Engineering Commons^™

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 …

Investigation Of The Behavior Of Open Cell Aluminum Foam, Patrick J. Veale

Masters Theses 1911 - February 2014

The study investigates the behavior open cell aluminum foam in scenarios applicable to potential use in structural applications. Behavior was examined through mechanical testing, computer modeling and analytic expressions. Existing assumptions about the foam characteristics that define the elastic properties were expanded to include contributions of axial and shear deformations in addition to bending and were rewritten in terms of the axial and bending stiffness ratios of ligaments. Compressive and tensile tests were performed to gain a measure of the elastic properties of the foam as well as the behavior and failure mechanisms in both loading conditions. The materials used …

Material Characterization And Structural Response Of Historic Truss Bridges, Sean L. Kelton

Masters Theses 1911 - February 2014

Historic truss bridges are examined in this thesis through material characterization of wrought iron and structural evaluation of an early 20th century pony truss bridge. The mechanical properties of wrought iron from six 19th century truss bridges were evaluated through mechanical testing that includes hardness and tension tests. The main findings of this work are: 1) That hardness is a poor predictor of yield and ultimate stress but has some ability in screening iron for iron with low ductility, 2) there is a statistically significant difference in the distribution of yield and ultimate stresses between material samples from different bridges, …

Investigation Of 3-D Heat Transfer Effects In Fenestration Products, Sneh Kumar

Masters Theses 1911 - February 2014

Buildings in USA consume close to 40% of overall energy used and fenestration products (e.g. windows, doors, glazed-wall etc.) are the largest components of energy loss from buildings. Accurate evaluation of thermal performances of fenestration systems is critical in predicting the overall building energy use, and improving the product performance. Typically, two-dimensional (2-D) heat transfer analysis is used to evaluate their thermal performance as the 3-D analysis is highly complex process requiring significantly more time, effort, and cost compared to 2-D analysis. Another method of evaluation e.g. physical test in a hotbox is not possible for each product as they …

Advanced Blade Testing Methods For Wind Turbines, Puneet Malhotra

Masters Theses 1911 - February 2014

This thesis consists of a detailed analysis of different blade testing methods and improvements to a novel concept for tri-axial testing of large wind turbine blades. As the blades are one of the most critical components of the wind turbine, they have to be tested in order to ensure that their specifications are consistent with the actual performance of the blade. It must be demonstrated that the blade can withstand both the ultimate loads and the fatigue loads to which the blade is expected to be subjected during its design service life. There are basically two types of blade testing: …

Route Choice Behavior In A Driving Simulator With Real-Time Information, Hengliang Tian

Masters Theses 1911 - February 2014

This research studies travelers' route choice behavior in a driving simulator with real-time information en-route. We investigate whether travelers plan strategically for real-time information en-route or simply select a fixed path from origin to destination at the beginning of a trip, and whether network complexity and a parallel driving task affect subjects' strategic thinking ability. In this study, strategic thinking refers to a traveler's route choice decision taking into account future diversion possibilities downstream enabled by information at the diversion node. All of the subjects in this study participated in driving-simulator-based tests while half of the subjects participated in additional …

Data Fusion For The Problem Of Protein Sidechain Assignment, Yang Lei

Masters Theses 1911 - February 2014

In this thesis, we study the problem of protein side chain assignment (SCA) given

multiple sources of experimental and modeling data. In particular, the mechanism

of X-ray crystallography (X-ray) is re-examined using Fourier analysis, and a novel

probabilistic model of X-ray is proposed for SCA's decision making. The relationship

between the measurements in X-ray and the desired structure is reformulated in terms

of Discrete Fourier Transform (DFT). The decision making is performed by developing

a new resolution-dependent electron density map (EDM) model and applying

Maximum Likelihood (ML) estimation, which simply reduces to the Least Squares

(LS) solution. Calculation of the …

Earthquake Engineering Simulation With Flexible Cladding System, Jun Jie Li

Masters Theses 1911 - February 2014

This research investigates the interaction between heavy precast cladding units attached to steel framed buildings. Cladding systems are designed as non-structural components and are not expected to contribute to the energy absorption of the primary structure. However, research has indicated that the cladding system may be designed to reduce the response of the primary structure under seismic excitations. The use of flexible connections between the cladding and primary structural frames may be able to provide beneficial effects to the entire structural response. In this study, a series of earthquake engineering simulations were conducted in OPENSEES to analyze the effects of …

The Impact Of Flexibility And Capacity Allocation On The Performance Of Primary Care Practices, Liang Wang

Masters Theses 1911 - February 2014

The two important metrics for any primary care practice are: (1) Timely Access and (2) Patient-physician Continuity. Timely access focuses on the ability of a patient to get access to a physician as soon as possible. Patient-physician continuity refers to building a strong or permanent relationship between a patient and a specific physician by maximizing patient visits to that physician. In the past decade, a new paradigm called advanced access or open access has been adopted by practices nationwide to encourage physician to “do today’s work today.” However, most clinics still reserve pre-scheduled appointments for long lead-time appointments due to …

