Determining Functional Finger Capabilities of Healthy Adults: Comparing Experimental Data to a Biomechanical Model

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Samuel T. Leitkam ◽  
Tamara Reid Bush ◽  
Laura Bix
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Biomechanical Model ◽  
Experimental Models ◽  
Human Hand ◽  
Functional Abilities ◽  
Data Set ◽  
Functional Measures ◽  
Wide Range ◽  
Capture Techniques

The human hand has a wide range of possible functional abilities that can change with age, disease, and injury, and can vary from individual to individual and subsequently can affect a person's quality of life. The objective of this work was to develop a theoretical model of the space that is reachable by the hand, weighted to represent three types of functionality, and to compare this model to an experimental data set obtained from a healthy hand population. A theoretical model, termed the Weighted Fingertip Space, was developed using 50th percentile published hand data and ranges of finger motion. The functional abilities calculated in the model were the abilities to position the fingertip pad, orient the fingertip pad, and apply directional forces through the fingertip pad at all the reachable points in space with respect to the palm. Following the development of this theoretical model, experimental data sets from nine individuals with healthy hands were obtained through motion capture techniques. The experimental data were then compared to the theoretical model. Comparisons between a 50th percentile theoretical model and a subject with a similar sized hand showed good agreement in weighting parameters and overall size and shape of the model spaces. The experimental data set from the entire sample, which ranged from the 2nd to 95th percentile hand sizes, showed resultant models that, on average, reached smaller volumes of space, but yielded higher values of the functional measures within those volumes. Additionally, in comparison to the theoretical model, the variability of the experimental models showed that small changes in hand dimensions and ranges of motion of the finger joints had a large influence in the functional measures of the model. Combined, these results suggest that the modeling technique can calculate functional ability of the hand, but should be used on an individualized basis for evaluating changes in function (e.g., rehabilitation). Further, scaling to hand size has the potential to yield “average” models for larger population samples.

Theoretical, Numerical, and Experimental Study of the Time of Flight Flowmeter

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Ian Gaskin ◽  
Evgeniy Shapiro ◽  
Dimitris Drikakis
Keyword(s):  
Experimental Data ◽  
Response Time ◽  
Flow Rate ◽  
Dynamic Range ◽  
Time Of Flight ◽  
Numerical Data ◽  
Working Fluid ◽  
Independent Function ◽  
Data Set ◽  
Wide Range

Time-of-flight flowmeters offer advantages over other flowmeter types since these are less sensitive to the physical properties of the fluid. However, calibration of the flowmeter for a particular working fluid is still required. A flowmeter that does not require re-calibration with different fluids is desirable in many applications. This paper investigates the performance of a device that measures the time of flight of a heat pulse in a gas stream to determine the flow rate in a pipe. A fusion of the theoretical, experimental, and numerical data is used to suggest a gas-independent correlation function between the response time and flow rate. In particular, the numerical data augmented by the theoretical analysis to account for the wire response time is validated against experimental data and used to further enhance the experimental data set. Nitrogen, helium, and tetrafluoroethane (R134a) are investigated, as these gases provide a wide range of physical and thermodynamic properties. Simulated results match the trends of experimental data well and allow good qualitative analysis. The results also show that using detected pulse width information together with the time of flight can yield a 20% reduction in the errors due to gas type than by using time of flight data alone. This gives a relatively gas-independent function over a dynamic range of 1:400.

Pressure Drop of Liquid-Liquid Taylor Flow in Mini-Scale Tubing

2016 ◽  
Author(s):  
W. Adrugi ◽  
Y. S. Muzychka ◽  
K. Pope
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Pressure Drop ◽  
Flow Rate ◽  
Small Scale ◽  
Flow Rates ◽  
Constant Flow Rate ◽  
Taylor Flow ◽  
Low Viscosity ◽  
Wide Range

In this paper, the pressure drop of liquid-liquid segmented flow in small-scale tubing is investigated with experimental and analytical methods. A theoretical model is developed for describing the total pressure drop as a function of slug length and Capillary number. The experiments are conducted with low Reynolds number flows in horizontal, straight mini-scale tubes. A segmented (Taylor) flow is created using several low viscosity silicone oils (1, 3, 5 cSt) and water with a wide range of flow rates. The experimental setup allows the independent variation of liquid slug lengths. The liquids are injected into the mini-scale tubes at a variable (pulsed) flow rate for one liquid, and a constant flow rate for another liquid. The variation of liquid types and flow rates causes numerous combinations of Prandtl, Reynolds, and Capillary numbers to be tested. The theoretical and experimental data is presented in terms of the dimensionless groups fRe or ΔP* and Le* to predict pressure drop in liquid-liquid Taylor flow. The new experimental data agrees well with the new theoretical model of Taylor flow in miniscale tubes. The results of this paper indicate the pressure drop for Taylor flow is higher than in single-phase flow, likely due to the interfacial effects in liquid slugs.

scholarly journals Theoretical Model for Prediction of Turning Resistance of Tracked Vehicle on Soft Terrain

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhao Ding ◽  
Yaoming Li ◽  
Zhong Tang
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Theoretical Model ◽  
Close Agreement ◽  
Tracked Vehicles ◽  
Ground Pressure ◽  
Wide Range ◽  
Turning Resistance ◽  
The Moment ◽  
Turning Maneuver

Skid-steered tracked vehicles are commonly used in soft agricultural terrain due to its low ground pressure between vehicle tracks and the ground. However, the sliding and sinkage of the track during a turning maneuver causes considerable turning resistance, which reduces the vehicle's turning ability. Therefore, we constructed a theoretical model that predicts the turning resistance of tracked vehicles—under steady-state conditions on soft terrain—accounting for track sinkage effects and track slip and skid. The results demonstrate that the moment of turning resistance decreases with increased track slip and skid ratio but increases with track sinkage depth. The model-predicted moments of turning resistance for the outer and inner tracks—at a given track sinkage depth and track slip and skid ratio—are in reasonably close agreement with available experimental data. This theoretical model can be employed as a predictor for testing the turning resistance of tracked vehicles operating on a wide range of soils.

