The 16th Annual
NC State University
Undergraduate Research Symposium
Engineering and
Technology
Abstracts
Abstracts
are listed in alphabetical order by the last name of the corresponding author.
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Abrecht, David G. |
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Department(s): |
Wood and Paper Science |
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Research |
Hasan Jameel/Wood and Paper
Science |
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Title of Presentation: |
Effect of Cellulose Crystallinity Modification on Enzymatic Hydrolysis Rates |
The mercerization of
fully-bleached hardwood and softwood fibers was performed to examine the effect
of fiber crystallinity on enzymatic hydrolysis. Comparison
testing between hardwood and softwood was first carried out to determine major
differences between fiber classes. Fibers were mercerized at 0, 3, 5, 8, 12,
and 18% NaOH concentrations, washed to remove
causticity, and hydrolyzed with cellulase complex and
beta-glucosidase. Crystallinity
was measured by X-ray diffraction and an index was calculated based on Clark-Terford method. Hardwood and softwood fibers were then
refined for 1500 revolutions in a PFI mill, mercerized at the same
concentrations and hydrolyzed to determine the effect of improvements in fiber
surface area. Mass loss during hydrolysis was found to increase linearly with
reductions in crystallinity index at high
mercerization concentrations, but at low concentrations mass loss increased
much more rapidly. Mass loss during hydrolysis was found to correlate strongly
with the loss of mass during mercerization, despite correction to 1 oven-dry
gram of fiber before hydrolysis began. This suggests that crystallinity
is not the only factor affecting hydrolysis rates, or that changes in crystallinity may be a secondary effect. Refined samples
showed improvements over non-refined samples at low mercerization
concentrations but not at high mercerization concentrations, as expected.
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Attarian, Adam |
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Department(s): |
Electrical and Computer
Engineering |
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Research |
H. J. Trussell/Electrical
and Computer Engineering |
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Title of Presentation: |
The Feasibility of
Illuminant Estimation in Hyperspectral Images Using
Known Reflectance Values |
We examine the feasibility
of estimating the spectral characteristics of an illuminant from the reflectances of known objects. We determine the number of
known reflectances needed to make an estimate using lagrangian minimization and projection onto convex sets
(POCS). Working in a 31 dimensional space spanning 400-700nm, we find the
useful dimensionality to be substantially lower by examining the eigenvalues of the covariance matrix associated with the
known reflectances. Using basis functions based on
optical filters, we are unable to match the relatively non-smooth D65 daylight
illuminant, though believe that smoother spectral illuminants would provide
better results. The POCS method is discussed, and explanations presented for
the error in data fits.
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Belvin, Brian Griffin, Jennifer Reynolds, Viscuso, Addie |
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Department(s): |
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Research |
Ratna Sharma/Ag and Life Sciences |
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Title of Presentation: |
Semi-Automated System for
Enzymatic Production of Biodiesel |
Growing environmental and
national security concerns regarding diminishing fossil fuels have highlighted
the need for exploring renewable alternatives like bioethanol
and biodiesel. The goal of this research was to
design and build a system employing an environmentally friendly and
economically feasible conversion approach to produce biodiesel
from oil. Current methods of converting oil to biodiesel
involve harsh chemical catalysts in the oil-methanol transesterification
reaction leading to undesirable and environmentally harmful by-products. An
alternative conversion method, that requires in-depth investigation, involves
the use of whole cells or lipase enzymes as the catalyst. However, the cost of
producing and purifying enzymes poses a drawback for their use. Immobilizing
the enzymes allows their re-use thus making the process economically feasible
as well as environmentally friendly. This research investigated immobilization
of lipases as well as fungal cells to produce the needed enzyme. The fungus, Rhizopus oryzae (ATCC-34612) that
can be maintained on agar slants, was grown and immobilized on foam biomass
support particles (BSP) in liquid media. R. oryzae
continually produces lipases during growth, therefore reducing recurrent enzyme
purchase cost. However, cell immobilization resulted in several challenges
related to inhibition of growth by methanol, choice of media to promote lipase
production, growth conditions, low enzyme activity, and conversion rate thereby
hindering success. Immobilization of lipases, in calcium-alginate beads, to
induce transesterification revealed low transesterification rates. The results of this project
indicate that although a semi-automated biodiesel
production system would be suitable for use with immobilized cells or enzymes,
future studies on factors like increasing alcohol tolerance of the
microorganism involved, lipase activity and stability, source of the purified
enzymes, and effect of methanol on enzyme activity need to be explored for this
approach to be commercially successful.
|
Burton Jr., Ronald R. Krishnan, Arjun Shankar, |
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Department(s): |
Materials Science
Engineering Fiber Polymer Science |
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Research |
Tushar K. Ghosh/Fiber &
Polymer Science Richard J. Spontak/Materials Science Engineering & Chemical and Biomolecular Engineering |
|
Title of Presentation: |
Tailoring Properties of Electroactive Polymers Through Concentration of Midblock-Selective Solvent: |
The concentration of midblock-selective solvent has been shown to dramatically
affect the electrical and mechanical properties of poly[styrene-(ethylene-co-propylene)-styrene]
(SEPS) triblock copolymers. In this study, we
investigated the impact of replacing an aliphatic-rich mineral oil (MO) with a
more complex and biologically degradable oligomeric
solvent: vegetable oil (VO). Specimens containing mixed a mixed MO/VO solvent
starting at 40 wt% VO have been analyzed. Electrical stimulation tests measured
the areal strains achieved upon actuation and the
dielectric breakdown field of each sample. In addition, mechanical measurements
of tensile, compressive and hysteric stress elucidated the effect of solvent
type on the elastic modulus of the samples. Quantitative analysis of these data
revealed a direct impact on the elastic moduli of the
samples: an increase in the concentration of VO from 40 to 70% resulted in a
marked increase in the elastic modulus. The effect of solvent quality on electroactuation properties will also be presented.
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Chavis, Pickett,
Carrie Siddiqui, Jones,
Randall |
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Department(s): |
Biological and
Agricultural Engineering |
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Research |
Sanjay Shah/Biological and
Agricultural Engineering |
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Title of Presentation: |
Development and Evaluation
of a Pilot-Scale Biofilter/Heat Exchanger System
for Improvement of Livestock Air Quality |
Hog production is an
integral part of the economy in
|
Cline, Stephen W. |
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Department(s): |
Electrical and Computer
Engineering |
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Research |
Michael J. Escuti/Electrical and Computer Engineering |
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Title of Presentation: |
Optical Enhancement
Studies on Liquid Crystal Polarization Grating Projection Schemes |
As the demand for high
brightness, high contrast, portable video-display
devices becomes more prominent, new projector technologies must be developed to
overcome the inherent limitations of current technology. Projection displays based
on a novel switchable diffraction grating (called
Liquid Crystal Polarization Gratings, LCPGs) are one
of the most promising solutions, because it eliminates the need for polarizers. Since the operational principle of this novel
LC microdisplay is substantially different from all
previous LC on Silicon (LCOS) devices, a new optical subsystem must be
optimized for it. The focus of this research project is to improve the optical
efficiency and brightness of this novel projection display technology. The central
problem being solved is that while the diffractive microdisplay
works best with collimated light, the most relevant light sources are only
partially collimated. Therefore an optimized design of the lenses, prisms, and
aperture-stops is necessary to minimize light loss between the light source and
the microdisplay. Our approach to solving this is to
use the principles of optical engineering and the commercial ray-tracing
software TracePro(R) to collimate the light with as
few losses as possible. The system will be an advanced way of manipulating
light in a Schlieren projection system that will
enable a brighter and more power efficient device than the LC projection
display systems that are currently available.
