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Full-Text Articles in Engineering

Computational Catalysis: Creating A User-Friendly Tool For Research And Education, Kevin P. Greenman, Peilin Liao Aug 2018

Computational Catalysis: Creating A User-Friendly Tool For Research And Education, Kevin P. Greenman, Peilin Liao

The Summer Undergraduate Research Fellowship (SURF) Symposium

Catalysis is used in a significant portion of production processes in the industrialized world, including most processing of chemicals and fuels. This makes maximizing the efficiency of catalysts a high priority. However, the immense number of candidates for new catalysts precludes the possibility of testing all of them by experiments. Density functional theory (DFT) has been widely and successfully used to calculate material properties relevant to catalysis and to screen promising candidates for experimental testing, but there currently exists no publicly- available, user-friendly tool for performing these DFT calculations. This work details the development of such a tool for nanoHUB.org …


Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei Aug 2018

Thienoisatin Oligomers As N-Type Molecular Semiconductors, Natalie M. Kadlubowski, Xuyi Luo, Jianguo Mei

The Summer Undergraduate Research Fellowship (SURF) Symposium

Organic field effect transistors (OFETs) offer many advantages compared to traditional inorganic transistors, such as flexibility and solution processability. In this study we design and synthesize two thienoisatin-based organic semiconducting small molecules, then investigate their electronic properties in n-type OFETs. To introduce n-type charge transport, electron-withdrawing dicarbonitrile moieties were installed on thienoisoindigo and bis-thienoisatin molecules, which led to a quinoidal conjugation on thienoisoindigo, while maintaining an aromatic conjugation on the bis-thienoisatin. Following the syntheses, the molecules were characterized to determine highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels via cyclic voltammetry, as well as any potential …


Solid Solution Strengthened Fe Alloys, Sidharth Krishnamoorthi, Ruizhe Su, Yifan Zhang, Xinghang Zhang Aug 2018

Solid Solution Strengthened Fe Alloys, Sidharth Krishnamoorthi, Ruizhe Su, Yifan Zhang, Xinghang Zhang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Iron (Fe)-based alloys (such as steel) are widely used structural materials in industry. Numerous methods have been applied to improve their mechanical properties. In this study, we used a technique know as magnetron sputtering to deposit various Fe-based binary alloy coatings to investigate the influence of solutes on solid solution hardening. Several factors contribute to the solid solution hardening of the alloys, such as composition, atomic radius, modulus, and lattice parameter. After preliminary calculations and analysis, we selected several solutes, including molybdenum (Mo), niobium (Nb), and zirconium (Zr). The compositions of solutes were varied to be 2.5, 5, 8 atomic …


Thermophotovoltaic Devices: Combustion Chamber Optimization And Modelling To Maximize Fuel Efficiency, Arnold Chris Toppo, Ernesto Marinero, Zhaxylyk Kudyshev Aug 2018

Thermophotovoltaic Devices: Combustion Chamber Optimization And Modelling To Maximize Fuel Efficiency, Arnold Chris Toppo, Ernesto Marinero, Zhaxylyk Kudyshev

The Summer Undergraduate Research Fellowship (SURF) Symposium

Currently, 110 billion cubic meters of natural gas (primarily methane), a potent greenhouse gas, are flared off for environmental and safety reasons. This process results in enough fuel to provide the combined natural gas consumption of Germany and France. The research team developed a thermophotovoltaic device to convert thermal energy to electricity at a high efficiency using proprietary emitters and combustion system. With the current focus being fuel efficiency and the combustion process, the assembly was simulated using ANSYS Fluent modelling software and the following parameters were optimized: air/fuel ratios, flow rates, and inlet sizes. Simultaneously the heat transfer across …


Grain Boundary Motion Analysis, Jeremy Marquardt, Xiaorong Cai, Marisol Koslowski Aug 2018

Grain Boundary Motion Analysis, Jeremy Marquardt, Xiaorong Cai, Marisol Koslowski

The Summer Undergraduate Research Fellowship (SURF) Symposium

Grain growth is a mechanism to relax residual stresses in thin films. These grains grow out of the thin film surface and are known as whiskers. These whiskers can cause short circuits, so developing scalable and cost effective solutions would increase the reliability and utility of tin electronics. A popular of method of examining tin whiskering is microscopic simulation, as it provides an accurate and cost effective way to predict the consequences of proposed models. Specifically examining the evolution of grain boundaries, this paper aims to present the results of grain boundary motion simulations through a generalized program that streamlines …


