Engineering Commons^™

Light Extraction Improvement Of Gan Leds Using Nano-Scale Top Transmission Gratings, Greg Chavoor, Xiaomin Jin, Ashton Ellaboudy, Xing-Xing Fu, Xiang-Ning Kang, Bei Zhang, Guo-Yi Zhang

Electrical Engineering

In this paper, we use a Finite-Difference Time-Domain GaN LED model to study constant wave (CW) average power of extracted light. The structure simulated comprises of a 200nm-thick p-GaN substrate, 50nm-thick MQW, 400nm-thick n-GaN substrate, and a 200nm n-GaN two-dimensional Photonic Crystal(2PhC) grating. We focus on optimizing three design parameters: grating period (A), grating height (d), and fill factor (FF). In the primary set of simulations, we fix the fill factor at 50% and simulate ten different grating periods (100 to 1000nm in steps of 100nm) and four different grating heights (50 to 200nm in steps of 50nm), and calculate …

An Optical Analysis Of The Blowoff Behavior For Bluff Body-Stabilized Flames In Vitiated Flow, Trevor Jensen

Master's Theses

In bluff body-stabilized flames, a variety of physical phenomena contribute to the flame destabilization as lean blowoff is approached. These effects include increased strain on the flame shear layers, decreased attenuation of Bénard-von Kármán vortex shedding, and the presence of thermoacoustic instabilities. Lean, bluff body-stabilized flames were studied in an enclosed rectangular-duct, turbulent combustion rig with a triangular flame holder under vitiated conditions with both symmetric and asymmetric fuel distributions. Air and fuel flows within the rig were characterized using a PIV system and a continuous emissions gas analyzer, respectively.

High-speed videos of these flames undergoing blowoff were taken to …

Glucose Biosensor Using Electrospun Mn2o3-Ag Nanofibers, Shan Huang

Master's Theses

The highly porous Mn₂O₃-Ag nanofibers were fabricated by a facile two-step procedure (electrospinning and calcination) and then employed as the immobilization matrix for glucose oxidase (GOD) to construct an amperometric glucose biosensor. A notable enhancement of direct electron transfer between GOD and the electrode is observed at the Mn₂O₃-Ag-GOD modified electrode with a fast electron transfer rate constant. The biosensor also shows fast response to glucose, high sensitivity (40.60 μA×mM^-1×cm^-2), low detection limit (1.73 µM at S/N=3), low K_m,app value and excellent selectivity. These results indicate that …

Experimental And Numerical Investigations Of Tubular-Shaped Direct Methanol Fuel Cells (Dmfcs), Travis R. Ward

Master's Theses

This study focuses on both the numerical and experimental investigations of the novel, passively operated, tubular-shaped, Direct Methanol Fuel Cell (DMFC) as an alternative geometry to the traditional planar-shaped fuel cell. The benefit of the tubular geometry compared to the planar geometry is the higher instantaneous volumetric power density provided by the larger active area, which could be beneficial in applications that require a high instantaneous power while occupying a small volume. First, a two-dimensional, two-phase, non-isothermal model was developed to investigate the steady-state performance and design characteristics of a tubular-shaped, passive DMFC. It was found that a higher ambient …

Improvement Of Solar Cell Efficiency Using Nano-Scale Top And Bottom Grating, Xiaomin Jin, Ashton Ellaboudy, Greg Chavoor

Electrical Engineering

We study solar-cell designs using nano-grating on both top (transmission) and bottom (reflection) of the solar cell. First, we perform simulations based on rigorous coupled wave analysis (RCWA) to evaluate the diffraction top gratins. In RCWA method, we calculate up to 20 harmonics, and sweep the launch angle of incident light from 0 to 90 degree. The incident light varies from100nm to 1200nm wavelength. Triangular grating can achieve higher light absorption compared to the rectangular grating. The best top grating is around 200nm grating period, 100nm grating height, and 50% filling factor, which responses to 37% improvement for triangular grating …

Storm Damage Survey Report Goderich 2011 August, Randy Mawson, David Sills, Arnold Ashton, Ian Hay

