scholarly journals Micro- and Nano-Scales Three-Dimensional Characterisation of Softwood

2021 ◽  
Vol 7 (12) ◽  
pp. 263
Author(s):  
Alessandra Patera ◽  
Anne Bonnin ◽  
Rajmund Mokso
Keyword(s):  
Mechanical Response ◽  
Three Dimensional ◽  
Deep Understanding ◽  
Swelling Behaviour ◽  
Multi Scale ◽  
Non Invasive ◽  
X Ray Imaging ◽  
New Findings ◽  
Bordered Pits ◽  
Paul Scherrer

Understanding the mechanical response of cellular biological materials to environmental stimuli is of fundamental importance from an engineering perspective in composites. To provide a deep understanding of their behaviour, an exhaustive analytical and experimental protocol is required. Attention is focused on softwood but the approach can be applied to a range of cellular materials. This work presents a new non-invasive multi-scale approach for the investigation of the hygro-mechanical behaviour of softwood. At the TOMCAT beamline of the Paul Scherrer Institute, in Switzerland, the swelling behaviour of softwood was probed at the cellular and sub-cellular scales by means of 3D high-resolution phase-contrast X-ray imaging. At the cellular scale, new findings in the anisotropic and reversible swelling behaviour of softwood and in the origin of swelling hysteresis of porous materials are explained from a mechanical perspective. However, the mechanical and moisture properties of wood highly depend on sub-cellular features of the wood cell wall, such as bordered pits, yielding local deformations during a full hygroscopic loading protocol.

Multi-Scale Finite-Element Analysis as a Base for a 3D Computerized Virtual Biopsy System

2008 ◽  
Author(s):  
Lev Podshivalov ◽  
Anath Fischer ◽  
Pinhas Z. Bar-Yoseph
Keyword(s):  
Bone Structure ◽  
Domain Decomposition Method ◽  
Three Dimensional ◽  
Local Solution ◽  
Fe Method ◽  
Element Analysis ◽  
Multi Scale ◽  
Non Invasive ◽  
And Behavior ◽  
Trabecular Bone Tissue

This paper proposes a novel multi-scale approach for three-dimensional non-invasive analysis of 3d bone models reconstructed from μCT/μMRI images. The feasibility of the proposed method is demonstrated on 2D models representing a simple 2D trabecular bone tissue structure. First, a fundamental domain decomposition method is applied to solve these models. Then, a numerical zoom technique is utilized for local solution enhancement. The proposed new multi-scale FE method has the potential to provide new insights into bone structure and behavior as a component of a computerized virtual biopsy system.

Quantifying the Spatial Variation of Lower-Limb Soft Tissue Artefact During Functional Activity Using MR Imaging and X-Ray Fluoroscopy

2009 ◽  
Author(s):  
Massoud Akbarshahi ◽  
Justin W. Fernandez ◽  
Anthony Schache ◽  
Richard Baker ◽  
Scott Banks ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Lower Limb ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
X Ray ◽  
Non Invasive ◽  
3D Motion Analysis ◽  
X Ray Imaging ◽  
Tissue Interface ◽  
Soft Tissue Artifact

Non-rigid movement of the soft tissue interface between skin-mounted markers and the underlying bones, also known as soft tissue artifact (STA), poses a major limitation to the non-invasive estimation of joint kinematics using three-dimensional (3D) motion analysis systems. Thorough knowledge of the nature of this non-rigid behavior is essential for development of compensation algorithms to enhance the accuracy of these systems. The studies in the literature aimed at quantifying STA have implemented invasive measurement methods such as bone pins [1] and external fixator devices [2], or have used subjects with pathological conditions [3]. In the present study, we integrated Magnetic Resonance (MR) and X-ray imaging techniques to evaluate the non-rigid behavior of the lower-limb soft tissue of healthy adults for a number of different functional tasks.

