Engineering Commons^™

Power System Distributed Dynamic State Prediction, Md Ashfaqur Rahman, Ganesh Kumar Venayagamoorthy

Publications

The security of the power system can be enhanced with the prediction of the dynamic state variables. To increase the security, a distributed predictor is developed based on the Elman Recurrent Neural Network (ERNN) in this study. To develop a scalable distributed predictor, the whole network is divided in a number of ERNNs. They take the current and the previous actual states from its own and its neighbors to predict the near future values of the states. The concept is inspired from the Cellular Computational Network (CCN) framework. Each ERNN is a cell in the CCN framework. Through simulation, the …

A Real-Time Programmable Pulsatile Flow Pump For In Vitro Cardiovascular Experimentation, Rahul Raj Mechoor, Tyler Schmidt, Ethan Kung

Publications

Benchtop in vitro experiments are valuable tools for investigating the cardiovascular system and testing medical devices. Accurate reproduction of the physiologic flow waveforms at various anatomic locations is an important component of these experimental methods. This study discusses the design, construction, and testing of a low-cost and fully programmable pulsatile flow pump capable of continuously producing unlimited cycles of physiologic waveforms. It consists of a gear pump actuated by an AC servomotor and a feedback algorithm to achieve highly accurate reproduction of flow waveforms for flow rates up to 300 ml/s across a range of loading conditions. The iterative feedback …

Obstacle Filtering Alogrithm For Control Of An Autonomous Road Vehicle In Public Highway Traffic, Qian Wang, Beshah Ayalew

Publications

This paper presents an obstacle filtering algorithm that mimics human driver-like grouping of objects within a model predictive control scheme for an autonomous road vehicle. In the algorithm, a time to collision criteria is first used as risk assessment indicator to filter the potentially dangerous obstacle object vehicles in the proximity of the autonomously controlled vehicle. Then, the filtered object vehicles with overlapping elliptical collision areas put into groups. A hyper elliptical boundary is regenerated to define an extended collision area for the group. To minimize conservatism, the parameters for the tightest hyper ellipse are determined by solving an optimization …

Ultra Large Scale Manufacturing Challenges Of Silicon Carbide And Gallium Nitride Based Power Devices And Systems, Rajendra Singh, Amir A. Asif

Publications

The potential of wide band gap (WBG) semiconductors for manufacturing ultra-high performance power devices and systems is well known [1]. Historically, silicon carbide research is as old as is the discovery of transistors [2]. In recent years, significant progress has been made in reducing the bulk crystal defects. As a result, for niche applications some SiC and GaN products are currently in the market. However, silicon dominates the power devices and systems market. In an earlier publication [3] we pointed out that bulk crystal defects and process induced defects are still the major road blocks in creating a SiC and …

Energy Consumption Modeling And Analyses In Automotive Manufacturing Plant, Lujia Feng, Laine Mears

Publications

Manufacturing plants energy consumption accounts for a large share in world energy usage. Energy consumption modeling and analyses are widely studied to understand how and where the energy is used inside of the plants. However, a systematic energy modeling approach is seldom studied to describe the holistic energy in the plants. Especially using layers of models to share information and guide the next step modeling is rarely studied. In this paper, a manufacturing system temporal and organizational framework was used to guide the systematic energy modeling approach. Various levels of models were established and tested in an automotive manufacturing plant …

Integration Of Structural Health Monitoring And Intelligent Transportation Systems For Bridge Condition Assessment: Current Status And Future Direction, Sakib Mahmud Khan, Sez Atamturktur, Mashrur Chowdhury, Mizanur Rahman

Publications

Recent catastrophic bridge failures clearly indicate the urgent need for improving interval-based bridge inspection procedures that are qualitative and subjective in nature. Structural Health Monitoring (SHM) can mitigate the deficiencies of interval-based inspection techniques and provide real-time diagnostic information regarding the bridge structural health. SHM is not flawless however; the variability in the vehicle characteristics and traffic operational conditions makes it prone to false diagnosis. Recent advancements in the integration of SHM with intelligent transportation systems (ITS) demonstrate the successful use of ITS devices (e.g., traffic cameras, traffic detectors) in the analysis of bridge responses to multimodal traffic with varying …

Engineering Xylose Utilization In Yarrowia Lipolytica By Understanding Its Cryptic Xylose Pathway, Gabriel M. Rodriguez, Murtaza Shabbir Hussain, Lauren Gambill, Difeng Gao, Allison Yaguchi, Mark Blenner

Publications

Background

The oleaginous yeast, Yarrowia lipolytica, has been utilized as an industrial host for about 60 years for various applications. Recently, the metabolic engineering of this host has become increasingly popular due to its ability to accumulate lipids as well as improvements made toward developing new genetic tools. Y. lipolytica can robustly metabolize glucose, glycerol, and even different lipid classes. However, little is known about its xylose metabolizing capability. Given the desirability of having a robust xylose utilizing strain of Y. lipolytica, we performed a comprehensive investigation and elucidation of the existing components of its xylose metabolic pathway. …

