Materials Science and Engineering Commons^™

Stanford Stratified Structure Solver (S4) Simulation Tool, Chang Liu, Xufeng Wang, Peter Bermel

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Stanford Stratified Structure Solver (S4) developed in 2012 allows for fast, accurate prediction of optical propagation through complex 3D structures. However, there have been two key challenges preventing wider use to date: the use of a specialized control language, and the difficulty of incorporating realistic materials parameters. In this project, both concerns have been addressed. We have constructed a graphical user interface as an alternative, using the open-source Rappture platform on nanoHUB. This has been combined with a comprehensive materials database known as PhotonicsDB, which incorporates materials optical data drawn from carefully vetted sources. An Octave script file was …

Assessing The Mvs Model For Nanotransistors, Siyang Liu, Xingshu Sun, Mark S. Lundstrom

The Summer Undergraduate Research Fellowship (SURF) Symposium

A simple semi-empirical compact MOSFET model has been developed, which is called MIT virtual source (MVS) model. Compare to other model used in industry, MVS model requires only a few parameters, most of which can be directly obtained from experiment, and produce accurate results. One aim of this paper is to test the applicability of the MVS model to transistor made from MoS₂ rather than silicon. Another target is to determine the sustainability of the MVS model under different transistor tests. To achieve these goals, the MVS model will be used to fit the experimental data on MoS_{2 …}

Compression Testing And Failure Modes Of Steel-Concrete Composite (Sc) Structures For Nuclear Containment, Patrick Michael Wanamaker, Amit H. Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

Although being able to provide much cleaner power than burning coal and other fossil fuels, nuclear power plants are still a tough sell to the general public due to their history of being spontaneously dangerous. The containment structures surrounding these nuclear plants, however, can play a huge role in reducing the risks associated with them. Relatively new designs for these containment assemblies, known as SC (steel-concrete composite) structures, aim to increase the strength and durability of the containment facilities while keeping costs down. By varying the spacing between shear studs, the ratio of concrete to steel, and the ratio of …

Validation Of Long-Fiber Thermoplastic Composite Models, Christian A. Vuong, Megan Kinney, Michael Sangid

The Summer Undergraduate Research Fellowship (SURF) Symposium

With increased pressure to reduce energy consumption, long-fiber reinforced thermoplastic composites (LFTs) are of interest to aerospace and automotive industries due to their light weight in combination with other desirable mechanical properties and ease of manufacturing to replace common materials such as aluminum and magnesium. However, the performance of LFTs is highly dependent on microstructural variables such as fiber length and orientation, which are heavily influenced by the manufacturing process. Accurately predicting these factors would allow for more rapid advances in LFTs by reducing the experiments needed for certification and decreasing expenses. While models that serve this purpose exist, the …

Pulsed Laser Coating Of Bioceramic (Hap) And Niti Nanoparticles On Metallic Implants, Aayush Goswami, Gary J. Cheng

The Summer Undergraduate Research Fellowship (SURF) Symposium

This research deals with increasing the biocompatibility of the bio implants which have a global market valued more than $94.1 billion . The surface of the metal alloys used for the bone implants need to be coated with bio compatible materials like HAp(Hydroxyapatite), graphene, etc. in order to promote the growth of cells(osteoblasts) on the surface of the implants. Various techniques like plasma spray coating, ion beam sputter coating, etc. have been used before to coat such materials on a substrate, however these have faced problems of coating quality. In order to perfect this coating, that is make it more …

Computation Of Piezo-Electric Materials, Seung Yun Song, R. Edwin García

The Summer Undergraduate Research Fellowship (SURF) Symposium

Piezo -electric materials are materials that will change its shape and size when an electric field is applied to the material. Vice versa, these materials will generate a certain voltage when they are bent, vibrated, or deformed. These materials show promising future , because they link mechanical and electrical properties of a material. In 21^st century when electronic devices such as smart phones or touch-screen TV’s depend highly on mechanical input such as human’s touch, developing and researching materials that can link the mechanical and electrical properties can greatly improve the quality of i-phones. The main challenge regarding piezo-electric …

Insights Into The Effect Of Geometrical Parameters In The Mechanical Properties Of The Radular Teeth Of The Cryptochiton Stelleri – A 3d Print Approach, Chan Jeong, Enrique Escobar, Pablo Zavattieri Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Cryptochiton Stelleri is known to have ultra-hard radular teeth that have one of the largest hardness (9-12GPa) and stiffness (90-125GPa) among other biological materials such as Enamel and Abalone shell. The ultrastructure of the teeth is formed by a bundle of highly mineralized rods composed of iron oxides and organic material. The main method to measure the material properties has been through nanoindentation. However there are limitations to nanoindentation of the Chiton’s teeth such as limited equipment, costly and time consuming preparation of the samples, and observation of nanoscale features being difficult. In this work, the rod-like microstructure of …

