scholarly journals Pullback $ \mathcal{D} $-attractors of the three-dimensional non-autonomous micropolar equations with damping

2022 ◽  
Vol 30 (1) ◽  
pp. 314-334
Author(s):  
Xiaojie Yang ◽  
◽  
Hui Liu ◽  
Haiyun Deng ◽  
Chengfeng Sun ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Periodic Domain ◽  
Damping Term ◽  
External Forces

<abstract><p>In this paper, we consider the three-dimensional non-autonomous micropolar equations with damping term in periodic domain $ \mathbb{T}^{3} $. By assuming external forces satisfy certain condtions, the existence of pullback $ \mathcal{D} $-attractors for the three-dimensional non-autonomous micropolar equations with damping term is proved in $ V_{1}\times V_{2} $ and $ H^{2}\times H^{2} $ with $ 3 &lt; \beta &lt; 5 $.</p></abstract>

Energy Harvesting Aspects of Irregular Vibrating Forces Acting on Piezoelectric Devices

2015 ◽  
pp. 143-158
Author(s):  
Alessandro Massaro
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Materials ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Output Current ◽  
Vibrating System ◽  
External Forces ◽  
Piezoelectric Devices ◽  
Three Dimensional Space

After a brief introduction of piezoelectric materials, this chapter focuses on the characterization of vibrating freestanding piezoelectric AlN devices forced by different external forces acting simultaneously. The analyzed vibrating forces are applied mainly to piezoelectric freestanding structures stimulated by irregular vibration phenomena. Particular kinds of theoretical noise signals are commented. The goal of the chapter is to analyze the effect of the noise in order to model the chaotic vibrating system and to predict the output current signals. Moreover, the author also shows a possible alternative way to detect different vibrating force directions in the three dimensional space by means of curved piezoelectric layouts.

scholarly journals Translocation through a narrow pore under a pulling force

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mohammadreza Niknam Hamidabad ◽  
Rouhollah Haji Abdolvahab
Keyword(s):  
Interaction Energy ◽  
External Force ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Major Effect ◽  
Translocation Time ◽  
Polymer Translocation ◽  
Pulling Force ◽  
External Forces ◽  
Polymer Shape

AbstractWe employ a three-dimensional molecular dynamics to simulate a driven polymer translocation through a nanopore by applying an external force, for four pore diameters and two external forces. To see the polymer and pore interaction effects on translocation time, we studied nine interaction energies. Moreover, to better understand the simulation results, we investigate polymer center of mass, shape factor and the monomer spatial distribution through the translocation process. Our results reveal that increasing the polymer-pore interaction energy is accompanied by an increase in the translocation time and decrease in the process rate. Furthermore, for pores with greater diameter, the translocation becomes faster. The shape analysis of the polymer indicates that the polymer shape is highly sensitive to the interaction energy. In great interactions, the monomers come close to the pore from both sides. As a result, the translocation becomes fast at first and slows down at last. Overall, it can be concluded that the external force does not play a major role in the shape and distribution of translocated monomers. However, the interaction energy between monomer and nanopore has a major effect especially on the distribution of translocated monomers on the trans side.

scholarly journals Strong Solutions of the Incompressible Navier–Stokes–Voigt Model

Mathematics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 181
Author(s):  
Evgenii S. Baranovskii
Keyword(s):  
Three Dimensional ◽  
Strong Solutions ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Navier Stokes ◽  
Evolutionary Equation ◽  
Long Time ◽  
Special Basis ◽  
External Forces ◽  
Initial Boundary Value

This paper deals with an initial-boundary value problem for the Navier–Stokes–Voigt equations describing unsteady flows of an incompressible non-Newtonian fluid. We give the strong formulation of this problem as a nonlinear evolutionary equation in Sobolev spaces. Using the Faedo–Galerkin method with a special basis of eigenfunctions of the Stokes operator, we construct a global-in-time strong solution, which is unique in both two-dimensional and three-dimensional domains. We also study the long-time asymptotic behavior of the velocity field under the assumption that the external forces field is conservative.

