Banerjee, Puja; Bagchi, Biman
2016-01-01
Molecular dynamics simulations of aqueous potassium nitrate solution reveal a highly complex rotational dynamics of nitrate ions where, superimposed on the expected continuous Brownian motion, are large amplitude angular jumps that are coupled to and at least partly driven by similar large amplitude jump motions in water molecules which are associated with change in the hydrogen bonded water molecule. These jumps contribute significantly to rotational and translational motions of these ions. We explore the detailed mechanism of these correlated (or, coupled) jumps and introduce a new time correlation function to decompose the coupled orientational- jump dynamics of solvent and solute in the aqueous electrolytic solution. Time correlation function provides for the unequivocal determination of the time constant involved in orientational dynamics originating from making and breaking of hydrogen bonds. We discover two distinct mechanisms-both are coupled to density fluctuation but are of different types.
Kleiner, Isabelle; Hougen, Jon T
2015-10-29
A new hybrid-model fitting program for methylamine-like molecules has been developed, on the basis of an effective Hamiltonian in which the ammonia-like inversion motion is treated using a tunneling formalism, whereas the internal-rotation motion is treated using an explicit kinetic energy operator and potential energy function. The Hamiltonian in the computer program is set up as a 2 × 2 partitioned matrix, where each diagonal block contains a traditional torsion-rotation Hamiltonian (as in the earlier program BELGI), and the two off-diagonal blocks contain tunneling terms. This hybrid formulation permits the use of the permutation-inversion group G6 (isomorphic to C(3v)) for terms in the two diagonal blocks but requires G12 for terms in the off-diagonal blocks. The first application of the new program is to 2-methylmalonaldehyde. Microwave data for this molecule were previously fit using an all-tunneling Hamiltonian formalism to treat both large-amplitude motions. For 2-methylmalonaldehyde, the hybrid program achieves the same quality of fit as was obtained with the all-tunneling program, but fits with the hybrid program eliminate a large discrepancy between internal rotation barriers in the OH and OD isotopologs of 2-methylmalonaldehyde that arose in fits with the all-tunneling program. This large isotopic shift in internal rotation barrier is thus almost certainly an artifact of the all-tunneling model. Other molecules for application of the hybrid program are mentioned. PMID:26439709
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
Finite amplitude dynamic motion of viscoelastic materials.
Yen, H.-C.; Mcintire, L. V.
1972-01-01
It is shown that an integral constitutive relation containing a memory function depending on strain tensor invariants can describe the rheological behavior of finite amplitude oscillatory motion of polymer solutions both qualitatively and quantitatively. Values of the material constants are obtained by a numerical technique of simultaneously curve fitting simple shearing viscosity, first normal stress difference, and small amplitude oscillatory motion data.
Constraining Ceres' interior from its Rotational Motion
Rambaux, Nicolas; Dehant, Véronique; Kuchynka, Petr
2011-01-01
Context. Ceres is the most massive body of the asteroid belt and contains about 25 wt.% (weight percent) of water. Understanding its thermal evolution and assessing its current state are major goals of the Dawn Mission. Constraints on internal structure can be inferred from various observations. Especially, detailed knowledge of the rotational motion can help constrain the mass distribution inside the body, which in turn can lead to information on its geophysical history. Aims. We investigate the signature of the interior on the rotational motion of Ceres and discuss possible future measurements performed by the spacecraft Dawn that will help to constrain Ceres' internal structure. Methods. We compute the polar motion, precession-nutation, and length-of-day variations. We estimate the amplitudes of the rigid and non-rigid response for these various motions for models of Ceres interior constrained by recent shape data and surface properties. Results. As a general result, the amplitudes of oscillations in the r...
Rotational Brownian Motion on Sphere Surface and Rotational Relaxation
Ekrem Aydner
2006-01-01
The spatial components of the autocorrelation function of noninteracting dipoles are analytically obtained in terms of rotational Brownian motion on the surface of a unit sphere using multi-level jumping formalism based on Debye's rotational relaxation model, and the rotational relaxation functions are evaluated.
Rotational motion control of a spacecraft
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...
Rotational Motion Control of a Spacecraft
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...
An Exercise in Rotational Motion.
Mahoney, Brother James
1980-01-01
Describes an advanced high school physics experiment demonstrating rotational kinematics and dynamics, using simple equipment such as empty coffee cans, inclined planes, meter sticks, and a large 10-second demonstration timer. (CS)
Rotational motion of Foton M-4
Abrashkin, V. I.; Voronov, K. E.; Piyakov, I. V.; Puzin, Yu. Ya.; Sazonov, V. V.; Semkin, N. D.; Chebukov, S. Yu.
2016-07-01
The actual controlled rotational motion of the Foton M-4 satellite is reconstructed for the mode of single-axis solar orientation. The reconstruction was carried out using data of onboard measurements of vectors of angular velocity and the strength of the Earth's magnetic field. The reconstruction method is based on the reconstruction of the kinematic equations of the rotational motion of a solid body. According to the method, measurement data of both types collected at a certain time interval are processed together. Measurements of the angular velocity are interpolated by piecewise-linear functions, which are substituted in kinematic differential equations for a quaternion that defines the transition from the satellite instrument coordinate system to the inertial coordinate system. The obtained equations represent the kinematic model of the satellite rotational motion. A solution of these equations that approximates the actual motion is derived from the condition of the best (in the sense of the least squares method) match between the measurement data of the strength vector of the Earth's magnetic field and its calculated values. The described method makes it possible to reconstruct the actual rotational satellite motion using one solution of kinematic equations over time intervals longer than 10 h. The found reconstructions have been used to calculate the residual microaccelerations.
Dissipation mechanism of the large-amplitude collective motion
A new microscopic origin responsible for the dissipation process of the large-amplitude collective motion is discussed in terms of the dynamics of distribution function in the time-dependent Hartree Fock (TDHF) phase space. With the use of a simple soluble model, the origin is illustrated by numerically solving the master equation in the microscopic theory of nuclear collective dynamics which has been proposed by the present authors aiming at studying the order-to-chaos transitions of the large-amplitude nuclear collective motion. In this framework, collectivity of the system is expressed by a bundle of trajectories in the TDHF phase space and the dissipation process is related to the diffusive property of the bundle of trajectories. It is clarified that the microscopic dynamics responsible for the dissipation process originates from the dynamical fluctuation part of the coupling between the collective (relevant) and intrinsic (irrelevant) degrees of freedom. (author)
Examining Rotational Ground Motion Induced by Tornados
Kessler, Elijah; Dunn, Robert
2016-03-01
Ring lasers are well known for their ability to detect rotation and to serve as replacements for mechanical gyroscopes. The sensitivity of large ring lasers to various forms of ground motion is less familiar. Since ring lasers preferentially measure rotational ground motion and a standard seismograph is designed to measure translational and vertical ground motion, each device responds to different aspects of ground movement. Therefore, the two instruments will be used to explore responses to microseisms, earthquake generated shear waves, and in particular tornado generated ground movement. On April 27, 2014 an EF4 tornado devastated Vilonia, AR a small town ~ 21 km from the Hendrix College ring laser. The proximity of the tornado's path to the ring laser interferometer and to a seismograph located in Vilonia provided the opportunity to examine the response of these instruments to tornadic generated ground motion. Our measurements suggest tornadic weather systems can produce both rotational and lateral ground motion. This contention is supported by an after the fact damage survey which found that the tornado flattened a forest in which trees were uprooted and laid down in a pair of converging arcs with the centerline pointed in the direction of the tornado's path.
Large-amplitude motion in the Suzuki model
The classical and quantum aspects for the analytically solvable one-dimensional pure monopole Suzuki model are studied to clarify the problem of quantization of classical collective motion. A set of nonlinear dynamic equations for a monopole moment of a nucleus are derived from the TDHF equation using the Wigner function moments model. It provides to describe large-amplitude monopole vibrations. The corresponding collective Hamiltonian is constructed and quantized. The anharmonicity of the collective spectra is analyzed in detal
The Dynamics of Large-Amplitude Motion in Energized Molecules
Perry, David S. [Univ. of Akron, OH (United States). Dept. of Chemistry
2016-05-27
Chemical reactions involve large-amplitude nuclear motion along the reaction coordinate that serves to distinguish reactants from products. Some reactions, such as roaming reactions and reactions proceeding through a loose transition state, involve more than one large-amplitude degree of freedom. Because of the limitation of exact quantum nuclear dynamics to small systems, one must, in general, define the active degrees of freedom and separate them in some way from the other degrees of freedom. In this project, we use large-amplitude motion in bound model systems to investigate the coupling of large-amplitude degrees of freedom to other nuclear degrees of freedom. This approach allows us to use the precision and power of high-resolution molecular spectroscopy to probe the specific coupling mechanisms involved, and to apply the associated theoretical tools. In addition to slit-jet spectra at the University of Akron, the current project period has involved collaboration with Michel Herman and Nathalie Vaeck of the Université Libre de Bruxelles, and with Brant Billinghurst at the Canadian Light Source (CLS).
Large amplitude oscillatory motion along a solar filament
Vrsnak, B; Thalmann, J K; Zic, T
2007-01-01
Large amplitude oscillations of solar filaments is a phenomenon known for more than half a century. Recently, a new mode of oscillations, characterized by periodical plasma motions along the filament axis, was discovered. We analyze such an event, recorded on 23 January 2002 in Big Bear Solar Observatory H$\\alpha$ filtergrams, in order to infer the triggering mechanism and the nature of the restoring force. Motion along the filament axis of a distinct buldge-like feature was traced, to quantify the kinematics of the oscillatory motion. The data were fitted by a damped sine function, to estimate the basic parameters of the oscillations. In order to identify the triggering mechanism, morphological changes in the vicinity of the filament were analyzed. The observed oscillations of the plasma along the filament was characterized by an initial displacement of 24 Mm, initial velocity amplitude of 51 km/s, period of 50 min, and damping time of 115 min. We interpret the trigger in terms of poloidal magnetic flux inje...
Attenuation of ground-motion spectral amplitudes in southeastern Australia
Allen, T.I.; Cummins, P.R.; Dhu, T.; Schneider, J.F.
2007-01-01
A dataset comprising some 1200 weak- and strong-motion records from 84 earthquakes is compiled to develop a regional ground-motion model for southeastern Australia (SEA). Events were recorded from 1993 to 2004 and range in size from moment magnitude 2.0 ??? M ??? 4.7. The decay of vertical-component Fourier spectral amplitudes is modeled by trilinear geometrical spreading. The decay of low-frequency spectral amplitudes can be approximated by the coefficient of R-1.3 (where R is hypocentral distance) within 90 km of the seismic source. From approximately 90 to 160 km, we observe a transition zone in which the seismic coda are affected by postcritical reflections from midcrustal and Moho discontinuities. In this hypocentral distance range, geometrical spreading is approximately R+0.1. Beyond 160 km, low-frequency seismic energy attenuates rapidly with source-receiver distance, having a geometrical spreading coefficient of R-1.6. The associated regional seismic-quality factor can be expressed by the polynomial: log Q(f) = 3.66 - 1.44 log f + 0.768 (log f)2 + 0.058 (log f)3 for frequencies 0.78 ??? f ??? 19.9 Hz. Fourier spectral amplitudes, corrected for geometrical spreading and anelastic attenuation, are regressed with M to obtain quadratic source scaling coefficients. Modeled vertical-component displacement spectra fit the observed data well. Amplitude residuals are, on average, relatively small and do not vary with hypocentral distance. Predicted source spectra (i.e., at R = 1 km) are consistent with eastern North American (ENA) Models at low frequencies (f less than approximately 2 Hz) indicating that moment magnitudes calculated for SEA earthquakes are consistent with moment magnitude scales used in ENA over the observed magnitude range. The models presented represent the first spectral ground-motion prediction equations develooed for the southeastern Australian region. This work provides a useful framework for the development of regional ground-motion relations
Amplitude scaling for interchange motions of plasma filaments
Kube, R; Garcia, O E
2016-01-01
We numerically study the interchange motion of seeded plasma blobs in a reduced two-field fluid model. If we neglect the compression of the electric drift in the model, the maximal radial center-of-mass velocity V of the filament follows the familiar square-root scaling V ~ (\\Delta n/N)^1/2, where \\Delta n is the blob amplitude and N is the background density. When including compression of the electric drift to account for an inhomogeneous magnetic field, the numerical simulations reveal that the maximal blob velocity depends linearly on its initial amplitude, V ~ \\Delta n/N. When the relative initial amplitude of the filament exceeds approximately unity we recover the square root velocity scaling. We explain the observed scaling laws in t erms of the conserved energy integrals of the model equations. The compression term leads to a constraint on the maximum kinetic energy of the blob, which is not present if the drift compression is ignored. If the compression term is included, only approximately half of the...
Effect of electric-field fluctuations on rotational revival amplitudes
Pearson, Andrew J.; Antonsen, Thomas M.
2009-11-01
We study numerically the behavior of rotational revivals in a molecular gas when subject to the fluctuating electric field of a background plasma. We model a molecule using a rigid rotor Hamiltonian and couple it to an electric field using permanent and induced multipole interaction terms. The evolution of the density matrix for the molecule is calculated for a short intense laser pulse, followed by a fluctuating background electric field. A broad superposition of angular momentum eigenstates of a molecule is created by the laser field, and the result of an ensemble average over initial molecular orientation is a set of recurring peaks in the probability density for observing a particular orientation—the so-called “rotational revivals.” The fluctuating background field is created using the dressed particle technique, and the result is a loss of coherence between the phases of the various basis states of the molecule, which causes a decreasing amplitude for subsequent alignment peaks. Modern short-pulse lasers operate with sufficient intensity to make this effect relevant to experiments in molecular alignment.
Remapping motion across modalities: tactile rotations influence visual motion judgments.
Butz, Martin V; Thomaschke, Roland; Linhardt, Matthias J; Herbort, Oliver
2010-11-01
Multisensory interactions between haptics and vision remain poorly understood. Previous studies have shown that shapes, such as letters of the alphabet, when drawn on the skin, are differently perceived dependent upon which body part is stimulated and on how the stimulated body part, such as the hand, is positioned. Another line of research within this area has investigated multisensory interactions. Tactile perceptions, for example, have the potential to disambiguate visually perceived information. While the former studies focused on explicit reports about tactile perception, the latter studies relied on fully aligned multisensory stimulus dimensions. In this study, we investigated to what extent rotating tactile stimulations on the hand affect directional visual motion judgments implicitly and without any spatial stimulus alignment. We show that directional tactile cues and ambiguous visual motion cues are integrated, thus biasing the judgment of visually perceived motion. We further show that the direction of the tactile influence depends on the position and orientation of the stimulated part of the hand relative to a head-centered frame of reference. Finally, we also show that the time course of the cue integration is very versatile. Overall, the results imply immediate directional cue integration within a head-centered frame of reference. PMID:20878396
MEMS Rotational Electret Energy Harvester for Human Motion
Nakano, J.; Komori, K.; Hattori, Y.; Suzuki, Y.
2015-12-01
This paper reports the development of MEMS rotational electret energy harvester (EH) for capturing kinetic energy of human motion. Optimal design method of rotational electret EH is proposed by considering both the rate of overlapping-area-change and the parasitic capacitance. A rotational MEMS electret EH with embedded ball bearing has been successfully developed. Up to 3.6 μW has been obtained at 1 rps rotation with an early prototype.
Fourier Amplitudes of the Foundation Motion connected with Soil-Structure Interaction
Hayir, Abdul; Gicev, Vlado
2009-01-01
The main objective of this study is to understand the phenomena connected with the interaction and to give directions for improvement of the design of the earthquake resistant structures. Fourier amplitudes (amplitudes versus frequencies) of the foundation motion connected with the soil-structure interaction and differential motions of the foundation-structure contact due to the wave passage are considered. We expect that the motion of the flexible foundation will be larger tha...
Action induction by visual perception of rotational motion.
Classen, Claudia; Kibele, Armin
2016-09-01
A basic process in the planning of everyday actions involves the integration of visually perceived movement characteristics. Such processes of information integration often occur automatically. The aim of the present study was to examine whether the visual perception of spatial characteristics of a rotational motion (rotation direction) can induce a spatially compatible action. Four reaction time experiments were conducted to analyze the effect of perceiving task irrelevant rotational motions of simple geometric figures as well as of gymnasts on a horizontal bar while responding to color changes in these objects. The results show that the participants react faster when the directional information of a rotational motion is compatible with the spatial characteristics of an intended action. The degree of complexity of the perceived event does not play a role in this effect. The spatial features of the used biological motion were salient enough to elicit a motion based Simon effect. However, in the cognitive processing of the visual stimulus, the critical criterion is not the direction of rotation, but rather the relative direction of motion (direction of motion above or below the center of rotation). Nevertheless, this conclusion is tainted with reservations since it is only fully supported by the response behavior of female participants. PMID:26259847
Phase lock and rotational motion of a parametric pendulum
Litak, Grzegorz; Borowiec,Marek; Wiercigroch , Marian
2006-01-01
The effect of noise on a rotational mode of a pendulum excited kinematically in vertical direction has been analyzed. We have shown that for a weak noise transitions from oscillations to rotations and vice versa are possible. For a moderate noise level dynamics of the system is governed by a combination of the excitation amplitude and stochastic component. Consequently for stronger noise the rotational solution as an independent sychonized mode has vanished.
Quantal rotation and its coupling to intrinsic motion in nuclei
Nakatsukasa, Takashi; Matsuzaki, Masayuki; Shimizu, Yoshifumi R
2016-01-01
Symmetry breaking is an importance concept in nuclear physics and other fields of physics. Self-consistent coupling between the mean-field potential and the single-particle motion is a key ingredient in the unified model of Bohr and Mottelson, which could lead to a deformed nucleus as a consequence of spontaneous breaking of the rotational symmetry. Some remarks on the finite-size quantum effects are given. In finite nuclei, the deformation inevitably introduces the rotation as a symmetry-restoring collective motion (Anderson-Nambu-Goldstone mode), and the rotation affects the intrinsic motion. In order to investigate the interplay between the rotational and intrinsic motions in a variety of collective phenomena, we use the cranking prescription together with the quasiparticle random phase approximation. At low spin, the coupling effect can be seen in the generalized intensity relation. A feasible quantization of the cranking model is presented, which provides a microscopic approach to the higher-order intens...
Precise Measurement of Velocity Dependent Friction in Rotational Motion
Alam, Junaid; Hassan, Hafsa; Shamim, Sohaib; Mahmood, Waqas; Anwar, Muhammad Sabieh
2011-01-01
Frictional losses are experimentally determined for a uniform circular disc exhibiting rotational motion. The clockwise and anticlockwise rotations of the disc, that result when a hanger tied to a thread is released from a certain height, give rise to vertical oscillations of the hanger as the thread winds and unwinds over a pulley attached to the…
Change of amplitude of motion and force of hand for women after a radical mammectomy
Odinec T.E.
2009-01-01
The estimation of dynamometer of brush and amplitude of motion is rotined in a humeral joint for women. The features of remote postprocess period are considered after a radical mammectomy. Close correlation is rotined between amplitude of motion and index of function of the external breathing. The results of goniometer and dynamometer are presented. A hydrokinesitherapy is considered from position of perspective mean of rehabilitation of the functional state of women. The high degree of inter...
Strong-motion fluid rotation seismograph
Jedlička, Petr; Buben, Jiří; Kozák, Jan
2009-01-01
Roč. 99, 2B (2009), s. 1443-1448. ISSN 0037-1106 Institutional research plan: CEZ:AV0Z30120515; CEZ:AV0Z30130516 Keywords : rotation seismograph * seismic waves * fluid seismometer Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.860, year: 2009
Reconstruction of spacecraft rotational motion using a Kalman filter
Pankratov, V. A.; Sazonov, V. V.
2016-05-01
Quasi-static microaccelerations of four satellites of the Foton series (nos. 11, 12, M-2, M-3) were monitored as follows. First, according to measurements of onboard sensors obtained in a certain time interval, spacecraft rotational motion was reconstructed in this interval. Then, along the found motion, microacceleration at a given onboard point was calculated according to the known formula as a function of time. The motion was reconstructed by the least squares method using the solutions to the equations of satellite rotational motion. The time intervals in which these equations make reconstruction possible were from one to five orbital revolutions. This length is increased with the modulus of the satellite angular velocity. To get an idea on microaccelerations and satellite motion during an entire flight, the motion was reconstructed in several tens of such intervals. This paper proposes a method for motion reconstruction suitable for an interval of arbitrary length. The method is based on the Kalman filter. We preliminary describe a new version of the method for reconstructing uncontrolled satellite rotational motion from magnetic measurements using the least squares method, which is essentially used to construct the Kalman filter. The results of comparison of both methods are presented using the data obtained on a flight of the Foton M-3.
Large amplitude motion with a stochastic mean-field approach
Yilmaz Bulent
2012-12-01
Full Text Available In the stochastic mean-field approach, an ensemble of initial conditions is considered to incorporate correlations beyond the mean-field. Then each starting point is propagated separately using the Time-Dependent Hartree-Fock equation of motion. This approach provides a rather simple tool to better describe fluctuations compared to the standard TDHF. Several illustrations are presented showing that this theory can be rather effective to treat the dynamics close to a quantum phase transition. Applications to fusion and transfer reactions demonstrate the great improvement in the description of mass dispersion.
Quantal rotation and its coupling to intrinsic motion in nuclei
Nakatsukasa, Takashi; Matsuyanagi, Kenichi; Matsuzaki, Masayuki; Shimizu, Yoshifumi R.
2016-07-01
Symmetry breaking is an important concept in nuclear physics and other fields of physics. Self-consistent coupling between the mean-field potential and the single-particle motion is a key ingredient in the unified model of Bohr and Mottelson, which could lead to a deformed nucleus as a consequence of spontaneous breaking of the rotational symmetry. Some remarks on the finite-size quantum effects are given. In finite nuclei, the deformation inevitably introduces the rotation as a symmetry-restoring collective motion (Anderson–Nambu–Goldstone mode), and the rotation affects the intrinsic motion. In order to investigate the interplay between the rotational and intrinsic motions in a variety of collective phenomena, we use the cranking prescription together with the quasiparticle random phase approximation (QRPA). At low spin, the coupling effect can be seen in the generalized intensity relation. A feasible quantization of the cranking model is presented, which provides a microscopic approach to the higher-order intensity relation. At high spin, the semiclassical cranking prescription works well. We discuss properties of collective vibrational motions under rapid rotation and/or large deformation. The superdeformed shell structure plays a key role in emergence of a new soft mode which could lead to instability toward the {K}π ={1}- octupole shape. A wobbling mode of excitation, which is a clear signature of the triaxiality, is discussed in terms of a microscopic point of view. A crucial role played by the quasiparticle alignment is presented.
Rotational motion of traveling spots in dissipative systems.
Teramoto, Takashi; Suzuki, Katsuya; Nishiura, Yasumasa
2009-10-01
What is the origin of rotational motion? An answer is presented through the study of the dynamics for spatially localized spots near codimension 2 singularity consisting of drift and peanut instabilities. The drift instability causes a head-tail asymmetry in spot shape, and the peanut one implies a deformation from circular to peanut shape. Rotational motion of spots can be produced by combining these instabilities in a class of three-component reaction-diffusion systems. Partial differential equations dynamics can be reduced to a finite-dimensional one by projecting it to slow modes. Such a reduction clarifies the bifurcational origin of rotational motion of traveling spots in two dimensions in close analogy to the normal form of 1:2 mode interactions. PMID:19905416
Precise measurement of velocity dependent friction in rotational motion
Frictional losses are experimentally determined for a uniform circular disc exhibiting rotational motion. The clockwise and anticlockwise rotations of the disc, that result when a hanger tied to a thread is released from a certain height, give rise to vertical oscillations of the hanger as the thread winds and unwinds over a pulley attached to the disc. It is thus observed how the maximum height is achieved by the hanger decrements in every bounce. From the decrements, the rotational frictional losses are measured. The precision is enhanced by correlating vertical motion with the angular motion. This method leads to a substantial improvement in precision. Furthermore, the frictional torque is shown to be proportional to the angular speed. The experiment has been successfully employed in the undergraduate lab setting.
Motions of objects with magnetizable materials along a horizontal plane in a rotating magnetic field
The motions of objects with magnetizable materials in a viscous non-magnetic fluid near a horizontal bottom of a vessel in an uniform applied rotating magnetic field are examined experimentally. The objects rotate in the same direction as the field and have a translational velocity along the bottom. Two types of objects, prolate bodies with a magnetizable polymer and magnetic fluid droplets, are studied. Dependencies of an average translational velocity of bodies and droplets on the field frequency for different field amplitudes and other parameters are obtained. The velocity direction dependence on the field frequency is found only for magnetic fluid droplets. - Highlights: • Magnetizable objects in a rotating magnetic field are examined experimentally. • Magnetizable polymer bodies and magnetic fluid droplets are studied. • Objects rotate with the field and have translational velocity along the bottom. • Nonmonotonic velocity dependencies on the field frequency are obtained. • Change of droplets velocity direction at some field frequency is found
Liang Yonggang; Liu Tiebing; Liu Hongxing; Si Junfeng; Huang Xiaolin; Wang Rui
2013-01-01
Classical Amplitude Spectrum analysis and Full Amplitude Spectrum analysis exhibit deficiencies in analyzing the two perpendicular directional vibration displacement signals of a rotating rotor. The shape of Classical Amplitude Spectrum is influenced by the installing position of its sensor. Neither Classical Amplitude Spectrum nor Full Amplitude Spectrum can indicate the actual radial rotor vibration amplitude on every frequency. Therefore, the previous two methods are not convenient to be u...
RW Per - Nodal motion changes its amplitude by 1.4 mag
Schaefer, Bradley E.; Fried, Robert E.
1991-01-01
RW Per was found to have large secular changes in its eclipse amplitude. In blue light, for example, the amplitude was 3.2 mag in the early 1900s, 2.2 mag in the late 1960s, and 1.75 mag in 1990. Throughout this time, the brightness at maximum was constant in all colors. It is shown that the only possible explanation is nodal motion, where the inclination varies with a period of roughly 100,000 yr. The nodal motion is caused by a third star, for which the light curve, the colors, and the O - C curve already provide evidence. Thus, RW Per is only the fourth known star with large changes of eclipse amplitude and is only the second example of nodal motion.
The Double Rotation as Invariant of Motion in Quantum Mechanics
Zeps, Dainis
2010-01-01
Quantum mechanics may loose its weirdness if systematically geometric algebra methods would be used more and more. Crucial aspect is to find laws of quantum mechanics be present in macroworld in form of description of motions rather than objects. To help to reach this goal we suggest to use double rotation as one of base invariants in quantum mechanics.
New portable sensor system for rotational seismic motion measurements
A new mechanical sensor system for recording the rotation of ground velocity has been constructed. It is based on measurements of differential motions between paired sensors mounted along the perimeter of a rigid (undeformable) disk. The elementary sensors creating the pairs are sensitive low-frequency geophones currently used in seismic exploration to record translational motions. The main features of the new rotational seismic sensor system are flat characteristics in the wide frequency range from 1 to 200 Hz and sensitivity limit of the order of 10-8 rad/s. Notable advantages are small dimensions, portability, easy installation and operation in the field, and the possibility of calibrating the geophones in situ simultaneously with the measurement. An important feature of the instrument is that it provides records of translational seismic motions together with rotations, which allows many important seismological applications. We have used the new sensor system to record the vertical rotation velocity due to a small earthquake of ML=2.2, which occurred within the earthquake swarm in Western Bohemia in autumn 2008. We found good agreement of the rotation record with the transverse acceleration as predicted by theory. This measurement demonstrates that this device has a much wider application than just to prospecting measurements, for which it was originally designed.
Change of amplitude of motion and force of hand for women after a radical mammectomy
Odinec T.E.
2009-12-01
Full Text Available The estimation of dynamometer of brush and amplitude of motion is rotined in a humeral joint for women. The features of remote postprocess period are considered after a radical mammectomy. Close correlation is rotined between amplitude of motion and index of function of the external breathing. The results of goniometer and dynamometer are presented. A hydrokinesitherapy is considered from position of perspective mean of rehabilitation of the functional state of women. The high degree of intercommunication is rotined between taking and bending in a humeral joint the vital capacity of lights.