Iron-Magnesium Alloy Bioabsorbable Blood Stent, Kaitlyn Jarry, L Stanciu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bioabsorbable materials are fairly new and proper alloys for implantation in the body have not yet been established. There are a few polymers that have showed promise, but they do not provide the proper mechanical support that metal does. These materials would be used to create devices such as blood stents and orthopedic screws. Investigation into the properties of different alloys can help to establish a material that can be used for implanted devices that are only needed for a limited amount of time. In order to investigate these alloys many different experiments will to be run to test the …

Python-Based Simulation Tool For Kinetic Monte Carlo, Zaiwei Zhang, R. Edwin García

The Summer Undergraduate Research Fellowship (SURF) Symposium

Simulation tools are highly needed for testing or designing nanotechnology in university research projects.The problem in the current simulation tool used in our research, which is conducted by Prof.Garcia in MSE department at Purdue, is that users cannot observe the changing numbers of diffusivities during Vacancy Diffusion simulations between different materials. Also, there is no Graphic User Interface for the simulation tools.To solve the problem, the Virtual Kinetics of Materials Laboratory program is used to create the Graphic User Interface. Also, GTK+ toolkit has been used to create a pop-up window displaying updated diffusivities during the simulation. For user purpose, …

Electrochemical Sensing With Metal Oxides, Isabella Ramirez, Lia Stanciu, Alexandra Snyder

The Summer Undergraduate Research Fellowship (SURF) Symposium

The effective sensing of hydrogen peroxide is important for a variety of reasons. It can be utilized as a diagnostic tool for diseases like asthma; also, the sensing can be utilized in pharmaceutical and food production for quality control. The use of silver oxide nanoparticles with varying morphologies has not been investigated as a sensing agent for hydrogen peroxide in the past. The particles’ properties and ability to oxidize and reduce hydrogen peroxide suggest that they will be effective to create a sensitive sensor. The silver oxide particles were prepared through chemical reduction using varying molar ratios of reactants. The …

Use Of Oscillatory Shear To Study The Effect Of Limestone Filler On The Rheology Of Early-Age Portland Cement, Christopher W. Barney, Kendra Erk

The Summer Undergraduate Research Fellowship (SURF) Symposium

Cement is a material that has been in use since the ancient times and is the most widely manufactured material in industry today. During the production of cement, limestone undergoes a process called calcination which releases CO₂. In order to reduce the environmental impact and cost of cement production it has become standard practice to replace a portion of the cement mixture with ground limestone, but this causes a change in the rheological profile of the mixture. This change in rheology affects both the short and long term workability of the material. In this study, small amplitude oscillatory …

In Situ Study Of The Role Of Substrate Temperature During Atomic Layer Deposition Of Hfo2 On Inp, H. Dong, Santosh Kc, X. Qin, B. Brennan, S. Mcdonnell, D. Zhernokletov, C. Hinkle, J. Kim, K. Cho, R. Wallace

Faculty Publications

The dependence of the “self cleaning” effect of the substrate oxides on substrate temperature during atomic layer deposition (ALD) of HfO2 on various chemically treated and native oxide InP (100) substrates is investigated using in situ X-ray photoelectron spectroscopy. The removal of In-oxide is found to be more efficient at higher ALD temperatures. The P oxidation states on native oxide and acid etched samples are seen to change, with the total P-oxide concentration remaining constant, after 10 cycles of ALD HfO2 at different temperatures. An (NH4)2 S treatment is seen to effectively remove native oxides and passivate the InP surfaces …

High Field Breakdown Characteristics Of Carbon Nanotube Thin Film Transistors, Man Prakash Gupta, Ashkan Behnam, Feifei Lian, David Estrada, Eric Pop, Satish Kumar

Materials Science and Engineering Faculty Publications and Presentations

The high field properties of carbon nanotube (CNT) network thin film transistors (CN-TFTs) are important for their practical operation, and for understanding their reliability. Using a combination of experimental and computational techniques we show how the channel geometry (length L_C and width W_C) and network morphology (average CNT length L_t and alignment angle distribution θ) affect heat dissipation and high field breakdown in such devices. The results suggest that when W_C ≥ L_t, the breakdown voltage remains independent of W_C but varies linearly with L_C. The breakdown power varies …

Analyzing Hexavalent Chromium (Cr Vi)-Free Paint Systems For Sls, Maria Emma Torres

Von Braun Symposium Student Posters

No abstract provided.

