scholarly journals Tracking the ultrafast nonequilibrium energy flow between electronic and lattice degrees of freedom in crystalline nickel

2020 ◽  
Vol 101 (10) ◽  
Author(s):  
P. Maldonado ◽  
T. Chase ◽  
A. H. Reid ◽  
X. Shen ◽  
R. K. Li ◽  
...  
Keyword(s):  
Energy Flow ◽  
Degrees Of Freedom ◽  
Nonequilibrium Energy

Energy Diagnosis of the Structure of the Demolition Hammer with WoSSo Vibroisolation of a Biomechanical System

2013 ◽  
Vol 588 ◽  
pp. 117-126
Author(s):  
Marian Witalis Dobry
Keyword(s):  
Energy Flow ◽  
Degrees Of Freedom ◽  
Digital Simulation ◽  
Simulation Method ◽  
Interaction Force ◽  
Entire System ◽  
Vibration System ◽  
Model Base ◽  
Diagnostic Research ◽  
Physical And Mathematical Models

The article presents the results of energy diagnosis of the structure of an innovative, mechanized, hand-held demolition tool with application of the Constant Interaction Force Vibroisolation (abbreviated as WoSSO) of a biomechanical system. Sample results refer to the demolition hammer of the weight of 15,6 kg and the frequency of working shocks of 20 Hz. The diagnostic research was to recognise and evaluate the energy and spatial impact of the innovative structure of the hammer provided with anti-vibration system upon human. 3D energy physical and mathematical models of the entire system human demolition hammer with vibroisolation of 18 degrees of freedom were designed and the problem was solved with the digital simulation method. The forces enforcing three directions of vibrations were identified via experiments at the research stand on the model base compliant with the ISO standard and then entered in the simulation program. The obtained results of the energy diagnosis of the structure explained the phenomenon of the energy flow in the examined biomechanical system and confirmed the efficiency of the flow reduction of the energy of vibrations into the human body at all the reduction points in the three directions of vibrations.

Metamaterials With Tunable Stop Bands

2008 ◽  
Author(s):  
H. H. Huang ◽  
C. T. Sun
Keyword(s):  
Energy Flow ◽  
Degrees Of Freedom ◽  
Numerical Solutions ◽  
Mass Density ◽  
Stop Band ◽  
Internal Mass ◽  
Frequency Range ◽  
Negative Mass ◽  
One Dimensional ◽  
Internal Degrees Of Freedom

Metamaterials are materials with manmade microstructures. Recently, researchers have looked at a class of metamaterials whose microstructures contain internal degrees of freedom that are different from those of the macro-medium. These metamaterials exhibit unusual dynamic behavior and if modeled as homogeneous solids then their effective mass densities would become negative in certain frequency range. Specifically, a new stop band in the vicinity of the local resonance frequency of the internal mass in the microstructure would result. In this paper, a one dimensional metamaterial is employed to investigate the meaning of the negative mass density in the material and the energy flow in and out of the microstructure. In addition, numerical solutions are used to illustrate the phenomenon.

scholarly journals Development of Non-Conservative Joints in Beam Networks for Vibration Energy Flow Analysis

2007 ◽  
Vol 14 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Jee-Hun Song ◽  
Suk-Yoon Hong
Keyword(s):  
Energy Flow ◽  
Degrees Of Freedom ◽  
Vibrational Energy ◽  
Flow Analysis ◽  
Energy Flow Analysis ◽  
Internal Loss ◽  
Joint Properties ◽  
Flow Through ◽  
Coupled Structures ◽  
Coupling Angle

Our work aims to find a general solution for the vibrational energy flow through a plane network of beams on the basis of an energy flow analysis. A joint between two semi-infinite beams are modeled by three sets of springs and dashpots. Thus, the results can incorporate the case of complaint and non-conservative in all the three degrees of freedom. In the cases of finite coupled structures connected at a certain angle, the derived non-conservative joints and developed wave energy equation were applied. The joint properties, the frequency, the coupling angle, and the internal loss factor were changed to evaluate the proposed methods for predicting medium-to-high frequency vibrational energy and intensity distributions.

Identification of Energy Dissipation in Structural Joints by Means of the Energy Flow Analysis

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
S. S. Gómez ◽  
A. Metrikine ◽  
B. Carboni ◽  
W. Lacarbonara
Keyword(s):  
Experimental Data ◽  
Energy Dissipation ◽  
Energy Flow ◽  
Degrees Of Freedom ◽  
Flow Analysis ◽  
Low Frequency ◽  
Frequency Range ◽  
Energy Flow Analysis ◽  
Damping Matrix ◽  
Good Agreement

In this paper, identification of energy dissipation in the joints of a lab-scale structure is accomplished. The identification is carried out by means of an energy flow analysis and experimental data. The devised procedure enables to formulate an energy balance in the vicinity of the joints to obtain local energy dissipation. In this paper, a damping matrix based on the locally identified damping coefficients is formulated. The formulated damping matrix is later used in a five-degrees-of-freedom (5DOF) system for validation. The results obtained with the proposed method are in good agreement with the experimental data, especially in the low frequency range.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Representing utility and deploying the body

2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett
Keyword(s):  
Functional Activity ◽  
Degrees Of Freedom ◽  
The Body ◽  
Target Article ◽  
Processing Demands ◽  
The Many

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.

Das Experten-Novizen-Paradigma und die Vertrauenskrise in der Psychologie

2016 ◽  
Vol 23 (4) ◽  
pp. 131-140 ◽  
Author(s):  
Philip Furley ◽  
Karsten Schul ◽  
Daniel Memmert
Keyword(s):  
Degrees Of Freedom

Zusammenfassung. Das Ziel des vorliegenden Beitrages ist es anhand eines vielverwendeten Paradigmas in der Sportwissenschaft – dem Experten-Novizen-Vergleich – zu prüfen, ob die momentane Vertrauenskrise in der Psychologie ebenfalls die Sportpsychologie betreffen könnte. Anhand einer exemplarischen Studie zeigen wir, dass es innerhalb dieses Paradigmas zu kontroversen Befunden kommt, welche durch die vermuteten Ursachen der Vertrauenskrise (Researcher Degrees of Freedom, kleine Stichprobengrößen) erklärt sein könnten. Zusätzlich argumentieren wir, dass weitere Faktoren (Konfundierung, Stichprobengrößen, Rosenthal Effekt, Expertise-Definition) innerhalb dieses Paradigmas die Reproduzierbarkeit von Erkenntnissen in Frage stellen. Wir diskutieren mögliche Maßnahmen, wie die dargestellten Probleme des Experten-Novizen-Paradigmas in zukünftigen Forschungsarbeiten gelöst werden können.

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