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1
Morrish, L., M. P. Cartmell, and A. J. Taylor. "Geometry and kinematics of multicable spreader lifting gear." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 211, no. 3 (1997): 185–94. http://dx.doi.org/10.1243/0954406971521764.
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This paper presents a novel theoretical study of the geometry and derived kinematics of a typical multicable suspension system as encountered on a rubber tyred gantry (RTG) crane. Machines of this sort are used extensively in the international container handling business but, to date, little has been known about the precise motions of cable suspended spreaders other than general intuitions about fore—aft, lateral and rotational oscillations. Such motions are initiated by driver-controlled motion of the gantry itself (by torques applied to the driving wheels) and by across-the-vehicle motions of the trolley from which the spreader and container payload are suspended. The work reported here shows the complete derivation for spreader coordinates, relative to the trolley, for any translational and/or rotational displacement. Conventional geometrical and trigonometrical principles are used throughout the development. This research forms an integral part of a larger programme of work to propose strategies for accurate spreader motion control based on non-linear dynamic models.
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Aribowo, Wisnu, Takahito Yamashita, and Kazuhiko Terashima. "Integrated Trajectory Planning and Sloshing Suppression for Three-Dimensional Motion of Liquid Container Transfer Robot Arm." Journal of Robotics 2015 (2015): 1–15. http://dx.doi.org/10.1155/2015/279460.
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For liquid transfer system in three-dimensional space, the use of multijoint robot arm provides much flexibility. To realize quick point-to-point motion with minimal sloshing in such system, we propose an integrated framework of trajectory planning and sloshing suppression. The robot motion is decomposed into translational motion of the robot wrist and rotational motion of the robot hand to ensure the upright orientation of the liquid container. The trajectory planning for the translational motion is based on cubic spline optimization with free via points that produces smooth trajectory in joint space while it still allows obstacle avoidance in task space. Input shaping technique is applied in the task space to suppress the motion induced sloshing, which is modeled as spherical pendulum with moving support. It has been found through simulations and experiments that the proposed approach is effective in generating quick motion with low amount of sloshing.
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Chelluru, Venkata Surya Rajesh, and Venkatesh Narise. "Multi Joint Robot Transfer System in Three Dimensional Space." International Journal of Trend in Scientific Research and Development 2, no. 1 (2017): 1132–33. https://doi.org/10.31142/ijtsrd7192.
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Transfer system in three dimensional space, the use of multi joint robot arm provides much flexibility. To realize quick point to point motion with minimal sloshing in such system, we propose an integrated framework of trajectory planning and sloshing suppression. The robot motion is decomposed into translational motion of the robot wrist and rotational motion of the robot hand to ensure the upright orientation of the liquid container. The trajectory planning for the translational motion is based on cubic spline optimization with free via points that produces smooth trajectory in joint space while it still allows obstacle avoidance in task space. Input shaping technique is applied in the task space to suppress the motion induced sloshing, which is modeled as spherical pendulum with moving support. It has been found through simulations and experiments that the proposed approach is effective in generating quick motion with low amount of sloshing. Chelluru Venkata Surya Rajesh | Narise Venkatesh "Multi-Joint Robot Transfer System in Three Dimensional Space" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-1 , December 2017, URL: https://www.ijtsrd.com/papers/ijtsrd7192.pdf
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Leonid, Kutsenko, Vanin Volodymyr, Naidysh Andrii, et al. "DEVELOPMENT OF A GEOMETRIC MODEL OF A NEW METHOD FOR DELIVERING EXTINGUISHING SUBSTANCES TO A DISTANT FIRE ZONE." Eastern-European Journal of Enterprise Technologies 4, no. 7 (106) (2020): 88–102. https://doi.org/10.15587/1729-4061.2020.209382.
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A geometric model of a new method of delivering fire-extinguishing substances to a fire zone located at a considerable distance was offered. The idea of delivery is based on the mechanical action of throwing. To this end, a substance (e.g. extinguishing powder) is loaded in a hard shell made as a special container. After delivery by means of a launcher to a fire zone, the container has to release the substance which will promote fire extinguishing. The known method of remote delivery of extinguishing substances uses a pneumatic gun with a cylindrical container. During delivery, the cylinder must rotate around its axis to ensure flight stability. The cylinder is rotated by a special turbine when passing through the gun barrel. There are difficulties in regulating the distribution of compressed air flows during the turbine operation. In addition, the tightness of the pneumatic part of the gun should be monitored. The new delivery method uses a container in a form of two spaced loads similar to a sports dumbbell. The dumbbell motion is initiated by simultaneous action of explosion-generated pulses directed at each of its loads in a pre-calculated manner. This results in the rotational motion of the container. To describe the dynamics of the dumbbell motion, a Lagrangian was defined and a system of Lagrange differential equations of the second kind was set up and solved. Examples of modeling trajectories of the centers of masses of the dumbbell loads taking into account air resistance were given. The proposed method is planned to be a basis of a new fire extinguishing technology. This is evidenced by the new scheme of launching the dumbbell by means of explosion-generated pulses of charges of two pyro cartridges. The obtained results make it possible to estimate magnitudes of explosion-generated pulses necessary for throwing and corresponding distances of the dumbbell delivery
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Reinwald, Michael, Moritz Bernauer, Heiner Igel, and Stefanie Donner. "Improved finite-source inversion through joint measurements of rotational and translational ground motions: a numerical study." Solid Earth 7, no. 5 (2016): 1467–77. http://dx.doi.org/10.5194/se-7-1467-2016.
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Abstract. With the prospects of seismic equipment being able to measure rotational ground motions in a wide frequency and amplitude range in the near future, we engage in the question of how this type of ground motion observation can be used to solve the seismic source inverse problem. In this paper, we focus on the question of whether finite-source inversion can benefit from additional observations of rotational motion. Keeping the overall number of traces constant, we compare observations from a surface seismic network with 44 three-component translational sensors (classic seismometers) with those obtained with 22 six-component sensors (with additional three-component rotational motions). Synthetic seismograms are calculated for known finite-source properties. The corresponding inverse problem is posed in a probabilistic way using the Shannon information content to measure how the observations constrain the seismic source properties. We minimize the influence of the source receiver geometry around the fault by statistically analyzing six-component inversions with a random distribution of receivers. Since our previous results are achieved with a regular spacing of the receivers, we try to answer the question of whether the results are dependent on the spatial distribution of the receivers. The results show that with the six-component subnetworks, kinematic source inversions for source properties (such as rupture velocity, rise time, and slip amplitudes) are not only equally successful (even that would be beneficial because of the substantially reduced logistics installing half the sensors) but also statistically inversions for some source properties are almost always improved. This can be attributed to the fact that the (in particular vertical) gradient information is contained in the additional motion components. We compare these effects for strike-slip and normal-faulting type sources and confirm that the increase in inversion quality for kinematic source parameters is even higher for the normal fault. This indicates that the inversion benefits from the additional information provided by the horizontal rotation rates, i.e., information about the vertical displacement gradient.
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OLUSEGUN, Samuel Dare, OLUSEGUN, Samuel Dare, ELAKPA Ada Augustine ELAKPA Ada Augustine, ORJI, Charles U. ORJI, Charles U, and TAMUNODUKOBIPI, Daniel TAMUNODUKOBIPI, Daniel. "Simulation of a Container Vessel Using Boundary Element Method for the Computation of Hydrodynamic Pressure and Forces." International Journal of Advances in Engineering and Management 06, no. 12 (2024): 241–48. https://doi.org/10.35629/5252-0612241248.
