A Modified Method of Arterial Elasticity Index Including Effects of Constraints From Surrounding Tissues

2009 ◽  
Author(s):  
Shinichiro Ota ◽  
Toshitaka Yasuda ◽  
Takashi Saito ◽  
Setsuo Takatani
Keyword(s):  
Natural Frequency ◽  
Estimation Method ◽  
Previous Method ◽  
Infinite Length ◽  
Arterial Elasticity ◽  
Thin Cylindrical Shell ◽  
Dynamic Constraints ◽  
Modified Method ◽  
Inner Pressure ◽  
Geometric Factors

Previously, we proposed an estimation method of arterial elasticity index (EM) independent of geometric factors such as the radius and wall thickness. Since the previous method was based on an equation of a motion that assumed a thin cylindrical model with infinite length, it is thus necessary to account for the effects of dynamic constraints from surrounding tissues. The purpose of this study is to propose a modified method for quantifying arterial elasticity index accounting for the effects of dynamic constraints. We describe the modified method by vibration analysis of a thin cylindrical shell using a natural frequency depending on boundary conditions. To examine the feasibility of the proposed method, we measured the inner pressure, radius and natural frequency of the mock-vessels with dynamic constraints. From these results, the elasticity index (EM) was derived independent of the effects of dynamic constraints. In summary, the proposed method enabled to derive elastic properties of arteries accounting for the effects of dynamic constraints in mock-vessels with both ends restricted.

The DMT Power Line Channel Sparse Bayesian Regression Estimation Based on Communication System

2014 ◽  
Vol 960-961 ◽  
pp. 1308-1311
Author(s):  
Yi Pei Huang ◽  
Ya Jun Han ◽  
Bao Fan Chen
Keyword(s):  
Channel Estimation ◽  
Bayesian Learning ◽  
Estimation Method ◽  
Power Line ◽  
Previous Method ◽  
Bayesian Regression ◽  
Estimation Model ◽  
Power Line Communications ◽  
Learning Framework ◽  
Performance Curves

This paper introduces the power line communications channel estimation method based on sparse Bayesian regression, it is through the use of Bayesian learning framework that provides a sparse model in the presence of noise accurate channel estimation model. Improved channel estimation using the power line for the system to consider the frequency domain equalization (FREQ) transmitter and receiver, the bit error rate and comparing the two methods for generating various channel estimation techniques, and (BER) performance curves simulation the results show that the performance of the method is better than the previous method of least squares technique.

Quantification of Arterial Stiffness Reduced Effect of Vessel Geometry

2008 ◽  
Author(s):  
Shinichiro Ota ◽  
Toshitaka Yasuda ◽  
Takashi Saito
Keyword(s):  
Mechanical Properties ◽  
Cylindrical Shell ◽  
Arterial Stiffness ◽  
Wall Thickness ◽  
Shell Theory ◽  
Dynamic Strain ◽  
Thin Cylindrical Shell ◽  
Inner Pressure ◽  
Latex Tube ◽  
Mechanical Factors

Arteriosclerosis is such as phenomena hardening of arteries, with thickening and loss of elasticity. Previous indexes include effect of geometric and mechanical factors as the radius, the wall thickness and mechanical properties of arteries. In this study, we proposed viscoelasticity indexes formulated by thin cylindrical shell theory estimated dynamic strain, and this index was independent of wall thickness and radius of arterial vessels. To confirm the validity of these indexes, we evaluated the parameters of viscoelasticity using the latex tube with different wall thickness of blood vessel model. We measured a radius of the latex tube and an inner pressure maintained by a pulsatile pump in a mock circuit filled with the water. Estimating the parameters of elasticity using these measured values, we concluded that a proposal index was independent of the wall thickness of the artery.

Natural Frequency Analysis of Tire Vibration Using a Thin Cylindrical Shell Model

2015 ◽  
Author(s):  
Masami Matsubara ◽  
Nobutaka Tsujiuchi ◽  
Takayuki Koizumi ◽  
Akihito Ito ◽  
Kensuke Bito
Keyword(s):  
Cylindrical Shell ◽  
Shell Model ◽  
Natural Frequency ◽  
Frequency Analysis ◽  
Thin Cylindrical Shell ◽  
Natural Frequency Analysis

scholarly journals Evaluation of Estimation Methods for Shear Fatigue Properties and Correlations with Uniaxial Fatigue Properties for Steels and Titanium Alloys

2018 ◽  
Vol 165 ◽  
pp. 16012 ◽  
Author(s):  
Shahriar Sharifimehr ◽  
Ali Fatemi
Keyword(s):  
Titanium Alloys ◽  
Inconel 718 ◽  
Fatigue Behavior ◽  
Estimation Method ◽  
Fatigue Tests ◽  
Estimation Methods ◽  
Fatigue Properties ◽  
Modified Method ◽  
Shear Fatigue ◽  
Von Mises

