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Full-Text Articles in Engineering

Evaluating Effects Of Molecular Heterogeneity On The Non-Linear Mechanical Behavior Of Epoxy Networks, Zhan Hang Yang Nov 2014

Evaluating Effects Of Molecular Heterogeneity On The Non-Linear Mechanical Behavior Of Epoxy Networks, Zhan Hang Yang

Doctoral Dissertations

This thesis describes synthetic and processing strategies to formulate epoxies resins with molecular heterogeneity to achieve enhanced engineering properties. The network heterogeneities include chemical differences in stiffness and crosslink density, as well as mechanical difference in baseline energy state. The focus is to understand the fundamental structure-process-property relationships in these unusual network polymers, especially the post-yield responses and fracture toughness. The main characterization techniques to probe the complex network architectures are dynamic mechanical spectroscopy and compression tests. Ductility and governing parameters are also proposed to describe the relationships between molecular structures and physical properties. Three different staged fabrication strategies are …


Mechanical Behavior Of Compression Molded Polyethylene Terephthalate, Daniel Cole Greinke, Paul Jackson Mcewan, Dan Tran Jun 2014

Mechanical Behavior Of Compression Molded Polyethylene Terephthalate, Daniel Cole Greinke, Paul Jackson Mcewan, Dan Tran

Materials Engineering

The purpose of this project was to investigate the effects of time, temperature, and pressure on the tensile strength and elastic modulus of recycled PET. Compression molding trials were performed on shredded PET bottles to produce tensile test specimens conforming to ASTM D638-03. Aluminum molds containing the PET were mechanically fastened together at the desired pressure and heated in an electric oven. The resulting specimens were subjected to tensile testing for analysis. This screening experiment failed to generate any statistically significant data concerning the factors of interest. These preliminary results may be used to design a more systematic follow-up study.


Optimizing Lempel-Ziv Factorization For The Gpu Architecture, Bryan Ching Jun 2014

Optimizing Lempel-Ziv Factorization For The Gpu Architecture, Bryan Ching

Master's Theses

Lossless data compression is used to reduce storage requirements, allowing for the relief of I/O channels and better utilization of bandwidth. The Lempel-Ziv lossless compression algorithms form the basis for many of the most commonly used compression schemes. General purpose computing on graphic processing units (GPGPUs) allows us to take advantage of the massively parallel nature of GPUs for computations other that their original purpose of rendering graphics. Our work targets the use of GPUs for general lossless data compression. Specifically, we developed and ported an algorithm that constructs the Lempel-Ziv factorization directly on the GPU. Our implementation bypasses the …


Optimal Basis For Ultrasound Rf Apertures: Applications To Real-Time Compression And Beamforming, Sharmin Kibria Jan 2014

Optimal Basis For Ultrasound Rf Apertures: Applications To Real-Time Compression And Beamforming, Sharmin Kibria

Masters Theses 1911 - February 2014

Modern medical ultrasound machines produce enormous amounts of data, as much as several gigabytes/sec in some systems. The challenges of generating, storing, processing and reproducing such voluminous data has motivated researchers to search for a feasible compression scheme for the received ultrasound radio frequency (RF) signals. Most of this work has concentrated on the digitized data available after sampling and A/D conversion. We are interested in the possibility of compression implemented directly on the received analog RF signals; hence, we focus on compression of the set of signals in a single receive aperture. We first investigate the model-free approaches to …


Behaviour Of Gfrp Tube Reinforced Concrete Columns Under Axial Compression, Weiqiang Wang, M Neaz Sheikh, Muhammad N. S Hadi, Blake Lyons Jan 2014

Behaviour Of Gfrp Tube Reinforced Concrete Columns Under Axial Compression, Weiqiang Wang, M Neaz Sheikh, Muhammad N. S Hadi, Blake Lyons

Faculty of Engineering and Information Sciences - Papers: Part A

This paper reports the result of an experimental investigation on the behaviour of Glass Fibre Reinforced Polymer (GFRP) tube reinforced concrete columns under axial compression. The GFRP tube was placed into the concrete to provide reinforcement both in the longitudinal and transverse directions. In this study, a total of 8 columns with 150 mm diameter and 300 mm height were cast and tested under axial compression. The columns were divided into four groups and each group contains two identical columns. The first group had two columns of plain concrete, and the remaining three groups were reinforced with solid, axially perforated …


Effects Of Temperature And Strain Rate On Microstructure And Mechanical Properties Of High Chromium Cast Iron/Low Carbon Steel Bimetal Prepared By Hot Diffusion-Compression Bonding, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Dengfu Chen, Jianzhong Xu, Xiaoming Zhang, Dianyao Gong Jan 2014

Effects Of Temperature And Strain Rate On Microstructure And Mechanical Properties Of High Chromium Cast Iron/Low Carbon Steel Bimetal Prepared By Hot Diffusion-Compression Bonding, Xingjian Gao, Zhengyi Jiang, Dongbin Wei, Sihai Jiao, Dengfu Chen, Jianzhong Xu, Xiaoming Zhang, Dianyao Gong

Faculty of Engineering and Information Sciences - Papers: Part A

The objective of this study is to develop a hot diffusion-compression bonding process for cladding low carbon steel (LCS) to high chromium cast iron (HCCI) in solid-state. The influence of temperature (950-1150 degrees C) and strain rate (0.001-1 s (1)) on microstructure, hardness and bond strength of the HCCI/LCS bimetal were investigated. The interface microstructure reveals that the unbonded region can only be found for 950 degrees C due to lack of diffusion, while the intergrowth between the constituent metals occurred at and above 1100 degrees C. When bonding temperature increases to 1150 degrees C, a carbide-free zone was observed …