Sensitive three-dimensional ultrasound assessment of carotid atherosclerosis by weighted average of local vessel wall and plaque thickness change

2017 ◽  
Vol 44 (10) ◽  
pp. 5280-5292 ◽  
Author(s):  
Jieyu Cheng ◽  
Eranga Ukwatta ◽  
Shadi Shavakh ◽  
Tommy W. S. Chow ◽  
Grace Parraga ◽  
...  
Keyword(s):  
Vessel Wall ◽  
Carotid Atherosclerosis ◽  
Three Dimensional ◽  
Weighted Average ◽  
Thickness Change ◽  
Ultrasound Assessment

scholarly journals Morphology and Mechanical Properties of Fossil Diatom Frustules from Genera of Ellerbeckia and Melosira

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1615
Author(s):  
Qiong Li ◽  
Jürgen Gluch ◽  
Zhongquan Liao ◽  
Juliane Posseckardt ◽  
André Clausner ◽  
...  
Keyword(s):  
Fracture Behavior ◽  
Three Dimensional ◽  
Mechanical Tests ◽  
Fracture Force ◽  
Thickness Change ◽  
X Ray ◽  
Transmission Electron ◽  
Percentage Concentration ◽  
Morphology Characterization

Fossil frustules of Ellerbeckia and Melosira were studied using laboratory-based nano X-ray tomography (nano-XCT), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). Three-dimensional (3D) morphology characterization using nondestructive nano-XCT reveals the continuous connection of fultoportulae, tube processes and protrusions. The study confirms that Ellerbeckia is different from Melosira. Both genera reveal heavily silicified frustules with valve faces linking together and forming cylindrical chains. For this cylindrical architecture of both genera, valve face thickness, mantle wall thickness and copulae thickness change with the cylindrical diameter. Furthermore, EDS reveals that these fossil frustules contain Si and O only, with no other elements in the percentage concentration range. Nanopores with a diameter of approximately 15 nm were detected inside the biosilica of both genera using TEM. In situ micromechanical experiments with uniaxial loading were carried out within the nano-XCT on these fossil frustules to determine the maximal loading force under compression and to describe the fracture behavior. The fracture force of both genera is correlated to the dimension of the fossil frustules. The results from in situ mechanical tests show that the crack initiation starts either at very thin features or at linking structures of the frustules.

Three-Dimensional Stress Distribution in Arteries

1983 ◽  
Vol 105 (3) ◽  
pp. 268-274 ◽  
Author(s):  
C. J. Chuong ◽  
Y. C. Fung
Keyword(s):  
Experimental Data ◽  
Stress Distribution ◽  
Vessel Wall ◽  
Strain Energy ◽  
Arterial Wall ◽  
Three Dimensional ◽  
Strain Energy Function ◽  
Exponential Form ◽  
Strain Relationship ◽  
Longitudinal Stretch

A three-dimensional stress-strain relationship derived from a strain energy function of the exponential form is proposed for the arterial wall. The material constants are identified from experimental data on rabbit arteries subjected to inflation and longitudinal stretch in the physiological range. The objectives are: 1) to show that such a procedure is feasible and practical, and 2) to call attention to the very large variations in stresses and strains across the vessel wall under the assumptions that the tissue is incompressible and stress-free when all external load is removed.

Ultrasound Assessment of Atherosclerotic Vessel Wall Changes

2000 ◽  
Vol 35 (12) ◽  
pp. 699-706 ◽  
Author(s):  
ALEXANDR ŠRÁMEK ◽  
JOHANNES G. BOSCH ◽  
JOHAN H. C. REIBER ◽  
JACOBUS A. VAN OOSTAYEN ◽  
FRITS R. ROSENDAAL
Keyword(s):  
Vessel Wall ◽  
Ultrasound Assessment

Three-dimensional numerical simulation of the filling stage in resin infusion process

2016 ◽  
Vol 50 (29) ◽  
pp. 4171-4186 ◽  
Author(s):  
Bo Yang ◽  
Qian Tang ◽  
Shilong Wang ◽  
Tianguo Jin ◽  
Fengyang Bi
Keyword(s):  
Viscoelastic Model ◽  
Three Dimensional ◽  
Mass Conservation ◽  
Great Difficulty ◽  
Resin Flow ◽  
Resin Infusion ◽  
Thickness Change ◽  
Geometry Model ◽  
Filling Stage ◽  
Dimensional Simulation

Resin infusion (RI) process has been widely used for manufacturing composite parts. The variation of preform thickness brings great difficulty to the three-dimensional simulation of the filling stage. To accurately simulate the preform thickness change and resin flow during resin infusion, precise preform compaction models and dynamically changing geometry models need to be adopted. At present, resin flow is usually considered as two-dimensional and simple compaction models are employed to simplify the simulation, which degrades the prediction accuracy seriously. In this paper, general equations to describe the resin flow in the changing thickness cavity are developed, and the viscoelastic model is adopted which can fully express the dynamic characteristics of the preform compaction. To avoid solving the coupled resin flow/preform deformation equations directly, the volume of fluid method and the dynamic mesh model are employed to implement the tracking of the flow front and updating of cavity geometry model. The resin storage and release induced by porosity variations are adjusted by a master-slave element method to ensure mass conservation. Two simulation examples are carried out to demonstrate the capability of the above approach. The applicability of the approach on arbitrary complex domains and sequential injection strategy is also verified.

Weighted average geodesic distance of Vicsek network in three-dimensional space

2021 ◽  
pp. 2150077
Author(s):  
Yan Liu ◽  
Meifeng Dai ◽  
Yuanyuan Guo
Keyword(s):  
Dimensional Space ◽  
Geodesic Distance ◽  
Three Dimensional ◽  
Weighted Average ◽  
Weight Vector ◽  
Natural Generalization ◽  
The Self ◽  
Self Similarity ◽  
Similar Measure ◽  
Three Dimensional Space

Fractal generally has self-similarity. Using the self-similarity of fractal, we can obtain some important theories about complex networks. In this paper, we concern the Vicsek fractal in three-dimensional space, which provides a natural generalization of Vicsek fractal. Concretely, the Vicsek fractal in three-dimensional space is obtained by repeatedly removing equilateral cubes from an initial equilateral cube of unit side length, at each stage each remaining cube is divided into [Formula: see text] smaller cubes of which [Formula: see text] are kept and the rest discarded, where [Formula: see text] is odd. In addition, we obtain the skeleton network of the Vicsek fractal in three-dimensional space. Then we focus on weighted average geodesic distance of the Vicsek fractal in three-dimensional space. Take [Formula: see text] as an example, we define a similar measure on the Vicsek fractal in three-dimensional space by weight vector and calculate the weighted average geodesic distance. At the same time, asymptotic formula of weighted average geodesic distance on the skeleton network is also obtained. Finally, the general formula of weighted average geodesic distance should be applicable to the models when [Formula: see text], the base of a power, is odd.

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