Electrical Engineering Industrial & Systems Engineering ...catcher.sandiego.edu/items/usdengr/12-13Updated USD Faculty Reseach...Electrical Engineering Industrial & Systems Engineering

Faculty Research Profiles2012-13

Electrical EngineeringIndustrial & Systems Engineering

Mechanical Engineering

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Faculty and Their Research Interests

Electrical Engineering..........................................................................................................................2

Industrial & Systems Engineering......................................................................................................3

Mechanical Engineering ......................................................................................................................4

Recent Faculty Research Projects

Electrical Engineering..........................................................................................................................5

Engineering Education ........................................................................................................................8

Industrial & Systems Engineering......................................................................................................9

Mechanical Engineering ....................................................................................................................11

Mission StatementUSD Engineering is distinguished by student-centered education that emphasizesmodern engineering skills and development of the whole person. We arededicated to innovative teaching, meaningful scholarship, and compassionateservice.

UMessage from the Director

I am proud to present this report that introduces our well qualified facultyand their meaningful scholarship by providing an overview of the researchtopics currently being pursued in Engineering at USD. Engineeringresearch lays the groundwork for the innovations of tomorrow that canimprove the lives and the livelihood of many.

Faculty areas of research include advances technology and processes inwide array of topics in Electrical, Industrial & Systems, and MechanicalEngineering with applications to healthcare & medicine,telecommunications, manufacturing, aerospace, and more. Scholarship inengineering education helps to address the engineering workforce crisis byproviding innovations in teaching and learning that help students succeedin the demanding preparation needed to become the engineers oftomorrow.

-Kathleen A. Kramer

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EElleeccttrriiccaall EEnnggiinneeeerriinngg FFaaccuullttyyErnest M. Kim, P.E.Ph.D. New Mexico State UniversityRadio Frequency Design, Optical Transmission Systems,Embedded Systems, Analog Circuits, RF circuits,Optoelectronic circuits,Fiber Optics, Cable Television

Kathleen A. KramerPh.D. California Institute of Technology

Sensor Data Fusion, Kalman Filters, Neural Networks,Evidence Accrual, System Identification, Fuzzy Logic

Susan M. LordPh.D. Stanford UniversityEngineering Education, Persistence of Women inEngineering, Lifelong Learning, Feminist and LiberativePedagogies, Cooperative Learning, Service learning,Optoelectronic Materials and Devices

Mikaya L.D. LumoriPh.D. University of ArizonaNonlinear System Identification Techniques,Electromagnetic Hyperthermia

Michael Steven MorsePh.D. Clemson UniversityBiological Effects of Electricity, Diffuse Electrical Injury,Modeling of Current Pathways, Carpal Tunnel Syndrome,Electrical Injury and Safety,Electromechanical Product Failure

Thomas F. SchubertPh.D. University of California, IrvineFourier Optics, Wave Propagation,Analog Electronics, Communication Systems,Engineering Education.


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IInndduussttrriiaall && SSyysstteemmss EEnnggiinneeeerriinngg FFaaccuullttyyBradley ChasePh.D. University of LouisvilleHuman Factors Engineering, Ergonomics,Electrophysiological Measures and CognitivePerformance, Environmental Stress and Performance,Healthcare Performance Improvement, OccupationalSafety, Work Design, and Application of IndustrialEngineering Techniques in the Service Sector

Rick T. OlsonPh.D. University of Illinois at Urbana-Champaign

Operations Research, Heuristic Optimization,Scheduling, Health Systems,

Decision Support Systems

Leonard A. PerryPh.D. Arizona State UniversityDesign of Experiments (DOE), Six Sigma,Quality, Process Improvement,Statistical Process Control (SPC)

Truc T. NgoPh. D. Georgia Institute of Technology

Research Areas: Biodegradable Polymers and Composites,Material Processing with Supercritical Carbon Dioxide


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MMeecchhaanniiccaall EEnnggiinneeeerriinngg FFaaccuullttyyMing Z. HuangPh. D. Ohio State UniversityMechanical Design, CAD/CAE,Kinematics and Dynamics of Machinery, Robotics,Manufacturing Automation, Engineering Pedagogies

Frank G. JacobitzPh.D. University of California, San Diego

Fluid Mechanics and Turbulence, Geophysical Flow, Bio-Fluid Mechanics, Microcirculation, Hemo-Dialysis,

