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2016

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Articles 2191 - 2220 of 9604

Full-Text Articles in Engineering

Design Optimization Of A Stochastic Multi-Objective Problem: Gaussian Process Regressions For Objective Surrogates, Juan Sebastian Martinez, Piyush Pandita, Rohit K. Tripathy, Ilias Bilionis Aug 2016

Design Optimization Of A Stochastic Multi-Objective Problem: Gaussian Process Regressions For Objective Surrogates, Juan Sebastian Martinez, Piyush Pandita, Rohit K. Tripathy, Ilias Bilionis

The Summer Undergraduate Research Fellowship (SURF) Symposium

Multi-objective optimization (MOO) problems arise frequently in science and engineering situations. In an optimization problem, we want to find the set of input parameters that generate the set of optimal outputs, mathematically known as the Pareto frontier (PF). Solving the MOO problem is a challenge since expensive experiments can be performed only a constrained number of times and there is a limited set of data to work with, e.g. a roll-to-roll microwave plasma chemical vapor deposition (MPCVD) reactor for manufacturing high quality graphene. State-of-the-art techniques, e.g. evolutionary algorithms; particle swarm optimization, require a large amount of observations and do not …

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Nanobubbles Provide Theranostic Relief To Cancer Hypoxia, Christopher M. Long, Pushpak N. Bhandari, Joseph Irudayaraj Aug 2016

Nanobubbles Provide Theranostic Relief To Cancer Hypoxia, Christopher M. Long, Pushpak N. Bhandari, Joseph Irudayaraj

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hypoxia is a common motif among tumors, contributing to metastasis, angiogenesis, cellular epigenetic abnormality, and resistance to cancer therapy. Hypoxia also plays a pivotal role in oncological studies, where it can be used as a principal target for new anti-cancer therapeutic methods. Oxygen nanobubbles were designed in an effort to target the hypoxic tumor regions, thus interrupting the hypoxia-inducible factor-1α (HIF-1α) regulatory pathway and inhibiting tumor progression. At less than 100nm, oxygen nanobubbles act as a vehicle for site-specific oxygen delivery, while also serving as an ultrasound contrast agent for advanced imaging purposes. Through in vitro and in vivo studies, …

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Quantification And Characterization Of Aluminum Distributions In Commercial Beta And Mordenite Zeolites By Cobalt Exchange, Rebecca L. Reitzel, Claire T. Nimlos, Rajamani Gounder Aug 2016

Quantification And Characterization Of Aluminum Distributions In Commercial Beta And Mordenite Zeolites By Cobalt Exchange, Rebecca L. Reitzel, Claire T. Nimlos, Rajamani Gounder

The Summer Undergraduate Research Fellowship (SURF) Symposium

The aluminum distribution throughout the zeolite framework determines the structural, ion-exchange and catalytic properties of the zeolite. Several methods have been proposed to control the Al distribution, but in order to accurately assess these methods a procedure is needed to quantify Al distribution in various zeolite frameworks. Co2+ ions exchange onto the zeolite framework at Al pairs, and atomic absorbance spectroscopy (AAS) can be used to quantify the number of exchanged Co2+ ions and, in turn, the overall number of Al pairs. Each framework exhibits differences in pore size and channel configuration which affect the equilibrium conditions needed …

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Reward Modulated Spike Timing Dependent Plasticity Based Learning Mechanism In Spiking Neural Networks, Shrihari Sridharan, Gopalakrishnan Srinivasan, Kaushik Roy Aug 2016

Reward Modulated Spike Timing Dependent Plasticity Based Learning Mechanism In Spiking Neural Networks, Shrihari Sridharan, Gopalakrishnan Srinivasan, Kaushik Roy

The Summer Undergraduate Research Fellowship (SURF) Symposium

Spiking Neural Networks (SNNs) are one of the recent advances in machine learning that aim to further emulate the computations performed in the human brain. The efficiency of such networks stems from the fact that information is encoded as spikes, which is a paradigm shift from the computing model of the traditional neural networks. Spike Timing Dependent Plasticity (STDP), wherein the synaptic weights interconnecting the neurons are modulated based on a pair of pre- and post-synaptic spikes is widely used to achieve synaptic learning. The learning mechanism is extremely sensitive to the parameters governing the neuron dynamics, the extent of …

