Metal foams and wire meshes are open cell structures with low weight and density, high permeability and high thermal conductivity which make them attractive for a wide range of industrial applications involving fluid flow and heat transfer. In this study, the effect of natural convection, radiation and heat transfer enhancement of metal foams and wire meshes of 10 and 40 PPI (pores per inch) heat exchangers were examined and compared for different heat exchanger orientation, coolant flow rate and atmosphere temperature. Thermal spray coating processes were also used in development of a new class of high temperature stainless steel heat exchangers. Stainless steel wire mesh heat exchangers were prototyped by connecting the tube to the wire mesh using wire arc thermal spray coating. Thermal spray coating provided efficient connections between the wire mesh and the tubes’ outer surface, and has potential to replace expensive brazing or other metal connection techniques.

Starch-derived bioplastics are an inexpensive, renewable and environmentally-friendly alternative to traditional petroleum-based plastics. Proteins secreted by Ophiostoma ulmi, were investigated for their application in bioplastic product. Proteins were isolated from fungal cultures by anion exchange chromatography and used to treat starch. Subsequently, plastic films were generated by solution casting, with glycerol as plasticizer. Tensile strength of the films was found to increase significantly compared to the control. The relative water holding capacity of the treated starch also decreased dramatically. Attempts to identify fungal proteins by MALDI-TOF MS/MS did not result in positive matches, mainly due to lack of fungal sequence information. Additionally, the effect of non-specific proteins resulted in a modest increase in tensile strength and a slightly greater effect on water absorption. Proteins secreted by O. ulmi were therefore implicated in improving properties of starch-based plastics. Investigation into the role of an extracellular polysaccharide is also suggested.

High strength-to-weight nanocrystalline alloy enabled conductor (NEC) prototypes were successfully developed by reinforcing an oxygen-free copper core material with electrodeposited cobalt phosphorus (CoP) coatings. A rule of mixtures approach was utilized to design the NEC prototypes to meet materials performance indices. Three unique NEC prototypes were produced with CoP coatings composed of alternating nanocrystalline (11 nm) and coarse-grained layers. The tensile properties were dependant on the coating microstructures, with tensile strengths of 1000 MPa, 970 MPa, and 900 MPa, respectively, and corresponding tensile elongations of 4.6%, 6.1%, and 10%, respectively. The electrical conductivity of the NEC prototypes was ~58 %IACS (resistivity of ~2.96 µΩ-cm). The rule of mixtures approach effectively predicted the tensile strength and conductivity. The NEC samples were significantly stronger than the incumbent high-strength aerospace conductor material, Be-Cu alloy CS95, which exhibits a tensile strength of only 655 MPa and conductivity of 63 %IACS.

Multi-walled carbon nanotubes (MWCNTs) were successfully coated with two different pseudocapacitive polyoxometalates (POMs) (SiMo12O40-4 (SiMo12) and PMo12O40-3 (PMo12)) via “Layer-by-Layer” deposition. Even with merely a “single-layer” of POM, the modified nanotubes exhibited more than 2X increase in capacitance compared with that of bare nanotubes. To further improve their electrochemical performances, the deposition sequence of the POM layers was adjusted to form “alternate layer” coating to modify MWCNT. A synergistic effect on the capacitance and kinetics was observed with the alternate layer coatings. X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM) also proved the successful coating of POMs on MWCNTs. The potential-pH relationship provided important insights in terms of the deposition mechanism and suggested that the bottom layer close to the electrode substrate was the dominating layer in alternate layer coated MWCNT electrodes.

Purification of metallurgical grade silicon (MG- Si) by a combination of solvent refining and physical separation has been studied. MG-Si was alloyed with iron and solidified under different cooling rates to grow pure Si dendrites from the alloy. The Si dendrites and FeSi2 that were formed after solidification were then separated by a gravity-based method. The separation method relies on significantly different densities of Si and FeSi2, and uses a heavy liquid with specific gravity between the two phases to float the former on the surface of a heavy liquid, while the latter sinks to the bottom. The effect of particle size and cooling rate on the Si yield and separation efficiency of the Si phase was investigated. The floated Si particles were further purified by removing the physically adherent Fe-Si phase, using an acid leaching method. Analysis of the produced silicon indicates that several impurity elements including P and B can be efficiently removed using this simple and low-cost technique.