Virus Removal, Student Learning

James G. KohlPh.D. Rensselaer Polytechnic Institute, NYCoating Characterization, Foul Release Coatings,Mechanical Properties of Polymers, Adhesion, Tribology

David MalickyPh. D. University of Michigan

Biomechanics, Soft-tissue mechanics, Finite ElementAnalysis, Silicone Coatings, Guitar Engineering and

Acoustic, Experimental Methods, Pedagogy,Matthew McGarryPh. D. University of VermontDesign of PEM fuel cells,Heat Transfer Enhancement,Bio-Fluid Mechanics, Fluid Mechanics of the systemic circulatorysystem

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Adaptive Neural Network Target Tracking (K. A. Kramer)The concept of target tracking, a part of Level 1 data fusion, isto combine measures from various sensors to form a coherentpicture of the scene. It has become an important field ofresearch as its applications in robotics, space systems, andmissile defense have grown. Target tracking systems areusually based on estimation techniques such as the extendedKalman filter (EKF) that use sensor measurements over timeand a model of the kinematics of the target. Such trackingsystems, although widely used, have difficulty when the targetbeing tracked undergoes a maneuver. The neural extendedKalman filter (NEKF) is an adaptive EKF that uses functionsapproximation to learn the error between the true targetdynamics and the mathematical model used in the predictionstates of the EKF. The NEKF is the focus of several researchefforts to improve and analyze tracking performance, performsystem identification, and assist in improving controlperformance. The NEKF uses an artificial neural network thatdoes not use a priori training sets common to most neuralnetwork techniques as a function approximation technique.Instead, it adapts and trains as the target is moving using thesame residuals as the Kalman filter of the track estimation.

Diffuse Electrical Injury (DEI) (M. S. Morse)Tissue damage from electrical contact has historically beenthought to arise from resistive heating of tissues along thecurrent pathway. A more modern view has accepted that tissuedamage can result from cellular rupture (electroporation)induced by the presence of an electric field. In rare electricalcontacts, diffuse symptomatology arises that does not fit wellwithin either model. Such disproportionate, remote electricalinjury is most notable when the contact voltage is low (120and 240 V). Symptoms occur, absent diagnostic evidence,which defy explanation as organic injury. Research has beenundertaken that statistically suggests that there is a commonsymptomatology, called Diffuse Electrical Injury (DEI) that isneither linked to voltage nor loss of consciousness at the timeof contact.

Semiconductor Laser Beam Shaping using Magnetic Fields(E. M. Kim) Preliminary tests on shaping the radiation patternof laser diodes using magnetic fields have been completed.Radiation patterns at both below and above threshold arebeing studied. Dependence on laser structure is beingconsidered. Potential applications include beam shaping andbeam steering of the exit radiation from semiconductor diodes.

Eco-Responsible Product Design (E. M. Kim)Over 2 billion batteries end up in landfills yearly. Unlikeglass, paper, and plastic, which fill up landfills, but arerelatively benign, batteries are filled with reactive chemicals.

Eco-responsible electrical designs are being developedspecifically for the toy industry.

Faraday Effect Charging Cycle

Electromagnetic Hyperthermia (M. L. D. Lumori)Research Focus: Gaussian Beam Modeling of Field Sources.There are several types of electromagnetic radiating antennasused for localized or regional hyperthermic treatment oftumors. These are based on waveguiding structures that maybe used individually or as phased arrays. However, theirperformance must be ascertained by application of 3-Dnumerical models to the electric field integral-equation(EFIE), the magnetic field integral-equation (MFIE), etc., tosimulate specific absorption rates (SAR) in a tumor. GaussianBeam modeling of the field sources improves SARsimulations considerably. The Gaussian Beam Model (GBM)is the exact solution to the Schrödinger-type equation which isan approximation to the scalar wave equation.

Embedded Control of Optoelectronic Devices (E. M. Kim)An EDFA can be used to directly amplify optical signals,avoiding signal conversion to-from electrical, and amicroprocessor can be programmed to control and monitorthis amplification. The microprocessor makes digital dataavailable to an external computer via standard serial link, andit may also receive external digital commands via the samepath. A principal control function of the microprocessor is todetermine the current of either laser, independently, by settingor varying a reference voltage to which the backface controlphotodiode output of the laser is compared. The systemsinvolved to control vary with either one or two pump lasersand supporting analog circuitry present, and in the variousnumbers of monitor detectors and associated analog circuitry.Such differing configurations require different designs for theembedded control system.

