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Online since: February 2021
Authors: Shahid Akhtar, Sten Yngve Larsen
The effect of different processing parameters including dispersant type and amount, mixer type and mixing time, and different binder levels is investigated with respect to physical and mechanical properties.
All those interfacial properties affect macro-level material behaviour.
Retaining a high aspect ratio of the nanofibers, enabling the efficient transfer of the load to the nanofiber, is very critical toward an improvement of the mechanical properties of nano composites [28].
Endo, Mechanical and thermal properties of vapour-grown carbon nanofiber and polycarbonate sheet, Mat.Lett. 59 20053514-3520
Schulte, Influence of different carbon nanotubes on the mechanical properties of epoxy matrix composites- A comparative study, Comp.
All those interfacial properties affect macro-level material behaviour.
Retaining a high aspect ratio of the nanofibers, enabling the efficient transfer of the load to the nanofiber, is very critical toward an improvement of the mechanical properties of nano composites [28].
Endo, Mechanical and thermal properties of vapour-grown carbon nanofiber and polycarbonate sheet, Mat.Lett. 59 20053514-3520
Schulte, Influence of different carbon nanotubes on the mechanical properties of epoxy matrix composites- A comparative study, Comp.
Online since: October 2015
Authors: Irina Kurzina, Konstantin V. Rubtsov, Aleksandr V. Medovnik, Andrei V. Kazakov, Irina Puhova
Electron beam processing is one of the effective methods for modification of surface material properties.
The comparison of hydroxyl group (υ (-О-Н)) and carbonyl group (υ (-С=О)) transmission band intensity factors reveals that the sample PVA-4 treated by electron beam for 300 μs has the highest hydroxyl group absorption capacity.
These processes of restructuring led to the increase of mechanical properties and crystallinity of the material.
Chemical reaction and improvement of physicochemical properties have been established, that can significantly affect the physicochemical and mechanical properties of the materials.
Lau Effects of electron beam irradiation on mechanical properties and nanostructural–morphology of montmorillonite added polyvinyl alcohol composite, Composites: Part B 63 (2014) 141-153
The comparison of hydroxyl group (υ (-О-Н)) and carbonyl group (υ (-С=О)) transmission band intensity factors reveals that the sample PVA-4 treated by electron beam for 300 μs has the highest hydroxyl group absorption capacity.
These processes of restructuring led to the increase of mechanical properties and crystallinity of the material.
Chemical reaction and improvement of physicochemical properties have been established, that can significantly affect the physicochemical and mechanical properties of the materials.
Lau Effects of electron beam irradiation on mechanical properties and nanostructural–morphology of montmorillonite added polyvinyl alcohol composite, Composites: Part B 63 (2014) 141-153
Online since: June 2015
Authors: Mohamad Rusop, A.S. Ismail, M.H. Mamat
They have a good adsorbing and desorbing properties.
There are still a few reports on the effect of optical properties on the humidity detection especially the type of metal oxide that has good electrical properties such as ZnO and TiO2 [6].
They found that the electrical properties of Sn doped is higher compare to the undoped due to the increasing of free electron but through the characterization of humidity sensing properties, the found that by the addition of Sn, the surface structure has become bigger and less in porosity and that also contribute to the low surface volume.
The type of structures depend on different kind of factors such as fabrication methods, types of dopants, types of precursors, types of stabilizers and also other parameters such as temperature and environment.
They found that the sensor has good sensing properties due to the high porosity of the surface which increase the adsorption process.
There are still a few reports on the effect of optical properties on the humidity detection especially the type of metal oxide that has good electrical properties such as ZnO and TiO2 [6].
They found that the electrical properties of Sn doped is higher compare to the undoped due to the increasing of free electron but through the characterization of humidity sensing properties, the found that by the addition of Sn, the surface structure has become bigger and less in porosity and that also contribute to the low surface volume.
The type of structures depend on different kind of factors such as fabrication methods, types of dopants, types of precursors, types of stabilizers and also other parameters such as temperature and environment.
They found that the sensor has good sensing properties due to the high porosity of the surface which increase the adsorption process.
Online since: September 2011
Authors: J. Froitzheim, J.E. Svensson
Nanocoatings for SOFC Interconnects - Mitigating Chromium Volatilization and Improving Corrosion Properties
J.
Secondly is the ability of the metallic interconnect to form a thin protective oxide one of the most important lifetime limiting factors for SOFC.
Ferritic steels have a number of advantages, e.g. low surface scale resistance, ease of fabrication, good mechanical properties and excellent thermal matching to the other SOFC components.
The problem of cathode poisoning due to volatile Cr species is well- known and there are numerous publications discussing the mechanism by which Cr affects SOFC performance [1, 2].
