Lehigh Engineering's annual Undergraduate Research Symposium, held each spring, showcases the intense academic capabilities of today’s rising Lehigh Engineers, and highlights the resources and opportunities Lehigh provides to undergraduates.
Each year, the event helps student-competitors, nominated by their departments, learn how to express the significance and complexity of their work and answer questions posed by faculty, students, and visitors.
The top finishers, judged by a panel of academic and industry researchers, win travel stipends to attend professional conferences yet another opportunity to promote their work and practice the art of communication.
2016 Second Place
Dissimilar Metal Welds (DMWs) are critical for design, development, and manufacturing of Very High Temperature Reactors (VHTR). When the DMW is in service, experience has demonstrated that premature failures of DMWs can be caused by carbon diffusion across the weld interface from the ferritic to austenitic material, driven by the large concentration gradient. This creates creep voids near the weld interface that are the leading cause to premature failure in service. A proposed solution is a joint whose composition changes gradually from ferrous to austenitic steel to mitigate carbon diffusion during service due to the smaller concentration gradient. This research proposes that a graded transition joint (GTJ) will exhibit minimal changes in hardness when compared to the DMW, suggesting carbon diffusion will be limited. DICTRA simulations were performed to determine a suitable grade length for the GTJ. A 20 mm grade length was calculated to have the least amount of carbon diffusion after aging at 465˚C for 20 years. Samples of DMWs and GTJs were fabricated, prepared, and hardness tested in the as welded and aged conditions. The DMWs exhibited large changes in hardness over short distances due to carbon diffusion, while the GTJ does not exhibit drastic changes in hardness values after aging. Longer aging times affect the hardness in DMWs but not GTJs, with the GTJs exhibiting no local softening near the fusion line. Future work will include hardness tests after longer aging times with finer spaced traces to continue investigation of carbon diffusion.
2016 Third Place
There is an increasing number of human diseases that originate from animal reservoirs, zoonoses, such as the Zika and Ebola virus. In the case of Ebola, there has been significant progress during the last decade to support the hypothesis that African fruit bats are the natural reservoir of the Ebola virus. The recent Ebola epidemic occurred in Guinea (West Africa), where no Ebola virus had been recorded before. The strain of the virus has been identified as Zaire (the deadliest one) that had previously only been found in central Africa, thousands of miles away. Understanding the mechanisms for bat migration of great distances can reveal information about how Ebola spreads. Our hypothesis is that environmental pressure, i.e. the decrease of resources such as food and shelter due to seasonal alterations, challenges the population’s survival and is the main driving force for bats’ migration. In order to test this hypothesis, we propose a mathematical model to study the spatiotemporal dynamics of bat populations. The model splits bats’ population into susceptible, infected and recovered subpopulations and takes into account the most fundamental processes that drive the disease dynamics, including how those depend on the environmental conditions and the seasonal variations. Analytical calculations and numerical simulations produce results of stable oscillations for each subpopulation due to environmental pressures. These results provide information on how Ebola outbreaks can occur in the African fruit bat population.
Patrick Barry and Xu Yan
2016 Honorable Mention
Since its discovery in the late 19th century, synthetic rubber has become a popular replacement for natural rubber. Currently, the world produces and consumes more synthetic rubber than natural rubber. In the first half of 2015, the United States alone produced and consumed 1.5 million tons of synthetic rubber, more than 20% of all synthetic rubber produced in the world at the time. To manufacture synthetic rubber, 1,3butadiene must be produced and polymerized. Presently, steam cracking of petroleum naphtha remains the most popular and costefficient manufacturing process. Alternatives are actively being researched due to the unsustainability of the oil industry. This research focuses on the conversion of ethanol to butadiene. ZrOSiO2 catalysts, produced by wetness impregnation, are studied with TPSR, DRIFTS, and DFT to determine optimal reaction conditions and mechanisms. TPSR data shows that with a 10% ZrO impregnated SiO 2 catalyst and under the presence of acetaldehyde, the conversion occurs at a much lower temperature and yields the most butadiene. DRIFTS data shows that the reaction occurs in neither only the gas phase nor the catalyst surface, and that the reaction only proceeds when the reactants exist at both locations. Finally, DFT data shows that singular and dimer ZrO sites exists on the catalyst surface in 4 and 5 fold coordination to facilitate the reaction. Future research will use DRIFTS to study the steady state conversion of ethanol at temperatures and conditions previously determined by TPSR. DFT will be used to simulate the reaction mechanisms to compare with DRIFTS data and to calculate the reaction’s energy barriers.