Electric Power Market Modeling With Multi-Agent Reinforcement Learning, Nathanael K. Miksis

Masters Theses 1911 - February 2014

Agent-based modeling (ABM) is a relatively new tool for use in electric power market research. At heart are software agents representing real-world stakeholders in the industry: utilities, power producers, system operators, and regulators. Agents interact in an environment modeled after the real-world market and underlying physical infrastructure of modern power systems. Robust simulation laboratories will allow interested parties to stress test regulatory changes with agents motivated and able to exploit any weaknesses, before making these changes in the real world. Eventually ABM may help develop better understandings of electric market economic dynamics, clarifying both delineations and practical implications of market …

Terahertz And Microwave Detection Using Metallic Single Wall Carbon Nanotubes, Enrique A. Carrion

Masters Theses 1911 - February 2014

Carbon nanotubes (CNTs) are promising nanomaterials for high frequency applications due to their unique physical characteristics. CNTs have a low heat capacity, low intrinsic capacitance, and incredibly fast thermal time constants. They can also exhibit ballistic transport at low bias, for both phonons and electrons, as evident by their fairly long mean free paths. However, despite the great potential they present, the RF behavior of these nanostructures is not completely understood. In order to explore this high frequency regime we studied the microwave (MW) and terahertz (THz) response of individual and bundled single wall nanotube based devices. This thesis is …

Electromechanically Driven Chaotic Dynamics Of Voids In Metallic Thin Films, Dimitrios Maroudas, M. R. Gungor, V. Tomar

Dimitrios Maroudas

We report a systematic investigation of complex asymptotic states reached in the electromigration-driven morphological evolution of void surfaces in thin films of face-centered cubic metals with ⟨110⟩- and ⟨100⟩-oriented film planes under the simultaneous action of biaxial tension. The analysis is based on self-consistent dynamical simulations according to a realistic, well-validated, and fully nonlinear model. For ⟨110⟩-oriented film planes, we show that upon increasing the applied mechanical stress level, morphologically stable steady states transition to time-periodic states through a subcritical Hopf bifurcation. Further increase in the stress level triggers a sequence of period-doubling bifurcations that sets the driven nonlinear system …

Improved Utilization Of Biomass-Derived Carbon By Millisecond Co-Processing With Hydrogen Rich Feedstocks, Paul J. Dauenhauer, J. L. Colby, A. Bhan, L. D. Schmitt

Paul J. Dauenhauer

A reactor capable of improving the utilization of biomass-derived carbon during thermochemical conversion to synthesis gas is demonstrated experimentally. By co-processing hydrogen-deficient biomass (H/C[similar]2) with hydrogen-rich feedstocks (H/C≥4) through catalytic partial oxidation, 100% of the fuel carbon atoms fed to the reactor can be converted to CO.

Predicting Bite Force In Mammals: Two-Dimensional Versus Three-Dimensional Lever Models, Jl Davis, Se Santana, Er Dumont, Ir Grosse

Jeffrey M. Davis

Bite force is a measure of whole-organism performance that is often used to investigate the relationships between performance, morphology and fitness. When in vivo measurements of bite force are unavailable, researchers often turn to lever models to predict bite forces. This study demonstrates that bite force predictions based on two-dimensional (2-D) lever models can be improved by including three-dimensional (3-D) geometry and realistic physiological cross-sectional areas derived from dissections. Widely used, the 2-D method does a reasonable job of predicting bite force. However, it does so by over predicting physiological cross-sectional areas for the masseter and pterygoid muscles and under …

Kinetics Of Furfural Production By Dehydration Of Xylose In A Biphasic Reactor With Microwave Heating, George W. Huber, R. Weingarten, J. Cho, W. C. Conner Jr.

George W. Huber

In this paper we report a kinetic model for the dehydration of xylose to furfural in a biphasic batch reactor with microwave heating. There are four key steps in our kinetic model: (1) xylose dehydration to form furfural; (2) furfural reaction to form degradation products; (3) furfural reaction with xylose to form degradation products, and (4) mass transfer of furfural from the aqueous phase into the organic phase (methyl isobutyl ketone - MIBK). This kinetic model was used to fit experimental data collected in this study. The apparent activation energy for xylose dehydration is higher than the apparent activation energy …

Probing The Mechanism Of Silica Polymerization At Ambient Temperatures Using Monte Carlo Simulations, Peter A. Monson, Ateeque Malani, Scott M. Auerbach

Peter A. Monson

We have developed a model for silica polymerization at ambient temperatures and low densities and have studied this using reactive Monte Carlo simulations. The model focuses on SiO4 coordination with the energetics of hydrolysis and condensation reactions treated via the reaction ensemble. The simplicity of the model makes large system sizes accessible on a modest computation budget, although it is necessary to make additional assumptions in order to use the reactive Monte Carlo method as a simulation of the system dynamics. Excellent agreement for the evolution of the Qn distribution is obtained upon comparing the simulation results to experimental observations. …