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This study presents a comprehensive analysis of the hydrodynamic behavior of a containership under varying wave conditions using the Boundary Element Method (BEM). The hydrodynamic pressure distribution, as derived from BEM simulations, highlights critical pressure zones on the vessel’s hull, with maximum pressures reaching approximately 160 N/mm² near the bow. These high-pressure regions, caused by direct wave impacts, emphasize the structural vulnerability to fatigue, underscoring the need for reinforced designs in areas subjected to repeated loading. Additionally, the pressure mapping reveals patterns that align with expected wave-induced behaviors, validating the effectiveness of the BEM in capturing critical load distributions. The analysis also investigates wave excitation forces and diffraction/Froude-Krylov forces across six motion modes (surge, sway, heave, roll, pitch, and yaw). Translational modes exhibit peak forces of up to 8000 N at low wave frequencies (~0.1 Hz), while rotational modes encounter forces as high as 10^8 N, particularly in roll and pitch. These findings highlight the influence of wave characteristics, such as frequency and angle, on vessel stability and structural stress. The results provide valuable insights for vessel design and operational planning, advocating for enhanced stabilization systems, optimized structural reinforcements, and improved cargo placement strategies to ensure safety, performance, and longevity under various sea conditions.
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Karpunin, I. E., N. V. Kozlov, and A. R. Zimasova. "Dynamics of phase inclusion during rotational oscillations of simply connected annulus." Journal of Physics: Conference Series 2317, no. 1 (2022): 012005. http://dx.doi.org/10.1088/1742-6596/2317/1/012005.
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Abstract The dynamics of a phase inclusion in a coaxial liquid layer divided with a radial partition is studied experimentally. The working volume of the container is filled with a viscous liquid, inside which an air bubble, immiscible with the main phase, is injected. This inclusion has a lower density than the surrounding liquid does. The container performs rotational oscillations as a whole with the zero average rotation. Such a motion brings to the generation of a harmonically oscillating azimuthal shear flow, which, as a consequence, excites the oscillations of the phase inclusion. During the bubble’s oscillations, the displacement of its geometric center follows the sinusoidal law. On the background of such a motion a periodic deformation of the bubble is observed, i.e. the phase boundary starts oscillating. A new and surprising result of the experiments is found, when the light bubble sinks and takes a quasi-steady position near the inner wall of the layer.
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Vatulia, Glib, Alyona Lovska, and Yevhen Krasnokutskyi. "Mathematical modeling of the vertical load of a hopper-type container placed on a long-base structure of a platform car." Bulletin of the National Technical University «KhPI» Series: Dynamics and Strength of Machines, no. 1 (December 31, 2022): 34–39. http://dx.doi.org/10.20998/2078-9130.2022.1.264323.
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Higher operational efficiency of container transportation can be achieved by putting into operation hopper containers. The special feature of a container is its inclined end and sidewalls, which makes it possible to self-discharge bulk freight through the discharging hatches forming the floor. The vertical loading of a hopper container placed on the long-base flat car was determined with the mathematical modelling. The mathematical model described the translational movement of a flat car in the vertical plane, i.e. bouncing oscillations. The flat car for the calculation consisted of three bodies: bearing structure loaded with four containers and two 18-100 bogies. The containers were considered as attached masses that completely repeated the movement pattern of the bearing structure of the flat car in the vertical plane. The mathematical model also included the elastic characteristics of the track. The calculation was made for the containers placed on a long-base 13-7024 flat car. The mathematical model was solved with the Runge-Kutta method in MathCad. The initial conditions were equal to zero. It was found that the maximum acceleration in the mass center of the bearing structure of a flat car loaded with hopper containers was 1.28 m/s2, which did not exceed the allowable values. The vertical dynamic coefficient was 0.13. The motion of the flat car was estimated as excellent.The results of the research will be of value for those who are dealing with development of advanced container structures with better operational efficiency for container transportation.Key words: transport mechanics, hopper container, dynamic loading, dynamic characteristics, container transportation.
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Xin, Yida, Taili Du, Changhong Liu, Zhiyuan Hu, Peiting Sun, and Minyi Xu. "A Ring-Type Triboelectric Nanogenerator for Rotational Mechanical Energy Harvesting and Self-Powered Rotational Speed Sensing." Micromachines 13, no. 4 (2022): 556. http://dx.doi.org/10.3390/mi13040556.
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In recent years, sensors have been moving towards the era of intelligence, miniaturization and low power consumption, but the power-supply problem has always been a key issue restricting the popularization and development of machine-mounted sensors on the rotating machinery. Herein, we develop a ring-type triboelectric nanogenerator (R-TENG) that functions as a sustainable power source as well as a self-powered rotational speed sensor for rotating machinery. The R-TENG adopts a freestanding mode and consists of a ring-type container unit, an end cover and polytetrafluoroethylene (PTFE) cylinders. In this study, the influence of the number of cylinders, the PTFE cylinder’s diameter and the rotational speed on the electrical output are systematically examined, and the motion law of the PTFE cylinders in the container is revealed by the experimental results and verified by kinetic simulation. At a rotational speed of 400 rpm, the output voltage, current and transferred charge of the designed R-TENG reached 138 V, 115 nC and 2.03 μA, respectively. This study provides an attractive power supply strategy for machine-mounted sensors of the rotating machinery, and the rotational speed measurement test also suggests the potential application of the R-TENG as a self-powered rotational speed sensor.
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Kalinovskyi, Andrii. "ENGINEERING METHOD FOR MODELING THE OUTER BALLISTICS OF ROTATIONAL AND PROGRESSIVE MOVEMENT DUMBBELLS." APPLIED GEOMETRY AND ENGINEERING GRAPHICS, no. 100 (May 24, 2021): 126–38. http://dx.doi.org/10.32347/0131-579x.2021.100.126-138.
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The work is devoted to the method of delivering a fire extinguishing agent into a distant fire zone. In a known method, a substance (for example, a fire extinguishing powder) is placed in a solid shell - a cylindrical container. After delivery to the location of the fire, the container should collapse and free up the substance that will be assisted on fire extinguishing. A pneumatic gun is used to deliver a cylindrical container. In the process of delivery, the cylinder should rotate around its axis to ensure the stability of the movement. At the same time, during the "shot", the difficulty of regulating the distribution of compressed air flows in the gun dulk to achieve the required speed of rotation of the cylinder is arisen.
 In a new delivery method, it is proposed to use a container consisting of two spherical containers connected by a rod (like dumbbells). Traditional motion modeling Dumbbells is based on the preparation and solution of the system of differential equations of Lagrange of the second kind. To do this, choose the functions of generalized coordinates and use Lagrangian to describe the rotational and progressive movement of dumbbells in the earth's field. This allows you to obtain approximate functional dependences, as well as dependencies of derivatives for each of the functions of generalized coordinates. As a result, you can depict charts of phase trajectories of the generalized coordinates. The dependence on time for the functions of generalized coordinates allow you to simulate the outer ballistics dumbbells - i.e. Create a computer animation of its rotational and progressive movement.