Transformative Role Of Photovoltaics In Phasing Out Alternating Current Based Grid By Local Dc Power Networks For Sustainable Global Economic Growth, Rajendra Singh, Amir A. Asif, Ganesh K. Venayagamoorthy

Publications

For sustainable global economic growth, eradication of global energy poverty and addressing climate challenges, free fuel based solar and wind energy sources are the only viable solution for electricity generation. Due to inherent advantages, photovoltaics has emerged as the major source of electrical power. Local generation of direct current (DC) power by PV and the use of batteries for storing electrical power have the potential of transforming global electricity infrastructure to address the problems faced by alternating current (AC) based centralized power generation and long haul transmission and distribution.

Cost Estimation Model For Pan Based Carbon Fiber Manufacturing Process, Amaninder Singh Gill, Darian Visotsky, Laine Mears, Joshua D. Summers

Publications

A polyacrilonitrile (PAN) based carbon fiber manufacturing cost estimation model driven by weight is presented in this study. One of the biggest limiting factors in the large scale use of carbon fiber (CF) in manufacturing is its high cost. The costs involved in manufacturing the carbon fiber have been formalized into a cost model in order to facilitate the understanding of these factors. This can play a key role in manufacturing CF in a cost effective method. This cost model accounts for the fixed and variable costs involved in all stages of manufacturing, in addition to accounting for price elasticity.

Enrichment Of Diluted Cell Populations From Large Sample Volumes Using 3d Carbon-Electrode Dielectrophoresis, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Rodrigo Martinez-Duarte

Publications

Here, we report on an enrichment protocol using carbon electrodedielectrophoresis to isolate and purify a targeted cell population from sample volumes up to 4 ml. We aim at trapping, washing, and recovering an enriched cell fraction that will facilitate downstream analysis. We used an increasingly diluted sample of yeast, 106–102 cells/ml, to demonstrate the isolation and enrichment of few cells at increasing flow rates. A maximum average enrichment of 154.2 ± 23.7 times was achieved when the sample flow rate was 10 μl/min and yeast cells were suspended in low electrically conductive media that maximizes dielectrophoresis trapping. A COMSOL …

Energy, Economy, And Environment Analysis And Optimization On Manufacturing Plant Energy Supply System, Lujia Feng, Laine Mears, Cleveland Beaufort, Joerg Schulte

Publications

Increasing attention has recently been drawn to energy consumption in manufacturing plants. Facing the challenges from reducing emissions coupled with rising raw material prices and energy costs, manufacturers are trying to balance the energy usage strategy among the total energy consumption, economy, and environment, which can be self-conflicting at times. In this paper, energy systems in manufacturing environments are reviewed, and the current status of onsite energy system and renewable energy usage are discussed. Single objective and multicriteria optimization approaches are effectively formulated for making the best use of energy delivered to the production processes. Energy supply operation suggestions based …

Towards Additive Manufacturing Of Tungsten Carbide Using Renewable Resources, Monsur Islam, Rodrigo Martinez-Duarte

Publications

Here we present preliminary results towards additive manufacturing of carbides. A biopolymer-metal oxide gel composite composed of iota-carrageenan, chitin and tungsten trioxide (WO₃) was shaped and heat treated in order to obtain carbide structures. Upon heat treatment of this composite above 900 °C, a porous structure of tungsten carbide (WC) was obtained. The synthesis mechanism of WC was estimated using the result from XRD characterization. The synthesized WC was characterized with SEM, TEM and nitrogen absorption-desorption to investigate the morphology, particle size and pore size distribution. The carbonaceous materials retained the original shape. The ongoing work is on …

Shrinkage Analysis Of Carbon Micro Structures Derived From Su-8 Photoresist, Rucha Natu, Monsur Islam, Rodrigo Martinez-Duarte

Publications

We present preliminary results for the analysis of shrinkage of 3D carbon posts obtained by the pyrolysis of SU-8 precursor structures, in a technique known as Carbon MEMS. Though the shrinkage in the carbon structures is highly reproducible, there is a strong dependence of this shrinkage on the initial dimensions of the SU-8 pillars. Our hypothesis is that the shrinkage depends upon the area available for degassing during carbonization. In this work, this idea is used to analyze shrinkage in cylindrical pillars. The results obtained are studied based on the ratio of lateral and top surface area available for degassing …

Synthesis Of Titanium Oxycarbide Through Carbothermal Reduction Of Titanium Dioxide Nanoparticles And Renewable Biopolymers, Joshua Paul Flach, Paulo Henrique Figuereido De Lima, Joshua Craig Sparks, Monsur Islam, Rodrigo Martinez-Duarte

