The thermodynamics of intracrystalline sorption II. Argon in chabazite

1956 ◽  
Vol 234 (1196) ◽  
pp. 35-45 ◽  
Keyword(s):  
Experimental Data ◽  
Mobile Phase ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Translational Degree ◽  
Sorbed Phase

The experimentally observed isotherms and entropies of the intracrystalline sorbed phase of argon in natural and calcium chabazites are compared with those predicted by models. For sorbate concentrations between approximately θ = 0.1 and 0.7, the experimental data are incompatible with the properties of a localized phase but are in agreement with those of a mobile phase. It is demonstrated that it is impossible for the argon to possess two degrees of translational freedom and that it is best described as having one translational degree of freedom and two vibrational degrees of freedom each with a frequency of 1 x 10 12 to 2 x 10 12 s -1 . The examination of the entropy of the system also shows that at concentrations greater than θ = 0.7 the mobile concept breaks down and it is probable that the translational degree of freedom passes to a vibration due to the mutual caging action of sorbate molecules, so that the phase becomes a system of oscillators.

The thermodynamics of intracrystalline sorption I. Models of the sorbed state

1956 ◽  
Vol 234 (1196) ◽  
pp. 24-34 ◽  
Keyword(s):  
Mobile Phase ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Translational Degree ◽  
Sorbate Concentration ◽  
The Ideal

Three basic models of the intracrystalline sorbed state are discussed: a localized phase, a mobile phase possessing two translational degrees of freedom, and a mobile phase with one translational degree of freedom. The isotherm and entropy of each of these models have been investigated for the ideal phase, and where possible the influence of sorbate-sorbate interactions has been considered. Expressions for the molal and differential entropies of each model are given as a function of sorbate concentration. The method of comparing theoretical isotherms and entropies with experimental observations is outlined.

Design and Evaluation of a Passive Ankle Prosthesis With Rotational Power Generation by a Compliant Coupling Between Leg Deflection and Ankle Rotation

2014 ◽  
Author(s):  
Jacob J. Rice ◽  
Joseph M. Schimmels
Keyword(s):  
Degrees Of Freedom ◽  
Gait Cycle ◽  
The Body ◽  
Degree Of Freedom ◽  
Rotational Degree ◽  
Kinematic Data ◽  
Active Behavior ◽  
Ankle Prosthesis ◽  
Compression Spring ◽  
Translational Degree

This paper presents the design and simulation results of a passive prosthetic ankle prosthesis that has mechanical behavior similar to a natural ankle. The presented design achieves active behavior with powered push-off to propel the body forward. The design contains a conventional compression spring network that allows coupling between two degrees of freedom. There is a translational degree of freedom along the leg and a rotational degree of freedom about the ankle joint. During a standard gait cycle, potential energy from the person’s weight is stored in the spring network from deflection along the leg. The energy is released by the spring network as rotation of the foot. With this design, capping the allowable leg deflection at 15 millimeters produces 45% of the rotational work that a natural ankle will produce. This is based on simulation using published average kinetic and kinematic data from gait analyses.

Bio-Inspired Locomotion of Circular Robots With Diametrically Translating Legs

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Eric Steffan ◽  
Sudeshna Pal ◽  
Tuhin Das
Keyword(s):  
Mobile Robots ◽  
Degrees Of Freedom ◽  
Analytical Framework ◽  
Degree Of Freedom ◽  
Translational Degree ◽  
Simulation Results ◽  
Cellular Locomotion ◽  
Kinetics Of ◽  
Kinematics And Kinetics

Abstract In this paper, we develop an analytical framework for designing the locomotion of mobile robots with a circular core and equispaced diametral legs, each having a radial translational degree of freedom. The mechanism has resemblance with certain cellular locomotion. The robot travels by radial actuation of the legs in a sequential and synchronized manner. Two elementary regimes of motion are first designed using the geometry and degrees of freedom of the mechanism. Overall motion of the robot is generated by repeated switching between the two regimes. The paper addresses both kinematics and kinetics of the mechanism, enabling the prediction of trajectories and computation of constraint as well as actuation forces. Simulation results are provided in support of the theory developed.

