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Online since: October 2015
Authors: Leila Ebrahimi, Masoud Zare-Shehneh, Hadi Zare-Zardini, Farzad Ferdowsian, Adel Ghorani Azam, Safoura Soleymani, Mahtab Mofidi, Roya Rafati, Hossein Soltaninejad
Nanotechnology is a science to understand and employ the new properties of materials and systems at the nano-scale which shows effects of modern physics - mainly influenced by properties of quantum physics.
Biological properties of these materials were investigated by various research groups.
Different factors influence the antimicrobial activities of CNTs.
Meeks, Ectopic pregnancy: History, incidence, epidemiology, and risk factors.
Industrial Property General Office-state organization for registration of deeds and properties, 2012. 74061(390040571)
Biological properties of these materials were investigated by various research groups.
Different factors influence the antimicrobial activities of CNTs.
Meeks, Ectopic pregnancy: History, incidence, epidemiology, and risk factors.
Industrial Property General Office-state organization for registration of deeds and properties, 2012. 74061(390040571)
Online since: July 2013
Authors: John S. Owen, Mohammed F.M. Hussein, Amged O. Abdelatif
The experimental validation of the model in [2] across different factors involved in the re-anchorage phenomenon is presented.
This is followed by a description of the experiment, specimen properties, and measuring techniques.
A and B are constants that depend on the material and geometrical properties, they are calculated as shown in [2].
DEMEC strain gauges were used to investigate the effect of grout properties on transmission length on nineteen bonded post-tensioned concrete beams [12].
The material properties, pre-stress, and support conditions for each prism are summarised in appendix A.
This is followed by a description of the experiment, specimen properties, and measuring techniques.
A and B are constants that depend on the material and geometrical properties, they are calculated as shown in [2].
DEMEC strain gauges were used to investigate the effect of grout properties on transmission length on nineteen bonded post-tensioned concrete beams [12].
The material properties, pre-stress, and support conditions for each prism are summarised in appendix A.
Online since: October 2010
Authors: Qiu Sheng Yan, Jia Bin Lu, Wei Qiang Gao, Hong Tian
Introduction
With the rapid advancement of the micro-nano technology, micro electro-mechanical systems
(MEMS) characterized by small size and shape has become an emerging technology, but the
fabrication of micro machining tools for the micro components made of brittle materials is one of the
difficulties restricting the advance of MEMS.
Using this characteristic, called the ER or MR effect, to control the mechanical properties, the clutches, dampers, seals and composite beams have been applied in engineering successfully [1,2].
The removal depth (about 0.48µm) at the diamond size of 125µm reduces by a factor of about 10 than that of 5µm.
The abrasive content dispersed in the EMR fluid determines the concentration of the abrasives in the EMR-effect-based tiny-grinding wheel and affects the chains of the EMR particles, then directly influences the polishing performance of the tiny-grinding wheel.
Therefore, the presence of the diamond abrasive can enhance the removal ability of the tiny-grinding wheel, and an appropriate concentration of the diamond abrasive can affect the structure and the effective machining size of the tiny-grinding wheel, whereas too much diamond abrasives have little effect on the polishing performance of the tiny-grinding wheel.
Using this characteristic, called the ER or MR effect, to control the mechanical properties, the clutches, dampers, seals and composite beams have been applied in engineering successfully [1,2].
The removal depth (about 0.48µm) at the diamond size of 125µm reduces by a factor of about 10 than that of 5µm.
The abrasive content dispersed in the EMR fluid determines the concentration of the abrasives in the EMR-effect-based tiny-grinding wheel and affects the chains of the EMR particles, then directly influences the polishing performance of the tiny-grinding wheel.
Therefore, the presence of the diamond abrasive can enhance the removal ability of the tiny-grinding wheel, and an appropriate concentration of the diamond abrasive can affect the structure and the effective machining size of the tiny-grinding wheel, whereas too much diamond abrasives have little effect on the polishing performance of the tiny-grinding wheel.
Online since: September 2008
Authors: Rahmat A. Shoureshi, Sun W. Lim
Change in structural properties due to
damage subsequently affects the dynamic behavior of structures.
Forisomes exert similar mechanical forces in expansion and contraction with a minimum of 0.10N.
In 1880, Jacques and Pierre Curie discovered an unusual phenomenon in certain crystals that exhibit output voltage when exposed to mechanical tension and compression, and experience mechanical strain if exposed to an electric field.
Given that piezo fibers are now manufactured in flexible shapes, as shown in Fig. 5, then they can be bent, flexed even over 200 million cycles without degradation in their properties.
This network can be used to find out system parameters and unknown factors through the training process, which means it achieves the goal of system identification.
Forisomes exert similar mechanical forces in expansion and contraction with a minimum of 0.10N.
