect absorption over a relatively large frequency range. Nonetheless, in dealing with heat, solids will eventually sublime or melt. Similarly, liquids will give way to the gas phase. That thermal conductivity eventually decreases in the solid signals an inability to further dissipate heat and the coming breakdown of Planck’s law. Ultimately, this breakdown is reflected in the thermal emission of gases. Interestingly, total gaseous emissivity can de- crease with increasing temperature. Consequently, neither solids, liquids, or gases can maintain the behavior predicted by the laws of thermal emission. Since the laws of thermal emission are, in fact, not universal, the extension of these principles to non-solids constitutes a serious overextension of the work of Kirchhoff, Wien, Stefan and Planck.

Q-deformed algebras and many-body physics

Energy Technology Data Exchange (ETDEWEB)

Galetti, D; Lunardi, J T; Pimentel, B M [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Lima, C L [Sao Paulo Univ., SP (Brazil). Inst. de Fisica

1995-11-01

A review is presented of some applications of q-deformed algebras to many-body systems. The rotational and pairing nuclear problems will be discussed in the context of q-deformed algebras, before presenting a more microscopically based application of q-deformed concepts to many-fermion systems. (author). 30 refs., 5 figs.

Many-body theory

International Nuclear Information System (INIS)

Hubbard, J.

1980-01-01

The evolution of the discipline of many-body theory during the past 25 years is outlined and the developments originated in the Theoretical Physics Division, AERE, are discussed. Topics considered include; the connection between plasma oscillations and the dielectric properties of an electron gas, superconductivity, Fermi levels, ferromagnetism in metals, phase transformations, scaling laws, and quasi-one-dimensional solids. (UK)

Hydromagnetic quasi-geostrophic modes in rapidly rotating planetary cores

DEFF Research Database (Denmark)

Canet, E.; Finlay, Chris; Fournier, A.

2014-01-01

The core of a terrestrial-type planet consists of a spherical shell of rapidly rotating, electrically conducting, fluid. Such a body supports two distinct classes of quasi-geostrophic (QG) eigenmodes: fast, primarily hydrodynamic, inertial modes with period related to the rotation time scale...... decreases toward the outer boundary in a spherical shell, QG modes tend to be compressed towards the outer boundary. Including magnetic dissipation, we find a continuous transition from diffusionless slow magnetic modes into quasi-free decay magnetic modes. During that transition (which is controlled......, or shorter than, their oscillation time scale.Based on our analysis, we expect Mercury to be in a regime where the slow magnetic modes are of quasi-free decay type. Earth and possibly Ganymede, with their larger Elsasser numbers, may possess slow modes that are in the transition regime of weak diffusion...

The formation of molecular hydrogen on silicate dust analogs: The rotational distribution

Energy Technology Data Exchange (ETDEWEB)

Gavilan, L.; Lemaire, J. L. [LERMA, UMR 8112 du CNRS, de l' Observatoire de Paris et de l' Université de Cergy Pontoise, 5 mail Gay Lussac, F-95000 Cergy Pontoise Cedex (France); Vidali, G. [Visiting Professor. Permanent address: Syracuse University, Physics Department, Syracuse, NY 13244-1320, USA. (United States); Sabri, T.; Jæger, C., E-mail: lisseth.gavilan@obspm.fr [Laboratory Astrophysics and Cluster Physics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena (Germany)

2014-02-01

Our laboratory experiments continue to explore how the formation of molecular hydrogen is influenced by dust and how dust thereby affects hydrogen molecules adsorbed on its surface. In Sabri et al., we present the preparation of nanometer-sized silicate grain analogs via laser ablation. These analogs illustrate extremes in structure (fully crystalline or fully amorphous grains), and stoichiometry (the forsterite and fayalite end-members of the olivine family). These were inserted in FORMOLISM, an ultra-high vacuum setup where they can be cooled down to ∼5 K. Atomic beams are directed at these surfaces and the formation of new molecules is studied via REMPI(2+1) spectroscopy. We explored the rotational distribution (0 ≤ J'' ≤ 5) of v'' = 0 of the ground electronic state of H{sub 2}. The results of these measurements are reported here. Surprisingly, molecules formed and ejected from crystalline silicates have a cold (T {sub rot} ∼ 120 K) rotational energy distribution, while for molecules formed on and ejected from amorphous silicate films, the rotational temperature is ∼310 K. These results are compared to previous experiments on metallic surfaces and theoretical simulations. Solid-state surface analysis suggests that flatter grains could hinder the 'cartwheel' rotation mode. A search for hot hydrogen, predicted as a result of H{sub 2} formation, hints at its production. For the first time, the rotational distribution of hydrogen molecules formed on silicate dust is reported. These results are essential to understanding the chemistry of astrophysical media containing bare dust grains.

