Atomic‐Level Insight into the Formation of Subsurface Dislocation Layer and Its Effect on Mechanical Properties During Ultrafast Laser Micro/Nano Fabrication

2021 ◽  
pp. 2108802
Author(s):  
Jiawang Xie ◽  
Jianfeng Yan ◽  
Dezhi Zhu ◽  
Guangzhi He
Author(s):  
Lulu An ◽  
Xu Zhao ◽  
Tonghui Zhao ◽  
Deli Wang

Anion exchange membrane fuel cell (AEMFC) is becoming highly attractive for hydrogen utilization owing to the advantages of employing economic catalysts in alkaline electrolytes. Nevertheless, the kinetics of anodic hydrogen...


2021 ◽  
Vol 120 (3) ◽  
pp. 224a-225a
Author(s):  
Milka Doktorova ◽  
George Khelashvili ◽  
Trivikram R. Molugu ◽  
Rana Ashkar ◽  
Michael F. Brown

Author(s):  
Fathima Banu Raza ◽  
Anand Kumar

The o-rings in ball retained overdentures deteriorate with time and need replacement to restore the retentive quality. We evaluated retrospectively the mechanical properties of o-rings after 3 years in function in one and two-piece implant-supported overdentures. The o-rings were retrieved from one-piece (Myriad snap, Equinox-Straumann, 3.3 x 13mm) and two-piece (Neo Biotech, 3.3 x 13mm) implant-supported overdenture patients. A total of 16 pairs of matrices were tested for wear, type of damage and elasticity using Pin on Disc method, USB Digital Camera in 30x zoom and Universal Tensile Machine respectively. The statistical analysis for independent groups were done with the Mann-Whitney U test. Assessment of used O-rings showed 84% more wear in the two-piece system with an abrasive type of damage while 46% wear in the one-piece system with a compressive type of damage. The o-rings in one-piece system showed increase in elongation and maximum displacement to 2% and 7% respectively, while two-piece system showed decrease in elongation and maximum displacement by 13% and 6% respectively. In one-piece system, the loss of retention was more with slow wear rate and in two-piece system, the wear resistance of O-rings decreased due to increased stiffness. Further studies to evaluate the changes in O-ring with increased sample size and at interval 1 year will pave way for insight into the progressive changes in the mechanical properties of an O-ring.


2017 ◽  
Vol 19 (5) ◽  
pp. 3498-3505 ◽  
Author(s):  
Kenichi Koizumi ◽  
Katsuyuki Nobusada ◽  
Mauro Boero

Reaction mechanism of CO molecules onto a Cu/CeO2 surface and morphological changes.


2017 ◽  
Vol 56 (40) ◽  
pp. 12191-12196 ◽  
Author(s):  
Yuanjie Cao ◽  
Si Chen ◽  
Qiquan Luo ◽  
Huan Yan ◽  
Yue Lin ◽  
...  

1995 ◽  
Vol 400 ◽  
Author(s):  
G. D’Agostino ◽  
H. Van Swygenhoven

AbstractThe present paper is aimed at studying the physics of a nickel nanophase at the atomic level. A dense polycrystal has been designed by ideally growing many nano-crystals from randomly distributed seeds and truncating them through a Voronoi construction. The sample has been brought to thermodynamic equilibrium and quenched to its local minimum energy thus leading to a mechanically stable system. The dynamic evolution has been simulated by means of classical molecular dynamics employing a Finnis-Sinclair interactive potential. Owing to the large number of atoms required, a parallel code has been developed. Elastic and plastic behaviour of the simulated sample has been compared with that of a perfect crystal. Evidence of an enhanced plastic behaviour has been observed when severe tensile stresses are applied.


Materials ◽  
2018 ◽  
Vol 11 (2) ◽  
pp. 312 ◽  
Author(s):  
Saverio Maietta ◽  
Teresa Russo ◽  
Roberto De Santis ◽  
Dante Ronca ◽  
Filomena Riccardi ◽  
...  

2019 ◽  
Author(s):  
Kathryn P. Wall ◽  
Harold Hart ◽  
Thomas Lee ◽  
Cynthia Page ◽  
Taviare L. Hawkins ◽  
...  

ABSTRACTMicrotubules are biopolymers that perform diverse cellular functions. The regulation of microtubule behavior occurs in part through post-translational modification of both the α- and β- subunits of tubulin. One class of modifications is the heterogeneous addition of glycine and glutamate residues to the disordered C-terminal tails of tubulin. Due to their prevalence in stable, high stress cellular structures such as cilia, we sought to determine if these modifications alter the intrinsic stiffness of microtubules. Here we describe the purification and characterization of differentially-modified pools of tubulin from Tetrahymena thermophila. We found that glycylation on the α-C-terminal tail is a key determinant of microtubule stiffness, but does not affect the number of protofilaments incorporated into microtubules. We measured the dynamics of the tail peptide backbone using nuclear magnetic resonance spectroscopy. We found that the spin-spin relaxation rate (R2) showed a pronounced decreased as a function of distance from the tubulin surface for the α-tubulin tail, indicating that the α-tubulin tail interacts with the dimer surface. This suggests that the interactions of the α-C-terminal tail with the tubulin body contributes to the stiffness of the assembled microtubule, providing insight into the mechanism by which glycylation and glutamylation can alter microtubule mechanical properties.SIGNIFICANCEMicrotubules are regulated in part by post-translational modifications including the heterogeneous addition of glycine and glutamate residues to the C-terminal tails. By producing and characterizing differentially-modified tubulin, this work provides insight into the molecular mechanisms of how these modifications alter intrinsic microtubule properties such as flexibility. These results have broader implications for mechanisms of how ciliary structures are able to function under high stress.


2021 ◽  
Author(s):  
Meng Li ◽  
Zuzhi Bai ◽  
Xiao Chen ◽  
Cong-Cong Liu ◽  
Jing-Kun Xu ◽  
...  

Abstract Poly(3,4-ethylenedioxythiophene) (PEDOT) has proved its quite competitive thermoelectric properties in flexible electronics with its excellent electrical and mechanical properties. Since the early discovery of PEDOT, considerable experimental progress has been achieved in optimizing and improving thermoelectric properties as a promising organic thermoelectric material (OTE). Among them, theoretical research has made significant contributions to its development. Here the basic physics of conductive PEDOT are reviewed based on the combination of theory and experiment. Its purpose is to provide a new insight into the development of PEDOT, so as to effectively design and preparation of advanced thermoelectric PEDOT material in the future.


Sign in / Sign up

Export Citation Format

Share Document