Mechanism of High Modulus and Strength of Unio Douglasiae Shell

2011 ◽  
Vol 467-469 ◽  
pp. 571-574
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan ◽  
Jing Hong Fan
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Fracture Strength ◽  
High Strength ◽  
High Density ◽  
Nanometer Scale ◽  
High Modulus ◽  
Sem Observation ◽  
Griffith Criterion ◽  
Scanning Electron

Scanning electron microscope (SEM) observation shows that the shell of a Unio douglasiae is a kind of bioceramic composite consisting of laminated aragonite and organic materials. The aragonite layers further consist of thin and long aragonite fibers. The aragonite fibers possess high density in the shell and their diameter is within nanometer scale. The mechanism of the high modulus and high strength of the shell were investigated based on the observed nanometer structure of the aragonite fibers and the rule of mixtures Young’s modulus as well as the Griffith criterion. It reveals that the high density and the nanometer scale of the aragonite fibers endow the shell with high modulus and fracture strength.

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.

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.

Using the scanning electron microscope for failure analysis of high density magnetic media

1987 ◽  
Vol 45 ◽  
pp. 392-393
Author(s):  
Evelyn R. Ackerman ◽  
Gary D. Burnett
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Analysis ◽  
High Density ◽  
Magnetic Media ◽  
Specific Data ◽  
Retrieval Systems ◽  
Operating Environments ◽  
The Media ◽  
Scanning Electron

Advancements in state of the art high density Head/Disk retrieval systems has increased the demand for sophisticated failure analysis methods. From 1968 to 1974 the emphasis was on the number of tracks per inch. (TPI) ranging from 100 to 400 as summarized in Table 1. This emphasis shifted with the increase in densities to include the number of bits per inch (BPI). A bit is formed by magnetizing the Fe203 particles of the media in one direction and allowing magnetic heads to recognize specific data patterns. From 1977 to 1986 the tracks per inch increased from 470 to 1400 corresponding to an increase from 6300 to 10,800 bits per inch respectively. Due to the reduction in the bit and track sizes, build and operating environments of systems have become critical factors in media reliability.Using the Ferrofluid pattern developing technique, the scanning electron microscope can be a valuable diagnostic tool in the examination of failure sites on disks.

Micro-nanometer scale vibration in imaging of metrological scanning electron microscope

2019 ◽  
Vol 27 (4) ◽  
pp. 860-867
Author(s):  
杜晨辉 DU Chen-hui ◽  
龚 亮 GONG Liang ◽  
蔡小勇 CAI Xiao-yong ◽  
殷伯华 YIN Bo-hua ◽  
江 潮 JIANG Chao ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Nanometer Scale ◽  
Scanning Electron

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.

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 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.

High-Density Ceramic Materials on the Basis of Silicon Carbide

2013 ◽  
Vol 592-593 ◽  
pp. 397-400
Author(s):  
Dinara Sultanovna Dallaeva ◽  
Gulnara Darvinovna Kardashova ◽  
Gadjimet Kerimovich Safaraliev ◽  
Pavel Tománek
Keyword(s):  
Solid Solution ◽  
Silicon Carbide ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Aluminum Nitride ◽  
Hot Pressing ◽  
Manufacturing Process ◽  
Ceramic Materials ◽  
High Density ◽  
Scanning Electron

This study describes the principles of synthesis and technological features of composition ceramics formation on the basis of silicon carbide and aluminum nitride by hot-pressing. The structural properties and composition of the ceramics were investigated by scanning electron microscope and the formation of the solid solution is confirmed. The elements distribution on the surface of failure pattern is shown. The results of the study are useful for optimization of manufacturing process of structural and functional high-density ceramics.

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