Journal of Undergraduate Materials Research

Permanent URI for this collection

https://hdl.handle.net/10919/90231

Browse

Now showing 1 - 13 of 13

Biocompatibility and Hardness of Ti-Hf and Diamond-like Carbon Coatings for Orthopedics
Kuhn, Stephanie (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
Every year, about 300,000 total hip replacement (THR) surgeries are performed in the United States.The typical lifespan of an implant ranges between 10 and 20 years, with implant failures largely due to materials issues such as biocompatibility, wear, corrosion, and premature stress failures.The objective of this research is to examine the feasibility of using a new class of materials, namely Ti-Hf alloys and low friction diamond-like carbon (DLC) coatings, for improving the performance of orthopedic devices.Biocompatibility and hardness tests were performed, which showed Hf did not adversely affect the biocompatibility of Ti and that the DLC coating did not adversely affect the biocompatibility of the Ti-Hf alloy.Furthermore, the biocompatibility of the Ti-Hf alloy was comparable to that of Ti-6Al-4V.The research was done as a collaborative effort between the College of Engineering and the School of Veterinary Medicine at the University of Wisconsin – Madison and NASA Glenn, Cleveland, OH.
Characterization of Electrolessly Plated Graphite Foams with Particle Additions
Asaro, Michael; Mueller, Jennifer; Dykema, Patrick (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
With a low density and high bulk thermal conductivity, graphite foams are ideal for thermal management systems such as computer heat sinks, radiators, and heat exchangers.Previous work has shown it is possible to improve the foams performance by opening the porosity with nanoparticle additions in the foams precursor, an oil based mesophase pitch.[1] The open porosity allows more fluid, such as air or water, to pass through the foam and carry heat away.The original study, performed by Jennifer Mueller at Oak Ridge National Labs (ORNL), considered the concentrations of nanoparticle’s used.The present study looked to determine the effects of using different types of nanoparticles at a range of sizes from the nano- to micro- level.The study began by adding, respectively, silver, ceria, alumina, tungsten, and nickel to different batches of mesophase pitch at a single weight percent concentration to create graphite foams with a significant amount of continuous porosity.The pitch was foamed, carbonized, and graphitized.The final foam products were then measured in a variety of ways including thermal conductivity, permeability, and scanning electron microscope (SEM).As a side project, an electroless copper plating solution was passed through the foams to determine if a continuous and uniform copper coating could be built up.The copper coating that was eventually obtained coated the foam walls without filling the open porosity and may help to increase the foams solderability, strength, durability, and corrosion resistance.
DISCOVERIES AND BREAKTHROUGHS INSIDE SCIENCE: Bringing science from the laboratory to the living room
Martin, Lane; Hickey, Diane; Poquette, Ben; Jones, Kevin; Floro, Jerrold (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
Have you ever kicked back to watch your favorite sciencebased TV programming and had the thought, “That’s not so hard, I could do that.” With the help of a partnership between the National Science Foundation (NSF), the American Institute of Physics (AIP), 19 professional scientific organizations, including the Materials Research Society (MRS), and Ivanhoe Broadcast Network, Inc., you might have the chance to be a science-star for a day and to bring your work in the laboratory to the living rooms of millions of American television viewers.
The Effect of Cornstarch Levels on the Surface Quality of Extruded Soy Protein Plastic
Ziolkowski, Evan (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
The ratio of soy protein isolate to cornstarch was studied in the extrusion of four different formulations of soy protein plastic in order to qualitatively examine the surface quality upon extrusion.Levels of glycerol and moisture were constant across all samples, and no other additives were used in the mixtures.Mixtures were made using a planetary mixer, and then extruded using a single-screw extruder equipped with a 10.16 centimeter sheeting die with a 0.152-centimeter opening.The surface of the extruded plastic became smoother with increasing starch content, but the processability became too difficult with very high starch levels.
Evaluation of Bearing Steel Corrosion in Oil Contaminated with Synthetic Seawater
Christoffersen, Brandon (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