High Performance Mortar With 100% Recycled Aggregate Using Titanium Dioxide Nanoparticles, Molly Schrager, Vito Francioso, Arjun Kadakia, Mirian Velay-Lizancos Aug 2018

High Performance Mortar With 100% Recycled Aggregate Using Titanium Dioxide Nanoparticles, Molly Schrager, Vito Francioso, Arjun Kadakia, Mirian Velay-Lizancos

The Summer Undergraduate Research Fellowship (SURF) Symposium

Concrete and mortar are materials commonly used in construction. Their main compounds are cement, aggregates (sand and gravel) and water. In an effort to increase the sustainability of these materials, the idea of using recycled aggregates from ground old concrete and using it to make mortar and concrete has gained more interest. It has two advantages: it reduces the need to mine for raw materials and lessens the amount of old and defective concrete that is typically put in landfills. But, the use of recycled concrete aggregate lowers the strength of mortars and concretes because the residual compounds in the …


Reliability Of Lead-Free Solder Joints Under Combined Shear And Compressive Loads, Ian Bernander, Travis Dale, Yuvraj Singh, Ganesh Subbarayan Aug 2018

Reliability Of Lead-Free Solder Joints Under Combined Shear And Compressive Loads, Ian Bernander, Travis Dale, Yuvraj Singh, Ganesh Subbarayan

The Summer Undergraduate Research Fellowship (SURF) Symposium

In electronic assemblies, solder joints are used to create electrical connections, remove heat, and mechanically support the components. When an electronic device is powered on, the solder joints and the board they are attached to heat up, expanding at different rates. Due to the difference in expansion, shear stress is imposed on the solder joints. As the device is powered on and off, this shear stress can eventually fracture the solder joint, causing the device to fail. Therefore, to increase the lifespan of electronics, it is important to investigate the mechanical properties of solder alloys. The present study investigates how …


Validation Of Wrinkling-To-Delamination Adhesion Measurement Technique, Allison Chau, Hyeyoung Son, Chelsea S. Davis Aug 2018

Validation Of Wrinkling-To-Delamination Adhesion Measurement Technique, Allison Chau, Hyeyoung Son, Chelsea S. Davis

The Summer Undergraduate Research Fellowship (SURF) Symposium

Polymer thin films have a wide range of applications that span several different industries. Their optical clarity as well as their mechanical rigidness result in their versatile use in applications such as contact lenses, wearable sensors, and flexible electronics. These applications require precise adhesion, so the need for a simple, quantitative adhesion measurement technique is critical. Several methods have already been developed that quantify the adhesion of flexible thin films attached to rigid substrates. However, when the thin films are rigid and the substrates compliant, these methods are insufficient. In the authors’ previous work, an adhesion measurement technique was developed …


Determining The Optimal Traffic Opening Time Using Piezoelectric Sensors, Adlan Amran, Yen-Fang Su, Na Lu Aug 2018

Determining The Optimal Traffic Opening Time Using Piezoelectric Sensors, Adlan Amran, Yen-Fang Su, Na Lu

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Indiana Department of Transportation (INDOT) requires a reliable method of determining the early age quality of concrete to improve traffic opening time. We propose to develop an in-situ method that enables an accurate, efficient, and non-destructive health monitoring of concrete using the electromechanical impedance (EMI) technique coupled with a piezoelectric sensor named Lead Zirconate Titanate (PZT). The test was conducted by mounting a PZT sensor on mortar samples. The PZT sensor was then excited by a voltage to track the strengthening of samples. The data obtained from the EMI technique was refined using the Root Mean Square Deviation (RMSD) …


Building Modern Cloud Accessible Tools For Materials Simulations, Nicholas J. Finan, Saaketh Desai, Samuel Reeve, Alejandro Strachan Aug 2018

Building Modern Cloud Accessible Tools For Materials Simulations, Nicholas J. Finan, Saaketh Desai, Samuel Reeve, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

In recent years, commercial computer systems have grown more user friendly, allowing for new users to quickly and easily make contributions. Unfortunately, this trend is not as apparent in the field of computational materials simulations. The tools used by researchers in this field have remained just as esoteric as the systems of the past. While the methods used in materials simulations continue to grow in complexity and accuracy, the user experience has been neglected entirely. This project aims to eliminate the need for hours spent adjusting file formats and searching for preexisting code, and instead allow researchers to focus on …


