Mechanism of Large Elastic Modulus of Bone

2011 ◽  
Vol 689 ◽  
pp. 390-394 ◽  
Author(s):  
Bin Chen ◽  
Da Gang Yin ◽  
Ji Luo ◽  
Quan Yuan ◽  
Jing Hong Fan
Keyword(s):  
Electron Microscope ◽  
Elastic Modulus ◽  
Scanning Electron Microscope ◽  
Large Volume ◽  
Volume Fraction ◽  
Thin Fiber ◽  
Sem Observation ◽  
Large Volume Fraction ◽  
Composite Mechanics ◽  
Scanning Electron

Scanning electron microscope (SEM) observation shows that fibula bone is a kind of bioceramic composite consisting of hydroxyapatite layers and protein matters. The hydroxyapatite layers are further composed of hydroxyapatite sheets. The observation also shows that the hydroxyapatite sheets possess quite large volume fraction and also have very long and thin fiber shape. The mechanism of the large volume fraction of the hydroxyapatite sheets to ensure the larger elastic modulus of the bone was investigated based on the model of the bone composite and the theory of the composite mechanics. The investigated result reveals that the large volume fraction of the hydroxyapatite sheets endows the bone with large elastic modulus.

RESEARCH OF THE NANOMETER HELICOIDAL LAYUP OF RUFESCENS SHELL

2005 ◽  
Vol 19 (01n03) ◽  
pp. 577-579
Author(s):  
BIN CHEN ◽  
XIANG-HE PENG ◽  
JING-HONG FAN ◽  
WAN-LU WANG
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Ceramic Composite ◽  
Organic Matrix ◽  
Nanometer Scale ◽  
Pullout Force ◽  
Sem Observation ◽  
Scanning Electron

A scanning electron microscope (SEM) observation on a Rufescens shell shows that the shell is a bio-ceramic composite consisting of aragonite sheets with nanometer scale and organic matrix. These nano-aragonite sheets are arranged in the shell in the form of helicoidal layup. The reason of the excellent fracture toughness of the shell is analyzed based on the maximal pullout force of the helicoidal layup of the aragonite sheets in the shell.

Helicoidal-Rounded-Hole Microstructure of Mature Shankbone

2011 ◽  
Vol 460-461 ◽  
pp. 652-655
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Pullout Force ◽  
Sem Observation ◽  
Collagen Protein ◽  
Scanning Electron

Scanning electron microscope (SEM) observation on a mature shankbone shows that the bone is a kind of bioceramic composite consisting of hydroxyapatite sheets and collagen protein matrix. The observation also shows that there are many holes in the bone and that the hydroxyapatite sheets near by these holes helicoidally round these holes forming a kind of helicoidally-rounded-hole microstructure (HRHM). The maximum pullout force of the HRHM is investigated and compared with that of non-helicoidally-rounded-hole microstructure (NHRHM). It shows that the HRHM could markedly increase the maximum pullout force of the hydroxyapatite sheets compared to the NHRHM and therefore enhance the fracture toughness of the bone.

Correlation between Solidified Microstructure Evolution and Undercooling of Au-12 Wt.%Ge Eutectic Alloy

2020 ◽  
Vol 993 ◽  
pp. 53-59
Author(s):  
Zhen Yong Zhu ◽  
Kai Xiong ◽  
Jun Jie He ◽  
Shun Meng Zhang ◽  
Si Yong Xu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Microstructure Evolution ◽  
Eutectic Alloy ◽  
Volume Fraction ◽  
Experimental Results ◽  
Solidification Structure ◽  
Forming Process ◽  
Maximum Undercooling ◽  
Scanning Electron

Highly undercooled solidification experiments were carried out by melt purification combined with cyclic superheating method on Au-12 wt.%Ge eutectic alloy. The solidification structures of Au-12 wt.%Ge eutectic alloy under different undercoolings were also analyzed by using the scanning electron microscope (SEM). The experimental results revealed that the maximum undercooling could reach up to 102 K. The microstructure analysis showed that the coarse bulk eutectic existed in the solidification structure when the undercooling was less than 34 K. When the undercooling was larger than 34 K and less than 56 K, the solidification structure transformed into cellular eutectic. The coarse primary (α-Au) phase precipitated from the undercooled alloy melt when the undercooling was larger than 56 K. The volume fraction of the primary (α-Au) phase gradually increased with the increase of undercooling. In this paper, a method to regulate the solidification structure of Au-12 wt.%Ge eutectic alloy is proposed, which provides a new way to improve the solidification structure and has important guiding significance for the processing and forming process of Au-12 wt.%Ge eutectic alloy.

Description of larvae of Japanese Macronychini (Coleoptera: Elmidae: Elminae)

Zootaxa ◽  
2020 ◽  
Vol 4859 (2) ◽  
pp. 195-227
Author(s):  
MASAKAZU HAYASHI ◽  
YUUKI KAMITE
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sem Observation ◽  
First Time ◽  
Scanning Electron

Larvae of 15 species of Macronychini, subfamily Elminae, belonging to the genera Sinonychus Jäch & Boukal, Paramacronychus Nomura, Zaitzeviaria Nomura, Zaitzevia Champion, and Urumaelmis Satô were described based on scanning electron microscope (SEM) observation. Larvae of eleven of these species, S. tsujunensis Yoshitomi & Nakajima, Zaitzeviaria gotoi (Nomura), Zaitzeviaria brevis (Nomura), Zaitzeviaria kuriharai Kamite, Ogata & Satô, Zaitzevia elongata Nomura, Zaitzevia aritai Satô, Zaitzevia yaeyamana Satô, Zaitzevia awana (Kôno), Zaitzevia nitida Nomura, Zaitzevia tsushimana Nomura, and U. uenoi (Nomura) are described for the first time. 