The adiabatic motion of charged dust grains in rotating magnetospheres
Northrop, T. G.; Hill, J. R.
1983-01-01
Adiabatic equations of motion are derived for the micrometer-sized dust grains detected in the Jovian and Saturn magnetospheres by the Pioneer 10 and 11 spacecraft. The adiabatic theory of charged particle motion is extended to the case of variable grain charge. Attention is focused on the innermost and outermost limits to the grain orbit evolution, with all orbits tending to become circular with time. The parameters such as the center equation of motion, the drift velocity, and the parallel equation of motion are obtained for grains in a rotating magnetosphere. Consideration is given to the effects of periodic grain charge-discharge, which are affected by the ambient plasma properties and the grain plasma velocity. The charge-discharge process at the gyrofrequency is determined to eliminate the invariance of the magnetic moment and cause the grain to exhibit radial movement. The magnetic moment increases or decreases as a function of the gyrophase of the charge variation.
Origin of inertia in large-amplitude collective motion in ﬁnite Fermi systems
Sudhir R Jain
2012-02-01
We argue that mass parameters appearing in the treatment of large-amplitude collective motion, be it ﬁssion or heavy-ion reactions, originate as a consequence of their relation with Lyapunov exponents coming from the classical dynamics, and, fractal dimension associated with diffusive modes coming from hydrodynamic description.
Holographic Brownian Motion in Two Dimensional Rotating Fluid
Atmaja, Ardian Nata
2012-01-01
The Brownian motion of a heavy quark under a rotating plasma corresponds to BTZ black hole is studied using holographic method from string theory. The heavy quark represented as the end of string at the boundary of BTZ black hole and the corresponding rotating plasma is two dimensional spacetime. The string fluctuation requires the angular velocity to be equal to the ratio between inner horizon and outer horizon, known as terminal velocity and also related to the zero total force condition. With this angular velocity, the string fluctuation solution has oscillatory modes in time and radial coordinates. We show the displacement square of this solution behaves as a Brownian particle in non-relativistic limit. For relativistic case, we argue that it is more appropriate to compute just the the leading order of low frequency limit of random-random force correlator. The Brownian motion relates this correlator with physical observables: mass of Brownian particle, friction coefficient and temperature of the plasma.
1976-01-01
The two-particle, steady-state Schroedinger equation is transformed to center of mass and internuclear distance vector coordinates, leading to the free particle wave equation for the kinetic energy motion of the molecule and a decoupled wave equation for a single particle of reduced mass moving in a spherical potential field. The latter describes the vibrational and rotational energy modes of the diatomic molecule. For fixed internuclear distance, this becomes the equation of rigid rotator motion. The classical partition function for the rotator is derived and compared with the quantum expression. Molecular symmetry effects are developed from the generalized Pauli principle that the steady-state wave function of any system of fundamental particles must be antisymmetric. Nuclear spin and spin quantum functions are introduced and ortho- and para-states of rotators, along with their degeneracies, are defined. Effects of nuclear spin on entropy are deduced. Next, rigid polyatomic rotators are considered and the partition function for this case is derived. The patterns of rotational energy levels for nonlinear molecules are discussed for the spherical symmetric top, for the prolate symmetric top, for the oblate symmetric top, and for the asymmetric top. Finally, the equilibrium energy and specific heat of rigid rotators are derived.
Fast Drug Release Using Rotational Motion of Magnetic Gel Beads
Jun-Ichi Takimoto
2008-03-01
Full Text Available Accelerated drug release has been achieved by means of the fast rotation of magnetic gel beads. The magnetic gel bead consists of sodium alginate crosslinked by calcium chlorides, which contains barium ferrite of ferrimagnetic particles, and ketoprofen as a drug. The bead underwent rotational motion in response to rotational magnetic fields. In the case of bead without rotation, the amount of drug release into a phosphate buffer solution obeyed non-Fickian diffusion. The spontaneous drug release reached a saturation value of 0.90Ã¢Â€Â‰mg at 25 minutes, which corresponds to 92% of the perfect release. The drug release was accelerated with increasing the rotation speed. The shortest time achieving the perfect release was approximately 3 minutes, which corresponds to 1/8 of the case without rotation. Simultaneous with the fast release, the bead collapsed probably due to the strong water flow surrounding the bead. The beads with high elasticity were hard to collapse and the fast release was not observed. Hence, the fast release of ketoprofen is triggered by the collapse of beads. Photographs of the collapse of beads, time profiles of the drug release, and a pulsatile release modulated by magnetic fields were presented.
Diffusion of hydrocarbons in confined media: Translational and rotational motion
S Y Bhide; A V Anil Kumar; S Yashonath
2001-10-01
Diffusion of monatomic guest species within confined media has been understood to a good degree due to investigations carried out during the past decade and a half. Most guest species that are of industrial relevance are actually polyatomics such as, for example, hydrocarbons in zeolites. We attempt to investigate the influence of non-spherical nature of guest species on diffusion. Recent molecular dynamics (MD) simulations of motion of methane in NaCaA and NaY, benzene in NaY and one-dimensional channels AlPO4-5, VPI-5 and carbon nanotube indicate interesting insights into the influence of the host on rotational degrees of freedom and rientational properties. It is shown that benzene in one-dimensional channels where the levitation parameter is near unity exhibits translational motion opposite to what is expected on the basis of molecular anisotropy. Rotational motion of benzene also possesses rotational diffusivities around 6 and 2 axes opposite to what is expected on the basis of molecular geometry. Methane shows orientational preference for 2 + 2 or 1 + 3 depending on the magnitude of the levitation parameter.
Low-amplitude rotational modulation rather than pulsations in the CoRoT B-type supergiant HD 46769
Aerts, C; Catala, C; Neiner, C; Briquet, M; Castro, N; Schmid, V S; Scardia, M; Rainer, M; Poretti, E; Papics, I; Degroote, P; Bloemen, S; Oestensen, R H; Auvergne, M; Baglin, A; Baudin, F; Michel, E; Samadi, R
2013-01-01
{We aim to detect and interpret photometric and spectroscopic variability of the bright CoRoT B-type supergiant target HD\\,46769 ($V=5.79$). We also attempt to detect a magnetic field in the target.} {We analyse a 23-day oversampled CoRoT light curve after detrending, as well as spectroscopic follow-up data, by using standard Fourier analysis and Phase Dispersion Minimization methods. We determine the fundamental parameters of the star, as well as its abundances from the most prominent spectral lines. We perform a Monte Carlo analysis of spectropolarimetric data to obtain an upper limit of the polar magnetic field, assumping a dipole field.} {In the CoRoT data, we detect a dominant period of 4.84\\,d with an amplitude of 87\\,ppm, and some of its (sub-)multiples. Given the shape of the phase-folded light curve and the absence of binary motion, we interpret the dominant variability in terms of rotational modulation, with a rotation period of 9.69\\,d. Subtraction of the rotational modulation signal does not revea...
Quantum theory of dynamical collective subspace for large-amplitude collective motion
By placing emphasis on conceptual correspondence to the ''classical'' theory which has been developed within the framework of the time-dependent Hartree-Fock theory, a full quantum theory appropriate for describing large-amplitude collective motion is proposed. A central problem of the quantum theory is how to determine an optimal representation called a dynamical representation; the representation is specific for the collective subspace where the large-amplitude collective motion is replicated as satisfactorily as possible. As an extension of the classical theory where the concept of an approximate integral surface plays an important role, the dynamical representation is properly characterized by introducing a concept of an approximate invariant subspace of the Hamiltonian. (author)
Adiabatic motion of charged dust grains in rotating magnetospheres
Dust grains in the ring systems and rapidly rotating magnetospheres of the outer planets such as Jupiter and Saturn may be sufficiently charged that the magnetic and electric forces on them are comparable with the gravitational force. The adiabatic theory of charged particle motion has previously been applied to electrons and atomic size particles. But it is also applicable to these charged dust grains in the micrometer and smaller size range. We derive here the guiding center equation of motion, drift velocity, and parallel equation of motion for these grains in a rotating magnetosphere. The effects of periodic grain charge-discharge have not been treated previously and have been included in this analysis. Grain charge is affected by the surrounding plasma properties and by the grain plasma velocity (among other factors), both of which may vary over the gyrocircle. The resulting charge-discharge process at the gyrofrequency destroys the invariance of the magnetic moment and causes a grain to move radially. The magnetic moment may increase or decrease, depending on the gyrophase of the charge variation. If it decreases, the motion is always toward synchronous radius for an equatorial grain. But the orbit becomes circular before the grain reaches synchronous radius, a conclusion that follows from an exact constant of the motion. This circularization can be viewed as a consequence of the gradual reduction in the magnetic moment. This circularization also suggests that dust grains leaving Io could not reach the region of the Jovian ring, but several effects could change that conclusion. Excellent qualitative and quantitative agreement is obtained between adiabatic theory and detailed numerical orbit integrations
Extraction of dynamical collective subspace for large-amplitude collective motion
A quantum theory appropriate for describing global aspects of nuclear collectivity is applied to a simple four-level system with pairing interaction. One of the basic ingredients of the theory is how to select a dynamical representation specific for large-amplitude collective motion under consideration out of an infinite number of unitary-equivalent representations. Physical meaning of dynamical collective subspace associated with the dynamical representation is elucidated by using the simple model Hamiltonian. (author)
Local computation of angular velocity in rotational visual motion.
Barraza, José F; Grzywacz, Norberto M
2003-07-01
Retinal images evolve continuously over time owing to self-motions and to movements in the world. Such an evolving image, also known as optic flow, if arising from natural scenes can be locally decomposed in a Bayesian manner into several elementary components, including translation, expansion, and rotation. To take advantage of this decomposition, the brain has neurons tuned to these types of motions. However, these neurons typically have large receptive fields, often spanning tens of degrees of visual angle. Can neurons such as these compute elementary optic-flow components sufficiently locally to achieve a reasonable decomposition? We show that human discrimination of angular velocity is local. Local discrimination of angular velocity requires an accurate estimation of the center of rotation within the optic-flow field. Inaccuracies in estimating the center of rotation result in a predictable systematic error when one is estimating local angular velocity. Our results show that humans make the predicted errors. We discuss how the brain might estimate the elementary components of the optic flow locally by using large receptive fields. PMID:12868642
Effects of Rotational Motion in Robotic Needle Insertion
Ramezanpour, H.; Yousefi, H.; Rezaei, M.; Rostami, M.
2015-01-01
Background Robotic needle insertion in biological tissues has been known as one the most applicable procedures in sampling, robotic injection and different medical therapies and operations. Objective In this paper, we would like to investigate the effects of angular velocity in soft tissue insertion procedure by considering force-displacement diagram. Non-homogenous camel liver can be exploited as a tissue sample under standard compression test with Zwick/Roell device employing 1-D axial load-cell. Methods Effects of rotational motion were studied by running needle insertion experiments in 5, 50 and 200 mm/min in two types of with or without rotational velocity of 50, 150 and 300 rpm. On further steps with deeper penetrations, friction force of the insertion procedure in needle shaft was acquired by a definite thickness of the tissue. Results Designed mechanism of fixture for providing different frequencies of rotational motion is available in this work. Results for comparison of different force graphs were also provided. Conclusion Derived force-displacement graphs showed a significant difference between two procedures; however, tissue bleeding and disorganized micro-structure would be among unavoidable results. PMID:26688800
Stabilization of rotational motion with application to spacecraft attitude control
Wisniewski, Rafal
2000-01-01
force. It is shown that this control law makes the system uniformly asymptotically stable to the desired reference point. The concepet is very straightforward in the Euclidean space however a global rotation control cannot be tackled.An additional modification is made to address a system which flow lies...... for global stabilization of a rotary motion. Along with a model of the system formulated in the Hamilton's canonical from the algorithm uses information about a required potential energy and a dissipation term. The control action is the sum of the gradient of the potential energy and the dissipation...
Stabilization of rotational motion with application to spacecraft attitude control
Wisniewski, Rafal
2001-01-01
force. It is shown that this control law makes the system uniformly asymptotically stable to the desired reference point. The concepet is very straightforward in the Euclidean space however a global rotation control cannot be tackled.An additional modification is made to address a system which flow lies...... for global stabilization of a rotary motion. Along with a model of the system formulated in the Hamilton's canonical from the algorithm uses information about a required potential energy and a dissipation term. The control action is the sum of the gradient of the potential energy and the dissipation...
Vibrational motions in rotating nuclei studied by Coulomb excitations
Shimizu, Yoshifumi R. [Kyushu Univ., Fukuoka (Japan). Dept. of Physics
1998-03-01
As is well-known Coulomb excitation is an excellent tool to study the nuclear collective motions. Especially the vibrational excitations in rotating nuclei, which are rather difficult to access by usual heavy-ion fusion reactions, can be investigated in detail. Combined with the famous 8{pi}-Spectrometer, which was one of the best {gamma}-ray detector and had discovered some of superdeformed bands, such Coulomb excitation experiments had been carried out at Chalk River laboratory just before it`s shutdown of physics division. In this meeting some of the experimental data are presented and compared with the results of theoretical investigations. (author)
Rheological Transition of Sheared Frictionless Disks with Rotational Motion
Olsson, Peter; Teitel, Steve
We consider the massive Durian bubble model for sheared bidisperse disks, but modified so as to include the rotational motion of particles due to dissipative collisional torques. In such a model, particles possess a viscous tangential dissipation, though no elastic tangential friction. As the packing fraction is increased, we find a discontinuous transition from Bagnoldian to Newtonian rheology, at a packing fraction that lies below the jamming transition. At this transition we find a region of coexisting shear bands of Bagnoldian and Newtonian rheology, and suggestions of discontinuous shear thickening upon increasing the shear strain rate. This work has been supported by NSF Grant No. DMR-1205800.
Brownian Motion and Harmonic Functions on Rotationally Symmetric Manifolds
March, Peter
1986-01-01
We consider Brownian motion $X$ on a rotationally symmetric manifold $M_g = (\\mathbb{R}^n, ds^2), ds^2 = dr^2 + g(r)^2 d\\theta^2$. An integral test is presented which gives a necessary and sufficient condition for the nontriviality of the invariant $\\sigma$-field of $X$, hence for the existence of nonconstant bounded harmonic functions on $M_g$. Conditions on the sectional curvatures are given which imply the convergence or the divergence of the test integral.
Experimental Motion Analysis of Radially Rotating Beams Using High-Speed Camera and Motion Analyzer
Low, K. H.; Michael W.S. Lau; Low, K.K.
1996-01-01
Although strain gauges can be attached to a system for vibration analysis, wires connected to the strain gauges may disturb the system and affect the accuracy of the strain measurement. As an alternative, this work presents the use of a high-speed camera combined with a motion analyzer to study the motion of rotating flexible beams. One end of the beam is rigidly connected to a motor, while the other end is free. White stickers placed on selected points on a given beam are the reference point...
Biological Nanomotors with a Revolution, Linear, or Rotation Motion Mechanism.
Guo, Peixuan; Noji, Hiroyuki; Yengo, Christopher M; Zhao, Zhengyi; Grainge, Ian
2016-03-01
The ubiquitous biological nanomotors were classified into two categories in the past: linear and rotation motors. In 2013, a third type of biomotor, revolution without rotation (http://rnanano.osu.edu/movie.html), was discovered and found to be widespread among bacteria, eukaryotic viruses, and double-stranded DNA (dsDNA) bacteriophages. This review focuses on recent findings about various aspects of motors, including chirality, stoichiometry, channel size, entropy, conformational change, and energy usage rate, in a variety of well-studied motors, including FoF1 ATPase, helicases, viral dsDNA-packaging motors, bacterial chromosome translocases, myosin, kinesin, and dynein. In particular, dsDNA translocases are used to illustrate how these features relate to the motion mechanism and how nature elegantly evolved a revolution mechanism to avoid coiling and tangling during lengthy dsDNA genome transportation in cell division. Motor chirality and channel size are two factors that distinguish rotation motors from revolution motors. Rotation motors use right-handed channels to drive the right-handed dsDNA, similar to the way a nut drives the bolt with threads in same orientation; revolution motors use left-handed motor channels to revolve the right-handed dsDNA. Rotation motors use small channels (3 nm) with room for the bolt to revolve. Binding and hydrolysis of ATP are linked to different conformational entropy changes in the motor that lead to altered affinity for the substrate and allow work to be done, for example, helicase unwinding of DNA or translocase directional movement of DNA. PMID:26819321
The exact equation of motion of a simple pendulum of arbitrary amplitude: a hypergeometric approach
The motion of a simple pendulum of arbitrary amplitude is usually treated by approximate methods. By using generalized hypergeometric functions, it is however possible to solve the problem exactly. In this paper, we provide the exact equation of motion of a simple pendulum of arbitrary amplitude. A new and exact expression for the time of swinging of a simple pendulum from the vertical position to an arbitrary angular position θ is given by equation (3.10). The time period of such a pendulum is also exactly expressible in terms of hypergeometric functions. The exact expressions thus obtained are used to plot the graphs that compare the exact time period T(θ0) with the time period T(0) (based on simple harmonic approximation). We also compare the relative difference between T(0) and T(θ0) found from the exact equation of motion with the usual perturbation theory estimate. The treatment is intended for graduate students, who have acquired some familiarity with the hypergeometric functions. This approach may also be profitably used by specialists who encounter during their investigations nonlinear differential equations similar in form to the pendulum equation. Such nonlinear differential equations could arise in diverse fields, such as acoustic vibrations, oscillations in small molecules, turbulence and electronic filters, among others.
Experimental Motion Analysis of Radially Rotating Beams Using High-Speed Camera and Motion Analyzer
K.H. Low
1996-01-01
Full Text Available Although strain gauges can be attached to a system for vibration analysis, wires connected to the strain gauges may disturb the system and affect the accuracy of the strain measurement. As an alternative, this work presents the use of a high-speed camera combined with a motion analyzer to study the motion of rotating flexible beams. One end of the beam is rigidly connected to a motor, while the other end is free. White stickers placed on selected points on a given beam are the reference points in a digitization process. The modes of the vibrating beams can be filmed and analyzed. The vibration parameters, such as deflection and frequency, can be obtained by using a film motion analyzer. The results show that the beam does not behave in a clamped-free or a pinned-free fashion, but instead occurs at an intermediate boundary between these two classical conditions.
Meyer, Anna Sina P; Meyer, Martin A S; Sørensen, Anne Marie;
2014-01-01
BACKGROUND: Viscoelastic hemostatic assays may provide means for earlier detection of trauma-induced coagulopathy (TIC). METHODS: This is a prospective observational study of 182 trauma patients admitted to a Level 1 trauma center. Clinical data, thrombelastography (TEG), and rotational thromboel......BACKGROUND: Viscoelastic hemostatic assays may provide means for earlier detection of trauma-induced coagulopathy (TIC). METHODS: This is a prospective observational study of 182 trauma patients admitted to a Level 1 trauma center. Clinical data, thrombelastography (TEG), and rotational...... ratio greater than 1.2 (TIC patients) as well as transfusion needs (no red blood cells [RBCs], 1-9 RBCs, and ≥10 RBC in 6 hours). Correlations were analyzed by Spearman's correlation. RESULTS: TIC patients had lower amplitudes than non-TIC patients in ROTEM/TEG as follows: EXTEM, INTEM, and FIBTEM: A5.......001) (CK, 16 [15-17] vs. 27 [25-30]; rTEG, 11 [11-11] vs. 18 [17-20]; EXTEM, 11 [11-11] vs. 29 [26-31]; and INTEM 13[12-13] vs. 25 [22-29]). CONCLUSION: Early amplitudes were lower in TIC patients, had significant correlations with MA/MCF, and differentiated between nontransfused and patients receiving one...
Towards a practical approach for self-consistent large amplitude collective motion
Almehed, D; Almehed, Daniel; Walet, Niels R.
2004-01-01
We investigate the use of an operatorial basis in a self-consistent theory of large amplitude collective motion. For the example of the pairing-plus-quadrupole model, which has been studied previously at equilibrium, we show that a small set of carefully chosen state-dependent basis operators is sufficient to approximate the exact solution of the problem accuratly. This approximation is used to study the interplay of quadrupole and pairing degrees of freedom along the collective path for realistic examples of nuclei. We show how this leads to a viable calculational scheme for studying nuclear structure, and discuss the surprising role of pairing collapse.
Quasielastic neutron scattering study of large amplitude motions in molecular systems
This lecture aims at giving some illustrations of the use of Incoherent Quasielastic Neutron Scattering in the investigation of motions of atoms or molecules in phases with dynamical disorder. The general incoherent scattering function is first recalled. Then the Elastic Incoherent Structure Factor is introduced. It is shown how its determination permits to deduce a particular dynamical model. Long-range translational diffusion is illustrated by some experiments carried out with liquids or with different chemical species intercalated in porous media. Examples of rotational motions are provided by solid phases where an orientational disorder of the molecules exists. The jump model is the most commonly used and yields simple scattering laws which can be easily handled. Highly disordered crystals require a description in terms of the isotropic rotational diffusion model. Many of the present studies are concerned with rather complicated systems. Considerable help is obtained either by using selectively deuterated samples or by carrying out measurements with semi-oriented samples. (author) 5 figs., 14 refs
Quasielastic neutron scattering study of large amplitude motions in molecular systems
Bee, M. [Univ. J. Fourier - Grenoble 1, Lab. de Spectrometrie Physique, Saint-Martin d`Heres (France)
1996-12-31
This lecture aims at giving some illustrations of the use of Incoherent Quasielastic Neutron Scattering in the investigation of motions of atoms or molecules in phases with dynamical disorder. The general incoherent scattering function is first recalled. Then the Elastic Incoherent Structure Factor is introduced. It is shown how its determination permits to deduce a particular dynamical model. Long-range translational diffusion is illustrated by some experiments carried out with liquids or with different chemical species intercalated in porous media. Examples of rotational motions are provided by solid phases where an orientational disorder of the molecules exists. The jump model is the most commonly used and yields simple scattering laws which can be easily handled. Highly disordered crystals require a description in terms of the isotropic rotational diffusion model. Many of the present studies are concerned with rather complicated systems. Considerable help is obtained either by using selectively deuterated samples or by carrying out measurements with semi-oriented samples. (author) 5 figs., 14 refs.
VIBRATION TECHNOLOGY WITH A LARGE AMPLITUDE OF PARTICLE MOTION OF FEED COMPONENTS
Marchenko A. Y.
2015-03-01
Full Text Available The article has revealed the contradiction between the way of technological impact and the means of implementation of technological transport in existing processes of feed preparation. There has been shown the possibility of eliminating this contradiction by menus of completely new technological equipment on the basis of relative screw drums and the opportunity to improve their productivity. There are no exciters in the offered design of vibrating machines. There is no need for them because the move mend of mass loading particles is provided by the original constructions of relative screw drums committing a rotary motion around its own axis. For implementing of feed preparation process the geometry of the relative screw drum and its dynamism must be individual: the shape, spatial orientation, the impact of forces providing feed components particles simultaneously with rotational-translational and vibrational motion. In the result, the continuously running through the inner cavity of the relative screw drum particles of feed components perform rotational-translational movements with super imposed vibrations inside this drum, due to this process the particles of feed components are mixed intensively
Observations are reported of rapid fluctuations in Faraday rotation angle (FRA) recorded at 137MHz and amplitude scintillation at 4 GHz. The observations were made at Suva, Fiji Islands (average ionospheric coordinates 170S, 1780E) and cover the period September, 1978 through March, 1983. Monthly occurrence of both the FRA fluctuations and the amplitude scintillation are positively correlated with sunspot number and negatively correlated with Ap and hmF2 at Tahiti. No events were seen in the summer months (November, December, and January) and it is suggested that the south to north neutral wind may be responsible for this. Maximum occurrence of both the 137 MHz FRA fluctuations and the 4 GHz scintillation is in April-May and August-September. The more rapid FRA fluctuations, termed here V-type, occur more often in months when the ambient electron density is larger. Most events occur in the pre-midnight sector, as observed elsewhere. Fewer 4 GHz events are observed at later times in the evening, as compared to the 137 MHz FRA fluctuations
Rare transition event with self-consistent theory of large-amplitude collective motion
Tsumura, Kyosuke, E-mail: kyosuke.tsumura@fujifilm.com; Maeda, Yoshitaka; Watanabe, Hiroyuki
2015-06-15
A numerical simulation method, based on Dang et al.’s self-consistent theory of large-amplitude collective motion, for rare transition events is presented. The method provides a one-dimensional pathway without knowledge of the final configuration, which includes a dynamical effect caused by not only a potential but also kinetic term. Although it is difficult to apply the molecular dynamics simulation to a narrow-gate potential, the method presented is applicable to the case. A toy model with a high-energy barrier and/or the narrow gate shows that while the Dang et al. treatment is unstable for a changing of model parameters, our method stable for it.
Rare transition event with self-consistent theory of large-amplitude collective motion
A numerical simulation method, based on Dang et al.’s self-consistent theory of large-amplitude collective motion, for rare transition events is presented. The method provides a one-dimensional pathway without knowledge of the final configuration, which includes a dynamical effect caused by not only a potential but also kinetic term. Although it is difficult to apply the molecular dynamics simulation to a narrow-gate potential, the method presented is applicable to the case. A toy model with a high-energy barrier and/or the narrow gate shows that while the Dang et al. treatment is unstable for a changing of model parameters, our method stable for it
Quadrupole shape dynamics in view from a theory of large amplitude collective motion
Matsuo, M; Sato, K; Matsuyanagi, K; Nakatsukasa, T; Yoshida, K
2014-01-01
Low-lying quadrupole shape dynamics is a typical manifestation of large amplitude collective motion in finite nuclei. To describe the dynamics on a microscopic foundation, we have formulated a consistent scheme in which the Bohr collective Hamiltonian for the five dimensional quadrupole shape variables is derived on the basis of the time-dependent Hartree-Fock-Bogoliubov theory. It enables us to incorporates the Thouless-Valatin effect on the shape inertial functions, which has been neglected in previous microscopic Bohr Hamiltonian approaches. Quantitative successes are illustrated for the low-lying spectra in $^{68}$Se, $^{30-34}$Mg and $^{58-64}$Cr, which display shape-coexistence, -mixing and -transitional behaviors.
Communication: Creation of molecular vibrational motions via the rotation-vibration coupling
Building on recent advances in the rotational excitation of molecules, we show how the effect of rotation-vibration coupling can be switched on in a controlled manner and how this coupling unfolds in real time after a pure rotational excitation. We present the first examination of the vibrational motions which can be induced via the rotation-vibration coupling after a pulsed rotational excitation. A time-dependent quantum wave packet calculation for the HF molecule shows how a slow (compared to the vibrational period) rotational excitation leads to a smooth increase in the average bond length whereas a fast rotational excitation leads to a non-stationary vibrational motion. As a result, under field-free postpulse conditions, either a stretched stationary bond or a vibrating bond can be created due to the coupling between the rotational and vibrational degrees of freedom. The latter corresponds to a laser-induced breakdown of the adiabatic approximation for rotation-vibration coupling
The Effect of Postoperative Passive Motion on Rotator Cuff Healing in a Rat Model
Peltz, Cathryn D.; Dourte, LeAnn M.; Kuntz, Andrew F.; Sarver, Joseph J.; Kim, Soung-Yon; Williams, Gerald R.; Soslowsky, Louis J.
2009-01-01
Background: Surgical repairs of torn rotator cuff tendons frequently fail. Immobilization has been shown to improve tissue mechanical properties in an animal model of rotator cuff repair, and passive motion has been shown to improve joint mechanics in animal models of flexor tendon repair. Our objective was to determine if daily passive motion would improve joint mechanics in comparison with continuous immobilization in a rat rotator cuff repair model. We hypothesized that daily passive motio...
