Engineering Commons^™

A Static Voltage Security Region For Centralized Wind Power Integration-Part I: Concept And Method, Tao Ding, Qinglai Guo, Rui Bo, Hongbin Sun, Boming Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

When large wind farms are centrally integrated in a power grid, cascading tripping faults induced by voltage issues are becoming a great challenge. This paper therefore proposes a concept of static voltage security region to guarantee that the voltage will remain within operation limits under both base conditions and N-1 contingencies. For large wind farms, significant computational effort is required to calculate the exact boundary of the proposed security region. To reduce this computational burden and facilitate the overall analysis, the characteristics of the security region are first analyzed, and its boundary components are shown to be strictly convex. Approximate …

Blackbox Macro-Modeling Of The Nonlinearity Based On Volterra Series Representation Of X-Parameters, Xiaoyan Y.Z. Xiong, Li (Lijun) J. Jiang, José E. Schutt-Ainé, Weng Cho Chew

Electrical and Computer Engineering Faculty Research & Creative Works

Volterra series representation is a powerful mathematical model for nonlinear devices. However, the difficulties in determining higher-order Volterra kernels limited its broader applications. This paper proposed a systematic approach that enables a convenient extraction of Volterra kernels from X-parameters for the first time. Then the Vandermonde method is employed to separate different orders of Volterra kernels at the same frequency, which leads to a highly efficient extraction process. The proposed Volterra series representation based on X-parameters is further benchmarked for verification. The proposed new algorithm is very useful for the blackbox macro-modeling of nonlinear devices and systems.

A Hybrid Time-Domain Discontinuous Galerkin-Boundary Integral Method For Electromagnetic Scattering Analysis, Ping Li, Yifei Shi, Li (Lijun) Jun Jiang, Hakan Baǧci

Electrical and Computer Engineering Faculty Research & Creative Works

A scheme hybridizing discontinuous Galerkin time-domain (DGTD) and time-domain boundary integral (TDBI) methods for accurately analyzing transient electromagnetic scattering is proposed. Radiation condition is enforced using the numerical flux on the truncation boundary. The fields required by the flux are computed using the TDBI from equivalent currents introduced on a Huygens' surface enclosing the scatterer. The hybrid DGTDBI ensures that the radiation condition is mathematically exact and the resulting computation domain is as small as possible since the truncation boundary conforms to scatterer's shape and is located very close to its surface. Locally truncated domains can also be defined around …

Magnetoelectric Dipole Antenna Arrays, Shulabh Gupta, Li (Lijun) Jun Jiang, Christophe Caloz

Electrical and Computer Engineering Faculty Research & Creative Works

A planar magnetoelectric (ME) dipole antenna array is proposed and demonstrated by both full-wave analysis and experiments. The proposed structure leverages the operation of composite right/left-handed transmission lines under balanced conditions to form high-gain magnetic radiators, combined with radial conventional electric radiators, where the overall structure is excited by a single differential feed. The traveling-wave-type nature of the proposed ME-dipole antenna enables the formation of directive arrays with high-gain characteristics and scanning capability. Peak gains of 10.84 dB and 5.73 dB are demonstrated for the electric dipole and magnetic-dipole radiation components, respectively. © 1963-2012 IEEE.

Cosimulation Of Electromagnetics-Circuit Systems Exploiting Dgtd And Mna, Ping Li, Li (Lijun) Jun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

A hybrid electromagnetics (EM)-circuit simulator exploiting the discontinuous Galerkin time domain (DGTD) method and the modified nodal analysis (MNA) algorithm is developed for analyzing hybrid distributive and nonlinear multiport lumped circuit systems. The computational domain is split into two subsystems. One is the EM subsystem that is analyzed by DGTD, while the other is the circuit subsystem that is solved by the MNA method. The coupling between the EM and circuit subsystems is enforced at the lumped port where related field and circuit unknowns are coupled via the use of numerical flux, port voltages, and current sources. Since the spatial …

