Engineering Commons^™

Synthesis And Characterization Of Diamond-Like Carbon Thin Films For Biomedical Applications, Russell Lee Leonard

Masters Theses

Diamond-like carbon (DLC) thin films were produced by pulsed laser deposition (PLD) on silicon, fused silica, and silicon nitride substrates. The films produced were either undoped, made using a pure graphite target, or doped, using multi-component targets made from a combination of graphite and silicon, silicon nitride, titanium dioxide, or silicon monoxide. These films were evaluated for their potential use in biomedical applications, including coatings for artificial joints, heart stents, and bronchoscopes. The films were characterized by Raman spectroscopy, atomic force microscopy, ball-on-flat tribometry, contact angle measurements, and spectrophotometry. Film thickness was determined by optical profilometry. Film adhesion was checked …

Mesophase Pitch-Based Carbon Fiber And Its Composites: Preparation And Characterization, Chang Liu

Masters Theses

The objective of this study is to investigate the relationship among process, structure, and property of the UTSI pitch-based carbon fibers and optimize carbon fiber’s mechanical properties through the stabilization process. Various analysis techniques were employed throughout these investigations which include the Scanning Electron Microscope (SEM), optical microscope, Dia-stron system, MTS, and ImageJ.

Several fiber process techniques including fiber spinning, stabilization, and carbonization were explored to determine the effect of the thermal process on the fiber yield, fiber diameter, the sheath-core structure of stabilized fibers, the pac-man and hollow core structures of carbonized fibers, and the resulting mechanical properties of …

Energy-Related Carbon Emissions In Ireland: Scenarios To 2020, Tadhg O'Mahony

Doctoral

The consumption of energy and related carbon emissions are a development challenge requiring analysis and policy insights. Current analysis of future change in Ireland relies on quantitative point forecasts within which accuracy is difficult to achieve. A scenario analysis approach has often been applied with the longer term but is also useful on shorter time-scales. This research applied a combination of decomposition analysis and scenario analysis to identify and analyse the driving forces of change in Ireland historically from 1990-2007 and in the future to 2020. The historical decomposition used the LMDI I technique and was further quantified to 2020 …

Composite Suspension For Formula Sae Vehicle, Reid Olsen, Andrew Bookholt, Eric Melchiori

Mechanical Engineering

This senior project report describes how a redesign of the 2008 Cal Poly Formula SAE vehicle's suspension components was conducted using carbon fiber components.

Mechanical Properties Of Carbon Nanotube/Metal Composites, Ying Sun

Electronic Theses and Dissertations

Carbon nanotubes (CNTs) have captured a great deal of attention worldwide since their discovery in 1991. CNTs are considered to be the stiffest and strongest material due to their perfect atomic arrangement and intrinsic strong in-plane sp 2—sp 2 covalent bonds between carbon atoms. In addition to mechanical properties, CNTs have also shown exceptional chemical, electrical and thermal properties. All these aspects make CNTs promising candidates in the development of novel multi-functional nanocomposites. Utilizing CNTs as fillers to develop advanced nanocomposites still remains a challenge, due to the lack of fundamental understanding of both material processing at the nanometer scale …

Feasibility Study Of Lightweight High-Strength Hollow Core Balsa-Frp Composite Beams Under Flexure, Kevin O'Neill

Electronic Theses and Dissertations

The United States of America's Military, more specifically the Army, has since the late 1990's had a vested interest in the development of super-lightweight, portable, short-span composite bridge and decking components to replace aging heavy metal-alloy machine driven modular systems. The following study looks at the feasibility of using balsa wood as the structural core material in fiber reinforced polymer (FRP) wrapped hollow-core composites in short-span bridge applications. The balsa provides shear resistance and the FRP the flexural resistance, resulting in extremely high strength-to-weight and strength-to-depth ratios. Several scaled short span specimens were constructed and tested using a variety of …

Strong Competition Between The Delta L And Delta T-C Flux Pinning Mechanisms In Mgb2 Doped With Carbon Containing Compounds, Shaban R. Ghorbani, Xiaolin Wang, Md S. Hossain, Qiwen Yao, S X. Dou, Sung-Ik Lee, K C. Chung, Y K. Kim

Australian Institute for Innovative Materials - Papers

The transport and magnetic properties of 10 wt % malic acid and 5 wt % nanocarbon doped MgB₂ have been studied by measuring the resistivity (p), critical current density (j_c), connectivity factor (A_F), irreversibility field (H_irr), and upper critical field (H_c2). The pinning mechanisms are studied in terms of the collective pinning model. It was found that both mean free path (δl) and critical temperature (δT_c) pinning mechanisms coexist in both doped MgB₂. For both the malic acid and nanocarbon …

Computational Intelligence For Carbon-Centric Computing, John Fulcher

Faculty of Engineering and Information Sciences - Papers: Part A

The focus of this paper is twofold: firstly we make a case for the use of Computational Intelligence (CI) techniques in the modelling and/or prediction of global weather, CO2 emissions, climate change and similar endeavours. CI exploits processes found in Nature, albeit by way of software simulations on digital computers (i.e. in silico), and excel in particular at pattern recognition and/or classification. Moreover, they are characterized as being non-algorithmic, bottom-up, data-driven, and learn-by-example. The second focus of this paper is to propose the use of carbonrather than silicon-based computing, specifically in the form of DNA (or molecular) computing. Notwithstanding the …

