LIKE TRAJECTORIES OF THE BODY MOTION IN THE MEDIUM, THE RESISTANCE OF WHICH IS PROPORTIONAL TO THE SQUARE OF RELATIVE VELOCITY

2020 ◽  
pp. 71-76
Author(s):  
V.A. Chernovolov ◽  
◽  
L.V. Kravchenko ◽  
S.A. Sherstov
Keyword(s):  
Initial Velocity ◽  
Relative Velocity ◽  
The Body ◽  
Body Motion ◽  
Initial Angle ◽  
Air Resistance ◽  
Simultaneous Change

The force of gravity and the force of air resistance affect a particle thrown at an angle to the horizon with an initial velocity. In the calculation of wind protection and distribution devices, it becomes necessary to reduce the differences in trajectories when changing the type of fertilizer. There are two possibilities for simple adjustments. First, you can try to increase the throwing speed of fertilizers with a high windage factor. Secondly, the initial throwing angle can be adjusted. However, it is not possible to achieve alignment of the trajectories by adjusting the throwing angle. The smallest difference in trajectories was obtained by combining the simultaneous change in the initial angle and throwing speed. By simultaneously adjusting the initial angle and initial throwing speed, it is possible to almost match the trajectories of particles with different wind ratios, which is useful when working with a distributor

LIKE TRAJECTORIES OF THE BODY MOTION IN THE MEDIUM, THE RESISTANCE OF WHICH IS PROPORTIONAL TO THE SQUARE OF RELATIVE VELOCITY

2020 ◽  
pp. 77-83
Author(s):  
A.Y. Peretyatko ◽  
Keyword(s):  
Relative Velocity ◽  
The Body ◽  
Body Motion ◽  
Huge Number ◽  
History Of ◽  
Number Of Publications

For the pre-revolutionary Don historiography, complaints about the lack of a full-fledged generalizing work of the history of the Cossacks were extremely characteristic. As shown in the article, a similar situation is observed in our time: the article has again become the main genre of Cossack historiography, and the understanding of a huge number of publications on the history of various Cossack troops is extremely difficult. The author proves that in these conditions, works that claim to generalize become especially important, but it is extremely difficult to summarize all the facts, developments and research concepts on any broad topic of Cossack history. In his opinion, the search for other methods of scientific generalization and perception by historians of the developments of their colleagues looks promising. One of these ways he sees the organization of round tables on specifically Cossack topics, especially dedicated to new discoveries.

Chaos in body–vortex interactions

2010 ◽  
Vol 466 (2119) ◽  
pp. 1871-1891 ◽  
Author(s):  
Johan Roenby ◽  
Hassan Aref
Keyword(s):  
Body Shape ◽  
Mass Density ◽  
Relative Equilibrium ◽  
Large Body ◽  
Point Vortex ◽  
Cylindrical Body ◽  
The Body ◽  
Body Motion ◽  
Single Vortex ◽  
Vortex Interactions

The model of body–vortex interactions, where the fluid flow is planar, ideal and unbounded, and the vortex is a point vortex, is studied. The body may have a constant circulation around it. The governing equations for the general case of a freely moving body of arbitrary shape and mass density and an arbitrary number of point vortices are presented. The case of a body and a single vortex is then investigated numerically in detail. In this paper, the body is a homogeneous, elliptical cylinder. For large body–vortex separations, the system behaves much like a vortex pair regardless of body shape. The case of a circle is integrable. As the body is made slightly elliptic, a chaotic region grows from an unstable relative equilibrium of the circle-vortex case. The case of a cylindrical body of any shape moving in fluid otherwise at rest is also integrable. A second transition to chaos arises from the limit between rocking and tumbling motion of the body known in this case. In both instances, the chaos may be detected both in the body motion and in the vortex motion. The effect of increasing body mass at a fixed body shape is to damp the chaos.

