Engineering Commons^™

High Switching Endurance In TaoX Memristive Devices, Jianhua Yang, M Zhang, John Strachan, Feng Miao, Matthew Pickett, Ronald Kelley

Electrical and Computer Engineering Faculty Publication Series

We demonstrate over 1×1010 open-loop switching cycles from a simple memristive device stack of Pt/TaO��/Ta. We compare this system to a similar device stack based on titanium oxides to obtain insight into the solid-state thermodynamic and kinetic factors that influence endurance in metal-oxide memristors.

Tunable Band Gaps In Bilayer Graphene-Bn Heterostructures, Ashwin Ramasubramaniam, Doron Naveh, Elias Towe

Mechanical and Industrial Engineering Faculty Publication Series

We investigate band-gap tuning of bilayer graphene between hexagonal boron nitride sheets, by external electric fields. Using density functional theory, we show that the gap is continuously tunable from 0 to 0.2 eV, and is robust to stacking disorder. Moreover, boron nitride sheets do not alter the fundamental response from that of free-standing bilayer graphene, apart from additional screening. The calculations suggest that the graphene-boron nitride heterostructures could provide a viable route to graphene-based electronic devices.

High-Strength Wastewater Treatment By Microalgae, Xin Yuan

Environmental & Water Resources Engineering Masters Projects

Microalgae spontaneously convert CO2 and supplementary nutrients into biomass in the presence of light via photosynthesis, and at much higher rates than convention oil-producing crops. Algal biomass can then be transformed into methane via anaerobic bacteria-mediated fermentation, or to biodiesel via lipid extraction, as well as other byproducts of secondary metabolism. Production of biofuel by microalgae can be made more sustainable through coupling microalgal biomass production with existing power generation and wastewater treatment infrastructure. On the other hand, integration of algal biofuel production into wastewater treatment plant anaerobic digestion infrastructure has the potential to increase biogas production, decrease high and …

Two-Stage Filtration To Control Manganse And Dbps At The Lantern Hill Water Treatment Plant, Minh Pham

Environmental & Water Resources Engineering Masters Projects

This research involved full- and pilot-scale studies of treatment of the Aquarion Water Company (AWC) Lantern Hill groundwater source. With elevated levels of both dissolved manganese (~0.19 mg/L), dissolved iron (~1.9 mg/L) and natural organic matter (NOM) (~3 mg/L) the existing treatment plant is having difficulty in achieving required manganese removal while maintaining low concentrations of disinfection byproducts (DBPs) in finished water. At full-scale, dissolved manganese in the raw water is removed through pre-filter oxidation and adsorption on iron precipitates via application of free chlorine and permanganate as well as adsorption of dissolved manganese onto MnOx(s) coated filter media (anthracite …

Diffusion Of Adhesion Layer Metals Controls Nanoscale Memristive Switching, Jianhua Yang, John Strachan, Qiangfei Xia, Douglas Ohlberg, Philip Kuekes, Ronald Kelley, William Stickle, Duncan Stewart, Gilberto Medeiros-Ribeiro,, R Stanley Williams

Electrical and Computer Engineering Faculty Publication Series

Thermal diffusion of Ti through Pt electrode forms Ti atom channels of 1 nm diameter along Pt grain boundaries, seeding switching centers and controlling nanoscale memristive switching. The image shows EFTEM maps of Ti overlaid on HRTEM images for a Si/SiO2 100 nm/Ti 5nm/Pt 15 nm sample in-situ annealed in ultrahigh vacuum at 250 °C for 1 hour.

Regenerating Spent Zeolites With Uv And Uv/H2o2 To Enhance Removal Of Endocrine Disrupting Compounds, Safina Singh

Environmental & Water Resources Engineering Masters Projects

Endocrine disrupting compounds (EDCs) have become contaminants of emerging concern due to their potential for harmful effects on human and ecological health, at low concentrations (ppb). As an alternative to conventional adsorption media, activate carbon, this study investigates feasibility of using high-silica, hydrophobic zeolites for the removal of EDCs through adsorption process. Zeolites are crystalline, porous alumino-silicate with well defined pore structures, and tetrahedral framework.