The goal of this study was to evaluate the accuracy of different methods in correlating uniaxial fatigue properties to shear fatigue properties, as well as finding a reliable estimation method which is able to predict the shear fatigue behavior of steels and titanium alloys from their monotonic properties. In order to do so, axial monotonic as well as axial and torsion fatigue tests were performed on two types of steel and a Ti-6Al-4V alloy. The results of these tests along with test results of 23 types of carbon steel, Inconel 718, and three types of titanium alloys commonly used in the industry were analyzed. It was found that von Mises and maximum principal strain criteria were able to effectively correlate uniaxial fatigue properties to shear fatigue properties for ductile and brittle behaving materials, respectively. Also, it was observed that for steels and Inconel 718 obtaining shear fatigue properties from uniaxial fatigue properties which are in turn calculated from Roessle-Fatemi estimation method resulted in reasonable estimations when compared to experimentally obtained uniaxial fatigue properties. Furthermore, a modification was made to the Roessle-Fatemi hardness method in order to adjust it to fatigue behavior of titanium alloys. The modified method, which was derived from uniaxial fatigue properties of titanium alloys with Brinell hardness between 240 and 353 proved to be accurate in predicting the shear fatigue behaviors.

scholarly journals Analysis of Toxic Metals in Aerosols from Devices Associated with Electronic Cigarette, or Vaping, Product Use Associated Lung Injury

Toxics ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 240
Author(s):  
Nathalie Gonzalez-Jimenez ◽  
Naudia Gray ◽  
R. Steven Pappas ◽  
Mary Halstead ◽  
Erica Lewis ◽  
...  
Keyword(s):  
Lung Injury ◽  
Metal Concentration ◽  
Method Validation ◽  
Toxic Metals ◽  
Toxic Elements ◽  
Previous Method ◽  
Research Gaps ◽  
Metal Concentrations ◽  
Modified Method ◽  
Low Concentrations

Research gaps exist in toxic metals characterization in e-cigarette, or vaping, products (EVPs) as these analytes typically have low concentrations and most standard aerosol trapping techniques have high metals background. An additional complication arises from differences in the EVP liquid formulations with nicotine products having polar properties and non-nicotine products often being non-polar. Differences in polar and non-polar matrices and the subsequent aerosol chemistries from various EVPs required modifications of our previously reported nicotine-based EVP aerosol method. Validation and application of the expanded method, suitable for both hydrophobic and hydrophilic aerosols, are reported here. The metals analyzed for this study were Al, Cr, Fe, Co, Ni, Cu, Cd, Sn, Ba, and Pb. The method limits of detection for the modified method ranged from 0.120 ng/10 puffs for Cd to 29.3 ng/10 puffs for Al and were higher than reported for the previous method. Results of the analyses for metals in aerosols obtained from 50 EVP products are reported. Cannabinoid based EVP aerosols were below reportable levels, except for one sample with 16.08 ng/10 puffs for Cu. Nicotine-based EVP results ranged from 6.72 ng/10 puffs for Pb to 203 ng/10 puffs for Sn. Results of the analyses for these metals showed that aerosols from only 5 of the 50 devices tested had detectable metal concentrations. Concentrations of toxic elements in the aerosols for nicotine-based EVP aerosol metal concentration ranges were consistent with previously published results of aerosol analyses from this class of devices.

Improved Method of Direct Measurement of the First-Order Mass Moments of Human Body Segments

2016 ◽  
Vol 698 ◽  
pp. 69-72
Author(s):  
Kosuke Suzuki ◽  
Kenta Nakaya ◽  
Akihiro Takita ◽  
Kazuhito Shimada ◽  
Yusaku Fujii
Keyword(s):  
Estimation Method ◽  
Previous Method ◽  
Previous Measurement ◽  
Scale Model ◽  
Measurement Time ◽  
Improved Method ◽  
First Order ◽  
Moment Estimation ◽  
Relative Standard ◽  
Mass Moment

The purpose of this research is to reduce the measurement time of the first-order mass moment estimation method proposed by us previously. In the previous method, the loads at the three points of the board are measured one by one using one piece of an expensive scale (model: GX-30KR, resolution: 0.1 g, price: 2,542 USD). The relative standard uncertainly of measurement using a rigid body is estimated to be 1.7% and the measurement time is approximately 10 minutes. In this research, three pieces of inexpensive scales (model: HD-660, resolution: 100 g, price: 17 USD) are used to reduce the measurement time. The relative standard uncertainly of measurement is estimated to be 1.9% and the measurement time is approximately 1 minute. In previous measurement, when changing the position of the scale, the position of the frame has been deviated slightly. However, in this method, this kind of error does not occur, since measurements of three points are simultaneously conducted.

scholarly journals Fractionation of Soil Organic Matter into Labile and Stable Fractions

