Visualization of a pillar-shaped fiber bundle in a model needle-punched nonwoven fabric using X-ray micro-computed tomography

2016 ◽  
Vol 87 (11) ◽  
pp. 1387-1393 ◽  
Author(s):  
Tatsuya Ishikawa ◽  
KyoungHou Kim ◽  
Yutaka Ohkoshi

In the needle-punching process, the barbs of a needle catch fibers and orient them along the thickness direction of the fabric. The oriented fibers form a pillar-shaped fiber bundle, which acts as a bonding point of the fabric. The structure of the pillar-shaped fiber bundle thus governs the mechanical properties of needle-punched nonwoven fabric, and both are largely affected by the needle-punching conditions. However, the three-dimensional structure of pillar-shaped fiber bundles and their development under different needle-punching conditions have not been revealed. In the present study, we visualized the three-dimensional structure of a pillar-shaped fiber bundle in needle-punched nonwoven fabric, employing X-ray micro-computed tomography (XCT) on the basis of the difference in the X-ray absorption coefficient between polyethylene terephthalate (PET) and polyethylene fibers. For a material density ratio of less than 1.4 and PET fibers having a diameter of 40 µm, the pillar-shaped bundles of PET fibers were visualized by erasing 20-µm polyethylene fibers in XCT images. Furthermore, we investigated the effects of the penetration depth of the needle on the development of pillar-shaped fiber bundles. The number of fibers constituting a pillar largely increased at a penetration depth of 19.0 mm, and pillars protruded from the bottom surface of the fabric and formed a stitch structure. The XCT applied in this study is thus effective in analyzing the structure of pillar-shaped fiber bundles quantitatively without affecting the structure of the nonwoven fabric.

Author(s):  
Sterling P. Newberry

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.


1988 ◽  
Vol 16 (6) ◽  
pp. 949-953 ◽  
Author(s):  
JOHN P. PRIESTLE ◽  
HANS-PETER SCHÄR ◽  
MARKUS G. GRÜTTER

Summary The three-dimensional structure of human recombinant interleukin-1β has been determined at 0.24 nm resolution by X-ray crystallographic techniques. The partially refined model has a crystallographic R-factor of just under 19%. The structure is composed of 12 β-strands forming a complex network of hydrogen bonds. The core of the structure can best be described as a tetrahedron whose edges are each formed by two antiparallel β-strands. The interior of this structure is filled with hydrophobic side-chains. There is a 3-fold repeat in the folding of the polypeptide chain. Although this folding pattern suggests gene triplication, no significant internal sequence homology between topologically corresponding residues exists. The folding topology of interleukin-1β is very similar to that described by A. D. McLachlan [(1979) J. Mol. Biol. 133, 557–563] for soybean trypsin inhibitor.


Author(s):  
Cerrone Cabanos ◽  
Hiroyuki Urabe ◽  
Taro Masuda ◽  
Mary Rose Tandang-Silvas ◽  
Shigeru Utsumi ◽  
...  

Peanuts contain some of the most potent food allergens known to date. Ara h 1 is one of the three major peanut allergens. As a first step towards three-dimensional structure elucidation, recombinant Ara h 1 core region was cloned, expressed inEscherichia coliand purified to homogeneity. Crystals were obtained using 0.1 Msodium citrate pH 5.6, 0.1 MNaCl, 15% PEG 400 as precipitant. The crystals diffracted to 2.25 Å resolution using synchrotron radiation and belonged to the monoclinic space groupC2, with unit-cell parametersa= 156.521,b= 88.991,c= 158.971 Å, β = 107.144°. Data were collected at the BL-38B1 station of SPring-8 (Hyogo, Japan).


Materia Japan ◽  
2007 ◽  
Vol 46 (12) ◽  
pp. 823-823
Author(s):  
Seiji Kawado ◽  
Toshinori Taishi ◽  
Satoshi Iida ◽  
Yoshifumi Suzuki ◽  
Yoshinori Chikaura ◽  
...  