A Study of Anti-Rolling Tank on Floating Vessel

2016 ◽  
Author(s):  
Kyung Sung Kim ◽  
Byung Hyuk Lee ◽  
Moo-Hyun Kim ◽  
Jong-Chun Park ◽  
Han Suk Choi
Keyword(s):  
Volterra Series ◽  
Three Dimensional ◽  
Ship Motion ◽  
Simulation Program ◽  
Linear Potential ◽  
Hydrodynamic Coefficients ◽  
Acceleration Data ◽  
Moving Particle ◽  
Vessel Motion ◽  
External Forces

Active anti-rolling tank (ART) is sophisticated equipment on a floating vessel to reduce roll motion for the slender ship-shape vessel. Three-dimensional panel based diffraction and radiation linear potential program employed to obtain hydrodynamic coefficients of floating vessel. For the ship motion, a BEM (Boundary Element Method)-based ship motion program was used and inner sloshing effects were conducted by a particle-based CFD (Computational Fluid Dynamics) program which is the Moving Particle Semi-implicit (MPS). By using panel program, the hydrodynamic coefficients were obtained in frequency domain, and then were converted into time domain ship motion simulation program. In this procedure, time memory effect was considered by Volterra series expansion. The ship motion program and sloshing program was coupled dynamically; inner tank received displacement, velocity and acceleration data from ship motion program and use them for inner tank motion, while the ship motion program was waiting external forces due to sloshing impact loads and inertia forces/moments from sloshing simulation program. Thus, two programs run simultaneously and allowed real time coupling effects of inner sloshing on vessel motion. By comparing response amplitude operator (RAO) of the vessel without anti-rolling tank, it was shown both values have good agreement. And then comparing between vessels with and without anti-rolling tank, it is shown that the effects of ART changed and shift RAOs. Furthermore, by changing the location of ART, location effects of ART were also investigated.

scholarly journals Three-dimensional printing, muscles, and skeleton: mechanical functions of living wood

2019 ◽  
Vol 70 (14) ◽  
pp. 3453-3466 ◽  
Author(s):  
Bernard Thibaut
Keyword(s):  
Additive Manufacturing ◽  
Field Experiments ◽  
Secondary Growth ◽  
Three Dimensional ◽  
Wood Properties ◽  
Force Generation ◽  
Three Dimensional Printing ◽  
Pipe System ◽  
External Forces ◽  
Dimensional Printing

AbstractWood is well defined as an engineering material. However, living wood in the tree is often regarded only as a passive skeleton consisting of a sophisticated pipe system for the ascent of sap and a tree-like structure made of a complex material to resist external forces. There are two other active key roles of living wood in the field of biomechanics: (i) additive manufacturing of the whole structure by cell division and expansion, and (ii) a ‘muscle’ function of living fibres or tracheids generating forces at the sapwood periphery. The living skeleton representing most of the sapwood is a mere accumulation of dead tracheids and libriform fibres after their programmed cell death. It keeps a record of the two active roles of living wood in its structure, chemical composition, and state of residual stresses. Models and field experiments define four biomechanical traits based on stem geometry and parameters of wood properties resulting from additive manufacturing and force generation. Geometric parameters resulting from primary and secondary growth play the larger role. Passive wood properties are only secondary parameters, while dissymmetric force generation is key for movement, posture control, and tree reshaping after accidents.

Estimation of general three-dimensional motion of an unknown rigid body under no external forces and moments

1994 ◽  
Vol 9 (6) ◽  
pp. 675-691 ◽  
Author(s):  
Yasuhiro Masutani ◽  
Yasuhiro Okada ◽  
Takeshi Iwatsu ◽  
Hiroshi Ikeda ◽  
Fumio Miyazaki
Keyword(s):  
Rigid Body ◽  
Three Dimensional ◽  
External Forces

The Ship-Routing Optimization Based on the Three-Dimensional Modified Isochrone Method

2013 ◽  
Author(s):  
Yu-Hsien Lin ◽  
Ming-Chung Fang
Keyword(s):  
North Pacific Ocean ◽  
Routing Algorithm ◽  
Three Dimensional ◽  
Parametric Roll ◽  
Ship Routing ◽  
Routing Optimization ◽  
The North ◽  
Dynamic Forces ◽  
External Forces ◽  
The North Pacific

In this paper, the authors proposed a ship weather-routing algorithm based on the composite influence of dynamic forces, i.e. wind, wave and current forces, for determining the optimized transoceanic voyages. Our developed routing algorithm, three-dimensional modified isochrones (3DMI) method, utilizes the recursive forward technique and floating grid system for both the east- and west-bound ship routes in the North Pacific Ocean. In order to achieve the goals of minimized fuel-consumption or the maximized-safety routes for the transoceanic voyages, two sailing methods are applied as the prerequisite routes in the earth coordinate systems. The illustrative analysis of ship routes has been presented and discussed based on the realistic constraints, such as the presence of land boundaries, non-navigable sea, external forces, parametric roll responses as well as ship speed loss. As a result, the proposed calculation is verified to be effective for the optimized sailings by adjusting the weighting parameters in the objective functions.

