scholarly journals Incorporating a Ferrous Polymer Target into Elastomeric Liners for Socket Fit Sensing in Prosthesis Users

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5620
Author(s):  
Ryan V. Carter ◽  
Brian G. Larsen ◽  
Jake B. McLean ◽  
Joseph L. Garbini ◽  
Joan E. Sanders

Liner-to-socket distance measurement using inductive sensing may be an effective means to continuously monitor socket fit in people using trans-tibial prostheses. A practical limitation, however, is a means to incorporate a thin uniform-thickness layer of conductive or magnetically permeable target material into the wide range of prosthetic liner products that people with limb amputation commonly use. In this paper, a method is presented whereby a 0.50-mm thickness ferrous polymer made from a SEEPS polymer and iron powder that is formed adjacent to a 0.25-mm thick non-ferrous layer of SEEPS polymer is assembled between two sheets of elastic fabric material. Bench testing showed that the fabrication procedure achieved a root-mean-square error in the thickness of this construct of 58 μm, helping to create a consistent calibration result over the entire surface. The original fabric backing of an off-the-shelf prosthetic liner was removed and replaced with the developed construct. When worn in the shoe of an able-bodied participant for 7.5 h per day for 28 days, the sensor well maintained the shape of its calibration curve at the start of wear, but a distance offset (shifting of the y-intercept) was introduced that increased during the initial approximately 12 days of wear. When the distance offset was corrected, for the primary distance range of clinical interest for this application (0.00–5.00 mm), the sensor maintained its calibration within 4.4%. Before being used in clinical application for liner-to-socket distance monitoring, new ferrous liners may need to be pre-worn so as to achieve a consistent distance reference.

Author(s):  
Matthew Rendle

This book provides the first detailed account of the role of revolutionary justice in the early Soviet state. Law has often been dismissed by historians as either unimportant after the October Revolution amid the violence and chaos of civil war or even, in the absence of written codes and independent judges, little more than another means of violence. This is particularly true of the most revolutionary aspect of the new justice system, revolutionary tribunals—courts inspired by the French Revolution and established to target counter-revolutionary enemies. This book paints a more complex picture. The Bolsheviks invested a great deal of effort and scarce resources into building an extensive system of tribunals that spread across the country, including into the military and the transport network. At their peak, hundreds of tribunals heard hundreds of thousands of cases every year. Not all ended in harsh sentences: some were dismissed through lack of evidence; others given a wide range of sentences; others still suspended sentences; and instances of early release and amnesty were common. This book, therefore, argues that law played a distinct and multifaceted role for the Bolsheviks. Tribunals stood at the intersection between law and violence, offering various advantages to the Bolsheviks, not least strengthening state control, providing a more effective means of educating the population on counter-revolution, and enabling a more flexible approach to the state’s enemies. All of this adds to our understanding of the early Soviet state and, ultimately, of how the Bolsheviks held on to power.


Author(s):  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirzai

Erosion equations are usually obtained from experiments by impacting solid particles entrained in a gas or liquid on a target material. The erosion equations are utilized in CFD (Computational Fluid Dynamics) models to predict erosion damage caused by solid particle impingements. Many erosion equations are provided in terms of an erosion ratio. By definition, the erosion ratio is the mass loss of target material divided by the mass of impacting particles. The mass of impacting particles is the summation of (particle mass × number of impacts) of each particle. In erosion experiments conducted to determine erosion equations, some particles may impact the target wall many times and some other particles may not impact the target at all. Therefore, the experimental data may not reflect the actual erosion ratio because the mass of the sand that is used to run the experiments is assumed to be the mass of the impacting particles. CFD and particle trajectory simulations are applied in the present work to study effects of multiple impacts on developing erosion ratio equations. The erosion equation as well as the CFD-based erosion modeling procedure is validated against a variety of experimental data. The results show that the effect of multiple impacts is negligible in air cases. In water cases, however, this effect needs to be accounted for especially for small particles. This makes it impractical to develop erosion ratio equations from experimental data obtained for tests with sand in water or dense gases. Many factors affecting erosion damage are accounted for in various erosion equations. In addition to some well-studied parameters such as particle impacting speed and impacting angle, particle size also plays a significant role in the erosion process. An average particle size is usually used in analyzing experimental data or estimating erosion damage cases of practical interest. In petroleum production applications, however, the size of sand particles that are entrained in produced fluids can vary over a fairly broad range. CFD simulations are also performed to study the effect of particle size distribution. In CFD simulations, particle sizes are normally distributed with the mean equaling the average size of interest and the standard deviation varying over a wide range. Based on CFD simulations, an equation is developed and can be applied to account for the effect of the particle size distribution on erosion prediction for gases and liquids.


Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. T243-T255 ◽  
Author(s):  
James W. D. Hobro ◽  
Chris H. Chapman ◽  
Johan O. A. Robertsson

We present a new method for correcting the amplitudes of arrivals in an acoustic finite-difference simulation for elastic effects. In this method, we selectively compute an estimate of the error incurred when the acoustic wave equation is used to approximate the behavior of the elastic wave equation. This error estimate is used to generate an effective source field in a second acoustic simulation. The result of this second simulation is then applied as a correction to the original acoustic simulation. The overall cost is approximately twice that of an acoustic simulation but substantially less than the cost of an elastic simulation. Because both simulations are acoustic, no S-waves are generated, so dispersed converted waves are avoided. We tested the characteristics of the method on a simple synthetic model designed to simulate propagation through a strong acoustic impedance contrast representative of sedimentary geology. It corrected amplitudes to high accuracy for reflected arrivals over a wide range of incidence angles. We also evaluated results from simulations on more complex models that demonstrated that the method was applicable in realistic sedimentary models containing a wide range of seismic contrasts. However, its accuracy was reduced for wide-angle reflections from very high impedance contrasts such as a shallow top-salt interface. We examined the influence of modeling at coarse grid resolutions, in which converted S-waves in the equivalent elastic simulation are dispersed. These results provide some validation for the accuracy of the method when applied using finite-difference grids designed for acoustic modeling. The method appears to offer a cost-effective means of modeling elastic amplitudes for P-wave arrivals in a useful range of velocity models. It has several potential applications in imaging and inversion.


2006 ◽  
Vol 129 (1) ◽  
pp. 58-65 ◽  
Author(s):  
B. Scott Kessler ◽  
A. Sherif El-Gizawy ◽  
Douglas E. Smith

The accuracy of a finite element model for design and analysis of a metal forging operation is limited by the incorporated material model’s ability to predict deformation behavior over a wide range of operating conditions. Current rheological models prove deficient in several respects due to the difficulty in establishing complicated relations between many parameters. More recently, artificial neural networks (ANN) have been suggested as an effective means to overcome these difficulties. To this end, a robust ANN with the ability to determine flow stresses based on strain, strain rate, and temperature is developed and linked with finite element code. Comparisons of this novel method with conventional means are carried out to demonstrate the advantages of this approach.


2003 ◽  
Vol 62 (2) ◽  
pp. 393-397 ◽  
Author(s):  
John R. Arthur

There are now concerns that dietary Se intake is inadequate for the population in the UK and parts of Europe. Many different methods can be proposed to deal with this problem. Experience from Finland suggests that the addition of Se to fertiliser is a safe and effective means of increasing the intake of the micronutrient in the human population. However, careful consideration needs to be given to the potential consequences of increasing Se intake. It is important to understand the biochemical and physiological changes that may occur with any increase in Se intake within the UK population. Se is an essential component of at least twenty functional proteins within mammals. These proteins are essential for a range of metabolic functions, including antioxidant activity, thyroid hormone synthesis and immune function. Thus, any increase in Se intake has the potential to influence in a wide range of factors that may impinge on the incidence of chronic disease. Treatment of soil with Se-supplemented fertiliser will certainly increase total Se in food products derived from areas where this treatment is in place. Consumption of such foods will increase Se status in many populations where the existing intake does not meet requirements. If the increases in Se intake are not toxic the overall consequences have the potential to be beneficial.


1990 ◽  
Vol 191 ◽  
Author(s):  
Akiharu Morimoto ◽  
Shigeru Otsubo ◽  
Tatsuo Shimizu ◽  
Toshiharu Minamikawa ◽  
Yasuto Yonezawa ◽  
...  

ABSTRACTPb(Zr0.52Ti0. 48)O3 (PZT) films were prepared on r-plane sapphire substrates by the laser ablation method utilizing ArF excimer laser in O2 or N2O environment. The composition of the films deposited in O2 environment was found to be fairly close to the composition of the target material for a wide range of substrate temperatures, 400 – 750 °c. Increasing the laser fluence (the laser power density) for the ablation enhances the formation of the perovskite structure rather than the pyrochlore one. Use of N2O ambient gas instead of O2 gas enhances the formation of the perovskite structure of PZT films. Furthermore, it was found that a laser irradiation on the growing film surface during deposition enhances the formation of the perovskite structure.


2021 ◽  
Vol 869 (1) ◽  
pp. 012007
Author(s):  
A Yuslan ◽  
N Nasir ◽  
H Suhaimi ◽  
A Arshad ◽  
N W Rasdi