While traditional media regeneration processes are energy and cost intensive, evidence has been found that zeolites can be regenerated multiple times through relatively inexpensive methods using direct ultraviolet (UV) photolysis and advanced oxidation process (AOP). …

Western Woburn Greenway Study, Jennifer H. Masters, Bryan C. Aldeghi, Eric C. Kells, Maureen C. Pollock, Rebekah Lynne Decourcey, Carol Waag, Youjin Kwon, Kathryn E. Ostermier, Patrick T. Mcgeough, Ryan Patrick Ball

Landscape Architecture & Regional Planning Studio and Student Research and Creative Activity

In spring 2010, the Department of Landscape Architecture and Regional Planning at the University of Massachusetts Amherst was asked to complete a landscape planning study, the “Western Woburn Greenway Study” for the City of Woburn, MA. The study was undertaken by a team of graduate students, supervised by Professor Jack Ahern. The goals of that study are as follows.

The City of Woburn currently has two large parcel groups of undeveloped land, Whispering Hill (the north focus area) and Winning/Shannon Farms (the south focus area) that are, or may become, available for acquisition (see “Scope of Project” below). The first …

Expanding Ethics Education In Science & Engineering, Jane E. Fountain

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …

Nsf Supported Case-Studies Done By Systems Engineering Graduate Students At Uva, Michael Gorman

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …

Science And Engineering Ethics Education: Recipes For Success, Philip J. Langlais

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …

Rcr For Postdocs: Promoting Ethical Professional Development, Kathleen Flint

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …

Update On Responsible Conduct Of Research, Michael E. Gorman, Kelly Joyce

Ethics in Science and Engineering National Clearinghouse

This presentation was part of the AAAS Annual Conference professional development workshop, National Science Foundation and Ethics Education in Science and Engineering, during the recent meeting in San Diego, California (18-22 February). Dr. Michael Gorman, Program Director, Science, Technology & Society, National Science Foundation, moderated the workshop presentations and the discussion that followed. In addition, he contributed a set of powerpoint slides outlining the role of NSF in its response to the America Competes Act, including a commitment to support an online resource in ethics education. Dr. Philip Langlais, Vice Provost for Graduate Studies & Research, Old Dominion University, presented …

My Italian Connections: Otto Vogl In Italy, Otto Vogl, Gerald S. Kirshenbaum

Emeritus Faculty Author Gallery

This document describes Otto Vogl's work in Italy. From 1975, Vogl served for 3 years as the Chairman of the Scientific Advisory Committee to the President Italo Trapasso of the Plastic Materials Company of Montedison SA, Milan, Italy. He was assigned to restructure the research activities and to organize the Research Division. He was responsible for the appointment of DiDrusco as the Vice President of Research and Paolo Galli as the Director of Research at the company’s facilities in Ferrara. Within a year of Vogl’s reorganization of the research organization the high yield catalyst for the polymerization of propylene was …

Anhang: Auszüge Aus Dem Späteren Leben Von Professor Dr. Otto Vogl, Otto Vogl

Emeritus Faculty Author Gallery

No abstract provided.

Post Silicon Clock Tuning System To Mitigate The Impact Of Process Variation On Performance, Kelageri Nagaraj

Masters Theses 1911 - February 2014

Optical shrink for process migration, manufacturing process variation and dynamic voltage control leads to clock skew as well as path delay variation in a manufactured chip. Since such variations are difficult to predict in pre-silicon phase, tunable clock buffers have been used in several microprocessor designs. The buffer delays are tuned to improve maximum operating clock frequency of a design. This however shifts the burden of finding tuning settings for individual clock buffers to the test process. In this project, we describe a process of using tester measurements to determine the settings of the tunable buffers for recovery of performance …

Approaches To Multiprocessor Error Recovery Using An On-Chip Interconnect Subsystem, Ramakrishna P. Vadlamani

Masters Theses 1911 - February 2014

For future multicores, a dedicated interconnect subsystem for on-chip monitors was found to be highly beneficial in terms of scalability, performance and area. In this thesis, such a monitor network (MNoC) is used for multicores to support selective error identification and recovery and maintain target chip reliability in the context of dynamic voltage and frequency scaling (DVFS). A selective shared memory multiprocessor recovery is performed using MNoC in which, when an error is detected, only the group of processors sharing an application with the affected processors are recovered. Although the use of DVFS in contemporary multicores provides significant protection from …

Evaluation Of An Eye Tracking Device To Increase Error Recovery By Nursing Students Using Human Patient Simulation, Yan Shen