Lubricant systems in military aircrafts, operating in marine environments, experience corrosion due to seawater contamination.In particular, low chromium martensitic bearing and gear steels are susceptible to pitting corrosion attack in seawater-contaminated lubricants.Therefore, the corrosion performance of two advance bearing steels was assessed in this study.The steels were immersed in oil solutions and the corrosion results were analyzed as a function of seawater content and time.Optical image analysis was used to measure the pit density/size/distribution and an optical profiler was used to measure pit depth.It was found that while the pit surface fraction (pit surface area/total area) and pit depth increased with seawater content and time, the actual chloride content in the oil might have made a greater contribution to the corrosion damage.
Journal of Undergraduate Materials Research, Vol. 3 (2008)
(Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
The Journal of Undergraduate Materials Research (JUMR) is a student-run scientific journal dedicated to research performed by students in materials science and related fields. The primary goal of this journal is to provide a platform for undergraduate researchers to publish their work. The secondary goal of this journal is to provide opportunities for undergraduates to practice their communication skills and gain experience working with reviewed publications. The third issue of the Journal of Undergraduate Materials Research continues to be a product of collaborative effort between the Virginia Tech Department of Materials Science and Engineering and the Virginia Tech Department of English. This issue features articles and student research focusing on a variety of subjects in materials science and engineering. The works within this issue represent students from schools including Boise State University, Savannah State University, The University of Illinois, the University of Kentucky, the University of North Carolina at Charlotte, Virginia Tech, and the University of Wisconsin-Madison.
Material Advantage Students Visit Washington
Niswonger, Tricia (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
The Congressional Visits Day (CVD), sponsored by The Federation of Materials Societies (FMS) and the Material Advantage Student Program, is an event that gives students and faculty an exciting opportunity to visit on Capitol Hill with members of the U.S. Congress and congressional staffers from their own states.The 2007 event was held March 19–20.The goal of the event is to educate Congress about the importance of research in materials science, engineering, and manufacturing and the need to increase federal R&D funding.Approximately 60 Material Advantage students and faculty from 11 schools from around the country journeyed to Washington to participate.
Optical Properties of an Electrochromic Device Based on Poly (aniline 2-sulfonic) acid (PASA) Film, Formed by Ionically Self-Assembled Multilayers (ISAM) Technique
Montazami, Reza (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
A new ElectroChromic Device (ECD) was designed and constructed based on Ionically Self Assembled Multilayers (ISAM) technique, in which oppositely charged polymers are used to construct films of multiple layers.The ECD device proposed and studied in this work was based on Poly (aniline 2-sulfonic) acid, (PASA), as the active electrochromic polyanion, and Poly (allylamine hydochloride), (PAH), as the inactive polycation.Cyclic Voltammetry (CV) technique was employed to study redox properties of the polymer film and to help to determine the operating voltage of the device.It was determined that the PAH/PASA ECD has two redox states between –700mV and +700mV.The ECD with 40 bilayers demonstrated dark green to light brown to dark gray electrochromism, in the –700mV to +700mV window.The major transmittance occurred at –600mV (dark green) and +600mV (dark gray).The ECD in the relaxed state, i.e. no voltage applied, is light brown.At –600mV, in visible spectrum, the highest contrast (∆T=27%) appeared at approximately 690nm (dark green) and at +600mV the highest transmittance in visible range was a broad range between approximately 600nm to 710nm.
Percolation of Fibrous and Bimodal Fillers in Thermoreversible Gelcast Aluminum Oxide
Bond, Kristina (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
A novel pore morphology was developed by addition of fugitive fibers to a thermoreversible gel slurry to induce pores in alumina (Al2 O3 ) samples.Through density measurements by the Archimedes’ method and SEM images the percolation threshold for fibers with aspect ratios of 37 and 120 was found to be less than 1 vol% fibers.Introducing two spherical fillers with different diameters (3.5:1 diameter ratio) to create bimodal filler has a small effect on the percolation threshold, if any.More research is needed to understand the effect of bimodal fillers on the pore morphology.