scholarly journals Random Errors of Tycho Astrometry

1995 ◽  
Vol 166 ◽  
pp. 376-376
Author(s):  
V.V. Makarov ◽  
E. Høg
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Prior Information ◽  
A Priori ◽  
Systematic Errors ◽  
Random Errors ◽  
Likelihood Estimator ◽  
Major Drawback ◽  
Wide Range ◽  
Input Catalogue

The paper focuses on the problem of estimation of Tycho astrometry random errors, caused by photon noise. A theoretical model for the random errors was developed on the basis of the Maximum Likelihood estimator. The model provides a satisfactory agreement with experimental data in the wide range of star magnitudes from 4 to 10 for both vertical and inclined slit transits. It is confirmed theoretically, that for fainter stars, which constitute a half of the Tycho star sample, this model is not valid. Moreover, it is demonstrated that a reliable astrometry could hardly be achieved for these faint stars, were it not for a kind of Bayesian approach which is in fact implemented in the processing. This approach uses implicitly a priori astrometric information on positions of the stars. A major drawback of the method is that it introduces some bias in astrometry estimation, of presently unknown size. Nonetheless, no transfer of systematic errors from the input catalogue is expected, for the used prior information comes from Recognition, hence it is based purely on the satellite's own observations. – The inadequacy of the pure ML theory leads us to correct the model empirically, in order to provide reliable formal errors for the astrometric parameters in the final catalogue, for all Tycho magnitudes. In this way, a rms normalized residual is used for each star individually as a scale factor or correction to the formal covariances. Corrected in this way, formal errors are compared directly with external errors, calculated from absolute differences between the Tycho provisional parallaxes in a 30 months solution and the Hipparcos parallaxes of some 100 000 common stars. Analysis of a standard external error shows that the corrected formal errors are robust, and probably even overestimated.

A Structural Model of the Venous Wall Considering Elastin Anisotropy

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
Rana Rezakhaniha ◽  
Nikos Stergiopulos
Keyword(s):  
Experimental Data ◽  
Smooth Muscle ◽  
Biomechanical Model ◽  
Vascular Wall ◽  
Pressure Force ◽  
Wide Range ◽  
Force Curves ◽  
Longitudinal Stretch ◽  
Venous Wall

The three-dimensional biomechanical behavior of the vascular wall is best described by means of strain energy functions. Significant effort has been devoted lately in the development of structure-based models of the vascular wall, which account for the individual contribution of each major structural component (elastin, collagen, and vascular smooth muscle). However, none of the currently proposed structural models succeeded in simultaneously and accurately describing both the pressure-radius and pressure-longitudinal force curves. We have hypothesized that shortcomings of the current models are, in part, due to unaccounted anisotropic properties of elastin. We extended our previously developed biomechanical model to account for elastin anisotropy. The experimental data were obtained from inflation-extension tests on facial veins of five young white New Zealand rabbits. Tests have been carried out under a fully relaxed state of smooth muscle cells for longitudinal stretch ratios ranging from 100% to 130% of the in vivo length. The experimental data (pressure-radius, pressure-force, and zero-stress-state geometries) provided a complete biaxial mechanical characterization of rabbit facial vein and served as the basis for validating the applicability and accuracy of the new biomechanical model of the venous wall. When only the pressure-radius curves were fitted, both the anisotropic and the isotropic models gave excellent results. However, when both pressure-radius and pressure-force curves are simultaneously fitted, the model with isotropic elastin shows an average weighted residual sum of squares of 8.94 and 23.9 in the outer radius and axial force, respectively, as compared to averages of 6.07 and 4.00, when anisotropic elastin is considered. Both the Alkaike information criterion and Schwartz criterion show that the model with the anisotropic elastin is more successful in predicting the data for a wide range of longitudinal stretch ratios. We conclude that anisotropic description of elastin is required for a full 3D characterization of the biomechanics of the venous wall.

LIQUIDUS THERMO-BAROMETER FOR THE MODELING OF MAGNETITE — MELT EQUILIBRIUM

2018 ◽  
pp. 71-80
Author(s):  
N. S. Aryaeva ◽  
E. V. Koptev-Dvornikov ◽  
D. A. Bychkov
Keyword(s):  
Experimental Data ◽  
Liquidus Temperature ◽  
Vertical Structure ◽  
Maximum Error ◽  
Silicate Melt ◽  
System Of Equations ◽  
Wide Range ◽  
Basaltic Melts ◽  
Multidimensional Statistics

A system of equations of thermobarometer for magnetite-silicate melt equilibrium was obtained by method of multidimensional statistics of 93 experimental data of a magnetite solubility in basaltic melts. Equations reproduce experimental data in a wide range of basalt compositions, temperatures and pressures with small errors. Verification of thermobarometers showed the maximum error in liquidus temperature reproducing does not exceed ±7 °C. The level of cumulative magnetite appearance in the vertical structure of Tsypringa, Kivakka, Burakovsky intrusions predicted with errors from ±10 to ±50 m.

EXPERIMENTAL DATA SET NO. 24: PHASE DISTRIBUTION IN BUBBLY FLOW

1992 ◽  
Vol 6 (1-4) ◽  
pp. 257-301 ◽  
Author(s):  
Akimi Serizawa ◽  
Isao Kataoka ◽  
Itaru Michiyoshi
Keyword(s):  
Experimental Data ◽  
Phase Distribution ◽  
Bubbly Flow ◽  
Data Set
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