Zno Nanoneedle/H2o Solid-Liquid Heterojunction-Based Self-Powered Ultraviolet Detector, Qinghao Li, Lin Wei, Yanru Xie, Kai Zhang, Lei Liu, Dapeng Zhu, Jun Jiao, Yanxue Chen, Shishen Yan, Guolei Liu, Liangmo Mei

Physics Faculty Publications and Presentations

ZnO nanoneedle arrays were grown vertically on a fluorine-doped tin oxide-coated glass by hydrothermal method at a relatively low temperature. A self-powered photoelectrochemical cell-type UV detector was fabricated using the ZnO nanoneedles as the active photoanode and H2O as the electrolyte. This solid-liquid heterojunction offers an enlarged ZnO/water contact area and a direct pathway for electron transport simultaneously. By connecting this UV photodetector to an ammeter, the intensity of UV light can be quantified using the output short-circuit photocurrent without a power source. High photosensitivity, excellent spectral selectivity, and fast photoresponse at zero bias are observed in this UV detector. …

A Tensile Deformation Model For In-Situ Dendrite/Metallic Glass Matrix Composites, J. W. Qiao, T. Zhang, Fuqian Yang, P. K. Liaw, S. Pauly, B. S. Xu

Chemical and Materials Engineering Faculty Publications

In-situ dendrite/metallic glass matrix composites (MGMCs) with a composition of Ti₄₆Zr₂₀V₁₂Cu₅Be₁₇ exhibit ultimate tensile strength of 1510 MPa and fracture strain of about 7.6%. A tensile deformation model is established, based on the five-stage classification: (1) elastic-elastic, (2) elastic-plastic, (3) plastic-plastic (yield platform), (4) plastic-plastic (work hardening), and (5) plastic-plastic (softening) stages, analogous to the tensile behavior of common carbon steels. The constitutive relations strongly elucidate the tensile deformation mechanism. In parallel, the simulation results by a finite-element method (FEM) are in good agreement with the experimental findings and theoretical calculations. The present study gives a mathematical model to clarify …

Modeling The Atomic And Electronic Structure Of Metal-Metal, Metal-Semiconductor And Semiconductor-Oxide Interfaces, Ganesh Krishna Hegde

Open Access Dissertations

The continuous downward scaling of electronic devices has renewed attention on the importance of the role of material interfaces in the functioning of key components in electronic technology in recent times. It has also brought into focus the utility of

atomistic modeling in providing insights from a materials design perspective. In this thesis, a combination of Semi Empirical Tight-Binding (TB), first-principles Density

Functional Theory and Reactive Molecular Dynamics (MD) modeling is used to study aspects of the electronic and atomic structure of three such 'canonical' material interfaces - Metal-Metal, Metal-Semiconductor and Semiconductor oxide interfaces.

An important contribution of this thesis …

Soil Nutrient Availability Properties Of Biochar, Nicole C. Esposito

Master's Theses

Biochar’s high porosity and negative surface charge allows for numerous soil and plant benefits such as increased water retention, high nutrient availability, and plant growth. By analysing biochar’s effect of all of these factors, a system can be put in place in which soils can be remediated with the proper soil amendments. This report discusses and tests the effects of varying rates of biochar on pH levels, cation exchange capacity, and nutrient exchangeability (of calcium, magnesium, sodium, and potassium) in soil. Corn plants were also grown in soils of varying amendment types and analysed for plant growth and germination to …

Spectroscopic And Kinetic Characterization Of Catalytic Materials For The Conversion Of Biomass-Derived Compounds, Paul James Dietrich

Open Access Dissertations

As economies look to transition away from petroleum for social, economic, and political reasons, biomass will continue to attract attention as a renewable feedstock for the fuels and chemicals industry. In order to turn biomass into end use fuels and chemicals, the oxygen content must be lowered significantly, requiring large hydrogen inputs. For these processes to be completely renewable, the hydrogen must come from biomass or biomass-derived compounds. In this work, catalysts for the aqueous phase reforming (APR) of biomass-derived sugars were characterized by a combination of reaction kinetics, X-ray spectroscopy, electron microscopy, and theoretical computation to determine the active …

The Comparison Of Composite Aircraft Field Repair Method (Cafrm) With Traditional Aircraft Repair Technologies, Peng Hao Wang

Open Access Dissertations

In the aviation industry, manufacturers made the transition from aluminum to composite materials for the majority of their primary structures over the last few decades. While the design and manufacturing techniques have consistently evolved, field repair methods were consistently overlooked. In this study, specimens fabricated using some of the common repair methods such as the autoclave repair method, and Double Vacuum Debulk (DVD) repair method were tested against the Composite Aircraft Field Repair Method (CAFRM) proposed by the researcher. Specimens were tested with microscopy, acid digestion, short beam shear, and mode I fracture tests. The researcher was able to determine …