Finite Element Analysis of the Internal Current Pathway(M. S. Morse)An active area of research focuses on trying to distinguish thereal current path from the theoretical path during an electricalcontact. A variety of mathematical techniques, including theFinite Element Method (FEM), have been applied to this


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problem to determine current distribution within the humanbody. Specific efforts to date have included evaluating currentdistribution in the carpal tunnel region with the specific intentof explaining post-electrical-contact carpal tunnel syndrome(CTS). CTS has been diagnosed in as many as 10% of thehand-involved electrical contacts; such a diagnosis typicallyindicates median nerve compression, which would not beconsistent with the known apparatus of electrical injury. UsingFEM, current density has been evaluated in the carpal tunnelregion during an electrical contact. Results of research haveindicated that while the majority of current does not transversethe nerve tissue, the current density is significantly elevated inthe nerves as they traverse the carpal tunnel region. Such alocalized current elevation could cause nerve damage whichwould masquerade as CTS when diagnostically tested.

Finite Element Model of Human Tissue

Persistence of Women in Engineering (S. M. Lord)“The Effect of Climate and Pedagogy on Persistence: ALongitudinal Study of Women in Undergraduate EngineeringPrograms,” capitalizes on a unique opportunity to conduct alongitudinal, multi-institutional, and multivariate studydetermining how climate and pedagogy affect the persistenceof women in undergraduate engineering programs to an extentnever before possible. We focus on the nine partnerinstitutions that comprised the NSF-funded SoutheasternUniversity and College Coalition for Engineering Education(SUCCEED) Coalition and account for 1/12 of theengineering bachelor’s degrees awarded from 1987 to 2004. Akey benefit of the choice of this population is three keyoverlapping sources of data: 1) the Multiple-InstitutionDatabase for Investigating Engineering LongitudinalDevelopment (MIDFIELD), 2) climate surveys and 3)teaching practices surveys. We are conducting new analyseson this existing data as well as new studies focusing on ourresearch questions. Such a triangulated approach provides apowerful historical context to explain changes and successes

in persistence. This project is funded by the National ScienceFoundation (NSF) Research on Gender in Science andEngineering (GSE) program and is in collaboration with Dr.M. Camacho in Sociology at USD and Drs. M. Ohland and M.Wasburn at Purdue University.

Nonlinear System Identification Techniques(M. L. D. Lumori)Research Focus: Measurement, Modeling and Identification ofDynamic Systems. A typical nonlinear complex system isoften decomposed into subsystems that are then characterizedusing dedicated tools. Experimental data, sometimes obtainedfrom poor measurement/simulation sources, are used by thedesigner to extract a wide variety of models that must meetspecific requirements. Since most systems are nonlinear innature, the best linear approximation (BLA) is often sought togive an insight into the dynamics of a nonlinear system.System Identification is via use of the appropriate estimators(e.g. least squares, weighted least squares, Maximumlikelihood, or Bayes estimators) for each system andassociated environment (e.g. errors on the input and outputdata).

Analog Circuit Design (E. M. Kim)Detailed investigation of Miller’s Theorem as it applies totransistor amplifier design has yielded results that are counterto the Miller effect pole that is used in many electronics circuittextbooks as the only pole of significance. In fact, carefulapplication of Miller’s theorem provides pole locations thataccurately represent true circuit behavior.

Miller Effect Model of a BJT Amplifier using SPICE CircuiitParameters

Sensor Data Fusion (K. A. Kramer)Multi-sensor data fusion is the process of combining,comparing and interpreting information across a number ofdisparate sensors. Often, in a sensor fusion environment, thesensors are of a wide variety providing a diverse set ofmeasurement types. Level 1 fusion identifies and tracksentities, while Level 2 fusion, also known has SituationalAssessment, develops and interprets relationships among theentities, including such concepts as group kinematics, group


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formation, and group composition. Research is beingundertaken to apply a variety of techniques to these complexproblems including:

For classification, methods to better interpretmeasurements of from various sensors that havedifferent degrees and types of uncertainty, accruedisparate evidence over time, and apply fuzzy logic.

For L1 association, application of a fuzzy-logic basedmethod that emulates the chi-squared metric for bothGaussian and non-Gaussian measurements for dataassociation.

For group composition, Markov chain methods thatmake use of multiple composition hypotheses andincorporate terrain, group dispersion, and sensorcapabilities into transition probabilities.

Multi-Sensor Data Fusion – information from differentsensors fused together to provide assessment of

situation.