Helmholtz Decomposition Based On Integral Equation Method For Electromagnetic Analysis, Xiaoyan Y.Z. Xiong, Wei E.I. Sha, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Helmholtz decomposition (HD) is a vector analysis fundamental tool and plays an important role in electromagnetics (EM) and microwave engineering. Instead of applying HD to the EM solving process, this article proposes an integral equation based rigorous HD process to extract and analyze the known EM field. It provides much clearer insight into field coupling and radiation mechanism that is valuable to electromagnetic interference (EMI) and electromagnetic compatibility (EMC) analysis. Compared to the loop-tree based decomposition that is a quasi-HD, the proposed method is rigorous and frequency-independent. The algorithm verification and its application to coupling and resonating problems are presented. …

Microcavity Strain Sensor For High Temperature Applications, Amardeep Kaur, Steve Eugene Watkins, Jie Huang, Lei Yuan, Hai Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

A microcavity extrinsic Fabry-Perot interferometric (EFPI) fiber-optic sensor is presented for measurement of strain. The EFPI sensor is fabricated by micromachining a cavity on the tip of a standard single-mode fiber with a femtosecond (fs) laser and is then self-enclosed by fusion splicing another piece of single-mode fiber. The fs-laser-based fabrication makes the sensor thermally stable to sustain temperatures as high as 800°C. The sensor exhibits linear performance for a range up to 3700 µε and a low temperature sensitivity of only 0.59 pm/°C through 800°C.

Casimir Force For Complex Objects Using Domain Decomposition Techniques, Phillip R. Atkins, Weng Cho Chew, Mao Kun Li, Lin E. Sun, Zu Hui Ma, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

A method for calculating the Casimir force between large, complex 3D objects is presented. Difficulties have previously arisen in broadband multiscale calculation using CEM methods. To expand the range of problems that can be calculated, we use an integral equation, domain decomposition method (DDM) and argument principle to derive the Casimir force formula. The broadband integral equation DDM, which is the augmented equivalence principle algorithm (A-EPA), allows for an efficient broadband solution of large, complex objects. A-EPA subdivides a complex problem into separate smaller subproblems that are later recombined into a reduced matrix. This yields a reduced number of unknowns …

Traveling-Wave Antennas With Exotic Radiation Patterns, S. Gupta, C. Caloz, L. (Lijun) J. Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

Two type of planar leaky-wave antennas are presented which are capable of providing combined electric and magnetic-dipole radiation responses from a single electromagnetic structure, leading to exotic radiation pattern characteristics. Their principle and radiation characteristics are discussed in details.

Network Resilience Improvement Using Link Additions, Mohammed J. F. Alenazi, Egemen K. Çetinkaya, James P. G. Sterbenz

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Technology And Engineering Education Doctoral Students' Perceptions Of Their Profession, Gene Martin, John Ritz, Michael Kosloski

STEMPS Faculty Publications

The growth and vitality of both technology and engineering education professions rely on the quality of contributions of its new and emerging leaders. Many of these leaders are currently enrolled students in doctoral programs. These students will be challenged to assume leadership roles in which they are not currently engaged (Ehrenberg, Jakubson, Groen, So, & Price, 2007). Some students may choose to focus their careers in developing new curricula; some will become active in grant writing and grant procurement some will choose to serve as officers in their professional organizations; and others will contribute to the body of literature in …

Suitable Catalyst Bed Arrangement Of Silica-Based Supported Tungstenand Hydrotalcite Catalysts For Propylene Production From 1-Butene, Sirada Sripinun

Chulalongkorn University Theses and Dissertations (Chula ETD)