Yeh, Shih-Ching; Wang, Jin-Liang; Wang, Chin-Yeh; Lin, Po-Han; Chen, Gwo-Dong; Rizzo, Albert
2014-01-01
Mental rotation is an important spatial processing ability and an important element in intelligence tests. However, the majority of past attempts at training mental rotation have used paper-and-pencil tests or digital images. This study proposes an innovative mental rotation training approach using magnetic motion controllers to allow learners to…
Stability of steady rotational water-waves of finite amplitude on arbitrary shear currents
Seez, William; Abid, Malek; Kharif, Christian
2016-04-01
A versatile solver for the two-dimensional Euler equations with an unknown free-surface has been developed. This code offers the possibility to calculate two-dimensional, steady rotational water-waves of finite amplitude on an arbitrary shear current. Written in PYTHON the code incorporates both pseudo-spectral and finite-difference methods in the discretisation of the equations and thus allows the user to capture waves with large steepnesses. As such it has been possible to establish that, in a counter-flowing situation, the existence of wave solutions is not guaranteed and depends on a pair of parameters representing mass flux and vorticity. This result was predicted, for linear solutions, by Constantin. Furthermore, experimental comparisons, both with and without vorticity, have proven the precision of this code. Finally, waves propagating on top of highly realistic shear currents (exponential profiles under the surface) have been calculated following current profiles such as those used by Nwogu. In addition, a stability analysis routine has been developed to study the stability regimes of base waves calculated with the two-dimensional code. This linear stability analysis is based on three dimensional perturbations of the steady situation which lead to a generalised eigenvalue problem. Common instabilities of the first and second class have been detected, while a third class of wave-instability appears due to the presence of strong vorticity. {1} Adrian Constantin and Walter Strauss. {Exact steady periodic water waves with vorticity}. Communications on Pure and Applied Mathematics, 57(4):481-527, April 2004. Okey G. Nwogu. {Interaction of finite-amplitude waves with vertically sheared current fields}. Journal of Fluid Mechanics, 627:179, May 2009.
Shannon L. Hoffman
2012-01-01
Full Text Available Reducing increased or early lumbopelvic motion during trunk or limb movements may be an important component of low back pain treatment. The ability to reduce lumbopelvic motion may be influenced by gender. The purpose of the current study was to examine the effect of gender on the ability of people with low back pain to reduce lumbopelvic motion during hip medial rotation following physical therapy treatment. Lumbopelvic rotation and hip rotation before the start of lumbopelvic rotation were assessed pre- and posttreatment for 16 females and 15 males. Both men and women decreased lumbopelvic rotation and completed more hip rotation before the start of lumbopelvic rotation post-treatment compared to pre-treatment. Men demonstrated greater lumbopelvic rotation and completed less hip rotation before the start of lumbopelvic rotation than women both pre- and post-treatment. Both men and women reduced lumbopelvic motion relative to their starting values, but, overall, men still demonstrated greater and earlier lumbopelvic motion. These results may have important implications for understanding differences in the evaluation and treatment of men and women with low back pain.
Effect of estimated torsional ground motion on lateral and rotational floor response spectra
The purpose is to describe the mathematical formulation used in computing the seismic response of equipment (the secondary system) located within an asymmetric building (the primary system) subjected to lateral and rotational base ground motions and to illustrate the influence of an estimated rotational ground motion on the response of the secondary system. The equipment response is represented by the floor response spectra. A rotational time history ground motion is generated to act in conjunction with the recorded lateral component. These two time history motions, are used as input motions applied at the base of an asymmetric building structure. The coupled lateral-torsional floor responses are determined. The resulting lateral floor motion of the structure is applied to a series of simple oscillators, each having an assumed damping ratio, and their maximum responses are plotted as a function of their natural periods. These plots represent the unsmoothed damped lateral floor response spectra obtained by a time history analysis. In a similar manner, rotational floor response spectra are obtained by applying the rotational floor motion to a series of torsional single-degree-of-freedom oscillators and plotting their maximum rotational responses as a function of their natural periods for a particular level of damping. The response results are analyzed to study the influence of the estimated torsional ground motion on both the lateral and rotational floor response spectra of such a structure. By comparing the results, one may conclude that the estimated rotational ground motion has a significant effect on the torsional floor response spectra. As a result, the edge lateral floor spectra are also affected significantly, both due to the direct torsional response of the building and also due to the direct transmission of the rotational ground motion throughout the entire frequency range. (orig./HP)
Governing equations and numerical solutions of tension leg platform with finite amplitude motion
ZENG Xiao-hui; SHEN Xiao-peng; WU Ying-xiang
2007-01-01
It is demonstrated that when tension leg platform (TLP) moves with finite amplitude in waves, the inertia force, the drag force and the buoyancy acting on the platform are nonlinear functions of the response of TLP. The tensions of the tethers are also nonlinear functions of the displacement of TLP. Then the displacement, the velocity and the acceleration of TLP should be taken into account when loads are calculated. In addition, equations of motions should be set up on the instantaneous position. A theoretical model for analyzing the nonlinear behavior of a TLP with finite displacement is developed, in which multifold nonlinearities are taken into account, i.e., finite displacement, coupling of the six degrees of freedom, instantaneous position, instantaneous wet surface, free surface effects and viscous drag force. Based on the theoretical model, the comprehensive nonlinear differential equations are deduced. Then the nonlinear dynamic analysis of ISSC TLP in regular waves is performed in the time domain. The degenerative linear solution of the proposed nonlinear model is verified with existing published one.Furthermore, numerical results are presented, which illustrate that nonlinearities exert a significant influence on the dynamic responses of the TLP.
Stallcop, J. R.
1971-01-01
Collision-induced vibration-rotation transition probabilities are calculated from a semiclassical three-dimensional model, in which the collision trajectory is determined by the classical motion in the interaction potential that is averaged over the molecular rotational state, and compared with those for which the motion is governed by a spherically averaged potential. For molecules that are in highly excited rotational states, thus dominating the vibrational relaxation rate at high temperature, it is found that the transition probability for rotational state averaging is smaller than that for spherical averaging. For typical collisions, the transition cross section is decreased by a factor of about 1.5 to 2.
Forming rotated SAR images by real-time motion compensation.
Doerry, Armin Walter
2012-12-01
Proper waveform parameter selection allows collecting Synthetic Aperture Radar (SAR) phase history data on a rotated grid in the Fourier Space of the scene being imaged. Subsequent image formation preserves the rotated geometry to allow SAR images to be formed at arbitrary rotation angles without the use of computationally expensive interpolation or resampling operations. This should be useful where control of image orientation is desired such as generating squinted stripmaps and VideoSAR applications, among others.
Hip rotation range of motion in sitting and prone positions in healthy Japanese adults
Han, Heonsoo; Kubo, Akira; Kurosawa, Kazuo; Maruichi, Shizuka; Maruyama, Hitoshi
2015-01-01
[Purpose] The aim of this study was to elucidate the difference in hip external and internal rotation ranges of motion (ROM) between the prone and sitting positions. [Subjects] The subjects included 151 students. [Methods] Hip rotational ROM was measured with the subjects in the prone and sitting positions. Two-way repeated measures analysis of variance (ANOVA) was used to analyze ipsilateral hip rotation ROM in the prone and sitting positions in males and females. The total ipsilateral hip rotation ROM was calculated by adding the measured values for external and internal rotations. [Results] Ipsilateral hip rotation ROM revealed significant differences between two positions for both left and right internal and external rotations. Hip rotation ROM was significantly higher in the prone position than in the sitting position. Hip rotation ROM significantly differed between the men and women. Hip external rotation ROM was significantly higher in both positions in men; conversely, hip internal rotation ROM was significantly higher in both positions in women. [Conclusion] Hip rotation ROM significantly differed between the sexes and between the sitting and prone positions. Total ipsilateral hip rotation ROM, total angle of external rotation, and total angle of internal rotation of the left and right hips greatly varied, suggesting that hip joint rotational ROM is widely distributed. PMID:25729186
Solar Magnetized Tornadoes: Rotational Motion in a Tornado-like Prominence
Su, Yang; Gömöry, Peter; Veronig, Astrid; Temmer, Manuela; Wang, Tongjiang; Vanninathan, Kamalam; Gan, Weiqun; Li, Youping
2013-01-01
Su et al. 2012 proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions s...
Chaotic motion of particles in the accelerating and rotating black holes spacetime
Chen, Songbai; Wang, Mingzhi; Jing, Jiliang
2016-01-01
We have investigated the motion of timelike particles along geodesic in the background of accelerating and rotating black hole spacetime. We confirmed that the chaos exists in the geodesic motion of the particles by Poincar\\'e sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram. Moreover, we probe the effects of the acceleration and rotation parameters on the chaotic behavior of a timelike geodesic particle in the black hole spacetime. Our results sh...
Low-amplitude rotational modulation rather than pulsations in the CoRoT B-type supergiant HD 46769
Aerts, C.; Simón-Díaz, S.; Catala, C.; Neiner, C.; Briquet, M.; Castro, N.; Schmid, V. S.; Scardia, M.; Rainer, M.; Poretti, E.; Pápics, P. I.; Degroote, P.; Bloemen, S.; Østensen, R. H.; Auvergne, M.; Baglin, A.; Baudin, F.; Michel, E.; Samadi, R.
2013-09-01
Aims: We aim to detect and interpret photometric and spectroscopic variability of the bright CoRoT B-type supergiant target HD 46769 (V = 5.79). We also attempt to detect a magnetic field in the target. Methods: We analyse a 23-day oversampled CoRoT light curve after detrending and spectroscopic follow-up data using standard Fourier analysis and phase dispersion minimization methods. We determine the fundamental parameters of the star, as well as its abundances from the most prominent spectral lines. We perform a Monte Carlo analysis of spectropolarimetric data to obtain an upper limit of the polar magnetic field, assuming a dipole field. Results: In the CoRoT data, we detect a dominant period of 4.84 d with an amplitude of 87 ppm and some of its (sub-)multiples. Given the shape of the phase-folded light curve and the absence of binary motion, we interpret the dominant variability in terms of rotational modulation, with a rotation period of 9.69 d. Subtraction of the rotational modulation signal does not reveal any sign of pulsations. Our results are consistent with the absence of variability in the Hipparcos light curve. The spectroscopy leads to a projected rotational velocity of 72 ± 2 km s-1 and does not reveal periodic variability or the need to invoke macroturbulent line broadening. No signature of a magnetic field is detected in our data. A field stronger than ~500 G at the poles can be excluded, unless the possible non-detected field were more complex than dipolar. Conclusions: The absence of pulsations and macroturbulence of this evolved B-type supergiant is placed into the context of instability computations and of observed variability of evolved B-type stars. Based on CoRoT space-based photometric data; the CoRoT space mission was developed and operated by the French space agency CNES, with the participation of ESA's RSSD and Science Programmes, Austria, Belgium, Brazil, Germany, and Spain. Based on observations collected at La Silla Observatory, ESO
Visual Reinforcement of Illusory Rotations: Habituation to Motion Sickness during Centrifugation
Bertolini, G.; Bos, J.E.; Bron, D; Groen, E.; Wuyts, F.L.; Hemmersbach, R.; Petrat, G.; Frett, T.
2015-01-01
Artificial gravity through centrifugation is currently seen as countermeasure with potential against negative effects of spaceflight. However, side effects like increased motion sickness need to be investigated. Habituation protocols abate conflicts by reducing response to rotation with prolonged exposure to mismatches. Visually reinforced habituation may induce less reduction of oculomotor response to rotation than classical habituation.
Holler, Mirko; Raabe, Jörg
2015-05-01
The nonaxial interferometric position measurement of rotating objects can be performed by imaging the laser beam of the interferometer to a rotating mirror which can be a sphere or a cylinder. This, however, requires such rotating mirrors to be centered on the axis of rotation as a wobble would result in loss of the interference signal. We present a tracking-type interferometer that performs such measurement in a general case where the rotating mirror may wobble on the axis of rotation, or even where the axis of rotation may be translating in space. Aside from tracking, meaning to measure and follow the position of the rotating mirror, the interferometric measurement errors induced by the tracking motion of the interferometer itself are optically compensated, preserving nanometric measurement accuracy. As an example, we show the application of this interferometer in a scanning x-ray tomography instrument.
Hip rotation range of motion in sitting and prone positions in healthy Japanese adults
Han, Heonsoo; Kubo, Akira; Kurosawa, Kazuo; Maruichi, Shizuka; Maruyama, Hitoshi
2015-01-01
[Purpose] The aim of this study was to elucidate the difference in hip external and internal rotation ranges of motion (ROM) between the prone and sitting positions. [Subjects] The subjects included 151 students. [Methods] Hip rotational ROM was measured with the subjects in the prone and sitting positions. Two-way repeated measures analysis of variance (ANOVA) was used to analyze ipsilateral hip rotation ROM in the prone and sitting positions in males and females. The total ipsilateral hip r...
Mikhailov, Eugeniy E.; Goda, Keisuke; Corbitt, Thomas; Mavalvala, Nergis
2005-01-01
We study the effects of frequency-dependent squeeze amplitude attenuation and squeeze angle rotation by electromagnetically induced transparency (EIT) on gravitational wave (GW) interferometers. We propose the use of low-pass, band-pass, and high-pass EIT filters, an S-shaped EIT filter, and an intra-cavity EIT filter to generate frequency-dependent squeezing for injection into the antisymmetric port of GW interferometers. We find that the EIT filters have several advantages over the previous...
Simulation-based analysis of the micropropulsion with rotating corkscrew motion of the flagella
Koz, Mustafa; Yeşilyurt, Serhat; Yesilyurt, Serhat
2009-01-01
Microorganisms such as ecoli bacterium can propel themselves by means of a corkscrew motion in flow regimes where the Reynolds number is much smaller than one and inertial propulsion methods are ineffective. Micropropulsion with the rotating corkscrew motion of flagella can prove useful as a navigation mechanism for microswimming robots in medical applications. In this work, we present the motion of a microswimmer that consists of an ellipsoid of length two-microns and diameter one micron wit...
MEASUREMENT OF ANGULAR VIBRATION AMPLITUDE BY ACTIVELY BLURRED IMAGES
GUAN Baiqing; WANG Shigang; LIU Chong; LI Qian
2007-01-01
A novel motion-blur-based method for measuring the angular amplitude of a high-frequency rotational vibration is schemed. The proposed approach combines the active vision concept and the mechanism of motion-from-blur, generates motion blur on the image plane actively by extending exposure time, and utilizes the motion blur information in polar images to estimate the angular amplitude of a high-frequency rotational vibration. This method obtains the analytical results of the angular vibration amplitude from the geometric moments of a motion blurred polar image and an unblurred image for reference. Experimental results are provided to validate the presented scheme.
Semi-analytical study of the rotational motion stability of artificial satellites using quaternions
This study at aims performing the stability analysis of the rotational motion to artificial satellites using quaternions to describe the satellite attitude (orientation on the space). In the system of rotational motion equations, which is composed by four kinematic equations of the quaternions and by the three Euler equations in terms of the rotational spin components. The influence of the gravity gradient and the direct solar radiation pressure torques have been considered. Equilibrium points were obtained through numerical simulations using the softwares Matlab and Octave, which are then analyzed by the Routh-Hurwitz Stability Criterion
Semi-analytical study of the rotational motion stability of artificial satellites using quaternions
Cardoso dos Santos, Josué; Zanardi, Maria Cecília; Matos, Nicholas
2013-10-01
This study at aims performing the stability analysis of the rotational motion to artificial satellites using quaternions to describe the satellite attitude (orientation on the space). In the system of rotational motion equations, which is composed by four kinematic equations of the quaternions and by the three Euler equations in terms of the rotational spin components. The influence of the gravity gradient and the direct solar radiation pressure torques have been considered. Equilibrium points were obtained through numerical simulations using the softwares Matlab and Octave, which are then analyzed by the Routh-Hurwitz Stability Criterion.
Chaotic motion of particles in the accelerating and rotating black holes spacetime
Chen, Songbai; Jing, Jiliang
2016-01-01
We have investigated the motion of timelike particles along geodesic in the background of accelerating and rotating black hole spacetime. We confirmed that the chaos exists in the geodesic motion of the particles by Poincar\\'e sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram. Moreover, we probe the effects of the acceleration and rotation parameters on the chaotic behavior of a timelike geodesic particle in the black hole spacetime. Our results show that the acceleration brings richer physics for the geodesic motion of particles.
Rosales-Guzmán, Carmelo; Belmonte, Aniceto; Torres, Juan P
2014-01-01
We measure the rotational and translational velocity components of particles moving in helical motion using the frequency shift they induced to the structured light beam illuminating them. Under Laguerre-Gaussian mode illumination, a particle with a helical motion reflects light that acquires an additional frequency shift proportional to the angular velocity of rotation in the transverse plane, on top of the usual frequency shift due to the longitudinal motion. We determined both the translational and rotational velocities of the particles by switching between two modes: by illuminating with a Gaussian beam, we can isolate the longitudinal frequency shift; and by using a Laguerre-Gaussian mode, the frequency shift due to the rotation can be determined. Our technique can be used to characterize the motility of microorganisms with a full three-dimensional movement.
Hoots, F. R.; Fitzpatrick, P. M.
1979-01-01
The classical Poisson equations of rotational motion are used to study the attitude motions of an earth orbiting, rapidly spinning gyroscope perturbed by the effects of general relativity (Einstein theory). The center of mass of the gyroscope is assumed to move about a rotating oblate earth in an evolving elliptic orbit which includes all first-order oblateness effects produced by the earth. A method of averaging is used to obtain a transformation of variables, for the nonresonance case, which significantly simplifies the Poisson differential equations of motion of the gyroscope. Long-term solutions are obtained by an exact analytical integration of the simplified transformed equations. These solutions may be used to predict both the orientation of the gyroscope and the motion of its rotational angular momentum vector as viewed from its center of mass. The results are valid for all eccentricities and all inclinations not near the critical inclination.
To development of analytical theory of rotational motion of the Moon
Barkin, Yu. V.; Ferrandiz, J. M.; Navarro, J. F.
2009-04-01
Resume. In the work the analytical theory of forced librations of the Moon considered as a celestial body with a liquid core and rigid non-spherical mantle is developed. For the basic variables: Andoyer, Poincare and Eulerian angles, and also for various dynamic characteristics of the Moon the tables for amplitudes, periods and phases of perturbations of the first order have been constructed. Resonant periods of free librations have been estimated. The influence of a liquid core results in decreasing of the period of free librations in longitude approximately on 0.316 day, and in change of the period of free pole wobble of the Moon on 25.8 days. In the first approximation the liquid core does not render influence on the value of Cassini's inclination and on the period of precession of the angular momentum vector. However it causes an additional "quasi-diurnal" librations with period about 27.165 days. In comparison with model of rigid non-spherical of the Moon the presence of a liquid core should result in increase of amplitudes of the Moon librations in longitude on 0.06 %. 1 Development of analytical theory of rotational motion of the Moon with liquid core and rigid mantle. The work has been realized in following stages. 1. Canonical equations of rotation of the Moon with liquid core and elastic mantle in Andoyer and Poincare variables have been constructed. Developments of second harmonic of force function of the Moon in pointed variables have been obtained for accurate trigonometric presentation of perturbations of the Moon orbital motion. 2. Two approaches (two methods) of construction of analytical theory have been developed. These approaches use different principles for eliminating of singularities for axial rotation of the Moon. One is based on direct application of Andoyer variables by changing of notations of moments of inertia [1]. Second is based on application of Poincare elements. For comparison both approaches are developed. 3. The main equation for
Manipulation of molecular vibrational motions via pure rotational excitations
Shu, Chuan-Cun; Henriksen, Niels Engholm
2015-01-01
The coupling between different molecular degrees of freedom plays a decisive role in many quantum phenomena, including electron transfer and energy redistribution. Here, we demonstrate a quantum-mechanical time-dependent simulation to explore how a vibrational motion in a molecule can be affected...
Motion of rotating spherical particles touching a wall
Chára, Zdeněk; Vlasák, Pavel; Keita, Ibrahima
Prague : ITAM AS CR, v. v. i., 2012 - (Náprstek, J.; Fischer, C.), s. 513-521 ISBN 978-80-86246-40-6. [ Engineering Mechanics 2012 /18./. Svratka (CZ), 14.05.2012-17.05.2012] R&D Projects: GA ČR GA103/09/1718 Institutional support: RVO:67985874 Keywords : particle rotation * particle trajectory * Magnus force Subject RIV: BK - Fluid Dynamics
Graybill, George
2007-01-01
Take the mystery out of motion. Our resource gives you everything you need to teach young scientists about motion. Students will learn about linear, accelerating, rotating and oscillating motion, and how these relate to everyday life - and even the solar system. Measuring and graphing motion is easy, and the concepts of speed, velocity and acceleration are clearly explained. Reading passages, comprehension questions, color mini posters and lots of hands-on activities all help teach and reinforce key concepts. Vocabulary and language are simplified in our resource to make them accessible to str
Using pusher-plate-type artificial hearts, changes in the degree of synchrony and stroke volume were compared to phase and amplitude calculations from the first Fourier component of individual-pixel time-activity curves generated from gated radionuclide images (RNA) of these hearts. In addition, the ability of Fourier analysis to quantify paradoxical volume shifts was tested using a ventricular aneurysm model by which the Fourier amplitude was correlated to known increments of paradoxical volume. Predetermined phase-angle differences (incremental increases in asynchrony) and the mean phase-angle difference calculated from RNAs showed an agreement of -70+-4.40 (mean +-SD). A strong correlation was noted between stroke volume and Fourier amplitude (r=0.98; P<0.0001) as well as between the paradoxical volume accepted by the 'aneurysm' and the Fourier amplitude (r=0.97; P<0.0001). The degree of asynchrony and changes in stroke volume were accurately reflected by the Fourier phase and amplitude values, respectively. In the specific case of ventricular aneurysms, the data demonstrate that using this method, the paradoxically moving areas may be localized, and the expansile volume within these regions can be quantified. (orig.)
The transverse and rotational motions of magnetohydrodynamic kink waves in the solar atmosphere
Magnetohydrodynamic (MHD) kink waves have now been observed to be ubiquitous throughout the solar atmosphere. With modern instruments, they have now been detected in the chromosphere, interface region, and corona. The key purpose of this paper is to show that kink waves do not only involve purely transverse motions of solar magnetic flux tubes, but the velocity field is a spatially and temporally varying sum of both transverse and rotational motion. Taking this fact into account is particularly important for the accurate interpretation of varying Doppler velocity profiles across oscillating structures such as spicules. It has now been shown that, as well as bulk transverse motions, spicules have omnipresent rotational motions. Here we emphasize that caution should be used before interpreting the particular MHD wave mode/s responsible for these rotational motions. The rotational motions are not necessarily signatures of the classic axisymmetric torsional Alfvén wave alone, because kink motion itself can also contribute substantially to varying Doppler velocity profiles observed across these structures. In this paper, the displacement field of the kink wave is demonstrated to be a sum of its transverse and rotational components, both for a flux tube with a discontinuous density profile at its boundary, and one with a more realistic density continuum between the internal and external plasma. Furthermore, the Doppler velocity profile of the kink wave is forward modeled to demonstrate that, depending on the line of sight, it can either be quite distinct or very similar to that expected from a torsional Alfvén wave.
Effect of arthroscopic rotator cuff surgery in patients with preoperative restricted range of motion
Razmjou, Helen; Henry, Patrick; Costa, Giuseppe; Dwyer, Tim; Holtby, Richard
2016-01-01
Background The purpose of this study was to examine the impact of rotator cuff (RC) decompression and/or repair on post-operative ROM in patients with pre-operative restricted passive motion who had undergone arthroscopic subacromial debridement and/or rotator cuff repair. Potential predictors of ROM recovery such as age, sex, mechanism of injury, type of surgery, presence of an endocrine illness and having an active Worker Compensation claim related to the shoulder were explored. Methods A r...
Determining the rotational motion of the Bion M-1 satellite with the GRAVITON instrument
Abrashkin, V. I.; Voronov, K. E.; Piyakov, I. V.; Puzin, Yu. Ya.; Sazonov, V. V.; Semkin, N. D.; Chebukov, S. Yu.
2015-07-01
Actual controlled rotational motion of the Bion M-1 satellite is reconstructed for the modes of the orbital and single-axis solar orientation. The reconstruction was performed using data of onboard measurements of the vectors of angular velocity and the Earth's magnetic field (EMF) strength. The reconstruction procedure is based on the kinematic equations of the rotational motion of a solid body. In the framework of this procedure, measurement data for two types collected at a certain time interval are processed jointly. Measurements of angular velocity are interpolated by piecewise-linear functions, which are substituted in the kinematic differential equations for quaternion giving the transition from the satellite instrument coordinate system to the inertial (the second geoequatorial) coordinate system. Thus the obtained equations represent the kinematic model of the satellite rotational motion. The solution to these equations approximating the actual motion is derived from the condition of the best (in the sense of the least-square method) matching measurement data of the EMF strength vector with the calculated values. The described procedure allows us to reconstruct the actual rotational satellite motion using one solution to kinematic equations over time intervals with durations of more than 5 h. Found reconstructions were used to calculate the residual microaccelerations.
SOLAR MAGNETIZED TORNADOES: ROTATIONAL MOTION IN A TORNADO-LIKE PROMINENCE
Su, Yang; Veronig, Astrid; Temmer, Manuela; Vanninathan, Kamalam [IGAM-Kanzelhöhe Observatory, Institute of Physics, University of Graz, Universitätsplatz 5, A-8010 Graz (Austria); Gömöry, Peter [Astronomical Institute of the Slovak Academy of Sciences, SK-05960 Tatranská Lomnica (Slovakia); Wang, Tongjiang [Department of Physics, the Catholic University of America, Washington, DC 20064 (United States); Gan, Weiqun; Li, YouPing, E-mail: yang.su@uni-graz.at [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)
2014-04-10
Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions such as oscillation and counter-streaming plasma flows. Here we report evidence of rotational motions in a tornado-like prominence. The spectroscopic observations in two coronal lines were obtained from a specifically designed Hinode/EIS observing program. The data revealed the existence of both cold and million-degree-hot plasma in the prominence leg, supporting the so-called prominence-corona transition region. The opposite velocities at the two sides of the prominence and their persistent time evolution, together with the periodic motions evident in SDO/AIA dark structures, indicate a rotational motion of both cold and hot plasma with a speed of ∼5 km s{sup –1}.
SOLAR MAGNETIZED TORNADOES: ROTATIONAL MOTION IN A TORNADO-LIKE PROMINENCE
Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions such as oscillation and counter-streaming plasma flows. Here we report evidence of rotational motions in a tornado-like prominence. The spectroscopic observations in two coronal lines were obtained from a specifically designed Hinode/EIS observing program. The data revealed the existence of both cold and million-degree-hot plasma in the prominence leg, supporting the so-called prominence-corona transition region. The opposite velocities at the two sides of the prominence and their persistent time evolution, together with the periodic motions evident in SDO/AIA dark structures, indicate a rotational motion of both cold and hot plasma with a speed of ∼5 km s–1
Solar Magnetized Tornadoes: Rotational Motion in a Tornado-like Prominence
Su, Yang; Gömöry, Peter; Veronig, Astrid; Temmer, Manuela; Wang, Tongjiang; Vanninathan, Kamalam; Gan, Weiqun; Li, YouPing
2014-04-01
Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions such as oscillation and counter-streaming plasma flows. Here we report evidence of rotational motions in a tornado-like prominence. The spectroscopic observations in two coronal lines were obtained from a specifically designed Hinode/EIS observing program. The data revealed the existence of both cold and million-degree-hot plasma in the prominence leg, supporting the so-called prominence-corona transition region. The opposite velocities at the two sides of the prominence and their persistent time evolution, together with the periodic motions evident in SDO/AIA dark structures, indicate a rotational motion of both cold and hot plasma with a speed of ~5 km s-1.
Solar Magnetized "Tornadoes': Evidence for Rotational Motion in a Tornado-like Prominence
Su, Yang; Veronig, Astrid; Temmer, Manuela; Wang, Tongjiang; Vanninathan, Kamalam; Gan, Weiqun; Li, Youping
2013-01-01
Su et al. (2012) proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as ``tornado-like prominences'' when they appear above the limb. They may play a key role as the source of plasma and twists in filament. However, no observations have successfully identified rotational motion of the magnetic structure itself from other motions such as oscillation and plasma flow. Here we report the first solid evidence of rotational motions in a tornado-like prominence obtained from spectroscopic observations in two coronal lines in the frame of a specifically designed Hinode/EIS observing program. The opposite velocities at the two sides of the prominence and their time evolution, together with the periodic motions evident in SDO/AIA images, indicate a rotational motion with a speed of $\\sim$5 km s$^{-1}$. The data also revealed the existence of both cold and million-degree-hot p...