Traumatic brain injury (TBI) is a major risk factor for the development of epilepsy, or epileptogenesis. Approximately 1.5 million people in the United States sustain a TBI annually. Insulin-like Growth Factor-I (IGF-I) is found in the cerebrospinal fluid of healthy individuals, and following head injury, IGF-I levels are elevated in the brain tissue. Akt-mTOR and MAPK are downstream targets of IGF-I signaling that are activated after brain injury. However, both brain injury and mTOR are linked to epilepsy, raising the possibility that IGF-I may be epileptogenic. Here, we considered the role of IGF-1 in development of epilepsy after TBI using controlled cortical impact (CCI) in vivo model of brain trauma and organotypic hippocampal cultures in vitro model of epileptogenesis. We found that IGF-I signaling activated the Akt-mTOR pathway after brain injury, and contributed to epileptogenesis.Modulation of the IGF-I-Akt-mTOR signaling may form the basis of new antiepileptic treatments.
Michelle Fedun, Cathy Fletcher, Leigh Heinbokel, and Kristen Mejia
2016 People's Choice
Although biosand filters (BSFs) have been implemented in over 55 countries to provide safe drinking water, the necessity of operating filters on a daily basis has raised questions about filter efficacy after a period of abandonment (e.g., due to travels away from home or school vacations when students/faculty are not present to use institutional filters every day). Presently, the safe recommendation for abandoned filters is to deconstruct and rebuild. An assessment of the effectiveness of revitalized BSFs was conducted on two full-scale concrete BSFs, two 5-gallon bucket BSFs, and two 2-gallon bucket BSFs that were abandoned for two years. The filters were revitalized by rehydration (as needed), swirl-and-dump sand cleaning, tubing disinfection, and flushing. The performance of the revitalized filters was compared to that of two newly built concrete filters by measuring influent and effluent levels of Escherichia coli, Cryptosporidium parvum oocysts, and turbidity. Influent water was collected from a local creek to provide adequate nutrients to support biolayer development and to emulate field use. The log removal of E. coli and C. parvum by each filter was calculated by testing the two subsequent effluents following each spike. In addition, turbidity of each influent and effluent was measured to determine percent reduction. Flow rates of the filters, as well as water quality measurements of influent and effluent water (i.e., conductivity, phosphates, ammonia, total nitrogen), were evaluated weekly. The data show that revitalized BSFs are comparable to newly built filters, simplifying the continued use of drinking water treatment systems in developing nations.
2016 Honorable Mention
Sapphire (α-Al2O3) thin films can have applications as optical and scratch-resistant coatings, as well as in microelectronics. Typical sapphire substrate fabrication requires the material be in the molten state at temperatures above 2000°C. This study examines the crystallization of amorphous atomic layer deposited (ALD) alumina thin films at low temperatures (950-1050°C) by seeded lateral epitaxy. Decoration of the film with sapphire nanoparticle seeds before annealing provides nucleation sites for crystal growth. The growth rate of these grains was observed to be direction dependent according to the orientation of the nanoparticles. We also show the dependence of crystal growth rate on substrate thickness and stress state.
Assessment of iron oxide paint pigments recovered from acid mine drainage through selective precipitation
Acid mine drainage (AMD) and its elevated concentrations of heavy metals are a widespread source of water pollution throughout Pennsylvania. Current AMD treatment methods are costly to operate and maintain due to the large volumes of waste sludge produced as a byproduct of treatment. The sludge requires regular removal and disposal yet has no practical use or commercial value. New resource recovery methods of AMD treatment aim to reduce waste by extracting metal contaminants in alternate usable forms which can be marketed and sold to recoup treatment costs. In particular, the iron loadings characteristic of AMD hold potential as vast untapped sources of iron oxides, commonly used in inorganic paints and pigments. Following a series of proof-of-concept experiments, a variety of iron oxide powders were successfully prepared from natural and synthetic AMD samples through the selective precipitation of iron along with drying and milling processes. Variables such as pH, temperature, alkaline addition rate and drying duration were controlled and varied, and their effects on oxide morphology and composition were observed using x-ray diffraction and scanning electron microscope technology. Powders were mixed with binder and successfully used as paint, and were evaluated based on color, tinting strength, and phases of iron oxide present. Treated natural AMD samples were found to meet NPDES limits. Further exploration into the kinetics of the selective precipitation process and its effects on iron oxide morphology is currently underway, in an effort to produce improved pigments at cheaper costs.