 In contrast to the traditional approach in this paper, an engineering method of geometric modeling of the external ballistics of the movement of dumbbells is proposed. Those. The method of modeling the rotational and progressive movement dumbbells, which is based on geometric representations. We assume that the auxiliary circle is rigidly fixed on the dumbbells, the center of which coincides with the center of mass dumbbells. Let the circle "quoted" along the ballistic trajectory of the Mass Dumbbell Center. Then the trajectories of the point mass of cargo dumbbells will give an approximate view of the rotational and progressive movement of dumbbells into spacious within the vertical plane.
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Raynovskyy, Ihor, and Alexander Timokha. "Steady-State Resonant Sloshing in an Upright Cylindrical Container Performing a Circular Orbital Motion." Mathematical Problems in Engineering 2018 (June 28, 2018): 1–8. http://dx.doi.org/10.1155/2018/5487178.
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The nonlinear Narimanov-Moiseev multimodal equations are used to study the swirling-type resonant sloshing in a circular base container occurring due to an orbital (rotary) tank motion in the horizontal plane with the forcing frequency close to the lowest natural sloshing frequency. An asymptotic steady-state solution is constructed and the response amplitude curves are analyzed to prove their hard-spring type behavior for the finite liquid depth (the mean liquid depth-to-the-radius ratio h>1). This behavior type is supported by the existing experimental data. The wave elevations at the vertical wall are satisfactorily predicted except for a frequency range where the model test observations reported wave breaking and/or mean rotational flows.
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Bubenchikov, Alexey M., Mikhail A. Bubenchikov, Anna S. Chelnokova, Dmitriy V. Mamontov, and Alexander V. Lun-Fu. "Fullerene Movement in a Carbon Nanocontainer." Crystals 12, no. 8 (2022): 1179. http://dx.doi.org/10.3390/cryst12081179.
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The character of C60 fullerene motion inside a cylindrical carbon nanocontainer with flat graphene covers has been studied. A new trajectory approach to describe the three-dimensional motion of fullerene is presented, based on the use of motion equations for its center of mass in the field of van der Waals forces, as well as the rotational motion equations written in the absolute basis. A high-precision computational technology for implementing this approach is described. Calculations have shown the components of the C60 angular velocity change stepwise. This character of the change in rotation is determined by the impacts of the fullerene on the wall of the container. As a result of these impacts, the energy of rotation changes abruptly.
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Han, Mengmeng, Jian Dai, C. M. Wang, and K. K. Ang. "Hydrodynamic Analysis of Partially Filled Liquid Tanks Subject to 3D Vehicular Manoeuvring." Shock and Vibration 2019 (November 27, 2019): 1–14. http://dx.doi.org/10.1155/2019/6943879.
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This paper is concerned with liquid sloshing in a partially filled container due to 3-dimensional vehicle motion. The liquid sloshing is described by a set of linear modal equations derived from the potential flow theory, which can be applied to liquid sloshing induced by arbitrary combination of lateral, longitudinal, and rotational excitations. The sloshing force and moment are expressed with a set of hydrodynamic coefficients that are determined by the linear velocity potential. These coefficients can be precalculated and incorporated into the motion equations of the vehicle system so that a fully coupled vehicle-sloshing model is available. In addition, we propose an approach to calculate the hydrodynamic coefficients using the outputs of commercial frequency-domain boundary element software in order to maximize the efficiency of modelling and computation. The accuracy of the proposed model is examined by comparison with available CFD and model test data in the literature. The case of a road tanker encountering a road bump during acceleration/braking is investigated. Results show that the tank rotational motion will affect the amplitude and the sloshing force, and neglecting tank rotation may lead to underestimation of the sloshing force magnitude.
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Morrish, L., M. P. Cartmell, and A. J. Taylor. "Cable Stretch Asymmetries in Multi-Cable Spreader Suspension Systems Undergoing Combined Translations and Rotations." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 210, no. 3 (1996): 225–37. http://dx.doi.org/10.1243/pime_proc_1996_210_192_02.
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The work presented in this paper proposes that for widely spaced cable reeving configurations in container-handling cranes there is an interesting, and unexpectedly useful, phenomenon defined henceforth as geometrical extension which gives rise to unevenly distributed cable stretch and, hence, uneven tensions across the system. Geometrical extension is entirely caused by the reluctance of the trolley, spreader and cable system to conform, as a whole, to certain overall shapes. Such shapes are developed because of the various translational and rotational motions which can be experienced at the trolley (that is at the attachment point of the cables running down to the spreader). Other cables stretch effects, such as those due to static and dynamic (inertia) loads, are additional to the geometrical extension (which can, in some circumstances, manifest as a compression instead). The net effect of cable stretch asymmetries is to stiffen up the suspension for certain cases of translation and rotation. This has a direct, and useful, influence for anti-sway control.
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Orlov, Vladislav, Uliana Monakhova, Mikhail Ovchinnikov, and Danil Ivanov. "Fuelless On-Orbit Assembly of a Large Space Truss Structure Using Repulsion of the Service Spacecraft by Robotic Manipulators." Aerospace 11, no. 8 (2024): 635. http://dx.doi.org/10.3390/aerospace11080635.
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A servicing spacecraft motion control approach for the problem of on-orbit truss structure assembly is developed in this paper. It is considered that a cargo container with a rod set and servicing spacecraft are in orbit initially. The assembly procedure is based on spacecraft free-flight motion between the structure’s specified points. The spacecraft is equipped with two robotic manipulators capable of attaching to the structure and holding rods. In addition, the spacecraft can repulse from the structure with a given relative velocity using a manipulator, so the spacecraft and the structure receive impulses. The repulsion velocity vector is calculated in order to reach the structure target point to deliver and install the rod into the truss structure, or to reach the cargo container and take a rod. The problem of searching the repulsion velocity is formulated as an optimization problem with constraints, taking into account the limited value of the repulsion velocity, collision avoidance with structure, restrictions on the angular velocity and translational motion of the structure in the orbital reference frame. This problem is solved numerically with an initial guess vector obtained analytically for simplified motion cases. The application of the proposed control scheme to the assembly of a truss-based antenna is demonstrated. It is shown that the servicing spacecraft is successfully transferred between the structure points by means of manipulator repulsion. Main features and limitations of the assembly problem using a spacecraft with two manipulators are discussed.
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FUKUDA, Toshio, Akito SUZUKI, and Heki SIBATA. "Active suppression control method of fluid vibrations in a container. 2nd Report. Vibration control of the liquid in transferring a container by considering the rotational motion." Transactions of the Japan Society of Mechanical Engineers Series C 56, no. 532 (1990): 3259–66. http://dx.doi.org/10.1299/kikaic.56.3259.
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Hamilton, G., Z. Disharoon, and H. Sanabria. "Revisiting viscosity from macroscopic to nanoscale regimes." Revista Mexicana de Física E 64, no. 2 (2018): 222. http://dx.doi.org/10.31349/revmexfise.64.222.
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The response of a fluid to deformation by shear stress is known as shear viscosity. This concept arises from a macroscopic view and was first introduced by Sir Isaac Newton. Nonetheless, a fluid is a series of moving molecules that are constrained by the shape of the container. Such a view begs the treatment of viscosity from a microscopic or molecular view, a task undertaken by both Einstein and Smoluchowski independently. Here we revisit the concept of viscosity and experimentally verify that the viscosity at a molecular level, which describes the drag force, is the same as the macroscopic shear viscosity; hence, bridging different length- and time-scales. For capturing the shear stress response of a fluid, we use classical rheometry; at a molecular level we use probe diffusion to determine the local viscosity fromthe translational and rotational motions. In these cases, we use Fluorescence Correlation Spectroscopy and Time Resolved Fluorescence, respectively. By increasing the osmolyte (Glucose-D) concentration, we change the viscosity and find that these methods provide a unified view of viscosity, bridging the gap between the macroscopic and nanoscale regimes. Moreover, Glucose’s viscosity follows a scaling factormore commonly associated to solutions of branched polymer because the probe dimensions are comparable to the dimensions of the osmolyte that exerts the drag.