The interdependence among the strong-motion amplitude, earthquake magnitude and hypocentral distance has been established (Parvez et al. 2001) for the Himalayan region using the dataset of six earthquakes, two from Western and four from Eastern Himalayas (Mw=5.2-7.2) recorded by strong-motion networks in the Himalayas. The level of the peak strong motion amplitudes in the Eastern Himalayas is three fold larger than that in the Western Himalayas, in terms of both peak acceleration and peak velocities. In the present study, we include the strong motion data of Chamoli earthquake (Mw=6.5) of 1999 from the western sub-region to see whether this event supports the regional effects and we find that the new result fits well with our earlier prediction in the Western Himalayas. The minimum estimates of peak acceleration for the epicentral zone of Mw=7.5-8.5 events is Apeak=0.25-0.4 g for the Western Himalayas and as large as Apeak=1.0-1.6 g for the Eastern Himalayas. Similarly, the expected minimum epicentral values of Vpeak for Mw=8 are 35 cm/s for Western and 112 cm/s for Eastern Himalayas. The presence of unusually high levels of epicentral amplitudes for the eastern subregion also agrees well with the macroseismic evidence (Parvez et al. 2001). Therefore, these results represent systematic regional effects, and may be considered as a basis for future regionalized seismic hazard assessment in the Himalayan region. Many metropolitan and big cities of India are situated in the severe hazard zone just south of the Himalayas. A detailed microzonation study of these sprawling urban centres is therefore urgently required for gaining a better understanding of ground motion and site effects in these cities. An example of the study of site effects and microzonation of a part of metropolitan Delhi is presented based on a detailed modelling along a NS cross sections from the Inter State Bus Terminal (ISBT) to Sewanagar. Full synthetic strong motion waveforms have been computed
Briant, M; Mengesha, E; de Pujo, P; Gaveau, M-A; Soep, B; Mestdagh, J-M; Poisson, L
2016-06-28
Superfluid helium droplets provide an ideal environment for spectroscopic studies with rotational resolution. Nevertheless, the molecular rotation is hindered because the embedded molecules are surrounded by a non-superfluid component. The present work explores the dynamical role of this component in the hindered rotation of C2H2 within the C2H2-Ne complex. A HENDI experiment was built and near-infrared spectroscopy of C2H2-Ne and C2H2 was performed in the spectral region overlapping the ν3/ν2 + ν4 + ν5 Fermi-type resonance of C2H2. The comparison between measured and simulated spectra helped to address the above issue. PMID:27263427
Numerical Simulation of Microcarrier Motion in a Rotating Wall Vessel Bioreactor
ZHI-HAO JU; TIAN-QING LIU; XUE-HU MA; ZHAN-FENG CUI
2006-01-01
Objective To analyze the forces of rotational wall vessel (RWV) bioreactor on small tissue pieces or microcarrier particles and to determine the tracks of microcarrier particles in RWV bioreactor. Methods The motion of the microcarrier in the rotating wall vessel (RWV) bioreactor with both the inner and outer cylinders rotating was modeled by numerical simulation. Results The continuous trajectory of microcarrier particles, including the possible collision with the wall was obtained. An expression between the minimum rotational speed difference of the inner and outer cylinders and the microcarrier particle or aggregate radius could avoid collisions with either wall. The range of microcarrier radius or tissue size, which could be safely cultured in the RWV bioreactor, in terms of shear stress level, was determined. Conclusion The model works well in describing the trajectory of a heavier microcarrier particle in rotating wall vessel.
Wireless System and Method for Collecting Motion and Non-Motion Related Data of a Rotating System
Woodard, Stanley E. (Inventor); Taylor, Bryant D. (Inventor)
2011-01-01
A wireless system for collecting data indicative of a tire's characteristics uses at least one open-circuit electrical conductor in a tire. The conductor is shaped such that it can store electrical and magnetic energy. In the presence of a time-varying magnetic field, the conductor resonates to generate a harmonic response having a frequency, amplitude and bandwidth. A magnetic field response recorder is used to (i) wirelessly transmit the time-varying magnetic field to the conductor, and (ii) wirelessly detect the harmonic response and the frequency, amplitude and bandwidth, associated therewith. The recorder is adapted to be positioned in a location that is fixed with respect to the tire as the tire rotates.
The method of construction of nuclear collective Hamiltonians with discrete symmetries has been considered. The method allows to construct the collective Hamiltonians using O(3) tensors as building blocks. The formula for general form of the rotational reduced matrix elements is derived. (author)
We present the first detailed assessment of the large-scale rotation of any galaxy based on full three-dimensional velocity measurements. We do this for the LMC by combining our Hubble Space Telescope average proper motion (PM) measurements for stars in 22 fields, with existing line-of-sight (LOS) velocity measurements for 6790 individual stars. We interpret these data with a model of circular rotation in a flat disk. The PM and LOS data paint a consistent picture of the LMC rotation, and their combination yields several new insights. The PM data imply a stellar dynamical center that coincides with the H I dynamical center, and a rotation curve amplitude consistent with that inferred from LOS velocity studies. The implied disk viewing angles agree with the range of values found in the literature, but continue to indicate variations with stellar population and/or radius. Young (red supergiant) stars rotate faster than old (red and asymptotic giant branch) stars due to asymmetric drift. Outside the central region, the circular velocity is approximately flat at V circ = 91.7 ± 18.8 km s–1. This is consistent with the baryonic Tully-Fisher relation and implies an enclosed mass M(8.7 kpc) = (1.7 ± 0.7) × 1010 M ☉. The virial mass is larger, depending on the full extent of the LMC's dark halo. The tidal radius is 22.3 ± 5.2 kpc (24.°0 ± 5.°6). Combination of the PM and LOS data yields kinematic distance estimates for the LMC, but these are not yet competitive with other methods.
Event-based motion correction for PET transmission measurements with a rotating point source
Accurate attenuation correction is important for quantitative positron emission tomography (PET) studies. When performing transmission measurements using an external rotating radioactive source, object motion during the transmission scan can distort the attenuation correction factors computed as the ratio of the blank to transmission counts, and cause errors and artefacts in reconstructed PET images. In this paper we report a compensation method for rigid body motion during PET transmission measurements, in which list mode transmission data are motion corrected event-by-event, based on known motion, to ensure that all events which traverse the same path through the object are recorded on a common line of response (LOR). As a result, the motion-corrected transmission LOR may record a combination of events originally detected on different LORs. To ensure that the corresponding blank LOR records events from the same combination of contributing LORs, the list mode blank data are spatially transformed event-by-event based on the same motion information. The number of counts recorded on the resulting blank LOR is then equivalent to the number of counts that would have been recorded on the corresponding motion-corrected transmission LOR in the absence of any attenuating object. The proposed method has been verified in phantom studies with both stepwise movements and continuous motion. We found that attenuation maps derived from motion-corrected transmission and blank data agree well with those of the stationary phantom and are significantly better than uncorrected attenuation data.
Nicu, Valentin P; Domingos, Sérgio R; Strudwick, Benjamin H; Brouwer, Albert M; Buma, Wybren J
2016-01-11
A detailed analysis of the computed structure, energies, vibrational absorption (VA) and circular dichroism (VCD) spectra of 30 low-energy conformers of dehydroquinidine reveals the existence of families of pseudo-conformers, the structures of which differ mostly in the orientation of a single O-H bond. The pseudo-conformers in a family are separated by very small energy barriers (i.e., 1.0 kcal mol(-1) or smaller) and have very different VCD spectra. First, we demonstrate the unreliable character of the Boltzmann factors predicted with DFT. Then, we show that the large differences observed between the VCD spectra of the pseudo-conformers in a family are caused by large-amplitude motions involving the O-H bond, which trigger the appearance/disappearance of strong VCD exciton-coupling bands in the fingerprint region. This interplay between exciton coupling and large-amplitude-motion phenomena demonstrates that when dealing with flexible molecules with polar bonds, vibrational averaging of VCD spectra should not be neglected. In this regard, the dehydroquinidine molecule considered here is expected to be a typical example and not the exception to the rule. PMID:26611817
ROTATING MOTIONS AND MODELING OF THE ERUPTING SOLAR POLAR-CROWN PROMINENCE ON 2010 DECEMBER 6
Su, Yingna; Van Ballegooijen, Adriaan, E-mail: ynsu@head.cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
2013-02-10
A large polar-crown prominence composed of different segments spanning nearly the entire solar disk erupted on 2010 December 6. Prior to the eruption, the filament in the active region part split into two layers: a lower layer and an elevated layer. The eruption occurs in several episodes. Around 14:12 UT, the lower layer of the active region filament breaks apart: One part ejects toward the west, while the other part ejects toward the east, which leads to the explosive eruption of the eastern quiescent filament. During the early rise phase, part of the quiescent filament sheet displays strong rolling motion (observed by STEREO-B) in the clockwise direction (viewed from east to west) around the filament axis. This rolling motion appears to start from the border of the active region, then propagates toward the east. The Atmospheric Imaging Assembly (AIA) observes another type of rotating motion: In some other parts of the erupting quiescent prominence, the vertical threads turn horizontal, then turn upside down. The elevated active region filament does not erupt until 18:00 UT, when the erupting quiescent filament has already reached a very large height. We develop two simplified three-dimensional models that qualitatively reproduce the observed rolling and rotating motions. The prominence in the models is assumed to consist of a collection of discrete blobs that are tied to particular field lines of a helical flux rope. The observed rolling motion is reproduced by continuous twist injection into the flux rope in Model 1 from the active region side. Asymmetric reconnection induced by the asymmetric distribution of the magnetic fields on the two sides of the filament may cause the observed rolling motion. The rotating motion of the prominence threads observed by AIA is consistent with the removal of the field line dips in Model 2 from the top down during the eruption.
ROTATING MOTIONS AND MODELING OF THE ERUPTING SOLAR POLAR-CROWN PROMINENCE ON 2010 DECEMBER 6
A large polar-crown prominence composed of different segments spanning nearly the entire solar disk erupted on 2010 December 6. Prior to the eruption, the filament in the active region part split into two layers: a lower layer and an elevated layer. The eruption occurs in several episodes. Around 14:12 UT, the lower layer of the active region filament breaks apart: One part ejects toward the west, while the other part ejects toward the east, which leads to the explosive eruption of the eastern quiescent filament. During the early rise phase, part of the quiescent filament sheet displays strong rolling motion (observed by STEREO-B) in the clockwise direction (viewed from east to west) around the filament axis. This rolling motion appears to start from the border of the active region, then propagates toward the east. The Atmospheric Imaging Assembly (AIA) observes another type of rotating motion: In some other parts of the erupting quiescent prominence, the vertical threads turn horizontal, then turn upside down. The elevated active region filament does not erupt until 18:00 UT, when the erupting quiescent filament has already reached a very large height. We develop two simplified three-dimensional models that qualitatively reproduce the observed rolling and rotating motions. The prominence in the models is assumed to consist of a collection of discrete blobs that are tied to particular field lines of a helical flux rope. The observed rolling motion is reproduced by continuous twist injection into the flux rope in Model 1 from the active region side. Asymmetric reconnection induced by the asymmetric distribution of the magnetic fields on the two sides of the filament may cause the observed rolling motion. The rotating motion of the prominence threads observed by AIA is consistent with the removal of the field line dips in Model 2 from the top down during the eruption.
Survey of large-amplitude flapping motions in the midtail current sheet
V. A. Sergeev
2006-08-01
Full Text Available
We surveyed fast current sheet crossings (flapping motions over the distance range 10–30 R_{E} in the magnetotail covered by the Geotail spacecraft. Since the local tilts of these dynamic sheets are large and variable in these events, we compare three different methods of evaluating current sheet normals using 4-s/c Cluster data and define the success criteria for the single-spacecraft-based method (MVA to obtain the reliable results. Then, after identifying more than ~1100 fast CS crossings over a 3-year period of Geotail observations in 1997–1999, we address their parameters, spatial distribution and activity dependence. We confirm that over the entire distance covered and LT bins, fast crossings have considerable tilts in the YZ plane (from estimated MVA normals which show a preferential appearance of one (YZ kink-like mode that is responsible for these severe current sheet perturbations. Their occurrence is highly inhomogeneous; it sharply increases with radial distance and has a peak in the tail center (with some duskward shift, resembling the occurrence of the BBFs, although there is no one-to-one local correspondence between these two phenomena. The crossing durations typically spread around 1 min and decrease significantly where the high-speed flows are registered. Based on an AE index superposed epoch study, the flapping motions prefer to appear during the substorm expansion phase, although a considerable number of events without any electrojet and auroral activity were also observed. We also present statistical distributions of other parameters and briefly discuss what could be possible mechanisms to generate the flapping motions.
The effect of ion motion on rotating magnetic field current drive
The effect of ion motion on rotating magnetic field (RMF) current drive in field reversed configurations is studied using a fully two-dimensional numerical code that solves the two fluid equations with massless electrons and constant uniform temperature. The ion momentum equation includes viscosity and collisions with neutrals, which remain fixed. The electrons are described with an Ohm's law that includes the Hall and pressure gradient terms. For full penetration of the RMF, ion spin-up due to collisions with electrons reduces the current drive efficiency and a large fraction of neutrals is needed to prevent the ions from acquiring high azimuthal velocities. For conditions that would result in incomplete penetration with the fixed ion model, ion rotation and variable density can facilitate the penetration of the RMF, thus increasing the efficiency. The rotation modifies the density profile and can trigger rotational instabilities
A new description of nuclear rotational motion in terms of the intrinsic pair mode
A new method describing nuclear rotational motion microscopically is proposed. We extract the rotational Hamiltonian by introducing the intrinsic pair modes that commute with the rotational mode. As a result, the rotational mode is not treated as a zero energy mode, in contrast with the case of the conventional RPA formalism, so that we circumvent the difficulty related with infrared divergence. The wave function is constructed by applying an angular momentum projection to each intrinsic state. Without resorting to numerical integration for the projection, we calculate the matrix elements analytically under a certain approximation. Numerical calculations are carried out to illustrate the applicability of our method, and they show that our method works well. (author)
Microscopic description of large amplitude collective motion in the nuclear astrophysics context
Lacroix, Denis; Scamps, Guillaume; Simenel, Cédric
2015-01-01
In the last 10 years, we have observed an important increase of interest in the application of time-dependent energy density functional theory (TD-EDF). This approach allows to treat nuclear structure and nuclear reaction from small to large amplitude dynamics in a unified framework. The possibility to perform unrestricted three-dimensional simulations using state of the art effective interactions has opened new perspectives. In the present article, an overview of applications where the predictive power of TD-EDF has been benchmarked is given. A special emphasize is made on processes that are of astrophysical interest. Illustrations discussed here include giant resonances, fission, binary and ternary collisions leading to fusion, transfer and deep inelastic processes.
A fast quaternion-based orientation optimizer via virtual rotation for human motion tracking.
Lee, Jung Keun; Park, Edward J
2009-05-01
For real-time ambulatory human motion tracking with low-cost inertial/magnetic sensors, a computationally efficient and robust algorithm for estimating orientation is critical. This paper presents a quaternion-based orientation optimizer for tracking human body motion, using triaxis rate gyro, accelerometer, and magnetometer signals. The proposed optimizer uses a Gauss-Newton (G-N) method for finding the best-fit quaternion. In order to decrease the computing time, the optimizer is formulated using a virtual rotation concept that allows very fast quaternion updates compared to the conventional G-N method. In addition, to guard against the effects of fast body motions and temporary ferromagnetic disturbances, a situational measurement vector selection procedure is adopted in conjunction with the G-N optimizer. The accuracy of orientation estimates is validated experimentally, using arm motion trials. PMID:19473934
The design basis for earthquake ground motion is given by the peak ground acceleration, response spectrfal shapes for various damping values and the time history of ground motion in horizontal and vertical directions. The time history is required to be compatible with a specified design response spectrum. The course of having treated this problem in the past is outlined. Power spectral density functions (PSDF) require the explicit definition of the duration of motion, but fourier amplitude spectrum (FAS) treat the data as such. Whatever way the target PSDF or FAS was arrived at, its consistency with the specified response spectrum should be assured. Accordingly, it appears prudent to select a suitable data base and derive the target response spectrum and the FAS. In this paper, an algorithm for generating the accelerograms compatible with a specified response spectrum and a FAS is described. The compatibility criteria, the methods of generating algorithms based on response spectrum conpatibility, the inversion of FAS and the combination of response spectrum compatibility and the inversion of FAS, and the numerical results are reported. (K.I.)
Motion sickness susceptibility during rotation at 30 rpm in free-fall parabolic flight
Graybiel, A.
1979-01-01
To make comparisons with experimental motion sickness susceptibility in Skylab missions, subjects were tested during free fall in parabolic flight and in ground-based simulation tests. They were rotated at 30 rpm in a rotating litter chair (RLC) with head fixed, head swiveling left-to-right, or with 90 degree forward and return head and body movements. Stressful accelerations similar to those in the Skylab RLC were generated only in the tests aloft, where subjects who made 'forward and return' movements (generating cross-coupled angular accelerations) were substantially more prone to motion sickness than those with either head fixed or head swiveling left-to-right. However, with head swiveling, susceptibility was slightly higher in the laboratory than aloft.
Evidence for rotational motions in the feet of a quiescent solar prominence
Suárez, D. Orozco; Ramos, A. Asensio; Bueno, J. Trujillo
2012-01-01
We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the He I 1083.0 nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the slit of the spectrograph almost parallel to the solar limb and crossing two feet of an intermediate size, quiescent hedgerow prominence. The data sh...
Quantification of mouse in vivo whole-body vibration amplitude from motion-blur using x-ray imaging
Musculoskeletal effects of whole-body vibration on animals and humans have become an intensely studied topic recently, due to the potential of applying this method as a non-pharmacological therapy for strengthening bones. It is relatively easy to quantify the transmission of whole-body mechanical vibration through the human skeletal system using accelerometers. However, this is not the case for small-animal pre-clinical studies because currently available accelerometers have a large mass, relative to the mass of the animals, which causes the accelerometers themselves to affect the way vibration is transmitted. Additionally, live animals do not typically remain motionless for long periods, unless they are anesthetized, and they are required to maintain a static standing posture during these studies. These challenges provide the motivation for the development of a method to quantify vibrational transmission in small animals. We present a novel imaging technique to quantify whole-body vibration transmission in small animals using 280 μm diameter tungsten carbide beads implanted into the hind limbs of mice. Employing time-exposure digital x-ray imaging, vibrational amplitude is quantified based on the blurring of the implanted beads caused by the vibrational motion. Our in vivo results have shown this technique is capable of measuring vibration amplitudes as small as 0.1 mm, with precision as small as ±10 μm, allowing us to distinguish differences in the transmitted vibration at different locations on the hindlimbs of mice. (paper)
Quantification of mouse in vivo whole-body vibration amplitude from motion-blur using x-ray imaging
Hu, Zhengyi; Welch, Ian; Yuan, Xunhua; Pollmann, Steven I.; Nikolov, Hristo N.; Holdsworth, David W.
2015-08-01
Musculoskeletal effects of whole-body vibration on animals and humans have become an intensely studied topic recently, due to the potential of applying this method as a non-pharmacological therapy for strengthening bones. It is relatively easy to quantify the transmission of whole-body mechanical vibration through the human skeletal system using accelerometers. However, this is not the case for small-animal pre-clinical studies because currently available accelerometers have a large mass, relative to the mass of the animals, which causes the accelerometers themselves to affect the way vibration is transmitted. Additionally, live animals do not typically remain motionless for long periods, unless they are anesthetized, and they are required to maintain a static standing posture during these studies. These challenges provide the motivation for the development of a method to quantify vibrational transmission in small animals. We present a novel imaging technique to quantify whole-body vibration transmission in small animals using 280 μm diameter tungsten carbide beads implanted into the hind limbs of mice. Employing time-exposure digital x-ray imaging, vibrational amplitude is quantified based on the blurring of the implanted beads caused by the vibrational motion. Our in vivo results have shown this technique is capable of measuring vibration amplitudes as small as 0.1 mm, with precision as small as ±10 μm, allowing us to distinguish differences in the transmitted vibration at different locations on the hindlimbs of mice.
Three-dimensional organization of vestibular related eye movements to rotational motion in pigeons
Dickman, J. D.; Beyer, M.; Hess, B. J.
2000-01-01
During rotational motions, compensatory eye movement adjustments must continually occur in order to maintain objects of visual interest as stable images on the retina. In the present study, the three-dimensional organization of the vestibulo-ocular reflex in pigeons was quantitatively examined. Rotations about different head axes produced horizontal, vertical, and torsional eye movements, whose component magnitude was dependent upon the cosine of the stimulus axis relative to the animal's visual axis. Thus, the three-dimensional organization of the VOR in pigeons appears to be compensatory for any direction of head rotation. Frequency responses of the horizontal, vertical, and torsional slow phase components exhibited high pass filter properties with dominant time constants of approximately 3 s.
Purpose: To develop a control system to correct both translational and rotational head motion deviations in real-time during frameless stereotactic radiosurgery (SRS). Methods: A novel feedback control with a feed-forward algorithm was utilized to correct for the coupling of translation and rotation present in serial kinematic robotic systems. Input parameters for the algorithm include the real-time 6DOF target position, the frame pitch pivot point to target distance constant, and the translational and angular Linac beam off (gating) tolerance constants for patient safety. Testing of the algorithm was done using a 4D (XY Z + pitch) robotic stage, an infrared head position sensing unit and a control computer. The measured head position signal was processed and a resulting command was sent to the interface of a four-axis motor controller, through which four stepper motors were driven to perform motion compensation. Results: The control of the translation of a brain target was decoupled with the control of the rotation. For a phantom study, the corrected position was within a translational displacement of 0.35 mm and a pitch displacement of 0.15° 100% of the time. For a volunteer study, the corrected position was within displacements of 0.4 mm and 0.2° over 98.5% of the time, while it was 10.7% without correction. Conclusions: The authors report a control design approach for both translational and rotational head motion correction. The experiments demonstrated that control performance of the 4D robotic stage meets the submillimeter and subdegree accuracy required by SRS
Liu, Xinmin; Belcher, Andrew H.; Grelewicz, Zachary; Wiersma, Rodney D., E-mail: rwiersma@uchicago.edu [Department of Radiation and Cellular Oncology, The University of Chicago, Chicago, Illinois 60637 (United States)
2015-06-15
Purpose: To develop a control system to correct both translational and rotational head motion deviations in real-time during frameless stereotactic radiosurgery (SRS). Methods: A novel feedback control with a feed-forward algorithm was utilized to correct for the coupling of translation and rotation present in serial kinematic robotic systems. Input parameters for the algorithm include the real-time 6DOF target position, the frame pitch pivot point to target distance constant, and the translational and angular Linac beam off (gating) tolerance constants for patient safety. Testing of the algorithm was done using a 4D (XY Z + pitch) robotic stage, an infrared head position sensing unit and a control computer. The measured head position signal was processed and a resulting command was sent to the interface of a four-axis motor controller, through which four stepper motors were driven to perform motion compensation. Results: The control of the translation of a brain target was decoupled with the control of the rotation. For a phantom study, the corrected position was within a translational displacement of 0.35 mm and a pitch displacement of 0.15° 100% of the time. For a volunteer study, the corrected position was within displacements of 0.4 mm and 0.2° over 98.5% of the time, while it was 10.7% without correction. Conclusions: The authors report a control design approach for both translational and rotational head motion correction. The experiments demonstrated that control performance of the 4D robotic stage meets the submillimeter and subdegree accuracy required by SRS.
Tursunov, Arman; Stuchlík, Zdeněk; Kološ, Martin
2016-04-01
We study the motion of charged particles in the field of a rotating black hole immersed into an external asymptotically uniform magnetic field, focusing on the epicyclic quasicircular orbits near the equatorial plane. Separating the circular orbits into four qualitatively different classes according to the sign of the canonical angular momentum of the motion and the orientation of the Lorentz force, we analyze the circular orbits using the so-called force formalism. We find the analytical solutions for the radial profiles of velocity, specific angular momentum, and specific energy of the circular orbits in dependence on the black-hole dimensionless spin and the magnetic field strength. The innermost stable circular orbits are determined for all four classes of the circular orbits. The stable circular orbits with an outward-oriented Lorentz force can extend to radii lower than the radius of the corresponding photon circular geodesic. We calculate the frequencies of the harmonic oscillatory motion of the charged particles in the radial and vertical directions related to the equatorial circular orbits and study the radial profiles of the radial, ωr; vertical, ωθ; and orbital, ωϕ, frequencies, finding significant differences in comparison to the epicyclic geodesic circular motion. The most important new phenomenon is the existence of toroidal charged particle epicyclic motion with ωr˜ωθ≫ωϕ that could occur around retrograde circular orbits with an outward-oriented Lorentz force. We demonstrate that for the rapidly rotating black holes the role of the "Wald induced charge" can be relevant.
A test particle model is used to study the motion of ions specularly reflected off a shock in the presence of large-amplitude, monochromatic, transverse MHD waves. The characteristics of the motion depend on the frequency, wavelength, phase, and amplitude of the wave that is being convected into the shock. For low wave frequencies and long wavelengths (ω'> ion gyroradius), the ion motion depends only upon theta/sub B/n(phi0), the instantaneous angle between the total magnetic field at the shock (ambient+wave) and the shock normal. For high wave frequencies and short wavelengths (ω'>>ion gyrofrequency, lambda0, the angle between the ambient magnetic field and the shock normal. For intermediate frequencies and wavelengths, including those of interest in the region upstream from the earth's bow shock (ω'approx.ion gyrofrequency, lambdaapprox.ion gyroradius), no simple theta/sub B/n0 or theta/sub B/n(phi0) criterion for the ion motion is found. For example, at intermediate frequencies, the motion depends both on theta/sub B/n(phi0) and theta/sub B/n0 as well as upon b/B, the ratio of the wave amplitude to ambient magnetic field strength. In general, the presence of upstream waves inhibits the escape of specularly reflected ions from the shock, the effect being greatest when the wave amplitude is large
Basri, Gibor; Batalha, Natalie; Gilliland, Ronald L; Jenkins, Jon; Borucki, William J; Koch, David; Caldwell, Doug; Dupree, Andrea K; Latham, David W; Marcy, Geoffrey W; Meibom, Soeren; Howell, Steve; Brown, Tim
2010-01-01
We provide an overview of stellar variability in the first quarter of data from the Kepler mission. The intent of this paper is to examine the entire sample of over 150,000 target stars for periodic behavior in their lightcurves, and relate this to stellar characteristics. These data constitute an unprecedented study of stellar variability given its great precision and complete time coverage (with a half hour cadence). Because the full Kepler pipeline is not currently suitable for a study of stellar variability of this sort, we describe our procedures for treating the "raw" pipeline data. About half of the total sample exhibits convincing periodic variability up to two weeks, with amplitudes ranging from differential intensity changes less than 10^{-4} up to more than 10 percent. K and M dwarfs have a greater fraction of period behavior than G dwarfs. The giants in the sample have distinctive quasi-periodic behavior, but are not periodic in the way we define it. Not all periodicities are due to rotation, and ...
A reciprocating motion-driven rotation mechanism for the ATP synthase.