|
Coleman, Leslie S. Berk, Lindsay K. Woock, Jeremy D. |
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Department(s): |
Materials Science
Engineering |
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Research |
Carl C. Koch/ Materials
Science Engineering |
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Title of Presentation: |
Bimetallic Armor Plate Fuel
Economy in Aircraft by Decreasing Drag |
The purpose of this senior
design project, sponsored by ATI Allvac, is to design
a bimetallic armor plate. The ultimate goal is to replace the current K12®;
dual phase armor plate, manufactured by Allegheny Technologies, with a lighter
weight and more cost efficient product. The armor plate was created by roll
bonding two metals created at Allvac’s facility to
protect military equipment from projectiles. The first metal was a 13-8 Mo Supertough®; stainless steel alloy and the second was a
modified M50 tool steel. The roll bonding was conducted at two austenizing temperatures, 2075ºF and 2200ºF, and
experienced two thickness reductions of 75% (final thickness ~¼ inch) and 50%
(final thickness ~½ inch). Ageing was performed at two temperatures, 1000ºF and
1050ºF, to evaluate effects on either material at different temperatures.
Samples roll bonded at 2200ºF experienced cracking and plate separation during
heat treatment while the samples roll bonded at 2075°F remained mostly intact.
Hardness testing and metallurgy was conducted on both as-rolled and heat
treated samples. The average hardness for the M50 side of the plate at heat
treatments of 1000ºF and 1050°F were 63.9 and 64.7 HRC, respectively. Hardness
values at heat treatments of 1000ºF and 1050°F were 42.2 and 41.9 HRC,
respectively, for the 13-8 Mo Supertough®; side.
Optical micrographs revealed a tempered plate martensitic
microstruture within austenite grain boundaries for
the 13-8 Mo Supertough®;, and a martensitic
matrix within austenite grain boundaries with small round carbides for the
modified M50. Further metallurgical investigations include Charpy
Impact testing, SEM analysis, and EDS to determine the carbides in the
microstructures. All data will be compiled to compare to the K12®; dual phase
armor plate to see if the designed bimetallic armor would be a suitable
replacement.
|
Denney, Jason L. |
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Department(s): |
Electrical Engineering |
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Research |
Michael J. Escuti/Electrical Engineering |
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Title of Presentation: |
Optimizing Liquid Crystal
Display Fabrication |
The focus of this research
project is to improve the fabrication of a unique diffraction grating called the
liquid crystal polarization grating (LCPG), a novel and an increasingly
important electro-optical element. The central problem to be solved is that
unwanted optical scattering results whenever the functional polymer known as a
photo-alignment layer does not properly align the liquid crystal after the
ultraviolet holographic exposure. This leads to decreased diffraction
efficiency, and most importantly, limits the smallest grating period for high
diffraction to just under nine micrometers (five microns or less is desired).
Our primary approach to solve this problem is to systematically vary the
exposure time and measure the light scattering vs. angle with the automated
dynamic light scattering measurement system I have built from scratch in the
previous summer. We are in the process of fabricating many comparable samples
with only one fabrication parameter different, in order to find the narrow
window within which the energy dose enables the photo-alignment layer to have
the maximum anchoring energy. An additional set of measurements will be
performed to characterize key electro-optical properties on the light
diffracted and create a library of data for various materials that will be a
significant contribution suitable for publication.
|
Dupor, Stevan M. |
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Department(s): |
Electrical and Computer
Engineering |
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Research |
Subhashish Bhattacharya/Electrical and Computer Engineering |
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Title of Presentation: |
Ethernet/IP Implementation
at the Network and Application Layer for a Power Electronics System |
The single chip Ethernet/IP
solution using the Freescale MC9S12NE64 16-bit
microcontroller is a critical component of a larger generic control system being
developed at the Semiconductor Power Electronics Center (SPEC) for power
electronic applications. Current systems for controlling large inverters and/or
converters in power electronics are very specific to the application being
addressed. Although real-time control has been obtained for particular
problems, the control hardware and its underlying software do not adapt well to
a system change. The prevalent method of providing user interface through a PC
parallel or COM port imposes certain system constraints. The Ethernet/IP
solution being developed by us would enable universal connectivity of any power
electronics system. Research work is primarily on the TCP/IP stack
implementation and the application layers for Ethernet/IP. An existing TCP/IP
freeware source code is taken as the base and modified to suit our system
requirements. These system level changes in the base code are done to enable
communication with the real-time control processor that does computations for
power control. Labview is the application layer
software used for this project. Virtual instruments (
|
Field, Ryan M. |
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Department(s): |
Electrical Engineering |
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Research |
Maysam Ghovanloo/Electrical
Engineering |
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Title of Presentation: |
Particle Swarm Optimization
for Tracking a Magnetic Dipole with Five Degrees of Freedom |
The purpose of this project
is to extend the technology utilized in the
|
Fox, Paul Gotchy, Justin Thorton, Jackson |
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Department(s): |
Materials Science and
Engineering |
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Research |
C.M. Balik/Materials
Science and Engineering |
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Title of Presentation: |
Increasing the Radiation
Resistance of Cold Applied Gel Sealing Technology |
This research examines cold applied
gel sealing technology for the insulation of electrical components in nuclear
power plants. The current PowerGel® used as a gel
sealant by Tyco Electronics is problematic as it undergoes crosslinking
under large doses of irradiation, becoming very viscous and losing its sealing
properties. The purpose of this research is to find a suitable replacement for
this polydimethylsiloxane (PDMS)-based PowerGel®. Based on the results of previous research, the
addition of phenyl groups is known to provide radiation stability. Five samples
of phenylated siloxane
fluids, ranging in phenyl content from 5% - 50%, have been irradiated at six
different doses in 25 kGy increments from 25 kGy –150 kGy. Measurement of
viscosity change as a function of dose is used to analyze the radiation
resistance of the gels. The miscibility of these fluids with a high molecular
weight vinyl terminated PDMS has also been tested to determine the feasibility
of creating a gel similar to the PowerGel®. It was
found that only gels with 5% phenyl content are miscible in the vinyl
terminated PDMS, and this is the only fluid that can be synthesized into a gel
without altering the chemistry. A gel using this fluid was synthesized which
displayed similar properties to the PowerGel®. Both
gels were irradiated at 150 kGy and analyzed. The
results of this analysis will be presented and discussed.
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Furst, Stephen, J. Brown, J. Adam M. Freeman, Carolyn M. Blankenship, Taylor M. |
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Department(s): |
Mechanical and Aerospace
Engineering |
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Research |
Andre Mazzoleni/Mechanical
and Aerospace Engineering |
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Title of Presentation: |
Lunar Hard-Lander Design,
Fabrication, and Drop Testing |
The lunar hard-lander concept is being developed as a means of robotically
surveying the Moon or other solar system bodies. The hard-lander
is capable of limiting payload acceleration to 1000 G’s during a 60 m/s impact.
