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Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov Nov 2011

Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov

Alex Remennikov

Recent findings indicate one of major causes of damages, which is attributed to the resonant behaviours, in a railway track and its components. Basically, when a railway track is excited to generalised dynamic loading, the railway track deforms and then vibrates for certain duration. Dynamic responses of the railway track and its components are the key to evaluate the structural capacity of railway track and its components. If a dynamic loading resonates the railway track’s dynamic responses, its components tend to have the significant damage from excessive dynamic stresses. For example, a rail vibration could lead to defects in rails …


A Large Deformation, Rotation-Free, Isogeometric Shell, D. J. Benson, Y. Bazilevs, Ming-Chen Hsu, T. J. R. Hughes Mar 2011

A Large Deformation, Rotation-Free, Isogeometric Shell, D. J. Benson, Y. Bazilevs, Ming-Chen Hsu, T. J. R. Hughes

Ming-Chen Hsu

Conventional finite shell element formulations use rotational degrees of freedom to describe the motion of the fiber in the Reissner–Mindlin shear deformable shell theory, resulting in an element with five or six degrees of freedom per node. These additional degrees of freedom are frequently the source of convergence difficulties in implicit structural analyses, and, unless the rotational inertias are scaled, control the time step size in explicit analyses. Structural formulations that are based on only the translational degrees of freedom are therefore attractive. Although rotation-free formulations using C0 basis functions are possible, they are complicated in comparison to their C1 …


Porosity Reduction Model In Titanium– Hydroxyapatite Fgm Composites Using Shrinkage Measurement, Ahmed A. Madfa Jan 2011

Porosity Reduction Model In Titanium– Hydroxyapatite Fgm Composites Using Shrinkage Measurement, Ahmed A. Madfa

Ahmed A. Madfa

A multilayered titanium (Ti)–hydroxyapatite (HA) functionally graded material was produced via pressureless sintering at 1100uC. The initial and final porosities were determined via shrinkage measurements. The final porosity verification was carried out by the Archimedes method. The experimental porosity measurements were compared with two proposed models. The macroscopic and microstructure features and the measured porosities confirmed that the volume fraction porosity was associated with both matrix and reinforcing particles in all cases. The percolation threshold was observed at x50?75 in the xTiz(12x)HA mixture.


Fabrication And Characterization Of Graphene Hydrogel Via Hydrothermal Approach As A Scaffold For Preliminary Study Of Cell Growth, Huang Nay Ming Jan 2011

Fabrication And Characterization Of Graphene Hydrogel Via Hydrothermal Approach As A Scaffold For Preliminary Study Of Cell Growth, Huang Nay Ming

Huang Nay Ming

Three-dimensional assembly of graphene hydrogel is rapidly attracting the interest of researchers because of its wide range of applications in energy storage, electronics, electrochemistry, and waste water treatment. Information on the use of graphene hydrogel for biological purposes is lacking, so we conducted a preliminary study to determine the suitability of graphene hydrogel as a substrate for cell growth, which could potentially be used as building blocks for biomolecules and tissue engineering applications. A three-dimensional structure of graphene hydrogel was prepared via a simple hydrothermal method using two-dimensional large-area graphene oxide nanosheets as a precursor. The concentration and lateral size …


Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr. Jan 2011

Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr.

Eng-Poh Ng

Lubricants play a significant part in current environmental considerations since they are an integral and indispensable component of modern technology. The production, application and disposal of the lubricants have to follow increasingly strict requirements for protecting the environment and living organisms. In this respect, molecular sieve (LTL type zeolite) is investigated as a potential environmentally friendly alternative to traditional antioxidant additives for lubricant oils. Accelerated oxidation experiments using pure base oil and additivated base oil in the presence of the LTL molecular sieve are carried out in parallel, and the oxidation processes are monitored by FT-IR spectroscopy, spectrophotometry, chromatography, total …