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Transport Contaminant In Flowing Water For Improving Water Quality, Ghassani Feta Adani, Antoine Aubeneau, Carlo Andrej Alviar, Xuqing Xiong, Shizhang Wang Aug 2016

Transport Contaminant In Flowing Water For Improving Water Quality, Ghassani Feta Adani, Antoine Aubeneau, Carlo Andrej Alviar, Xuqing Xiong, Shizhang Wang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Clean freshwater is fundamental to sustain human activities and the aquatic life. However, cities, industries, and agriculture wastes deteriorate water quality. For example, released fertilizer induces excess algal growth. This leads to major ecological problems such as eutrophication of freshwater ecosystems which has not only a great environmental cost impact, but can also affect the health and sustenance living of the people. This project investigates the transport of nitrate, a major plant fertilizer, in flowing freshwater. Streams and rivers can transform nitrate, thus mitigating its impact. Most of the biogeochemical reactions involved in nitrate removal take place where microorganisms usually …

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Haptic Foot Feedback For Kicking Training In Virtual Reality, Hank Huang, Hong Tan Aug 2016

Haptic Foot Feedback For Kicking Training In Virtual Reality, Hank Huang, Hong Tan

The Summer Undergraduate Research Fellowship (SURF) Symposium

As means to further supplement athletic performances increases, virtual reality is becoming helpful to sports in terms of cognitive training such as reaction, mentality, and game strategies. With the aid of haptic feedback, interaction with virtual objects increases by another dimension, in addition to the presence of visual and auditory feedback. This research presents an integrated system of a virtual reality environment, motion tracking system, and a haptic unit designed for the dorsal foot. The prototype simulates a scenario of virtual kicking and returns haptic response upon collision between the user’s foot and virtual object. The overall system was evaluated …

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X-Ray And Laser Investigation Of High Pressure Sprays, Wilbert C. Slowman, Lane E. Shultz, Terence R. Meyer Aug 2016

X-Ray And Laser Investigation Of High Pressure Sprays, Wilbert C. Slowman, Lane E. Shultz, Terence R. Meyer

The Summer Undergraduate Research Fellowship (SURF) Symposium

The diagnostics of multiphase flows is important to understand the correlation of parameters such as nozzle geometry, flow velocity, liquid breakup characteristics, atomization, and mass distribution. Investigation of each of these parameters can lead to various improvements on design and optimization, for example, of combustion in gas turbines and rocket engines. For this project, the X-ray and optical diagnostics of multiphase flows in propulsion is investigated for high pressures. Two x-ray tube sources are used to illuminate the spray, and the images are captured on phosphor plates coupled to high-speed cameras. Reconstruction of the mass distribution is accomplished using computer …

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Dynamic Behavior Of A Clamped-Clamped Bi-Stable Laminate For Energy Harvesting, Ajay V. Kumar, Andres F. Arrieta Ph.D., Myungwon Hwang Aug 2016

Dynamic Behavior Of A Clamped-Clamped Bi-Stable Laminate For Energy Harvesting, Ajay V. Kumar, Andres F. Arrieta Ph.D., Myungwon Hwang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Multi-stable laminates have many applications in morphing structures, energy harvesting devices, and metamaterials due to the specific characteristics attributed to the exhibited stable states. Changes between stable states allow for large deflections, on-demand variation of the stiffness of compliant structures embedded within these elements, and control of effective dynamic properties in periodic lattices. These changes in state can be accessed via a snap-through instability triggered by introducing a well-defined activation energy. The resulting oscillations could enable broadband energy harvesting via piezoelectric transduction and resistive circuits. In this paper, a clamped-clamped bi-stable laminate is studied to understand the behavior of the …

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Evaluation Of Strain Distortion Correction Protocol Using Scanning Electron Microscopy And Digital Image Correlation, Alexandra Mallory, Alberto Mello, Michael Sangid Aug 2016