Evidence Accrual (K.A. Kramer)In many fusion problems observations provide indirect, ratherthan direct, evidence. In such cases, the measurements affectthe evidence level through a functional relationship, such asspeed being measured through the functional relationshipbetween it and position observations over time. A generalevidence accrual system that incorporates indirectobservations into the evidence generation is being developed.The technique, based on the concepts of first-order andreduced-order observer theory, can incorporate bothobservation quality and level of doctrine understanding in theuncertainty measure of the evidence. The technique uses anetwork structure with links and propagation of evidence, but,unlike a Bayesian taxonomy, it does not rely upon the strictprobabilistic underpinnings. The technique is based upon aLevel 1 fusion target classification evidence accrual algorithmand uses a fuzzy Kalman filter to inject new evidence into thenodes of interest to modify the level of evidence. Using thefuzzy Kalman filter allows for the level of evidence toincorporate an uncertainty or quality measure into the report.

Embedded Control of Magnetics Circuits (E.M.Kim)Magnetics circuits can be energized in sequence usingembedded controllers. User interfaces are employed thatallows for sequence modifications in pattern and time.Current applications include the development of a toy.

Embedded Controller for Magnetics Circuits

Electrical Machines and Energy Conversion for Lower-Division Engineering Students(T.F. Schubert, F.G. Jacobitz, E.M. Kim)In order to meet changing curricular and societal needs as wellas a resurgence in interest concerning basic electric machinesand their control, a number of electrical machine laboratoryexperiences for sophomore students are under development.These experiences are unusual in that they are placed early inthe curriculum and utilize subfractional-horsepower (< 5 W)electrical motors. Motor topics include modeling of electricmotors, predicting motor performance, and experimentallyobtaining relevant motor performance constants. Theefficiency of converting electrical energy into mechanicalenergy is measured with a unique and simple small-scaledynamometer developed by the team comprised of anoptoswitch-based tachometer and torque measurementsobtained with a slipping-clothespin lever arm and a linearspring scale.

While subfractional-horsepower DC motors can commonly befound in toy applications, subfractional-horsepower ACmotors are not as obviously located. However, the duality ofmotors and generators leads to finding synchronous ACmachines as generators in many low-power “green”applications. Use of these AC machines as motors requiresthe development of low power – low voltage, three-phasepower sources. Currently under development is one suchthree-phase power synthesizers based on: up-down digitalcounters, D/A conversion and wave-shaping. Such stand-alone, low-power, three-phase sources provide an added bonusof facilitating the study of three-phase systems at very safevoltages and currents.


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Initial assessments of student learning and confidence inapplying the concepts relevant to electrical machines andenergy conversion have shown significant increases in eachcategory.

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Enhancing Student Learning (S. M. Lord)Current research areas in engineering education includeinvestigating a range of strategies for enhancing studentlearning including cooperative learning, hands-on laboratories,and using Tablet PCs. The researcher is a leader in the fieldactively involved with the Educational Research Methodsdivision of ASEE and the Education Society (EdSoc) of IEEE.Leadership positions include General co-Chair of the 2006Frontiers in Education Conference, IEEE EdSoc President for2009 and 2010, and Guest Co-Editor of Special issue ofInternational Journal of Engineering Education. Another areaof interest is an investigation of the potential benefits offeminist pedagogy for engineering education, a joint effortwhich received the Helen Plants Award in 2004.

Lifelong Learning (S. M. Lord)“Role of faculty in supporting lifelong learning: Aninvestigation of self-directed learning environments inengineering undergraduate classrooms” examines how facultychoices in the classroom influence students’ lifelong learningskills. Lifelong learning is a critical skill for engineeringgraduates. While the literature on self-directed learning offersinsight into how to develop lifelong learning skills,engineering educators have focused more on assessing lifelonglearning than on understanding how instructors can foster suchskills. With a project team from engineering and education atfour different institutions, we are well positioned to investigatea variety of learning environments making results useful to thewider engineering education community. This project isfunded by the National Science Foundation (NSF) ECCInnovations in Engineering Education, Curriculum, andInfrastructure (IEECI) program and is in collaboration withDrs. M. Prince, C. Stefanou, K. Nottis of Bucknell University,Dr. J. Stolk of Olin University, and Dr. J. Chen of CalPolySan Luis Obispo.