The ability to impact at this speed makes a complex retromotor
and guidance system unnecessary. Our hard-lander
design uses a thick layer of aluminum honeycomb to protect an instrument
payload stowed inside. Aluminum honeycomb has a constant crush strength and an
extremely high crush strain, so during an impact it provides the payload with
an essentially uniform deceleration. As a result, there are no destructive
peaks of acceleration. Also, our design is spherical and, as a result, it can
survive an impact at any orientation. The payload is further housed in a rigid,
carbon fiber shell. A telescoping shaft extends out from the payload housing to
provide a corridor for the payload to escape through, even after the impact
deforms the energy absorber. Payload ejection will allow certain instruments
and spacecraft components to be in direct contact with the lunar regolith. The
entire diameter of the entire hard-lander is less
than 1.2 m and has a mass of about 30 kg. The payload module is designed so
that it will self-stabilize into a predetermined orientation after being
ejected via airbag from the energy absorbing material. To prove this concept,
we have created twelve test coupons and fired them from a compressed air cannon
to verify the dynamic crush strength of the aluminum honeycomb. Also, we have
built and tested mock-ups of the self-stabilizing payload and airbag ejection
system. Finally, we have created two prototypes in which we will mount an
accelerometer. In the coming weeks we will drop test our prototypes from 500 ft
to verify the crush model for a spherical energy absorber.
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Going, Ryan W. |
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Department(s): |
Electrical Engineering |
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Research |
Michael J. Escuti/Electrical Engineering |
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Title of Presentation: |
Hydro-Dynamic Studies of
Ellipsoidal Particles in a Non-Uniform Optical Field |
Non-contact manipulation of
dielectric particles with optically-induced forces and torques is an important
goal of optical-trapping, and has tremendous value in the fields of biomedical
engineering (e.g. cell cytometry) and nanotechnology
(e.g. nanoparticle filtering). It is well known that
analytic expressions can be found for the force and torque on a spherical
particle in an arbitrary electromagnetic field (even in many textbooks on
electrostatics). However the geometry of an ellipsoidal particle in a
non-uniform field presents unique problems, such that closed expressions for
these two quantities (i.e. force and torque) have yet to be seen in the
cur-rent literature. Approximations which can be made when the field is uniform
or the particle spherical cannot be made in this case, thus the most rigorous
approach is to use the Maxwell Stress Tensor method. This method requires
knowledge of the electric field just on the boundary of the particle. The
electric field was solved using ellipsoidal harmonics, which are known solu-tions to the Laplace equation in ellipsoidal
coordinates, and a
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Gould, Troy D. |
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Department(s): |
Chemical and Biomolecular Engineering |
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Research |
George W. Roberts/Chemical
and Biomolecular Engineering Nathaniel A. Cain/Chemical
and Biomolecular Engineering |
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Title of Presentation: |
Measurement and Modeling
of Polystyrene Viscosity in Supercritical CO2 Expanded Decahydronapthalene
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Polystyrene is one of the
four most-used commercial plastics in the
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Hodges, Ryan D. Schimizzi, Ryan D. |
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Department(s): |
Electrical and Computer
Engineering |
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Research |
Michael B.
Steer/Electrical Engineering |
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Title of Presentation: |
Anechoic Chamber for
Combined Electromagnetic and Acoustic Tests |
All objects have acoustic
and electromagnetic characteristics determined by their physical attributes,
material make-up, and physical orientation relative to the source.
Traditionally these characteristics would be determined separately. However,
due to the difference in the speeds of light and sound, acoustic waves in the
range of 20Hz to 20 kHz have the same wavelength as electromagnetic waves in
the range of 17.5 MHz to 17.5 GHz respectively. This phenomenon makes the
existence of a combined acoustic and electromagnetic chamber a useful analysis
tool. The concept is that the interaction of electromagnetic and acoustic
signals can be used to characterize objects. The materials used in the
construction of the chamber as well as the physical dimensions of the chamber
all contribute to the final characteristics. To achieve the desired isolation
from outside noise sources and minimal internal reflection, several layers of
acoustic and electromagnetic radiation absorption materials were used. The
innermost layer consists of pyramidal foam tiles designed specifically for the
internal reflection and absorption of electromagnetic energy. The next layer is
a tile comprised of polypropylene beads followed by a tile of melamine foam.
The outer layer consists of heavy polymer material matting. The entire chamber
is encased by copper mesh to form a faraday cage which blocks electromagnetic
fields from entering or exiting the chamber. Preliminary tests have shown that
the chamber reduces ambient acoustic noise relative to the open but quiet lab
environment. Isolation from outside noise sources is approximately 60 dB.
|
Hon, Emily W. |
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Department(s): |
Chemical and Biomolecular Engineering |
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Research |
Bridgette Budhlall/Chemical and Biomolecular
Engineering Orlin D. Velev/Chemical and Biomolecular Engineering |
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Title of Presentation: |
Light Response of
poly-N-isopropylacrylamide Hydrogels Containing
Gold Nanoparticles |
Hydrogels are water-insoluble, crosslinked
polymer chains that are dispersed in water. They are important in many
applications, some of which include cosmetics, coatings, and foods.
Particularly important is the potential role of hydrogels
in drug delivery. Hydrogels could prove to be an
effective way to transfer antibiotics or other drugs to different locations in
the body because of their sensitivity to pH, temperature, and light. However,
in previous studies, the reaction time of the hydrogel
has been slow. In this experiment, we investigate poly-N-isopropylacrylamide-based
hydrogels with and without the addition of gold nanoparticles and their responses to light. Poly-N-isopropylacrylamide (pNIPAM)
microcapsules were prepared via photopolymerization.
The pNIPAM microcapsules respond to light and heat by
expelling water and shrinking, while swelling with water when not exposed to light
and heat. Because gold is a metal conductor, it is believed that the dispersed nanoparticles will be able to focus light and heat, causing
a faster response. The goal of this project is to develop a swelling and deswelling ratio between pNIPAM
with gold and without gold over several exposures to high and low light. Data
will provide a quantitative correlation of the effectiveness of gold nanoparticles.
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Hume, Samuel |
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Department(s): |
Electrical and Computer Engineering |
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Research |
Winser
Alexander/Electrical and Computer Engineering |
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Title of Presentation: |
A Comparison of Tools Used to Analyze System
Characteristics of Biochemical Models |
The project involved an
evaluation of two simulation packages along with the use of the Systems Biology
Markup Language (SBML) to describe and analyze biological systems. Identifying
a unified way to describe and analyze biological systems in software is a
critical component of systems biology research. It is a necessity to have
information standards if models are to be shared, evaluated, and cooperatively
developed. Otherwise, a considerable amount of time would be spent translating
biochemical reactions models from one representation to another, and valuable
information could be lost in the process. The Systems Biology Markup Language
(SBML) is a free and well-accepted XML-based language for representing and
exchanging models between simulation and analysis tools. The SBToolBox for MATLAB and the Systems Biology Workbench
(SBW) were the simulation packages used in the evaluation. The metrics used for
performing the comparative analysis of the above tools were: steady-state
analysis and stability analysis, timed simulation analysis, in-silico experiments, bifurcation analysis, parameter
estimation, and parameter sensitivity. The goal for the project was to provide
information for use to decide which tool is better suited for the analysis of a
given model.