Evaluation Of Strain Distortion Correction Protocol Using Scanning Electron Microscopy And Digital Image Correlation, Alexandra Mallory, Alberto Mello, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

Scanning electron microscopy in combination with digital image correlation (SEM-DIC) is a useful technique for measuring strain in materials at the micro-scale. In particular, it can be used to identify micro-scale strain localizations that are the precursor to material failure. While SEM produces high resolution images of the microstructure, the images also contain a large amount of distortion that, during DIC, will result in distorted strain values that require correction. In this project, a nickel-based alloy underwent cyclic mechanical fatigue at three different high temperatures to a targeted maximum strain. Scanning electron microscopy imaging was done on a 200x150μm area …

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Characterizing Hmx/Ap Cocrystal Propellant Through Planar Laser Induced Fluorescence, Seth M. Nielsen, Michael S. Powell, Steven F. Son Aug 2016

Characterizing Hmx/Ap Cocrystal Propellant Through Planar Laser Induced Fluorescence, Seth M. Nielsen, Michael S. Powell, Steven F. Son

The Summer Undergraduate Research Fellowship (SURF) Symposium

Energetic cocrystals, or energetic materials that consist of two or more components that form a unique crystalline structure with unique properties, are currently being investigated as a possible method for decreasing the sensitivity of high energy density explosives for use in powerful solid composite propellants. Fuels more powerful than those in current use have not been practical because of their increased safety hazard due to higher sensitivity to being ignited. This has been one of the barriers that has prevented solid composite propellants from seeing significant improvements in performance. This study is an attempt to characterize a cocrystal of HMX …

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Energy Transfer In Cdse Nanoplatelet Superlattices, Kelly Wang, Jordan Snaider, Libai Huang Aug 2016

Energy Transfer In Cdse Nanoplatelet Superlattices, Kelly Wang, Jordan Snaider, Libai Huang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Two-dimension CdSe semiconductor nanoplatelets (NPLs) exhibit unique, highly desirable optical and electronic properties, such as large absorption crossection and bright emission. Fӧrster resonance energy transfer (FRET) between NPLs is responsible for the utility of these NPLs in fields such as lasing, lighting, solar energy, and sensing. Here we study energy transfer processes in NPL superlattices using photoluminescence (PL) and time resolved PL (TRPL) spectroscopic methods. Information on the effect of thickness of NPL is obtained through correlating PL and TRPL spectra of CdSe superlattices with AFM measurements. PL spectrum showed narrow fluorescence and absorption peaks at room temperature corresponding to …

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A Compact System For Photon Counting Based On Silicon Photomultiplier, Youngwoo Cho, Youngkee Jung, Euiwon Bae Aug 2016

A Compact System For Photon Counting Based On Silicon Photomultiplier, Youngwoo Cho, Youngkee Jung, Euiwon Bae

The Summer Undergraduate Research Fellowship (SURF) Symposium

A compact and portable detection system is necessary to measure the amount of pollutant from environmental sample by detecting and quantifying the light emitted by bioluminescent reporters. This silicon photomultiplier based project is hoping to acquire even more accurate data at a far lower light level than previously developed smartphone based system. After pre-amplification and comparator, the signal is separated from the internal noise present in the overall circuit. Next, the microcontroller counts the number of pulses generated by the comparator in a set amount of time and transfers the data to the Bluetooth module for the smartphone to receive …

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Production Of Porous Alginate Substrates Via Membrane Emulsification For Pharmaceutical Applications, Genesis D. Correa-Rivera, David A. Acevedo, Zoltan K. Nagy Aug 2016

Production Of Porous Alginate Substrates Via Membrane Emulsification For Pharmaceutical Applications, Genesis D. Correa-Rivera, David A. Acevedo, Zoltan K. Nagy