scholarly journals Self-rechargeable cardiac pacemaker system with triboelectric nanogenerators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hanjun Ryu ◽  
Hyun-moon Park ◽  
Moo-Kang Kim ◽  
Bosung Kim ◽  
Hyoun Seok Myoung ◽  
...  
Keyword(s):  
Medical Devices ◽  
Mechanical Energy ◽  
Cardiac Pacemaker ◽  
Operation Time ◽  
Lithium Ion ◽  
The Body ◽  
Body Motion ◽  
Triboelectric Nanogenerator ◽  
Implantable Medical Devices ◽  
Energy Harvesters

AbstractSelf-powered implantable devices have the potential to extend device operation time inside the body and reduce the necessity for high-risk repeated surgery. Without the technological innovation of in vivo energy harvesters driven by biomechanical energy, energy harvesters are insufficient and inconvenient to power titanium-packaged implantable medical devices. Here, we report on a commercial coin battery-sized high-performance inertia-driven triboelectric nanogenerator (I-TENG) based on body motion and gravity. We demonstrate that the enclosed five-stacked I-TENG converts mechanical energy into electricity at 4.9 μW/cm3 (root-mean-square output). In a preclinical test, we show that the device successfully harvests energy using real-time output voltage data monitored via Bluetooth and demonstrate the ability to charge a lithium-ion battery. Furthermore, we successfully integrate a cardiac pacemaker with the I-TENG, and confirm the ventricle pacing and sensing operation mode of the self-rechargeable cardiac pacemaker system. This proof-of-concept device may lead to the development of new self-rechargeable implantable medical devices.

A Parametric Study of Low-Frequency Damping of Mooring System

2014 ◽  
Author(s):  
Minglu Chen ◽  
Shan Huang ◽  
Nigel Baltrop ◽  
Ji Chunyan ◽  
Liangbi Li
Keyword(s):  
Low Frequency ◽  
Structure Design ◽  
The Body ◽  
Body Motion ◽  
Mooring Line ◽  
Offshore Structure ◽  
Frequency Oscillation ◽  
Low Frequency Oscillation ◽  
Line System ◽  
Irregular Wave

Mooring line damping plays an important role to the body motion of moored floating platforms. Meanwhile, it can also make contributions to optimize the mooring line system. Accurate assessment of mooring line damping is thus an essential issue for offshore structure design. However, it is difficult to determine the mooring line damping based on theoretical methods. This study considers the parameters which have impact on mooring-induced damping. In the paper, applying Morison formula to calculate the drag and initial force on the mooring line, its dynamic response is computed in the time domain. The energy dissipation of the mooring line due to the viscosity was used to calculate mooring-induced damping. A mooring line is performed with low-frequency oscillation only, the low-frequency oscillation superimposed with regular and irregular wave-frequency motions. In addition, the influences of current velocity, mooring line pretension and different water depths are taken into account.

BIOMECHANICAL ANALYSIS OF THE STANDING LONG JUMP

2003 ◽  
Vol 15 (05) ◽  
pp. 186-192 ◽  
Author(s):  
WEN-LAN WU ◽  
JIA-HROUNG WU ◽  
HWAI-TING LIN ◽  
GWO-JAW WANG
Keyword(s):  
Knee Joint ◽  
Motion Analysis ◽  
Joint Angle ◽  
Three Dimensional ◽  
The Body ◽  
Initial Angle ◽  
Knee Joint Angle ◽  
Standing Long Jump ◽  
Long Jump ◽  
Arm Motion

The purposes of the present study were to (1) investigate the effects of the arm movement and initial knee joint angle employed in standing long jump by the ground reaction force analysis and three-dimensional motion analysis; and (2) investigate how the jump performance of the female gender related to the body configuration. Thirty-four healthy adult females performed standing long jump on a force platform with full effort. Body segment and joint angles were analyzed by three-dimensional motion analysis system. Using kinetic and kinematic data, the trajectories on mass center of body, knee joint angle, magnitude of peak takeoff force, and impulse generation in preparing phase were calculated. Average standing long jump performances with free arm motion were +1.5 times above performance with restricted arm motion in both knee initial angles. The performances with knee 90° initial flexion were +1.2 times above performance with knee 45° initial flexion in free and restricted arm motions. Judging by trajectories of the center mass of body (COM), free arm motion improves jump distance by anterior displacement of the COM in starting position. The takeoff velocity with 90° knee initial angle was as much as 11% higher than in with 45° knee initial angle. However, the takeoff angles on the COM trajectory showed no significant differences between each other. It was found that starting jump from 90° bend knee relatively extended the time that the force is applied by the leg muscles. To compare the body configurations and the jumping scores, there were no significant correlations between jump scores and anthropometry data. The greater muscle mass or longer leg did not correlated well with the superior jumping performance.