2004 ◽  
Vol 693 (1-3) ◽  
pp. 199-203 ◽  
Author(s):  
Quan-Zheng Zhang ◽  
Can-Zhong Lu ◽  
Wen-Bin Yang ◽  
Shu-Mei Chen ◽  
Ya-Qin Yu

2004 ◽  
Vol 573 (2) ◽  
pp. 191-203 ◽  
Author(s):  
P. Geissbühler ◽  
P. Fenter ◽  
E. DiMasi ◽  
G. Srajer ◽  
L.B. Sorensen ◽  
...  

2011 ◽  
Vol 44 (3) ◽  
pp. 526-531 ◽  
Author(s):  
David Allen ◽  
Jochen Wittge ◽  
Jennifer Stopford ◽  
Andreas Danilewsky ◽  
Patrick McNally

In the semiconductor industry, wafer handling introduces micro-cracks at the wafer edge and the causal relationship of these cracks to wafer breakage is a difficult task. By way of understanding the wafer breakage process, a series of nano-indents were introduced both into 20 × 20 mm (100) wafer pieces and into whole wafers as a means of introducing controlled strain. Visualization of the three-dimensional structure of crystal defects has been demonstrated. The silicon samples were then treated by various thermal anneal processes to initiate the formation of dislocation loops around the indents. This article reports the three-dimensional X-ray diffraction imaging and visualization of the structure of these dislocations. A series of X-ray section topographs of both the indents and the dislocation loops were taken at the ANKA Synchrotron, Karlsruhe, Germany. The topographs were recorded on a CCD system combined with a high-resolution scintillator crystal and were measured by repeated cycles of exposure and sample translation along a direction perpendicular to the beam. The resulting images were then rendered into three dimensions utilizing open-source three-dimensional medical tomography algorithms that show the dislocation loops formed. Furthermore this technique allows for the production of a video (avi) file showing the rotation of the rendered topographs around any defined axis. The software also has the capability of splitting the image along a segmentation line and viewing the internal structure of the strain fields.


2021 ◽  
Author(s):  
Xianke Wang ◽  
Lin Chen ◽  
Bin Huang ◽  
Jin Yuan ◽  
Lili Shang ◽  
...  

Abstract Bamboo is a natural fiber composite with layered structure. Millions of years of evolution have endowed bamboo with the most effective structure in nature. The ingenious microstructure provides bamboo with excellent mechanical properties. Bamboo culm is composed of the cortex, a middle layer, and a pith ring. The cortex refers to the area starting from the periphery of the culm wall to the vascular bundles. The present study obtained the two-dimensional microstructure of bamboo cortex cells by optical microscopy and characterized the three-dimensional structure through high-resolution X-ray microtomography (µCT). Based on the analysis, the bamboo cortex cells were classified into four layers: epidermis layer, hypodermis layer, transitional layer, and parenchyma layer. The average pore volume of the bamboo cortex was about 1.54×10-6 mm3, the porosity was 36.1%, and the relative density was 0.639. The epidermis layer, hypodermis layer, transition layer, and parenchyma layer cells had a cell cavity volume of 917.81 µm3, 714.22 µm3, 1258.19 µm3, and 3117.65 µm3, respectively, an average length3d (L) of 19.38 µm, 25.84 µm, 26.46 µm, and 34.88 µm, respectively, an average breadth3d (W) of 14.11 µm, 9.44 µm, 15.22 µm, and 16.6 µm, respectively, and sphericity of 0.85, 0.76, 0.75, and 0.78, respectively. Studies on bamboo anatomical structure, especially three-dimensional digital characterization, will enrich the bamboo microstructure database. Besides, the three-dimensional structure of the bamboo cortex revealed in this study can provide a reference for optimizing composite material hierarchy and biomimetic design.


Sign in / Sign up

Export Citation Format

Share Document