Modeling Nanoparticle Formation During Early Stages Of Zeolite Growth: A Low-Coordination Lattice Model Of Template Penetration, Peter A. Monson, L. Jin, Scott M. Auerbach

Peter A. Monson

We present an extension of the simple-cubic lattice model developed by Jorge et al. [ J. Am. Chem. Soc. 2005, 127, 14388] of nanoparticle growth in the clear solution synthesis of silicalite-1 (MFI). We have implemented the model on a body-center cubic (bcc) lattice with second-neighbor repulsions, to generate a four-coordinate network that mimics the tetrahedral structure of silica. With this low-coordination lattice model we observe that the nanoparticles are metastable, possessing a core−shell structure with mostly silica in the core and templates forming a shell. Nanoparticle size is found to increase with temperature and decrease with solution pH, in …

Stabilization Of Thin Liquid Films Flowing Over Locally Heated Surfaces Via Substrate Topography, N Tiwari, Jm Davis

Jeffrey M. Davis

A long-wave lubrication analysis is used to study the influence of topographical features on the linear stability of noninertial coating flows over a locally heated surface. Thin liquid films flowing over surfaces with localized heating develop a pronounced ridge at the upstream edge of the heater. This ridge becomes unstable to transverse perturbations above a critical Marangoni number and evolves into an array of rivulets even in the limit of noninertial flow. Similar fluid ridges form near topographical variations on isothermal surfaces, but these ridges are stable to perturbations. The influence of basic topographical features on the stability of the …

Apolar Ortho-Phenylene Ethynylene Oligomers: Conformational Ordering Without Intermolecular Aggregation, Jing Jiang, Morris M. Slutsky, Ticora V. Jones, Gregory N. Tew

Gregory N. Tew

This paper describes the characterization of solvent induced folding behavior for non-polar (NP) alkoxy substituted ortho-phenylene ethynylene (o-PE) oligomers. Oligomers of lengths up to nine units have been shown to adopt helical conformations in heptane by NMR and CD spectroscopy, while chloroform promotes extended conformations. Surprisingly, the molar ellipticity values found in heptane for these oligomers are very small compared to other literature values of meta-phenylene ethynylene (m-PE) folded systems; however, comparable molar ellipticity values were found for a closed macrocyclic o-PE suggesting the weak ellipticity is a molecular-feature rather than a quality of folding indicator.

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

Otto Vogl

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

Otto Vogl

No abstract provided.

Scenario-Based Analysis Of Transportation Impacts In Case Of Dam Failure Flood Evacuation In Franklin County, Massachusetts (Paper # 10-1352), Haizhong Wang, Steven Andrews, John Collura, Daiheng Ni

Daiheng Ni

Emergency planning is an important practice that allows government officials and planners to prepare for disasters and to make prompt response s that can save lives and property . One of the foremost concern s during an emergency is to save as many lives as possible. Thus, whethe r people can leave the disaster areas safely and efficiently is a prime consideration in emergency planning and management. Usually, transportation planners use a four - step model to predict sy s- tem - level performance regarding how people move from on e place to another , and to determine the network …

Representing The Fundamental Diagram: The Pursuit Of Mathematical Elegance And Empirical Accuracy (Paper # 10-1354), Haizhong Wang, Jia Li, Qian-Yong Chen, Daiheng Ni

Daiheng Ni

The fundamental diagram, as the graphical representation of the relationships among traffic flow, speed, and density, has been the foundation of traffic flow theory and transportation engineering. 75 years after the seminal Greenshields model, a variety of models have been proposed to mathematically represent the speed-density relationship which underlies the fundamental diagram. Observed in these models was a clear path toward two competing goals: mathematical elegance and empirical accuracy. As the latest development of such a pursuit, this paper presents a family of speed-density models with varying numbers of parameters. All of these models perform satisfactorily and have physically meaningful …

Vehicular Ad Hoc Networks, Hossein Pishro-Nik, Shahrokh Valaee, Maziar Nekovee

Hossein Pishro-Nik

No abstract provided.

Ethics In Science & Engineering: Redefining Tools & Resources, Michelle S. Goncalves, Jane E. Fountain, Jessica Adamick, Marilyn Billings

Ethics in Science and Engineering National Clearinghouse

This report summarizes the main points of discussion of a national workshop convened to advance knowledge and practice for ethics in science and engineering. Following the enactment of the America COMPETES Act and its provisions to increase attention to ethics and the responsible conduct of research in science and engineering, the National Science Foundation (NSF) supported two beta site projects to advance understanding of the key dimensions required for a national online clearinghouse in ethics for science and engineering. The ESENCe Beta Site project, based at UMass Amherst and one of two such beta sites in the United States, thanks …