In 1880, Jacques and Pierre Curie discovered an unusual phenomenon in certain crystals that exhibit output voltage when exposed to mechanical tension and compression, and experience mechanical strain if exposed to an electric field.
Given that piezo fibers are now manufactured in flexible shapes, as shown in Fig. 5, then they can be bent, flexed even over 200 million cycles without degradation in their properties.
This network can be used to find out system parameters and unknown factors through the training process, which means it achieves the goal of system identification.
Online since: July 2013
Authors: Francesco Aymerich, Dian Shi Feng
Even though the presence of damage is generally accounted for, at the design stage, by the use of very conservative safety factors [4], more advanced damage tolerance concepts [5] are being gradually incorporated in the design process of critical elements of composite blades, so as to take full advantage of the weight-saving potentiality offered by sandwich materials.
Stress-based failure criteria and a sudden property degradation strategy were adopted in [15] to simulate the damage induced by low-velocity impact on the glass-fibre woven skins of sandwich beams.
The elastic and fracture properties of the composite layers used in the FE model, obtained by a series of experimental tests or provided by the material manufacturers, are listed in Table 1.
Table 1 Material properties used in FE analyses.
Layer properties Interface properties E11=122 [GPa]; E22=E33=6.2 [GPa]; v12=v13=0.35; v23=0.5 Xt=1850 [MPa]; Xc=1470 [MPa]; Yt=29 [MPa]; Yc=140 [MPa] Gft=92 [kJ/m2]; Gfc=80 [kJ/m2]; Gmt=520 [J/m2]; Gmc=1610 [J/m2] kN=120 [GPa/mm]; kS=kT=43 [GPa/mm] N=30 [MPa]; S=T=50 [MPa] GIC=520 [J/m2]; GIIC=GIIIC=920 [J/m2] The accuracy of the FE model was finally assessed through comparison with experimental data from impact tests on sandwich plates with thin composite skins laid up in a cross-ply [0/903/0] sequence.
Stress-based failure criteria and a sudden property degradation strategy were adopted in [15] to simulate the damage induced by low-velocity impact on the glass-fibre woven skins of sandwich beams.
The elastic and fracture properties of the composite layers used in the FE model, obtained by a series of experimental tests or provided by the material manufacturers, are listed in Table 1.
Table 1 Material properties used in FE analyses.
Layer properties Interface properties E11=122 [GPa]; E22=E33=6.2 [GPa]; v12=v13=0.35; v23=0.5 Xt=1850 [MPa]; Xc=1470 [MPa]; Yt=29 [MPa]; Yc=140 [MPa] Gft=92 [kJ/m2]; Gfc=80 [kJ/m2]; Gmt=520 [J/m2]; Gmc=1610 [J/m2] kN=120 [GPa/mm]; kS=kT=43 [GPa/mm] N=30 [MPa]; S=T=50 [MPa] GIC=520 [J/m2]; GIIC=GIIIC=920 [J/m2] The accuracy of the FE model was finally assessed through comparison with experimental data from impact tests on sandwich plates with thin composite skins laid up in a cross-ply [0/903/0] sequence.
Online since: October 2013
Authors: Xiang Gou, Lian Sheng Liu, Zi Fang Wang, Guang Yang, Jin Xiang Wu, En Yu Wang, Wen Yong Liu, Kai Zhang
Boyano et al. [12] prepared the catalysts of V2O5/AC and V2O5/Al2O3 by impregnation method and studied their catalytic and mechanical properties.
Gao et al. [13] studied the catalytic properties of V2O5/AC in the temperature range of 100-300℃, at the GHSV of 24000 h-1.
These good properties make carbon nanotube become a new type of catalyst support, furthermore it has attracted the attention of many scholars in recent years.
For some kinds of the catalyst, however, NO conversion decreases first and then increases with the increase of temperature.Therefore, temperature is the important factor affecting the catalytic activity.
Gao et al. [13] studied the catalytic properties of V2O5/AC in the temperature range of 100-300℃, at the GHSV of 24000 h-1.
These good properties make carbon nanotube become a new type of catalyst support, furthermore it has attracted the attention of many scholars in recent years.
For some kinds of the catalyst, however, NO conversion decreases first and then increases with the increase of temperature.Therefore, temperature is the important factor affecting the catalytic activity.
Online since: April 2011
Authors: Zhi Wei Zhang, Jin Chun Song, Sheng Hao Zhou, Song Li
Performance Analysis of Hydrostatic Slideways Systems with Different Types of Restrictors
Shenghao ZHOU1, a, Jinchun SONG1,b , Zhiwei ZHNANG1 and Song LI1
1School of Mechanical Engineering and Automation, Northeastren University, Shenyang, China
ashhzhou@mail.neu.edu.cn, bjchsong@mail.neu.edu.cn
Keywords: Hydrostatic slideways, closed-type slideways, restrictor, oil film stiffness.