Multi-scale modelling of the damage behavior for 3D woven composites with variant structure

2021 ◽  
pp. 152808372110238
Author(s):  
Hua Zhong ◽  
Shuzi Yang
Keyword(s):  
Mechanical Response ◽  
Damage Model ◽  
Three Dimensional ◽  
Tensile Modulus ◽  
Woven Composites ◽  
Scale Model ◽  
Multi Scale ◽  
Macro Scale ◽  
3D Woven Composites ◽  
Variant Structure

In the process of fabricating a three-dimensional (3 D) woven perform, the variant structures introduced during adding and reducing tows, lead to changes of local tow orientation and woven pattern, which affects the mechanical response of 3 D woven composite. In this study, specimens with variant structure were manufactured by adding and reducing tow techniques, and representative unit cells of normal and variant structure were established by topological method. A multi-scale damage model was proposed to analyze the damage behaviors and predict the strength of 3 D woven composites with the user subroutine UMAT of ABAQUS/Standard. The results show that the variation of tensile modulus and strength between the experimental and simulation value were less than 4%. In addition, it is proved that the damage propagation of the macro-scale model with variant structure can be successfully captured.

scholarly journals Biomechanics of subcellular structures by non-invasive Brillouin microscopy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Giuseppe Antonacci ◽  
Sietse Braakman
Keyword(s):  
Mechanical Response ◽  
Single Cells ◽  
Three Dimensional ◽  
Biomechanical Properties ◽  
Cell Stiffness ◽  
Non Invasive ◽  
Cellular Biomechanics ◽  
Latrunculin A ◽  
Longitudinal Elastic Modulus ◽  
A Cell

Abstract Cellular biomechanics play a pivotal role in the pathophysiology of several diseases. Unfortunately, current methods to measure biomechanical properties are invasive and mostly limited to the surface of a cell. As a result, the mechanical behaviour of subcellular structures and organelles remains poorly characterised. Here, we show three-dimensional biomechanical images of single cells obtained with non-invasive, non-destructive Brillouin microscopy with an unprecedented spatial resolution. Our results quantify the longitudinal elastic modulus of subcellular structures. In particular, we found the nucleoli to be stiffer than both the nuclear envelope (p < 0.0001) and the surrounding cytoplasm (p < 0.0001). Moreover, we demonstrate the mechanical response of cells to Latrunculin-A, a drug that reduces cell stiffness by preventing cytoskeletal assembly. Our technique can therefore generate valuable insights into cellular biomechanics and its role in pathophysiology.

X-ray microtomography

1988 ◽  
Vol 46 ◽  
pp. 998-999
Author(s):  
H.W. Deckman ◽  
B.F. Flannery ◽  
J.H. Dunsmuir ◽  
K.D' Amico
Keyword(s):  
Computed Tomography ◽  
Internal Structure ◽  
Imaging Technique ◽  
Three Dimensional ◽  
Tissue Structure ◽  
Individual Element ◽  
X Ray ◽  
Non Invasive ◽  
Panoramic Imaging ◽  
Three Dimensional Images

We have developed a new X-ray microscope which produces complete three dimensional images of samples. The microscope operates by performing X-ray tomography with unprecedented resolution. Tomography is a non-invasive imaging technique that creates maps of the internal structure of samples from measurement of the attenuation of penetrating radiation. As conventionally practiced in medical Computed Tomography (CT), radiologists produce maps of bone and tissue structure in several planar sections that reveal features with 1mm resolution and 1% contrast. Microtomography extends the capability of CT in several ways. First, the resolution which approaches one micron, is one thousand times higher than that of the medical CT. Second, our approach acquires and analyses the data in a panoramic imaging format that directly produces three-dimensional maps in a series of contiguous stacked planes. Typical maps available today consist of three hundred planar sections each containing 512x512 pixels. Finally, and perhaps of most import scientifically, microtomography using a synchrotron X-ray source, allows us to generate maps of individual element.

Construction of plastic contact deformation maps on ceramics: a case study on aluminum nitride

1996 ◽  
Vol 54 ◽  
pp. 636-637
Author(s):  
D. L. Callahan
Keyword(s):  
Plastic Deformation ◽  
Aluminum Nitride ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Bright Field Image ◽  
Perfectly Plastic ◽  
Contrast Analysis ◽  
Deformation Patterns

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.