Multi-Degree-of-Freedom Modeling of Mechanical Snubbing Systems

2011 ◽  
Author(s):  
Sudhir Kaul
Keyword(s):  
Experimental Data ◽  
Data Collection ◽  
Rigid Body ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
Rigid Frame ◽  
Identification Technique ◽  
Simulation Results ◽  
Stiffness And Damping ◽  
Three Degrees Of Freedom

This paper presents a multi-degree-of-freedom model for the analysis of mechanical snubbing in elastomeric isolators. The model uses a system of elastomeric isolators and snubbers to assemble a rigid body with three degrees-of-freedom to a rigid frame. The isolators are supplemented by the snubbing system so as to limit the displacement of the rigid body in all three directions of motion when the system undergoes transient loading or overloading conditions. The model is piecewise non-linear and uses normalized Bouc-Wen elements in order to capture inherent hysteresis of the elastomeric isolators and the snubbing system as well as the transition in stiffness and damping properties resulting due to inherent coupling between the isolators and the snubbing system. Separate elements are used to model the enhanced stiffness resulting from the snubbing system in the translational directions of motion. A set of elastomeric isolators and snubbing systems is used for data collection, characterization and model validation. The data collection is carried out at multiple strain amplitudes and strain rates. A conventional least squares based parameter identification technique is used for characterization. The completely characterized model is then used for simulating the response of the rigid body and the simulation results are compared to experimental data. The simulation results are found to be in general agreement with the experimental data.

scholarly journals Design and Calibration of a Hall Effect System for Measurement of Six-Degree-of-Freedom Motion within a Stacked Column

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3740
Author(s):  
Olafur Oddbjornsson ◽  
Panos Kloukinas ◽  
Tansu Gokce ◽  
Kate Bourne ◽  
Tony Horseman ◽  
...  
Keyword(s):  
Hall Effect ◽  
Degrees Of Freedom ◽  
Reactor Core ◽  
Degree Of Freedom ◽  
Life Extension ◽  
Scale Model ◽  
Design Development ◽  
Seismic Safety ◽  
Six Degrees Of Freedom ◽  
Six Degree Of Freedom

This paper presents the design, development and evaluation of a unique non-contact instrumentation system that can accurately measure the interface displacement between two rigid components in six degrees of freedom. The system was developed to allow measurement of the relative displacements between interfaces within a stacked column of brick-like components, with an accuracy of 0.05 mm and 0.1 degrees. The columns comprised up to 14 components, with each component being a scale model of a graphite brick within an Advanced Gas-cooled Reactor core. A set of 585 of these columns makes up the Multi Layer Array, which was designed to investigate the response of the reactor core to seismic inputs, with excitation levels up to 1 g from 0 to 100 Hz. The nature of the application required a compact and robust design capable of accurately recording fully coupled motion in all six degrees of freedom during dynamic testing. The novel design implemented 12 Hall effect sensors with a calibration procedure based on system identification techniques. The measurement uncertainty was ±0.050 mm for displacement and ±0.052 degrees for rotation, and the system can tolerate loss of data from two sensors with the uncertainly increasing to only 0.061 mm in translation and 0.088 degrees in rotation. The system has been deployed in a research programme that has enabled EDF to present seismic safety cases to the Office for Nuclear Regulation, resulting in life extension approvals for several reactors. The measurement system developed could be readily applied to other situations where the imposed level of stress at the interface causes negligible material strain, and accurate non-contact six-degree-of-freedom interface measurement is required.