The two mechanisms of intercostal muscle action on the lung

2004 ◽  
Vol 96 (2) ◽  
pp. 483-488 ◽  
Author(s):  
Theodore A. Wilson ◽  
Andre De Troyer
Keyword(s):  
Three Dimensional ◽  
Intercostal Muscle ◽  
Muscle Action ◽  
Opening Pressure ◽  
Rib Cage ◽  
Intercostal Muscles ◽  
Airway Opening ◽  
The Difference ◽  
External Forces

The mechanisms of respiratory action of the intercostal muscles were studied by measuring the effect of external forces (F) applied to the ribs and by modeling the effect of F exerted by the intercostal muscles. In five dogs, with the airway occluded, cranial F were applied to individual rib pairs, from the 2nd to the 11th rib pair, and the change in airway opening pressure (Pao) was measured. The ratio Pao/F increases with increasing rib number in the upper ribs (2nd to 5th) and decreases in the lower ribs (5th to 11th). These data were incorporated into a model for the geometry of the ribs and intercostal muscles, and Pao/F was calculated from the model. For interspaces 2-8, the calculated values agree reasonably well with previously measured values. From the modeling, two mechanisms of intercostal muscle action are identified. One is the well-known Hamberger mechanism, modified to account for the three-dimensional geometry of the rib cage. This mechanism depends on the slant of an intercostal muscle relative to the ribs and on the resulting difference between the moments applied to the upper and lower ribs that bound each interspace. The second is a new mechanism that depends on the difference between the values of Pao/F for the upper and lower ribs.

The Mechanics of Ideal Forming

1994 ◽  
Vol 61 (1) ◽  
pp. 176-181 ◽  
Author(s):  
K. Chung ◽  
O. Richmond
Keyword(s):  
Process Design ◽  
Three Dimensional ◽  
Field Equations ◽  
Starting Point ◽  
Deformation Processes ◽  
External Forces ◽  
Minimum Work ◽  
Yield Conditions ◽  
The Ideal

In this paper, the mechanics of ideal forming theory are summarized for general, three-dimensional, nonsteady processes. This theory has been developed for the initial stages of designing deformation processes. The objectives is to directly determine configurations, both initial and intermediate, that are required to ideally form a specified final shape. In the proposed theory, material elements are prescribed to deform along minimum plastic work paths, assuming that the materials have optimum formabilities in such paths. Then, the ideal forming processes are obtained so as to have the most uniform strain distributions in final products without shear tractions. As solutions, the theory provides the evolution of intermediate shapes of products and external forces as well as optimum strain distributions. Since the requirement of ideal forming to follow minimum work paths involves an over determination of the field equations, the theory places constraints on constitutive and boundary conditions. For example, tool interfaces must be frictionless and yield conditions must have vertices to achieve self-equilibrating three-dimensional deformations in most cases. Despite these constraints, the theory is believed to provide a useful starting point for deformation process design.

scholarly journals Optimization-Based Biomechanical Evaluation of Isometric Exertions on a Brake Wheel

1993 ◽  
Vol 37 (10) ◽  
pp. 693-696 ◽  
Author(s):  
Christian A. Johnson ◽  
Jeffrey C. Woldstad
Keyword(s):  
Repeated Measures ◽  
Three Dimensional ◽  
Compressive Force ◽  
Biomechanical Model ◽  
The Body ◽  
Body Posture ◽  
Muscle Forces ◽  
Left Hand ◽  
Lumbar Muscle ◽  
External Forces

A static three-dimensional low-back biomechanical model was developed to estimate the levels of compressive force on the L3/L4 spinal joint during an experiment that simulated wheel turning. We recorded three-dimensional body posture and the resultant forces at the hands for analysis by the model. The model employed a standard link analysis procedure to resolve the external forces acting on the body to a resultant moment about L3/L4. The model then implemented an optimization algorithm to estimate the internal lumbar muscle forces generated to resist the external forces. The muscle forces and external forces were added to arrive at a prediction of compressive force at L3/L4. The experiment investigated the effects of general body posture, left hand grip, gender, and hand brake torque level upon predicted compressive force at L3/L4. A repeated measures analysis of variance (ANOVA) revealed all but one main effect and some interaction effects to be significant at p<0.05. Average predicted L3/L4 compressive forces at maximum wheel torque levels ranged from 1644N for females to 6926N for large males.

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