Study of Metallurgy and Mechanical Property on Japanese Sword

2013 ◽  
Vol 738-739 ◽  
pp. 222-227 ◽  
Author(s):  
Muneo Yaso ◽  
Yoshihiro Minagi ◽  
Toshifumi Takaiwa ◽  
Kunichika Kubota ◽  
Tsuyoshi Kanaizumi ◽  
...  
Keyword(s):  
Grain Size ◽  
Cross Section ◽  
High Performance ◽  
Bending Strength ◽  
Lath Martensite ◽  
Bending Test ◽  
Sharp Edge ◽  
Tool Steels ◽  
The Difference ◽  
The Ideal

Japanese sword has finer grain size and lath martensite in the microstructure of sharp edge amazingly. Nowadays these structures are considered to be one of the ideal structure at which are greatly aimed to strengthen or improve toughness of steels. Though the carbon content of its sharp edge is 0.70 mass %, there are no lenticular martensite and no micocracking in that area. As a result of bending test by actual sword specimen, one sword was finally bent, the other sword was broken. However it is found the sharp edge in Japanese sword has such a large bending strength 2500, 4600MPa respectively as modern, high performance tool steels and the difference of crack propagation under bending depends on the microstructure distribution and the grain size in cross section of Japanese sword.

Study on the Performance of the New High-Strength Steel-Encased Concrete Composite Beam (SCCB)

2013 ◽  
Vol 756-759 ◽  
pp. 161-165
Author(s):  
Qi Yin Shi ◽  
Chao Liu ◽  
Li Lin Cao ◽  
Zhen Wang
Keyword(s):  
Cross Section ◽  
High Strength Steel ◽  
High Strength Concrete ◽  
Composite Beam ◽  
High Performance ◽  
Bending Strength ◽  
Theoretical Study ◽  
High Strength ◽  
Simply Supported ◽  
Ordinary Steel

On the basis of the theoretical study and application of ordinary steel-encased concrete composite beam, this paper will focus on a new high-strength steel-encased concrete composite beam, and mainly studies high-performance steel Q420 and Q460, as well as high-strength concrete C60 and C80. Besides, an experimental study of 5 simply-supported beams is made, and the load-deflection curves of new SCCB are analyzed. The calculation formula of load which changes with depth of section and bending strength of the cross section is also analyzed. It is suggested that the calculated results announced should be identical with the experimental results.

Analysis and Control of the Performance-Limiting Defects in HEM-Grown Silicon for Solar Cells

1995 ◽  
Vol 378 ◽  
Author(s):  
Chandra P. Khattak ◽  
Frederick Schmid ◽  
Michael Cudzinovic ◽  
Martha Symko ◽  
Bhushan L. Sopori
Keyword(s):  
Grain Size ◽  
Solar Cells ◽  
Heat Exchanger ◽  
Grain Boundaries ◽  
Cross Section ◽  
High Performance ◽  
Defect Density ◽  
Growth Features ◽  
And Control ◽  
Metallic Impurities

AbstractMulticrystalline silicon ingots of 55 cm × 55 cm cross section, 100 kg have been grown by the Heat Exchanger Method (HEM). Controlled growth features have been used to produce large grain size, vertically oriented grain boundaries, large areas of twins with low defect density and rejection of impurities to the top of the ingot. Ambient control has reduced C, N, and O concentration and minimized precipitates with no detectable metallic impurities. High performance solar cells have ben fabricated, and further improvements can be achieved by minimizing dislocation tangles and impurities in localized regions.

scholarly journals Utilization of Vacuum-Formed Plastic Membranes for the Production of Lightened HPC Panels

2019 ◽  
Vol 292 ◽  
pp. 236-241
Author(s):  
Jakub Řepka ◽  
Tomáš Vlach ◽  
Lenka Laiblová ◽  
Zuzana Jirkalová ◽  
Petr Hájek
Keyword(s):  
Cross Section ◽  
High Performance ◽  
Shear Failure ◽  
Bending Strength ◽  
High Performance Concrete ◽  
Full Cross Section ◽  
Ultimate Bending Strength ◽  
Cheap Alternative ◽  
Plastic Membrane ◽  
Concrete Matrix

This paper describes the utilization of vacuum-formed plastic membranes for the production of lightened panels made of high-performance concrete with technical textile reinforcement. The use of vacuum-formed plastic membranes is aimed to reduce the cost and increase the efficiency of production of concrete elements with highly profiled surface. Studded plastic membrane is cheap alternative to silicone or steel and while it provides slightly lower precision of manufacturing it surpasses especially the steel alternative in the terms of demoulding, since it has not sharp edges and can be easily bended.Second part of the article focuses on the limitations given by the lightening and the approach to reduce them while maintaining the reduction of material usage. The cross-section weakened by lightening in comparison to the un-lightened specimens leads to earlier development of cracks in concrete matrix and lower ultimate bending strength caused by shear failure of the lightened cross-section. The development of cracks in concrete matrix cannot be easily controlled while maintaining the same level of lightening but by addition of another layer of the reinforcement it is possible to achieve similar ultimate bending strength as in the case of elements with full cross-section and same thickness.

