scholarly journals Tunnel-tube and Fourier methods for measuring three-dimensional medium reaction force in burrowing animals

2019 ◽  
Vol 222 (23) ◽  
pp. jeb213553
Author(s):  
Alexis Moore Crisp ◽  
Clinton J. Barnes ◽  
David V. Lee
Keyword(s):  
Reaction Force ◽  
Three Dimensional ◽  
Fourier Methods

An Image Reconstruction System Applied to High Voltage Microscopy

1975 ◽  
Vol 33 ◽  
pp. 292-293
Author(s):  
D. E. Johnson
Keyword(s):  
High Voltage ◽  
Prior Information ◽  
Block Diagram ◽  
Three Dimensional ◽  
Real Space ◽  
Two Dimensional ◽  
Efficient Manner ◽  
Fourier Methods ◽  
Tilt Series ◽  
Methods Of Reconstruction

Increased specimen penetration; the principle advantage of high voltage microscopy, is accompanied by an increased need to utilize information on three dimensional specimen structure available in the form of two dimensional projections (i.e. micrographs). We are engaged in a program to develop methods which allow the maximum use of information contained in a through tilt series of micrographs to determine three dimensional speciman structure.In general, we are dealing with structures lacking in symmetry and with projections available from only a limited span of angles (±60°). For these reasons, we must make maximum use of any prior information available about the specimen. To do this in the most efficient manner, we have concentrated on iterative, real space methods rather than Fourier methods of reconstruction. The particular iterative algorithm we have developed is given in detail in ref. 3. A block diagram of the complete reconstruction system is shown in fig. 1.

scholarly journals Gait Disorders In Patients After Polytrauma

2015 ◽  
Vol 69 (1-2) ◽  
pp. 27-32
Author(s):  
Ruta Jakušonoka ◽  
Zane Pavāre ◽  
Andris Jumtiņš ◽  
Aleksejs Smolovs ◽  
Tatjana Anaņjeva
Keyword(s):  
Ground Reaction Force ◽  
Knee Flexion ◽  
Reaction Force ◽  
Three Dimensional ◽  
Step Length ◽  
Vertical Load ◽  
Lower Limb Injuries ◽  
Limb Injuries ◽  
Stance Time ◽  
Polytrauma Patients

Abstract Evaluation of the gait of patients after polytrauma is important, as it indicates the ability of patients to the previous activities and work. The aim of our study was to evaluate the gait of patients with lower limb injuries in the medium-term after polytrauma. Three-dimensional instrumental gait analysis was performed in 26 polytrauma patients (16 women and 10 men; mean age 38.6 years), 14 to 41 months after the trauma. Spatio-temporal parameters, motions in pelvis and lower extremities joints in sagittal plane and vertical load ground reaction force were analysed. Gait parameters in polytrauma patients were compared with a healthy control group. Polytrauma patients in the injured side had decreased step length, cadence, hip extension, maximum knee flexion, vertical load ground reaction force, and increased stance time and pelvic anterior tilt; in the uninjured side they had decreased step length, cadence, maximum knee flexion, vertical load ground reaction force and increased stance time (p < 0.05). The use of the three-dimensional instrumental gait analysis in the evaluation of polytrauma patients with lower limb injuries consequences makes it possible to identify the gait disorders not only in the injured, but also in the uninjured side.

Die Röntgenstrukturanalyse von (CO)9Co3CΟΒΒr2Ν(C5)3. X-ray Structure Analysis of (CO)9Co3COBBr2N(C2H5)3

1976 ◽  
Vol 31 (3) ◽  
pp. 342-344 ◽  
Author(s):  
Volker Bätzel
Keyword(s):  
Least Squares ◽  
Structure Analysis ◽  
Reliability Index ◽  
Three Dimensional ◽  
Diagonal Matrix ◽  
Crystal Data ◽  
Block Diagonal Matrix ◽  
Fourier Methods ◽  
Space Group ◽  
X Ray

Using three dimensional X-ray data collected on a four circle diffractometer, the structure of (CO)9Co3COBBr2N(C2H5)3 was solved by Patterson and Fourier methods. Least squares refinement with a block-diagonal matrix leads to a reliability index of R = 10.7%. Crystal data: α = 13.277(6) Å, b = 10.17(1) Å, c = 9.22(2) Å; α = 91.12(6)°, β = 87.61(4)°, γ = 98.79(2)°; space group P1̅; Z = 2; V = 1229,7 Å3; Dx = 1.97 gcm-3.