Engineering Mathematics Education (S. M. Lord, R. T.Olson)The inability of incoming students to successfully advancepast the traditional freshman calculus sequence is a primarycause of attrition in engineering programs across the country.Engineering faculty at Wright State University have developeda new paradigm that introduces students to all of the essentialmathematics needed to succeed in the first two years of

engineering. In the one quarter class, students meet for sixhours each week in lecture and laboratory settings. Thismodel has been shown to improve retention at schools wherethe entering students are not well-prepared for calculus.USD’s contribution to the project is to assess the mathematicsdifficulties of early engineers at a university where moststudents are calculus-ready and to determine whether two one-unit elective engineering mathematics classes will alsoimprove improve student retention. This project is funded bythe National Science Foundation (NSF) as part of a DUE -CCLI Phase III implementation project that is being led by Dr.N. Klingbeil of Wright State University.

Assessment of Student Perceptions of Multiple TextbookEditions Use to Reduce Cost to Students (F. G. Jacobitz, T.F. Schubert, E. M. Kim)Motivated by a potential reduction in cost to students, theconcurrent use of multiple textbook editions is studied inengineering courses. The student learning environment isassessed and evaluated for a potential negative impact. Thefundamental hypothesis of this study is concurrent use ofmultiple textbook editions significantly reduces student costwithout negative impact on the student learning environment.Students are asked to complete a three part survey assessingvarious aspects of using multiple textbook editions as well astheir textbook purchasing and return habits. Overall the choiceof multiple textbook editions is welcomed by the students.This survey results show that the cost for students was reducedappreciably. A majority of students report no negative impactof their learning, thought that instruction is edition-neutral,and generally appreciate the choice between textbook editions.

Studies of the Engineering Design Process in NoviceDesigners (T. F. Schubert, F. G. Jacobitz, M. S. Morse, T. T.Ngo, E. M. Kim)The engineering design process is a central theme in theengineering profession and essentially all engineeringcurricula. There are currently two studies underway by theteam: (1) to investigate if a single lecture on engineeringdesign and a short laboratory exercise early in the semestercan help develop student knowledge about and studentconfidence in applying the engineering design process, and (2)to assess the impact of the presence of a prototype exemplaron novice designers prior to asking those designers to engagein an engineering design exercise. Initial studies have shownthat a short presentation on the engineering design processfollowed by a simple laboratory exercise is a meaningfultechnique to teach the basics of engineering design. Studentknowledge of and confidence in applying the engineeringdesign process increased upon completion of a simple designexercise as evidenced in the assessment study. Analysis ofdata concerning whether the presence of a prototype exemplarresults in significant “design fixation” in a multi-stage designprocess is currently underway.


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Compact International Experiences (T. F. Schubert, F. G.Jacobitz)The efficacy of delivering upper-division engineeringelectives as study-abroad, short-term courses is under studyprimarily through the experiences gained by considering twodistinct three-semester-unit courses in a three-week time framein France and Australia, respectively. Initial results show thatthe Compact International Experience course format hasproved to be an effective format for the delivery of two seniorelective engineering courses. Despite the short timeframe ofdelivery, all evidence collected (student course evaluations,instructor observations and course grades, student weeklyreflection papers, and an assessment of the internationalexperience) point to an educational experience equivalent incourse content and depth of coverage to that of typicalsemester long courses delivered at the home institutioncoupled with an enriching international experience. Thecourses will be repeated in January 2013 and assessment ofthe format will continue.

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Cognitive Performance under Stress (B. Chase)The environment in which we work can place manyconstraints upon our ability to perform both physical andcognitive tasks. For nearly five decades researchers haveinvestigated thermal stress effects on human cognitiveperformance. Although much data have been collected,relatively little consensus was reached with regard to either thetrue nature of thermal stress effects, or an existing mechanismfor predicting human performance under thermal stress.Several factors have likely contributed to the substantialvariation in the findings of previous thermal stressinvestigations. Research in this area attempts to quantifycognitive deficits due to thermal stress, develop interventionsand inform both task redesign and policy decisions.

Design of Experiments (L. A. Perry)Experimental design is a systematic approach to planning andanalyzing experiments so that meaningful results can beobtained in an efficient and timely manner. Design ofExperiments (DOE) can be used to reduce productdevelopment time or improve a manufacturing or serviceprocess. In design of experiments, the experimenter isconcerned with processes of planning and conducting anexperiment; once the experiment is conducted, the resultingdata can be analyzed so that legitimate, objective conclusionscan be made. The application of DOEs in the engineeringdiscipline has become a critical tool for developing andimproving manufacturing processes and systems as well as theproduct development cycle. If a process exists, DOEs can beused to improve it. Currently, experimental design methods

are being used to improve yields and reduce variability inproducts in local biotech, pharmaceutical, and telecomcompanies.