Abstract Copepods with a wide range of sizes, species, and nutritional compositions are preferred as live food for rearing of Betta splendens larvae. This research focuses on evaluating the efficiency of copepod enrichment diets in improving the coloration and feeding rate of B. splendens. Copepod were enriched with Chlorella sp. (T1), capsicum (T2), mixed vegetable (carrot + spinach), (T3), yeast (T4) and rice bran (T5) in 24 hours prior the feeding tests. As a result, proximate analysis of enriched-copepods showed that T1 (70.88±0.41) has highest protein content and T5 (22.01±0.59) has the highest lipid content. The specific growth rate and survival rate of B. splendens was highest in the treatment T1 (2.56±0.07%; 91.11±1.92%) and followed closely by T3 (2.49±0.51%; 85.55±8.39%). Feeding rate, T3 (70.08±3.88%) presented highest rate compared to other treatments. The different enrichment diets used were significantly impact the coloration test on body of L* value (P=0.001, P<0.05), T3 (66.11±3.60) appeared darker in color in contrast to others. As for a* value, the coloration was not impacted with the use of different enrichment on copepods (P=0.158, P>0.05) was detected for T1 (2.84±0.73) that gave a redder shade than other treatments did. T3 (2.40±0.30) exerted a more yellowish shade than the rest for b* value with a significant difference (P=0.015, P<0.05). The current study demonstrates that, rice bran, capsicum and mixed vegetable enrichment (carrot and spinach) have the potential to be an effective means of increasing B. splendens coloring and feeding rate. This potential diet can be further used as a substitution to artificial foods in producing sustainable culture of ornamental fish in the aquaculture industry.


2000 ◽  
Author(s):  
Lin Ma ◽  
Erik K. Antonsson

Abstract A method for automated mask-layout and process synthesis for MEMS is presented. The synthesis problem is approached by use of a genetic algorithm. For a given desired device shape, and several fabrication process choices, this synthesis method will produce one or more mask-layouts and associated fabrication process sequences (which when used can generate shapes close to the desired one). Given complicated device shapes and wide range of fabrication process possibilities, the designer may encounter difficulty producing the right mask-layout and fabrication procedure by experience and trial and error. An automated synthesis tool like this will be helpful to the designer by increasing the efficiency and accuracy of the design of MEMS devices.


1992 ◽  
Vol 6 (3) ◽  
pp. 626-634 ◽  
Author(s):  
Ganesh M. Kishore ◽  
Stephen R. Padgette ◽  
Robert T. Fraley

Weed management is an integral part of agriculture; weeds lower both productivity and quality of agricultural products. A combination of mechanical, chemical, biological, and cultural methods is expected to deliver a sustainable weed management program for the next two decades. While chemical methods offer the most cost effective means of weed management, crop selectivity has hampered the use of the best chemicals for weed management. Recent progress in gene technology has facilitated the introduction and expression of genes to confer a wide range of traits to crop plants. Application of this technology has resulted in the development of crop plant genotypes that are resistant to a specific herbicide. This article describes the progress that has been made by our group toward the introduction of glyphosate tolerance to crop plants. Glyphosate [N-(phosphonomethyl)glycine] kills plants due to inhibition of the biosynthesis of aromatic compounds via the shikimate pathway. Our approach for introduction of glyphosate tolerance is based on insertion and expression in plants of a gene encoding a glyphosate-tolerant 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, a key enzyme of the shikimate pathway. The wild type enzyme present in plants is susceptible to inhibition glyphosate; variants of EPSP synthase have been produced that are less susceptible to inhibition by glyphosate. Expression of genes encoding these variants has been shown to confer glyphosate tolerance to plants. The degree of glyphosate tolerance is related to the tolerance characteristics of the EPSP synthase variant, its substrate activity, targeting to the plastid, and the level of expression of the variant gene. The tissue specificity of expression of the variant EPSP synthase has also been shown to be critical since glyphosate is a systemic herbicide and is translocated to many growing points within the plant. Our studies on glyphosate tolerance have substantially enhanced our understanding of the mode-of-action of glyphosate, the shikimate pathway, and protein sorting within plant cells, as well as developmental and tissue specific expression of genes in plants. Commercial use of glyphosate tolerance technology is expected to affect positively, the weed management arsenal available to the farmers, the sustainability of farm land and groundwater, and promote the use of a “soft” herbicide.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1567 ◽  
Author(s):  
Taojie Lu ◽  
Ruina Xu ◽  
Bo Zhou ◽  
Yichuan Wang ◽  
Fuzhen Zhang ◽  
...  

Nanoporous materials have a wide range of applications in clean energy and environmental research. The permeability of nanoporous materials is low, which affects the fluid transport behavior inside the nanopores and thus also affects the performance of technologies based on such materials. For example, during the development of shale gas resources, the permeability of the shale matrix is normally lower than 10−3 mD and has an important influence on rock parameters. It is challenging to measure small pressure changes accurately under high pressure. Although the pressure decay method provides an effective means for the measurement of low permeability, most apparatuses and experiments have difficulty measuring permeability in high pressure conditions over 1.38 MPa. Here, we propose an improved experimental method for the measurement of low permeability. To overcome the challenge of measuring small changes in pressure at high pressure, a pressure difference sensor is used. By improving the constant temperature accuracy and reducing the helium leakage rate, we measure shale matrix permeabilities ranging from 0.05 to 2 nD at pore pressures of up to 8 MPa, with good repeatability and sample mass irrelevance. The results show that porosity, pore pressure, and moisture conditions influence the matrix permeability. The permeability of moist shale is lower than that of dry shale, since water blocks some of the nanopores.


Sign in / Sign up

Export Citation Format

Share Document