Goderich August 21 2011 F3 Tornado Associated Files

Sifto salt mine at lakeshore had signficant damage, with various machinery, booms, and buildings damaged or destroyed. One Sifto employee was killed. The tornado struck right through the exact centre of the downtown, causing F3 damage there. At the central square with the courthouse, the north side had trees down from the north, and the south side had trees down from the south. Many heritage brick buildings heavily damaged. Vehicles tossed and rolled. Some of the buildings hardest-hit by the tornado, like the landmark Victoria Street United Church and the former opera house, have been torn down. In residential areas, …

Plasmonic Nanogels With Robustly Tunable Optical Properties, Tao Cong, Satvik N. Wani, Georo Zhou, Elia Baszczuk, Radhakrishna Sureshkumar

Biomedical and Chemical Engineering - All Scholarship

Low viscosity fluids with tunable optical properties can be processed to manufacture thin film and interfaces for molecular detection, light trapping in photovoltaics and reconfigurable optofluidic devices. In this work, self-assembly in wormlike micelle solutions is used to uniformly distribute various metallic nanoparticles to produce stable suspensions with localized, multiple wavelength or broad-band optical properties. Their spectral response can be robustly modified by varying the species, concentration, size and/or shape of the nanoparticles. Structure, rheology and optical properties of these plasmonic nanogels as well as their potential applications to efficient photovoltaics design are discussed.

Effects Of Sprinkler, Partial Sprinkler/Drip, And Drip Only Irrigation On Strawberry Transplants 2010-2011, Stuart Styles

BioResource and Agricultural Engineering

The purpose of the project is to develop an analysis of the current irrigation practices of the strawberry growers on the Central Coast of California. The primary research evaluation is during the establishment of transplants where sprinklers are typically used even though drip irrigation is available. Growers have been selected from Oxnard, Santa Maria, and Watsonville to provide a good cross section of the different strawberry growing areas.

The specific objectives of the project are to: (1) set up a research areas and control plots on a demonstration scale, (2) determine the key factors that affect the problems in early …

Fluid Structure And Boundary Slippage In Nanoscale Liquid Films, Nikolai V. Priezjev

Mechanical and Materials Engineering Faculty Publications

The book describes the concerted efforts of a large European research project and the achievements of additional leading research groups. The reported knowledge and expertise should support in the innovation and integration of often separated unitary processes. Sampling, cell lysis and DNA/RNA extraction, DNA hybridisation detection micro- and nanosensors, microfluidics, together also with computational modelling and risk assessment can be integrated in the framework of the current and evolving European regulations and needs. The development and uptake of molecular methods is revolutionizing the field of waterborne pathogens detection, commonly performed with time-consuming cultural methods. The molecular detection methods are enabling …

Ceas E-News 08.18.2011, College Of Engineering And Applied Sciences

College of Engineering and Applied Sciences News

Casting Challenge, First Annual SAE Alumni Drive, Best Poster

Design Optimization Of Linear Precoders For Complex Vector Gaussian Channelswith Finite Alphabet Inputs, Chengshan Xiao, Yahong Rosa Zheng, Zhi Ding

Electrical and Computer Engineering Faculty Research & Creative Works

We study the design optimization of linear precoders that maximize the mutual information in complex-valued vector Gaussian channels under finite alphabet inputs. It is well known that mutual information of a vector channel with discrete constellation source is a highly nonlinear and nonconcave function of the linear precoder matrix G, thereby complicating the precoder design optimization. in this paper, we show that the mutual information is a concave function of W = GhHhHG, where H is the complex-valued channel matrix and superscript "h" represents conjugate transpose. We further propose an iterative algorithm for solving the globally optimal linear precoder G. …

Proportionate Affine Projection Sign Algorithms For Sparse System Identification In Impulsive Interference, Zengli Yang, Yahong Rosa Zheng, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

Two proportionate affine projection sign algorithms (APSAs) are proposed for system identification applications, such as network echo cancellation (NEC), where the impulse response is often real valued with sparse coefficients and long filter length. the proposed proportionate-type algorithms can achieve fast convergence and low steady-state misalignment by adopting a proportionate regularization matrix to the APSA. Benefiting from the characteristic of l1-norm algorithms, affine projection, and proportionate matrix, the new algorithms are robust to impulsive interferences and colored input and achieve much faster convergence rate in sparse impulse responses than the original APSA, the normalized sign algorithm (NSA), and the proportionate …