A Semi-Autonomous Quadruped Robot for Performing Disinfection in Cluttered Environments

2021 ◽  
Author(s):  
Yiyu Chen ◽  
Abhinav Pandey ◽  
Zhiwei Deng ◽  
Anthony Nguyen ◽  
Ruiqi Wang ◽  
...  
Keyword(s):  
Vision System ◽  
Quadruped Robot ◽  
Simulation Software ◽  
The Body ◽  
Body Motion ◽  
Daily Routine ◽  
Public And Private ◽  
Cluttered Environments ◽  
Integrated Simulation ◽  
Human Labor

Abstract The global COVID-19 pandemic has inevitably made disinfection a daily routine to ensure the safety of public and private spaces. However, the existing disinfection procedures are time-consuming and require intensive human labor to apply chemical-based disinfectant onto contaminated surfaces. In this paper, a robot disinfection system is presented to increase the automation of the disinfection task to assist humans in performing routine disinfection safely and efficiently. This paper presents a semi-autonomous quadruped robot called LASER-D for performing disinfection in cluttered environments. The robot is equipped with a spray-based disinfection system and leverages the body motion to control the spray action without an extra stabilization mechanism. The spraying unit is mounted on the robot’s back and controlled by the robot computer. The control architecture is designed based on force control, resulting in navigating rough terrains and the flexibility in controlling the body motion during standing and walking for the disinfection task. The robot also uses the vision system to improve localization and maintain desired distance to the disinfection surface. The system incorporates image processing capability to evaluate disinfected regions with high accuracy. This feedback is then used to adjust the disinfection plan to guarantee that all assigned areas are disinfected properly. The system is also equipped with highly integrated simulation software to design, simulate and evaluate disinfection plans effectively. This work has allowed the robot to successfully carry out effective disinfection experiments while safely traversing through cluttered environments, climb stairs/slopes, and navigate on slippery surfaces.

The Global Motion of a Rigid Body Subject to Periodic Body-Fixed Torques

1995 ◽  
Author(s):  
X. Tong ◽  
B. Tabarrok
Keyword(s):  
Rigid Body ◽  
Equations Of Motion ◽  
Melnikov Method ◽  
The Body ◽  
Body Motion ◽  
Heteroclinic Orbits ◽  
Coordinate Frame ◽  
Global Motion ◽  
Stable And Unstable Manifolds ◽  
Body Subject

Abstract In this paper the global motion of a rigid body subject to small periodic torques, which has a fixed direction in the body-fixed coordinate frame, is investigated by means of Melnikov’s method. Deprit’s variables are introduced to transform the equations of motion into a form describing a slowly varying oscillator. Then the Melnikov method developed for the slowly varying oscillator is used to predict the transversal intersections of stable and unstable manifolds for the perturbed rigid body motion. It is shown that there exist transversal intersections of heteroclinic orbits for certain ranges of parameter values.

scholarly journals Responses of Anterior Superior Temporal Polysensory (STPa) Neurons to “Biological Motion” Stimuli

1994 ◽  
Vol 6 (2) ◽  
pp. 99-116 ◽  
Author(s):  
M. W. Oram ◽  
D. I. Perrett
Keyword(s):  
Biological Motion ◽  
Temporal Cortex ◽  
The Body ◽  
Body Motion ◽  
Whole Body ◽  
Global Pattern ◽  
Lighting Conditions ◽  
Specific Direction ◽  
Direction Of Movement ◽  
Light Stimuli