Jay Fraser and Kathryn Kundrod
2015 People's Choice
Once a patient is diagnosed as HIV-positive, tests of viral load (the concentration of virus circulating in the blood) are performed routinely in order to monitor disease progression and ensure treatment effectiveness. Currently, there is no procedure to measure viral load in a point-of-care setting. It often takes upwards of two weeks to receive a patient’s viral load results from central facilities, making it difficult for doctors to make treatment decisions or adjust medication in the case of drug resistance. Microfluidic technology offers the ability to analyze small sample volumes, encouraging the development of point-of-care systems for viral diagnostics. A microfluidic viral load analyzer needs to separate the HIV virions from plasma and quantify the targets. The small size of virions limits the use of traditional, flat-bed, immunoaffinity microfluidic devices. Thus, here we validate the effectiveness of a nanoporous filtration matrix to isolate pseudo HIV virions from a solution . Adapting the methods of da la Escosura and Muniz, virions are tagged with gold nanoparticles, and the virion-gold complexes are augmented with silver deposition, increasing the volume that the complexes occupy within the capture membrane . These aggregates block flow of an ionic solution through the membrane pores. The reduction of ion flow as viral capture increases can be quantified through cyclic voltammetric analysis. Initial experiments show a correlation between a decrease in peak current and an increase in simulated viral load (n=4, R2=0.934). This system, once optimized, has the potential to perform viral load quantification in a point-of-care setting. 1. Surawathanawises, Krissada. “Polymeric Nanoporous Structures Integrated into Microfluidic Device for HIV Detection,” PhD Dissertation, Lehigh University, Bethlehem, PA, 2014. 2. de la Escosura-Muniz, A.; Merkoci, A. “A Nanochannel/Nanoparticle-Based Filtering and Sensing Platform for Direct Detection of a Cancer Biomarker in Blood,” Small, 2011.
The objective of this research is to develop a simplified and accurate computational model for DNA behavior that can be used to provide molecular level understanding of experimentally observed phenomena. The ultimate goal is to apply this predictive DNA model for improving design principles in nanotechnology applications such as sequence-dependent separation of carbon nanotubes from a mixture and DNA-mediated particle assembly to create novel hierarchical structured materials. In principal, fully detailed all-atom models that account for every atom in the system including solvent atoms can provide the most accurate representation. These models, however, have computational limitations both in system size and timescale of interesting processes that can be reached. In order to observe the phenomena of interest, a condensed model is required. We propose a coarse-grained model in which each nucleotide is represented by only two spherical beads – for backbone and base atoms. In this model, the effective interactions between base beads are derived from all-atom simulation data for both base-base stacking and base-base hydrogen bonding. (1) The model, which is not built around a particular reference state unlike other coarse-grained DNA models, is able to describe the structural and thermodynamic properties of both single and double strand DNA including hairpin and duplex formation. (2) Shankar, Jagota, and Mittal. "DNA Base Dimers Are Stabilized by Hydrogen-Bonding Interactions Including Non-Watson–Crick Pairing Near Graphite Surfaces." The Journal of Physical Chemistry B 116.40 (2012): 12088-12094. Boyer, Ding, and Mittal. “A Novel Coarse-Grained Model for dsDNA and ssDNA.” (to be submitted)
2014 Second Place; People's Choice
Sapphire, a crystalline type of alumina (Al2O3), is a ceramic compound with several industrial applications. It is commonly used as a substrate wafer for compound semiconductor growth and LED manufacturing. In addition, it is often used as an optical window due to its high degree of optical transparency. The growth of large grain or single crystal sapphire however, is a time- and energy-intensive process, motivating new growth techniques. This investigation develops alternative pathways to produce large grained sapphire films on a variety of substrates. Atomic layer deposition (ALD) is an emerging growth technique capable of deposition of amorphous alumina with precise thickness control. Annealing of amorphous alumina films typically requires very high temperatures and results in nanoscopic crystals. We have demonstrated that by placing nanoparticle sapphire seeds on the amorphous ALD alumina, crystallization can be induced at far lower temperatures, resulting in large grains (several microns in diameter). Crystallization was observed at temperatures as low as 900 °C. By measuring the growth rates of the crystals at various temperatures, the growth temperature and time can be optimized to produce fully polycrystalline sapphire films on a variety of substrates.