Developing Strategies To Toughen Bio-Inspired Adhesives, Narelli P. Narciso, Samuel Lee Huntington, Jonathan J. Wilker Aug 2018

Developing Strategies To Toughen Bio-Inspired Adhesives, Narelli P. Narciso, Samuel Lee Huntington, Jonathan J. Wilker

The Summer Undergraduate Research Fellowship (SURF) Symposium

Mussels and other marine creatures adhere very well in underwater environments, having the ability to withstand the force of the sea. These animals have inspired synthetic biomimetic adhesives for wet systems, presenting potential for biomedical applications. However, most current commercial adhesives tend to be brittle, not resisting repetitive movements. This study assesses toughening strategies to improve the mussel-inspired adhesives’ ductility while maintaining its strength. The strategies included altering the polymer’s chemical structure by changing the percentage of polyethylene glycol (PEG) in the molecule and by adding fillers, such as calcium carbonate, silica and nacre - a calcium carbonate compound found …


Spatial Variation Of Surface Residual Stress In Metallic Materials, Chengyang Zhang, David Bahr, Siavash Ghanbari, Raheleh Mohammad Rahimi Aug 2018

Spatial Variation Of Surface Residual Stress In Metallic Materials, Chengyang Zhang, David Bahr, Siavash Ghanbari, Raheleh Mohammad Rahimi

The Summer Undergraduate Research Fellowship (SURF) Symposium

Shot peening is commonly used to reduce fatigue failures in industrial parts by introducing compressive residual stress into the surface of a material. However, it is challenging to assess the performance of the parts without destroying them. Solving this problem requires a combined model that predicts both recrystallization and residual stress using experimental measurements and predictive computational modelling. Experiments were performed to prove that the surface properties of materials after thermal treatments can be accessed, and the spatial variation of residual stress in metallic materials, including the relationship between surface and subsurface behavior can be evaluated. This process involves investigating …


Tool For Correlating Ebsd And Afm Data Arrays, Andrew Krawec, Matthew Michie, John Blendell Aug 2018

Tool For Correlating Ebsd And Afm Data Arrays, Andrew Krawec, Matthew Michie, John Blendell

The Summer Undergraduate Research Fellowship (SURF) Symposium

Ceramic and semiconductor research is limited in its ability to create holistic representations of data in concise, easily-accessible file formats or visual data representations. These materials are used in everyday electronics, and optimizing their electrical and physical properties is important for developing more advanced computational technologies. There is a desire to understand how changing the composition of the ceramic alters the shape and structure of the grown crystals. However, few accessible tools exist to generate a dataset with the proper organization to understand correlations between grain orientation and crystallographic orientation. This paper outlines an approach to analyzing the crystal structure …


Comparison Of Pm-Hip To Cast Alloy 625 For Nuclear Applications, Alexander L. Bullens, Keyou Mao, Janelle P. Wharry, Esteban Bautista Aug 2017

Comparison Of Pm-Hip To Cast Alloy 625 For Nuclear Applications, Alexander L. Bullens, Keyou Mao, Janelle P. Wharry, Esteban Bautista

The Summer Undergraduate Research Fellowship (SURF) Symposium

PM-HIP, or Powder Metallurgy and Hot Isostatic Pressing, metals have been a low cost alternative to forged and cast structural metals within various industries. The nuclear industry has recently developed interest in PM-HIP alloys, but further research needs to be done to quantify their mechanical properties and characterize the microstructure. Specifically, we must understand the mechanical and microstructural evolution of PM-HIP materials after long-term operation at the elevated temperatures that PM-HIP components will experience in service. We focus on Ni-base alloy Inconel 625, and compare the PM-HIP version to the cast version. Our methodology consists of annealing samples to various …


Microstructure Evolution During Compaction Of Powder Blends, Ayush Giri, Marcial Gonzalez, Yasasvi Bommire Aug 2017

Microstructure Evolution During Compaction Of Powder Blends, Ayush Giri, Marcial Gonzalez, Yasasvi Bommire

The Summer Undergraduate Research Fellowship (SURF) Symposium

Powder compaction is a manufacturing technology used to transform powder particles into a solid material with unique anisotropic microstructure and low porosity. It is widely used by pharmaceutical companies to manufacture tablets with desired properties. These properties are the result of the microstructure obtained during the compaction process. Therefore, it is imperative to understand the mechanics underneath the constituent granular particles that eventually contribute to properties of the manufactured tablets. Computational simulation tools have been developed in the past to study powder compaction for pharmaceutical tablets. However, most of the already existing tools limit their scope to study individual particles …