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Hwang, Christopher J. |
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Department(s): |
Duke Clinical Research
Institute, Duke Electrical Engineering |
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Research |
Richard Becker/Duke School
of Medicine |
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Title of Presentation: |
Investigation in Coherent Anti-Stokes
Raman Scattering (CARS) Microscopy/spectroscopy as a Non-invasive Method for
Detection of Thrombotic Events |
The imaging and study of
live complex biological systems has always been of great interest. However,
problems with obtaining high-resolution images without invasive procedures has
proven difficult. Infrared radiation tuned to characteristic vibration
frequencies of chemical species has yielded great chemical selectivity, however
the longer wavelength of infrared light has limited its spatial resolution.
Fluorescent dyes or tags have improved spatial resolution, however this
requires long preparation times and risks altering chemical or molecular
behavior. Raman spectroscopy tuned to molecular vibrations has given great
chemical selectivity without staining, but requires long scan times due to the
weak Raman signal. Applications of coherent anti-Stokes Raman scattering (CARS)
microscopy has allowed for high-speed, high spatial resolution,
three-dimensional imaging without the use of fluorescent dyes or tags.
Currently CARS microscopy shows great strength in lipid detection. Research was
conducted at the Duke Clinical Research Institute and Electrical Engineering
department investigating the possibility of using CARS microscopy/spectroscopy
as a non-invasive method for detecting or monitoring coagulation or thombotic events. Research included studying current
literature and personal interviews with leaders in the CARS microscopy field
along with preliminary experiments on a lab-grade Raman spectrometer at the
DUKE ECE department. Bovine Serum Albumin along with clotting proteins
fibrinogen and thrombin were tested for detection by Raman spectroscopy.
Results from testing showed albumin concentrations as low as the millimolar range can be detected by the lab-grade
spectrometer, however no significant signal was obtained from the clotting
proteins. CARS microscopy has strengths in detecting lipids, where much of the
current research is focused. Thus, the possibility for shifting focus to lipids
specific to clotting events exists in future research.
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Jackson, Lauren C. |
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Department(s): |
Materials Science and
Engineering |
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Research |
Richard Knight/Materials Science
and Engineering, Richard Cairncross/Materials Science and Engineering, Milan Ivosevic/Resodyn
Corp. |
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Title of Presentation: |
Sliding Wear Properties of
HVOF Thermally Sprayed Nylon-11 and Nylon-11/Ceramic Composites on Steel |
The high velocity oxy-fuel
(HVOF) combustion spray process has previously been shown to be a successful
method for depositing pure polymer and polymer/ceramic composite coatings.
Polymer and polymer-ceramic composite particles have high melt viscosities and
require the high kinetic energy of HVOF in order to generate sufficient
particle flow and deformation on impact. One of the goals of reinforcing
polymer coatings with particulate ceramics is to improve their durability and
wear performance. Composite coatings were produced by ball-milling 60 μm Nylon-11 together with nominal 10 vol.% of nano and multi-scale ceramic reinforcements and HVOF
spraying these composite feedstocks onto steel
substrates to produce semi-crystalline micron and nano-scale
reinforced coatings of polymer matrix composites. The room temperature dry
sliding wear performance of pure Nylon-11, Nylon-11 reinforced with 7 nm
silica, and multi-scale Nylon-11/silica composite coatings incorporating 7 to
40 nm and 10 μm ceramic particles was determined
and compared. Coatings were sprayed onto steel substrates, and their sliding
wear performance determined using a pin-on-disk tribometer.
Coefficient of friction was recorded and wear rate determined as a function of
applied load and coating composition. Surface profilometry
and scanning electron microscopy were used to characterize and analyze the
coatings and wear scars.
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Joshi, Shaunak |
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Department(s): |
Electrical and Computer
Engineering |
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Research |
Yan Solihin/Electrical and
Computer Engineering |
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Title of Presentation: |
Analytical Cache
Performance Prediction |
Cache memory continues to play
an increasing role in the overall performance of microprocessor systems as the
difference between processor and memory speed increases. It is well known that
except for the cache size, there are several other factors that affect cache
performance such as associativity, replacement policy
etc. As a result, a high level performance model will be very helpful in
narrowing cache design space and gaining insights as to how each factor affects
cache performance. Dr. Yan Solihin
and his group have developed algorithms that provide these high level
performance models. My research involves creating a tool suite, called ACAPP,
which integrates the algorithms developed by Dr. Solihin’s
group. ACAPP is integrated into SimpleScalar, the
standard simulator used by the computer architecture and performance modeling
communities. This tool allows the algorithms to be widely disseminated through
the abovementioned communities. The input of ACAPP is the Circular Sequence
Profile which can be obtained through simulation. The output of ACAPP is the
predicted cache miss rate for different replacement policies and different associativities for a single application. The tool suite
can also predict the miss rates of two applications that share the same level
of cache (typically L2). I modified the SimpleScalar
simulator to support the functionality of generating circular sequence profiles
for inputs. I also implemented a user-interface to allow the user to easily
obtain prediction results. Moreover, I added the functionality of predicting
performance for caches with user-defined replacement policies into the tool
suite. ACAPP was introduced on February 2007 at a tutorial at the 13th
Symposium for High-Performance Computer Architecture in
|
Karra, Kiran |
|
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Department(s): |
Electrical and Computer
Engineering |
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Research |
Brian L. Hughes/Electrical
and Computer Engineering |
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Title of Presentation: |
Numerical Analysis of
Spatial Correlation in Diversity Receivers with Coupled Antennas |
The primary impairment for
wireless communications is fading - the random power fluctuations that result
from constructive and destructive interference of scattered radio waves. Many
techniques can be used to overcome fading, which include diversity transmission
and reception, space-time codes, and MIMO. This presentation will focus on
diversity reception, which entails using multiple antennas to receive signals.
Diversity receivers work on the principle that if the antennas are placed far
enough apart, one of them may receive a stronger signal than the other.
However, in mobile communications equipment such as cell phone, space is very
limited. As a consequence, the signals that are captured by the antennas
electromagnetically couple. This means that the signals are correlated, which
leads to reduced performance. Under certain assumptions, in a narrowband fading
channel, the fading may be modeled statistically as the correlation of
electromagnetic waves in free space at two separate points, which is given by a
zeroth order Bessel function. This holds true for the
correlation of open circuit voltages between two uncoupled antennas. However,
if two antennas are coupled, then current in one antenna can induce current in
the other antenna. The mutual coupling between antennas may be solved
analytically for the case of two infinitesimally thin dipoles. We wish to
explore the effect of mutual coupling on diversity performance for more
realistic cases. To do so, we use a numerical electromagnetic software package
to determine the open circuit correlation between an array of dipole antennas
of finite thickness. To relate these numerical results to the established
theory for uncoupled antennas, we fit the data to a series of Bessel functions
of increasing order. Our NEC simulations have shown that adding Bessel
functions of higher orders proportionally will allow us to predict signal
correlation of coupled antennas.