Microstructure and Magnetic Properties of Nd4.5Fe(76.5-x)B18.5Cu0.5Zrx Nanocomposite Permanent Magnetic Alloys

2007 ◽  
Vol 121-123 ◽  
pp. 1277-1280 ◽  
Author(s):  
Y. Qiao ◽  
Mao Cai Zhang ◽  
J. Zhu
Keyword(s):  
Grain Size ◽  
Magnetic Properties ◽  
Exchange Coupling ◽  
High Performance ◽  
Magnetic Phase ◽  
Soft Magnetic ◽  
Phase Component ◽  
Average Grain Size ◽  
The Difference ◽  
Microstructure And Magnetic Properties

Nanocomposite Nd2Fe14B/Fe3B magnetic materials with high performance have been obtained by crystallizing over-quenched ribbons. The effect of addition element of Cu and Zr on the phase component, microstructure and magnetic properties of Nd4.5Fe（76.5-x）B18.5Cu0.5Zrx (x= 0.4, 0.5, 1.5, 2.0, 3.0, 4.0) has been systematically investigated. The average grain size of Nd2Fe14B phase and Fe3B phase for the different compositions were calculated from X-day diffraction pattern, which are in accordance with TEM micrographs. For the Nd4.5Fe77B18.5 ribbons, the average grain size of Nd2Fe14B and Fe3B were 34.2 nm and 51.7 nm, and for the Nd4.5Fe76.3B18.5Cu0.5Zr0.4 ribbons, they were only 36.5 nm and 37.1 nm, respectively. It has been found that the additions of Cu and Zr cause the reduction of the difference of grain size between the hard magnetic phase and the soft magnetic phase, that increase the exchange coupling between them. Therefore, it would lead to the magnetic properties improvement. It has been determined that Nd4.5Fe76.3B18.5Cu0.5Zr0.4 was the optimal composition, and the optimal magnetic properties were: Br= 1.204 T, Hci= 271 kA/m, and (BH)max =111.2 kJ/m3.

Increase of bending strength and maximum deflection of concrete reinforced with CFRP strips

2011 ◽  
Vol 18 (1-2) ◽  
pp. 93-97
Author(s):  
Goichi Ben ◽  
Kazuhiro Sakata ◽  
Kazuma Saito
Keyword(s):  
High Performance ◽  
Bending Strength ◽  
Concrete Beams ◽  
Beam Theory ◽  
Design Criterion ◽  
Test Method ◽  
Bending Test ◽  
Plastic Behavior ◽  
Four Point Bending ◽  
Miyagi Prefecture

AbstractIn 1981, many detached houses collapsed owing to the earthquake which took place at the coast of Miyagi Prefecture in Japan, because ferroconcrete was not used as the base of most of the collapsed houses. Therefore, the earthquake-proof design criterion was revised and it was obliged to use ferroconcrete as the base of detached houses ever since. However, there are still more than 10 million detached houses using aged concrete as the base in Japan. In this paper, a reinforcement method for the aged concrete is demonstrated by using the high performance carbon fiber reinforced plastic (CFRP) strips. Three kinds of concrete beams reinforced with the CFRP strips with different vertical insert positions and different numbers of the CFRP strips were tested by a four point bending test method. In order to clarify the effects of CFRP strips, a concrete beam without reinforcement was also tested. The results of the experiment showed that the maximum deflections of the concrete beams reinforced with the CFRP strip were more than 100 times larger than those of the concrete beams without reinforcement. Although the concrete beams without the CFRP strips collapsed instantly, the concrete beams reinforced with the CFRP strips gradually failed, which were similar to the plastic behavior of metals. This result means that the residents can afford to escape safely from the houses in the event of possible earthquakes. The experimental results were compared with the analytical ones obtained from the composite beam theory and the failure criterion. Both results showed good agreement and the effectiveness of base concrete reinforced with CFRP strips was demonstrated.

scholarly journals Impact of media components from different suppliers on enterokinase productivity in Pichia pastoris

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ján Krahulec ◽  
Martin Šafránek
Keyword(s):  
Recombinant Proteins ◽  
Fermentation Process ◽  
High Impact ◽  
Production Level ◽  
Media Component ◽  
Component Supplier ◽  
The Media ◽  
The Difference ◽  
Optimisation Procedure ◽  
The Ideal

Abstract Background The aim of this study was to provide an information about the homogeneity on the level of enterokinase productivity in P. pastoris depending on different suppliers of the media components. Results In previous studies, we performed the optimisation process for the production of enterokinase by improving the fermentation process. Enterokinase is the ideal enzyme for removing fusion partners from target recombinant proteins. In this study, we focused our optimization efforts on the sources of cultivation media components. YPD media components were chosen as variables for these experiments. Several suppliers for particular components were combined and the optimisation procedure was performed in 24-well plates. Peptone had the highest impact on enterokinase production, where the difference between the best and worst results was threefold. The least effect on the production level was recorded for yeast extract with a 1.5 fold difference. The worst combination of media components had a activity of only 0.15 U/ml and the best combination had the activity of 0.88 U/ml, i.e., a 5.87 fold difference. A substantially higher impact on the production level of enterokinase was observed during fermentation in two selected media combinations, where the difference was almost 21-fold. Conclusions Results demonstrated in the present study show that the media components from different suppliers have high impact on enterokinase productivity and also provide the hypothesis that the optimization process should be multidimensional and for achieving best results it is important to perform massive process also in terms of the particular media component supplier .