Irradiation-Induced Nanocluster Evolution, Didier Ishimwe, Matthew J. Swenson, Janelle P. Wharry Aug 2017

Irradiation-Induced Nanocluster Evolution, Didier Ishimwe, Matthew J. Swenson, Janelle P. Wharry

The Summer Undergraduate Research Fellowship (SURF) Symposium

Oxide dispersion strengthened steel (ODS) and commercial ferritic-martensitic (F-M) alloys are widely accepted candidate structural materials for designing advanced nuclear reactors. Nanoclusters embedded in the steel matrix are key microstructural features of both alloy types. Irradiation from nuclear fusion and fission affects the morphology of these nanoparticles, altering the performance of the alloys and potentially decreasing their usable lifetime. Thus, it is important to understand the effect of irradiation on these nanoparticles in order to predict long-term nuclear reactor performance. It was found that the evolution of nanoclusters in each material is different depending on the experimental irradiation parameters. The …


Understanding Powder Compaction With Single Particle Measurements, Wentao Chen, Ankit Agarwal, Marcial Gonzalez Aug 2017

Understanding Powder Compaction With Single Particle Measurements, Wentao Chen, Ankit Agarwal, Marcial Gonzalez

The Summer Undergraduate Research Fellowship (SURF) Symposium

Powder compaction is the process of transforming granular media into a solid body with a high relative density (low porosity) and a unique anisotropic microstructure. It is critical to understand the physical mechanisms of the compaction process in order to identify powder properties and optimal process parameters for achieving desired properties of the final product. Tools that can simulate particle rearrangement and deformation during the compaction process are usually developed to guide such fundamental understanding. This study aims at understanding powder compaction using particle mechanics approach. Specifically, it employs the nonlocal contact formulation to predict the contact behavior of a …


Modelling Catalytic Structures With Python And Ase, Tommie L. Day, Peilin Liao, Pilsun Yoo Aug 2017

Modelling Catalytic Structures With Python And Ase, Tommie L. Day, Peilin Liao, Pilsun Yoo

The Summer Undergraduate Research Fellowship (SURF) Symposium

Voltaic cells hold great potential as a source of clean electricity generation. These fuel sources are more efficient than combustion engines, and they do not produce environmentally harmful by-products. The electrochemical reaction which occurs within the cell is typically catalyzed by platinum, which increases the cost. The search for a better performing, less expensive catalyst is hindered by the lack of a complete, predictive theory of catalysis. Using Quantum Espresso and the Atomic Simulation Environment library for Python, we created a tool for nanoHUB.org which can visually and computationally model catalytic surfaces. This tool can simulate nanoparticles and metallic surfaces …


Improving Methods Of Doping On Black Phosphorus, Yuqin Duan, Adam Charnas, Jingkai Qin, Peide Ye Aug 2017

Improving Methods Of Doping On Black Phosphorus, Yuqin Duan, Adam Charnas, Jingkai Qin, Peide Ye

The Summer Undergraduate Research Fellowship (SURF) Symposium

Black phosphorus (BP) is a 2D semiconducting material with high carrier mobility. It is usually p-type due to oxidation states near its valence band. Although achieved through other growth methods, n-type doping has not yet been accomplished through the modern chemical vapor transport (CVT) growth method. To address this issue, small amounts of tellurium were added to Red Phosphorus to act as a dopant during the CVT growth process in addition to tin(Sn) and tin(IV) iodide, which facilitate growth. The chemicals are heated up to 600°C and precisely cooled in a 21-hour process, during which BP crystals should form. After …


Investigating Tantalum As A Plasma-Facing Component For Nuclear Fusion Reactors, Arvind Sundaram, Jitendra K. Tripathi, Theodore J. Novakowski, Ahmed Hassanein Ph. D. Aug 2017