Note: Miniature 120-Kv Autonomous Generator Based On Transverse Shock-Wave Depolarization Of Pb(Zr0.52ti0.48)O₃ Ferroelectrics, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

The design of autonomous ultrahigh-voltage generators with no moving metallic parts based on transverse explosive shock wave depolarization of Pb(Zr_0.52Ti_0.48)O₃ (PZT 5248) poled ferroelectrics was explored and studied. It follows from experimental results that the output voltage produced by the shock-wave ferroelectric generators (FEGs) is directly proportional to the number of PZT 5248 elements connected in series. It was demonstrated that miniature FEGs (volume less than 180 cm³) were capable of reliably producing output voltage pulses with amplitudes exceeding 120 kV which is the record reported in open literature.

Ros-Drill Automation: Visual Feedback Control And Rotational Motion Tracking, Jhon F. Diaz

Master's Theses

ICSI (intra-cytoplasmic sperm injection) has attracted research interest from both biological and engineering groups. The technology is constantly evolving to perform this procedure with precision and speed. One such development is the contribution of this thesis. We focus on a relatively recent procedure called Ros-Drill^© (rotationally oscillating drill), of which the early versions have already been effectively utilized for the mice. In the first part, we present a procedure to automate a critical part of the operation: initiation of the rotational oscillation, Visual feedback is used to track the pipette tip. Predetermined species-specific penetration depth is successfully utilized …

Comparison Of Tdnn And Rnn Performances For Neuro-Identification On Small To Medium-Sized Power Systems, Diogenes Molina, Jiaqi Liang, Ron Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

For Artificial Neural Networks (ANN) to become more widely used in power systems and the future smart grids, ANN based algorithms must be capable of scaling up as they try to identify and control larger and larger parts of a power system. This paper goes through the process of scaling up an ANN based identifier as it is driven to identify increasingly larger portions of a power system. Distributed and centralized approaches for scaling up are taken and the pros and cons of each are presented. the New England/New York 68-bus power network is used as the test bed for …

Optimal Location And Sizing Of Energy Storage Modules For A Smart Electric Ship Power System, Chuan Yan, Ganesh K. Venayagamoorthy, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

The Navy's next generation electric ship's power system will support high energy loads and critical equipment. Energy storage modules will be needed to meet the demands of these loads as well as increase the overall high quality of service. This paper describes an approach to evaluate the impact of energy storage module location and sizing for ship survivability and quality of service. Specifically, a multi-objective optimization algorithm, the multi-objective particle swarm optimization -, is used to obtain Pareto optimal solutions considering survivability, quality of service, and cost. Results based multi-objective particle swarm optimization study show that optimal ESM location and …

Wide Area Monitoring In Power Systems Using Cellular Neural Networks, Bipul Luitel, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

The demand of power and the size and complexity of the power system is increasing. Wide area monitoring and control is an integral part in transitioning from the traditional power system to a Smart Grid. However, wide area monitoring becomes challenging as the size of the electric power grid, and consequently the number of components to be monitored, grows. Wide area monitor (WAM) designed using feed-forward and feedback neural network architectures do not scale up to handle the growing complexity of the Smart Grid. in this paper, cellular neural network (CNN) is presented as a way to provide scalability in …

Thermal Model For Lithium Ion Battery Pack With Mixed Parallel And Series Configuration, Meng Guo, Ralph E. White

Faculty Publications

In this work, a mathematical thermal model for lithium ion battery pack with specific configuration was developed by coupling the single particle model and energy balance equation with basic circuit constraints. The temperature variation at different parts of the battery pack was considered in charge/discharge operations, and the dependency of cell parameters on temperature were taken into account. The model was validated by comparing the simulated current, voltage, and temperature profiles with experimental data. Case studies such as battery balancing and circuit interruption were also performed and discussed.