The research studied the design of suitable catalyst beds of hydrotalcite and the modified silica supported tungsten for propylene production from 1-butene. The study started with performing reactions at various values of gas hourly space velocity, feed composition and temperature. Then the reaction rate expressions for each catalyst were determined. It was found that the models could predict well the experimental results. The models were further used to simulate the reaction performance of reactors packed with different catalyst beds. The performance was shown in terms of molar flow rate of propylene and yield of propylene. The performance of the catalyst …

Simulation Of Temperature Distribution In A Thermal Drying Oven Based On Three Dimensional Cfd Model, Patsarawan Lipikanjanakul

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research presents a study of air velocity in a thermal drying oven in drying zone. To reduce a heat loss, a mass flow rates are decreased from 100% to 10%. The effect of the mass flow rate can be divided into three parts; air velocity, air temperature, and concentration of solvent. A three-dimensional CFD with a non-isothermal model and a transport of diluted species were simulated by using COMSOL. For ensuring the result, all results are compared with MATLAB program by focusing in two-direction (length-height). The parameters of air velocity that uses in this program is the results of …

การผลิตไบโอบิวทานอลจากการย่อยสลายของเปลือกถั่วเหลือง, มานพ บุญเจริญ

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ทำการศึกษาการย่อยสลายเปลือกถั่วเหลืองด้วยกรดเพื่อใช้เป็นสารตั้งต้นในการผลิตอะซิโตน เอทานอล และบิวทานอล ด้วยเชื้อ Clostridium saccharobutylicum ATCC BAA 117 การย่อยสลายทำในหม้อนึ่งไอน้ำความดันสูงที่ความเข้มข้น อัตราส่วนของแข็งต่อของเหลว และเวลาในการทำปฏิกิริยาที่ค่าต่างๆ สภาวะที่ดีที่สุดสำหรับการผลิตน้ำตาลรีดิวซ์ที่สูงและสารยับยั้งที่ต่ำ มีดังนี้ ความเข้มข้นกรดร้อยละ 5 โดยปริมาตร อัตราส่วนของแข็งต่อของเหลว 1 ต่อ 5 เวลาการย่อยสลาย 15 นาที น้ำตาลไฮโดรไลเซทประกอบด้วยน้ำตาลรีดิวซ์รวม 31.86 กรัมต่อลิตร รวมทั้งเฟอร์ฟูรัล 0.66 กรัมต่อลิตร และไฮดรอกซีเมทิลเฟอร์ฟูรัล 0.059 กรัมต่อลิตร เฟอร์ฟูรัลที่ความเข้มข้น 0.05 กรัมต่อลิตร ได้แสดงฤทธิ์ยับยั้งการเจริญเติบโตของ C. saccharobutylicum ATCC BAA 117 แต่ไฮดรอกซีเมทิลเฟอร์ฟูรัลไม่มีผลกระทบ การบำบัดโดยใช้ Overliming ด้วยแคลเซียมไฮดรอกไซด์ และการดูดซับด้วยเรซิน XAD-4 และถ่านกัมมันต์ ช่วยปรับปรุงน้ำตาลไฮโดรไลเซทให้สามารถใช้ในการหมักได้อย่างมีนัยสำคัญ การหมักแบบกะที่อุณหภูมิ 35 องศาเซลซียส ค่าความเป็นกรดด่าง 5.5 เมื่อใช้น้ำตาลไฮโดรไลเซท (30-65 กรัมต่อลิตร) ที่ชนิดแหล่งและความเข้มข้นแหล่งไนโตรเจนต่างๆ การผลิตตัวทำละลายที่เหมาะสมจะได้รับจากที่สภาวะอุณหภูมิ 35 องศาเซลเซียส ค่าความเป็นกรดด่าง 5.5 ในอาหารน้ำตาลไฮโดรไลเซทที่ประกอบด้วยน้ำตาลรีดิวซ์ 65 กรัมต่อลิตร ยีตส์สกัด แอมโมเนียมอะซิเตทและน้ำแช่ข้าวโพด ตัวทำละลายรวมมีค่า 15.69 กรัมต่อลิตร ประกอบด้วยอะซิโตน บิวทานอล และเอทานอลเท่ากับ 12.15, 15.69 และ 2.39 กรัมต่อลิตร ตามลำดับ มีผลได้ตัวทำละลายเท่ากับ 0.46 และอัตราการผลิตตัวทำละลาย 0.37 กรัมต่อลิตรต่อชั่วโมง ในงานวิจัยนี้แสดงให้เห็นว่าเปลือกถั่วเหลืองสามารถใช้เป็นแหล่งคาร์บอนที่มีศักยภาพสำหรับการหมักเพื่อผลิตอะซิโตน เอทานอล และบิวทานอล