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Kozlov, N. V., E. A. Mosheva, and A. V. Shmyrov. "Visualization of hydrodynamic and physico-chemical processes in rotating and vibrating containers." Journal of Physics: Conference Series 2127, no. 1 (2021): 012004. http://dx.doi.org/10.1088/1742-6596/2127/1/012004.
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Abstract Variable inertial fields are an efficient way to control the behaviour of hydrodynamic systems. Forces of inertia can be used, for example, to stabilize or destabilize systems with an interface or density gradient, to mix multiphase or non-isothermal fluids. The implementation of this approach means that liquids fill the periodically moving containers. In this paper, the situations are considered when the containers perform either rotation or translational vibrations. Methods for measuring the density and velocity fields of convective flows in reacting hydrodynamic systems are described. Interferometry is used to visualize the density distribution. Particle image velocimetry (PIV) is used to study the structure and velocity of the flows. Optical instruments are installed stationary in the laboratory system. For video recording, a camera shutter is synchronized with the motion of a container, and thus the images are captured in a fixed phase of oscillations or rotation. Constructions of the containers make it possible to illuminate the working volume through transparent walls at different angles or in different planes. They also provide a compensation for the centrifugal pressure and allow interference cells to be used in overload conditions. The successful application of the methods in experimental studies of chemo-hydrodynamic processes is demonstrated.
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Liu, Xiaoqin, Xiang Li, Qi Shi, Chuanpei Xu, and Yanmei Tang. "UAV attitude estimation based on MARG and optical flow sensors using gated recurrent unit." International Journal of Distributed Sensor Networks 17, no. 4 (2021): 155014772110098. http://dx.doi.org/10.1177/15501477211009814.
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Three-dimensional attitude estimation for unmanned aerial vehicles is usually based on the combination of magnetometer, accelerometer, and gyroscope (MARG). But MARG sensor can be easily affected by various disturbances, for example, vibration, external magnetic interference, and gyro drift. Optical flow sensor has the ability to extract motion information from image sequence, and thus, it is potential to augment three-dimensional attitude estimation for unmanned aerial vehicles. But the major problem is that the optical flow can be caused by both translational and rotational movements, which are difficult to be distinguished from each other. To solve the above problems, this article uses a gated recurrent unit neural network to implement data fusion for MARG and optical flow sensors, so as to enhance the accuracy of three-dimensional attitude estimation for unmanned aerial vehicles. The proposed algorithm can effectively make use of the attitude information contained in the optical flow measurements and can also achieve multi-sensor fusion for attitude estimation without explicit mathematical model. Compared with the commonly used extended Kalman filter algorithm for attitude estimation, the proposed algorithm shows higher accuracy in the flight test of quad-rotor unmanned aerial vehicles.
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Pan, Kai, and Dengqing Cao. "Absolute nodal coordinate finite element approach to the two-dimensional liquid sloshing problems." Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 234, no. 2 (2020): 322–46. http://dx.doi.org/10.1177/1464419320907785.
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Two-dimensional large-amplitude liquid sloshing in the rectangular rigid container is numerically simulated through absolute nodal coordinate finite element method, which can describe the large deformation of continuum by using a small number of elements. The incompressible constraint of Newtonian fluid is imposed by the penalty function method. Furthermore, the motion of rigid container is described by absolute nodal coordinate reference node and the liquid kinetic equations are derived in the total Lagrangian formulation, which can easily be combined with the solid nonlinear finite element and the multi-body system algorithms. The free sliding and non-penetrating boundary constraint equations for rectangular tank are derived. To ensure the stability and the conservation of the solution in long time simulations, the system dynamic equations are solved by Bathe integral scheme. Three numerical examples are used to verify the effectiveness of the proposed method, including the free spreading of a square liquid column and the large amplitude sloshing of liquid under rotational and horizontal excitations. A good consistency is obtained by comparing the calculated results with experimental and other numerical results reported in the literature.
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HIRSCH, J. E. "KINETIC ENERGY DRIVEN SUPERCONDUCTIVITY AND SUPERFLUIDITY." Modern Physics Letters B 25, no. 29 (2011): 2219–37. http://dx.doi.org/10.1142/s0217984911027613.
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The theory of hole superconductivity proposes that superconductivity is driven by lowering of quantum kinetic energy and is associated with expansion of electronic orbits and expulsion of negative charge from the interior to the surface of superconductors and beyond. This physics provides a dynamical explanation of the Meissner effect. Here we propose that similar physics takes place in superfluid helium 4. Experimental manifestations of this physics in 4 He are the negative thermal expansion of 4 He below the λ point and the "Onnes effect", the fact that superfluid helium will creep up the walls of the container and escape to the exterior. The Onnes effect and the Meissner effect are proposed to originate in macroscopic zero point rotational motion of the superfluids. It is proposed that this physics indicates a fundamental inadequacy of conventional quantum mechanics.
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Gilski, Miroslaw, Piotr Bernatowicz, Arkadiusz Sakowicz, et al. "C60 in a peptidic cage: a case of symmetry mismatch studied by crystallography and solid-state NMR." Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials 76, no. 5 (2020): 815–24. http://dx.doi.org/10.1107/s2052520620009944.
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A supramolecular complex, formed by encapsulation of C60 fullerene in a molecular container built from two resorcin[4]arene rims zipped together by peptidic arms hydrogen bonded into a cylindrical β-sheet, was studied by X-ray crystallography, solid-state and solution NMR, EPR spectroscopy and differential scanning calorimetry (DSC). The crystal structure, determined at 100 K, reveals that the complex occupies 422 site symmetry, which is compatible with the molecular symmetry of the container but not of the fullerene molecule, which has only 222 symmetry. The additional crystallographic symmetry leads to a complicated but discrete disorder, which could be resolved and modelled using advanced features of the existing refinement software. Solid-state NMR measurements at 184–333 K indicate that the thermal motion of C60 in this temperature range is fast but has different activation energies at different temperatures, which was attributed to a phase transition, which was confirmed by DSC. Intriguingly, the activation energy for reorientations of C60 in the solid state is very similar for the free and encaged molecules. Also, the rotational diffusion coefficients seem to be very similar or even slightly higher for the encaged fullerene compared to the free molecule. We also found that chemical shift anisotropy (CSA) is not the main relaxation mechanism for the 13C spins of C60 in the studied complex.
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Raynovskyy, I. A. "Steady-state resonant sloshing in upright cylindrical tank due to elliptical forcing." Bulletin of Taras Shevchenko National University of Kyiv. Series: Physics and Mathematics, no. 1 (2019): 166–69. http://dx.doi.org/10.17721/1812-5409.2019/1.38.