Adaptive Critic Design Based Dynamic Optimal Power Flow Controller For A Smart Grid, Jiaqi Liang, Ronald G. Harley, Ganesh K. Venayagamoorthy

Electrical and Computer Engineering Faculty Research & Creative Works

An adaptive critic design (ACD) based dynamic optimal power flow control (DOPFC) is proposed in this paper as a solution to the smart grid operation in a high short-term uncertainty and variability environment. with the increasing penetration of intermittent renewable generation, power system stability and security need to be ensured dynamically as the system operating condition continuously changes. the proposed DOPFC dynamically tracks the power system optimal operating point by continuously adjusting the steady state set points from the traditional OPF algorithms. the ACD technique, specifically the dual heuristic dynamic programming (DHP), is used to provide nonlinear optimal control, where …

Development Of Novel Bio/Nano Interfaces For Materials Science And Biomedical Applications, Carlee Ashley

Chemical and Biological Engineering ETDs

Virus-like particles (VLPs) of MS2 bacteriophage possess a variety of characteristics that enable their use in biomedical and materials science applications. MS2 VLPs are perfectly monodisperse and possess a highly regular periodic structure. Their protein capsids can be modified in precise locations via chemical conjugation or genetic display of peptides, and their interior volumes can be readily loaded with a variety of non-genomic materials by taking advantage of their ability to self-assemble in the presence of RNA and RNA-modified cargos. Using peptides identified by filamentous phage display, I have demonstrated the utility of MS2 VLPs as targeted nanocarriers capable of …

Contribution Of Proteoglycan Osmotic Swelling Pressure To The Compressive Properties Of Articular Cartilage, Eunhee Han, Silvia S. Chen, Stephen M. Klisch, Robert L. Sah

Mechanical Engineering

The negatively charged proteoglycans (PG) provide compressive resistance to articular cartilage by means of their fixed charge density (FCD) and high osmotic pressure (π_PG), and the collagen network (CN) provides the restraining forces to counterbalance π_PG. Our objectives in this work were to: 1), account for collagen intrafibrillar water when transforming biochemical measurements into a FCD-π_PG relationship; 2), compute π_PG and CN contributions to the compressive behavior of full-thickness cartilage during bovine growth (fetal, calf, and adult) and human adult aging (young and old); and 3), predict the effect of depth from the articular …

Mutant Alcohol Dehydrogenase Leads To Improved Ethanol Tolerance In Clostridium Thermocellum, Steven D. Brown, Adam M. Guss, Tatiana V. Karpinets, Jerry M. Parks

Dartmouth Scholarship

Clostridium thermocellum is a thermophilic, obligately anaerobic, Gram-positive bacterium that is a candidate microorganism for converting cellulosic biomass into ethanol through consolidated bioprocessing. Ethanol intolerance is an important metric in terms of process economics, and tolerance has often been described as a complex and likely multigenic trait for which complex gene interactions come into play. Here, we resequence the genome of an ethanol-tolerant mutant, show that the tolerant phenotype is primarily due to a mutated bifunctional acetaldehyde-CoA/alcohol dehydrogenase gene (adhE), hypothesize based on structural analysis that cofactor specificity may be affected, and confirm this hypothesis using enzyme assays. …

Software Development Approach For Discrete Simulators, Grzegorz Chmaj, Dawid Maksymilian Zydek

Electrical & Computer Engineering Faculty Research

Simulation is the most common approach to perform the problem research. Among several types of simulation, the most common way is the discrete simulation, which assumes the division of the time scale into fixed length time slots. Depending on investigated problem, simulation packages may be used or it could be necessary to design and create own simulation system. In this paper, we propose the complete pre-study scheme and the most commonly appearing implementation problems with suggested solutions. We also describe how to implement the exemplary simulator in C++.

Applied Methodology For Computational Formulation In International Expansion Strategy Of Taiwanese Semiconductor Industry, Cher-Min Fong, Hoang Linh Nguyen

Journal of Marine Science and Technology–Taiwan

This study seeks to contribute to entry mode literature by introducing the concept of “corporate culture diversity”. Compared to multinational enterprises (MNEs) from developed countries, Taiwan’s MNEs have shorter history of internationalization. Therefore, international learning is critical to their entry modes. We examined an original determinant of entry mode choice, proposed and tested the operationalization for a new theoretical construct, namely “corporate culture diversity”. Hypotheses were developed on the entry modes in relation to cultural diversity of a firm’s international experience, a step beyond the conventional theory of how national cultural differences influence the international expansion strategy. The hypotheses were …