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Food and Drug Administration (FDA) released in 2013 a report that established the pharmaceuticals current good manufacturing practices for the 21st century. This report encourages the creation of new technology in the pharmaceutical industry. Therefore, this research aims to develop a reliable method to produce porous polymers particles to be used in a novel continuous crystallization in porous substrate. The aim of the current work is to create porous polymer microspheres with uniform particle size distribution using a commercially available membrane emulsification system. In the present study, the emulsification was made using a dispersed phase composed of miglyol …

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Gdd(Growth Degree Day) Module For Vinsense Visual Analytics System, Pradeep K. Lam, David Ebert , Phd, Jiawei Zhang Aug 2016

Gdd(Growth Degree Day) Module For Vinsense Visual Analytics System, Pradeep K. Lam, David Ebert , Phd, Jiawei Zhang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Limited resources and increasing costs require vineyards to develop optimized methods of planting, growing, and harvesting crops in order to ensure max yield and stay competitive in the marketplace. Data from sensors planted within the soil paired with weather reports and observation data from farmers could help develop competitive farming strategies. While automatic computation models are usually a black box that cannot explain how the input data are transformed into output, the farmers require an approach that allows them to interactively manipulate and supervise the computation process. The VinSense project was developed for this purpose. In this paper, we focus …

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Effect Of Conveying And Distributive Mixing Elements On Breakage Phenomenon In Twin Screw Granulation, Jiayu Li, Shankali U Pradhan, Carl Wassgren Aug 2016

Effect Of Conveying And Distributive Mixing Elements On Breakage Phenomenon In Twin Screw Granulation, Jiayu Li, Shankali U Pradhan, Carl Wassgren

The Summer Undergraduate Research Fellowship (SURF) Symposium

Twin screw wet granulation (TSG) is gaining more attention and becoming an important process in the pharmaceutical industry. The process is widely implemented because of its flexibility, short residence time, and small equipment footprint. Past studies have shown that screw elements can have a significant impact on the performance of the TSG process. In addition, these studies identified that breakage of wet mass is a significant step in the process. Currently there is no literature that focuses on the effect of each screw element on the breakage process. In this work, experiments have been designed to isolate the breakage process …

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Exploring How Haptics Contributes To Immersion In Virtual Reality, Dimcho Zhelyazkov Karakashev, Hong Z. Tan Aug 2016

Exploring How Haptics Contributes To Immersion In Virtual Reality, Dimcho Zhelyazkov Karakashev, Hong Z. Tan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Virtual Reality (VR) has been around for more than fifty years but the technology hasn’t reached practical usability until very recently. With the current head-mounted display (HMD) technology and an abundance of investment in VR startups, we have finally reached at the point where it is possible to simulate complex virtual environments that feel immersive. A major problem with virtual reality is that everything looks real but you can not touch and feel virtual objects. We are focusing on developing a device that will allow users to feel what they touch in VR. We developed a hand-held interface and an …

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Investigation Of Aluminum Foams And Graphite Fillers For Improving The Thermal Conductivity Of Paraffin Wax-Based Phase Change Materials, Javieradrian Ruiz, Amy Marconnet, Yash Ganatra, John Howarter, Alex Bruce Aug 2016

Investigation Of Aluminum Foams And Graphite Fillers For Improving The Thermal Conductivity Of Paraffin Wax-Based Phase Change Materials, Javieradrian Ruiz, Amy Marconnet, Yash Ganatra, John Howarter, Alex Bruce

The Summer Undergraduate Research Fellowship (SURF) Symposium

Passive thermal management with phase change materials (PCMs) has become the one of the most promising methods to cool cell phone processors due to the relatively simple implementation and profound impact on processor temperatures. Enhancing the thermal properties of conventional PCMs, mainly thermal conductivity and latent heat storage, allows for an overall improved thermal management system. This study aims to improve the thermal conductivity of paraffin wax (a typical commercial PCM) by the introduction of an expanded graphite (EG) filler to form a paraffin wax composite, and then infiltration of the EG/paraffin composite into an aluminum foam matrix. The thermal …

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Leveraging Smart Infusion Pump Data For Workflow, Patient Care And Usability Improvement In Human Factors, Yan Ni Ding, Denny Yu, Poching Delaurentis, Kang-Yu Hsu, Joon Hong Kim Aug 2016