Ruthenium Coordination Chemistry: Implications for Directed Carbon Nanotube Assembly
Younts, Thomas (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
Ruthenium coordination chemistry is studied for its usage as a building block for constructing supramolecular coordination complexes.Our laboratory focuses on how nanometer sized ruthenium structures interact with single walled carbon nanotubes (SWCNTs) with implications for directed nano-structure assembly.Understanding aspects of carbon nanotube assembly involves synthesizing ruthenium coordination complexes with various morphological and electrostatic properties.For example, various ruthenium dendrimers, each of which differs in shape and overall cationic charge, can be synthesized.Progress towards synthesizing a ruthenium trimer is reported.The central unit to the trimer, [Ru(phendione)2 phen]2+, was successfully created in high purity.[Ru(phen ) 2 phendiamine]2+, the peripheral monomer implemented in trimer synthesis, was not attained.However, precursor to the peripheral unit, [Ru(phen)2 phendione]2+, was synthesized.Since ruthenium monomers are built from various diimine ligands, syntheses of these ligands are also presented.Taken together, we possess half the starting material needed to create the trimer that will be utilized for carbon nanotube aggregation studies.
Solar Houses: You know you want one
Pritchard, Jessica (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
Amidst an unceasingly intricate political agenda lies what many consider a grave and often ignored issue:global warming.It would be naïve to overlook the current international political and financial demands, but few can refute global warming’s ever-increasing presence looming on the horizon.Fortunately, technological developments have brought about more affordable alternative energy sources, though most still require a fairly steep investment.I stress the term investment because alternative energy sources aren’t something you can purchase with those ten hours of overtime last week, but thinking in the long-term, imagine the benefits that will come from your green steps into the future.
Statistical Analysis of Impedance Data for Jet Turbine Oil Additives
Luke, Matthew (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
A gold, parallel-plate capacitor test cell was used to make electrochemical impedance spectroscopy (EIS) measurements on high resistivity gas turbine engine oil as a function of the oil additive type.The additive effects on the EIS response were determined by analyzing ester-based basestock oil mixed with a single additive.This work was performed for four different additives:antioxidant, metal deactivator, anti-wear, and extreme pressure.Multiple measurements were made for each basestock-single additive mixture.To determine whether the EIS response of each additive showed a significant difference, statistical analysis was performed on the data using a student’s t-test.Low-frequency data showed the largest difference in additive responses.Statistical analysis showed that the extreme pressure additive has the greatest effect on oil impedance.Mixtures of antioxidant and metal deactivator additives did not show interaction.
Structural Assessment of an Internal Fixation System for a Forearm Long Bone Mid-shaft Fracture
Woody, MyKal (Virginia Tech Department of Materials Science and Engineering, 2008-03-20)
A novel low cost manufacturing method for bone replicas is developed in order to provide cross sectional geometry for 3-D modeling.A Finite Element Analysis (FEA), based on this geometry, is used to predict stress distributions in the radius with and without an internal fixation device attached.The changes in stress distribution under tensile and torsional loads are quantified and agree well with predictions in current literature where more expensive modeling techniques are used.Normal stresses near the radial cortex are seen to be higher with the fixation device, however stress gradients are substantially steeper resulting in lower tensile stresses with decreasing as radial distance.Shear stress minimum values increase with the presence of the plates and do not reverse direction as is the case with the un-plated radius.Stress shielding effects due to the plates and stress concentrations due to the holes are observed to significantly affect stress magnitude and distribution in the radius bone with a fixation device.The results from this research support the conclusion that fixation devices leave bones more susceptible to future injury.

Browse

Browsing Journal of Undergraduate Materials Research by Author "Eichelberger, Davis"

Results Per Page

Sort Options