Secondly is the ability of the metallic interconnect to form a thin protective oxide one of the most important lifetime limiting factors for SOFC.
Ferritic steels have a number of advantages, e.g. low surface scale resistance, ease of fabrication, good mechanical properties and excellent thermal matching to the other SOFC components.
The problem of cathode poisoning due to volatile Cr species is well- known and there are numerous publications discussing the mechanism by which Cr affects SOFC performance [1, 2].
Online since: February 2012
Authors: Si Jie Chen, Heng Juan Tang
Thermal stress is often an important factor in welding crack formation, and it is caused by strain aging embrittlement of the heat source.
Heat transfer is brought about by welding, metallurgy, and the mechanical complexity of the process.
The simulated parameters of the materials’ physical properties are listed in Table 1.
Thus, the performance of these joints is substantially affected.
The results from the joint analysis of tensile mechanical properties and those from numerical simulation showed a combination of solid joint conditions, which are usually in the vicinity of the weld fracture specimen as shown in Fig. 7.
Heat transfer is brought about by welding, metallurgy, and the mechanical complexity of the process.
The simulated parameters of the materials’ physical properties are listed in Table 1.
Thus, the performance of these joints is substantially affected.
The results from the joint analysis of tensile mechanical properties and those from numerical simulation showed a combination of solid joint conditions, which are usually in the vicinity of the weld fracture specimen as shown in Fig. 7.
Online since: December 2012
Authors: Hou Jun Lu, Xi Liu, Dao Fang Chang
From the definition and research content, the influencing factors are multi-level and multi-faceted, which leads to use AHP to ensure the set of influencing factors.
Transparency, degree of mixing and mapping way are the indicator to judge the mapping distortion of the picture and polygonal model; (3) Material includes three factors: material’s color of tree-dimensional model, light color of tree-dimensional model and reflective property of tree-dimensional model.
(1) Define the objectives and evaluation factors: assumed there are n indicators,
Experts from different fields affect the degree is not the same evaluation results, so we should consider expert judgment impact factor.
The working conditions for front area in terminals are complex with the addition of the natural factors.
Transparency, degree of mixing and mapping way are the indicator to judge the mapping distortion of the picture and polygonal model; (3) Material includes three factors: material’s color of tree-dimensional model, light color of tree-dimensional model and reflective property of tree-dimensional model.
(1) Define the objectives and evaluation factors: assumed there are n indicators,
Experts from different fields affect the degree is not the same evaluation results, so we should consider expert judgment impact factor.
The working conditions for front area in terminals are complex with the addition of the natural factors.
Online since: February 2008
Authors: Sam Kharchenko, Jack Huang
Physical Phenomena of Thermoplastic Articles in the Vicinity of Their
Glass Transition Temperatures
Sam Kharchenko and Jack Huang
Masco Corporation OTS-R&D, 7500 Holland Road, Taylor, Michigan 48180, USA
skharchenko@masco-rd.com, jhuang@masco-rd.com
Keywords: Environmental Factor, Thermoplastic, Glass Transition Temperature, Heat History,
Thermal Cycle, Dimensional Stability, Residual Stress, Coefficient of Thermal Expansion,
Deformation.
Introduction When choosing thermoplastic material for an application, often the focus is on mechanical properties, processing conditions, and costs.
While analytical models for the prediction of the bowing and the warping due to temperature gradients have already been developed [1, 2] and many studies have tackled these physical phenomena in great detail [3-5], we seek to understand how periodic temperature gradients affect the dimensional stability of thermoplastic articles, especially when temperature reaches the vicinity of their glass transitions.
To understand & separate the effects on dimensional changes from various factors, we first evaluated the extent of process-induced stresses by measuring a sample's shrinkage in the longitudinal direction when the sample was subjected to periodic uniform heating in the oven (Fig. 2).
Introduction When choosing thermoplastic material for an application, often the focus is on mechanical properties, processing conditions, and costs.
While analytical models for the prediction of the bowing and the warping due to temperature gradients have already been developed [1, 2] and many studies have tackled these physical phenomena in great detail [3-5], we seek to understand how periodic temperature gradients affect the dimensional stability of thermoplastic articles, especially when temperature reaches the vicinity of their glass transitions.
To understand & separate the effects on dimensional changes from various factors, we first evaluated the extent of process-induced stresses by measuring a sample's shrinkage in the longitudinal direction when the sample was subjected to periodic uniform heating in the oven (Fig. 2).
Online since: September 2016
Authors: Tian Yuan Fan, Zongjin Li
When designing high-rise structures, the deformation under service condition is the dominant control criteria so that among various mechanical properties of concrete, not only compressive strength but modulus of elasticity is also critical.
