Quantitative Estimation of the Amount of Fibrosis in the Rat Liver Using Fractal Dimension of the Shape of Power Spectrum

A sampling procedure and calculations are described by which electron micrographs of cytoplasmic structures may be quantitatively analyzed. The relative areas occupied by formed bodies and by the "membrane space," the remainder of the cytoplasm, are evaluated. A method for making a measurement of the quantity of endoplasmic reticulum or other membrane profiles is described. The technic and results are illustrated with normal rat liver cells.

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Experimental study on the effects of fractures on elastic wave propagation in synthetic layered rocks

Geophysics ◽

10.1190/geo2015-0661.1 ◽

2016 ◽

Vol 81 (4) ◽

pp. D441-D451 ◽

Cited By ~ 9

Author(s):

Tianyang Li ◽

Ruihe Wang ◽

Zizhen Wang ◽

Yuzhong Wang

Keyword(s):

Wave Propagation ◽

Fractal Dimension ◽

Power Spectrum ◽

Elastic Wave ◽

Power Law ◽

Layered Media ◽

Physical Models ◽

P Wave ◽

Fracture Density ◽

S Wave

Fractures greatly increase the difficulty of oil and gas exploration and development in reservoirs consisting of interlayered carbonates and shales and increase the uncertainty of highly efficient development. The presence of fractures or layered media is also widely known to affect the elastic properties of rocks. The combined effects of fractures and layered media are still unknown. We have investigated the effects of fracture structure on wave propagation in interlayered carbonate and shale rocks using physical models based on wave theory and the similarity principle. We have designed and built two sets of layered physical models with randomly embedded predesigned vertically aligned fractures according to the control variate principle. We have measured the P- and S-wave velocities and attenuation and analyzed the effects of fracture porosity and aspect ratio (AR) on velocity, attenuation, and power spectral dimension of the P- and S-waves. The experimental results indicated that under conditions of low porosity ([Formula: see text]), Han’s empirical velocity-porosity relations and Wang’s attenuation-porosity relation combined with Wyllie’s time-average model are a good prediction for layered physical models with randomly embedded fractures. When the porosity is constant, the effect of different ARs on elastic wave properties can be described by a power law function. We have calculated the power spectrum fractal dimension [Formula: see text] of the transmitted signal in the frequency domain, which can supplement the S-wave splitting method for estimating the degree of anisotropy. The simple power law relation between the power spectrum fractal dimension of the P-waveform and fracture density suggests the possible use of P-waves for discriminating fracture density. The high precision and low error of this processing method give new ideas for rock anisotropy evaluation and fracture density prediction when only P-wave data are available.

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Ultrasonic imaging by fractal dimension of power spectrum shape

10.1109/ultsym.1990.171608 ◽

2002 ◽

Author(s):

T. Kikuchi ◽

S. Kiryu ◽

S. Sato

Keyword(s):

Fractal Dimension ◽

Power Spectrum ◽

Ultrasonic Imaging ◽

Spectrum Shape

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Fractal Analysis of Event Related Potential

Journal of Robotics and Mechatronics ◽

10.20965/jrm.1993.p0198 ◽

1993 ◽

Vol 5 (2) ◽

pp. 198-201

Author(s):

Hideto Ide ◽

◽

Shinjiro Yagi

Keyword(s):

Time Series ◽

Fractal Dimension ◽

Power Spectrum ◽

Observational Data ◽

Fractal Analysis ◽

Event Related Potential

We have tried to apply fractal analysis to time series which have 1/f power spectrum. Before carrying out any analysis, we expand the idea of fractal to time series. We examine the fractal dimension of time series to simulate the Brawnian function. We apply fractal analysis to observational data of event related potential (ERP) and compare averaging results with those based on fractal analysis.

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Quantitative estimation of transcellular and paracellular pathways of biliary sucrose in isolated perfused rat liver

Biochemical Journal ◽

10.1042/bj2410635 ◽

1987 ◽

Vol 241 (3) ◽

pp. 635-640 ◽

Cited By ~ 26

Author(s):

H Jaeschke ◽

H Krell ◽

E Pfaff

Keyword(s):

Rat Liver ◽

Half Life ◽

Quantitative Estimation ◽

Sucrose Concentration ◽

Equilibrium Concentration ◽

Paracellular Pathway ◽

Slow Phase ◽

Isolated Perfused Rat Liver ◽

Perfused Rat Liver ◽

Biliary Clearance

A method was developed to estimate the relative contributions of paracellular and transcellular pathways to the total biliary clearance of sucrose in isolated perfused rat liver. When livers were perfused with a sucrose-containing medium (1 mM), biliary sucrose concentration reached an equilibrium of 165 +/- 27 microM within 10 min, without further significant change up to 40 min. After removal of sucrose from the perfusate, the decrease of the sucrose concentration in bile was found to obey biphasic first-order kinetics, showing a rapid initial decrease (half-life 3.3 +/- 0.5 min) and then a slower decrease (half-life 29.4 +/- 5.7 min). Both phases of decrease were further characterized. Pretreating rats with the cholestatic agents alpha-naphthyl isothiocyanate (ANIT), oestradiol valerate (OV) and colchicine increased the biliary equilibrium concentration and decreased the half-life of the fast phase of the biliary sucrose elimination. The slow phase was unaffected in the livers of ANIT- and OV-treated rats. The slow phase of biliary sucrose efflux was sensitive to colchicine treatment. A close correlation was observed between the slow-phase fraction of the biliary sucrose and the corresponding sucrose content of the liver. By quantitative analysis of the efflux kinetics the relative contribution of the paracellular pathway to the biliary clearance of sucrose was estimated to be 83 +/- 2% in control livers, which increased to about 90% in livers of pretreated animals. These results are important in view of the use of sucrose in evaluating the paracellular-pathway permeability in intra- and extra-hepatic cholestasis.

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Sea State Characterization Using Experimental One-Dimensional Radar Signatures and Fractal Techniques

Elektronika ir Elektrotechnika ◽

10.5755/j02.eie.28906 ◽

2021 ◽

Vol 27 (3) ◽

pp. 71-77

Author(s):

Georgios Pouraimis ◽

Apostolos Kotopoulis ◽

Basil Massinas ◽

Panayiotis Frangos

Keyword(s):

Fractal Dimension ◽

Power Spectrum ◽

Main Idea ◽

Power Spectrum Density ◽

Synthetic Aperture ◽

Sea State ◽

One Dimensional ◽

Range Profile ◽

Spectrum Density ◽

Novel Method

This paper presents a novel method of sea state characterization by using four criteria, which are applied to normalized experimental Synthetic Aperture Radar (SAR) one–dimensional signatures (range profiles), provided to our research group by SET 215 Working Group on “SAR radar techniques”. These criteria are the “Fractal Dimension”, “Fractal Length”, “Variance σ2”, and “Power Spectrum Density - Least Squares”. The “Fractal Dimension” and “Fractal Length” criteria, which appear to be the most important out of the four criteria, use the “blanket” technique to provide sea state characterization from SAR radar range profiles. It is based on the calculation of the area of a “blanket”, corresponding to the range profile under examination, and then on the calculation of the corresponding “Fractal Dimension” and “Fractal Length” of the range profile. The main idea concerning this proposed technique is the fact that normalized SAR radar range profiles, corresponding to different sea states, produce different values of “Fractal Dimension” and “Fractal Length” for all angles of incidence examined here. As a result, a sea state characterization technique for two different sea states (turbulent and calm sea) is presented in this paper.

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