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Katz, Donald |
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Department(s): |
Civil Engineering |
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Research |
John R. Stone/Civil
Engineering |
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Title of Presentation: |
Development of Typical
Truck Trip Profiles for Rural and Urban NC |
Efficient freight
transportation is critical to a healthy economy for North Carolina (NC). Trucking,
in particular, provides a vital and reliable mode of transporting regional and
intra-regional goods movements in NC. On
the other hand, the fast growth in truck flows has significantly contributed to
traffic congestion, vehicle emissions, and pavement and bridge damage. Since
the effect of truck loads on pavement and bridge performance increases
exponentially with truck weight, it is important to quantify the cost of heavy
truck and overweight trucks to the NC roads system as a whole. Accurate information
on truck weight distributions can assist DOT transportation planners and
engineers to estimate the cost of early failure of the NC road system due to
heavy and overweight trucks, and accordingly determine equitable fee structures
and weight law enforcement. Using overweight truck data from NCDOT, a profile
of Interstate 40 was created. Its distribution of truck weights and frequency
for each mile marker shows where the most critical portions of the highway are.
Although this only reflects one week of data, the profle
will help motivate NCDOT to provide additional data in the future. With a years
worth of data, a complete profile can then be created. This will show where the
focus areas are on this one particular highway. The process of creating this
profile shows problems which will need attention when streamlining the profile
creation process. Roads which interset the highway
multiple times, roads with multiple names, and decision rules to work by were
all encountered. It is necessary to provide thorough instructions if this were
process were to be continued manually, or if it were programmed for a computer
to work through.
|
King, Matthew R. Disseler, Steven M. |
|
|
Department(s): |
Materials Science and
Engineering |
|
Research |
Jerry Cuomo/Materials
Science and Engineering |
|
Title of Presentation: |
Atmospheric
Plasma-Enhanced Soft Hydrolysis of Southern Pine |
The production of
fermentable sugars from southern pine using atmospheric plasma (AP) was studied.
AP processing in the dielectric barrier discharge (DBD) configuration was
coupled with acid hydrolysis in an effort to determine how AP can impact a
standard conversion technique. The effects of plasma chemistry (5%O2/95%He and
5%Air/95%O2), treatment time (10 seconds and 10 minutes), and electrode
polarity (top-driven and bottom-driven) on the production of sugars were
evaluated using HPLC, FTIR, and SEM. It was found that AP-treated samples
produced over 50% more total sugar than untreated samples. It was also found
that the AP process degrades the lignin component of the substrate, a
significant inhibitor to sugar production. Treatment time was the most
significant factor in sugar production, although plasma chemistry had an effect
on the surface chemistry of the substrate. With such an increase in sugar
production for treated samples, this process has the potential to significantly
impact the efficiency and cost-effectiveness of the biomass conversion process.
|
Kirkpatrick, Casey J. |
|
|
Department(s): |
Electrical and Computer
Engineering |
|
Research |
Mehmet C. Ozturk/Electrical and
Computer Engineering |
|
Title of Presentation: |
Hall Effect System for
Semiconductor Measurements |
When a DC current flows
through a semiconductor in the presence of an orthogonal magnetic field, a
voltage can be measured perpendicular to the direction of the applied current.
This phenomenon is referred to as the Hall Effect and it is commonly used to measure
the mobility and active carrier concentration in thin crystalline layers grown
on semiconductor wafers. The project started in spring 2007. The initial work
involved acquiring the components to set up the Hall Effect measurement system,
which included a light-tight sample box with internal probes, a DC
electromagnet, a gauss meter, and an electronic controller, which serves as a
precision current source and voltmeter. The sample holder was designed as part
of this work and it was manufactured by the NCSU precision machine shop. After
the system set-up was complete, the preliminary work focused on optimizing the
measurement parameters for reliable measurements. The effects of the
measurement current and the magnetic field were investigated. It was found that
that the measurement current had an optimum range to achieve a high
signal-to-noise ratio and avoid sample heating. It was found that once
sufficiently high, the magnetic field had no observable effect on the measured
properties. The long-term objective of this work is to carry out fundamental
studies on heavily boron doped, p-type Si-Ge alloys
grown on n-type Si wafers by ultrahigh vacuum rapid thermal chemical vapor
deposition. Preliminary results indicated that the system is capable of
producing reliable measurements. The current phase of this work is focused on
the impact of strain on the mobility and active carrier concentration in
heavily boron doped SiGe layers. The amount of strain
in the epitaxial layer is adjusted by growing the
films at different thicknesses to achieve films that are strained and fully
relaxed.
|
Lawler Jr., Kristopher F. |
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|
Department(s): |
Electrical Engineering |
|
Research |
John F. Muth/Electrical Engineering |
|
Title of Presentation: |
Design of a MEMs Torsional Mirrors |
The mask design of an array
of MEMs Torsional Mirrors
is presented. The design allows the mirrors to be individually electrically
addressed. By incorporating these mirrors as part of a Fabry
Perot cavity, the frequency of mechanical vibration of the mirrors can be
monitored and displacements measured with very high precision. One application
of these mirrors is chemical and biological sensing.
|
Marshall, Kristina Felker, Angela Rebovich, Mary |
|
|
Department(s): |
Materials Science and
Engineering |
|
Research |
Rich Spontak/Materials
Science and Engineering |
|
Title of Presentation: |
Development of Bonding and
Matching Layers for Acousto-Optic Device Applications |
The purpose of this senior
design project was to identify and design an acoustic impedance matching layer
and a bonding layer for an acousto-optic (AO) device to expand Northrop Grumman’s
knowledge base concerning these layers and aid in the development of a more
efficient AO device operational in the infrared light range. The team studied
the chemical compositions and bond strengths of three Norland
Optical Adhesives (NOA):61, 68 and 81. Analysis through Fourier Transform
Infrared (FTIR) spectroscopy of these bonding materials illustrated the various
compositions and chemical bonds present. Qualitative comparison of the
adhesives through peel tests provided information about relative bond
strengths. The team explored the possibility of combining the matching and
bonding layers by incorporating typical matching layer nanoparticles
into the adhesives, and these combinations were analyzed via measurement of the
dielectric loss constant and peel testing.
