Engineering Commons^™

Growth Of Mc3t3-El Pre-Osteoblasts On Borate Containing Glasses & Growth Of Osteoblastic Cells On 13-93 Glass Scaffolds, Agatha Dwilewicz

Opportunities for Undergraduate Research Experience Program (OURE)

Three borate-based glasses, compositions designated 1B, 2B, and 3B, with B₂0₃ levels of 15, 31, and 46 mole percent (Table 1), respectively, were tested for their effects on the growth of MC3T3-El mouse pre-osteoblastic cells under physiological fluid conditions. Silicate type 45S5 glass was used as a control for comparison. Independently, the biocompatibility of recently developed silicate-based porous 13-93 bioactive glass scaffolds was tested; Saos-2 human osteosarcoma cell line was used. Tests performed for the two studies included: contact assays of cell growth at the glass interface, chemical analysis of borate released into the culture medium, quantitative …

Development Of Single Chamber Solid Oxide Fuel Cells With Porous Samaria Doped Ceria Electrolytes, Nathaniel Goss

Opportunities for Undergraduate Research Experience Program (OURE)

Single chamber solid oxide fuel cells generate electricity using hydrogen and hydrocarbon fuel mixed with oxygen at intermediate temperatures (400-800°C) without using seals to separate the gases. A single-chamber solid oxide fuel cell was fabricated with a porous samaria doped ceria (SOC) electrolyte, nickel oxide anode, and a lanthanum strontium cobalt iron oxide (LSCF) cathode. Instead of separately sintering the different components at different temperatures, the electrolyte and electrodes were co-sintered at 1100°C. The porous SOC electrolyte approached 84% theoretical density when sintered at 1100° C. The fuel cell had a maximum open circuit voltage of .65 V at 550°C. …

The Reduction Of Dielectric Constant By Shaped Porosity, Weiping Cai

Opportunities for Undergraduate Research Experience Program (OURE)

In multi-layer circuits, the reduction of the dielectric constant in substrate materials is becoming increasingly important, as the heat emission of the circuits increases with an increasing number of layers. One way to achieve a lower dielectric constant is to create porosity in the material. In this project, two types of substrate samples were made with coin-shaped porosity. One had holes of 8.0mm in diameter, and the other had holes of 2.5mm in diameter. The total vacuum area was 250mm², or 7.7% of the total area, in either case. It was hoped to discover a relationship between aspect …

Solubility Of Red Phosphorous In Lead, Sean E. Walker

Opportunities for Undergraduate Research Experience Program (OURE)

The determination of the solubility of red phosphorus in lead can be used to produce a plot of the solubility with respect to temperature and pressure. The plot is produced with experimental data, activity determination from present thermodynamic data, and compilation of the two sets of data into the semi-regular solution format. A lead-phosphorus solubility diagram is necessary to determine the amount phosphorus that will be absorbed by lead and will remain unreacted in a given process.

Tape Casting For Lead Zirconate Titanate (Pzt) Multilayer Composites, Jane L. Cochran

Opportunities for Undergraduate Research Experience Program (OURE)

Tape casting is a process for making thin flat ceramic pieces by using a scraping blade or "doctor blade" to evenly coat a smooth surface with a slip[ 1 ]. The slip is a mixture of powder, solvent, binder, and other organics which result in a paint like consistency after they are mixed.

The tapes is cast into thicknesses ranging from 1 to 50 mils on a smooth surface , which is usually made of Mylar, and left to dry.

Once the tape has dried it can be cut into several different shapes and sizes, and then fired to form …

Mechanical Properties Of Whisker-Reinforced Cordierite Glass Matrix Composites, John R. Dillingham

Opportunities for Undergraduate Research Experience Program (OURE)

The development of a whisker-reinforced ceramic matrix composite has been shown to be a reasonable method of achieving improved mechanical properties for ceramic materials. In this work a cordierite matrix was reinforced with 20vol% of silicon carbide whiskers. The mechanical properties of this composite were compared to those of the nonreinforced cordierite matrix. As would be expected, the whisker- reinforced matrix showed a significant improvement in mechanical properties.

The specimens used for testing were processed by hot-pressing in an argon atmosphere using a graphite die coated with boron nitride. Hot pressing was carried out at 950°C for the pure matrix …

Solidification Modeling Of Centrifugal Casting, Stephen M. Lane

Opportunities for Undergraduate Research Experience Program (OURE)

This paper describes the methodology used to estimate the solidification time of castings produced by processes in which normal thermal analysis cannot be used, such as centrifugal casting. This methodology utilizes the relationship between microstructure, in particular secondary dendrite arm spacing (SDAS), and freezing time. Using this method it is shown that position within the casting and casting geometry affect the SDAS and freezing time. However, the SDAS did not vary across the wall section due to differences in filling pattern compared to sand casting. Further research is necessary to determine filling pattern effects on microstructure.

