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Congratulations to Herff students who placed and participated in the 2022 Works in
Progress Symposium (WIPS). Students throughout the campus community compete in seven
categories to win first or second place in each: Engineering; Physical and Applied
Sciences, Math and Computer Sciences, Social and Behavioral Sciences, Education, Health
and Life Sciences, and Liberal and Fine Arts.
WIPS provides undergraduates with an opportunity to share their research with peers
as well as professors. Undergraduates who have conducted original research, scholarly,
or creative projects under the guidance of a faculty mentor are invited to submit
an application to WIPS. This symposium also welcomes presentations by students who
are just beginning projects, and affords students the opportunity to present the background,
rationale, plans and preliminary results from a project that is ongoing, rather than
complete.
Herff 1st Place Winners
Krista Dyer, Mechanical Engineering
Fatigue of Additively Manufactured Ti-6Al4V Cellular Structures under Uniaxial, Torsional,
and Multiaxial Stresses
Category: Engineering
Mentor: Dr. Reza Molaei, Mechanical Engineering
Additive manufacturing (AM) is a rising, largely applicable manufacturing procedure.
The ability to build complex geometry components is one of the many advantages of
AM. Included in these complex geometries are metallic cellular structures. These structures
have a variety of applications in fields such as biomedical, automotive, and aerospace
engineering. To ensure the full range of applications can be utilized, it is vital
to understand the fatigue behaviors of the porous structures. Fatigue is the result
of cyclic loading and may cause components to fail at much lower stresses than their
ultimate or yield strengths. There is a major gap in the information with regards
to loadings outside of compression-compression. The purpose of this study is to model
and predict the fatigue properties and behavior of Ti-6Al-4V cellular structures,
under uniaxial, torsional, and multiaxial loadings. This research is divided into
three stages: manufacturing, testing, and modeling. For this project, all components
are built using the Laser Powder Bed Fusion AM technique. Analysis of the test results
will lead to a single numerical model to predict the fatigue behavior for different
porosities under any combination of loading.
Sophie Wood, Mechanical Engineering
Sub-grid Scale Characteristics of Godunovbased Schemes for Cavitating Two-Phase Flows
Category: Physical and Applied Sciences
Mentor: Dr. Daniel Foti, Mechanical Engineering
Numerical accuracy of large-eddy simulations for cavitating flows decreases near discontinuities
such as shock waves generated by vapor-bubble collapse, vapor-liquid phase boundaries,
and complexities of solid boundaries. The errors can often be attributed to explicit
sub-grid scale models. An alternative methodology, implicit large-eddy simulation,
leverages the numerical discretization error of monotone, sharp-interface capturing
schemes to mimic the physical dissipation rate. The characteristics of the numerical
dissipation rate and implicit sub-grid scale are detailed for a class of Godunov-based
schemes for cavitating flows discretized in generalized curvilinear coordinates. Because
the variable reconstruction is performed locally, the scheme can capture both discontinuities
and low Mach number features. Leading terms of modified equation analysis confirm
the dissipation behaviors. A series of cases are undertaken including two-phase shock
tube, homogeneous isotropic turbulence, and cavitating flow over a cylinder, which
employs a sharp-interface immersed boundary method for compressible flow. The turbulence
spectra, statistics and void fraction profiles show good agreement with direct numerical
simulation.
Herff 2nd Place Winners
Jada Sandridge, Biomedical Engineering
Touch-spinning Polydioxanone and Polycaprolactone to Develop Small Diameter Vascular
Grafts
Category: Engineering
Mentor: Dr. Gary Bowlin, Biomedical Engineering
Cardiovascular diseases are common conditions that affect the heart or blood vessels.
These diseases can affect blood flow due to blood clots or narrowing of the blood
vessels in a process known as atherosclerosis. Due to its prevalence, it is important
to develop a vascular graft that can be used to replace or bypass a damaged vessel
when there is a limited supply of autologous vessels. A current treatment is a synthetic
vascular graft made from either ePTFE® or Dacron®. While these grafts have had high
success in diameters larger than 6 mm, there has been low success in diameters smaller
than 6 mm due to rapid occlusion and thrombosis. To develop resorbable vascular grafts,
spinning techniques, such as touch spinning, can be used. Touch spinning is a process
that mechanically draws out fibers. Using this technique, the aim of this study will
be to develop resorbable, small diameter vascular grafts that can be used as an alternative
to autologous vessels in surgical procedures. Both polydioxanone (PDO) and polycaprolactone
(PCL) will be dissolved in HFP separately. PDO will be used due to its high flexibility,
mechanical strength, and degradation rate. PCL will be used due to high flexibility,
elasticity, and degradation rate. The two types of grafts will be examined under a
scanning electron microscope to further examine and validate the pattern of the fibers.
Mechanical characterization will also be performed to determine their potential use
as a vascular graft.
Riley Morris, Electrical Engineering
Introduction to Ciphers in Cryptography
Category: Math and Computer Sciences
Mentor: Dr. James McGinnis, Engineering Technology
Security is a major deal in today’s culture due to the accessibility of information
over the internet. The internet provides a vast space to exchange private information
such as social security numbers, credit cards, and health care information. This information
is typically protected using encryption. Cryptography was created out of the need
to conceal information and is simply the means by which one is able to encrypt information
through codes or ciphers and then decrypt these encrypted messages utilizing keys.
Cryptography takes unencrypted data also known as plaintext and applies an encryption
method that transforms the data into ciphertext. One can then apply a key to this
ciphertext in order to decrypt the data. A huge aspect of this process is authentication.
One needs to ensure that they are receiving the message from the right person and
that the right person is able to interpret the message. One huge way cryptography
can authenticate is utilizing a key system. Just like how one needs to have a key
to enter a locked house, one must have a key to decrypt a “locked” message. In cryptography,
there are public and private key algorithms both helping decrypt and encrypt secret
messages.
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