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The nonlinear Narimanov-Moiseev multimodal equations are used to study the swirling-type resonant sloshing in a circular base container occurring due to an orbital (rotary) tank motion in the horizontal plane with the forcing frequency close to the lowest natural sloshing frequency. These equations are equipped with linear damping terms associated with the logarithmic decrements of the natural sloshing modes. The surface tension is neglected. An asymptotic steady-state solution is constructed and the response amplitude curves are analyzed to prove their hard-spring type behavior for the finite liquid depth (the mean liquid depth-to-the-radius ratio h>1). For the orbital forcing only swirling occurs. This behavior type is supported by the existing experimental data. Phase lags, which are piecewise functions along the continuous amplitude response curves in the undamped case, become of the non-constant character when the damping matters. The wave elevations at the vertical wall are satisfactory predicted except for a frequency range where the model test observations reported wave breaking and/or mean rotational flows.
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Pérez-Gudiño, José Luis, Marco Antonio Gómez-Guzmán, Chayanne García-Valdez, Roberto Valentín Carrillo-Serrano, Gerardo Israel Pérez-Soto, and Juvenal Rodríguez-Reséndiz. "The Low-Cost Mechanism of a Defined Path Guide Slot-Based Passive Solar Tracker Intended for Developing Countries." Technologies 12, no. 12 (2024): 250. https://doi.org/10.3390/technologies12120250.
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Solar trackers represent a significant advancement in enhancing the efficiency of solar energy collection. This study describes the development and implementation of a passive solar tracker featuring a single horizontal axis of rotation and an innovative guide slot mechanism. The tracker is designed to be used with solar radiation-capturing devices. The guide slot mechanism is specifically engineered for a designated date, location, and period to follow the solar trajectory accurately. A contact follower moves along the guide slot, which drives a tracker disk to rotate by the solar trajectory. The mechanism is activated by the movement of a liquid container attached to a spring, thereby storing potential energy. The container releases the liquid through a mechanical valve that regulates the container’s movement, while the guide slot mechanism converts this movement into controlled rotational motion, which is transferred to a mobile structure mounting the solar panel. Notably, the majority of materials utilized in this construction are recycled. Furthermore, the solar tracker proposed in this work is designed to be operable by individuals with limited prior knowledge on the topic, emphasizing the primary contribution of this study: its potential to revolutionize energy collection in developing countries and marginalized urban areas. No similar systems are found upon comparison with existing models in the literature. Experiments conducted with a static solar panel and the same panel integrated into the passive solar tracker revealed a 30.87% improvement in energy collection efficiency over static solar panels.
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Kozhushko, Andrii, Yevhen Pelypenko, Serhii Kravchenko, and Vitalii Danylenko. "Improving the procedure for modeling low-frequency oscillations of the free surface liquid in a tractor tank." Eastern-European Journal of Enterprise Technologies 2, no. 7 (122) (2023): 61–68. http://dx.doi.org/10.15587/1729-4061.2023.277254.
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This paper considers the influence of hydrodynamic processes in the movement of the free surface of liquid in partially filled tractor tanks. Splashing liquid in partially filled containers is a significant problem in the study of functional stability of movement in the marine, aerospace, rail, and automotive industries. After all, it affects productivity and traffic safety. The same effect was observed when performing transportation work while delivering liquid cargoes in the agricultural sector. That was due to increasing the transportation speeds of wheeled tractors. In the procedure, using the Rayleigh theory of surface waves, a linearized problem of motion of the free surface of a liquid is obtained. Based on Helmholtz's theorem, the components of scalar and Laplace field vector potentials of fluid velocity vector are separated. The potential problem for translational motion of fluid, in which vortex component of the field is absent, is considered. Instead of the fluid velocity potential, a scalar fluid displacement potential in Rayleigh surface waves was introduced. Comparing the results of calculating fluid splashing with the work of other scientists, a high convergence of natural frequencies of partial oscillators in 3D space was found. This is noticeable in the last quarter of the filling of the tank, in which significant displacements of the deep liquid occur. A feature of the results is the introduction, instead of the real shape of the container, an equivalent form of a parallelepiped, the final shape of which depends on the level of fullness. The frequency properties of movement of the free surface of liquid based on the standard size of tanks used in agriculture are separated. The proposed improved methodology could be used to increase stability, controllability, and smoothness when operating tanks with a wheeled tractor.
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Andrii, Kozhushko, Pelypenko Yevhen, Kravchenko Serhii, and Danylenko Vitalii. "Improving the procedure for modeling low-frequency oscillations of the free surface liquid in a tractor tank." Eastern-European Journal of Enterprise Technologies 2, no. 7(122) (2023): 61–68. https://doi.org/10.15587/1729-4061.2023.277254.
Full textAbstract:
This paper considers the influence of hydrodynamic processes in the movement of the free surface of liquid in partially filled tractor tanks. Splashing liquid in partially filled containers is a significant problem in the study of functional stability of movement in the marine, aerospace, rail, and automotive industries. After all, it affects productivity and traffic safety. The same effect was observed when performing transportation work while delivering liquid cargoes in the agricultural sector. That was due to increasing the transportation speeds of wheeled tractors. In the procedure, using the Rayleigh theory of surface waves, a linearized problem of motion of the free surface of a liquid is obtained. Based on Helmholtz's theorem, the components of scalar and Laplace field vector potentials of fluid velocity vector are separated. The potential problem for translational motion of fluid, in which vortex component of the field is absent, is considered. Instead of the fluid velocity potential, a scalar fluid displacement potential in Rayleigh surface waves was introduced. Comparing the results of calculating fluid splashing with the work of other scientists, a high convergence of natural frequencies of partial oscillators in 3D space was found. This is noticeable in the last quarter of the filling of the tank, in which significant displacements of the deep liquid occur. A feature of the results is the introduction, instead of the real shape of the container, an equivalent form of a parallelepiped, the final shape of which depends on the level of fullness. The frequency properties of movement of the free surface of liquid based on the standard size of tanks used in agriculture are separated. The proposed improved methodology could be used to increase stability, controllability, and smoothness when operating tanks with a wheeled tractor.
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Topilnytskyy, Volodymyr, Yaroslav Kusyi, and Dariya Rebot. "RESEARCH OF VIBRATION MACHINES DYNAMICS FOR PRODUCT SURFACES PROCESSING BY MATHEMATICAL MODELING." Vibrations in engineering and technology, no. 1(96) (August 27, 2020): 35–43. http://dx.doi.org/10.37128/2306-8744-2020-1-4.
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The article describes the methodology for the study of the dynamics of vibrating machines for surface processing of products by mathematical modeling, which is presented in four main stages. The first stage: analysis of classes of vibrating machines for surface treatment of products, choice of basic for solving the technological problem, project of a unified calculation scheme of the machine. The second stage: development of a nonlinear mathematical model for describing the dynamics of the vibration machine working body and its filling, development of elements of automated calculations of the machine. The third stage: the study of the influence of the parameters of the vibrating machine, product sets and tools (with their various combinations) on the factors of the intensity of products surface processing. The fourth stage: recommendations for choosing vibrating machine parameters and machining bodies that will maximize the processing performance of products with the selected intensity criterion. A mathematical model for describing the motion of a vibrating machine for surface treatment of articles by a set of unrelated bodies of small size is created. It has two unbalance units that generate oscillations of its working body and a spring suspension-mounting of the working chamber (container). The model is parametric and nonlinear, incorporating key dynamic, kinematic and geometric parameters of the vibrating machine in symbolic format. It is constructed by: descriptions of the plane-parallel movement of the mechanical system, the rotational motion of the material point and the body; second-order Lagrange equation; asymptotic (approximate) methods of nonlinear mechanics. With the help of the model it is possible: to describe the oscillatory movement of the working chamber (container) of the vibrating machine; to study the influence of the machine parameters on the efficiency of performance of the set technological task, the conditions of occurrence of non-stationary modes of operation of the vibrating machine and the ways of their regulation.