Masters Theses 1911 - February 2014

This study evaluates the application of an eye tracking device in nursing education. An experiment is designed to test the effectiveness of the eye tracking device used as a tool for providing instructional feedback in error identification and recovery by nursing students undertaking tasks in a simulated clinical setting. This experiment is performed on three groups of nursing students. In the first phase, all groups are tested in a simulated clinical scenario and their eye movements are recorded using an eye tracking device. In the second phase, the evaluation only group (control group) gets instructors’ feedback regarding their performance without …

Calibration Of The Umass Advanced Multi-Frequency Radar, Matthew Mclinden

Masters Theses 1911 - February 2014

The Advanced Multi-Frequency Radar is a three-frequency system designed and built by the University of Massachusetts Microwave Remote Sensing Lab (MIRSL). The radar has three frequencies, Ku-band (13.4 GHz), Ka-band (35.6 GHz), and W-band (94.92GHz). The additional information gained from additional frequencies allows the system to be sensitive to a wide range of atmospheric and precipitation particle sizes, while increasing the ability to derive particle microphysics from radar retrievals.

This thesis details the calibration of data from the Canadian CloudSat/CALIPSO Validation Project (C3VP) held during January 2007 in Ontario, Canada. The calibration used internal calibration path data and was confirmed …

Evaluating A New Mac For Current And Next Generation Rfid, Serge Zhilyaev

Masters Theses 1911 - February 2014

We evaluate SQUASH, a new MAC for RFID, in hardware and software. A smaller hardware design for SQUASH is proposed which also reduces latency. Area and latency in hardware are reduced further with a new variant we call permuted SQUASH. We explore SQUASH on embedded microprocessors and propose a method to choose the optimal partial product ordering to reduce latency.

Sorption Of Bovine Serum Albumin On Nano And Bulk Oxide Particles, Lei Song

Masters Theses 1911 - February 2014

Manufactured oxide nanoparticles (NPs) have large production and widespread applications, which will inevitably enter the environment. NPs can interact with proteins in living beings due to the fact that NPs can transport into blood or across cell membranes into cells. Conformational change of protein molecules after sorption on oxide NPs has been reported. Therefore, it is important to understand the adsorption mechanism of protein onto oxide NPs surfaces. Although few works have reported protein adsorption behaviors, a general systematic comparison of the effects of particle size and surface groups on protein adsorption by widely studied NPs still needs to be …

Route Choice Behavior In Risky Networks With Real-Time Information, Michael D. Razo

Masters Theses 1911 - February 2014

This research investigates route choice behavior in networks with risky travel times and real-time information. A stated preference survey is conducted in which subjects use a PC-based interactive maps to choose routes link-by-link in various scenarios. The scenarios include two types of maps: the first presenting a choice between one stochastic route and one deterministic route, and the second with real-time information and an available detour. The first type measures the basic risk attitude of the subject. The second type allows for strategic planning, and measures the effect of this opportunity on subjects' choice behavior.

Results from each subject are …

A Quantitative Analysis Of The Impacts From Selected Variables Upon Safety Belt Usage In Massachusetts, Samuel W. Gregorio

Masters Theses 1911 - February 2014

Safety belts are the most effective safety device in vehicles in terms of preventing injuries (1). Every year, safety belt usage data across the nation is collected by the individual states, the District of Columbia, and U.S. territories in a probability-based observational survey. Using this survey, Massachusetts, a secondary seat belt law state, ranked last in safety belt usage in 2008. This percentage was approximately a 2 percent decrease from 2007. This value was not an aberration as within the recent past, Massachusetts, a secondary safety belt law state, has consistently ranked at or near the bottom of the 50 …

Scalable, Memory-Intensive Scientific Computing On Field Programmable Gate Arrays, Salma Mirza

Masters Theses 1911 - February 2014

Cache-based, general purpose CPUs perform at a small fraction of their maximum floating point performance when executing memory-intensive simulations, such as those required for many scientific computing problems. This is due to the memory bottleneck that is encountered with large arrays that must be stored in dynamic RAM. A system of FPGAs, with a large enough memory bandwidth, and clocked at only hundreds of MHz can outperform a CPU clocked at GHz in terms of floating point performance. An FPGA core designed for a target performance that does not unnecessarily exceed the memory imposed bottleneck can then be distributed, along …

Fast Parameter-Space Sweep Of Wideband Electromagnetic Systems Using Bt-Pod, Wei Wang