scholarly journals Changes in Paleovegetation and Paleoclimate in China Since the Late Middle Pleistocene: A Case Study of the Dajiuhu Basin

2021 ◽  
Vol 13 (9) ◽  
pp. 4848
Author(s):  
Liwei Wu ◽  
Xinling Li ◽  
Qinghai Xu ◽  
Manyue Li ◽  
Qiufeng Zheng ◽  
...  
Keyword(s):  
Grain Size ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Asian Summer Monsoon ◽  
East Asian ◽  
Central China ◽  
Middle Pleistocene ◽  
Pollen Record ◽  
The Difference ◽  
Late Middle Pleistocene

The East Asian monsoon system is an important part of global atmospheric circulation; however, records of the East Asian monsoon from different regions exhibit different evolutionary rhythms. Here, we show a high-resolution record of grain size and pollen data from a lacustrine sediment core of Dajiuhu Lake in Shennongjia, Hubei Province, China, in order to reconstruct the paleovegetation and paleoeclimate evolution of the Dajiuhu Basin since the late Middle Pleistocene (~237.9 ka to the present). The results show that grain size and pollen record of the core DJH-2 are consistent with the δ18O record of stalagmites from Sanbao Cave in the same area, which is closely related to the changes of insolation at the precessional (~20-kyr) scale in the Northern Hemisphere. This is different from the records of the Asian summer monsoon recorded in the Loess Plateau of North China, which exhibited dominant 100-kyr change cyclicities. We suggest that the difference between paleoclimatic records from North and South China is closely related to the east–west-oriented mountain ranges of the Qinling Mountains in central China that blocked weakened East Asia summer monsoons across the mountains during glacial periods.

scholarly journals The Mechanical Properties and Damage Evolution of UHPC Reinforced with Glass Fibers and High-Performance Polypropylene Fibers

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2455
Author(s):  
Jiayuan He ◽  
Weizhen Chen ◽  
Boshan Zhang ◽  
Jiangjiang Yu ◽  
Hang Liu
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Damage Evolution ◽  
High Performance ◽  
High Performance Concrete ◽  
Glass Fibers ◽  
Ultra High Performance Concrete ◽  
Concrete Damaged Plasticity ◽  
The Difference ◽  
Experimental Values

Due to the sharp and corrosion-prone features of steel fibers, there is a demand for ultra-high-performance concrete (UHPC) reinforced with nonmetallic fibers. In this paper, glass fiber (GF) and the high-performance polypropylene (HPP) fiber were selected to prepare UHPC, and the effects of different fibers on the compressive, tensile and bending properties of UHPC were investigated, experimentally and numerically. Then, the damage evolution of UHPC was further studied numerically, adopting the concrete damaged plasticity (CDP) model. The difference between the simulation values and experimental values was within 5.0%, verifying the reliability of the numerical model. The results indicate that 2.0% fiber content in UHPC provides better mechanical properties. In addition, the glass fiber was more significant in strengthening the effect. Compared with HPP-UHPC, the compressive, tensile and flexural strength of GF-UHPC increased by about 20%, 30% and 40%, respectively. However, the flexural toughness indexes I5, I10 and I20 of HPP-UHPC were about 1.2, 2.0 and 3.8 times those of GF-UHPC, respectively, showing that the toughening effect of the HPP fiber is better.

scholarly journals Experimental Investigation on the Influence of Fiber Path Curvature on the Mechanical Properties of Composites

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2602
Author(s):  
Huaqiao Wang ◽  
Jihong Chen ◽  
Zhichao Fan ◽  
Jun Xiao ◽  
Xianfeng Wang
Keyword(s):  
Tensile Strength ◽  
Path Planning ◽  
Composite Laminates ◽  
Bending Strength ◽  
High Strength ◽  
Bending Test ◽  
Fiber Placement ◽  
Automated Fiber Placement ◽  
Fiber Path ◽  
Path Curvature

Automated fiber placement (AFP) has been widely used as an advanced manufacturing technology for large and complex composite parts and the trajectory planning of the laying path is the primary task of AFP technology. Proposed in this paper is an experimental study on the effect of several different path planning placements on the mechanical behavior of laminated materials. The prepreg selected for the experiment was high-strength toughened epoxy resin T300 carbon fiber prepreg UH3033-150. The composite laminates with variable angles were prepared by an eight-tow seven-axis linkage laying machine. After the curing process, the composite laminates were conducted by tensile and bending test separately. The test results show that there exists an optimal planning path among these for which the tensile strength of the laminated specimens decreases slightly by only 3.889%, while the bending strength increases greatly by 16.68%. It can be found that for the specific planning path placement, the bending strength of the composite laminates is significantly improved regardless of the little difference in tensile strength, which shows the importance of path planning and this may be used as a guideline for future AFP process.

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