Liu, Jiafeng; Fu, Xinmiao; Chang, Zengyi
2016-01-01
The ATP synthase (having a typical subunit composition of α3β3γδεab2c8-15) employs an intriguing rotary mechanism for the generation of ATP from ADP and Pi, using energy stored in a transmembrane proton gradient. The conventional rotary model, although being generally accepted, remains difficult to explain certain experimental observations. Here we propose an alternative rotary model for the ATP synthase such that what rotates is the catalytic α3β3 cylinder rather than the central stalk and the membrane-embedded c-ring. Specifically, the membrane translocation of protons would induce a cycled conformational change in the c-ring, leading to a reciprocating motion of the attached central stalk, which in turn drives the unidirectional rotation of the α3β3 cylinder. Such a reciprocating motion-driven rotation mechanism is somehow analogous to the working mechanism of a retractable click ballpoint pen. Our new model not only explains the experimental observations that have been difficult to reconcile with the conventional model but also avoids its theoretical illogicality. PMID:26718355
Giancarlo Guizzardi
2015-06-01
Full Text Available Introduction. The IntraSPINE is a new interlaminar device that has been proposed with the aim to decompress the spinal canal without reducing the extension motion. The purpose of this study was therefore to evaluate the biomechanical behavior of L4-L5 spinal units implanted with this interlaminar device, in terms of ranges of motion, intradiscal pressure, and centers of rotation. Material and Methods. Six human lumbar spines were harvested within 10 days after death. A specific spine testing device was used to apply moments up to 10 Nm in flexion-extension, lateral bending (left-right flexion and left-right axial rotation (torsion, with measurement of vertebral 3D motion and of intervertebral disc pressure. Protocol was repeated for each specimen in 5 configurations: intact specimen; after L4-L5 bilateral medial hemifacetectomy and both yellow ligament resection; after implantation of the interlaminar device at the L4-L5 level; after removal of the L4-L5 supraspinous ligament, resection of the posterior third of the disc and addition of an artificial ligament; after device and artificial ligament removal. Results. The implant reduced increases in segmental flexion seen following injury particularly when applied with the artificial ligament. Intradiscal pressure reduced following application of the implant without reducing extension range. A small posterior shift of the Mean Centers of Rotation (MCR was noticed after instrumentation. Torsion and lateral bending range was unaffected by the interlaminar device. Conclusion. This biomechanical study yields a better understanding of this interlaminar implant effect. A large clinical trial with follow-up would be required to evaluate and confirm in vivo the observed in vitro biomechanical behavior of the device.
Sergey PLOTNIKOV
2014-09-01
Full Text Available The simulation from the motion of flat particle revealed that the fall depends on the height of the drop, the thickness and density of the particles and does not depend on its length and width. The drop in air is about 20% longer than in vacuum. During orientation from angular particles the velocity of rotating particles with a length of 150mm is reduced by 18%, for particles with a length of 75mm by 12%. This reduction increases linearly with decreasing density of particles. A velocity field acting on the particle in the fall and rotation was presented. The results of the study prove the possibility to reduce the scatter of the particles during the mat's formation, that in turns can increase the board’s bending strength.
On the relative rotational motion between rigid fibers and fluid in turbulent channel flow
In this study, the rotation of small rigid fibers relative to the surrounding fluid in wall-bounded turbulence is examined by means of direct numerical simulations coupled with Lagrangian tracking. Statistics of the relative (fiber-to-fluid) angular velocity, referred to as slip spin in the present study, are evaluated by modelling fibers as prolate spheroidal particles with Stokes number, St, ranging from 1 to 100 and aspect ratio, λ, ranging from 3 to 50. Results are compared one-to-one with those obtained for spherical particles (λ = 1) to highlight effects due to fiber length. The statistical moments of the slip spin show that differences in the rotation rate of fibers and fluid are influenced by inertia, but depend strongly also on fiber length: Departures from the spherical shape, even when small, are associated with an increase of rotational inertia and prevent fibers from passively following the surrounding fluid. An increase of fiber length, in addition, decouples the rotational dynamics of a fiber from its translational dynamics suggesting that the two motions can be modelled independently only for long enough fibers (e.g., for aspect ratios of order ten or higher in the present simulations)
Piezoelectric energy harvesting provides a means to harvest the ambient kinetic energy (e.g., vibrations and rotations) of structures for conversion into usable electricity. The technique can be employed to provide power sources for wireless sensors and low-power devices. Most energy harvesting devices developed to date operate most efficiently within a narrow bandwidth because they are resonance-frequency-based designs, although several tunable techniques have been proposed to broaden the efficient frequency range of energy harvesting. However, most efforts have focused on harvesting vibration energy rather than rotational energy. This paper presents the results of a comprehensive design analysis and experimental tests of a passive self-tuning piezoelectric composite cantilever beam for harvesting energy from rotational motion. The piezoelectric beam harvester is mounted on a rotating axis in the radial direction so that the tensile stress induced by the centrifugal force effectively stiffens the beam to passively tune the resonance frequency. A calculation procedure based on a finite element method is developed to analyze the self-frequency-tuning piezoelectric energy harvester, and the results are compared with those obtained from an analytic beam model. The design parameters for the self-tuning characteristics are identified and discussed. Experimental results verify the frequency-tuning energy harvesting behavior and show improved performances for the voltage and power outputs in the bandwidth. (papers)
On the relative rotational motion between rigid fibers and fluid in turbulent channel flow
Marchioli, C. [Department of Electrical, Management and Mechanical Engineering, University of Udine, 33100 Udine (Italy); Zhao, L., E-mail: lihao.zhao@ntnu.no [Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Andersson, H. I. [Department of Electrical, Management and Mechanical Engineering, University of Udine, 33100 Udine (Italy); Department of Energy and Process Engineering, Norwegian University of Science and Technology, 7491 Trondheim (Norway)
2016-01-15
In this study, the rotation of small rigid fibers relative to the surrounding fluid in wall-bounded turbulence is examined by means of direct numerical simulations coupled with Lagrangian tracking. Statistics of the relative (fiber-to-fluid) angular velocity, referred to as slip spin in the present study, are evaluated by modelling fibers as prolate spheroidal particles with Stokes number, St, ranging from 1 to 100 and aspect ratio, λ, ranging from 3 to 50. Results are compared one-to-one with those obtained for spherical particles (λ = 1) to highlight effects due to fiber length. The statistical moments of the slip spin show that differences in the rotation rate of fibers and fluid are influenced by inertia, but depend strongly also on fiber length: Departures from the spherical shape, even when small, are associated with an increase of rotational inertia and prevent fibers from passively following the surrounding fluid. An increase of fiber length, in addition, decouples the rotational dynamics of a fiber from its translational dynamics suggesting that the two motions can be modelled independently only for long enough fibers (e.g., for aspect ratios of order ten or higher in the present simulations)
Ring-Puckering Motion in 1-Chloro-cyclopentene: Rotational Spectrum and ab InitioCalculations
Caminati, Walther; Danieli, Roberto; Fantoni, Adolfo C.; Lopez, Juan C.
1997-01-01
The rotational spectra of 35Cl and 37Cl 1-chloro-cyclopentene have been investigated in the frequency range 26-40 GHz. The inversion splittings due to the ring-puckering motion have been determined to be 42320(10) and 42270(10) MHz for the two isotopomers, respectively. Four more vibrational states have been analyzed for the most abudant ( 35Cl) species. The barrier hindering the ring-puckering has been evaluated. According to the ab initiocalculations, it is lower than that in cyclopentene.
Linear motion and rotation characteristics of YBCO bulk using exciting coils
A superconducting actuator with multiple motions is proposed and experimentally investigated for the development of microelectrical machines. The disk-shaped YBCO bulk was located above the electromagnets and cooled down in the field-cooling method, which enabled the flux pinning. The YBCO bulk superconductor was driven in vertical, horizontal and/or self-rotation by PC-controlled coil currents using multiple electromagnets. The most suitable levitation stability was obtained when we used four electromagnets and NNSS trapped field type. It was confirmed that the levitation force and horizontal moving force strongly depended on the coil current and the air gap length, respectively
Soyka, Florian; Giordano, Paolo Robuffo; Barnett-Cowan, Michael; Heinrich H Bülthoff
2012-01-01
Understanding the dynamics of vestibular perception is important, for example, for improving the realism of motion simulation and virtual reality environments or for diagnosing patients suffering from vestibular problems. Previous research has found a dependence of direction discrimination thresholds for rotational motions on the period length (inverse frequency) of a transient (single cycle) sinusoidal acceleration stimulus. However, self-motion is seldom purely sinusoidal, and up to now, no...
Andersen, J; Heimdal, J; Wugt Larsen, R
2015-10-01
The far-infrared absorption spectra have been recorded for hydrogen-bonded complexes of water with methanol and t-butanol embedded in cryogenic neon matrices at 2.8 K. The partial isotopic substitution of individual subunits enabled by a dual inlet deposition procedure provides for the first time unambiguous assignments of the intermolecular high-frequency out-of-plane and low-frequency in-plane donor OH librational modes for mixed alcohol-water complexes. The vibrational assignments confirm directly that water acts as the hydrogen bond donor in the most stable mixed complexes and the tertiary alcohol is a superior hydrogen bond acceptor. The class of large-amplitude donor OH librational motion is shown to account for up to 5.1 kJ mol(-1) of the destabilizing change of vibrational zero-point energy upon intermolecular OHO hydrogen bond formation. The experimental findings are supported by complementary electronic structure calculations at the CCSD(T)-F12/aug-cc-pVTZ level of theory. PMID:26304774
Lew, Ben W P; Zhou, Yifan; Schneider, Glenn; Burgasser, Adam J; Karalidi, Theodora; Yang, Hao; Marley, Mark S; Cowan, N B; Bedin,; R., L; Metchev, Stanimir A; Radigan, Jacqueline; Lowrance, Patrick J
2016-01-01
Condensate clouds fundamentally impact the atmospheric structure and spectra of exoplanets and brown dwarfs but the connections between surface gravity, cloud structure, dust in the upper atmosphere, and the red colors of some brown dwarfs remain poorly understood. Rotational modulations enable the study of different clouds in the same atmosphere, thereby providing a method to isolate the effects of clouds. Here we present the discovery of high peak-to-peak amplitude (8%) rotational modulations in a low-gravity, extremely red (J-Ks=2.55) L6 dwarf WISEP J004701.06+680352.1 (W0047). Using the Hubble Space Telescope (HST) time-resolved grism spectroscopy we find a best-fit rotational period (13.20$\\pm$0.14 hours) with a larger amplitude at 1.1 micron than at 1.7 micron. This is the third largest near-infrared variability amplitude measured in a brown dwarf, demonstrating that large-amplitude variations are not limited to the L/T transition but are present in some extremely red L-type dwarfs. We report a tentativ...
EVIDENCE FOR ROTATIONAL MOTIONS IN THE FEET OF A QUIESCENT SOLAR PROMINENCE
We present observational evidence of apparent plasma rotational motions in the feet of a solar prominence. Our study is based on spectroscopic observations taken in the He I 1083.0 nm multiplet with the Tenerife Infrared Polarimeter attached to the German Vacuum Tower Telescope. We recorded a time sequence of spectra with 34 s cadence placing the slit of the spectrograph almost parallel to the solar limb and crossing two feet of an intermediate size, quiescent hedgerow prominence. The data show opposite Doppler shifts, ±6 km s–1, at the edges of the prominence feet. We argue that these shifts may be interpreted as prominence plasma rotating counterclockwise around the vertical axis to the solar surface as viewed from above. The evolution of the prominence seen in EUV images taken with the Solar Dynamics Observatory provided us with clues to interpret the results as swirling motions. Moreover, time-distance images taken far from the central wavelength show plasma structures moving parallel to the solar limb with velocities of about 10-15 km s–1. Finally, the shapes of the observed intensity profiles suggest the presence of, at least, two components at some locations at the edges of the prominence feet. One of them is typically Doppler shifted (up to ∼20 km s–1) with respect to the other, thus suggesting the existence of supersonic counter-streaming flows along the line of sight.
Almeida, Gabriel Peixoto Leão; de Souza, Vivian Lima; Sano, Saulo Sadao; Saccol, Michele Forgiarini; Cohen, Moisés
2012-06-01
This study compared hip rotation range of motion in judo athletes with and without a history of low back pain. Forty-two athletes (22 males) were divided into two groups: 21 with history of low back pain (HLBP) and 21 without history of low back pain (Control). Internal and external hip rotation range of motion in active and passive movement were measured using computed photogrammetry. The HLBP group exhibited a significant reduction in active internal rotation (27.5 ± 6.5°vs 38.2 ± 6.5°), active total rotation (80.1 ± 9.5°vs 87.4 ± 7.9°) of the non-dominant limb (P judo athletes with a history of low back pain exhibit deficits in hip rotation and greater asymmetry between limbs. PMID:22281524
Reconstructing plate-motion changes in the presence of finite-rotations noise.
Iaffaldano, Giampiero; Bodin, Thomas; Sambridge, Malcolm
2012-01-01
Understanding lithospheric plate motions is of paramount importance to geodynamicists. Much effort is going into kinematic reconstructions featuring progressively finer temporal resolution. However, the challenge of precisely identifying ocean-floor magnetic lineations, and uncertainties in geomagnetic reversal timescales result in substantial finite-rotations noise. Unless some type of temporal smoothing is applied, the scenario arising at the native temporal resolution is puzzling, as plate motions vary erratically and significantly over short periods (<1 Myr). This undermines our ability to make geodynamic inferences, as the rates at which forces need to be built upon plates to explain these kinematics far exceed the most optimistic estimates. Here we show that the largest kinematic changes reconstructed across the Atlantic, Indian and South Pacific ridges arise from data noise. We overcome this limitation using a trans-dimensional hierarchical Bayesian framework. We find that plate-motion changes occur on timescales no shorter than a few million years, yielding simpler kinematic patterns and more plausible dynamics. PMID:22948830
Wang, Song; Song, Jian; Liao, Zhenhua; Feng, Pingfa; Liu, Weiqiang
2016-06-01
The wear behaviors of a ball-on-socket (UHMWPE-on-Ti6Al4V) artificial cervical disc were studied with 1.5MC (million cycles) wear simulation under single flexion/extension and axial rotation motion and their composite motion. The wear rates, wear traces, and contact stress were analyzed and contrasted based on mass loss, optical microscopy and SEM as well as 3D profilometer, and ANSYS software, respectively. A much higher wear rate and more severe wear scars appeared under multi-directional motion. Flexion/extension motion of 7.5° lead to more severe wear than that under axial rotation motion of 4°. The above results were closely related to the contact compression stress and shear stress. The wear surface in FE motion showed typical linear wear scratches while revealing obvious arc-shaped wear tracks in AR motion. However, the central zone of both ball and socket components revealed more severe wear tracks than that in the edge zone under these two different motions. The dominant wear mechanism was plowing/scratching and abrasive wear as well as a little oxidation wear for the titanium socket while it was scratching damage with adhesive wear and fatigue wear due to plastic deformation under cyclic load and motion profiles for the UHMWPE ball. PMID:27040218
Modeling and adaptive motion/force tracking for ver tical wheel on rotating table
Zhongcai Zhang; Yuqiang Wu; Wei Sun
2015-01-01
This paper is devoted to the problem of modeling and adaptive motion/force tracking for a class of nonholonomic dy-namic systems with affine constraints (NDSAC): a vertical wheel on a rotating table. Prior to the development of tracking control er, the dynamic model of the wheel in question is derived in a meticu-lous manner. A continuously differentiable friction model is also considered in the modeling. By exploiting the inherent cascade interconnected structure of the wheel dynamics, an adaptive mo-tion/force tracking control er is presented guaranteeing that the trajectory tracking errors asymptotical y converge to zero while the contact force tracking errors can be made smal enough by tuning design parameters. Simulation results are provided to validate the effectiveness of the proposed tracking methodology.
Study of Stability of Rotational Motion of Spacecraft with Canonical Variables
William Reis Silva
2012-01-01
Full Text Available This work aims to analyze the stability of the rotational motion of artificial satellites in circular orbit with the influence of gravity gradient torque, using the Andoyer variables. The used method in this paper to analyze stability is the Kovalev-Savchenko theorem. This method requires the reduction of the Hamiltonian in its normal form up to fourth order by means of canonical transformations around equilibrium points. The coefficients of the normal Hamiltonian are indispensable in the study of nonlinear stability of its equilibrium points according to the three established conditions in the theorem. Some physical and orbital data of real satellites were used in the numerical simulations. In comparison with previous work, the results show a greater number of equilibrium points and an optimization in the algorithm to determine the normal form and stability analysis. The results of this paper can directly contribute in maintaining the attitude of artificial satellites.
Investigation of Pendulum Structures for Rotational Energy Harvesting from Human Motion
Ylli, K.; Hoffmann, D.; Willmann, A.; Folkmer, B.; Manoli, Y.
2015-12-01
Energy Harvesting from human motion as a means of powering body-worn devices has been in the focus of research groups for several years now. This work presents a rotational inductive energy harvester that can generate a sufficient amount of energy during normal walking to power small electronic systems. Three pendulum structures and their geometrical parameters are investigated in detail through a system model and system simulations. Based on these results a prototype device is fabricated. The masses and angles between pendulum arms can be changed for the experiments. The device is tested under real-world conditions and generates an average power of up to 23.39 mW across a resistance equal to the coil resistance of the optimal pendulum configuration. A regulated power output of the total system including power management of 3.3 mW is achieved.
Relegation of the proper rotation in the orbital-attitude motion of a spacecraft
Arribas, Mercedes; Elipe, Antonio
An analytical approach is taken to study the attitude of a spacecraft on an orbit around a planet assimilated to a mass point. In the Hamiltonian representing this dynamical system, we identify the principal term (of order 0) as made of two parts: the part describing the motion of the center of mass of the satellite about the planet is expressed in terms of the Whittaker variables, and the part accounting for the rotation of the satellite about its center of mass in the absence of external forces which is expressed in terms of the Serret-Andoyer variables. We propose to build a Lie transformation to remove the angle g from the potential of the perturbation by applying the 'relegation of the node' technique.
Motion of beads in an oscillatory rotating fluid: micro-bead-beating
Nadim, Ali; Sterling, James; Doebler, Robert
2008-11-01
One method for mechanical lysis of biological cells and spores is to mix them with a suspension of beads and vigorously ``shake'' the mixture. The precise mechanisms of lysis are not understood but lysis is thought to result from collisions between the beads and the cells and the associated stresses exerted on the cells. For instance, in the micro-bead-beater^TM instrument from Claremont BioSolutions LLC (Upland, CA), the ``shaking'' occurs when a small cartridge filled with a mixture of cells/spores and 100-micron beads is driven at high frequencies in a small arc trajectory. In this presentation, we describe our initial modeling effort aimed at understanding this system via analysis of the trajectories of beads within such an instrument. The equations governing the motion of non-neutrally-buoyant spherical beads in an oscillatory rotating flow are derived and analyzed numerically. The resulting trajectories are found to be quite complex and very different from those in a steadily rotating fluid. A catalog of possible trajectories at various values of the governing dimensionless parameters is presented.
Real World Testing Of A Piezoelectric Rotational Energy Harvester For Human Motion
Harvesting energy from human motion is challenging because the frequencies are generally low and random compared to industrial machinery that vibrates at much higher frequencies. One of the most promising and popular strategies to overcome this is frequency up-conversion. The transducing element is actuated at its optimal frequency of operation, higher than the source excitation frequency, through some kind of catch and release mechanism. This is beneficial for efficient power generation. Such devices have now been investigated for a few years and this paper takes a previously introduced piezoelectric rotational harvester, relying on beam plucking for the energy conversion, to the next step by testing the device during a half marathon race. The prototype and data acquisition system are described in detail and the experimental results presented. A comparison of the input excitation, based on an accelerometer readout, and the output voltage of the piezoelectric beam, recorded at the same time, confirm the successful implementation of the system. For a device functional volume of 1.85 cm3, a maximum power output of 7 μW was achieved when the system was worn on the upper arm. However, degradation of the piezoelectric material meant that the performance dropped rapidly from this initial level; this requires further research. Furthermore, the need for intermediate energy storage solutions is discussed, as human motion harvesters only generate power as long as the wearer is actually moving
Real World Testing Of A Piezoelectric Rotational Energy Harvester For Human Motion
Pillatsch, P.; Yeatman, E. M.; Holmes, A. S.
2013-12-01
Harvesting energy from human motion is challenging because the frequencies are generally low and random compared to industrial machinery that vibrates at much higher frequencies. One of the most promising and popular strategies to overcome this is frequency up-conversion. The transducing element is actuated at its optimal frequency of operation, higher than the source excitation frequency, through some kind of catch and release mechanism. This is beneficial for efficient power generation. Such devices have now been investigated for a few years and this paper takes a previously introduced piezoelectric rotational harvester, relying on beam plucking for the energy conversion, to the next step by testing the device during a half marathon race. The prototype and data acquisition system are described in detail and the experimental results presented. A comparison of the input excitation, based on an accelerometer readout, and the output voltage of the piezoelectric beam, recorded at the same time, confirm the successful implementation of the system. For a device functional volume of 1.85 cm3, a maximum power output of 7 μW was achieved when the system was worn on the upper arm. However, degradation of the piezoelectric material meant that the performance dropped rapidly from this initial level; this requires further research. Furthermore, the need for intermediate energy storage solutions is discussed, as human motion harvesters only generate power as long as the wearer is actually moving.
Nonlinear resonance phenomena in the solar system, including commensurability between the axial and orbital motions of the planets has drawn the attention of researchers. The resource in the motion of Venus has been discussed: at each inferior conjunction with the earth the same side of Venus is turned toward the earth. This work examines the evolution of the translational-rotational motion of a viscoelastic planet of Kelvin-Voigt material moving in the field of two attracting points. A model of the sun-Venus-Earth system is constructed. An averaging scheme is used to investigate the resonance modes in two-frequency oscillatory systems
Mental rotation meets the motion aftereffect: the role of hV5/MT+ in visual mental imagery
Seurinck, Ruth; de Lange, Floris P.; Achten, Eric; Vingerhoets, Guy
2011-01-01
A growing number of studies show that visual mental imagery recruits the same brain areas as visual perception. Although the necessity of hV5/MT+ for motion perception has been revealed by means of TMS, its relevance for motion imagery remains unclear. We induced a direction-selective adaptation in hV5/MT+ by means of an MAE while subjects performed a mental rotation task that elicits imagined motion. We concurrently measured behavioral performance and neural activity with fMRI, enabling us t...
Liang, Wenfeng; Zhang, Ke; Yang, Xieliu; Liu, Lianqing; Yu, Haibo; Zhang, Weijing
2015-01-01
In this paper, the translational motion and self-rotational behaviors of the Raji cells, a type of B-cell lymphoma cell, in an optically induced, non-rotational, electric field have been characterized by utilizing a digitally programmable and optically activated microfluidics chip with the assistance of an externally applied AC bias potential. The crossover frequency spectrum of the Raji cells was studied by observing the different linear translation responses of these cells to the positive and negative optically induced dielectrophoresis force generated by a projected light pattern. This digitally projected spot served as the virtual electrode to generate an axisymmetric and non-uniform electric field. Then, the membrane capacitance of the Raji cells could be directly measured. Furthermore, Raji cells under this condition also exhibited a self-rotation behavior. The repeatable and controlled self-rotation speeds of the Raji cells to the externally applied frequency and voltage were systematically investigated and characterized via computer-vision algorithms. The self-rotational speed of the Raji cells reached a maximum value at 60 kHz and demonstrated a quadratic relationship with respect to the applied voltage. Furthermore, optically projected patterns of four orthogonal electrodes were also employed as the virtual electrodes to manipulate the Raji cells. These results demonstrated that Raji cells located at the center of the four electrode pattern could not be self-rotated. Instead any Raji cells that deviated from this center area would also self-rotate. Most importantly, the Raji cells did not exhibit the self-rotational behavior after translating and rotating with respect to the center of any two adjacent electrodes. The spatial distributions of the electric field generated by the optically projected spot and the pattern of four electrodes were also modeled using a finite element numerical simulation. These simulations validated that the electric field
Communication: creation of molecular vibrational motions via the rotation-vibration coupling
Shu, Chuan-Cun; Henriksen, Niels Engholm
2015-01-01
Building on recent advances in the rotational excitation of molecules, we show how the effect of rotation-vibration coupling can be switched on in a controlled manner and how this coupling unfolds in real time after a pure rotational excitation. We present the first examination of the vibrational...... to a laser-induced breakdown of the adiabatic approximation for rotation-vibration coupling....
Marko Wilke
Full Text Available Subject motion has long since been known to be a major confound in functional MRI studies of the human brain. For resting-state functional MRI in particular, data corruption due to motion artefacts has been shown to be most relevant. However, despite 6 parameters (3 for translations and 3 for rotations being required to fully describe the head's motion trajectory between timepoints, not all are routinely used to assess subject motion. Using structural (n = 964 as well as functional MRI (n = 200 data from public repositories, a series of experiments was performed to assess the impact of using a reduced parameter set (translationonly and rotationonly versus using the complete parameter set. It could be shown that the usage of 65 mm as an indicator of the average cortical distance is a valid approximation in adults, although care must be taken when comparing children and adults using the same measure. The effect of using slightly smaller or larger values is minimal. Further, both translationonly and rotationonly severely underestimate the full extent of subject motion; consequently, both translationonly and rotationonly discard substantially fewer datapoints when used for quality control purposes ("motion scrubbing". Finally, both translationonly and rotationonly severely underperform in predicting the full extent of the signal changes and the overall variance explained by motion in functional MRI data. These results suggest that a comprehensive measure, taking into account all available parameters, should be used to characterize subject motion in fMRI.
Wilke, Marko
2014-01-01
Subject motion has long since been known to be a major confound in functional MRI studies of the human brain. For resting-state functional MRI in particular, data corruption due to motion artefacts has been shown to be most relevant. However, despite 6 parameters (3 for translations and 3 for rotations) being required to fully describe the head's motion trajectory between timepoints, not all are routinely used to assess subject motion. Using structural (n = 964) as well as functional MRI (n = 200) data from public repositories, a series of experiments was performed to assess the impact of using a reduced parameter set (translationonly and rotationonly) versus using the complete parameter set. It could be shown that the usage of 65 mm as an indicator of the average cortical distance is a valid approximation in adults, although care must be taken when comparing children and adults using the same measure. The effect of using slightly smaller or larger values is minimal. Further, both translationonly and rotationonly severely underestimate the full extent of subject motion; consequently, both translationonly and rotationonly discard substantially fewer datapoints when used for quality control purposes ("motion scrubbing"). Finally, both translationonly and rotationonly severely underperform in predicting the full extent of the signal changes and the overall variance explained by motion in functional MRI data. These results suggest that a comprehensive measure, taking into account all available parameters, should be used to characterize subject motion in fMRI. PMID:25333359
First Gaia Local Group Dynamics: Magellanic Clouds Proper Motion and Rotation
van der Marel, Roeland P
2016-01-01
We use the Gaia data release 1 (DR1) to study the proper motion (PM) fields of the Large and Small Magellanic Clouds (LMC, SMC). This uses the Tycho-Gaia Astrometric Solution (TGAS) PMs for 29 Hipparcos stars in the LMC and 8 in the SMC. The LMC PM in the West and North directions is inferred to be $(\\mu_W,\\mu_N) = (1.874 \\pm 0.039, 0.223 \\pm 0.049)$ mas/yr, and the SMC PM $(\\mu_W,\\mu_N) = (0.876 \\pm 0.060, 1.227 \\pm 0.042)$ mas/yr. These results have similar accuracy and agree to within the uncertainties with existing Hubble Space Telescope (HST) PM measurements. Since TGAS uses different methods with different systematics, this provides an external validation of both data sets and their underlying approaches. Residual DR1 systematics may affect the TGAS results, but the HST agreement implies this must be below the random errors. Also in agreement with prior HST studies, the TGAS LMC PM field clearly shows the clockwise rotation of the disk, even though it takes the LMC disk in excess of $10^8$ years to comp...