Propane Dehydrogenation To Olefins Via Modified Pt-Based/Γ-Al2o3, Napat Hataivichian

Chulalongkorn University Theses and Dissertations (Chula ETD)

The effect of transition metal(X) added on Pt/Al2O3 catalyst was studied in propane dehydrogenation reaction at 500oC. The metal contents were fixed at 0.3%wt for Pt, 4%wt for X. It was found that the transition metal had an effect upon reducibility of platinum due to its interaction with X-containing structure, resulting in the presence of Pt metal was decreased and lower initial conversions are observed. However, the final conversions are not decreased, thus the bimetallic catalysts had a better stability because the transition metal sites attracted propylene from Pt sites, so there is no propylene remain adsorbed on Pt site, …

Metathesis Of Ethylene And 2-Butene For Propylene Production Using Naoh Modified Wo3/Sio2 Catalysts, Surasa Maksasithorn

Chulalongkorn University Theses and Dissertations (Chula ETD)

WO3-based catalyst is one of the most successful catalysts for producing propylene via olefin metathesis. Traditionally, it is prepared by an incipient wetness method. This suffer from severe limitations such as inhomogeneity of the WO3 deposit, alteration of the texture (pore plugging, etc.) and genesis of inactive species (WO3 crystals), resulting in low catalytic performance. The present study exploits innovative preparation methods for more efficient WO3-based catalysts by using two methods of one step preparation including non-hydrolytic sol-gel route and aerosol-assisted sol-gel process. These methods offer good control on the final catalyst composition, provide mixed oxides with excellent textures, feature …

An Environmentally-Friendly Design To Reduce Energy Loss By Heat Transfer Through Windows, Andrew Li

Honors Theses

With windows as main areas of energy loss in residential environments, a market exists for a product to act a removable barrier which improves heat transfer for cases of extreme temperatures in seasonal weather. Such a product would allow consumers to save money in the long run without permanently losing the use of their windows when the weather is mild and such an apparatus is not needed. This project designs such a product using an assembly of polished aluminum foil for low radiation emissivity, ABS plastic for an insulating material with low conductivity, and an aluminum glass mirror pane which …

The Cooling Effect Of Cryotherapy On Power And Accuracy In The Pitching Arms Of Baseball Players, David Kimble Wilbanks

Honors Theses

As the human body does work, energy is released in the form of heat. The ability to perform the same action repeatedly and at the same intensity requires energy to be maintained. By preserving energy in sports, a reduction of injuries and an increase in performance duration would most likely be observed. More specifically in sports, for 200 years of baseball history, the pitcher has attempted to keep their arm warm during resting intervals of a game, in belief this would help sustain their level of performance. This study attempted to overturn this view. I hypothesized that by cooling their …

Application Of Ce-Qual-W2 On Tigris River In Iraq, Muhanned Al-Murib

Civil and Environmental Engineering Master's Project Reports

The Tigris River is the eastern member of the two great rivers in Iraq. Two big rivers pass through Iraq, Mesopotamia. Tigris and Euphrates Rivers with their tributaries form a major river system in the Middle East. Four riparian countries, Turkey, Syria, Iran, and Iraq, share the Tigris River basin area and Iraq has the majority of this basin area. The total length of the Tigris is 1850 km from which 1418 km is within Iraq. A study area of 880 km from Mosul dam to Kut barrage is modeled using a water quality CE-QUAL-W2 model. CE-QUAL-W2 is a two-dimensional …