Cells have been found in the superior temporal polysensory area (STPa) of the macaque temporal cortex that are selectively responsive to the sight of particular whole body movements (e.g., walking) under normal lighting. These cells typically discriminate the direction of walking and the view of the body (e.g., left profile walking left). We investigated the extent to which these cells are responsive under “biological motion” conditions where the form of the body is defined only by the movement of light patches attached to the points of limb articulation. One-third of the cells (25/72) selective for the form and motion of walking bodies showed sensitivity to the moving light displays. Seven of these cells showed only partial sensitivity to form from motion, in so far as the cells responded more to moving light displays than to moving controls but failed to discriminate body view. These seven cells exhibited directional selectivity. Eighteen cells showed statistical discrimination for both direction of movement and body view under biological motion conditions. Most of these cells showed reduced responses to the impoverished moving light stimuli compared to full light conditions. The 18 cells were thus sensitive to detailed form information (body view) from the pattern of articulating motion. Cellular processing of the global pattern of articulation was indicated by the observations that none of these cells were found sensitive to movement of individual limbs and that jumbling the pattern of moving limbs reduced response magnitude. A further 10 cells were tested for sensitivity to moving light displays of whole body actions other than walking. Of these cells 5/10 showed selectivity for form displayed by biological motion stimuli that paralleled the selectivity under normal lighting conditions. The cell responses thus provide direct evidence for neural mechanisms computing form from nonrigid motion. The selectivity of the cells was for body view, specific direction, and specific type of body motion presented by moving light displays and is not predicted by many current computational approaches to the extraction of form from motion.

scholarly journals Perception of the dynamic visual vertical during sinusoidal linear motion

2017 ◽  
Vol 118 (4) ◽  
pp. 2499-2506 ◽  
Author(s):  
A. Pomante ◽  
L. P. J. Selen ◽  
W. P. Medendorp
Keyword(s):  
Vestibular System ◽  
Spatial Orientation ◽  
Linear Acceleration ◽  
The Body ◽  
Body Motion ◽  
Whole Body ◽  
Linear Motion ◽  
Modeling Framework ◽  
Visual Vertical ◽  
The Brain

The vestibular system provides information for spatial orientation. However, this information is ambiguous: because the otoliths sense the gravitoinertial force, they cannot distinguish gravitational and inertial components. As a consequence, prolonged linear acceleration of the head can be interpreted as tilt, referred to as the somatogravic effect. Previous modeling work suggests that the brain disambiguates the otolith signal according to the rules of Bayesian inference, combining noisy canal cues with the a priori assumption that prolonged linear accelerations are unlikely. Within this modeling framework the noise of the vestibular signals affects the dynamic characteristics of the tilt percept during linear whole-body motion. To test this prediction, we devised a novel paradigm to psychometrically characterize the dynamic visual vertical—as a proxy for the tilt percept—during passive sinusoidal linear motion along the interaural axis (0.33 Hz motion frequency, 1.75 m/s2peak acceleration, 80 cm displacement). While subjects ( n=10) kept fixation on a central body-fixed light, a line was briefly flashed (5 ms) at different phases of the motion, the orientation of which had to be judged relative to gravity. Consistent with the model’s prediction, subjects showed a phase-dependent modulation of the dynamic visual vertical, with a subject-specific phase shift with respect to the imposed acceleration signal. The magnitude of this modulation was smaller than predicted, suggesting a contribution of nonvestibular signals to the dynamic visual vertical. Despite their dampening effect, our findings may point to a link between the noise components in the vestibular system and the characteristics of dynamic visual vertical.NEW & NOTEWORTHY A fundamental question in neuroscience is how the brain processes vestibular signals to infer the orientation of the body and objects in space. We show that, under sinusoidal linear motion, systematic error patterns appear in the disambiguation of linear acceleration and spatial orientation. We discuss the dynamics of these illusory percepts in terms of a dynamic Bayesian model that combines uncertainty in the vestibular signals with priors based on the natural statistics of head motion.

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