Leveraging Smart Infusion Pump Data For Workflow, Patient Care And Usability Improvement In Human Factors, Yan Ni Ding, Denny Yu, Poching Delaurentis, Kang-Yu Hsu, Joon Hong Kim

The Summer Undergraduate Research Fellowship (SURF) Symposium

Infusion pumps are medical devices that deliver fluids like medication, and nutrients in a precise, timely, and controlled manner that is critical to patient care. It is widely used in clinical settings especially in hospitals, nursing homes and sometimes at home. Smart infusion pumps technology are supposed to be reduce nurses’ workload, but due to the recurring number of alarms which disrupt the workflow of the infusion process, most nurses prefer to use the traditional infusion pumps or work-around the safety features of the smart pumps. Thus, the aim of this research is to leverage Smart Infusion Pump data to …

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Impact Of Microscope, Loupes, And Video Displays On Microsurgeons’ Risk For Musculoskeletal Injuries, Yiyu Shi, Denny Yu Aug 2016

Impact Of Microscope, Loupes, And Video Displays On Microsurgeons’ Risk For Musculoskeletal Injuries, Yiyu Shi, Denny Yu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Microsurgery is commonly performed with operating microscopes or loupes to repair traumatic injuries, damage from cancer surgery, etc.; however, the prolonged, awkward, and constrained postures from using these equipment puts microsurgeons at risk for musculoskeletal pain and injuries. An alternative heads-up displays may improve surgeons’ ergonomics by allowing microsurgeons to perform the procedure in a more comfortable and ergonomic position. The study compares the effect of microscope, loupes and video displays on postures during microsurgical targeting task. This study incorporated three steps to contrast displays. Firstly, 12 participants wearing six reflective markers completed a surgery simulation using all three displays, …

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How User's Visualization Literacy Relates To Their Cognitive Traits, Jiming Yang, Sukwon Lee, Ji Soo Yi Aug 2016

How User's Visualization Literacy Relates To Their Cognitive Traits, Jiming Yang, Sukwon Lee, Ji Soo Yi

The Summer Undergraduate Research Fellowship (SURF) Symposium

Researchers in the field of Information Visualization have suggested that users’ cognitive abilities would likely to affect their understanding of data visualizations and deeper exploration in the visualizations. However, the evidence is still scant to link between user’s visualization literacy and their cognitive traits. Thus, the research goal of this study is to explore how user’s visualization literacy and their cognitive traits are related. In particular, we focused on two cognitive traits: numeracy and need-for-cognition. In order to achieve the goal, first, we measured visualization literacy, numeracy, and need-for-cognition using existing instruments with 46 Amazon Mechanical Turk workers, and the …

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Modeling Of Ion/Target Interactions In Plasma Facing Components Of Fusion Reactor, Nicole Neto Godry Farias, Tatyana Sizyuk, Ahmed Hassanein Aug 2016

Modeling Of Ion/Target Interactions In Plasma Facing Components Of Fusion Reactor, Nicole Neto Godry Farias, Tatyana Sizyuk, Ahmed Hassanein

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nuclear fusion is a promising source of clean energy that can be one of the key future suppliers of the world’s increasing power demand. One of today’s main challenges faced by scientists and engineers regarding nuclear reactors is to design plasma-facing components (PFCs) that can withstand extreme conditions of temperature, pressure, and ions/particles irradiation. Material evolution and damage of PFCs are strongly related to the bombardment and diffusion processes of ions resulting from fusion fuel, i.e., deuterium and tritium and reaction products, i.e., helium. However, work is still needed in order to understand fuel diffusion in the presence of helium …

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Rapid Grain Boundary Mobility At Ambient Temperatures, Jarrod M. Lund, R Adam Bilodeau, Rebecca K. Kramer Aug 2016

Rapid Grain Boundary Mobility At Ambient Temperatures, Jarrod M. Lund, R Adam Bilodeau, Rebecca K. Kramer