Investigating Tantalum As A Plasma-Facing Component For Nuclear Fusion Reactors, Arvind Sundaram, Jitendra K. Tripathi, Theodore J. Novakowski, Ahmed Hassanein Ph. D.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Nuclear fusion is a potential source for producing unlimited environment-friendly energy. Tungsten (W) is selected as the primary candidate material for plasma facing component in nuclear fusion reactors due to its high melting temperature (3695 K), low sputtering erosion yield and strong mechanical properties. However, recent investigations on W have confirmed that it undergoes severe surface morphology changes during low energy He plasma and/or ion irradiation similar to a harsh fusion environment. Additionally, our previous studies indicate that tantalum (Ta) may show better resistance to the harsh radiation environment and is therefore worthy of investigation. Hydrogen retention properties, specifically deuterium …


Effect Of Particle Interactions On Powder Flow Behavior, Ivana A. Penagos, Carolina P. Mora, Teresa Carvajal Aug 2017

Effect Of Particle Interactions On Powder Flow Behavior, Ivana A. Penagos, Carolina P. Mora, Teresa Carvajal

The Summer Undergraduate Research Fellowship (SURF) Symposium

The study of powder flow behavior is essential for the development of processing technologies in many industries. In fact, powders have a major function in diverse types of manufacturing, such as pharmaceuticals, foods, chemicals, materials, minerals and cosmetics. This leads to an increasing demand for the development of reliable methods to assess powder flow problems in industry. This research intends to provide a general insight into how surface interactions and particle properties may alter powder flowability. The materials used for this study were lactose, starch, milk powder, cocoa and chocolate. These vary in their interparticle forces as well as on …


Atomistic Simulations Of Novel Nanoscale Semiconductor Devices: Resistance Switches And Two-Dimensional Transistors, Joseph P. Anderson, Mahbubul Islam, David Guzman, Alejandro Strachan Aug 2017

Atomistic Simulations Of Novel Nanoscale Semiconductor Devices: Resistance Switches And Two-Dimensional Transistors, Joseph P. Anderson, Mahbubul Islam, David Guzman, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

As transistors get smaller, we are achieving record levels of memory density. However, there is a limit to how small transistors can be made before their functionality breaks down. Thus alternatives to traditional transistor technology are needed. The two such technologies we examined are: resistance switching devices, which reversibly grow metal filaments through a dielectric, and two-dimensional transistors, which are capable of breaking through the scalability limit of traditional transistors. In order to design resistance switching devices which create filaments with some level of consistency, the dynamics of the filament formation need to be explored. Herein we model this process …


Cylindrical Shell Based Phase Transforming Cellular Materials: Designing A Recoverable Energy Dissipating Material, Gordon F. Jarrold, David Restrepo, Nilesh Mankame, Pablo Zavattieri Aug 2017

Cylindrical Shell Based Phase Transforming Cellular Materials: Designing A Recoverable Energy Dissipating Material, Gordon F. Jarrold, David Restrepo, Nilesh Mankame, Pablo Zavattieri

The Summer Undergraduate Research Fellowship (SURF) Symposium

Energy dissipating materials are used in a variety of impact events to protect more important parts of a system; one example of this is a football player’s helmet protecting a brain. A major drawback to classic energy dissipating materials however is that they dissipate energy through plastic deformation, meaning that after a single use, permanent deformations will prevent the material from being reusable to the same capacity as initially. We have designed a 1D cellular material in which geometric phase transformations in cylindrical shell elements are the primary energy dissipating mechanism, allowing for recoverability after use while keeping high energy …


Simulating Dynamic Failure Of Polymer-Bonded Explosives Under Periodic Excitation, Rachel Kohler, Camilo Duarte Cordon, Marisol Koslowski Aug 2017

Simulating Dynamic Failure Of Polymer-Bonded Explosives Under Periodic Excitation, Rachel Kohler, Camilo Duarte Cordon, Marisol Koslowski

The Summer Undergraduate Research Fellowship (SURF) Symposium

Accidental mishandling of explosive materials leads to thousands of injuries in the US every year. Understanding the mechanisms behind the detonation process is crucial to prevent such accidents. In polymer-bonded explosives (PBX), high-frequency mechanical excitation generates thermal energy and can lead to an increase in temperature and vapor pressure, and potentially the initiation of the detonation process. However, the mechanisms behind this energy release, such as the effects of dynamic fracture and friction, are not well understood. Experimental data is difficult to collect due to the different time scales of reactions and vibrations, so research is aided by running simulations …


Core-Shell Copper And Nickel Nanofoam: Uniform Electroplating And Properties, Hassan Zbib, David Bahr Aug 2017

Core-Shell Copper And Nickel Nanofoam: Uniform Electroplating And Properties, Hassan Zbib, David Bahr