Body-force-driven multiplicity and stability of combined free and forced convection in rotating curved ducts: Coriolis force

Science.gov (United States)

Yang, T.; Wang, L.

A numerical study is made on the fully developed bifurcation structure and stability of forced convection in a rotating curved duct of square cross-section. Solution structure is determined as variation of a parameter that indicates the effect of rotation (Coriolis-force-driven multiplicity). Three solutions for the flows in a stationary curved duct obtained in the work of Yang and Wang [1] are used as initial solutions of continuation calculations to unfold the solution branches. Twenty-one solution branches are found comparing with five obtained by Selmi and Nandakumar [2]. Dynamic responses of the multiple solutions to finite random disturbances are examined by the direct transient computation. Results show that characteristics of physically realizable fully developed flows changes significantly with variation of effect of rotation. Fourteen sub-ranges are identified according to characteristics of physically realizable solutions. As rotation effect changes, possible physically realizable fully-developed flows can be stable steady 2-cell state, stable multi-cell state, temporal periodic oscillation between symmetric/asymmetric 2-cell/4-cell flows, temporal oscillation with intermittency, temporal chaotic oscillation and temporal oscillation with pseudo intermittency. Among these possible physically realizable fully developed flows, stable multi-cell state and stable steady 2-cell state exist as dual stable. And oscillation with pseudo intermittency is a new phenomenon. In addition to the temporal oscillation with intermittency, sudden shift from stationary stable solution to temporal chaotic oscillation is identified to be another way of onset of chaos.

Plasma density measurements on refuelling by solid hydrogen pellets in a rotating plasma

International Nuclear Information System (INIS)

Joergensen, L.W.; Sillesen, A.H.

1978-01-01

The refuelling of a plasma by solid hydrogen pellets situated in the plasma is investigated. Nearly half of the pellet material is evaporated and seems to be completely ionized, resulting in an increase of the amount of plasma equivalent to one third of the total amount of plasma without refuelling. The gross behaviour of the plasma is not changed. (author)

MO-D-213-05: Sensitivity of Routine IMRT QA Metrics to Couch and Collimator Rotations

International Nuclear Information System (INIS)

Alaei, P

2015-01-01

Purpose: To assess the sensitivity of gamma index and other IMRT QA metrics to couch and collimator rotations. Methods: Two brain IMRT plans with couch and/or collimator rotations in one or more of the fields were evaluated using the IBA MatriXX ion chamber array and its associated software (OmniPro-I’mRT). The plans were subjected to routine QA by 1) Creating a composite planar dose in the treatment planning system (TPS) with the couch/collimator rotations and 2) Creating the planar dose after “zeroing” the rotations. Plan deliveries to MatriXX were performed with all rotations set to zero on a Varian 21ex linear accelerator. This in effect created TPS-created planar doses with an induced rotation error. Point dose measurements for the delivered plans were also performed in a solid water phantom. Results: The IMRT QA of the plans with couch and collimator rotations showed clear discrepancies in the planar dose and 2D dose profile overlays. The gamma analysis, however, did pass with the criteria of 3%/3mm (for 95% of the points), albeit with a lower percentage pass rate, when one or two of the fields had a rotation. Similar results were obtained with tighter criteria of 2%/2mm. Other QA metrics such as percentage difference or distance-to-agreement (DTA) histograms produced similar results. The point dose measurements did not obviously indicate the error due to location of dose measurement (on the central axis) and the size of the ion chamber used (0.6 cc). Conclusion: Relying on Gamma analysis, percentage difference, or DTA to determine the passing of an IMRT QA may miss critical errors in the plan delivery due to couch/collimator rotations. A combination of analyses for composite QA plans, or per-beam analysis, would detect these errors

Impact of rotational grazing on management of gastrointestinal nematodes in weaned lambs.