The Summer Undergraduate Research Fellowship (SURF) Symposium

Understanding and measuring the influence of grain boundaries (planar defects in the crystalline structure of materials) and their motion has become a dominant aspect in materials research, with applications in additive manufacturing, fatigue prevention, and material modeling. However, modeling grain boundaries and grain boundary mobility (GBM) is difficult due to the high temperatures or external stresses, imaging solutions compatible with the material system, and long time-scales required to create measurable experimental results. In this paper, we introduce a novel material system that allows for easy and fast visualization of GBM. A drop of liquid metal eutectic gallium indium (eGaIn) placed …

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Fabrication And Evaluation Of Magnetic Micro Actuators For Implantable Self-Clearing Glaucoma Drainage Devices, Haritha Ramadorai, Hyunsu Park, Hyowon Lee Aug 2016

Fabrication And Evaluation Of Magnetic Micro Actuators For Implantable Self-Clearing Glaucoma Drainage Devices, Haritha Ramadorai, Hyunsu Park, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

According to the World Health Organization, glaucoma is the second leading cause of blindness in the world. It currently affects more than 2.7 million people in the United States alone and over 79.6 million people worldwide are estimated to be inflicted by this debilitating disease by 2020. Glaucoma patients are often characterized with elevated intraocular pressure (IOP) and are treated with implantation of glaucoma drainage devices (GDD) to maintain optimum IOP. Although initially effective at delaying glaucoma progression, contemporary GDD often lead to numerous complications and only 50% of implanted devices remain functional after 5 years. Biofouling is seen to …

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Bone Tissue Engineering: Scalability And Optimization Of Densified Collagen-Fibril Bone Graft Substitute Materials, John G. Nicholas, Lauren E. Watkins, Sherry L. Voytik-Harbin Aug 2016

Bone Tissue Engineering: Scalability And Optimization Of Densified Collagen-Fibril Bone Graft Substitute Materials, John G. Nicholas, Lauren E. Watkins, Sherry L. Voytik-Harbin

The Summer Undergraduate Research Fellowship (SURF) Symposium

Over 240 million people missing teeth worldwide experience lingering problems such as difficulty speaking and eating, undesirable aesthetics, and resorption of bone supporting neighboring teeth. The gold standard of treatment utilizes grafts to attach a function-restoring implant to supporting bone. Current graft materials suffer from problems including autologous donor site morbidity, long resorption time, incomplete integration with the maxillae or mandible, and structural weakness. Patient-specific, cellularized bone grafts may be a solution to these issues by accelerating and improving the quality of regenerated bone. Recently, encapsulation of mesenchymal stem cells within self-assembling type I collagen oligomer matrices has been shown …

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Experimental Testing And Validation Of P-Band Bi-Static Remote Sensing Of Soil Moisture In 137-138mhz Range, Xiangyu Qu, Yao-Cheng Lin, James L. Garrison Aug 2016

Experimental Testing And Validation Of P-Band Bi-Static Remote Sensing Of Soil Moisture In 137-138mhz Range, Xiangyu Qu, Yao-Cheng Lin, James L. Garrison

The Summer Undergraduate Research Fellowship (SURF) Symposium

Remote sensing using readily available communication signal transmitted by ORBCOMM satellites at very high frequency (VHF) range (137-138MHz) is a promising method for detecting the root zone soil moisture content. The radio wave reflectivity of soil is strongly correlated to soil moisture content. Therefore, if we were able to measure the reflectivity, we might be able to estimate the soil moisture content. In this preliminary study, we analyze direct signal data from the satellites to investigate and verify communication channels in frequency range of interest and their characteristics (bandwidth, pattern, etc.). The analysis of direct signal data is also used …

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Strength Of Reinforced Concrete Beams With High-Strength Steel, Brian C. Rogers, Aishwarya Puranam, Santiago Pujol Aug 2016

Strength Of Reinforced Concrete Beams With High-Strength Steel, Brian C. Rogers, Aishwarya Puranam, Santiago Pujol