The Summer Undergraduate Research Fellowship (SURF) Symposium

Characterizing materials on the nanoscale is a key factor to enhance nanotechnology in diverse applications, ranging from electronics to energy fields. However, controlling the structure of the material at the nanoscale or mimicking the nanoscale features of a structure that already exists requires linking processing conditions to the nanostructure. This work focuses on solids that show porous patterns at the nano-micro scale; these are often called cellular solids and classified into two categories: honeycombs and foams. This study focuses on nanofoams; with ligament dimensions in the sub-micron scale. Electrospinning has been developed to produce nanofoam structures of polymers with controlled …


Structure-Force Field Generator For Molecular Dynamics Simulations, Carlos M. Patiño, Lorena Alzate, Alejandro Strachan Aug 2017

Structure-Force Field Generator For Molecular Dynamics Simulations, Carlos M. Patiño, Lorena Alzate, Alejandro Strachan

The Summer Undergraduate Research Fellowship (SURF) Symposium

Atomistic and molecular simulations have become an important research field due to the progress made in computer performance and the necessity of new and improved materials. Despite this, first principle simulations of large molecules are still not possible because the high computational time and resources required. Other methods, such as molecular dynamics, allow the simplification of calculations by defining energy terms to describe multiple atom interactions without compromising accuracy significantly. A group of these energy terms is called a force field, and each force field has its own descriptions and parameters. The objective of this project was to develop a …


Study Of Persistent Slip Bands Formed By Low Cycle Fatigue On Nickel-Based Superalloys At Room Temperature, Anjola Uprety, Sae Matsunaga, Michael S. Titus Dr., Michael D. Sangid Dr., Alberto W. Mello Dr. Aug 2017

Study Of Persistent Slip Bands Formed By Low Cycle Fatigue On Nickel-Based Superalloys At Room Temperature, Anjola Uprety, Sae Matsunaga, Michael S. Titus Dr., Michael D. Sangid Dr., Alberto W. Mello Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

The ability of Ni-based superalloys to withstand temperatures in excess of 11000C makes them useful for applications in the hottest components in jet engines, gas turbines, and thrust engines. Increasing the efficiency of these gas turbine engines helps to reduce the fossil fuel consumption and the production of greenhouse gasses. A common mode of failure in these Ni-based superalloys is low cycle fatigue, in which narrow regions of high dislocation density, which are known as persistent slip bands (PSBs), can develop and lead to crack initiation. A detailed understanding of the formation and structure of PSBs has eluded …


Characterization Of Superabsorbent Polymers In Aluminum Solutions, Nicholas D. Macke, Matthew J. Krafcik, Kendra A. Erk Aug 2016

Characterization Of Superabsorbent Polymers In Aluminum Solutions, Nicholas D. Macke, Matthew J. Krafcik, Kendra A. Erk

The Summer Undergraduate Research Fellowship (SURF) Symposium

Over the past few decades, super absorbent polymers (SAPs) have been the topic of research projects all around the world due to their incredible ability to absorb water. They have applications in everything from disposable diapers to high performance concrete. In concrete, aqueous cations permeate the polymer network, reducing swelling and altering properties. One of these ions, aluminum, alters SAP properties by creating a stiff outer shell and greatly reducing absorbency, but these effects have not been well characterized. One method of characterizing the effects of aluminum on SAP hydrogels was performing gravimetric swelling tests to determine equilibrium water capacity …


Large Scale Monolithic Solar Panel Simulation - A Study On Partial Shading Degradation, Suhas V. Baddela, Xingshu Sun, Muhammad A. Alam Aug 2016

Large Scale Monolithic Solar Panel Simulation - A Study On Partial Shading Degradation, Suhas V. Baddela, Xingshu Sun, Muhammad A. Alam

The Summer Undergraduate Research Fellowship (SURF) Symposium

Shadow-induced degradation is a major concern for both power output and long-term reliability in solar cells. Apart from the obvious fact that shading reduces the amount of solar irradiance available to solar panels, it may lead to formation of hot spots, where solar cells are forced to reverse breakdown with localized heating, and potentially, permanent damage. To get a better understanding of shadow-induced degradation, we develop an electro-thermal coupled simulator that can self-consistently solve the electrical and thermal distributions of solar panel under arbitrary shading conditions. The simulation framework consists of two part: a) compact models that can describe the …


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 …