Purpose: To quantitatively compare the accuracy of tumor volume segmentation in amplitude-based and phase-based respiratory gating algorithms in respiratory-correlated positron emission tomography (PET). Methods and Materials: List-mode fluorodeoxyglucose-PET data was acquired for 10 patients with a total of 12 fluorodeoxyglucose-avid tumors and 9 lymph nodes. Additionally, a phantom experiment was performed in which 4 plastic butyrate spheres with inner diameters ranging from 1 to 4 cm were imaged as they underwent 1-dimensional motion based on 2 measured patient breathing trajectories. PET list-mode data were gated into 8 bins using 2 amplitude-based (equal amplitude bins [A1] and equal counts per bin [A2]) and 2 temporal phase-based gating algorithms. Gated images were segmented using a commercially available gradient-based technique and a fixed 40% threshold of maximum uptake. Internal target volumes (ITVs) were generated by taking the union of all 8 contours per gated image. Segmented phantom ITVs were compared with their respective ground-truth ITVs, defined as the volume subtended by the tumor model positions covering 99% of breathing amplitude. Superior-inferior distances between sphere centroids in the end-inhale and end-exhale phases were also calculated. Results: Tumor ITVs from amplitude-based methods were significantly larger than those from temporal-based techniques (P=.002). For lymph nodes, A2 resulted in ITVs that were significantly larger than either of the temporal-based techniques (P<.0323). A1 produced the largest and most accurate ITVs for spheres with diameters of ≥2 cm (P=.002). No significant difference was shown between algorithms in the 1-cm sphere data set. For phantom spheres, amplitude-based methods recovered an average of 9.5% more motion displacement than temporal-based methods under regular breathing conditions and an average of 45.7% more in the presence of baseline drift (P<.001). Conclusions: Target volumes in images generated
Christie, Gregory J.; Cook, Charles M.; Ward, Brian J.; Tata, Matthew S.; Sutherland, Janice; Sutherland, Robert J.; Saucier, Deborah M.
2013-01-01
This study investigated how both sex and individual differences in a mental rotation test (MRT) influence performance on working memory (WM). To identify the neural substrate supporting these differences, brain electrical activity was measured using the event-related potential technique. No significant sex differences were observed in a test of verbal WM, however males were significantly faster than females to respond to probe stimuli in a test of spatial WM. This difference was no longer sig...
This work utilizes Improved Solar Observing Optical Network continuum (630.2 nm) and Hα (656.2 nm) data to: (1) detect and measure intrinsic sunspot rotations occurring in the photosphere and chromosphere, (2) identify and measure chromospheric filament mass motions, and (3) assess any large-scale photospheric and chromospheric mass couplings. Significant results from 2003 October 27-29, using the techniques of Brown et al., indicate significant counter-rotation between the two large sunspots in NOAA AR 10486 on October 29, as well as discrete filament mass motions in NOAA AR 10484 on October 27 that appear to be associated with at least one C-class solar flare
Harman Melinda K
2012-10-01
Full Text Available Abstract Background Clinical consequences of alignment errors in total knee replacement (TKR have led to the rigorous evaluation of surgical alignment techniques. Rotational alignment in the transverse plane has proven particularly problematic, with errors due to component malalignment relative to bone anatomic landmarks and an overall mismatch between the femoral and tibial components’ relative positions. Ranges of nominal rotational alignment are not well defined, especially for the tibial component and for relative rotational mismatch, and some studies advocate the use of mobile-bearing TKR to accommodate the resulting small rotation errors. However, the relationships between prosthesis rotational alignment and mobile-bearing polyethylene insert motion are poorly understood. This prospective, in vivo study evaluates whether component malalignment and mismatch affect axial rotation motions during passive knee flexion after TKR. Methods Eighty patients were implanted with mobile-bearing TKR. Rotational alignment of the femoral and tibial components was measured from postoperative CT scans. All TKR were categorized into nominal or outlier groups based on defined norms for surgical rotational alignment relative to bone anatomic landmarks and relative rotational mismatch between the femoral and tibial components. Axial rotation motion of the femoral, tibial and polyethylene bearing components was measured from fluoroscopic images acquired during passive knee flexion. Results Axial rotation motion was generally accomplished in two phases, dominated by polyethylene bearing rotation on the tibial component in early to mid-flexion and then femoral component rotation on the polyethylene articular surface in later flexion. Opposite rotations of the femur-bearing and bearing-baseplate articulations were evident at flexion greater than 80°. Knees with outlier alignment had lower magnitudes of axial rotation and distinct transitions from external to
Hardersen, Paul S.; Balasubramaniam, K. S.; Shkolyar, Svetlana
2013-01-01
This work utilizes Improved Solar Observing Optical Network (ISOON: Neidig et al. 2003) continuum (630.2 nm) and H{\\alpha} (656.2 nm) data to: 1) detect and measure intrinsic sunspot rotations occurring in the photosphere and chromosphere, 2) identify and measure chromospheric filament mass motions, and 3) assess any large-scale photospheric and chromospheric mass couplings. Significant results from October 27-29, 2003, using the techniques of Brown et al. (2003), indicate significant counter...
In this paper, the ratio of the mass coefficients for the γ-vibrational and rotational motion for the well deformed axially symmetric nuclei is calculated. Calculations are performed based on the cranking model approach. The results obtained show that the microscopic model based on the Woods–Saxon nuclear mean field potential and the pairing forces with a constant strength coefficient qualitatively explain the existing experimental data on the ratio of the mass coefficients. (author)
Phase motion in the $Z^-(4430)$ amplitude in $B^0\\to\\psi^\\prime\\pi^-K^+$ decay
Bediaga, Ignacio; de Miranda, Jussara M.(Centro Brasileiro de Pesquisas Físicas, Rua Xavier Sigaud 150, Rio de Janeiro, RJ, 22290-180, Brazil); Nielsen, Marina; Rodrigues, Fernando
2015-01-01
In view of the proliferation in the number of new charmonium states, it is really important to have a experimental way to prove that an observed bump is, indeed, a real resonance. To do that, in this paper we present an alternative method to demonstrate the resonant behavior of a state. With this method, the phase variation of a generic complex amplitude can be directly revealed through interference in the Dalitz-plot region where it crosses a well established resonant state, used as a probe....
Biomotors have been classified into linear and rotational motors. For 35 years, it has been popularly believed that viral dsDNA-packaging apparatuses are pentameric rotation motors. Recently, a third class of hexameric motor has been found in bacteriophage phi29 that utilizes a mechanism of revolution without rotation, friction, coiling, or torque. This review addresses how packaging motors control dsDNA one-way traffic; how four electropositive layers in the channel interact with the electronegative phosphate backbone to generate four steps in translocating one dsDNA helix; how motors resolve the mismatch between 10.5 bases and 12 connector subunits per cycle of revolution; and how ATP regulates sequential action of motor ATPase. Since motors with all number of subunits can utilize the revolution mechanism, this finding helps resolve puzzles and debates concerning the oligomeric nature of packaging motors in many phage systems. This revolution mechanism helps to solve the undesirable dsDNA supercoiling issue involved in rotation. - Highlights: • New motion mechanism of revolution without rotation found for phi29 DNA packaging. • Revolution motor finding expands classical linear and rotation biomotor classes. • Revolution motors transport dsDNA unidirectionally without supercoiling. • New mechanism solves many puzzles, mysteries, and debates in biomotor studies. • Motors with all numbers of subunits can utilize the revolution mechanism
Kalkan, Erol; Juan Carlos Reyes
2012-01-01
Building codes in the U.S. require at least two horizontal ground motion components for three-dimensional (3D) response history analysis (RHA) of structures. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHA analyses should be performed separately (when FN and then FP are aligned with transverse direction of the structural axes). It is assumed that this approach will lead to two sets of responses that envelope the range of possible responses over all non-redundant rotation angles. This assumption is examined here using 3D computer models of a single-story structure having symmetric (that is, torsionally-stiff) and asymmetric (that is, torsionally flexible) layouts subjected to an ensemble of bi-directional near-fault strong ground motions with and without apparent velocity pulses. In this parametric study, the elastic vibration period of the structures is varied from 0.2 to 5 seconds, and yield strength reduction factors R is varied from a value that leads to linear-elastic design to 3 and 5. The influence that the rotation angle of the ground motion has on several engineering demand parameters (EDPs) is examined in linear-elastic and nonlinear-inelastic domains to form a benchmark for evaluating the use of the FN/FP directions as well as the maximum-direction (MD) ground motion, a new definition of horizontal ground motions for use in the seismic design of structures according to the 2009 NEHRP Provisions and Commentary.
Yang, Jaehak; Kim, Junhoe; Kim, Bosung; Cho, Young-Jun; Lee, Jae-Hyeok; Kim, Sang-Koog
2016-07-01
We performed micromagnetic numerical calculations to explore a cylindrical nanotube's magnetization dynamics and domain-wall (DW) motions driven by eigen-circular-rotating magnetic fields of different frequencies. We discovered the presence of two different localized DW oscillations as well as asymmetric ferromagnetic resonance precession and azimuthal spin-wave modes at the corresponding resonant frequencies of the circular-rotating fields. Associated with these intrinsic modes, there exist very contrasting DW motions of different speed and propagation direction for a given DW chirality. The direction and speed of the DW propagation were found to be controllable according to the rotation sense and frequency of noncontact circular-rotating fields. Furthermore, spin-wave emissions from the moving DW were observed at a specific field frequency along with their Doppler effect. This work furthers the fundamental understanding of soft magnetic nanotubes' intrinsic dynamic modes and spin-wave emissions and offers an efficient means of manipulating the speed and direction of their DW propagations.
Tursunov, Arman; Kološ, Martin
2016-01-01
We study motion of charged particles in the field of a rotating black hole immersed into an external asymptotically uniform magnetic field, focusing on the epicyclic quasi-circular orbits near the equatorial plane. Separating the circular orbits into four qualitatively different classes according to the sign of the canonical angular momentum of the motion and the orientation of the Lorentz force, we analyse the circular orbits using the so called force formalism. We find the analytical solutions for the radial profiles of velocity, specific angular momentum and specific energy of the circular orbits in dependence on the black hole dimensionless spin and the magnetic field strength. The innermost stable circular orbits are determined for all four classes of the circular orbits. The stable circular orbits with outward oriented Lorentz force can extend to radii lower than the radius of the corresponding photon circular geodesic. We calculate the frequencies of the harmonic oscillatory motion of the charged parti...
Purpose: To develop and evaluate a correction strategy for prostate rotation using gantry and collimator angle adjustments. Methods and Materials: Gantry and collimator angle adjustments were used to correct for prostate rotation without rotating the table. A formula to partially correct for left-right (LR) rotations was derived through geometric analysis of rotation-induced clinical target volume (CTV) beam's-eye-view shape changes. For 10 prostate patients, intensity-modulated radiotherapy (IMRT) plans with different margins were created. Simulating CTV LR rotation and correcting each beam by a collimator rotation, the corrected CTV dose was compared with the original and uncorrected dose. Effects of residual geometric uncertainties were assessed using a Monte Carlo technique. A large number of treatments representative for prostate patients were simulated. Dose probability histograms of the minimum CTV dose (Dmin) were derived, with and without online correction, resulting in a more realistic margin estimate. Results: Dosimetric analysis of all IMRT plans showed that, with rotational correction and a 2-mm margin, Dmin was constant to within 3% for LR rotations up to ±15o. The Monte Carlo dose probability histograms showed that, with correction, a margin of 4 mm ensured that 90% of patients received a Dmin ≥95% of the prescribed dose. Without correction a margin of 6 mm was required. Conclusions: We developed and tested a practical method for (online) correction of prostate rotation, allowing safe and straightforward implementation of margin reduction and dose escalation
Simulation based analysis of the micro propulsion with rotating corkscrew motion of flagella
Koz, Mustafa
2009-01-01
In this work, a simulation based parametric analysis of a micro swimmer with a rotating helical tail is presented. The numeric model consists of micro swimmer positioned in a cylindrical micro channel. The flow induced by the rotating helical tail has a Reynolds number much smaller than 1 and it is solved by three dimensional, time dependent Navier Stokes equations subject to continuity. As a requirement of the changing orientation of the swimmer and its rotating helical tail in the micro cha...
The motion of an arbitrarily rotating spherical projectile and its application to ball games
In this paper the differential equations which govern the motion of a spherical projectile rotating about an arbitrary axis in the presence of an arbitrary ‘wind’ are developed. Three forces are assumed to act on the projectile: (i) gravity, (ii) a drag force proportional to the square of the projectile's velocity and in the opposite direction to this velocity and (iii) a lift or ‘Magnus’ force also assumed to be proportional to the square of the projectile's velocity and in a direction perpendicular to both this velocity and the angular velocity vector of the projectile. The problem has been coded in Matlab and some illustrative model trajectories are presented for ‘ball-games’, specifically golf and cricket, although the equations could equally well be applied to other ball-games such as tennis, soccer or baseball. Spin about an arbitrary axis allows for the treatment of situations where, for example, the spin has a component about the direction of travel. In the case of a cricket ball the subtle behaviour of so-called ‘drift’, particularly ‘late drift’, and also ‘dip’, which may be produced by a slow bowler's off or leg-spin, are investigated. It is found that the trajectories obtained are broadly in accord with those observed in practice. We envisage that this paper may be useful in two ways: (i) for its inherent scientific value as, to the best of our knowledge, the fundamental equations derived here have not appeared in the literature and (ii) in cultivating student interest in the numerical solution of differential equations, since so many of them actively participate in ball-games, and they will be able to compare their own practical experience with the overall trends indicated by the numerical results. As the paper presents equations which can be further extended, it may be of interest to research workers. However, since only the most basic principles of fundamental mechanics are employed, it should be well within the grasp of first
Soyka, Florian; Giordano, Paolo Robuffo; Barnett-Cowan, Michael; Bülthoff, Heinrich H
2012-07-01
Understanding the dynamics of vestibular perception is important, for example, for improving the realism of motion simulation and virtual reality environments or for diagnosing patients suffering from vestibular problems. Previous research has found a dependence of direction discrimination thresholds for rotational motions on the period length (inverse frequency) of a transient (single cycle) sinusoidal acceleration stimulus. However, self-motion is seldom purely sinusoidal, and up to now, no models have been proposed that take into account non-sinusoidal stimuli for rotational motions. In this work, the influence of both the period length and the specific time course of an inertial stimulus is investigated. Thresholds for three acceleration profile shapes (triangular, sinusoidal, and trapezoidal) were measured for three period lengths (0.3, 1.4, and 6.7 s) in ten participants. A two-alternative forced-choice discrimination task was used where participants had to judge if a yaw rotation around an earth-vertical axis was leftward or rightward. The peak velocity of the stimulus was varied, and the threshold was defined as the stimulus yielding 75 % correct answers. In accordance with previous research, thresholds decreased with shortening period length (from ~2 deg/s for 6.7 s to ~0.8 deg/s for 0.3 s). The peak velocity was the determining factor for discrimination: Different profiles with the same period length have similar velocity thresholds. These measurements were used to fit a novel model based on a description of the firing rate of semi-circular canal neurons. In accordance with previous research, the estimates of the model parameters suggest that velocity storage does not influence perceptual thresholds. PMID:22623095
The linear stability of a rotating Boussinesq fluid contained in a spherical shell to three-dimensional distrubances is studied in the presence of a general toroidal magnetic field. The local stability analysis used indicated that the stability of the system is not very different from that already known for the Malkus field (i.e. a field that varies directly as the distance from the rotation axis). The main influence of the general field is the introduction of a zonal flow which Doppler shifts the frequency of the waves. Consequently, the unstable waves in the geophysically relevant case of small q (=kappa/anti eta, where kappa, anti eta are, respectively, the thermal and magnetic diffusivities) drift eastward deep into the core and westward near the core-mantle boundary. For the astrophysically relevant situation q>>1 the presence of the zonal flow also blows the waves eastward in most of the core so that westward propagation is possible only in the top part of the core. (author)
Sayumi Iwamoto
2013-06-01
Full Text Available When a tennis player steps forward to hit a backhand groundstroke in closed stance, modifying the direction of the front foot relative to the net may reduce the risk of ankle injury and increase performance. This study evaluated the relationship between pelvic rotation and lower extremity movement during the backhand groundstroke when players stepped with toes parallel to the net (Level or with toes pointed towards the net (Net. High school competitive tennis players (eleven males and seven females, 16.8 ± 0.8 years, all right- handed performed tennis court tests comprising five maximum speed directional runs to the court intersection line to hit an imaginary ball with forehand or backhand swings. The final backhand groundstroke for each player at the backcourt baseline was analyzed. Pelvic rotation and lower extremity motion were quantified using 3D video analysis from frontal and sagittal plane camera views reconstructed to 3D using DLT methods. Plantar flexion of ankle and supination of the front foot were displayed for both Net and Level groups during the late phase of the front foot step. The timings of the peak pelvis rotational velocity and peak pelvis rotational acceleration showed different pattern for Net and Level groups. The peak timing of the pelvis rotational velocity of the Level group occurred during the late phase of the step, suggesting an increase in the risk of inversion ankle sprain and a decrease in stroke power compared to the Net group
Phase motion in the $Z^-(4430)$ amplitude in $B^0\\to\\psi^\\prime\\pi^-K^+$ decay
Bediaga, Ignacio; Nielsen, Marina; Rodrigues, Fernando
2015-01-01
In view of the proliferation in the number of new charmonium states, it is really important to have a experimental way to prove that an observed bump is, indeed, a real resonance. To do that, in this paper we present an alternative method to demonstrate the resonant behavior of a state. With this method, the phase variation of a generic complex amplitude can be directly revealed through interference in the Dalitz-plot region where it crosses a well established resonant state, used as a probe. We have tested the method for the $Z^-(4430)$ state by generating Monte Carlo samples for the $B^0\\to \\psi^\\prime \\pi^-K^+$ decay channel. We have shown that the proposed method gives a clear oscillation behavior, related to the phase variation associated to a real resonant state, in the case where the $Z^-(4430)$ is considered as a regular resonance with a strong phase variation. We have also discussed the possibility of using the proposed method complementary to the Argand diagram to determine the internal structure of...
Reverse rotations in the circularly-driven motion of a rigid body
Parisio, Fernando
2008-01-01
We study the dynamical response of a circularly-driven rigid body, focusing on the description of intrinsic rotational behavior (reverse rotations). The model system we address is integrable but nontrivial, allowing for qualitative and quantitative analysis. A scale free expression defining the separation between possible spinning regimes is obtained.
Nodehi-Moghadam, Afsun; Nasrin, Nasrin; Kharazmi, Aleeyehsadat; Eskandari, Zahra
2012-01-01
Purpose The repetitive micro traumatic stresses placed on the athletes shoulder joint complex during the throwing motion challenge the surrounding tissues. The purpose of this study was to compare shoulder rotational strength, range of motion and proprioception between the throwing athletes and non-athletic persons. Methods Fifteen throwing athletes and 15 non-athletes participated in a nonrandom case – control study. Strength of shoulder rotational movements was tested with a hand held dynam...
Mancini, L.; Giacobbe, P.; Littlefair, S. P.; Southworth, J.; Bozza, V.; Damasso, M.; Dominik, M.; Hundertmark, M.; Jørgensen, U. G.; Juncher, D.; Popovas, A.; Rabus, M.; Rahvar, S.; Schmidt, R. W.; Skottfelt, J.; Snodgrass, C.; Sozzetti, A.; Alsubai, K.; Bramich, D. M.; Calchi Novati, S.; Ciceri, S.; D'Ago, G.; Figuera Jaimes, R.; Galianni, P.; Gu, S.-H.; Harpsøe, K.; Haugbølle, T.; Henning, Th.; Hinse, T. C.; Kains, N.; Korhonen, H.; Scarpetta, G.; Starkey, D.; Surdej, J.; Wang, X.-B.; Wertz, O.
2015-12-01
Context. Photometric monitoring of the variability of brown dwarfs can provide useful information about the structure of clouds in their cold atmospheres.The brown-dwarf binary system Luhman 16AB is an interesting target for such a study, because its components stand at the L/T transition and show high levels of variability. Luhman 16AB is also the third closest system to the solar system, which allows precise astrometric investigations with ground-based facilities. Aims: The aim of the work is to estimate the rotation period and study the astrometric motion of both components. Methods: We have monitored Luhman 16AB over a period of two years with the lucky-imaging camera mounted on the Danish 1.54 m telescope at La Silla, through a special i + z long-pass filter, which allowed us to clearly resolve the two brown dwarfs into single objects. An intense monitoring of the target was also performed over 16 nights, in which we observed a peak-to-peak variability of 0.20 ± 0.02 mag and 0.34 ± 0.02 mag for Luhman 16A and 16B, respectively. Results: We used the 16-night time-series data to estimate the rotation period of the two components. We found that Luhman 16B rotates with a period of 5.1 ± 0.1 h, in very good agreement with previous measurements. For Luhman 16A, we report that it rotates more slowly than its companion, and even though we were not able to get a robust determination, our data indicate a rotation period of roughly 8 h. This implies that the rotation axes of the two components are well aligned and suggests a scenario in which the two objects underwent the same accretion process. The 2-year complete data set was used to study the astrometric motion of Luhman 16AB. We predict a motion of the system that is not consistent with a previous estimate based on two months of monitoring, but cannot confirm or refute the presence of additional planetary-mass bodies in the system. Based on data collected by MiNDSTEp with the Danish 1.54 m telescope at the ESO La
Elisa Benedetti
2016-01-01
Full Text Available We address the problem of low amplitude oscillatory motion detection through different low-cost sensors: a LIS3LV02DQ MEMS accelerometer, a Microsoft Kinect v2 range camera, and a uBlox 6 GPS receiver. Several tests were performed using a one-direction vibrating table with different oscillation frequencies (in the range 1.5–3 Hz and small challenging amplitudes (0.02 m and 0.03 m. A Mikrotron EoSens high-resolution camera was used to give reference data. A dedicated software tool was developed to retrieve Kinect v2 results. The capabilities of the VADASE algorithm were employed to process uBlox 6 GPS receiver observations. In the investigated time interval (in the order of tens of seconds the results obtained indicate that displacements were detected with the resolution of fractions of millimeters with MEMS accelerometer and Kinect v2 and few millimeters with uBlox 6. MEMS accelerometer displays the lowest noise but a significant bias, whereas Kinect v2 and uBlox 6 appear more stable. The results suggest the possibility of sensor integration both for indoor (MEMS accelerometer + Kinect v2 and for outdoor (MEMS accelerometer + uBlox 6 applications and seem promising for structural monitoring applications.
Rotational motion of dusty structures in glow discharge in longitudinal magnetic field
The investigation of dust structure formed in glow discharge in an external longitudinal magnetic field with induction up to 400 G applied is presented in this work. The dust structure starts to rotate in the magnetic field. The angular-velocity magnitude is one to two orders larger than one in other discharge types. Its dependence on the magnetic field is nonmonotonic. The rotation direction inverses with an increase of the magnetic induction value up to a certain magnitude B0. In close range of induction around B0 and under certain conditions the rotation of the upper and lower parts of the structure in the opposite direction is observed. Rotation is caused by the ion-drag force. The inversion of rotation direction relates with the change of plasma flows in the area of their formation in stratum with the magnetic field applied. The effect of ion flows was investigated in two additional experiments on the observation of structure rotation onset and on gravity-driven probing of stratum. The angular-velocity unhomogeniety allowed us to investigate shearing and to observe melting of the dust crystal. The correlation functions approach showed the occurrence of structure transformation and its phase transition of the meltinglike type in the magnetic field
The so-called “particles-on-a-sphere” (POS) model has been introduced a while ago in order to describe in simple terms large-amplitude motion of polyatomic hydrides, XHn. The POS model of protonated methane, CH5+, has been shown to capture well the essence of the fluxional nature of this enigmatic floppy molecule. Here, we extend this model to the POSflex force field by adding flexibility to the C–H bonds, which are constrained to a common fixed bond length in the original model. This makes the present model extremely efficient for computer simulation, including path integral molecular dynamics in order to assess the crucial quantum effects on nuclear motion at low temperatures. Moreover, the POSflex force field can be conveniently used to study microsolvation effects upon combining it with intermolecular pair potentials to account for solute-solvent interactions. Upon computing static properties as well as thermal and quantum fluctuation effects at ambient and low temperatures, respectively, it is shown that the POSflex model is very well suited to describe the structural properties of bare CH5+, including hydrogen scrambling and thus fluxionality in the first place. The far- to mid-infrared spectrum up to the bending band is roughly described, whereas the model fails to account for the well-structured stretching band by construction
Uhl, Felix; Walewski, Łukasz; Forbert, Harald; Marx, Dominik [Lehrstuhl für Theoretische Chemie, Ruhr-Universität Bochum, 44780 Bochum (Germany)
2014-09-14
The so-called “particles-on-a-sphere” (POS) model has been introduced a while ago in order to describe in simple terms large-amplitude motion of polyatomic hydrides, XH{sub n}. The POS model of protonated methane, CH{sub 5}{sup +}, has been shown to capture well the essence of the fluxional nature of this enigmatic floppy molecule. Here, we extend this model to the POSflex force field by adding flexibility to the C–H bonds, which are constrained to a common fixed bond length in the original model. This makes the present model extremely efficient for computer simulation, including path integral molecular dynamics in order to assess the crucial quantum effects on nuclear motion at low temperatures. Moreover, the POSflex force field can be conveniently used to study microsolvation effects upon combining it with intermolecular pair potentials to account for solute-solvent interactions. Upon computing static properties as well as thermal and quantum fluctuation effects at ambient and low temperatures, respectively, it is shown that the POSflex model is very well suited to describe the structural properties of bare CH{sub 5}{sup +}, including hydrogen scrambling and thus fluxionality in the first place. The far- to mid-infrared spectrum up to the bending band is roughly described, whereas the model fails to account for the well-structured stretching band by construction.
Awali, Slim; Poisson, Lionel; Rhouma, Mounir Ben El Hadj; Mestdagh, Jean-Michel
2015-09-17
Photoabsorption spectra of KArn (n = 1-10) are simulated at temperatures ranging between 5 and 25 K. The calculations associate a Monte Carlo (MC) method to sample cluster geometries at temperature T, with a one-electron ab initio model to calculate the ground-state and excited-state energies of the cluster. The latter model replaces the K(+) core electrons and all the electrons of the Ar atoms by appropriate pseudopotentials, complemented by core polarization potentials. It also provides the necessary oscillator strengths to simulate the spectra. Global optimization by basin-hopping is used in combination with MC simulation at low temperature (5 K) to identify the most stable isomer and remarkable isomers of ground-state KArn clusters, which are stable with respect to deformations of the order of those expected with Zero Point Energy motions. The absorption spectra calculated for each of these isomers at 5 K suggest that absorption spectroscopy can probe sensitively the local environment of K atom: surface location of K with respect to a close-packed Ar moiety, number of Ar atom in close vicinity, and local symmetry about K. Simulation at increasing temperatures, up to the evaporation limit of K out of the cluster, shows the onset of large amplitude motions above 20 K, when the K atom experiences a variety of local environments. PMID:26301681
Haddout, Soufiane
2016-06-01
In Newtonian mechanics, the non-inertial reference frames is a generalization of Newton's laws to any reference frames. While this approach simplifies some problems, there is often little physical insight into the motion, in particular into the effects of the Coriolis force. The fictitious Coriolis force can be used by anyone in that frame of reference to explain why objects follow curved paths. In this paper, a mathematical solution based on differential equations in non-inertial reference is used to study different types of motion in rotating system. In addition, the experimental data measured on a turntable device, using a video camera in a mechanics laboratory was conducted to compare with mathematical solution in case of parabolically curved, solving non-linear least-squares problems, based on Levenberg-Marquardt's and Gauss-Newton algorithms.
Chirikjian, Gregory S.; Wang, Yunfeng
2000-07-01
Partial differential equations (PDE's) for the probability density function (PDF) of the position and orientation of the distal end of a stiff macromolecule relative to its proximal end are derived and solved. The Kratky-Porod wormlike chain, the Yamakawa helical wormlike chain, and the original and revised Marko-Siggia models are examples of stiffness models to which the present formulation is applied. The solution technique uses harmonic analysis on the rotation and motion groups to convert PDE's governing the PDF's of interest into linear algebraic equations which have mathematically elegant solutions.
Roy Jean-Sébastien
2009-03-01
Full Text Available Abstract Background Different measurements are used to assess shoulder function, including range of motion, strength, functional performance and self-report function. To understand disablement, it is necessary to understand the relationship between impairments and function in persons without shoulder problems. This study was conducted to enhance existing comparative data in subjects without upper extremity pathology, and to assess the relationships between impairments (range of motion, strength and self-reported or measured function/disability. The impact of age, gender and dominance was determined. Methods Two-hundred ninety-four subjects with unaffected shoulders were recruited. The subjects (mean age: 37 years old were divided into three subgroups, 18–39, 40–59, and over 60 years of age. During a single session, at least two of the following variables were measured: self-reported function (shoulder disability scales, range of motion, isometric rotational strength, or upper limb functional performance (FIT-HaNSA. Two-way analysis of variance was used to determine, for each variable, the effects of age and gender. The relationship between the outcomes was established using Pearson product correlations. Results Men were significantly stronger than women for all age categories. There was an age-related decline in strength in men in the over-60 age category. Significant negative correlations between strength and range of motion were demonstrated (-0.22 r r = -0.202. Conclusion Self-reported disability was low in individuals without upper extremity problems, although recruitment of such individuals was difficult in the older age groups due to the high prevalence of shoulder pathology. A low correlation between self-report disability and strength/range of motion in these unaffected subjects reflects the lack of disability reported by all subjects without pathology despite normal variations in strength and motion.