Agronomy ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Marek Kopecký ◽  
Ladislav Kolář ◽  
Kristýna Perná ◽  
Radka Váchalová ◽  
Petr Mráz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Classical Method ◽  
Fulvic Acids ◽  
Exchange Capacity ◽  
Previous Method ◽  
New Method ◽  
Laboratory Equipment ◽  
Modified Method ◽  
Organic Fractions

The present study aims to test and evaluate the efficiency of a new modified method of organic matter evaluation. It allows the assessment of the quality and quantity of the primary soil organic matter and the stable organic fractions separately. The new method was tested in six soil samples of different localities in the Czech Republic. This method is based on observing reaction kinetics during the oxidation of soil organic matter and measuring the cation-exchange capacity of stable organic fractions. The results were compared with classical methods, which rely on the isolation of humic substances, determination of the content of humic acids and fulvic acids and their ratio CHA:CFA, quotient E4/6, and fractionation of soil organic matter according to resistance to oxidation. It turned out that the results of the new modified method are more sensitive in comparison with the results obtained by classical procedures. The linear regression demonstrated the dependence between the amounts of soil organic matter determined by the classical method compared with the modified method. Moreover, the new modified method was found to be faster and not demanding on laboratory equipment. The new method has been improved to be easily repeatable, and some shortcomings of the previous method were eliminated. Based on our results and other recent studies, the modified method may be recommended for the practical evaluation of soil organic matter conditions.

scholarly journals A MODIFICATION OF AN ESTIMATION METHOD OF THE NATURAL FREQUENCY OF A CUBE FORM MICRO SATELLITE

2018 ◽  
Vol 6 (7) ◽  
pp. 121-131
Author(s):  
Kei-Ichi Okuyama ◽  
Shigeru Hibino ◽  
Misuzu Matsuoka ◽  
Sidi A. Bendoukha ◽  
Aleksander Lidtke
Keyword(s):  
Mechanical Property ◽  
Aluminum Alloy ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Estimation Method ◽  
Longitudinal Direction ◽  
Practical Method ◽  
Lateral Direction ◽  
Satellite Structure ◽  
Vibration Tests

Micro satellites must survive severe mechanical conditions during their launch phase. One design requirement for rockets is the stiffness requirement, i.e. the natural frequencies requirement. In the early stages of satellite development, presumption of the natural frequency of a satellite may be difficult. The material used for the structure of many micro satellites is an aluminum alloy. The structure subsystem occupies a large portion of the satellite mass, and the elastic modulus of this aluminum alloy is larger than that of other subsystems. Therefore, the mechanical property of the aluminum alloy cannot be used to represent the mechanical property of the whole satellite.  The density of an actual satellite differs from the density of the aluminum alloy.  Therefore, when estimating the minimum natural frequency, the size and the elastic modules of an actual satellite structure must be used. When using an actual satellite structure, the estimated minimum natural frequencies of the lateral direction and the longitudinal direction during the ascent phase are in agreement with the measured values acquired by the vibration tests. In order to shorten a process of satellite development, this paper describes a practical method for estimating the natural frequency of a cube-shaped micro satellite This paper is a modified version of the previous paper [1] using new measurement results.

scholarly journals AN ESTIMATION METHOD OF THE NATURAL FREQUENCY OF A CUBE FORM MICRO SATELLITE

2018 ◽  
Vol 6 (3) ◽  
pp. 88-97
Author(s):  
Kei-ichi OKUYAMA ◽  
Shigeru HIBINO ◽  
Misuzu MATSUOKA ◽  
Aleksander LIDTKE
Keyword(s):  
Mechanical Property ◽  
Aluminum Alloy ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Estimation Method ◽  
Longitudinal Direction ◽  
Practical Method ◽  
Lateral Direction ◽  
Satellite Structure ◽  
Vibration Tests

Micro satellites must survive severe mechanical conditions during their launch phase. One design requirement for rockets is the stiffness requirement, i.e. the natural frequencies requirement. In the early stages of satellite development, presumption of the natural frequency of a satellite may be difficult. The material used for the structure of many micro satellites is an aluminum alloy. The structure subsystem occupies a large portion of the satellite mass, and the elastic modulus of this aluminum alloy is larger than that of other subsystems. Therefore, the mechanical property of the aluminum alloy cannot be used to represent the mechanical property of the whole satellite.  The density of an actual satellite differs from the density of the aluminum alloy.  Therefore, when estimating the minimum natural frequency, the size and the elastic modules of an actual satellite structure must be used.  When using an actual satellite structure, the estimated minimum natural frequencies of the lateral direction and the longitudinal direction during the ascent phase are in agreement with the measured values acquired by the vibration tests. In order to shorten a process of satellite development, this paper describes a practical method for estimating the natural frequency of a micro satellite.

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