scholarly journals Gutenberg Gait Database, a ground reaction force database of level overground walking in healthy individuals

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Fabian Horst ◽  
Djordje Slijepcevic ◽  
Marvin Simak ◽  
Wolfgang I. Schöllhorn
Keyword(s):  
Ground Reaction Force ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Three Dimensional ◽  
Human Gait ◽  
Healthy Individuals ◽  
Overground Walking ◽  
Gait Patterns ◽  
Specific Factors ◽  
Gait Database

AbstractThe Gutenberg Gait Database comprises data of 350 healthy individuals recorded in our laboratory over the past seven years. The database contains ground reaction force (GRF) and center of pressure (COP) data of two consecutive steps measured - by two force plates embedded in the ground - during level overground walking at self-selected walking speed. The database includes participants of varying ages, from 11 to 64 years. For each participant, up to eight gait analysis sessions were recorded, with each session comprising at least eight gait trials. The database provides unprocessed (raw) and processed (ready-to-use) data, including three-dimensional GRF and two-dimensional COP signals during the stance phase. These data records offer new possibilities for future studies on human gait, e.g., the application as a reference set for the analysis of pathological gait patterns, or for automatic classification using machine learning. In the future, the database will be expanded continuously to obtain an even larger and well-balanced database with respect to age, sex, and other gait-specific factors.

scholarly journals A Three-Dimensional Printed Foot Orthosis for Flexible Flatfoot: An Exploratory Biomechanical Study on Arch Support Reinforcement and Undercut

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5297
Author(s):  
Ka-Wing Cheng ◽  
Yinghu Peng ◽  
Tony Lin-Wei Chen ◽  
Guoxin Zhang ◽  
James Chung-Wai Cheung ◽  
...  
Keyword(s):  
Peak Pressure ◽  
Reaction Force ◽  
Three Dimensional ◽  
Biomechanical Study ◽  
Rank Test ◽  
Arch Height ◽  
Vertical Ground Reaction Force ◽  
Flexible Flatfoot ◽  
Arch Support ◽  
Foot Orthosis

The advancement of 3D printing and scanning technology enables the digitalization and customization of foot orthosis with better accuracy. However, customized insoles require rectification to direct control and/or correct foot deformity, particularly flatfoot. In this exploratory study, we aimed at two design rectification features (arch stiffness and arch height) using three sets of customized 3D-printed arch support insoles (R+U+, R+U−, and R−U+). The arch support stiffness could be with or without reinforcement (R+/−) and the arch height may or may not have an additional elevation, undercutting (U+/−), which were compared to the control (no insole). Ten collegiate participants (four males and six females) with flexible flatfoot were recruited for gait analysis on foot kinematics, vertical ground reaction force, and plantar pressure parameters. A randomized crossover trial was conducted on the four conditions and analyzed using the Friedman test with pairwise Wilcoxon signed-rank test. Compared to the control, there were significant increases in peak ankle dorsiflexion and peak pressure at the medial midfoot region, accompanied by a significant reduction in peak pressure at the hindfoot region for the insole conditions. In addition, the insoles tended to control hindfoot eversion and forefoot abduction though the effects were not significant. An insole with stronger support features (R+U+) did not necessarily produce more favorable outcomes, probably due to over-cutting or impingement. The outcome of this study provides additional data to assist the design rectification process. Future studies should consider a larger sample size with stratified flatfoot features and covariating ankle flexibility while incorporating more design features, particularly medial insole postings.

scholarly journals Three-dimensional data-tracking simulations of sprinting using a direct collocation optimal control approach

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10975
Author(s):  
Nicos Haralabidis ◽  
Gil Serrancolí ◽  
Steffi Colyer ◽  
Ian Bezodis ◽  
Aki Salo ◽  
...  
Keyword(s):  
Experimental Data ◽  
Reaction Force ◽  
Three Dimensional ◽  
Contact Model ◽  
Model Parameters ◽  
Ground Contact ◽  
Control Approach ◽  
Average Percentage ◽  
Data Tracking ◽  
The Individual