The Summer Undergraduate Research Fellowship (SURF) Symposium

Structures are commonly made of reinforced concrete, which is a composite material made of concrete and steel reinforcement. Using high-strength steel, with yield stress larger than 100 ksi, could help reduce the quantity of steel required in structural members, thus reducing costs and improving constructability. The hypothesis being tested is that smaller quantities of high-strength steel reinforcement (HSSR) can be used in place of conventional steel in reinforced concrete beams while maintaining similar strength and deformation at failure. Two reinforced concrete beams with two different types of longitudinal steel reinforcement were constructed. The beams were 18 in. wide, 30 in. …

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Performance Of Tf-Vls Grown Inp Photovoltaic Cells, Junyan Shi, Yubo Sun, Peter Bermel Aug 2016

Performance Of Tf-Vls Grown Inp Photovoltaic Cells, Junyan Shi, Yubo Sun, Peter Bermel

The Summer Undergraduate Research Fellowship (SURF) Symposium

A grand challenge of photovoltaics (PV) is to find materials offering a promising combination of low costs and high efficiencies. While III-V material-based PV cells have set many world records, often their cost is much greater than other commercial cells. To help address this gap, thin-film vapor-liquid-solid (TF-VLS) grown Indium Phosphide (InP) PV cells have recently been developed, which both eliminate a key source of high costs and offer a direct bandgap of 1.34eV with potential to approach maximum theoretical efficiencies. However, the unanticipated phenomenon of open circuit voltage (Voc) degradation has prevented TF-VLS grown InP PV cells …

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Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. Mccrorie, Michael Sangid Aug 2016

Metamodels Of Residual Stress Buildup For Machining Process Modeling, Stuart B. Mccrorie, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

In the process of machining materials, stresses, called residual stresses, accumulate in the workpiece being machined that remain after the process is completed. These residual stresses can affect the properties of the material or cause part distortion, and it is important that they be calculated to prevent complications from arising due to the residual stresses. However, these calculations can be incredibly computationally intensive, and thus other methods are needed to predict the residual stresses in materials for quick decision-making during machining. By using metamodels - a method of representing data where few data points exist - we can achieve an …

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Effect Of Particle Concentration And Ac Electric Field Strength On Particle Trapping In Rapid Electrokinetic Patterning (Rep), Sixuan Li, Avanish Mishra, Steve Wereley Aug 2016

Effect Of Particle Concentration And Ac Electric Field Strength On Particle Trapping In Rapid Electrokinetic Patterning (Rep), Sixuan Li, Avanish Mishra, Steve Wereley

The Summer Undergraduate Research Fellowship (SURF) Symposium

Rapid Electrokinetic Patterning (REP) is an optoelectric technique for trapping and translating micro- and nanoparticles non-invasively. It uses a combination of laser-induced AC electrothermal flow and particle-electrode interactions in the presence of a uniform AC electric field. The trapping is governed by laser power, electric field strength, AC frequency and dielectric properties of the particle and the medium. A REP trap has an AC frequency, termed critical frequency, above which particles cannot be trapped. It is expected to be dependent on dielectric properties of the particle and the medium. However, we propose that the particle concentration and AC field strength …

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Characterization Of Left-Ventricular Thrombus Formation Using High Frequency Ultrasound, Kelsey A. Bullens, Arvin H. Soepriatna, Pavlos P. Vlachos, Craig J. Goergen Aug 2016

Characterization Of Left-Ventricular Thrombus Formation Using High Frequency Ultrasound, Kelsey A. Bullens, Arvin H. Soepriatna, Pavlos P. Vlachos, Craig J. Goergen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heart failure is a leading cause of death in the United States, and cardiac thrombus, a common morbidity associated with heart failure, significantly increases a patient’s risk of embolic events. The objective of this project is to characterize left-ventricular (LV) thrombus development using high frequency ultrasound imaging in a murine model. C57BL/6J wild-type mice (n=6) were injected intraperitoneally with iron dextran five times a week for six weeks to increase oxidative stress in the heart. Granulocyte-colony stimulating factor (G-CSF) was subcutaneously injected daily during the second week to initiate stem cell migration and stimulate endothelial cell activation, thus increasing the …

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