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Soechting, J. F., and M. Flanders. "Organization of sequential typing movements." Journal of Neurophysiology 67, no. 5 (1992): 1275–90. http://dx.doi.org/10.1152/jn.1992.67.5.1275.
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1. Experienced touch typists were asked to type words that contained only one or two letters typed by one of the two hands. When a word contained a pair of letters typed by one hand, the letters could be consecutive, or there could be one, two, or three intervening letters typed with the other hand. 2. We studied cases in which pairs of letters were either identical, different but typed with the same finger, or typed with two different fingers on the same hand. 3. Translational and rotational motion of the fingers and wrist was computed optoelectronically from the location of reflective markers on the hands. Finger and wrist motion recorded when subjects typed pairs of letters was compared with the motion recorded when the subject typed either letter in isolation. 4. When the subject typed the same letter consecutively, or separated by intervening letters, the second keystroke began only after the first key had been pressed. The same result was obtained when the second letter was not identical but was typed with the same finger. Up to the time of the first keypress, the initial keystroke kinematics were identical to those for that letter typed in isolation. 5. When the second letter in a pair was typed with the use of a different finger, the initial focal movement (wrist and finger striking the key) was unaffected up to the time of initial keypress. However, the second finger could begin to move toward the second key shortly before the initial keypress, and therefore the corollary movements normally involved in the initial keystroke were affected. 6. These results indicate that typing movements are executed primarily in a serial fashion, letter by letter. There can be some overlap between consecutive keystrokes only if they are executed with different fingers. 7. Words in which two letters typed with one hand were separated by three letters typed with the other hand provided subjects the opportunity to initiate the second keystroke at a range of times after the first keypress. 8. When the second letter differed from the first, subjects always returned to the home position after the first keypress and initiated the second keystroke with a normal latency. However, when the second letter was the same as the first letter, subjects sometimes suppressed the return to the home position after the first keystroke and maintained their finger poised over the key. 9. Thus keystrokes of one hand are best described as being executed sequentially. However, the findings presented here also indicate that movement planning encompasses strings of letters.
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ISHIKAWA, TAKUJI, and T. J. PEDLEY. "Diffusion of swimming model micro-organisms in a semi-dilute suspension." Journal of Fluid Mechanics 588 (September 24, 2007): 437–62. http://dx.doi.org/10.1017/s0022112007007847.
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The diffusive behaviour of swimming micro-organisms should be clarified in order to obtain a better continuum model for cell suspensions. In this paper, a swimming micro-organism is modelled as a squirming sphere with prescribed tangential surface velocity, in which the centre of mass of the sphere may be displaced from the geometric centre (bottom-heaviness). Effects of inertia and Brownian motion are neglected, because real micro-organisms swim at very low Reynolds numbers but are too large for Brownian effects to be important. The three-dimensional movement of 64 or 27 identical squirmers in a fluid otherwise at rest, contained in a cube with periodic boundary conditions, is dynamically computed, for random initial positions and orientations. The computation utilizes a database of pairwise interactions that has been constructed by the boundary element method. In the case of (non-bottom-heavy) squirmers, both the translational and the orientational spreading of squirmers is correctly described as a diffusive process over a sufficiently long time scale, even though all the movements of the squirmers were deterministically calculated. Scaling of the results on the assumption that the squirmer trajectories are unbiased random walks is shown to capture some but not all of the main features of the results. In the case of (bottom-heavy) squirmers, the diffusive behaviour in squirmers' orientations can be described by a biased random walk model, but only when the effect of hydrodynamic interaction dominates that of the bottom-heaviness. The spreading of bottom-heavy squirmers in the horizontal directions show diffusive behaviour, and that in the vertical direction also does when the average upward velocity is subtracted. The rotational diffusivity in this case, at a volume fractionc=0.1, is shown to be at least as large as that previously measured in very dilute populations of swimming algal cells (Chlamydomonas nivalis).
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Liu, Yong, Renxiang Bu, and Xiaori Gao. "Ship Trajectory Tracking Control System Design Based on Sliding Mode Control Algorithm." Polish Maritime Research 25, no. 3 (2018): 26–34. http://dx.doi.org/10.2478/pomr-2018-0093.
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Abstract The paper reports the design and tests of the planar autopilot navigation system in the three-degree-of-freedom (3-DOF) plane (surge, sway and yaw) for a ship. The aim of the tests was to check the improved maneuverability of the ship in open waters using the improved nonlinear control algorithm, developed based on the sliding mode control theory for the ship-trajectory tracking problem of under-actuated ships with static constraints, actuator saturation, and parametric uncertainties. With the integration of the simple increment feedback control law, the dynamic control strategy was developed to fulfill the under-actuated tracking and stabilization objectives. In addition, the LOS (line of sight) guidance system was applied to control the motion path, whereas the sliding mode controller was used to emulate the rudder angle and propeller rotational speed control. Firstly, simulation tests were performed to verify the validity of the basic model and the tracking control algorithm. Subsequently, full scale maneuverability tests were done with a novel container ship, equipped with trajectory tracking control and sliding mode controller algorithm, to check the dynamic stability performance of the ship. The results of the theoretical and numerical simulation on a training ship verify the invariability and excellent robustness of the proposed controller, which: effectively eliminates system chattering, solves the problem of lateral drift of the ship, and maintains the following of the trajectory while simultaneously achieving global stability and robustness.
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Hodge, S. J., P. Perfect, G. D. Padfield, and M. D. White. "Optimising the yaw motion cues available from a short stroke hexapod motion platform." Aeronautical Journal 119, no. 1211 (2015): 1–21. http://dx.doi.org/10.1017/s0001924000010228.
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AbstractThis paper presents findings from research conducted at the University of Liverpool aimed at optimising the motion cues available from a short-stroke hexapod motion platform. Piloted simulation experiments were conducted to gather both objective and subjective measures of pilot performance and motion fidelity for a typical helicopter low-speed yaw axis capture task. These measures included subjective ratings taken for the first time using a new motion fidelity rating scale. During the experiment four baseline configurations were presented to the pilot; – No motion, Rotational-only motion, Translational-only motion and Rotational + Translational motion, and within these baseline configurations various values of motion filter gains were examined. The key findings from the experiment show that the most acceptable motion fidelity was obtained when congruent cues were presented in both the rotational and translational axes. A possible explanation for this result is postulated to lie within the relative motion perception thresholds of the human semicircular canals. These results contrast with previous research which suggested that yaw axis motion cues were of less importance than translational motion cues.
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Theeyancheri, Ligesh, Subhasish Chaki, Nairhita Samanta, Rohit Goswami, Raghunath Chelakkot, and Rajarshi Chakrabarti. "Translational and rotational dynamics of a self-propelled Janus probe in crowded environments." Soft Matter 16, no. 36 (2020): 8482–91. http://dx.doi.org/10.1039/d0sm00339e.
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The ratio between translational and rotational diffusivities of a self-propelled Janus probe points that activity can decouple the translational and rotational motion at an intermediate volume fraction of the passive crowders.
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Moncrieffe, Martin C., Steven Eaton, Z̆eljko Bajzer, et al. "Rotational and Translational Motion of Troponin C." Journal of Biological Chemistry 274, no. 25 (1999): 17464–70. http://dx.doi.org/10.1074/jbc.274.25.17464.