Light-driven three-dimensional rotational motion of dandelion-shaped microparticles
Shpaisman, Hagay; Ruffner, David B.; Grier, David G.
2013-02-01
Chemically synthesized colloidal particles featuring large-scale surface asperities can be trapped and manipulated in fluid media through holographic optical trapping. Light scattering by these particles' surface features provides a mechanism for holographic optical traps also to exert torques on them, thereby setting them in steady rotation about arbitrary axes in three dimensions. When pairs of rotating particles are brought close enough that their surface features mesh, they form microscopic gear trains. These micro-opto-mechanical systems can be arranged in any desired three-dimensional configuration.
Effect of octupole interaction on the rotational motion of rotors in a solid Kr-CD4 solution
The heat capacity of solid (CD4)nKr1-n solutions with CD4 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 O2 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 CD4 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 O2 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
Fernanda Chiarion Sassi
2011-04-01
Full Text Available Regarding orofacial motor assessment in facial paralysis, quantitative measurements of the face are being used to establish diagnosis, prognosis and treatment planning. AIM: To assess the prevalence of changes in mandibular range of motion in individuals with peripheral facial paralysis. MATERIALS AND METHODS: Prospective study. We had 56 volunteers, divided in two groups: G1 made up of 28 individuals with idiopathic facial paralysis (6 males and 22 females; 14 with manifestations on the right side of the face and 14 on the left side; time of onset varied between 6-12 months; G2 with 28 healthy individuals paired by age and gender to G1. In order to assess mandibular range of motion, a digital caliper was used. The following measurements were made: 1 middle line; 2 maximum oral opening; 3 lateralization to the right; 4 lateralization to the left; 5 protrusion; 6 horizontal overlap. RESULTS: Statistically significant differences between the groups were observed for maximum oral opening, lateralization to the left and protrusion. G1 presented smaller measurement values than G2. CONCLUSION: Patients with facial paralysis present significant reduction of mandibular range of motion. The results support the suggestion of incorporating functional evaluation of the temporomandibular joint to the existing facial paralysis clinical assessment protocols.Na atuação fonoaudiológica na paralisia facial, medidas quantitativas da face têm sido cada vez mais utilizadas para avaliação, diagnóstico, prognóstico e planejamento terapêutico. OBJETIVO: Avaliar a prevalência de alterações de amplitude mandibular na paralisia facial periférica de origem. MATERIAL E MÉTODO: Estudo prospectivo. Cinquenta e seis indivíduos foram divididos em dois grupos: G1 com 28 pacientes com paralisia facial idiopática (6 homens e 22 mulheres, 14 com comprometimento à direita e 14 à esquerda e tempo de duração da paralisia entre 6 e 12 meses; G2 composto por 28 indiv
Reconstructing rotations and rigid body motions from exact point correspondences through reflections
D. Fontijne; L. Dorst
2011-01-01
We describe a new algorithm to reconstruct a rigid body motion from point correspondences. The algorithm works by constructing a series of reflections which align the points with their correspondences one by one. This is naturally and efficiently implemented in the conformal model of geometric algeb
Barrado, D; Bouvier, J; Moraux, E; Sarro, L M; Bertin, E; Cuillandre, J C; Stauffer, J R; Lillo-Box, J; Pollock, A
2016-01-01
Stellar clusters are open windows to understand stellar evolution. Specifically, the change with time and the dependence on mass of different stellar properties. As such, they are our laboratories where different theories can be tested. We try to understand the origin of the connection between lithium depletion in F, G and K stars, rotation and activity, in particular in the Pleiades open cluster. We have collected all the relevant data in the literature, including information regarding rotation period, binarity and activity, and cross-matched with proper motions, multi-wavelength photometry and membership probability from the DANCe database. In order to avoid biases, only Pleiades single members with probabilities larger than p=0.75 have been included in the discussion. Results. The analysis confirms that there is a strong link between activity, rotation and the lithium equivalent width excess, specially for the range Lum(bol) = 0.5-0.2 Lsun (about K2-K7 spectral types or 0.75-0.95 Msun). It is not possible ...
The phenomenological symplectic model with a Davidson potential is used to construct rotational states for a rare-earth nucleus with microscopic wave functions. The energy levels and E2 transitions obtained are in remarkably close agreement (to within a few percent) with those of the rotor model with vibrational shape fluctations that are adiabatically decoupled from the rotational degrees of freedom. An analysis of the states in terms of their SU(3) content shows that SU(3) is a very poor dynamical symmetry but an excellent quasi-dynamical symmetry for the model. It is argued that such quasi-dynamical symmetry can be expected for any Hamiltonian that reproduces the observed low-energy properties of a well-deformed nucleus, whenever the latter are well-described by the nuclear rotor model
Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story
Weinstein, Galina
2014-01-01
On November 18, 1915 Einstein reported to the Prussian Academy that the perihelion motion of Mercury is explained by his new General Theory of Relativity: Einstein found approximate solutions to his November 11, 1915 field equations. Einstein's field equations cannot be solved in the general case, but can be solved in particular situations. The first to offer such an exact solution was Karl Schwarzschild. Schwarzschild found one line element, which satisfied the conditions imposed by Einstein...
Baranyai, Tamás; Várkonyi, Péter L
2016-01-01
This paper presents a partial reconstruction of the rotational dynamics of the Philae spacecraft upon landing on comet 67P/Churyumov-Gerasimenko as part of ESA's Rosetta mission. We analyze the motion and the events triggered by the failure to fix the spacecraft to the comet surface at the time of the first touchdown. Dynamic trajectories obtained by numerical simulation of a 7 degree-of-freedom mechanical model of the spacecraft are fitted to directions of incoming solar radiation inferred from in-situ measurements of the electric power provided by the solar panels. The results include a lower bound of the angular velocity of the lander immediately after its first touchdown. Our study also gives insight into the effect of the programmed turn-off of the stabilizing gyroscope after touchdown; the important dynamical consequences of a small collision during Philae's journey; and the probability that a similar landing scenario harms the operability of this type of spacecraft.
A rotational and axial motion system load frame insert for in situ high energy x-ray studies
High energy x-ray characterization methods hold great potential for gaining insight into the behavior of materials and providing comparison datasets for the validation and development of mesoscale modeling tools. A suite of techniques have been developed by the x-ray community for characterizing the 3D structure and micromechanical state of polycrystalline materials; however, combining these techniques with in situ mechanical testing under well characterized and controlled boundary conditions has been challenging due to experimental design requirements, which demand new high-precision hardware as well as access to high-energy x-ray beamlines. We describe the design and performance of a load frame insert with a rotational and axial motion system that has been developed to meet these requirements. An example dataset from a deforming titanium alloy demonstrates the new capability
Hui, Tsz Hin; Zheng, Fan; Lin, Yuan; Fu, Chuanhai
2016-05-01
Dynamic nuclei are involved in a wide variety of fundamental biological processes including cell migration, cell division and fertilization. Here, we develop a mathematical model, in combination with live-cell imaging at high temporal resolution, to quantitatively elucidate how the linear and rotational motions of the nucleus are governed by the stochastic dynamics of the microtubule cytoskeleton. Our simulation and experimental results demonstrate that microtubule rescue and catastrophe frequencies are the decisive factors in regulating the nuclear movement. Lower rescue and catastrophe frequencies can lead to significantly larger angular and translational oscillations of the nucleus. In addition, our model also suggests that the stochastic dynamics of individual spatially distributed microtubules works collectively as a restoring force to maintain nuclear centering and hence ensures symmetric cell division, in excellent agreement with direct experimental observations. PMID:26921917
Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion
Nevares, Giselle; Xavier, Felipe; Gominho, Luciana; Cavalcanti, Flávia; Cassimiro, Marcely; Romeiro, Kaline; Alvares, Pamella; Queiroz, Gabriela; Sobral, Ana Paula; Gerbi, Marleny; Silveira, Marcia; Albuquerque, Diana
2015-01-01
This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n = 20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer's instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α = 5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p < 0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p < 0.001). Cross section and motion influenced the results, despite tip standardization. PMID:26543896
Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion.
Nevares, Giselle; Xavier, Felipe; Gominho, Luciana; Cavalcanti, Flávia; Cassimiro, Marcely; Romeiro, Kaline; Alvares, Pamella; Queiroz, Gabriela; Sobral, Ana Paula; Gerbi, Marleny; Silveira, Marcia; Albuquerque, Diana
2015-01-01
This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n = 20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer's instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α = 5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p < 0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p < 0.001). Cross section and motion influenced the results, despite tip standardization. PMID:26543896
Wei, J.-H. [Shanghai Univ. (China). Shanghai Enhanced Laboratory of Ferrous Metallurgy, Department of Metallic Materials
2003-02-01
Water modelling was used to investigate the fluid flow and mixing characteristics in the bath of an 18 t AOD vessel with non-rotating and rotating gas jets, blown respectively through two annular straight-tube and spiral-flat tuyeres at a sufficiently full kinematic similarity. A spiral flat brass sheet was installed in the central tube (the main tuyere) of the tuyere used to obtain a rotating gas jet. The geometric similarity ratio between the model and its prototype (including the straight-tube type tuyeres) was 1:3. The influences of the rotating motion of the gas jets on the characteristics at different gas flow rates, angles included between the two tuyeres and other operating parameters, and the suitability of the spiral tuyere as a practical application, were examined. The results showed that the rotating motion of gas jets could considerably influence and change the features of gas stirring and liquid flow in the bath. Compared to the non-rotating gas jet, the rotating jet provides a stronger agitation and causes a more vigorous swirling and circulatory motion of the fluids, at the same gas flow rate. This leads to a better mixing efficiency than the non-rotating jet. The gas flow rate of the spiral main tuyere has the larger influence on the fluid flow and mixing in the bath than that of the straight main tuyere. The non-rotating gas jet of the subtuyere also has a physical shielding effect on the rotating gas jet of the main tuyere, but the action is obviously weakened owing to the rotating motion of the main tuyere jet. The included angle between the two annular spiral-flat tuyeres has a stronger effect on the fluid flow and the stability of the blowing process, and its optimal range is narrower than when utilising the annular straight-tube tuyeres. The optimum angle between the two tuyeres for rotating jets is 80 under the experimental conditions. Use of a gas jet with a suitable rotating intensity is feasible, and an annular-spiral tube tuyere with a
Jiang, Xing; O'Brien, Zachary J; Yang, Song; Lai, Lan Huong; Buenaflor, Jeffrey; Tan, Colleen; Khan, Saeed; Houk, K N; Garcia-Garibay, Miguel A
2016-04-01
Low packing densities are key structural features of amphidynamic crystals built with static and mobile components. Here we report a loosely packed crystal of dendrimeric rotor 2 and the fast dynamics of all its aromatic groups, both resulting from the hyperbranched structure of the molecule. Compound 2 was synthesized with a convergent strategy to construct a central phenylene core with stators consisting of two layers of triarylmethyl groups. Single crystal X-ray diffraction analysis confirmed a low-density packing structure consisting of one molecule of 2 and approximately eight solvent molecules per unit cell. Three isotopologues of 2 were synthesized to study the motion of each segment of the molecule in the solid state using variable temperature quadrupolar echo (2)H NMR spectroscopy. Line shape analysis of the spectra reveals that the central phenylene, the six branch phenylenes, and the 18 periphery phenyls all display megahertz rotational dynamics in the crystals at ambient temperature. Arrhenius analysis of the data gives similar activation energies and pre-exponential factors for different parts of the structure. The observed pre-exponential factors are 4-6 orders of magnitude greater than those of elementary site-exchange processes, indicating that the dynamics are not dictated by static energetic potentials. Instead, the activation energies for rotations in the crystals of 2 are controlled by temperature dependent local structural fluctuations and crystal fluidity. PMID:26973017
Seminati, Elena; Marzari, Alessandra; Vacondio, Oreste; Minetti, Alberto E
2015-06-01
Repetitive stresses and movements on the shoulder in the volleyball spike expose this joint to overuse injuries, bringing athletes to a career threatening injury. Assuming that specific spike techniques play an important role in injury risk, we compared the kinematic of the traditional (TT) and the alternative (AT) techniques in 21 elite athletes, evaluating their safety with respect to performance. Glenohumeral joint was set as the centre of an imaginary sphere, intersected by the distal end of the humerus at different angles. Shoulder range of motion and angular velocities were calculated and compared to the joint limits. Ball speed and jump height were also assessed. Results indicated the trajectory of the humerus to be different for the TT, with maximal flexion of the shoulder reduced by 10 degrees, and horizontal abduction 15 degrees higher. No difference was found for external rotation angles, while axial rotation velocities were significantly higher in AT, with a 5% higher ball speed. Results suggest AT as a potential preventive solution to shoulder chronic pathologies, reducing shoulder flexion during spiking. The proposed method allows visualisation of risks associated with different overhead manoeuvres, by depicting humerus angles and velocities with respect to joint limits in the same 3D space. PMID:26151344
Statistical investigation of factors affecting rotational motion in even-even nuclei
The distribution of rotational energy spacings for low-spin yrast states in over two thousand pairs of deformed rare-earth even-even nuclei are studied to determine key factors that correlate with the moments of inertia. Nuclei with near identical P values (P=NpNn/[Np+Nn] where Np and Nn are the numbers of valence protons and valence neutrons) are more than an order of magnitude more likely to show near identical bands than nuclei with different P values. This is, by far, the highest correlation found: no other variable is even 20% as effective. The statistical significance of these large P enhancements and the special relation between P and ground-state mean-field structures is confirmed by a complementary analysis of negative parity near identical bands, which show no P enhancement at all
At Penn State the Nuclear Engineering students have the opportunity to perform experiments in reactor physics, work with reactor and radiation instrumentation, and operate a nuclear reactor. These activities are done at the Penn State Breazeale Reactor (PSBR), a General Atomics Mark III TRIGA reactor. Unfortunately this activity alone can not fully support the facility. The PSBR is mandated by Penn State to provide a portion of its operating budget by selling services to users outside as well as inside Penn State. In order to increase the marketability of PSBR an upgrade program was started to increase the quality and versatility of operation. The PSBR is the longest operating university reactor in the United States. The first phase of the upgrade program began in 1992. The quality of operation was increased by replacing a 1965 vintage console with a more reliable digital control and monitoring system. The present phase of the upgrade program is to increase the versatility of operation by modifying the reactor to allow transverse and rotational core motion. Adding two more degrees of motion to the reactor core increases the capability of the facility to meet the needs of present and future users. This upgrade is being financed by a grant from the Department of Energy and matching funds from Penn State. (author)
Einstein, Schwarzschild, the Perihelion Motion of Mercury and the Rotating Disk Story
Weinstein, Galina
2014-01-01
On November 18, 1915 Einstein reported to the Prussian Academy that the perihelion motion of Mercury is explained by his new General Theory of Relativity: Einstein found approximate solutions to his November 11, 1915 field equations. Einstein's field equations cannot be solved in the general case, but can be solved in particular situations. The first to offer such an exact solution was Karl Schwarzschild. Schwarzschild found one line element, which satisfied the conditions imposed by Einstein on the gravitational field of the sun, as well as Einstein's field equations from the November 18, 1915 paper. On December 22, 1915 Schwarzschild told Einstein that he reworked the calculation in his November 18 1915 paper of the Mercury perihelion. Subsequently Schwarzschild sent Einstein a manuscript, in which he derived his exact solution of Einstein's field equations. On January 13, 1916, Einstein delivered Schwarzschild's paper before the Prussian Academy, and a month later the paper was published. In March 1916 Ein...
José L. Costa Sepúlveda
2011-12-01
Full Text Available The purpose of the study was to assess flexibility and range of motion in flamenco dancers of Cádiz, Sevilla and Jaén (Spain through a tests battery. The study population comprised 37 healthy flamenco dancers (25 ± 7,2 years, 1,6 ± 0,5 m y 56 ± 7,6 Kg. They performed a range of flexibility and motion tests (i.e. Kendall test, Nachlas test. Results has shown that there is muscle shortening in most of the tests that flamenco dancers has passed. We conclude that there are not many articles on physiological and fitness aspects of dance and we think that it is necessary a specific physical dancer training, to prevent injuries and to extend dancers life.El objetivo de este estudio es la valoración de la flexibilidad muscular y la amplitud articular en bailaoras de flamenco de la provincia de Cádiz, Sevilla y Jaén, a través de una batería de tests. En el estudio participaron 37 bailaoras de danza flamenca de 25 ± 7,2 años, con una altura con valores de 1,6 ± 0,5 m y 56 ± 7,6 Kg de peso. La batería está compuesta de las siguientes pruebas que se realizarán a través del protocolo de actuación especificado: Prueba de rotadores internos y aductores del hombro, Prueba de Kendall, Prueba de Diagonal Posterior, Prueba de Nachlas, Prueba de Ridge, Prueba de Flexión de cadera con rodilla en extensión, Prueba de Thomas y Prueba de Elongación de los flexores plantares. Los resultados demuestran que existen acortamientos en diferente musculatura implicada como los rotadores internos y aductores del hombro, dorsal ancho, pectoral mayor, redondo mayor, cintura escapular, psoas-ilíaco, recto anterior del muslo y sóleo. Concluir con la escasa existencia de artículos relacionados con la valoración de la condición física de bailarines de cualquier modalidad de danza y con la necesaria aplicación de un entrenamiento planificado complementario con una propuesta de ejercicios de mejora de la musculatura implicada y, así, poder prevenir futuras
Sato, Koji; Maeda, Akira; Takano, Yoshio; Matsuse, Hiroo; Ida, Hirofumi; Shiba, Naoto
2013-01-01
The anterior cruciate ligament (ACL) plays an important role in controlling knee joint stability, not only by limiting tibial anterior translation but also by controlling knee axial rotation. The aim of ACL reconstruction is to reduce excessive anterior joint laxity, hoping to restore normal tibiofemoral kinematics including knee axial rotation. The purpose of this study was to investigate the relationship between static anterior instability and tibial rotation during several activities in an anterior cruciate ligament reconstructed knee. Seven patients with unilateral ACL injury performed plain walking, running, landing and side step cutting tasks after ACL reconstruction with a mean follow-up of 14 months. The kinematic data for the 4 motions was measured using a motion analysis system and the point cluster technique. The evaluation period was defined to be from the first contact to removal of the tested leg from the ground. Maximum tibial internal rotation during tasks was calculated using the point cluster technique (PCT). Passive anterior tibial translation was measured using a KT-1000 arthrometer. Regression analysis was used to determine the correlation of the maximum internal rotation with the side-to-side difference of static anterior tibial translation measured using a KT-1000 arthrometer. During side step cutting maneuvers, maximum tibial internal rotation significantly showed negative correlation with static anterior tibial translation (pknee rotation kinematics. The normal anterior tibial translation obtained by ACL reconstruction is thought to be the key factor in successful restoration of normal knee kinematics. PMID:23925154
Rozovski, David; Theodore, Colin R.
2011-01-01
An experiment was conducted to compare a conventional helicopter Thrust Control Lever (TCL) to the Rotational Throttle Interface (RTI) for tiltrotor aircraft. The RTI is designed to adjust its orientation to match the angle of the tiltrotor s nacelles. The underlying principle behind the design is to increase pilot awareness of the vehicle s configuration state (i.e. nacelle angle). Four test pilots flew multiple runs on seven different experimental courses. Three predominant effects were discovered in the testing of the RTI: 1. Unintentional binding along the control axis resulted in difficulties with precision power setting, 2. Confusion in which way to move the throttle grip was present during RTI transition modes, and 3. Pilots were not able to distinguish small angle differences during RTI transition. In this experiment the pilots were able to successfully perform all of the required tasks with both inceptors although the handling qualities ratings were slightly worse for the RTI partly due to unforeseen deficiencies in the design. Pilots did however report improved understanding of nacelle movement during transitions with the RTI.
Incoherent quasielastic neutron scattering experiments were performed on a series of urea inclusion compounds n-CnH2n+2/urea with n=9.15. Using semi oriented samples, we were able to record the spectra in two geometries, i.e. with the Q momentum transfer vector parallel (Qparallel) and perpendicular (Qperpendicular) to the urea host tunnel axis. Reorientational and translational motions could therefore be investigated separately in both the low temperature (LT) and high temperature (HT) phases of the samples. The low frequency excitations observed in the LT phase and only in the Qparallel geometry could be assigned to the sliding mode of one sublattice (the n alkane guests) with respect to the other (the urea host). We have quantitatively analyzed the spectra by means of a model of damped oscillator and interpreted the results on the basis of the structural properties of these composite incommensurate systems. On the characteristic timescale of the experiments, reorientations of the n alkane chains are effective only in the HT phases of the compounds. (authors). 15 refs., 4 figs., 3 tabs
Lekner, John
2008-01-01
Any free-particle wavepacket solution of Schrodinger's equation can be converted by differentiations to wavepackets rotating about the original direction of motion. The angular momentum component along the motion associated with this rotation is an integral multiple of [h-bar]. It is an "intrinsic" angular momentum: independent of origin and…
Monitoring Vibration of A Model of Rotating Machine
Arko Djajadi; Arsi Azavi; Rusman Rusyadi; Erikson Sinaga
2012-01-01
Mechanical movement or motion of a rotating machine normally causes additional vibration. A vibration sensing device must be added to constantly monitor vibration level of the system having a rotating machine, since the vibration frequency and amplitude cannot be measured quantitatively by only sight or touch. If the vibration signals from the machine have a lot of noise, there are possibilities that the rotating machine has defects that can lead to failure. In this experimental research proj...
Visual-Motion Cueing in Altitude and Yaw Control
Johnson, Walter W.; Schroeder, Jeffery; Statler, Irving C. (Technical Monitor)
1994-01-01
Research conducted using the Vertical Motion Simulator at the NASA Ames Research Center examined the contributions of platform motion and visual level-of-detail (LOD) cueing to tasks that required altitude and/or yaw control in a simulated AH-64 Apache helicopter. Within the altitude control tasks the LOD manipulation caused optical density to change across altitudes by a small, moderate, or large amount; while platform motion was either present or absent. The results from these tasks showed that both constant optical density and platform motion improved altitude awareness in an altitude repositioning task, while the presence of platform motion also led to improved performance in a vertical rate control task. The yaw control tasks had pilots'sit 4.5 ft in front of the center of rotation, thus subjecting them to both rotational and lateral motions during a yaw. The pilots were required to regulate their yaw, while the platform motion was manipulated in order to present all combinations of the resulting rotational and lateral motion components. Ratings of simulation fidelity and sensed platform motion showed that the pilots were relatively insensitive to the rotational component, but highly aware of the lateral component. Together these findings show that: 1) platform motion cues are important when speed regulation is required during altitude change; 2) platform motion contributes to the perception of movement amplitude; 3) lateral, but not rotational, motion cues are essential to the perception of vehicle yaw; and 4) LOD management yielding constant optical density across altitudes improves altitude awareness.
Pavlov, Dmitry A.; Williams, James G.; Suvorkin, Vladimir V.
2016-07-01
The aim of this work is to combine the model of orbital and rotational motion of the Moon developed for DE430 with up-to-date astronomical, geodynamical, and geo- and selenophysical models. The parameters of the orbit and physical libration are determined in this work from lunar laser ranging (LLR) observations made at different observatories in 1970-2013. Parameters of other models are taken from solutions that were obtained independently from LLR. A new implementation of the DE430 lunar model, including the liquid core equations, was done within the EPM ephemeris. The postfit residuals of LLR observations make evident that the terrestrial models and solutions recommended by the IERS Conventions are compatible with the lunar theory. That includes: EGM2008 gravitational potential with conventional corrections and variations from solid and ocean tides; displacement of stations due to solid and ocean loading tides; and precession-nutation model. Usage of these models in the solution for LLR observations has allowed us to reduce the number of parameters to be fit. The fixed model of tidal variations of the geopotential has resulted in a lesser value of Moon's extra eccentricity rate, as compared to the original DE430 model with two fit parameters. A mixed model of lunar gravitational potential was used, with some coefficients determined from LLR observations, and other taken from the GL660b solution obtained from the GRAIL spacecraft mission. Solutions obtain accurate positions for the ranging stations and the five retroreflectors. Station motion is derived for sites with long data spans. Dissipation is detected at the lunar fluid core-solid mantle boundary demonstrating that a fluid core is present. Tidal dissipation is strong at both Earth and Moon. Consequently, the lunar semimajor axis is expanding by 38.20 mm/yr, the tidal acceleration in mean longitude is -25.90 {{}^' ' }}/cy^2 , and the eccentricity is increasing by 1.48× 10^{-11} each year.
Mancini, L; Littlefair, S P; Southworth, J; Bozza, V; Damasso, M; Dominik, M; Hundertmark, M; Jorgensen, U G; Juncher, D; Popovas, A; Rabus, M; Rahvar, S; Schmidt, R W; Skottfelt, J; Snodgrass, C; Sozzetti, A; Alsubai, K; Bramich, D M; Novati, S Calchi; Ciceri, S; D'Ago, G; Jaimes, R Figuera; Galianni, P; Gu, S -H; Harpsoe, K; Haugbolle, T; Henning, Th; Hinse, T C; Kains, N; Korhonen, H; Scarpetta, G; Starkey, D; Surdej, J; Wang, X -B; Wertz, O
2015-01-01
Context. Photometric monitoring of the variability of brown dwarfs can provide useful information about the structure of clouds in their cold atmospheres. The brown-dwarf binary system Luhman 16AB is an interesting target for such a study, as its components stand at the L/T transition and show high levels of variability. Luhman 16AB is also the third closest system to the Solar system, allowing precise astrometric investigations with ground-based facilities. Aims. The aim of the work is to estimate the rotation period and study the astrometric motion of both components. Methods. We have monitored Luhman 16AB over a period of two years with the lucky-imaging camera mounted on the Danish 1.54m telescope at La Silla, through a special i+z long-pass filter, which allowed us to clearly resolve the two brown dwarfs into single objects. An intense monitoring of the target was also performed over 16 nights, in which we observed a peak-to-peak variability of 0.20 \\pm 0.02 mag and 0.34 \\pm 0.02 mag for Luhman 16A and 1...
Pavlov, Dmitry A; Suvorkin, Vladimir V
2016-01-01
The aim of this work is to combine the model of orbital and rotational motion of the Moon developed for DE430 with up-to-date astronomical, geodynamical, and geo- and selenophysical models. The parameters of the orbit and physical libration are determined in this work from LLR observations made at different observatories in 1970-2013. Parameters of other models are taken from solutions that were obtained independently from LLR. A new implementation of the DE430 lunar model, including the liquid core equations, was done within the EPM ephemeris. The postfit residuals of LLR observations make evident that the terrestrial models and solutions recommended by the IERS Conventions are compatible with the lunar theory. That includes: EGM2008 with conventional corrections and variations from solid and ocean tides; displacement of stations due to solid and ocean loading tides; and precession-nutation model. Usage of these models in the solution for LLR observations has allowed us to reduce the number of parameters to ...
Otsuka, H. [Kyushu University, Fukuoka (Japan). Faculty of Engineering; Kanda, M. [Ministry of Construction, Tokyo (Japan); Suzuki, M. [Tohoku University, Sendai (Japan); Kawakami, M. [Nippon Engineering Consultant Co. Ltd., Tokyo (Japan)
1997-07-21
Several skewed bridges were slid and fell down from their supports by the 1995 Hyogo-Ken Nanbu Earthquake. The purpose of this paper is to study the in-plane rotational behaviour of the skewed bridges after failure of side blocks of the bearing by the horizontal ground motion. Firstly, geometric configuration of the skewed bridges in which the rotation is inevitable is investigated. Then, the rotational displacement of the skewed bridges are obtained by conducting non- linear time- history analyses in which a friction type hysteresis model is assumed to simulate the sliding of the bridge at the supports. It is found that the skewed bridges with small width-span ratios and small skew angles may have considerable sliding rotational displacements and fall down from their supports if adequate seat width is not provided. The requirement of the support length in skewed bridges is also presented. 6 refs., 20 figs., 5 tabs.