An Integrated Quantitative Risk Analysis Method For Major Construction Accidents Using Fuzzy Concepts And Influence Diagram, Yong-Huang Lin, Chen-Chung Lin, Yaw-Yauan Tyan

Journal of Marine Science and Technology–Taiwan

The accident factor identification and risk assessment is an essential requirement for prevention of major construction accidents in the construction project process. An integrated quantitative risk assessment (IQRA) method has been proposed in this paper to overcome the problems of difficult to quantify accident probability for construction industry. The proposed approach employs influence diagram and fuzzy theory to estimate accident probability and to deal with the imprecision inherent to the process of subjective judgment. A case study that evaluates accident probability of diaphragm wall collapse is presented to illustrate the use of this methodology and to demonstrate its capability.

Adaptive Kernel Smoothing Regression Using Vector Quantization, Federico Montesino Pouzols, Amaury Lendasse

Engineering Management and Systems Engineering Faculty Research & Creative Works

A Method for Performing Kernel Smoothing Regression in an Online Adaptive Manner is Presented. the Approach Proposed is to Apply Kernel Smoothing Regression on an Incremental Estimation of the (Evolving) Probability Distribution of the Incoming Data Stream Rather Than the Sequence of Observations. This is Achieved by Performing Vector Quantization on the Incoming Stream. in Addition, the Kernel Bandwidth is Adapted Online using a Criterion based on the Median Absolute Deviation Estimator Which Can Be Computed Efficiently Online. Thus, Adaptive Kernel Smoothing Regression is Computed on an Evolving Density Estimation. the Method is Fast and Suitable for Modeling Streams of …

Mechanism Of Thermal Conductivity Reduction In Few-Layer Graphene, Druv Singh, Jayathi Y. Murthy, Timothy S. Fisher

Birck and NCN Publications

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. However, reflection symmetry is only weakly broken with the addition of multiple layers, and out-of-plane acoustic phonons still dominate thermal conductivity. We also find that reduction in thermal conductivity is …

Experimental Analysis For Thermal Performance Of A Vapor Chamber Applied To High-Performance Servers, Rong-Tsu Wang, Jung-Chang Wang, Tien-Li Chang

Journal of Marine Science and Technology–Taiwan

This article conducts experimental analysis using the window program VCTM V1.0 to investigate the thermal performance of a vapor chamber and then applies the findings to a high-performance server. The experimental method is derived from a novel formula for the effective thermal conductivity of a vapor chamber and functions to calculate its thermal performance. Results show that the maximum heat flux is over 100 W/cm2 , and the effective thermal conductivity is many times higher than the copper heat spreaders. The maximum effective thermal conductivity is 870 W/m°C according to the novel formula, and comparing it with the experimental value, …

A Generalized Approach To The Solution Of One-Dimensional Stock-Cutting Problem For Small Shipyards, Ahmet Cemil Dikili, Baris Barlas

Journal of Marine Science and Technology–Taiwan

A generalized approach is introduced for the optimization of one-dimensional cutting stock problem (1D-CSP), which occurs in wide variety of engineering manufacturing processes especially in ship building industry. Instead of making preliminary specifications and accordingly ignoring many alternative arrangements, the suggested optimization technique selectively considers feasible arrangements by eliminating majority of the possible but inefficient arrangements thus rendering the problem solvable for practical applications. The introduced approach, which minimizes the piece arrangement plans and trim losses in the material, achieves the ideal solution implied by the analytical methods. Another important advantage of the present method is its ability to produce …

Experimental And Numerical Study On The Flow Visualization In A Tri-Helical Static Mixer, Kuo-Tung Chang, Jer-Huan Jang, Teng-Chuang Lai, Jun-Nan Chen

Journal of Marine Science and Technology–Taiwan

In this work, the flow visualization in a tri-helical static mixer has been investigated in detailed both experimentally and numerically. The static mixer used for the present study consists of four elements with a series of alternating left and right helical elements. Each element has the aspect ratio of 1.5 (i.e., L/D = 1.5) and twisted angle of 180°. The objective of this investigation is mainly to explore the flow pattern inside a tri-helical static mixer due to its novelty and originality. It is clearly observed that the flows at the trailing edge for both numerical and experimental results are …