Electrochemical Technique For Evaluating Surface Area Of A Treated Copper Foil, Gregory Lea

Opportunities for Undergraduate Research Experience Program (OURE)

In order to increase the strength of copper foil bonded to a polymeric substrate material, a dendritic layer is electrodeposited onto the foil. Treating the foil in this manner causes its surface to be rough and porous, thus providing for better penetration of the adhesive and a greater surface area for bonding. The process is particularly helpful in the manufacturing of printed circuit cards, due to the added bond strength which greatly enhances the durability of the printed circuit cards.

Influence Of Pattern Geometry And Pouring Temperature On Fluidity In The Expendable Pattern Casting Process, Diego Rodriguez Risco

Opportunities for Undergraduate Research Experience Program (OURE)

This report is an extension of the paper "Influence of Pattern Geometry and other Process Parameters on Mold Filling in the Aluminum EPC Process", by Yuan Sun, Hai-Lung Tsai and Donald R. Askeland (2). The increase in fluidity in the expendable pattern casting (EPC) process with pattern perimeter, volume to surface area (V/A) ratio, and pouring temperature was studied for a 700°C-900°C temperature range and for both aluminum and cast iron.

A Study Of High Temperature Oxidation Resistance Of Plasma Treated Nb-Ti-Al Alloys, Roderick R. Rowland

Opportunities for Undergraduate Research Experience Program (OURE)

The effect of plasma treatment on the oxidation behavior of Ti-22Al-27Nb (atomic%) has been studied. The alloy, cast as an ingot by triple VAR and worked to a billet, was cut into smaller samples and oxidation plasma pre-treated. Oxidation plasma pre-treatments were conducted at four ambient temperatures: 25°C, 200°C, 400°C, and 500°C. Both the untreated and plasma pre-treated samples were oxidized at 700°C and 1000°C for one hour, in a muffle furnace. The oxidation behavior of the samples led us to do an extended oxidation of 100 hours at 700°C. The 200°C plasma pre-treated samples showed a definite leveling out …

Cyclodextrin Stationary Phases For The Gas-Solid Chromatographic Separation Of Hydrocarbons, Chris A. Monge

Opportunities for Undergraduate Research Experience Program (OURE)

Cyclodextrin, bonded to silica gel and used as a gas-solid chromatographic stationary phase provides a practical and efficient means for separating a wide variety of C₁-C₇ hydrocarbons at ambient to elevated temperatures. Conditioning the columns at high temperature (300°C) for several hours increased efficiency and resolution. The adsorption of these light hydrocarbons involves a multiple retention mechanism. Evaluation of the columns and an analogous silica gel column with hydrocarbon standards is reported. Capacity factors and chromatograms are presented for these GSC stationary phases.

Stimulation Of Amorphizing Reactions In Co-Si Multi-Layers, Jeanne K. Jackson

Opportunities for Undergraduate Research Experience Program (OURE)

Co-Si multi-layer specimens do not normally amorphize. To possibly stimulate amorphization, Ti was added by evaporation and the specimens were annealed at 300 and 400 degrees Celsius. The results showed that amorphization occurred at 400 degrees Celsius in the presence of Ti, but did not occur at 300 degrees Celsius. Further research would be necessary to conclude whether the amorphization was stimulated by the addition of Ti or the temperature increase.

Measuring Hydrogen In Galvanized Steels, Timothy O'Hearn

Opportunities for Undergraduate Research Experience Program (OURE)

There has been much investigation in the past concerning ways to eliminate the embrittling effects of hydrogen in galvanized steel components. Such galvanized parts are used extensively in the automotive industry. One solution that is commonly used is to anneal the galvanized parts at approximately 200 degrees Celsius for 4 to 24 hours. This annealing process does restore the ductility. However, very few if any experiments have been done to measure the amount of hydrogen released and the temperature dependence of the hydrogen release. This investigation is part of an on going effort to measure the hydrogen released from galvanized …

The Electrochemical Characterization Of Ferrocene As A Guest Molecule In The Presence Of Ss-Cydodextrin, Anne T. Roberson

Opportunities for Undergraduate Research Experience Program (OURE)

This experiment involves the development of electrochemical experimental methods for the determination of the oxidation/reduction potentials of a guest ferrocene complex (C₁₀H₁₀Fe) hosted by ß-cyclodextrin. The project was conducted so that the specific interaction of two molecules forming a unique inclusion compound can be used as a model for rapid analysis of other small molecules. In principle, the study is based on the expected equilibrium interaction of the iron compound with ß-cyclodextrin resulting in a complexed and an uncomplexed species equilibrium. The project's experimental objective is to determine if the redox potentials of both complexed and …