Science.gov (United States)

Burke, J M; Miller, J E; Terrill, T H

2009-07-07

Gastrointestinal nematode (GIN) control for 'natural' or organic lamb production is needed, especially where Haemonchus contortus is prevalent. The objective was to determine the impact of rotational grazing on GIN infection of weaned lambs. In year 1, naturally infected Katahdin lambs (120 days of age) were randomly assigned to graze (1) continuous bermudagrass (CB; n=14), (2) rotational bermudagrass moved every 3.5 days and returned to original plot 35 days later for three rotations (RB; n=14), or (3) rotational bermudagrass rotated when forage height fell below 10 cm (RBH; n=7) where first day of grazing=Day 0. In late summer, all lambs were supplemented with 500 g corn/SBM because of poor condition. The following year, similar animals were used and included the CB (n=18) and the RB (n=36) groups only. In both years, fecal egg counts (FECs) and blood packed cell volume (PCV) were determined every 7-14 days and body weight every 28 days. Individuals were dewormed with 0.5 g copper oxide wire particles (COWP) when FAMACHA score increased to 3 or more. Between 0 and 3 deworming treatments per lamb were necessary and there tended to be fewer RB than CB lambs dewormed by Day 84 for both years combined (Pdays of grazing. Abomasal worm burden tended to be greater in RB than CB or RBH tracer lambs (P<0.10), but intestinal worm numbers were similar. Differences may be due to differences in grazing patterns among groups. Body weight gains were similar between CB and RB groups. Economic value between the CB and RB lambs was similar based on number of lambs that could have been marketed as organic. For both years, lambs relied exclusively on COWP for GIN control with the exception of one lamb. In summary, while there was a reduced incidence of deworming in the RB compared with the CB group of lambs, estimated economic value of these systems was similar.

Topological Qubits from Valence Bond Solids

Science.gov (United States)

Wang, Dong-Sheng; Affleck, Ian; Raussendorf, Robert

2018-05-01

Topological qubits based on S U (N )-symmetric valence-bond solid models are constructed. A logical topological qubit is the ground subspace with twofold degeneracy, which is due to the spontaneous breaking of a global parity symmetry. A logical Z rotation by an angle 2 π /N , for any integer N >2 , is provided by a global twist operation, which is of a topological nature and protected by the energy gap. A general concatenation scheme with standard quantum error-correction codes is also proposed, which can lead to better codes. Generic error-correction properties of symmetry-protected topological order are also demonstrated.

Male Body Contouring.

Science.gov (United States)

Singh, Babu; Keaney, Terrence; Rossi, Anthony M

2015-09-01

Men are increasingly turning to dermatologists and plastic surgeons to request procedures that correct or enhance physical features. With the advent of this emerging new patient population, alterations in preexisting aesthetic techniques, gender-specific uses of existing devices and overall approaches need to be revisited and adapted to obtain results that are suitable for the male patient. Recently, body contouring has become one of the most sought out procedures by men. Although the majority of clinical studies involving body contouring esthetics are performed with female patients, gains from such studies can be extrapolated to men. Body contouring can be broadly classified as non-invasive or invasive, depending on the modality used. Non-invasive contouring is most frequently performed with devices that target subcutaneous adipose with focused electrical or thermal energy, including low-level laser, cryolipolysis, ultrasonography, and radiofrequency. Invasive body contouring modalities useful for male body contouring include liposuction, pectoral and abdominal wall etching, jawline fillers, synthetic deoxycholic acid injections, and solid silicone implants. The purpose of this review is to bring attention to the unique aspects, strategies, and modalities used in aesthetic body contouring for the male patient.

Detecting and Sonifying Temporal Patterns of Body Segments When Batting

Directory of Open Access Journals (Sweden)

Akemi Kobayashi

2018-02-01

Full Text Available To improve skill in sport activities it is essential to discern the temporal patterns of one’s own movements. Our previous motion capture experiment involving elite female softball players identified key differences in the temporal body movements between the top players and young players against fastballs/change-ups. In this paper, we found that key features could be extracted from the rotation of the pelvis and we developed a sonification feedback system with two nine-axes inertial sensors. Rotation patterns are converted into two synthesized sounds to represent the time at peak trunk rotation speed and impact time. We conducted a pilot experiment with this feedback proposal using expert and novice batters, male and female whether the participants can pace of the rotational motion in batting. As a result, this feedback approach may allow the user to alter the time of peak trunk rotation speed to more closely match the cue provided by the training sound.

Numerical simulation of 3D unsteady flow in a rotating pump by dynamic mesh technique

International Nuclear Information System (INIS)

Huang, S; Guo, J; Yang, F X

2013-01-01

In this paper, the numerical simulation of unsteady flow for three kinds of typical rotating pumps, roots blower, roto-jet pump and centrifugal pump, were performed using the three-dimensional Dynamic Mesh technique. In the unsteady simulation, all the computational domains, as stationary, were set in one inertial reference frame. The motions of the solid boundaries were defined by the Profile file in FLUENT commercial code, in which the rotational orientation and speed of the rotors were specified. Three methods (Spring-based Smoothing, Dynamic Layering and Local Re-meshing) were used to achieve mesh deformation and re-meshing. The unsteady solutions of flow field and pressure distribution were solved. After a start-up stage, the flow parameters exhibit time-periodic behaviour corresponding to blade passing frequency of rotor. This work shows that Dynamic Mesh technique could achieve numerical simulation of three-dimensional unsteady flow field in various kinds of rotating pumps and have a strong versatility and broad application prospects

Rotationally invariant correlation filtering

International Nuclear Information System (INIS)

Schils, G.F.; Sweeney, D.W.

