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Full-Text Articles in Mechanical Engineering

Study Of Take-Up Velocity In Enhancing Tensile Properties Of Aligned Electrospun Nylon 6 Fibers, Johnny F. Najem Dec 2009

Study Of Take-Up Velocity In Enhancing Tensile Properties Of Aligned Electrospun Nylon 6 Fibers, Johnny F. Najem

Mechanical Engineering Faculty Research

The variation of both the tensile properties and thermal properties of aligned electrospun fibers with the take-up velocity (TUV) of disc collector has not been widely investigated due to the difficulty of handling aligned nanofibers and measuring low loads. In this thesis, 25% of nylon 6 was dissolved in formic acid and then electrospun into fibers and the fibers were aligned using a rotating disc collector. We evaluated the tensile and thermal properties, average fiber diameter, crystallinity, crystalline morphology, molecular and crystalline orientation of aligned electrospun nylon 6 nanofibers as a function of TUV based on a disc collector. It …


Static And Dynamic Responsive Behavior Of Polyelectrolyte Brushes Under External Electrical Field, Hui Ouyang, Zhenhai Xia, Jiang Zhe Apr 2009

Static And Dynamic Responsive Behavior Of Polyelectrolyte Brushes Under External Electrical Field, Hui Ouyang, Zhenhai Xia, Jiang Zhe

Mechanical Engineering Faculty Research

The static and dynamic behaviors of partially charged and end-grafted polyelectrolyte brushes in response to electric fields were investigated by means of molecular dynamics simulation. The results show that the polymer brushes can be partially or fully stretched by applying an external electric field. Moreover, the brushes can switch reversibly from collapsed to stretched states, fully responding to the AC electric stimuli, and the gating response frequency can reach a few hundred MHz. The effects of the grafting density, the charge fraction of the brushes and the strength of the electric field on the average height of the polymer brushes …


Particle Swarm Optimization Approach For Maximizing The Yield Of A Coal Preparation Plant, Vishal Gupta, Hussain Unjawala, Ajay Mohan Mahajan, Manoj Mohanty Jan 2009

Particle Swarm Optimization Approach For Maximizing The Yield Of A Coal Preparation Plant, Vishal Gupta, Hussain Unjawala, Ajay Mohan Mahajan, Manoj Mohanty

Mechanical Engineering Faculty Research

This paper presents the use of particle swarm optimization to maximize the clean coal yield of a coal preparation plant that typically has multiple cleaning circuits that produce the same product quality so that the blend of clean coal meets the targeted product quality contraints. Particle swarm is used for the yield optimization while satisfying multiple product quality restraints. The results show a 2.73% increase in the yield can be achieved leading to additional revenue of $5,460,000 per annum for a plant producing 10 million tons of clean coal per year without significantly adding to the implementation/operation cost.


Material Selection Of Z-Fibre In Stitched Composites - Experimental And Analytical Comparison Approach, Kwek Tze Tan, N. Watanabe, M. Sano, M. Takase, Y. Iwahori, H. Hoshi Jan 2009

Material Selection Of Z-Fibre In Stitched Composites - Experimental And Analytical Comparison Approach, Kwek Tze Tan, N. Watanabe, M. Sano, M. Takase, Y. Iwahori, H. Hoshi

Mechanical Engineering Faculty Research

Strain energy release rates are measured and compared for laminated composites stitched with different fibre materials – Carbon, Kevlar and Vectran. DCB test and FE simulation are performed to evaluate the interlaminar toughness. It is proven that Vectran provides the toughest interlaminar reinforcement and is most suitable for Zfibre application.


Numerical Modeling Of The Constraint Effects On Cleavage Fracture Toughness, Sunil Prakash, Xiaosheng Gao, T. S. Srivatsan Jan 2009

Numerical Modeling Of The Constraint Effects On Cleavage Fracture Toughness, Sunil Prakash, Xiaosheng Gao, T. S. Srivatsan

Mechanical Engineering Faculty Research

Cleavage fracture has been an important subject for engineers primarily because of its catastrophic nature and consequences. Experimental studies of cleavage fracture did reveal a considerable amount of scatter and provided evidence of noticeable constraint effects. This did provide the motivation for the development of statistical-based and micromechanics-based methods in order to both study and analyze the problem. The Weibull stress model, which is based on the weakest link statistics, uses two parameters (m and σ u) to effectively describe the inherent distribution of the micro-scale cracks once plastic deformation has occurred and to concurrently define the relationship between the …