|
Morrow, Joseph M. |
|
|
Department(s): |
Mechanical and Aerospace
Engineering |
|
Research |
Ashok Gopalarathnam/Mechanical
and Aerospace Engineering Jeffery Jepson/Mechanical and
Aerospace Engineering |
|
Title of Presentation: |
Increasing Fuel Economy in
Aircraft by Decreasing Drag |
In order to study the drag
properties of airfoils, significant attention has been directed towards two-dimensional
computational studies and experimental testing. To simulate two-dimensional
flow, special focus has been given to wind tunnel models spanning the entire
test section. By extending the wingtips until flush against the sidewalls of
the wind tunnel, finite wing effects on flow variation can be greatly reduced,
allowing for the two-dimensional cross-section to be studied. Two-dimensional
cross-sectional studies are believed to uncover clues leading to decreasing
drag and increasing fuel consumption. This poster presents a possible method
for correcting inaccurate pressure data due to natural flow variation and
outlines a method for drag coefficient calculation of two-dimensional airfoils
using wake pressure scans of a multi-flapped, multi-sectioned, auto-adaptive
2-D airfoil. Initial results indicate that integrating wake scans can provide
acceptable figures for accurate drag coefficient calculation, but further
testing must be carried out before this can be confirmed. The multi-flapped
airfoil used in these experiments features automatic adaptive capabilities. The
algorithm used in this process ensures that the airfoil maintains low drag
while providing necessary lift. This poster proposes a method to calculate the
drag properties of the adaptive airfoil and confirm its ability to minimize
drag under low-speed conditions. Upon verification of drag reduction, the
implementation of the adaptive airfoil may increase fuel economy by decreasing
drag.
|
Mulholland, Gregory J. |
|
|
Department(s): |
Electrical and Computer
Engineering |
|
Research |
Veena Misra/Electrical and
Computer Engineering |
|
Title of Presentation: |
Comparative Investigation
of Redox-active Molecular Band Interactions with Semiconductor
Substrates |
Molecular electronics are a
hotly debated emerging field with great potential for advancing bottom-up nanoscience approaches to building gigascale-density
computing devices. Specific synthetic organic molecules have shown requisite
electrical properties for charge and spin devices; but the energy state
interactions are not well understood. The investigation of the band-chemical
potential interactions in molecular layers is important to understanding
detailed mechanisms for metal contacts with these molecules. In recent work, it
has been shown that the substrate type matters greatly to the performance of
the device. On p-type silicon, molecular capacitors behave as expected under
dark standard laboratory conditions. Standard capacitive charging current is
seen, with a peak in current at the specific oxidation-reduction (redox) potentials of the molecules. Only under the
application of light do n-type devices begin to show the characteristics of
p-type devices. This suggests that by optical generation of holes in the
valence band in n-type Si, the conditions for charge transfer are improved. The
chemical potential of the molecular layer aligns itself with the Fermi level of
the semiconductor, but actually exchanges electrons with the valence band. The
Highest Occupied Molecular Orbital of the organic layer is comparable to the
valence band of the semiconductor, while the Lowest Unoccupied Molecular
Orbital is comparable to the conduction band. When a bias is applied, an
electron tunnels from the organic layer to the semiconductor valence band. To
accurately gauge the correct band structure of these devices, substrates of
varying band offsets must be chosen. Fc-BzOH
molecules were attached to n-type Silicon (Si) and Germanium (Ge) substrates and tested for light dependence, scan rate
dependence, and oxidation-reduction voltages using Cyclic Voltammetry.
Preliminary Ge samples show redox
at higher voltages than that of n-type silicon, corresponding to the band
offset of the Ge valence band relative to Si.
|
Munilla, Samuel R. Jhala, Arnay Rawls, Curtis Macik, Amanda |
|
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Department(s): |
Computer Science |
|
Research |
R. Michael Young/Computer
Science |
|
Title of Presentation: |
Longboard, Toward an Intelligent Storyboarding Tool |
Longboard is a collection of tools used for generating movies
on game engines. Users can author scripts and visualize them on the Unreal
Tournament game engine. Longboard provides an
intuitive Tablet PC interface for authoring scenarios and sketching storyboard
frames that are communicated to a game engine controller for execution. Longboard communicates with an external planner – Darshak – for planning intermediate unspecified actions
from the user generated scenario. In the Longboard
system, users specify movie directives through a storyboarding interface. The
Tablet PC provides a natural interface for drawing storyboard frames. Users have
the freedom to sketch characters and objects through the pen using the built-in
drawing functionality. This avoids having the user learn manipulation of 3D
models in the interface. Pen input provides a shallow learning curve for users,
interpreting both stick-figures and professionally drawn characters. The stroke
recognition system also allows users to annotate the storyboard frames with
text and stage directions in addition to characters and objects in the 3D
world. The story and camera planners allow a user to create a partial
specification for an action sequence of the movie and then add remaining
actions to automatically complete full scenes. Users create a script and a set
of storyboards in the Longboard user interface. The
advantage of having a planner in the system is that users may not want to
specify every action or camera placement in their film. Users can either accept
or reject the suggested shots by the planner by specifically adding constraints
on certain frames or by adding new frames to the storyboard. The user can then
send the completed plan to the Renderer. The Renderer takes advantage of game engine technology to
create a video of a rich 3D environment. The Longboard
Renderer uses the Unreal Tournament engine to create
a virtual world that has a library of sets for setting up the film environment.
The Renderer's Execution Manager manipulates the
actors and camera to follow the action sequence specified by the Longboard interface.
|
Nobles, Larrisha
R. |
|
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Department(s): |
Chemical and Biomolecular Engineering |
|
Research |
Richard J. Spontak/Chemical and Biomolecular
Engineering, Material Science and Engineering |
|
Title of Presentation: |
Surface Modification of Electrospun Polymer Blends |
Currently, there are few
single-step methods designed to functionalize the surface of polymer nanofibers. Therefore, this project explores the
feasibility of achieving single-step surface modification via electrospinning. Through this unique process, fibers
ranging from tens of nanometers to tens of microns in diameter can be produced
by using an electric field to overcome the surface tension of a polymer
solution or melt. The ultrathin fibers produced by electrospinning are suited for a diverse range of applications
due to their large surface area to volume ratio. The objective of the present
research is to fabricate surface-biofunctionalized nanofibers composed of several different polymers (e.g., polymethyl methacrylate, PMMA)
via addition of novel bio-organic co-oligopeptides
composed of SEE and RGD domains. The effects of added co-oligopeptide
on fiber morphology and surface chemistry are deduced by scanning electron
microscopy and x-ray photoelectron spectroscopy, respectively. Current
objectives of this research project include studying the elctrospinning
of PMMA and PMMA/PEO blends for their use as the fiber-forming polymer. In
addition to surface modification, the effect of selective PEO extraction of
PMMA/PEO blends on fiber morphology has been investigated.
|
Poovey, Jason |
|
|
Department(s): |
Electrical and Computer
Engineering |
|
Research |
Thomas M. Conte/Electrical
and Computer Engineering |
|
Title of Presentation: |
Benchmark Characterization
of the EEMBC Benchmarks |
Benchmarking has long been
used to measure the performance of desktop systems, servers, and high end
computers. In these situations, the characteristic architecture and
applications that are run are well known in advance. In the market of embedded
processors; however, the workloads vary greatly. Because of this, it is very
difficult to create a suite of benchmarks that accurately depicts any given
user’s workload. Instead, the best option is to create a suite of lightweight benchmarks
with varying workloads. One such benchmark suite, and the test suite of this
research, is the EEMBC Suite of Benchmarks which is an industrial consortium
that creates these industry-standard benchmarks for embedded microprocessors.