It was found that water/binder ratio and properties of aggregate are two main factors determining the elastic modulus of concrete [4].
Then, the properties of the high modulus concrete developed are characterized.
Effect of aggregate properties on the strength and stiffness of lightweight concrete [J].
The effect of silica fume and high-volume Class C fly ash on mechanical properties, chloride penetration and freeze–thaw resistance of self-compacting concrete [J].
It was found that water/binder ratio and properties of aggregate are two main factors determining the elastic modulus of concrete [4].
Then, the properties of the high modulus concrete developed are characterized.
Effect of aggregate properties on the strength and stiffness of lightweight concrete [J].
The effect of silica fume and high-volume Class C fly ash on mechanical properties, chloride penetration and freeze–thaw resistance of self-compacting concrete [J].
Online since: January 2013
Authors: Xian Xiao Peng, Gu Hua Li, Wu Huang, Fu Hai Li, Xiao Chun He
However, due to the slow speed of the alkali-aggregate reaction, destructive effects of expansion appear after 8 years, or even 20 years generally, and there are many factors affect expansion, so controversy still exists on some issues.
Mechanical properties of slate meet the requirements of aggregate, but it has high alkali activity [5, 6, 7].
And k represents the scale factor.
[12] M.Moisson, M.Cyr*, E.Ringot and A.Carles-Gibergues: Efficiency of Reactive Aggregate Power in controlling the Expansion of Concrete Affected by Alkali-silica Reaction(ASR), In: Proc. of 12th International Conference on AAR in Concrete, Page: 617-624 [13] Mingshu Tang, Wanrong Xue: Several issues on the alkali-aggregate reaction, In: Journal of the Chinese Ceramic Society, Page: 110-116 (1963) In Chinese
[14] Stéphane Multon, Alain Sellier and Martin Cyr: Chemo–mechanical modeling for prediction of alkali silica reaction (ASR) expansion, In: Cement and Concrete Research No. 39 Page: 490-500 (2009)
Mechanical properties of slate meet the requirements of aggregate, but it has high alkali activity [5, 6, 7].
And k represents the scale factor.
[12] M.Moisson, M.Cyr*, E.Ringot and A.Carles-Gibergues: Efficiency of Reactive Aggregate Power in controlling the Expansion of Concrete Affected by Alkali-silica Reaction(ASR), In: Proc. of 12th International Conference on AAR in Concrete, Page: 617-624 [13] Mingshu Tang, Wanrong Xue: Several issues on the alkali-aggregate reaction, In: Journal of the Chinese Ceramic Society, Page: 110-116 (1963) In Chinese
[14] Stéphane Multon, Alain Sellier and Martin Cyr: Chemo–mechanical modeling for prediction of alkali silica reaction (ASR) expansion, In: Cement and Concrete Research No. 39 Page: 490-500 (2009)
Online since: March 2008
Authors: Jian Feng Li, Yi Ming Rong, Dong Lu, Jie Sun, Zhong Qiu Wang, Jun Zhou
A Study of Exit-Burr Formation Mechanism Using the Finite Element
Method in Micro-Cutting of Aluminum Alloy
Dong Lu1,a, Jianfeng Li1,b, Yiming Rong2,c
, Jie Sun
1,d, Jun Zhou
1,e
and Zhongqiu Wang1,f
1
School of Mechanical Engineering, Shandong University, Jinan, China, 250061
2
Worcester Polytechnic Institute, Worcester, MA, USA, 01609
a
ludong80@gmail.com; bljf@sdu.edu.cn; crong@wpi.com; dsunjie@sdu.edu.cn;
e
zhenzhang@mail.sdu.edu.cn; fzhongqiu.wang@gmail.com
Keywords: Micro-cutting, Exit-burr, Formation Mechanism, Finite Element Method
Abstract.
Mechanical micro-cutting is capable of fabricating high profile accuracy, surface finish quality at reasonably low cost.
φ φ φ mµ mµ Fig.3 Burr formation stages Simulation Results and Analysis There are some factors affecting burr formation, such as cutting speed, uncut chip thickness, tool edge radius, and workpiece material properties.
The Formation and Properties of Machining Burrs (Logan, Utah State University, 1973).
Mechanical micro-cutting is capable of fabricating high profile accuracy, surface finish quality at reasonably low cost.
φ φ φ mµ mµ Fig.3 Burr formation stages Simulation Results and Analysis There are some factors affecting burr formation, such as cutting speed, uncut chip thickness, tool edge radius, and workpiece material properties.
The Formation and Properties of Machining Burrs (Logan, Utah State University, 1973).