1985-01-01

A method is presented for analyzing and designing optical correlation filters that have tailored rotational invariance properties. The concept of a correlation of an image with a rotation of itself is introduced. A unified theory of rotation-invariant filtering is then formulated. The unified approach describes matched filters (with no rotation invariance) and circular-harmonic filters (with full rotation invariance) as special cases. The continuum of intermediate cases is described in terms of a cyclic convolution operation over angle. The angular filtering approach allows an exact choice for the continuous trade-off between loss of the correlation energy (or specificity regarding the image) and the amount of rotational invariance desired

Planar half-cell shaped precursor body

DEFF Research Database (Denmark)

2015-01-01

The invention relates to a half-cell shaped precursor body of either anode type or cathode type, the half-cell shaped precursor body being prepared to be free sintered to form a sintered or pre-sintered half-cell being adapted to be stacked in a solid oxide fuel cell stack. The obtained half......-cell has an improved planar shape, which remains planar also after a sintering process and during temperature fluctuations....

Gravitomagnetic Field of the Universe and Coriolis Force on the Rotating Earth

Science.gov (United States)

Veto, B.

2011-01-01

The Machian effect of distant masses of the universe in the frame of reference of the rotating Earth is demonstrated using the gravitomagnetic approach of general relativity. This effect appears in the form of a gravitomagnetic Lorentz force acting on moving bodies on the Earth. The gravitomagnetic field of the universe--deduced from a simple…

The Spectrum of Electromagnetic Scatter from an Ensemble of Bodies with Angular Periodicity, as a Model for Jet Engine Modulation

National Research Council Canada - National Science Library

Cashman, John

2001-01-01

A rotating ensemble of bodies of arbitrary shape with angular periodicity scatters an electromagnetic wave to produce a spectrum of frequency components characteristic of the structure and its rotation...

Fluctuations and thermodynamic response functions in a Lennard-Jones solid

International Nuclear Information System (INIS)

Li, M.; Johnson, W.L.

1992-01-01

Thermodynamic response functions of a nearest-neighbor Lennard-Jones solid--heat capacity, thermal-expansion coefficient, compressibility, and elastic constants--are calculated directly from fluctuations using molecular-dynamics simulations. The algorithm used is the earlier Parrinello-Rahman molecular dynamics modified to take into account symmetry and rotation invariance of the system under investigation. The convergence is very fast and results are in good agreement with existing Monte Carlo and molecular-dynamics results

Muon spin rotation studies of defect states in solids: the story of anomalous muonium

International Nuclear Information System (INIS)

Estle, T.L.

1983-01-01

Muon spin rotation (μSR) is a powerful technique to study magnetic phenomena, light interstitial diffusion, and hydrogenic chemistry. However it has been applied in several other areas of science where its applicability was not immediately apparent. One of these is the study of an unusual muonic defect, anomalous muonium, produced when μ + stops in semiconducting crystals. The study of anomalous muonium and the process of inferring its structure are described. For this defect, μSR has learned far more than have efforts to study the analogous hydrogenic center

Improved models for determination of body fat by in vivo neutron activation

International Nuclear Information System (INIS)

Cohn, S.; Vaswani, A.; Yasumura, S.; Yuen, K.; Ellis, K.

1984-01-01

In the present study, two different models of body composition, based on data obtained by nuclear techniques are used. Total body nitrogen, calcium, and chlorine were obtained by total body neutron activation. Total body chlorine was used to estimate extracellular water, and total body calcium to determine bone mineral and extracellular solids. Total body potassium was measured by whole body counting to obtain the body cell mass. In addition, total body water was measured by the tritium dilution technique. It was found that either model can be used equally well to measure total body fat in normal subjects. Estimation of body fat as the difference between body weight and the sum of total body nitrogen (protein), total body water, and bone ash (model 1) appears to have an advantage over model 2, which uses body cell mass, extracellular water, and extracellular solids, particularly for patients with metabolic disorders. This advantage is partly due to the fact that the parameter protein (total body nitrogen) is less affected in metabolic disorders than the more labile total body potassium. The closely correlated results obtained with the two models based on nuclear measurements support the conclusion that these techniques provide reliable measurements of total body fat