This research aims to fully characterize each of the EEMBC benchmarks, examine
the benchmark’s effectiveness and give developer’s data with which to compare
workloads to the characterization. The purpose of characterization is to give a
common set of metrics for all benchmarks and classify them based on their
performance in each metric. Some example metrics are IPC, Cache Size, and
Branch Misprediction. Bringing the data of each
metric together in a single graph reveals a”shape”
for each benchmark. From this shape we are able to see characteristics such as
which benchmark is “memory active” or hard to predict. This data is analyzed to
determine the overall effectiveness of the EEMBC benchmarks, and it allows
users to match their workloads to a specific EEMBC benchmark, thus allowing
them to build a design that is optimal for that characterization. The final
goal is two-fold. Data is being collected to fully characterize the benchmarks
in all of the EEMBC suites, and is almost complete. We are beginning to
transition into the next phase which is to automate the tools used for
characterization so that users can characterize their own code.
|
Ravichander, Aparna Bowman,
Michelle |
|
|
Department(s): |
Chemical & Biomolecular Engineering Materials Science &
Engineering Textiles & Polymer
Science |
|
Research |
Richard J. Spontak/Chemical Engineering, Materials Science Tushar Ghosh/Textiles and
Polymer Science |
|
Title of Presentation: |
Electrical and Mechanical Properties
of Carbon Nanofiber and Carbon Nanotube
Block Copolymer Composites |
Carbon nanoparticles
have been used as excellent avenues to convert insulating polymeric materials
to electronically conducting materials. When a polymer containing carbon nanoparticles is exposed to a particular strain, the nanoparticles shift and touch one another, forming a
connecting channel for an electric current to pass through. This percolation
threshold allows for a material to behave as a conductor, as a deformation is
applied, and an insulator, when the material is relaxed. In this work, 0.5 wt%
carbon nanofibers (CNF) and 0.5 wt% carbon nanotubes (CNT) have been added to a
polystyrene-b-(ethylene-co-propylene)-b-styrene (SEPS) triblock
copolymer block copolymer. The composites were both solvent cast, yielding
isotropic materials, and extruded, resulting in anisotropic nanocomposities.
Since fibers have a much higher aspect ratio than spherical particles, a lower
concentration of nanoadditives is required to reach the
percolation threshold of these SEPS/carbon fiber nanocomposites.
The isotropic and anisotropics samples yield markedly
different resistivity data. Also examined were
thermoplastic elastomer gels consisting of 10 wt%
SEPS and 90% mineral oil. Since these materials are highly elastic, they
require more strain to reach the percolation threshold, and given a broader
curve for the log R (resistivity) vs. l/lo (deformation) data. According to the data, the
percolation threshold was not achieved implying that the SEPS/oil materials
require a higher concentration of CNFs and CNTs to reach the percolation threshold.
|
Ross, Matthew E. Goodwin, William Lazar, Kevin |
|
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Department(s): |
Materials Science and
Engineering |
|
Research |
Michael Rigsbee/Materials Science and Engineering |
|
Title of Presentation: |
Failure Analysis of Crane
Wire Rope |
The research has focused on
determining the cause for premature fracture in operating crane cable wire ropes
at Nucor Steel - Hertford. Wire rope is used extensively in crane and elevator
operation, as well as, in suspension bridges, roller coasters, and moorings. A
typical wire rope consists of many strands of steel wires. These strands are
then woven together in a variety of ways to create a high strength wire rope.
Most wires are assembled from high-carbon, plain carbon steel which are heavily
drawn with extremely cold-worked microstructures. Individual wires within the
cables are subjected to varying stresses including tension, compression,
torsion, and shear. This is due to wires sliding and bending over one another
which ultimately results in a system that can attain very high strengths while
retaining flexibility. Failure analysis was performed to determine the fracture
mechanism and a proposal was formulated to optimize operation parameters and on
the specific type of wire rope used. It was determined that abrasions to the
outer wires combined with the torsional nature of the
stresses within the wire rope caused longitudinal cracking, which ultimately
resulted in overloading failure of the wire rope. To prolong wire rope life, it
has been recommended that additional maintenance procedures be introduced such
as regular inspection of all machinery in contact with the rope as well as
regular lubrication of the wire rope.
|
Royce, Liam A. |
|
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Department(s): |
Wood and Paper Science |
|
Research |
Dimitris Argyropoulos/Wood and
Paper Science |
|
Title of Presentation: |
Toward Wood-Polyethylene
Composites |
There has been an increasing
trend in research to design materials that are both recyclable and
biodegradable and able to meet the property requirements. Synthetic-biopolymer
blending can add recyclability and biodegradability
to a fiber. The possibility of blending modified wood with polyethylene into a
fiber was investigated. Southern Pine sawdust was derivatized
with palmitoyl chloride in
1-butyl-3-methylimidazolium chloride (BMIMCl). For
the first time, a homogeneous reaction became possible. The palmitylated
wood was blended with high-density polyethylene in a twin-screw extruder. A
take-up system was used to spin the blended material into a homogeneously mixed
fiber. This blended material was examined for its thermal properties.
Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed that the product
still needed to be purified. This work will continue to have a fundamental
understanding of homogeneous derivitization of wood
and blending with plastic to produce an advanced wood composite.
|
Seyam, Mohamed A. |
|
|
Department(s): |
Chemical and Biomolecular Engineering |
|
Research |
Richard Spontak/Chemical and Biomolecular
Engineering, Materials Science and Engineering |
|
Title of Presentation: |
Cross-Linked Polymer Nanocomposites for H2 Gas Separation from CO2
|
Gas separation is an
important process in the chemical industry, particularly in the separation of
the products resulting from the water-gas shift reaction during steam
reformation of hydrocarbons. In this process, hydrogen (H2) must be
separated from a mixed gas stream containing primarily carbon dioxide (CO2),
but also potential trace amounts of water (H2O) and carbon monoxide
(CO). Hydrogen gas is utilized in many different ways. For instance, in the
growing demand for alternative energy sources, hydrogen fuel cells have emerged
as an important consideration. It has become industrially important to reduce energy
and economic demands of current gas separation processes and polymer membranes
provide an attractive opportunity to achieve this goal. In this study, we have
examined the gas separation properties of a cross-linked polyimide containing
as-grown palladium (Pd) nanoparticles. Implementation
of Pd nanoparticles into these polymer membranes
decreases the free volume of the membrane as well as improves the affinity for
H2 over other gas species. Additionally, chemical cross-linking of
the membranes further reduces free volume and increases chain rigidity, aiding
in the prevention of CO2 plasticization and precluding relatively
larger gas molecules to penetrate.