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Frech, T., and H. G. Hertz. "Rotational, Internal Rotational, and Translational Motion of Liquid i-Propanol." Berichte der Bunsengesellschaft für physikalische Chemie 89, no. 9 (1985): 948–58. http://dx.doi.org/10.1002/bbpc.19850890906.
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Nigbor, Robert L. "Six-degree-of-freedom ground-motion measurement." Bulletin of the Seismological Society of America 84, no. 5 (1994): 1665–69. http://dx.doi.org/10.1785/bssa0840051665.
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Abstract True six-degree-of-freedom (6DOF) measurement of free-field strong ground motion has been accomplished using a prototype 6DOF accelerograph system. This system consists of a traditional triaxial translational accelerometer, three new rotational velocity sensors, and a digital data logger. Rotational and translational ground motions at a single free-field location were measured successfully during the recent NPE event, a very large (1 kton) chemical explosion. Peak vertical acceleration at the near-field measurement site exceeded 1g for this event; the peak measured rotational velocity was 2.2°/sec. Earthquake strong-ground-motion measurements are currently in progress.
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Bae, Suhong, Junhyoung Kwon, Jongyul Kim, and Gunhee Jang. "Optimal Motion Control of a Capsule Endoscope in the Stomach Utilizing a Magnetic Navigation System with Dual Permanent Magnets." Micromachines 15, no. 8 (2024): 1032. http://dx.doi.org/10.3390/mi15081032.
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We propose a method to control the motion of a capsule endoscope (CE) in the stomach utilizing either a single external permanent magnet (EPM) or dual EPMs to extend the examination of the upper gastrointestinal tract. When utilizing the conventional magnetic navigational system (MNS) with a single EPM to generate tilting and rotational motions of the CE, undesired translational motion of the CE may prevent accurate examination. We analyzed the motion of the CE by calculating the magnetic torque and magnetic force applied to the CE using the point-dipole approximation model. Using the proposed model, we propose a method to determine the optimal position and orientation of the EPM to generate tilting and rotational motions without undesired translational motion of the CE. Furthermore, we optimized the weight of dual EPMs to develop a lightweight MNS. We prototyped the proposed MNS and experimentally verified that the developed MNS can generate tilting and rotational motions of the CE without any translational motion.
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Zhu, Chi, Yasumichi Aiyama, Tamio Arai, and Atsuo Kawamura. "Characteristics of Frictional Sliding Motion in Releasing Manipulation." Journal of Robotics and Mechatronics 18, no. 1 (2006): 26–35. http://dx.doi.org/10.20965/jrm.2006.p0026.
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Focusing on freely frictional sliding motion and based on mathematical analysis and physical concepts, it is clarified that the translational and rotational motions stop simultaneously, and the direction of final motion depends on the final configuration and geometric properties of an object but is independent of initial velocity. One extreme case of initially translation-dominant motion is intensively investigated with simplified approach. A series of important properties and motion monotonicity of sliding motion are obtained. Based on the above results, an inverse problem to determine the necessary initial translational and rotational velocity becomes very easy and straightforward.
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JOHNSON, AARON P., W. JON P. BARNES, and MARTIN W. S. MACAULEY. "Local mechanisms for the separation of optic flow-field components in the land crab, Cardisoma guanhumi: A role for motion parallax?" Visual Neuroscience 21, no. 6 (2004): 905–11. http://dx.doi.org/10.1017/s0952523804216108.
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Although a number of global mechanisms have been proposed over the years that explain how crabs might separate the rotational and translational components of their optic flow field, there has been no evidence to date that local mechanisms such as motion parallax are used in this separation. We describe here a study that takes advantage of a recently developed suite of computer-generated visual stimuli that creates a three-dimensional world surrounding the crab in which we can simulate translational and rotational optic flow. We show that, while motion parallax is not the only mechanism used in flow-field separation, it does play a role in the recognition of translational optic flow fields in that, under conditions of low overall light intensity and low contrast ratio when crabs find the distinction between rotation and translation harder, smaller eye movements occur in response to translation when motion parallax cues are present than when they are absent. Thus, motion parallax is one of many cues that crabs use to separate rotational and translational optic flow by showing compensatory eye movements to only the former.
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Yamashita, Norio, and Akio Yamamoto. "Three-DOF Electrostatic Induction Actuator Providing Translational and Rotational Surface-Drive Motion." International Journal of Automation Technology 10, no. 4 (2016): 525–32. http://dx.doi.org/10.20965/ijat.2016.p0525.
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This paper describes the driving characteristics of a three degree-of-freedom (three-DOF) electrostatic induction actuator, which can demonstrate surface-drive characteristics with translational and rotational motions. It consists of a sheet-type slider without electrodes and a planar stator with an array of three-phase driving electrodes. The electrodes with different orientations are aligned in a regular manner to construct a four-by-four checkerboard pattern. Controlling applied voltage patterns can generate translational or rotational patterns of electrostatic fields, which drive the slider. The performance of the three-DOF actuator with regards to translational and rotational motion was investigated.
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Nawrocki, Dariusz, Maciej Mendecki, and Leslaw Teper. "The effects of component rotation on H/V spectra: a comparison of rotational and translational data." Geology, Geophysics and Environment 50, no. 2 (2024): 145–54. https://doi.org/10.7494/geol.2024.50.2.145.
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The presented investigation focused on site effect estimations, specifically resonance frequency and amplification. These estimations were carried out for both rotational and translational signals, using waveforms from mining-induced seismic events. Site effect parameters were calculated using the horizontal-to-vertical spectral ratio (HVSR) technique, which is commonly applied to translational records by comparing the spectral ratio between horizontal and vertical components. In this study, we also applied the horizontal-to-vertical (H/V) ratio to rotational records. However, due to the different orientations of motion propagation, we introduced the spectral H/V ratio for rotational motion as the torsion-to-rocking spectral ratio (TRSR). Furthermore, we analyzedthese signals according to two approaches. First, we estimated the site effect parameters for directly registered signals, and secondly, we considered rotated components by varying the angle from 0° to 180° in 5-degree increments. Generally, the H/V curves indicated two peaks for translational motions and four peaks for rotational motions. The averaged H/V spectra and spectra obtained for different angles of component rotation showed insignificant fluctuation in amplification values for both rotational and translational motions. However, when comparing each component’s spectrum for all angles, we observed changes in the site effect parameter values for both motion types. Radar plots depicting amplification values versus rotation angles for separated components revealed characteristic fluctuations, suggesting local anisotropy. Moreover, when comparing the radar plots between rotational and translational results, it was evident that rotational resonance frequencies shifted to higher frequency values, potentially indicating shallower geological layers as their source.
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Li, Zhenhua, and Mirko van der Baan. "Tutorial on rotational seismology and its applications in exploration geophysics." GEOPHYSICS 82, no. 5 (2017): W17—W30. http://dx.doi.org/10.1190/geo2016-0497.1.