Rosiglitazone (RSG) is an insulin-sensitizing drug used to treat Type 2 Diabetes Mellitus (T2DM). Clinical trials show that women taking RSG experience more limb fractures than patients taking other T2DM drugs. The purpose of this study is to understand how RSG (3mg/kg/day and 10mg/kg/day) and the bisphosphonate alendronate (0.7mg/kg/week) alter bone quality in the male, female and female ovariectomized (OVX) Zucker fatty rat model over a 12 week period. Bone quality was evaluated by mechanical testing of cortical and trabecular bone. Microarchitecture, bone mineral density (BMD), cortical bone porosity, bone formation/resorption and mineralization were also measured. Female OVX RSG10mg/kg rats had significantly lower vertebral BMD and compromised trabecular architecture versus OVX controls. Increased cortical porosity and decreased mechanical properties occurred in these rats. ALN treatment prevented these negative effects in the OVX RSG model. Evidence of reduced bone formation and excess bone resorption was detected in female RSG-treated rats.

Cellulose is a potential source of nano-material not only because it possesses excellent mechanical and optical properties, but also because it is environmentally benign. In this study, nanofibres derived from wheat straw, an agriculture residue, was utilized in producing flexible and optically transparent nanocompostie films. The composites were produced using a bi-phase impregnation technique that coats the dried nanofibre films with clear polyurethane acrylate resins using UV radiation induced curing. The nanocomposite films thus produced possess excellent tensile properties (161MPa in strength and 9GPa in Young’s Modulus), superior thermal stability (above 300°C), low coefficient of thermal expansion (8-9ppm/K), good light transparency (80%), excellent flexibility and abrasion resistance. These nanocomposite films are aimed to replace the conventional glass substrates made in batches to a polymer based substrates that can be efficiently produced in a roll-to-roll process for the base of the future flexible flat panel displays.

Experiments were conducted to investigate the potential of using a quench and self-tempering heat treatment process with AISI 1117 steel to satisfy the mechanical properties of ASTM A 706 rebar. A series of quenching tests were performed and the resulting microstructure and mechanical properties studied using optical microscopy, microhardness measurement, and tensile tests. The presence of martensite throughout the samples contributed to the enhanced strength and strain-hardening ratio (tensile to yield strength) of the material. The experimental results showed that AISI 1117 is capable of meeting the ASTM standard. In addition to the experiments, a computer model using the finite difference method and incorporating heat transfer and microstructure evolution was developed to assist in future optimization of the heat treatment process.

The effect of annealing conditions on the microstructure evolution of CVD nickel was investigated systematically in the present study by differential scanning calorimetry, optical microscopy and transmission electron microscopy (TEM), upon both ex-situ and in-situ annealing. TEM observation revealed the as-deposited CVD nickel possessed a bi-modal grain structure, with large columnar grains embedded in nanocrystalline matrix. Ultrafine and nano growth twins were present as well as multiply twinned grains with five-fold symmetry. Microstructure observation upon annealing showed that grain growth did not occur until annealing at 400ºC. Detwinning was observed at 400ºC and higher temperatures. The ultrafine and nano twins tended to transform into dislocation cell structures and this phenomenon was driven by the excess free energy associated with the high density of grown-in twin boundaries. The five-fold twinned grains were found to be thermally stable up to 600ºC. The hardness was observed to decrease with increasing annealing temperature.

A self-aligning nanostencil mask is used to fabricate circular features of tin, indium and silver on an atomically clean Si(001) substrate. The shadow mask limits deposited material to areas under openings in the mask, leaving adjacent clean areas for material to diffuse. STM, SEM and AFM have been used to study the surface diffusion of these metals in UHV. The diffusion of tin is relatively limited in comparison to the other metals. Indium forms metal islands that dissolve over time and contribute to the spreading of a surrounding single layer film. Lastly, silver forms a film that spreads even in the absence of metal islands.