|
Sheeran, Paul S. |
|
|
Department(s): |
Electrical and Computer Engineering |
|
Research |
Maysam Ghovanloo/Electrical and
Computer Engineering |
|
Title of Presentation: |
DC-DC Converters for Ultra
Low-Power Switched-Capacitor Based Implantable Wireless Microstimulating
Systems |
Wireless microstimulators
are one of the emerging technologies that could be used to treat many
biological dysfunctions. Because the battery size takes up a large percentage
of the overall space (>50%), reducing its size through efficient power
management is crucial in reducing the overall size. This project uses a
switched-capacitor stimulation system (SCS) to provide the stimulus through a
group of capacitors that are charged regularly by a rechargeable battery using
a DC-DC converter. The goal of this research is to identify the favorable
characteristics of each potential topology and compare them to determine the
best-suited to implement in the SCS system. By finding the most appropriate
topology, the overall SCS system will be more effective and more efficient as
well as small in its overall size. To approach this I conducted a survey of the
literature available on converter topologies and their advantages before
looking for the best-suited commercially available samples. I designed the
necessary circuits to test each sample and developed a PCB test harness. I had
the harness manufactured and constructed the circuits to gather test data of
the different chips and how they performed with respect to each other in regard
to several parameters. I used this information to determine which DC-DC
topology was best suited for the SCS system. My findings show that different
topologies yield inherent advantages–some require lower input current while
some require less capacitor charge time. Although results have not been finalized
yet I expect, based on the preliminary results, that the “synchronous boost
converters” will yield advantages in key areas. They seemed to have the best
characteristics of input voltage–being able to produce a 5V output at a 0.5V
input with the addition of excellent regulation of the signal even as the input
voltage exceeded the output voltage.
|
Stewart, S. Michael |
|
|
Department(s): |
Chemical and Biomolecular Engineering |
|
Research |
Gregory Parsons/Chemical
and Biomolecular Engineering G. Kevin Hyde/Textiles |
|
Title of Presentation: |
Atomic Layer Deposition of
Titanium Nitride on Cotton Fabric |
The deposition of titanium nitride onto woven cotton fabric
was investigating using an atomic layer deposition method. Untreated cotton
samples were dosed using tetrakis(dimethylamino)titanium
(TDMAT) and ammonia via an atomic layer deposition (ALD) process in order to
attain a controllable, conformal coating on the surface. The aim of these
studies was to both verify a practical means of applying a metal thin film to
cotton for advanced application, as well as lay the ground work for additional
metal deposition, such as silver and copper on cotton, for antimicrobial
applications. Deposition was confirmed using x-ray photoelectron spectroscopy
(XPS) and Auger electron spectroscopy (AES) on cotton and silicon samples,
respectively. Physical changes in the cotton after treatment such as color
change and hydrophobicity were also investigated. Hydrophobicity was monitored by static water contact angle
measurements, and results showed that the surface of the cotton was more
hydrophobic than similarly prepared flat surfaces. Work is continuing on this
and other metal deposition processes on cotton and other complex surface
structures for more permanent antimicrobial application.
|
Stille, John C. |
|
|
Department(s): |
Computer Science |
|
Research |
Tao Xie/Computer
Science |
|
Title of Presentation: |
Correlating Outputs of
Static Code Analysis Tools for Security |
Static analysis of software code has provided a
cost-effective way of managing bugs found throughout the development cycle.
Security analysis of software code is a fairly new topic in academia and has
been researched through tools, such as LAPSE and FindBugs.
The results of different analysis tools on the same code base have been shown
to provide different, yet useful, results. When running these tools and having
to analyze all of the resulting data, tool users need to overcome a set of
encountered problems: in the large amounts of reported data, bugs can seem
hidden from developers and bug duplicates must be removed. In our research, we
propose a tool that will include modules for parsing output data, to correlate
the security vulnerabilities into a standardized XML syntax. Each module will
transform data reported by a given analysis tool. The tool will in the end
remove duplicates, reduce the number of bugs to help developers prioritize
them, and allow multiple tools to provide different results using their
heuristics. Through the use of this tool, we expect to provide an easy-to-use
API for future static analyzers to plug into our system and exploit the
proposed XML schema. Once a standardized output format is created, the time
required for data processing will be greatly reduced, saving time, energy, and
money for analyzing large projects.
|
Thompson, John F. Gozen, Arif O. |
|
|
Department(s): |
Chemical and Biomolecular Engineering |
|
Research |
Jan Genzer/Chemical
and Biomolecular Engineering Richard J. Spontak/Chemical and Biomolecular
Engineering, Materials Science and Engineering |
|
Title of Presentation: |
Effect of Added Block
Copolymers on Polymer Thin-film Dewetting Rate and
Mechanism |
The stability of thin liquid films of polymers, such
as polystyrene (PS) and poly(methyl methacrylate) (PMMA) is important in numerous applications
such as printing because adjacent layers of polymers must remain intact and not
rupture. Dewetting is a general phenomenon and occurs
when a thin liquid film becomes unstable and breaks up as it tries to reduce contact
with a surface. Previous studies have shown that PS thin films dewet from PMMA at elevated temperatures. In the system
studied here, PS dewets from PMMA and forms holes and
then sessile droplets when at temperatures above the upper glass transition
temperature. Recent work indicates that the incorporation of a PS-b-PMMA diblock copolymer into the PS can reduce the dewetting rate and change the dewetting
mechanism from nucleation and growth to spinodal-like
dewetting. The present study addresses the effectiveness
of PS-b-PMMA diblock copolymers varying in molecular
weight and concentration in PS films varying in thickness, as well as the
associated mechanism and rate by which the modified films dewet.
|
Tucker, Jarrod A. |
|
|
Department(s): |
Paper Science Engineering |
|
Research |
Lucian A. Lucia/Paper
Science Engineering |
|
Title of Presentation: |
Investigation of Acidic
Peroxide Pretreatment Upon Hardwood Kraft Pulp Bleaching Costs – A Statistical Designed Investigation of Operating
Parameters |
As the profit margin of many grades of paper have
narrowed, it has become necessary to optimize and reduce costs throughout the pulpmill, bleach plant, and papermill
operations. Chlorine dioxide is the most expensive and most prevalent bleaching
chemical used in traditional bleaching sequences and, for this reason there is
a need to reduce its usage. Several marginal pretreatment methods have been
reported in the literature. Enzyme pretreatment and alkaline peroxide
pretreatment have been extensively studied. Enzyme pretreatment has been used
to reduce operating costs and increase production, while maintaining current
pulp yields and BOD production [1]. One literature source from a British
Columbian pulp mill has suggested that improved performance may be obtained by
using acidic peroxide. Very little technical work has been done with this
pretreatment method. The current study will examine the cost effectiveness,
performance, and operational characteristics of acidic peroxide pretreatment of
brownstock pulp as a method to reduce the overall
bleaching cost. Limited literature data suggests that the use of Fenton
Chemistry (acidic peroxide in the presence of ferric iron) as a brownstock pretreatment method will substantially reduce
the overall bleaching cost associated with a kraft
pulp bleach plant [2]. Initial screening investigations, conducted during the
Fall 2006 semester in a mandatory PSE class (WPS 415), suggested that
appropriate levels of acidic peroxide application are financially attractive
while other levels of acidic peroxide application are cost prohibitive. The use
of a statistical designed experimental plan will be employed to examine the
response of treatment pH and peroxide charge on total bleaching costs.
- Biological Sciences abstracts
Applied Sciences (Crop, Poultry, Animal, and Horticultural Sciences)
Ecology, Environmental, Conservation, Botanical
Molecular, Biochemical, Genetics, Cell Biology
Zoology, Physiology, Behavior, Neurobiology
- Design abstracts
- Humanities, Social Sciences, Psychology abstracts
- Physical and Mathematical Sciences abstracts
[ 2007 Undergraduate Research Symposium
Main Page ]
Last modified February 2007 by Sharon
E. Hunt, WordHunting