Introduction With such advantageous characteristics as low friction, wide range of speed, good anti-vibration property and long service life, oil lubricated hydrostatic sideways system have become more and more important in precision machine tool technology [1].
According to the mechanical structure hydrostatic slideways has two types of open one and closed one.
One of these is the passive compensation restrictor that adopts flexible or movable element directly affected by the pressure change within the oil-film; the other is the active compensation restrictor that possesses controllable element driven by an auxiliary actuator in accordance with controlling algorithm.
Mechanical Structure Model Hydrostatic slideways support loads by pressuring lubricant oil into a slideways pocket.
Introduction With such advantageous characteristics as low friction, wide range of speed, good anti-vibration property and long service life, oil lubricated hydrostatic sideways system have become more and more important in precision machine tool technology [1].
According to the mechanical structure hydrostatic slideways has two types of open one and closed one.
One of these is the passive compensation restrictor that adopts flexible or movable element directly affected by the pressure change within the oil-film; the other is the active compensation restrictor that possesses controllable element driven by an auxiliary actuator in accordance with controlling algorithm.
Mechanical Structure Model Hydrostatic slideways support loads by pressuring lubricant oil into a slideways pocket.
Online since: February 2020
Authors: Ken Chuan Cheng, Yan Cherng Lin, Kuan Yu Chen, A Cheng Wang
Finishing Performance of the Abrasive Flow Machining
in Complex Holes by Using Helical Cores
A-Cheng Wang1, a*, Ken-Chuan Cheng1, b,
Kuan-Yu Chen2, c and Yan-Cherng Lin3, d
1Department of Mechanical Engineering, Chien Hsin University of Science and Technology,
Taoyuan city, 32097, Taiwan
2Department of Mechanical Engineering, Chung Yuan Christian University,
Taoyuan city, 32023, Taiwan
3Department of Mechanical Engineering, Nan Kai University of Technology,
Nantou County 54243, Taiwan
aacwang@uch.edu.tw, bkccheng20@gmail.com, cgychen@cycu.edu.tw, dycline@nkut.edu.tw
Keywords: Abrasive flow machining, Abrasive gel, Helical cores, Even surface
Abstract.
These silicone gels have lower flow property and do not stick on the workpiece surface after contact, so that they are the good abrasive media in AFM.
However, the gap between the hole surface and helical tip is the main factor, which can control the shear forces of the abrasive gel in polishing process.
Helical turn is an important parameter in the complex hole finishing, since it affects the angle of multi-axial motions of the abrasive gel in AFM.
These silicone gels have lower flow property and do not stick on the workpiece surface after contact, so that they are the good abrasive media in AFM.
However, the gap between the hole surface and helical tip is the main factor, which can control the shear forces of the abrasive gel in polishing process.
Helical turn is an important parameter in the complex hole finishing, since it affects the angle of multi-axial motions of the abrasive gel in AFM.
Online since: July 2006
Authors: Geoff M. Scamans, Andreas Afseth, Martin Strangwood, Yudie Yuan, Brian J. Connolly, Rajan Ambat, Alison J. Davenport
However, higher angle boundaries show highly
variable precipitation and corrosion susceptibility: critical factors are the grain boundary plane and
precipitate/matrix crystallographic relationship.
Automotive manufacturers favour the use of AA5182, which contains 4.5 wt% Mg, because of its good mechanical properties.
The rate of SCC propagation will therefore be affected by the crystallographic texture of the material.
Automotive manufacturers favour the use of AA5182, which contains 4.5 wt% Mg, because of its good mechanical properties.
The rate of SCC propagation will therefore be affected by the crystallographic texture of the material.
Online since: April 2018
Authors: Volker Schulze, Eric Segebade, Johannes Schneider
These coatings naturally exhibit different interface properties such as friction and heat partition coefficients depending on the workpiece material.
Still, they are not suited to provide in-depth analyses of surface layer states being induced by cutting operations on account of the disregard of influencing factors such as relative speed.
Up to a point, dependencies on these factors can be added to common models by introducing state-dependent friction coefficients.
Work in this field continues due to the interest in mechanical properties of nanocrystalline materials.
Zalisz, Characterization of the friction properties of various coatings at the tool—chip—workpiece interfaces in dry machining of AISI 4140 steel, Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 222 (4) (2008) 617-627
Still, they are not suited to provide in-depth analyses of surface layer states being induced by cutting operations on account of the disregard of influencing factors such as relative speed.
Up to a point, dependencies on these factors can be added to common models by introducing state-dependent friction coefficients.
Work in this field continues due to the interest in mechanical properties of nanocrystalline materials.
Zalisz, Characterization of the friction properties of various coatings at the tool—chip—workpiece interfaces in dry machining of AISI 4140 steel, Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology 222 (4) (2008) 617-627