Three-dimensional asymmetric maximum weight lifting prediction considering dynamic joint strength

2021 ◽  
pp. 095441192098703
Author(s):  
Rahid Zaman ◽  
Yujiang Xiang ◽  
Jazmin Cruz ◽  
James Yang
Keyword(s):  
Experimental Data ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Three Dimensional ◽  
Optimization Method ◽  
Weight Lifting ◽  
Joint Torque ◽  
Maximum Weight ◽  
Angular Velocities ◽  
Asymmetric Lifting

In this study, the three-dimensional (3D) asymmetric maximum weight lifting is predicted using an inverse-dynamics-based optimization method considering dynamic joint torque limits. The dynamic joint torque limits are functions of joint angles and angular velocities, and imposed on the hip, knee, ankle, wrist, elbow, shoulder, and lumbar spine joints. The 3D model has 40 degrees of freedom (DOFs) including 34 physical revolute joints and 6 global joints. A multi-objective optimization (MOO) problem is solved by simultaneously maximizing box weight and minimizing the sum of joint torque squares. A total of 12 male subjects were recruited to conduct maximum weight box lifting using squat-lifting strategy. Finally, the predicted lifting motion, ground reaction forces, and maximum lifting weight are validated with the experimental data. The prediction results agree well with the experimental data and the model’s predictive capability is demonstrated. This is the first study that uses MOO to predict maximum lifting weight and 3D asymmetric lifting motion while considering dynamic joint torque limits. The proposed method has the potential to prevent individuals’ risk of injury for lifting.

Research on Simulation Customers Participate Type in Open Innovation

2014 ◽  
Vol 926-930 ◽  
pp. 2054-2057
Author(s):  
Jun Hui He
Keyword(s):  
Open Innovation ◽  
Degrees Of Freedom ◽  
New Products ◽  
Innovation Process ◽  
Degree Of Freedom ◽  
Three Dimensions ◽  
Dynamic Evolution ◽  
Evolution Simulation ◽  
High Degree

This paper proposed customers to participate typology based on three dimensions, which are the customers’ autonomy in the process, the nature of the firm‐customer collaboration, and the stage of the innovation process. Then proposed customers to participate in the type of open innovation framework. Through the static comparative and dynamic evolution simulation found: customers tend to be open to participate in the development of new products pre innovation, the tendency to begin to choose the low participation of degrees of freedom, and ultimately tend to opt for a high degree of freedom to participate.

Analysis of Five-Degree-of-Freedom Robot Arms

1983 ◽  
Vol 105 (1) ◽  
pp. 23-27 ◽  
Author(s):  
K. Sugimoto ◽  
J. Duffy
Keyword(s):  
Arc Welding ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Industrial Robot ◽  
Degree Of Freedom ◽  
Numerical Example ◽  
Robot Arms ◽  
Special Cases ◽  
Computer Controlled ◽  
Five Axes

Many kinds of robot arms with five degrees of freedom are widely used in industry for arc welding, spray painting, assembling etc. It is necessary to be able to compute joint displacements when such devices are computer controlled. A solution to this problem is presented and the analysis is illustrated by a numerical example using the most common industrial robot with five axes. Further, special cases are discussed using screw theory.

Systematic Synthesis and Applications of Novel Multi-Degree-of-Freedom Differential Systems

1992 ◽  
Author(s):  
Sridhar Kota ◽  
Srinivas Bidare
Keyword(s):  
Degrees Of Freedom ◽  
Building Blocks ◽  
Degree Of Freedom ◽  
Differential Systems ◽  
Practical Applications ◽  
Epicyclic Gear ◽  
Differential Mechanism ◽  
Long Time ◽  
Gear Trains ◽  
Drive Systems

Abstract A two-degree-of-freedom differential system has been known for a long time and is widely used in automotive drive systems. Although higher degree-of-freedom differential systems have been developed in the past based on the well-known standard differential, the number of degrees-of-freedom has been severely restricted to 2n. Using a standard differential mechanism and simple epicyclic gear trains as differential building blocks, we have developed novel whiffletree-like differential systems that can provide n-degrees of freedom, where n is any integer greater than two. Symbolic notation for representing these novel differentials is also presented. This paper presents a systematic method of deriving multi-degree-of-freedom differential systems, a three and four output differential systems and some of their practical applications.

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