Time-Dependent Mechanical Behavior Of Proton Exchange Membrane Fuel Cell Electrodes, Zongwen Lu, Michael H. Santare, Anette M. Karlsson, F. Colin Busby, Peter Walsh

Mechanical Engineering Faculty Publications

The electrodes used for Proton Exchange Membrane Fuel Cells (PEMFCs) are typically painted or sprayed onto the membrane during manufacturing, making it difficult to directly characterize their mechanical behavior as a stand-alone material. An experimental-numerical hybrid technique is devised to extract the electrode properties from the experimentally measured properties of Nafion^® 211 membrane¹ and a membrane electrode assembly (MEA) based on Nafion^® 211 membrane at various temperatures, humidities, and strain rates. Within the linear regime, the rule-of-mixtures assuming an iso-strain condition is used to calculate the rate-dependent Young's modulus of the electrodes. Beyond the linear regime, reverse …

Implementation And Analysis Of User Adaptive Mobile Video Streaming Using Mpeg-Dash, Abhijith Jagannath

Electrical Engineering Theses - Archive

Modern mobile devices are already matching and surpassing HDTV sets in terms of graphics capabilities. They often feature high density retina screens with 1280X720, 1920X1080 and even higher resolutions. But, the density of the information seen will depend on several factors. The visual perception of the video played on these devices mainly depends on the user, where and how the video is consumed, quality of the video perceived changes when in dark room to that of bright sun light, device held at an arm's distance to device kept away on a table. Streaming high bitrate video to these devices when …

A Formalized Method For State Machine Software Implementation In Smart Microgrid Control Systems, Gregory Kyle Turner

Electrical Engineering Dissertations - Archive

The introduction section begins with a discussion of the electric power grid in general and a specific definition for Smart Grids and Microgrids. These two different but complimentary technologies combine to form the overall Smart Microgrid concept. The control theory for Smart Microgrid applications is broken down into a three-tiered hierarchical scheme in order to simplify the control systems used at each level of the hierarchy. Some background information is presented about current Smart Microgrid projects.A review of recent literature focuses on three areas of interest. The review of control theory focuses mainly on the highest abstract level of the …

Sparse Sensing In Big Data, Junjie Chen

Electrical Engineering Dissertations - Archive

Big data requires exceptional technologies to efficiently process large quantities of data within tolerable elapsed times. While the potential benefits of Big Data are significant, there are still a lot of technical challenges that must be solved to fully realize this potential for Big Data.For processing, transporting and storing large data sets of enormous sizes, data need to be greatly compressed. In this thesis, several sparse sensing algorithms - compressive sensing (CS), co-prime sampling and nested sampling are studied for Big Data, in theory and applications.Error performance bounds of noisy compressive sensing are derived based on information theory and estimation …

Phoresis Of A Solid Particle In Real Fluid, Yuan Ting Wu

Mechanical and Aerospace Engineering Dissertations - Archive

For micro- and nano-scale particles driven by interfacial non-contact forces in fluid, known as phoresis, this dissertation provides a general formulation and a systematic investigation. It starts with an analytical continuum-mechanics formulation that covers various important aspects of an interfacial structure, including viscosity and mass density variations as well as a body force field, in real fluid. It then reduces to specific solutions due to characteristic mechanisms. A closed-form analytical solution to the case of viscosity variation (which manifests itself as Navier's slip boundary condition) is derived. Furthermore, a novel mechanism for thermophoretic mobility driven by near-surface phase transition is …

Models Of Oil Wood Coating Materials Selection According To Technological, Operational, Ecological And Economic Criteria, Larysa Yaremchuk, Tetyana Olyanshyn, Volodymyr Maksymiv, Liliya Stepanivna Hogaboam

Engineering and Technology Management Faculty Publications and Presentations

This article presents the use of system analysis methodology and Graph Theory for validation of the relationships among descriptive factors, which impact the selection of oil materials for wood finishing. Matrix analysis was used to determine the results of the pair wise comparisons of factor weights and optimization of the factor values. Modelling theories have been developed, which allow for construction of models of primary impacts of the factors on oil materials selection in protective and decorative wood coatings creation.