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Traditionally, seismological interpretations are based on the measurement of only translational motions, such as particle displacement, velocity, and/or acceleration, possibly combined with pressure changes; yet theory indicates that rotational motions should also be observed for a complete description of all ground motions. The recent and ongoing development of rotational sensors renders a full analysis of the translational and rotational ground motion possible. We have developed the basic mathematical theory related to rotational motion. And we also evaluated several instruments used to directly measure the rotational ground motion, which may be applicable for exploration geophysics. Finally, we made several applications of rotational motion in exploration geophysics, namely, (1) P- and S-wavefield separation, (2) wavefield reconstruction, (3) ground-roll removal, (4) microseismic event localization and reflection seismic migration by wavefield extrapolation, and (5) moment tensor inversion. The cited research shows that in particular, the information on the spatial gradient of the wavefield obtained by rotational sensors is beneficial for many purposes. This tutorial is meant to (1) enhance familiarity with the concept of rotational seismology, (2) lead to additional applications, and (3) fast track the continued development of rotational sensors for global and exploration geophysical use.
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KIMURA, YUSUKE, KOSUKE SUZUKI, and TAKAJI INAMURO. "FLIGHT SIMULATIONS OF A TWO-DIMENSIONAL FLAPPING WING BY THE IB-LBM." International Journal of Modern Physics C 25, no. 01 (2013): 1340020. http://dx.doi.org/10.1142/s0129183113400202.
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The stability of flight by flapping wings is investigated by using the immersed boundary-lattice Boltzmann method (IB-LBM). First, the rotational motion with an initial small disturbance is computed, and it is found that the rotational motion is unstable for high Reynolds numbers. Second, we show simple ways to control the rotational and translational motion by bending or flapping the tip of the wing.
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Espinosa-Rodríguez, José, Pedro Díaz-Leyva, and Rodrigo Sánchez. "Rotational and translational dynamics and rheology in a granular system." Journal of Statistical Mechanics: Theory and Experiment 2024, no. 6 (2024): 063206. http://dx.doi.org/10.1088/1742-5468/ad4e27.
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Abstract The present work examines the translational and rotational dynamics, as well as their implications for system rheology, of an experimental granular system at an agitated air/water interface. A decoupling of rotational and translational dynamics is found. The translational dynamics is well-described by a modified Voigt model compatible to that obtained for prior simulational work, whereas the rotational motion alternates between two distinct states. The latter behaviour is accounted for in terms of collective effects at the edges.
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Rong, Chao, Dingfan Zhang, Yuwen Cao, and Zhengbin Li. "Analyze the Difference Between Rotational and Translational Motions Produced by High-speed Train." Journal of Physics: Conference Series 2651, no. 1 (2023): 012141. http://dx.doi.org/10.1088/1742-6596/2651/1/012141.
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Abstract The development of fiber optic gyroscope technology makes it possible to directly measure the rotational ground-motion. The joint observation of the three-component rotational seismometer and the traditional three-component translational seismometer is a trend of future. In this paper, the translational and rotational signals generated during the high-speed trainway are studied, and the three-component translational and rotational seismometers are fixed together to realize the joint recording of the high-speed trainway signal. Comparing the translational and rotational three-component data, we find that only one component waveforms and the spectrum have certain consistency. However, the difference between them indicates that the rotation and translation signals generated by the shallow surface wave signal have different frequency bands.
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Geschwindner, Christopher, Maren Werner, Laurent André, et al. "High-Resolution Two-Phase Velocimetry Of Aspherical Particles Using Wavelet-Based Optical Flow Velocimetry (WOFV) Benchmarked With Fully Resolved Direct Numerical Simulations." Proceedings of the International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics 21 (July 8, 2024): 1–21. http://dx.doi.org/10.55037/lxlaser.21st.101.
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Several techniques exist to measure the carrier and dispersed phases in multi-phase flows. Particle image velocimetry (PIV) analyzes the carrier phase by cross-correlating particle images, but its resolution is limited by the size of the interrogation window, making it difficult to resolve fine-scale turbulent structures. Particle tracking algorithms capture translational motion of dispersed particles well, but struggle with rotational motion, especially for irregular and aspherical particles. Currently, there is no method that universally measures both the carrier phase velocity field and the translational and rotational motions of dispersed particles. This study evaluates wavelet-based optical flow velocimetry (wOFV) for motion estimation in multi-phase flows, focusing on dispersed ellipsoidal particles and their surrounding turbulent carrier flow using synthetic image data. The research proceeds in two phases: first, the rigid motion of ellipses, including translational and rotational components, is analyzed using wOFV-generated dense motion fields. The results highlight the critical role of the regularization weighting parameter λ. Higher λ values improve translational motion estimation, while an optimal λ avoids under-regularization and non-physical structures in rotational motion. wOFV maintains accuracy in combined motion scenarios with optimal λ values. In the second phase, wOFV captures the turbulent carrier flow around an aspherical particle, benchmarked against DNS data and compared to PIV. wOFV outperforms PIV in resolving finer structures near the particle surface and in accurately representing the wake region. Error analyses confirm wOFV’s superior performance, with optimal results within a specific λ range. In conclusion, wOFV is a highly effective tool for the analysis of multi-phase flow dynamics, providing greater resolution and accuracy than PIV, especially in complex scenarios involving aspherical particles.
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Minglibayev, M. Zh, and S. B. Bizhanova. "TRANSLATIONAL-ROTATIONAL MOTION OF A NONSTATIONARY AXISYMMETRIC BODY." PHYSICO-MATHEMATICAL SERIES 2, no. 336 (2021): 131–37. http://dx.doi.org/10.32014/2021.2518-1726.32.
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A nonstationary two-body problem is considered such that one of the bodies has a spherically symmetric density distribution and is central, while the other one is a satellite with axisymmetric dynamical structure, shape, and variable oblateness. Newton’s interaction force is characterized by an approximate expression of the force function up to the second harmonic. The masses of the central body and the satellite vary isotropically at different rates and do not occur reactive forces and additional rotational moments. The nonstationary axisymmetric body have an equatorial plane of symmetry. Thus, it has three mutually perpendicular planes of symmetry. The axes of its intrinsic coordinate system coincide with the principal axes of inertia and they are directed along the intersection lines of these three mutually perpendicular planes. This position remains unchangeable during the evolution. Equations of motion of the satellite in a relative system of coordinates are considered. The translational- rotational motion of the nonstationary axisymmetric body in the gravitational field of the nonstationary ball is studied by perturbation theory methods. The equations of secular perturbations reduces to the fourth order system with one first integral. This first integral is considered and three-dimensional graphs of this first integral are plotted using the Wolfram Mathematica system.
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Minglibayev, M. Zh, and A. A. Myrzabayeva. "TRANSLATIONAL-ROTATIONAL MOTION OF TWO NON-STATIONARY BODIES." SERIES PHYSICO-MATHEMATICAL 3, no. 337 (2021): 106–12. http://dx.doi.org/10.32014/2021.2518-1726.52.
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Hwang, Byung-Woo, and Alexander C. Schütz. "Idiosyncratic preferences in translational and rotational motion transparency." Journal of Vision 21, no. 9 (2021): 2044. http://dx.doi.org/10.1167/jov.21.9.2044.
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Nagel, Eike, Matthias Sluber, Otto M. Hess, and Peter Boesiger. "Translational and rotational motion of the right ventricle." Journal of the American College of Cardiology 27, no. 2 (1996): 366. http://dx.doi.org/10.1016/s0735-1097(96)82385-0.
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Porter, Katharine B., Gideon P. Caplovitz, Peter J. Kohler, Christina M. Ackerman, and Peter U. Tse. "Rotational and translational motion interact independently with form." Vision Research 51, no. 23-24 (2011): 2478–87. http://dx.doi.org/10.1016/j.visres.2011.10.005.
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