Three-dimensional speckle-tracking echocardiography – a further step in the non-invasive three-dimensional cardiac imaging

2012 ◽  
Vol 153 (40) ◽  
pp. 1570-1577 ◽  
Author(s):  
Attila Nemes ◽  
Anita Kalapos ◽  
Péter Domsik ◽  
Tamás Forster
Keyword(s):  
Cardiac Imaging ◽  
Speckle Tracking ◽  
Speckle Tracking Echocardiography ◽  
Three Dimensional ◽  
Myocardial Mechanics ◽  
Non Invasive ◽  
Imaging Methodology ◽  
Invasive Evaluation

Three-dimensional speckle-tracking echocardiography is a new cardiac imaging methodology, which allows three-dimensional non-invasive evaluation of the myocardial mechanics. The aim of this review is to present this new tool emphasizing its diagnostic potentials and demonstrating its limitations, as well. Orv. Hetil., 2012, 153, 1570–1577.

Three-dimensional Reconstruction of Microscopic Image Based on Multi-ST Algorithm

2020 ◽  
Vol 64 (2) ◽  
pp. 20506-1-20506-7
Author(s):  
Min Zhu ◽  
Rongfu Zhang ◽  
Pei Ma ◽  
Xuedian Zhang ◽  
Qi Guo
Keyword(s):  
3D Reconstruction ◽  
Three Dimensional ◽  
Scale Model ◽  
Microscopic Image ◽  
Multi Scale ◽  
Gaussian Pyramid ◽  
Cost Aggregation ◽  
Dimensional Reconstruction ◽  
Image Pairs ◽  
Accurate Matching

Abstract Three-dimensional (3D) reconstruction is extensively used in microscopic applications. Reducing excessive error points and achieving accurate matching of weak texture regions have been the classical challenges for 3D microscopic vision. A Multi-ST algorithm was proposed to improve matching accuracy. The process is performed in two main stages: scaled microscopic images and regularized cost aggregation. First, microscopic image pairs with different scales were extracted according to the Gaussian pyramid criterion. Second, a novel cost aggregation approach based on the regularized multi-scale model was implemented into all scales to obtain the final cost. To evaluate the performances of the proposed Multi-ST algorithm and compare different algorithms, seven groups of images from the Middlebury dataset and four groups of experimental images obtained by a binocular microscopic system were analyzed. Disparity maps and reconstruction maps generated by the proposed approach contained more information and fewer outliers or artifacts. Furthermore, 3D reconstruction of the plug gauges using the Multi-ST algorithm showed that the error was less than 0.025 mm.

Electrical Capacitance Volume Tomography (ECVT) for industrial and medical applications-An Overview

2015 ◽  
Vol 11 (1) ◽  
pp. 2897-2908
Author(s):  
Mohammed S.Aljohani
Keyword(s):  
Imaging Technique ◽  
Three Dimensional ◽  
Biological Processes ◽  
Electrical Capacitance ◽  
Image Reconstruction Techniques ◽  
Phase Dynamics ◽  
Non Invasive ◽  
Electrical Capacitance Volume Tomography ◽  
And Performance ◽  
Optimization And Performance

Tomography is a non-invasive, non-intrusive imaging technique allowing the visualization of phase dynamics in industrial and biological processes. This article reviews progress in Electrical Capacitance Volume Tomography (ECVT). ECVT is a direct 3D visualizing technique, unlike three-dimensional imaging, which is based on stacking 2D images to obtain an interpolated 3D image. ECVT has recently matured for real time, non-invasive 3-D monitoring of processes involving materials with strong contrast in dielectric permittivity. In this article, ECVT sensor design, optimization and performance of various sensors seen in literature are summarized. Qualitative Analysis of ECVT image reconstruction techniques has also been presented.

scholarly journals Non-invasive three-dimensional thickness analysis of oral epithelium based on optical coherence tomography—development and diagnostic performance

Heliyon ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. e06645
Author(s):  
Charlotte Theresa Trebing ◽  
Sinan Sen ◽  
Stefan Rues ◽  
Christopher Herpel ◽  
Maria Schöllhorn ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diagnostic Performance ◽  
Three Dimensional ◽  
Oral Epithelium ◽  
Optical Coherence ◽  
Non Invasive
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