Faults Identification In Three-Phase Induction Motors Using Support Vector Machines, Rama Hammo

Master of Technology Management Plan II Graduate Projects

Induction motor is one of the most important motors used in industrial applications. The operating conditions may sometime lead the machine into different fault situations. The main types of external faults experienced by these motors are over loading, single phasing, unbalanced supply voltage, locked rotor, phase reversal, ground fault, under voltage and over voltage. The machine should be shut down when a fault is experienced to avoid damage and for the safety of the workers. Computer based relays monitor the machine and disconnect it during the faults. The relay logic used to identify these faults requires sophisticated signal processing techniques …

Improving Enrollment In The Construction Management Graduate Program Through Students’ Perspectives, Mouloud Messaoudi

Master of Technology Management Plan II Graduate Projects

Low enrollment and the decrease in graduation and retention rates are challenges facing the growth of the Master’s in Technology Management – Construction Management (MTM-CM) program at BGSU. In addition, the competition between the universities to enroll and retain more in-state, out-of-state, and international students is aggressive. There is a need for a revaluation for the MTM-CM program in order to attract more students in the future. This study is a necessary step to know what the MTM-CM students think about the product delivered to them at BGSU. There was no prior study investigating the satisfaction level of the construction …

Human Cardiovascular Responses To Artificial Gravity Variables: Ground-Based Experimentation For Spaceflight Implementation, Mark Howarth

Theses and Dissertations--Biomedical Engineering

One countermeasure to cardiovascular spaceflight deconditioning being tested is the application of intermittent artificial gravity provided by centripetal acceleration of a human via centrifuge. However, artificial gravity protocols have not been optimized for the cardiovascular system, or any other physiological system for that matter. Before artificial gravity protocols can be optimized for the cardiovascular system, cardiovascular responses to the variables of artificial gravity need to be quantified.

The research presented in this document is intended to determine how the artificial gravity variables, radius (gravity gradient) and lower limb exercise, affect cardiovascular responses during centrifugation. Net fluid (blood) shifts between body …

Moving Obstacle Detection And Avoidance For Unmanned Ground Vehicle, Gangadhar Rajashekaraiah

Mechanical and Aerospace Engineering Theses - Archive

This thesis presents the development and implementation of an autonomous obstacle avoidance algorithm for UGV (Unmanned Ground Vehicle). The research improves the prior work by enhancing the obstacle avoidance capability to handle moving obstacle as well as stationary obstacles. A mathematical representation of the area of operation with obstacles is formulated by PTEM (Probabilistic Threat Exposure Map). The PTEM quantifies the risk in being at a position in an area with different types of threat. Threat in this context means UGV getting close to or running into stationary and moving obstacles. A LRF (Laser Range Finder) sensor mounted on the …

Computational Flow Analysis Of A Flapping Micro-Flyer Wing For Cycle-Averaged Force Production, Nitesh Rajendra Rajput

Mechanical and Aerospace Engineering Theses - Archive

Human engineers have been trying long to mimic creations of nature for their own benefits. One such area of interest is the insect based micro flapping wing flyers for their wide employment in commercial as well as military applications. These micro air vehicles (MAVs) are capable of performing acts that can be too dangerous for humans to perform, such as tactical reconnaissance in a combat zone. The maneuverability required of these MAVs call for a careful design and thorough study of their aerodynamic performance. This research goal is to provide an estimation of the forces generated during the flapping motion …