2013 People's Choice
According to the Center of Disease Control and Prevention, epilepsy affects 2.2 million Americans, and 65 million people worldwide. Traumatic brain injury is one of the major risk factors causing epileptogenesis, or the development of epilepsy taking place in the latent period between injury and the appearance of spontaneous seizures. In order to prevent epilepsy from developing, therapeutic approaches need to target molecular events that lead from injury to the formation of epileptic circuits. It has been discovered that the mTOR inhibition suppresses abnormal neural circuit reorganization and may reduce spontaneous seizures in some cases, but mTOR inhibition by itself is not enough to completely prevent the onset of spontaneous seizures. This suggests that other signaling pathways and cascades are involved in epileptic activity in the brain. Insulin-like Growth Factor-1 (IGF-1) levels are elevated in brain tissue following head injury.Previous results suggest IGF-1 has pro-epileptogenic effect in an organotypic hippocampal model of posttraumatic epilepsy. It is known that the binding of IGF-1 to IGF-1 receptors (IGF -1 R) leads to activation of MAPK and PI3K signaling cascades, however it is not clear whether IGF-1 activates mTOR, or operates in parallel to PI3K-Akt-mTOR cascade through activation of MAPK. Each of these molecules may be promising targets for anti-epileptogenic drugs, however a more detailed understanding of how these pathways are activated, along with the time sequence of molecular events is necessary. In this study, Western Blot analysis was used in order to measure levels of phosphorylation of Akt, MAPK, and S6 (a marker of mTOR activation), during early post injury period and latent period with and without IGF-1 in the culture medium. Following this study, we plan to determine the timeline of the signaling cascade and will make conclusions on the effects of IGF-1 on the different steps in the cascade with the ultimate goal of developing an effective antiepileptogenic treatment.
In Vitro Examination of Poly(glycerol sebacate) Degradation Kinetics: Effects of Porosity and Cure Temperature
Poly(glycerol sebacate) (PGS) is a biodegradable and biocompatible elastomer that has been used in a wide range of biomedical applications, including drug delivery, microfluidic devices, and tissue engineering scaffolds. The material possesses similar mechanical properties to those of soft body tissues and is mechanically tunable by altering cure temperature. An increased cure temperature correlates to an increased amount of cross-linking, resulting in a greater elastic modulus. While a porous format is preferred for scaffolds, to allow cell ingrowth, PGS degradation has been primarily studied in a nonporous format. The purpose of this research was to investigate the degradation of porous PGS at three frequently used cure temperatures: 120°C, 140°C, and 165°C. The thermal, chemical, mechanical, and morphological changes were examined using thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, compression testing, and scanning electron microscopy. Over the course of the 16-week degradation study, the samples’ pores collapsed. The specimens cured at 120°C demonstrated the most degradation and became gel-like after 16 weeks. Thermal changes were most evident in the 120°C and 140°C cure PGS specimens, as shifts in the melting and recrystallization temperatures occurred. Porous samples cured at all three temperatures displayed a decrease in compressive modulus after 16 weeks. This in vitro study helped to elucidate the effects of porosity and cure temperature on the biodegradation of PGS and will be valuable for the design of future PGS scaffolds.
2013 Second Place
Hydrogen passivation is an important step in the fabrication of optoelectronic devices. Passivation isolates components on a semiconductor substrate by electronically and/or photonically deactivating doped regions. Hydrogen has been identified as a passivating species for n- and p- type III-V semiconductor materials. The substrate is exposed to hydrogen plasma, which diffuses through the doped film. The hydrogen reacts with dopant atoms to form neutral complexes, thereby passivating the region. The purpose of this work is to create a predictive computer simulation using a physically-based theoretical model and to validate the simulation against experimental data. The model involves both the reaction and diffusion of passivating species with dopant atoms, subject to charge-induced field effects. Computational work has focused on creating a stable numerical simulation using MATLAB, which individually tracks all species concentrations and electrical potential as a function of time, position and system parameters. This yields physical insight into the passivation process. The theoretical model has been implemented for p-type material using a finite difference scheme, employing an iterative method for solving the time-evolution of the species in the passivated region. Simulation results show excellent agreement with experiments using Zn-doped material. Work continues to focus on increasing the robustness of the simulation to handle more physically-complex scenarios, including annealing, heterostructures, and both n-type and mixed n/p-type substrates.