Biomechanical simulation and modelling approaches have the possibility to make a meaningful impact within applied sports settings, such as sprinting. However, for this to be realised, such approaches must first undergo a thorough quantitative evaluation against experimental data. We developed a musculoskeletal modelling and simulation framework for sprinting, with the objective to evaluate its ability to reproduce experimental kinematics and kinetics data for different sprinting phases. This was achieved by performing a series of data-tracking calibration (individual and simultaneous) and validation simulations, that also featured the generation of dynamically consistent simulated outputs and the determination of foot-ground contact model parameters. The simulated values from the calibration simulations were found to be in close agreement with the corresponding experimental data, particularly for the kinematics (average root mean squared differences (RMSDs) less than 1.0° and 0.2 cm for the rotational and translational kinematics, respectively) and ground reaction force (highest average percentage RMSD of 8.1%). Minimal differences in tracking performance were observed when concurrently determining the foot-ground contact model parameters from each of the individual or simultaneous calibration simulations. The validation simulation yielded results that were comparable (RMSDs less than 1.0° and 0.3 cm for the rotational and translational kinematics, respectively) to those obtained from the calibration simulations. This study demonstrated the suitability of the proposed framework for performing future predictive simulations of sprinting, and gives confidence in its use to assess the cause-effect relationships of technique modification in relation to performance. Furthermore, this is the first study to provide dynamically consistent three-dimensional muscle-driven simulations of sprinting across different phases.

Simulation Research of Top-Hung Mechanism for Open and Close

2014 ◽  
Vol 644-650 ◽  
pp. 416-420
Author(s):  
Xu Zhou ◽  
Ying Wu
Keyword(s):  
Simulation Analysis ◽  
Reaction Force ◽  
Three Dimensional ◽  
Revolute Joint ◽  
Initial Values ◽  
Support Reaction ◽  
Vertical Location ◽  
Optimization Parameters ◽  
Reaction Forces ◽  
Set Up

For the purpose of researching the top-hung mechanism for open and close and the improvement and use of the mechanism, improving the work efficiency, the three-dimensional solid model of the mechanism was established with ADAMS. Each part of the model in ADAMS was set up. Simulation analysis on the working process of the mechanism was achieved. The structure optimization parameters of the mechanism were obtained. The result proves that when the vertical location of the upper endpoint of lid was increased the total support reaction force acting on the lower endpoint of lower rocker by frame reduced. When the horizontal location of revolute joint of lower rocker and frame, the horizontal location of revolute joint of lower rocker and lid were increased the total support reaction forces acting on the lower endpoint of lower rocker by frame added. The sensitivities of the total support reaction forces acting on the lower endpoint of lower rocker by frame on the initial values of the locations of revolute joint of lower rocker and link, the horizontal location of revolute joint of lower rocker and frame are greater. The sensitivities of the total support reaction forces acting on the lower endpoint of lower rocker by frame on the initial values of the vertical location of revolute joint of upper rocker and link, the horizontal location of revolute joint of the lower rocker and lid are smaller. The sensitivity of the total support reaction force acting on the lower endpoint of lower rocker by frame on the initial value of the vertical location of the upper endpoint of lid are least.

Three-dimensional refinement of the structure of β-succinic acid

1959 ◽  
Vol 251 (1267) ◽  
pp. 441-457 ◽  
Keyword(s):  
Succinic Acid ◽  
Three Dimensional ◽  
Molecular Crystals ◽  
Carboxyl Group ◽  
Single Bond ◽  
Fourier Methods ◽  
Angular Oscillation ◽  
Anisotropic Temperature ◽  
Temperature Factors ◽  
Van Der Waals Contacts

The crystal structure of β-succinic acid has been refined by three-dimensional Fourier methods, followed by differential refinements with series-termination corrections and anisotropic temperature factors. The central C—C bond at 1·533 Å is shown not to differ significantly from the length of the single bond in diamond, but the next bond connecting the chain to the carboxyl group, C—COOH, is 1·485 ± 0·013 Å and the contraction here is highly significant. The C—O distances are 1·252 and 1·322 Å, with standard deviations of about 0·012 Å. The main feature of the thermal motion is that the movement in the direction of the hydrogen-bonded molecular columns is very much less than in any other direction in the crystal, and also much less than in pure molecular crystals like benzene or naphthalene. In other directions where van der Waals contacts only exist the movement is greater. There is a molecular angular oscillation of perhaps 9° r.m.s. amplitude about an axis close to the axis of the molecular columns. A difference synthesis in the plane of the oxygen atoms is given which shows the hydrogen atom responsible for hydrogen bonding.

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