High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou

Faculty of Engineering - Papers (Archive)

Hollow-structured α-Fe₂O₃/carbon (HIOC) nanocomposite with a high surface area of around 260 m² g⁻¹ was synthesized by a one-step, in situ, and industrially-oriented spray pyrolysis method using iron lactate and sucrose solution as the precursors. The small α-Fe₂O₃ nanocrystals were highly dispersed inside amorphous carbon to form a carbon nanocomposite. Electrochemical measurements showed that the carbon played an important role in affecting both the cycle life and the rate capability of the electrode. The HIOC composites showed the best electrochemical performance in terms of high capacity (1210 mAh g^{−1 …}

Correlation Of Nanoindentation-Induced Deformation Microstructures In Diamondlike Carbon Coatings On Silicon Substrates With Simulation Studies, Ayesha J. Haq, Paul G. Munroe, Mark Hoffman, Phil J. Martin, Avi Bendavid

Faculty of Engineering - Papers (Archive)

The effect of the presence of diamondlike carbon coatings deposited on (100) Si substrateson the deformation mechanisms operating in the silicon substrate during contact loadinghave been investigated by both cross-sectional transmission electron microscopy andmodeling of the stresses generated beneath the indenter tip. The observed subsurfacemicrostructures were correlated to the Tresca shear stress and the hydrostatic stressgenerated in the silicon substrate beneath the indenter tip. The presence of the coatingaltered the stresses generated in the substrate, and changed the deformation mechanismfrom one of principally phase transformation in uncoated Si to predominantly dislocationmotion in the silicon substrate for the diamondlike C¿Si system. …

Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou

Faculty of Engineering - Papers (Archive)

Flexible silicon/single-walled carbon nanotube (Si/SWCNT) composite paper was prepared using the pulsed laser deposition (PLD) method to deposit Si onto SWCNT paper. In the composite, Si mainly shows nanoworm-like morphology. Increasing deposition time results in an increased amount of Si microspheres. Electrochemical measurements show that the capacity of the composite paper is improved by the presence of Si. The Si/SWCNT composite with only 2.2% Si shows a capacity of 163 mA h g⁻¹ at a current density of 25 mA g⁻¹ up to 50 cycles, which is more than 60% improvement of the capacity of pristine CNT paper. …

Controlled Synthesis Of Polyaniline Inside Mesoporous Carbon For Electroanalytical Sensors, Shenmin Zhu, Jiajun Gu, Junping Dong, Xinye Liu, Zhixin Chen, Chenxin Chen, Di Zhang

Faculty of Engineering - Papers (Archive)

A novel electroanalytical system was developed using polyaniline (PANI) functionalized ordered mesoporous carbon (CMK-3). Hydrophilic surface modification of CMK-3 is necessary and enables monomers to penetrate the pore channels of CMK-3, which makes it possible for the formation of PANI layers inside the pores of CMK-3 via in situ polymerization. The structures of the surface-modified ordered mesoporous carbon (m-CMK-3) and the PANI functionalized composites (CMK-PANIs) were characterized by X-ray diffraction, thermal gravimetric analysis, Fourier transform-infrared spectroscopy, transmission electron microscopy, and N₂ adsorption measurements. The catalytic effect of the resultant CMK-PANI composite electrodes with various PANI loadings on the hydroquinone/quinine …

Development Of A Family Of High Strength Low Carbon Microalloyed Ultra-Thin Cast Strip Products Produced By The Castrip® Process, Chris R. Killmore, Kristin R. Carpenter, Harold R. Kaul, James G. Williams, Daniel G. Edelman, Peter C. Campbell, Walter N. Blejde

Faculty of Engineering and Information Sciences - Papers: Part B

The manufacture of high strength strip products in strip thicknesses less than 1.5mm is very challenging for the conventional hot and cold rolled processing routes. A range of Nb and Nb/V microalloyed steels have been successfully strip cast by the CASTRIP process enabling the development of a range of high strength Ultra-Thin Cast Strip (UCS) products. It was found that the CASTRIP process fully exploits the strengthening potential of the low C-Mn-Nb-(V) alloy design system. Substantial strengthening by microstructural hardening was provided by Nb. Retention of Nb and V in solid solution in hot rolled coils enabled further strengthening by …

Theoretical Analysis Of Stresses In A Lithium Ion Cell, Sindhuja Renganathan, Godfrey Sikha, Shriram Santhanagopalan, Ralph E. White

Faculty Publications

A mathematical model to simulate the generation of mechanical stress during the discharge process in a dual porous insertion electrode cell sandwich comprised of lithium cobalt oxide and carbon is presented. The model attributes stress buildup within intercalation electrodes to two different aspects: changes in the lattice volume due to intercalation and phase transformation during the charge/discharge process. The model is used to predict the influence of cell design parameters such as thickness, porosity, and particle size of the electrodes on the magnitude of stress generation. The model developed in this study can be used to understand the mechanical degradation …