Michael Beddow and Matthew Tessitore
2013 Third Place
The Phone Analytics for Ground Crew Efficiency (PAGE) project revolved around researching how mobile G.P.S. technologies can help PPL better track its groundcrews on a day-to-day basis. Specifically, PPL was interested in capturing statistics such as driving habits, work site locations, and damage reports in a much more automated and granular fashion. The first half of the project consisted of researching business requirements, possible project issues, and designing an application infrastructure, whereas the second half consisted of the programming and deployment of the team’s solution.
2011 Second Place
Katherine Glass-Hardenbergh and Sushan Zheng
2011 Honorable Mention
2011 Honorable Mention
Alexander J. Bourque and Jonathan S. Rosen
2011 Honorable Mention
Andrew Woodward, Kyle Schreiner, Mary Nunley, and Danny Cohen
2011 People's Choice
2010 Third Place
2010 People's Choice
Epoxy resins filled with silica are used in a wide array of applications. When used in microelectronic packaging, chiefly as an underfill encaplsulant, it is critical that such epoxy resins possess low viscosity as well as high fracture toughness. Traditionally, micron-size silica fillers are used but there is much interest in the use of nanometer size fillers as the feature size on silicon chips decreases. In this study, the rheological behavior of an epoxy resin containing nanosilica fillers was characterized in steady state shear using a Rheometerics ARES rheometer equipped with a Couette fixture. Two types of nanosilica particles were examined as potential fillers(22nm and 168nm in diameter) as well as mixtures of both. Interestingly, the unimodal formulations exhibited reduced viscosities larger than those predicted from Einstein's equation, thus suggesting significant interactions between particles. Note that shear rate studies did not reveal the presence of a yield stress nor structure formation. Bimodal mixtures of nanosilica were also explored as a possible means to reduce the viscosity for a given nanosilica content. Initial results look promising even though the nanosilica content is lower than what is traditionally used in these systems.
Daniel Faro and Casey Parker
2010 Second Place
The proposed work aims to develop novel membrane technology for efficient, high selective high-temperature carbon dioxide and simultaneous carbon dioxide and sulfur dioxide capture. Realization of high-performance membranes for such applications is widely recognized as a potentially revolutionary technology for continuous carbon capture. The research focuses on two materials: sodium oxide promoted alumina and silicalite-1. The main objectives involve synthesizing and characterizing the materials. Membranes will then be modeled, synthesized, and characterized. Success of this program should lead to novel practical and fundamental insight and, potentially, the establishment of a new paradigm for membrane based carbon sequestration.
Directed Differentiation of Oligodendrocyte Precursor Cells Using Rationally Designed Solid State Peptide Materials
2010 First Place
Oligodendrocytes are neuroglial cells whose function is to support and myelinate axons in the CNS. Oligodendrocytes have been found to arise from oligodendrocyte precursor cells (OPCs) during late embryogenesis and early post natal development. A single oligodendrocyte can myelinate as many as 40 or more different axons, wrapping the axon with between 20 and 200 layers of highly modified membrane processes1. The differentiation of OPCs into myelin-synthesizing oligodendrocytes is not well understood, and research suggests that cues for differentiation involve mechanical and chemical signaling from astrocytes and neurons. Many proteins are known to be involved in the migration, proliferation, survival, and differentiation of oligodendrocyte precursors, but their specific roles are not well defined or understood. A better understanding of the mechanism through which these proteins affect the differentiation of OPCs will allow us to more effectively differentiate OPCs to oligodendrocytes, allowing us to better assess the potential for using OPCs as a neurological therapy. The cells used in this study are CG4s, a bipotential glial cell line capable of differentiating into oligodendrocytes2. Various peptide materials are being used to enhance differentiation of CG4 OPCs into mature oligodendrocytes with myelinating capabilities as well as to support mature oligodendrocytes in culture for further study.
2009 Honorable Mention