Publications

The goal of this is study is to explore the feasibility of a sustainable method of titanium oxycarbide synthesis through carbothermal reduction of a biopolymer composite. The reaction was studied at different temperatures in vacuum environments and at multiple TiO₂:C ratios in order to determine how these parameters affect the formation of titanium oxycarbide. The results indicate that both the heat treatment and the carbon ratios have a significant impact on the O/C ratio, and therefore, molecular composition and crystal structure of the titanium oxycarbide. The use of renewable biopolymers as a carbon source in the synthesis of …

3d Carbon-Electrode Dielectrophoresis For Enrichment Of A Small Cell Population From A Large Sample Volume, Monsur Islam, Rucha Natu, Maria Fernanda Larraga-Martinez, Guillermo Contreras-Dávila, Rodrigo Martinez-Duarte

Publications

Isolation and enrichment of cells from a diluted sample is necessary for different clinical applications. Here we have demonstrated the use of 3D carbon electrode dielectrophoresis (DEP) to process a diluted yeast sample featuring concentration as low as 102 cells/ml. The yeast cells in the sample were first trapped on carbon electrodes by implementing positive DEP force and then released and concentrated in a small volume of clean buffer. The maximum limit of the cell trapping for our device was found to be around 4000 cells. Using 10 µl/min, an enrichment of 154.2 ± 23.7 folds was achieved, where sample …

Assessing The Advantages Of Using Square Wave Signals For Particle Trapping In Carbon-Electrode Dielectrophoresis, Guillermo Contreras-Dávila, Jose I. Gomez-Quiñones, Victor H. Pérez-González, Rodrigo Martinez-Duarte

Publications

Here we present an improvement on the trapping efficiency of 3D carbon electrode Dielectrophoresis (carbonDEP) by using alternative signal geometries to the more traditional sine used to stimulate the electrodes. In particular, a square waveform is used. Theoretical analysis was based on the Root Mean Square (RMS) values and the Fourier Series Expansion of these signals. Computational modeling was performed to calculate the DEP force generated by the two signal waveforms and allowed for direct comparison. The trapping efficiency between square and sine signals was then determined experimentally. Given the same experiment characteristics, the use of square signals allows for …

Synthesis Of Tungsten Carbide From Bacterial Cellulose, Monsur Islam, Rodrigo Martinez-Duarte

Publications

Here we present preliminary experiments for the synthesis of carbide material using bacterial cellulose as carbon source. We used bacteria cellulose available as Nata de Coco and infiltrated it with tungsten trioxide (WO₃) nanoparticles. This composite was heat treated at 1300 °C in nitrogen atmosphere. The XRD pattern confirms the synthesis of tungsten carbide (WC) in the carbonaceous material, though a significant amount of metallic tungsten remained unreacted. SEM images shows that WC particles are present only at the surface of the carbon, which may be a consequence of improper infiltration or collapse of carbon matrix during heat …

Synchronization Of Pulse-Coupled Oscillators To A Global Pacemaker, Felipe Nunez, Yongqiang Wang, Andrew R. Teel, Francis J. Doyle Iii

Publications

Pulse-coupled oscillators (PCOs) are limit cycle oscillators coupled by exchanging pulses at discrete time instants. Their importance in biology and engineering has motivated numerous studies aiming to understand the basic synchronization properties of a network of PCOs. In this work, we study synchronization of PCOs subject to a global pacemaker (or global cue) and local interactions between slave oscillators. We characterize solutions and give synchronization conditions using the phase response curve (PRC) as the design element, which is restricted to be of the delay type in the first half of the cycle, interval (0,π)(0,π), and of the advance type in …

A Multi-Objective, Hub-And-Spoke Model To Design And Manage Biofuel Supply Chains, Mohammad S. Roni, Sandra D. Eksioglu, Kara G. Cafferty, Jacob J. Jacobson

Publications

In this paper we propose a multi-objective, mixed integer linear programming model to design and manage the supply chain for biofuels. This model captures the trade-offs that exist between costs, environmental and social impacts of delivering biofuels. The in-bound supply chain for biofuel plants relies on a hub-and-spoke structure which optimizes transportation costs of biomass. The model proposed optimizes the CO2" style="position: relative;" tabindex="0" id="MathJax-Element-1-Frame">CO2 emissions due to transportation-related activities in the supply chain. The model also optimizes the social impact of biofuels. The social impacts are evaluated by the number of jobs created. The multi-objective optimization model is …

Optimization Models To Integrate Production And Transportation Planning For Biomass Co-Firing In Coal-Fired Power Plants, Sandra D. Eksioglu, Hadi Karimi, Burak Eksioglu

Publications

Co-firing biomass is a strategy that leads to reduced greenhouse gas emissions in coal-fired power plants. Incentives such as production tax credit (PTC) are designed to help power plants overcome the financial challenges faced during the implementation phase. Decision makers at power plants face two big challenges. The first challenge is identifying whether the benefits from incentives such as PTC can overcome the costs associated with co-firing. The second challenge is identifying the extent to which a plant should co-fire in order to maximize profits. We present a novel mathematical model that integrates production and transportation decisions at power plants. …