Masters Theses 1911 - February 2014

Modeling and design of high frequency electronic systems such as antennas and microwave devices require the rigorous numerical solution of Maxwell’s equa- tions. The frequency-domain (time-harmonic) tangential vector finite element method (TVFEM) for Maxwell equations results in a second-order dynamical electromagnetic model that must be repeatedly solved for multiple frequencies, excitation or material parameters each design loop. This leads to extremely long design turnaround that often is not optimal. This work will propose an accurate, error controllable and ef- ficient multi-parametric model order reduction scheme that significantly accelerate these parameters sweep. At the core of this work is the proper …

Historic Bridge Evaluation Using Finite Element Techniques, Helena M. Charron

Masters Theses 1911 - February 2014

The present study examined the application of modern, computer-based analysis methods to two existing historic bridges in Massachusetts. The first bridge featured in this study is the Woronoco Bridge, a reinforced concrete open spandrel arch bridge that was constructed in 1923. It was hoped that a computer-based, parametric study of this bridge would prove it to be deck-stiffened, similar to select bridges of Swiss engineer Robert Maillart. However, the results do not support that there was any intent to reduce bending in the arch as a result of increasing the stiffness of the bridge deck. Instead, the Woronoco Bridge appears …

Optical Lithography Simulation Using Wavelet Transform, Rance Rodrigues

Masters Theses 1911 - February 2014

Optical lithography is an indispensible step in the process flow of Design for Manufacturability (DFM). Optical lithography simulation is a compute intensive task and simulation performance, or lack thereof can be a determining factor in time to market. Thus, the efficiency of lithography simulation is of paramount importance. Coherent decomposition is a popular simulation technique for aerial imaging simulation. In this thesis, we propose an approximate simulation technique based on the 2D wavelet transform and use a number of optimization methods to further improve polygon edge detection. Results show that the proposed method suffers from an average error of less …

Simulations Of Flow Over Wind Turbines, Dnyanesh A. Digraskar

Masters Theses 1911 - February 2014

One of the most abundant sources of renewable energy is wind. Today, a considerable amount of resources are being utilized for research on harnessing the wind energy efficiently. Out of all the factors responsible for efficient energy production, the aerodynamics of flow around the wind turbine blades play an important role. This work aims to undertake aerodynamic analysis of a Horizontal Axis Wind Turbine. A steady state, incompressible flow solver for multiple reference frames, MRFSimple- Foam is modified and used for performing simulations of flow over National Renewable Energy Laboratory Phase VI wind turbine rotor. The code is first tested …

Web-Dinar: Web Based Diagnosis Of Network And Application Resources In Disaster Response Systems, Kartik Deshpande

Masters Theses 1911 - February 2014

Disaster management and emergency response mechanisms are coming of age post 9/11. Paper based triaging and evacuation is slowly being replaced with much advanced mechanisms using remote clients (Laptops, Thin clients, PDAs), RFiDs etc. This reflects a modern trend to deploy Information Technology (IT) in disaster management. IT elements provide a great a deal of flexibility and seamlessness in the communication of information. The information flowing is so critical that, loss of data is not at all acceptable. Loss of data would mean loss of critical medical information portraying the disaster scenario. This would amount to a wrong picture being …

Efficient Modeling Techniques For Time-Dependent Quantum System With Applications To Carbon Nanotubes, Zuojing Chen

Masters Theses 1911 - February 2014

The famous Moore's law states: Since the invention of the integrated circuit, the number of transistors that can be placed on an integrated circuit has increased exponentially, doubling approximately every two years. As a result of the downscaling of the size of the transistor, quantum effects have become increasingly important while affecting significantly the device performances. Nowadays, at the nanometer scale, inter-atomic interactions and quantum mechanical properties need to be studied extensively. Device and material simulations are important to achieve these goals because they are flexible and less expensive than experiments. They are also important for designing and characterizing new …

Electronic Falls Reporting System Implementation: Evaluating Data Collection Methods And Studying User Acceptance, Yi You Mei

Masters Theses 1911 - February 2014

In this research, we detail the development of a novel, easy-to-use system to facilitate electronic patient falls reporting within a long-term residential care facility (LTRCF) using off-the-shelf technology that can be inexpensively implemented in a wide variety of settings. We report the results of four complimentary system evaluation measures that take into consideration varied organizational stakeholders’ perspectives: 1) System-level benefits and costs, 2) System usability, via scenario-based use cases, 3) A holistic assessment of users’ physical, cognitive, and marcoergonomic (work system) challenges in using the system, and 4) User technology acceptance. We report the viability of collecting and analyzing data …