scholarly journals Influence of Bleaching on Plastic Flow Deformation of Electron-Beam Irradiated Wood

2021 ◽  
Vol 70 (7) ◽  
pp. 541-546
Author(s):  
Hideaki SUGINO ◽  
Soichi TANAKA ◽  
Yuga KASAMATSU ◽  
Satoko OKUBAYASHI ◽  
Masako SEKI ◽  
...  

2020 ◽  
Vol 66 (2) ◽  
pp. 59-66 ◽  
Author(s):  
Hideaki Sugino ◽  
Soichi Tanaka ◽  
Yuga Kasamatsu ◽  
Satoko Okubayashi ◽  
Masako Seki ◽  
...  


2020 ◽  
Vol 66 (1) ◽  
Author(s):  
Kazushi Nakai ◽  
Soichi Tanaka ◽  
Kozo Kanayama ◽  
Tsuyoshi Yoshimura

Abstract African blackwood (ABW: Dalbergia melanoxylon) is a valuable tree in Tanzanian local community forests, and heartwood has been mainly utilized as an irreplaceable material in musical instruments, e.g., clarinet, oboe and piccolo. Since its use is generally for the production of musical instruments only, most of the harvested volume is wasted due to defects that would affect the quality of final products. Wood flow forming can transform bulk woods into materials in temperature/pressure-controlled mold via plastic flow deformation. The main object of this study was to evaluate the deformation characteristics of ABW heartwood in developing the potential of wasted ABW parts in terms of the effective material use. The deformation characteristics of heartwood were examined by free compression tests. Specimens were compressed along the radial direction at 120 °C, and air-dried heartwood was dramatically deformed in the tangential direction. The plastic flow deformation of ABW was amplified by the presence of both extractives and moisture. In particular, the ethanol/benzene (1:2, v/v) soluble extractives in heartwood may have contributed to flow deformation. The results of the dynamic mechanical analysis showed that the air-dried heartwood exhibited softening in a temperature range over 50 °C. The ethanol/benzene-soluble extractives contributed to the softening behavior. The clarified deformation characteristics of ABW can contribute to more efficient material use of local forests.



2015 ◽  
Vol 21 (S3) ◽  
pp. 1015-1016 ◽  
Author(s):  
Sanjit Bhowmick ◽  
Douglas Stauffer ◽  
Ryan Major ◽  
Oden Warren ◽  
S. A. Syed Asif


2021 ◽  
Author(s):  
Masako Seki ◽  
Mitsuru Abe ◽  
Tsunehisa Miki ◽  
Masakazu Nishida

Abstract In this study, we clarified the influence of lignin in wood on its plastic flow deformation due to shear sliding of wood cells. Wood samples were subjected to delignification, where the lignin structure gradually changed, and characterized for their chemical and physicochemical properties, and deformability by free compression testing. The delignified wood deformed by efficient stretching and maintained its cell structures at a lower pressure compared to the untreated wood. The deformability was evaluated from two viewpoints: the initial resistance to plastic flow and final stretchability. The deformability of the delignified and untreated wood increased with increasing compressive temperature, even though the changes in molecular motility associated with the glass transition of lignin contributed minimally to the improvement in deformability. In the early stages of delignification, the molecular mass of lignin in the compound middle lamella decreased, which reduced the initial resistance to plastic flow. However, during the early stages of delignification, the stretchability of delignified wood was scarcely affected by changes in lignin. As the amount of lignin was further reduced and delignification proceeded in the vicinity of the polysaccharides, the stretchability significantly improved. The correlation between chemical and physicochemical properties and plastic flow deformability presented in this paper will be helpful for low-energy and highly productive forming of solid-state wood.



1985 ◽  
Vol 107 (4) ◽  
pp. 444-451 ◽  
Author(s):  
Shinobu Kato ◽  
Etsuo Marui ◽  
Kiyoo Tachi

The frictional characteristic is examined with reference to a model considering the interference effect of plastic flow (deformation) in soft metal film, when a two-protuberance indentor is slid on a surface covered by electroplated soft metal film. The result is compared with that of a single-protuberance indentor. The coefficient of friction in a two-protuberance indentor, where the interference effect exists, is lower than in a single-protuberance indentor, where the interference effect does not. This fact can well be explained with the configuration of plastic flow line on protuberances described by deforming soft metal film, and the corresponding contact pressure distribution between protuberances and a surface.



Nanoscale ◽  
2014 ◽  
Vol 6 (3) ◽  
pp. 1499-1507 ◽  
Author(s):  
Xianfang Zhu ◽  
Jiangbin Su ◽  
Yan Wu ◽  
Lianzhou Wang ◽  
Zhanguo Wang


Author(s):  
G. G. Shaw

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.



Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.



Author(s):  
L. D. Jackel

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.



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