Mechanism of High Fracture Strength of Bone

2011 ◽  
Vol 685 ◽  
pp. 379-383
Author(s):  
Bin Chen ◽  
Da Gang Yin ◽  
Quan Yuan ◽  
Ji Luo ◽  
Jing Hong Fan
Keyword(s):  
Electron Microscope ◽  
Fracture Mechanics ◽  
Scanning Electron Microscope ◽  
Fracture Strength ◽  
Nanometer Scale ◽  
High Fracture ◽  
Microstructural Characteristics ◽  
Thin Fiber ◽  
Femur Bone ◽  
Scanning Electron

Scanning electron microscope (SEM) observation showed that femur bone is a kind of bioceramic composite consisting of hydroxyapatite layers and protein matters. The hydroxyapatite layers are further composed of hydroxyapatite fiber sheets. The observation also showed that the hydroxyapatite fiber sheets possess very thin fiber shape. The thickness of the hydroxyapatite fiber sheets is within nanometer scale. The mechanism of the high fracture strength of the bone was investigated based on the microstructural characteristics of the hydroxyapatite fiber sheets and the theory of fracture mechanics. The result reveals that the thin fiber shape of the hydroxyapatite fiber sheets endows the bone with high fracture strength.

scholarly journals Image Processing Tool Quantifying Auto-Tempered Carbides in As-Quenched Low Carbon Martensitic Steels

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 171 ◽  
Author(s):  
Shashank Ramesh Babu ◽  
Thomas Paul Davis ◽  
Tim Haas ◽  
Antti Jarvenpää ◽  
Jukka Kömi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Image Processing ◽  
Image Segmentation ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Volume Fraction ◽  
Low Carbon ◽  
Martensitic Steels ◽  
Color Map ◽  
Scanning Electron

As-quenched low-carbon martensitic steels (<0.2 wt.% C) contain auto-tempered carbides. Auto-tempering improves the work hardening and upper-shelf impact energy; however, an efficient characterization method to determine the degree of auto-tempering has not been available. This paper demonstrates an efficient image processing tool that calculates the relative auto-tempered carbide fraction by analyzing scanning electron microscope micrographs. By the process of image segmentation, the qualitative volume fraction of auto-tempered carbides can be determined, and an associated color map produced, which distinguished the levels of auto-tempering. This image processing tool could become useful for the optimization of new low-carbon steel’s mechanical properties.

scholarly journals Possibility of Scanning Electron Microscope Observation and Energy Dispersive X-Ray Analysis in Microscale Region of Insulating Samples Using Diluted Ionic Liquid

2012 ◽  
Vol 18 (2) ◽  
pp. 365-370 ◽  
Author(s):  
Susumu Imashuku ◽  
Tetsuo Kawakami ◽  
Long Ze ◽  
Jun Kawai
Keyword(s):  
Ionic Liquid ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive ◽  
Light Elements ◽  
Standard Samples ◽  
X Ray ◽  
Spectrometry Analysis ◽  
Sem Observation ◽  
Scanning Electron

AbstractThe possibility of scanning electron microscope (SEM) observation and energy dispersive X-ray (EDX) spectrometry analysis in microscale regions of insulating samples using diluted ionic liquid was investigated. It is possible to obtain clear secondary electron images of insulating samples such as a rock and mineral at 5,000 times magnification by dropping 10 μL of 1 wt% of 1-ethyl-3-methylimidazolium acetate (EMI-CH3COO) diluted with ethanol onto the samples. We also obtained EDX spectra of the samples in microscale regions (∼5 μm2) without overlapping EDX spectra of other minerals with different composition. It might be possible to perform quantitative analysis of the samples if a method that does not need standard samples is applied or an X-ray detector sensitive for light elements was attached. The method of dropping 1 wt% EMI-CH3COO diluted with ethanol onto insulating samples is useful for SEM observation, EDX analysis in microscale regions, and the preservation of scarce rock and mineral samples because ionic liquid can be easily removed with acetone.

The Influence of Holmium on the Microstructure and Hardness of Mg-Nd-Gd-Zn-Zr Alloys

2017 ◽  
Vol 740 ◽  
pp. 48-53 ◽  
Author(s):  
Rosli Ahmad ◽  
N.R. Shahizan ◽  
M.B.A. Asmael ◽  
Ashraf M.M. Elaswad
Keyword(s):  
Grain Size ◽  
Rare Earth ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Vickers Hardness ◽  
Volume Fraction ◽  
Hardness Test ◽  
Vickers Hardness Test ◽  
Scanning Electron ◽  
Zr Alloys

The influence of holmium on the microstructure and hardness of Mg-Nd-Gd-Zn-Zr alloys were investigated. Conventional casting methods are used to produce the alloys. All the results were characterized by optical microscopy, scanning electron microscope (SEM) and the Vickers hardness test to highlight the influence of holmium addition. The addition of 2.0 wt.% holmium leads to the combination of rare earth elements which formed Mg-Zn-Nd-Ho phase. The results have shown the addition of Ho improved the microstructure and hardness of Mg-Nd-Gd-Zn-Zr alloys. By adding grain size of 2.0 wt.% holmium had reduced by 18.43%, while the volume fraction increased by 7.34%. The Vickers hardness value improved 6.18% due to the grain refine and volume fraction precipitates. The 2.0 wt.% holmium addition showed a positive result in microstructure and hardness value.

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