Kalkan, Erol; Kwong, Neal S.
2012-01-01
According to regulatory building codes in United States (for example, 2010 California Building Code), at least two horizontal ground-motion components are required for three-dimensional (3D) response history analysis (RHA) of buildings. For sites within 5 km of an active fault, these records should be rotated to fault-normal/fault-parallel (FN/FP) directions, and two RHA analyses should be performed separately (when FN and then FP are aligned with the transverse direction of the structural axes). It is assumed that this approach will lead to two sets of responses that envelope the range of possible responses over all nonredundant rotation angles. This assumption is examined here using a 3D computer model of a six-story reinforced-concrete instrumented building subjected to an ensemble of bidirectional near-fault ground motions. Peak responses of engineering demand parameters (EDPs) were obtained for rotation angles ranging from 0° through 180° for evaluating the FN/FP directions. It is demonstrated that rotating ground motions to FN/FP directions (1) does not always lead to the maximum responses over all angles, (2) does not always envelope the range of possible responses, and (3) does not provide maximum responses for all EDPs simultaneously even if it provides a maximum response for a specific EDP.
Mauldin, Rebecca H.
2010-01-01
In order to study and control the attitude of a spacecraft, it is necessary to understand the natural motion of a body in orbit. Assuming a spacecraft to be a rigid body, dynamics describes the complete motion of the vehicle by the translational and rotational motion of the body. The Simulink Attitude Analysis Model applies the equations of rigid body motion to the study of a spacecraft?s attitude in orbit. Using a TCP/IP connection, Matlab reads the values of the Remote Manipulator System (RMS) hand controllers and passes them to Simulink as specified torque and impulse profiles. Simulink then uses the governing kinematic and dynamic equations of a rigid body in low earth orbit (LE0) to plot the attitude response of a spacecraft for five seconds given known applied torques and impulses, and constant principal moments of inertia.
Daniel Baldovin
2012-09-01
Full Text Available The hunting motion of railway vehicles is a coupled lateral and yaw self-oscillatory motion which is largely determined by wheel–rail contact geometry. The stability of this motion is an important dynamic problem, depends of the railway vehicles speed and determines the maximum operating speed of the vehicles. To improve the stability performances, without increasing the rail-wheel interaction forces above safety limits, elastic joints and dissipative devices are used to connect the wheelset to the bogie frame. In this paper is studied the influence of the wheel conicity and the creep force coefficients to the hunting motion stability of a dynamical system with 10 DOF representing a bogie with independently rotating wheelsets
Miller, E. F., II; Graybiel, A.
1973-01-01
Motion sickness susceptibility of four normal subjects was measured in terms of duration of exposure necessary to evoke moderate malaise (MIIA) as a function of velocity in a chair rotated about a central axis tilted 10 deg with respect to gravitational upright. The subjects had little or no susceptibility to this type of rotation at 2.5 and 5.0 rpm, but with further increases in rate, the MIIA endpoint was always reached and with ever shorter test durations. Minimal provocative periods for all subjects were found at 15 or 20 rpm. Higher rotational rates dramatically reversed the vestibular stressor effect, and the subjects as a group tended to reach a plateau of relatively low susceptibility at 40 and 45 rpm. At these higher velocities, furthermore, the subjects essentially lost their sensation of being tilted off vertical. In the second half of the study, the effect of tilt angle was varied while the rotation rate was maintained at a constant 17.5 rpm. Two subjects were completely resistant to symptoms of motion sickness when rotated at 2.5 deg off vertical; with greater off-vertical angles, the susceptibility of all subjects increased sharply at first, then tapered off in a manner reflecting a Fechnerian function.
Chernodub, M N
2012-01-01
Recently, we have demonstrated that for a certain class of Casimir-type systems ("devices") the energy of zero-point vacuum fluctuations reaches its global minimum when the device rotates about certain axis rather than remains static. This rotational vacuum effect may lead to emergence of permanently rotating objects - philosophically similar to "time crystals" proposed recently by Shapere and Wilczek in classical and quantum mechanical systems - provided the negative rotational energy of zero-point fluctuations cancels the positive rotational energy of the device itself. In this paper we show that for massless electrically charged particles the rotational vacuum effect should be drastically (astronomically) enhanced in the presence of magnetic field. As an illustration, we show that in a background of experimentally available magnetic fields the zero-point energy of massless excitations in rotating torus-shaped doped carbon nanotubes may indeed overwhelm the classical energy of rotation for certain angular f...
Pion-nucleon scattering in the Skyrme model and the P-wave Born amplitudes
We treat fluctuating pion fields around a rotating Skyrmion by means of Dirac's quantization method. The rotational collective motion of the Skyrmion is described by collective coordinates, and conventional gauge-fixing conditions are imposed. Taking into account all the relevant terms at the tree level appearing in the Hamiltonian, we show that pion-nucleon scattering amplitudes exhibit the P-wave Born amplitudes attributed to the Yukawa coupling of order √Nc , which is consistent with the prediction of chiral symmetry such as the Adler-Weisberger relation. This resolves the difficulty that the Skyrme model predicts a wrong Nc dependence for the coupling of order Nc-3/2
Xinning Li
2015-12-01
Full Text Available Normal hip range of motion (ROM is essential in running and transfer of energy from lower to upper extremities during overhead throwing. Dysfunctional hip ROM may alter lower extremity kinematics and predispose athletes to hip and groin injuries. The purpose of this study is characterize hip internal/external ROM (Arc and its effect on the risk of hip, hamstring, and groin injuries in professional baseball players. Bilateral hip internal and external ROM was measured on all baseball players (N=201 in one professional organization (major and minor league during spring training. Players were organized according to their respective positions. All injuries were documented prospectively for an entire MLB season (2010 to 2011. Data was analyzed according to position and injuries during the season. Total number of players (N=201 with an average age of 24±3.6 (range=17-37. Both pitchers (N=93 and catchers (N=22 had significantly decreased mean hip internal rotation and overall hip arc of motion compared to the positional players (N=86. Players with hip, groin, and hamstring injury also had decreased hip rotation arc when compared to the normal group. Overall, there is a correlation between decreased hip internal rotation and total arc of motion with hip, hamstring, and groin injuries.
Rotative balance of the I.M.F. Lille and associated experimental techniques
Verbrugge, R.
1981-01-01
The study of aerodynamic effects at high incidence associated with motions of wide amplitude incorporating continuous rotations requires the consideration of coupled effects, which are generally nonlinear, in a formulation of equations of motion. A rotative balance designed to simulate such maneuvers in a windtunnel was created to form a test medium for analytical studies. A general description of the assembly is provided by considering two main ranges of application. The capacities and performance of the assembly are discussed.
Dang, G. Do; De Klein, A.; Walet, N. R.
1999-01-01
The goal of the present account is to review our efforts to obtain and apply a ``collective'' Hamiltonian for a few, approximately decoupled, adiabatic degrees of freedom, starting from a Hamiltonian system with more or many more degrees of freedom. The approach is based on an analysis of the classical limit of quantum-mechanical problems. Initially, we study the classical problem within the framework of Hamiltonian dynamics and derive a fully self-consistent theory of large amplitude collect...
Nakanishi, Hiroyuki; Sakai, Nobuyuki; Kurayama, Tomoharu; Matsuo, Mitsuhiro; Imai, Hiroshi; Burns, Ross A.; Ozawa, Takeaki; Honma, Mareki; Shibata, Katsunori M.; Kawaguchi, Noriyuki
2015-08-01
We conducted astrometric very long baseline interferometry (VLBI) observations of water-vapor maser emission in the massive star-forming region IRAS 21379+5106 in order to measure the annual parallax and proper motion, using VLBI Exploration of Radio Astrometry (VERA). The annual parallax measured 0.262 ± 0.031 mas, corresponding to a distance of 3.82^{+0.51}_{-0.41}kpc. The proper motion was (μαcos δ, μδ) = (-2.74 ± 0.08, -2.87 ± 0.18) mas yr-1. By using this result, the Galactic rotational velocity was estimated to be Vθ = 218 ± 19 km s-1 at the galactocentric distance R = 9.22 ± 0.43 kpc, when we adopted the Galactic constants R0 = 8.05 ± 0.45 kpc and V0 = 238 ± 14 km s-1. With the newly determined distance, the bolometric luminosity of the central young stellar object was reestimated to be (2.15 ± 0.54) × 103 L⊙, which corresponds to the spectral type of B2-B3. The maser features were found to be distributed along a straight line extending from the southwest to the northeast. In addition, a vector map of the internal motions, constructed from the residual proper motions, implies that the maser features trace a bipolar flow, and that it cannot be explained by simple ballistic motions.
Mazeh, Tsevi; Shporer, Avi
2014-01-01
Some transiting planets discovered by the Kepler mission display transit timing variations (TTVs) induced by stellar spots that rotate on the visible hemisphere of their parent stars. A TTV can be derived when a planet crosses a spot, modifying the shape of the transit light curve. We present an approach that can, in principle, use the derived TTVs of a planet to distinguish between a prograde and a retrograde planetary motion with respect to the stellar rotation. Assuming a single spot darker than the stellar disc, spot crossing by the planet can induce measured positive (negative) TTV, if the crossing occurs in the first (second) half of the transit. On the other hand, the motion of the spot towards (away from) the center of the stellar visible disc causes the stellar brightness to decrease (increase). Therefore, for a planet with prograde motion, the TTV is positive when the local slope of the stellar flux at the time of transit is negative, and vice versa. Using a simplistic model we show that TTVs induce...
Two large-amplitude motions in triatomic molecules. Force field of the 1B2 (1A') state of SO2
Mezey, Paul G.; Ramachandra Rao, Ch. V. S.
1980-01-01
A program has been developed to calculate the energy levels associated with the two large-amplitude stretching vibrations ν1 and ν3 of a bent triatomic molecule in which the ν3 oscillation occurs in a double minimum potential. Employing the two large-amplitude Hamiltonian H0s(ρ1,ρ3) obtained earlier by Brand and Rao. [J. Mol. Spectrosc., 61, 360 (1976)], the vibrational energy levels (v1,v3even/odd) of SO2 molecule in its 1B2 (1A') excited state are calculated. The nine parameters of the potential function V0(ρ1,ρ3) are then adjusted to give a least-square fit to the 12 observed vibrational term values corresponding to the levels (v1,v3even) of S16O2 and S18O2. A three-dimensional picture of the potential surface V0(ρ1,ρ3) using the final set of force constants is also presented. The saddle point of this surface is at (ρO1=1.5525 Å, ρO3=0.0 Å) and the absolute minima occur at (ρe1=1.5644 Å, ρe3=±0.0745 Å). Barrier height, i.e., the height of the saddle point above the absolute minima, is 140 cm-1.
Brokešová, J.; Málek, Jiří
2015-01-01
Roč. 19, č. 2 (2015), s. 491-509. ISSN 1383-4649 R&D Projects: GA ČR GAP210/10/0925; GA MŠk LM2010008; GA ČR GA15-02363S Institutional support: RVO:67985891 Keywords : seismic rotation * near-source region * rotation-to-translation relations * numerical simulations * S-wave velocity Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.386, year: 2014
Soung-Yob Rhi
2014-02-01
Full Text Available We aimed to analyze the range of motion (ROM and internal rotation (IR and external rotation (ER isokinetic strength according to humeral retroversion of the dominant shoulder.We included 40 elite baseball players in Korea (OBP group: n=20 players with careers spanning >10 years, age: 19.37±2.21 years, height: 181.00±5.41 cm, weight: 84.58±7.85 kg; BBP group: n=20 players with careers spanning 10 years had significantly higher humeral retroversion, IROM, EROM, and IR and ER isokinetic strength of the dominant shoulder than youth players with careers spanning <10 years. Furthermore, humeral retroversion and ROM were not significantly related, but IR and ER isokinetic strength were significantly positively related with retroversion in both groups.
Pulsation-driven mean zonal and meridional flows in rotating massive stars
Lee, Umin; Neiner, Coralie
2015-01-01
Zonal and meridional axisymmetric flows can deeply impact the rotational and chemical evolution of stars. Therefore, momentum exchanges between waves propagating in stars, differential rotation, and meridional circulation must be carefully evaluated. In this work, we study axisymmetric mean flows in rapidly and initially uniformly rotating massive stars driven by small amplitude non-axisymmetric $\\kappa$-driven oscillations. We treat them as perturbations of second-order of the oscillation amplitudes and derive their governing equations as a set of coupled linear ordinary differential equations. This allows us to compute 2-D zonal and meridional mean flows driven by low frequency $g$- and $r$-modes in slowly pulsating B (SPB) stars and $p$-modes in $\\beta$ Cephei stars. Oscillation-driven mean flows usually have large amplitudes only in the surface layers. In addition, the kinetic energy of the induced 2-D zonal rotational motions is much larger than that of the meridional motions. In some cases, meridional f...
Chaos and Fractals in Geodesic Motions Around a Non-Rotating Black-Hole with an External Halo
Servio de Moura, A P; Moura, Alessandro P. S. de; Letelier, Patricio S.
1999-01-01
We investigate the occurrence chaos in the escape of test particles moving in the field of a Schwarzschild black hole surrounded by an external halo. The motion of both material particles and zero rest mass particles is considered. The chaos is characterized by the fractal dimension of boundary between the basins of the different escapes, which is a topologically invariant characterization. We find chaos in the motion of both material particles and null geodesics.
Sugiyama, K; Doi, A; Honma, M; Kobayashi, H; Murata, Y; Motogi, K; Niinuma, K; Ogawa, H; Wajima, K; Sawada-Satoh, S; Ellingsen, S P
2013-01-01
We have measured the internal proper motions of the 6.7 GHz methanol masers associated with Cepheus A (Cep A) HW2 using Very Long Baseline Interferometery (VLBI) observations. We conducted three epochs of VLBI monitoring observations of the 6.7 GHz methanol masers in Cep A-HW2 with the Japanese VLBI Network (JVN) over the period between 2006-2008. In 2006, we were able to use phase-referencing to measure the absolute coordinates of the maser emission with an accuracy of a few milliarcseconds. We compared the maser distribution with other molecular line observations that trace the rotating disk. We measured the internal proper motions for 29 methanol maser spots, of which 19 were identified at all three epochs and the remaining ten at only two epochs. The magnitude of proper motions ranged from 0.2 to 7.4 km/s, with an average of 3.1 km/s. Although there are large uncertainties in the observed internal proper motions of the methanol maser spots in Cep A, they are well fitted by a disk that includes both rotati...
Mazurek, K; Maj, A; Rouvel, D
2013-01-01
We present a theoretical analysis of the competition between so-called nuclear Jacobi and Poincar\\'e shape transitions in function of spin - at high temperatures. The latter condition implies the method of choice - a realistic version of the nuclear Liquid Drop Model (LDM), here: the Lublin-Strasbourg Drop (LSD) model. We address specifically the fact that the Jacobi and Poincar\\'e shape transitions are accompanied by the flattening of total nuclear energy landscape as function of the relevant deformation parameters what enforces large amplitude oscillation modes that need to be taken into account. For that purpose we introduce an approximate form of the collective Schr\\"odinger equation whose solutions are used to calculate the most probable deformations associated with both types of transitions and discuss the physical consequences in terms of the associated critical-spin values and transitions themselves.
Hildreth, Owen J.; Rykaczewski, Konrad; Fedorov, Andrei G.; Wong, Ching P.
2013-01-01
Metal-assisted Chemical Etching of silicon has recently emerged as a powerful technique to fabricate 1D, 2D, and 3D nanostructures in silicon with high feature fidelity. This work demonstrates that out-of-plane rotational catalysts utilizing polymer pinning structures can be designed with excellent control over rotation angle. A plastic deformation model was developed establishing that the catalyst is driven into the silicon substrate with a minimum pressure differential across the catalyst thickness of 0.4-0.6 MPa. Force-displacement curves were gathered between an Au tip and Si or SiO2 substrates under acidic conditions to show that Derjaguin and Landau, Verwey and Overbeek (DLVO) based forces are capable of providing restorative forces on the order of 0.2-0.3 nN with a calculated 11-18 MPa pressure differential across the catalyst. This work illustrates that out-of-plane rotational structures can be designed with controllable rotation and also suggests a new model for the driving force for catalyst motion based on DLVO theory. This process enables the facile fabrication of vertically aligned thin-film metallic structures and scalloped nanostructures in silicon for applications in 3D micro/nano-electromechanical systems, photonic devices, nanofluidics, etc.Metal-assisted Chemical Etching of silicon has recently emerged as a powerful technique to fabricate 1D, 2D, and 3D nanostructures in silicon with high feature fidelity. This work demonstrates that out-of-plane rotational catalysts utilizing polymer pinning structures can be designed with excellent control over rotation angle. A plastic deformation model was developed establishing that the catalyst is driven into the silicon substrate with a minimum pressure differential across the catalyst thickness of 0.4-0.6 MPa. Force-displacement curves were gathered between an Au tip and Si or SiO2 substrates under acidic conditions to show that Derjaguin and Landau, Verwey and Overbeek (DLVO) based forces are capable of
Spontaneous rotation in a driven mechanical system
Alexander, T. J.
2016-06-01
We show that a mass free to circulate around a shaken pivot point exhibits resonance-like effects and large amplitude dynamics even though there is no natural frequency in the system, simply through driving under geometrical constraint. We find that synchronization between force and mass occurs over a wide range of forcing amplitudes and frequencies, even when the forcing axis is dynamically, and randomly, changed. Above a critical driving amplitude the mass will spontaneously rotate, with a fractal boundary dividing clockwise and anti-clockwise rotations. We show that this has significant implications for energy harvesting, with large output power over a wide frequency range. We examine also the effect of driving symmetry on the resultant dynamics, and show that if the shaking is circular the motion becomes constrained, whereas for anharmonic rectilinear shaking the dynamics may become chaotic, with the system mimicking that of the kicked rotor.
Importance of body rotation during the flight of a butterfly
Fei, Yueh-Han John; Yang, Jing-Tang
2016-03-01
In nature the body motion of a butterfly is clearly observed to involve periodic rotation and varied flight modes. The maneuvers of a butterfly in flight are unique. Based on the flight motion of butterflies (Kallima inachus) recorded in free flight, a numerical model of a butterfly is created to study how its flight relates to body pose; the body motion in a simulation is prescribed and tested with varied initial body angle and rotational amplitude. A butterfly rotates its body to control the direction of the vortex rings generated during flapping flight; the flight modes are found to be closely related to the body motion of a butterfly. When the initial body angle increases, the forward displacement decreases, but the upward displacement increases within a stroke. With increased rotational amplitudes, the jet flows generated by a butterfly eject more downward and further enhance the generation of upward force, according to which a butterfly executes a vertical jump at the end of the downstroke. During this jumping stage, the air relative to the butterfly is moving downward; the butterfly pitches up its body to be parallel to the flow and to decrease the projected area so as to avoid further downward force generated. Our results indicate the importance of the body motion of a butterfly in flight. The inspiration of flight controlled with body motion from the flight of a butterfly might yield an alternative way to control future flight vehicles.
Wolf, David A.; Schwarz, Ray P.
1991-01-01
The gravity induced motions, through the culture media, is calculated of living tissue segments cultured in the NASA rotating zero head space culture vessels. This is then compared with the media perfusion speed which is independent of gravity. The results may be interpreted as a change in the physical environment which will occur by operating the NASA tissue culture systems in actual microgravity (versus unit gravity). The equations governing particle motions which induce flows at the surface of tissues contain g terms. This allows calculation of the fluid flow speed, with respect to a cultured particle, as a function of the external gravitational field strength. The analysis is approached from a flow field perspective. Flow is proportional to the shear exerted on a structure which maintains position within the field. The equations are solved for the deviation of a particle from its original position in a circular streamline as a function of time. The radial deviation is important for defining the operating limits and dimensions of the vessel because of the finite radius at which particles necessarily intercept the wall. This analysis uses a rotating reference frame concept.
Rotational coronary angiography provides a multitude of x-ray projections of the contrast agent enhanced coronary arteries along a given trajectory with parallel ECG recording. These data can be used to derive motion information of the coronary arteries including vessel displacement and pulsation. In this paper, a fully automated algorithm to generate 4D motion vector fields for coronary arteries from multi-phase 3D centerline data is presented. The algorithm computes similarity measures of centerline segments at different cardiac phases and defines corresponding centerline segments as those with highest similarity. In order to achieve an excellent matching accuracy, an increasing number of bifurcations is included as reference points in an iterative manner. Based on the motion data, time-dependent vessel surface extraction is performed on the projections without the need of prior reconstruction. The algorithm accuracy is evaluated quantitatively on phantom data. The magnitude of longitudinal errors (parallel to the centerline) reaches approx. 0.50 mm and is thus more than twice as large as the transversal 3D extraction errors of the underlying multi-phase 3D centerline data. It is shown that the algorithm can extract asymmetric stenoses accurately. The feasibility on clinical data is demonstrated on five different cases. The ability of the algorithm to extract time-dependent surface data, e.g. for quantification of pulsating stenosis is demonstrated.
Duncan, Anthony; Pérez, Enric
2016-05-01
We present and discuss an interesting and puzzling problem Ehrenfest found in his first application of the adiabatic hypothesis, in 1913. It arose when trying to extend Planck's quantization of the energy of harmonic oscillators to a rotating dipole within the frame of the old quantum theory. Such an extension seemed to lead unavoidably to half-integral values for the rotational angular momentum of a system (in units of ℏ). We present the problem in its original form along with the (few) responses we have found to Ehrenfest's treatment. After giving a brief account of the classical and quantum adiabatic theorem, we also describe how Quantum Mechanics provides an explanation for this difficulty.
Aso, Yusuke; Saigo, Kazuya; Koyamatsu, Shin; Aikawa, Yuri; Hayashi, Masahiko; Machida, Masahiro N; Saito, Masao; Takakuwa, Shigehisa; Tomida, Kengo; Tomisaka, Kohji; Yen, Hsi-Wei
2015-01-01
We have observed the Class I protostar TMC-1A with Atacama Millimeter/submillimeter Array (ALMA) in 12CO and C18O (J=2-1), and 1.3-mm dust continuum emission. Continuum emission with a deconvolved size of 0.50"x0.37", perpendicular to the 12CO outflow, is detected. It most likely traces a circumstellar disk around TMC-1A, as previously reported. In contrast, a more extended structure is detected in C18O although it is still elongated with a deconvolved size of 3.3"x2.2", indicating that C18O traces mainly a flattened envelope surrounding the disk and the central protostar. C18O shows a clear velocity gradient perpendicular to the outflow at higher velocities, indicative of rotation, while an additional velocity gradient along the outflow is found at lower velocities. The radial profile of the rotational velocity is analyzed in detail, finding that it is given as a power-law \\propto r^{-a} with an index of ~0.5 at higher velocities. This suggests that the rotation at higher velocities can be explained as Keple...
Physics of particles in the rotating tube
Pardy, Miroslav
2011-01-01
The classical and the quantum motion of a massive body in the rotating tube is considered. Photon is included. The spin motion described by the Bargmann-Michel-Telegdi equation is considered in the rotation tube and rotating system.
Power Harvesting from Rotation?
Chicone, Carmen; Feng, Z. C.
2008-01-01
We show the impossibility of harvesting power from rotational motions by devices attached to the rotating object. The presentation is suitable for students who have studied Lagrangian mechanics. (Contains 2 figures.)
Effects of Periodic Forcing Amplitude on the Spiral Wave Resonance Drift
WU Ning-Jie; LI Bing-Wei; YING He-Ping
2006-01-01
@@ We study dynamics of spiral waves under a uniform periodic temporal forcing in an excitable medium. With a specific combination of frequency and amplitude of the external periodic forcing, a resonance drift of a spiral wave occurs along a straight line, and it is accompanied by a complicated ‘flower-like’ motion on each side of this bifurcate boundary line. It is confirmed that the straight-line drift frequency of spiral waves is not locked to the nature rotation frequency as the forcing amplitude expends the range of the spiral wave frequency. These results are further verified numerically for a simplified kinematical model.
Bordag, L A; Froehner, M; Myrnyy, V
2003-01-01
We analyze the stability of a cylindrical Couette flow under the imposition of a weak axial flow in case of a very short cylinder with a narrow annulus gap. We consider an incompressible viscous fluid which is contained in the narrow gap between two concentric short cylinders, where the inner cylinder rotates with constant angular velocity. The caps of the cylinders have narrow tubes conically tapering to super narrow slits which allow for an axial flow along the surface of the inner cylinder. The approximated solution for the Couette flow for short cylinders was found and used for the stability analysis instead of the exact but bulky solution. The sensitivity of the Couette flow to general small perturbations and to the weak axial flow was studied. We demonstrate that perturbations coming from the axial flow cause the propagation of dispersive waves in the Taylor-Couette flow. The coexistence of a rotation and of an axial flow requires to study in addition to the energy and the angular momentum also the heli...
A Micro-Machined Gyroscope for Rotating Aircraft
Fuxue Zhang
2012-07-01
Full Text Available In this paper we present recent work on the design, fabrication by silicon micromachining, and packaging of a new gyroscope for stabilizing the autopilot of rotating aircraft. It operates based on oscillation of the silicon pendulum between two torsion girders for detecting the Coriolis force. The oscillation of the pendulum is initiated by the rolling and deflecting motion of the rotating carrier. Therefore, the frequency and amplitude of the oscillation are proportional to the rolling frequency and deflecting angular rate of the rotating carrier, and are measured by the sensing electrodes. A modulated pulse with constant amplitude and unequal width is obtained by a linearizing process of the gyroscope output signal and used to control the deflection of the rotating aircraft. Experimental results show that the gyroscope has a resolution of 0.008 °/s and a bias of 56.18 °/h.
Nakanishi, Hiroyuki; Kurayama, Tomoharu; Matsuo, Mitsuhiro; Imai, Hiroshi; Burns, Ross A; Ozawa, Takeaki; Honma, Mareki; Shibata, Katsunori; Kawaguchi, Noriyuki
2015-01-01
We conducted astrometric VLBI observations of water-vapor maser emission in the massive star forming region IRAS 21379+5106 to measure the annual parallax and proper motion, using VERA. The annual parallax was measured to be $0.262 \\pm 0.031$ mas corresponding to a trigonometric distance of $3.82^{+0.51}_{-0.41}$ kpc. The proper motion was $(\\mu_\\alpha\\cos{\\delta}, \\mu_\\delta)=(-2.74 \\pm 0.08, -2.87 \\pm 0.18)$ mas yr$^{-1}$. Using this result, the Galactic rotational velocity was estimated to be $V_\\theta=218\\pm 19$ km s$^{-1}$ at the Galactocentric distance $R=9.22\\pm0.43$ kpc, when we adopted the Galactic constants $R_0=8.05\\pm 0.45$ kpc and $V_0=238\\pm 14$ km s$^{-1}$. With newly determined distance, {the bolometric luminosity of the central young stellar object was re-evaluated to $(2.15\\pm 0.54)\\times 10^3 L_\\odot$, which corresponds to spectral type of} B2--B3. Maser features were found to be distributed along a straight line from south-west to north-east. In addition, a vector map of the internal motio...
Stochastic aspects of large amplitude collective motion
We consider externally driven many-body systems with complex spectra of intrinsic states. The effects of the coupling to the external world are analyzed by assuming time dependent random matrix properties for the intrinsic system. We derive and solve evolution equations for intrinsic state population probabilities, average excitation energy and its fluctuations. The diffusive process is likely dominated by memory effects and an unexpected type of fluctuations
Stochastic aspects of large amplitude collective motion
We consider externally driven many-body systems with complex spectra of intrinsic states. The effects of the coupling to the external world are analyzed by assuming time-dependent random matrix properties for the intrinsic system. We derive and solve evolution equations for intrinsic state population probabilities, average excitation energy and its fluctuations. The diffusive process is likely to be dominated by memory effects and an unexpected type of fluctuations. (orig.)