Electrophysiological Measures of Cognitive Performance(B. Chase)Research in this area is based on the understanding thatnumerous cognitive processes are ongoing in parallel. Thereare externally measurable reflections of these processesavailable to us including: measurable movement behaviors(button presses), recordable brain activity measures (such asthe electroencephalogram (EEG)) and eye movementbehavior. While eye movement behavior is perhaps the mostinformation impoverished of these measures, it is the mostunobtrusive measure that can provide millisecond-to-millisecond reflections of underlying cognitive processes.While there are tasks that are obviously reflected in eyemovement activity (e.g. visual searching paradigms), nearlyall cognitive processes have at least some indirect influence oneye movement behavior. The eye movement behaviors can beanalyzed in terms of the neuro-dynamics, the system-widebehavior of the brain in action. This capability is largelybased on advanced EEG recording and analysis techniques.The goal is to elucidate the neuro-dynamic behaviors in eyemovement activity as it relates to cognitive processes. Withinput concerning operator state available to an adaptivesystem, the task itself could be modified to account foroperator fatigue, attentional state, and other performancecharacteristics of interest.

Healthcare Operations (B. Chase, L. A. Perry)Several projects have been undertaken in the area ofmanagement engineering where Industrial Engineeringconcepts and techniques are applied within the health carearena. Projects include hospital staffing, discrete eventsimulation, lean and six sigma, supply chain management,reduction of wait times, operational performanceimprovement, electronic medical record implementation,occupational safety, and work and workstation design.

Six-Sigma (L. A. Perry)Six-Sigma is a systematic, data-driven quality improvementmethodology that has proven quite effective in recent years.Specifically, it is an approach by which a cohesive collectionof quality improvement tools is utilized to reduce processvariation. More broadly, it is a managerial and culturaldirective toward achieving near-perfect quality, only 3.4defects per million opportunities (DPMO). Six-Sigma isbecoming commonplace in the manufacturing sector due tothe benefits that are undeniable, but still there exists anelement of skepticism that prevents its widespread use in theservice sector. Continuous improvement initiatives still haveplenty of growth potential in health care, financial, anddefense industries as Six-Sigma becomes more visible andcost savings are identified.


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Processing Behaviors of Thin-Film Pentacene andBenzene-1,4-Diboronic Acid inSupercritical Carbon Dioxide (T. T. Ngo, J. Keegan–USDUndergraduate, R. D. George–SPAWAR)This research investigates the feasibility of using supercriticalcarbon dioxide (scCO2) as a green solvent for processingorganic thin film semiconductor, such as pentacene, and apotential molecular modifier for use in electronic deviceapplications. Benzene-1,4-diboronic acid (BDBA) wasselected as a molecular modifier in this work due to itselectron deficient nature, which can potentially enhancepentacene's physical, chemical or electronic properties bychanging its structure in the solid state. In this study, thesolubilities of BDBA and pentacene in scCO2 are measured asindividual compounds and as co-solutes, at 313 K, usingultraviolet (UV) spectroscopy. Methanol co-solvent effects onsolubility have also been characterized for each compound.The results show that BDBA is insoluble in pure scCO2 up to1.82×107 Pa. However, with a small amount of methanoladded to the mixture, BDBA becomes soluble in solution witha solubility of 3.81×10−4 mol/l at 9.00×106-Pa-pressure. Incontrast, pentacene is only soluble in scCO2 at pressures above1.10×107 Pa, and its solubility is decreased upon addition ofmethanol due to the non-polar nature of pentacene. When apentacene thin film is treated with BDBA in scCO2/methanolsolution, BDBA sorption is observed at pressures as low as8.80×106 Pa. Based on these results, it is concluded thattreatment of pentacene thin films in scCO2 is a promisingapproach that can be optimized for BDBA and other similarmolecular modifiers, to produce multi-component organic thinfilm devices.

Green Surfboards: Investigation of ProductBiodegradability at End of Life (T. T. Ngo, J. A. Hall–USDUndergraduate, J. G. Kohl, L. A. Perry)As the world becomes more environmentally conscious,companies find ways to make products and manufacturingprocesses greener. This work examines an innovativesurfboard product that uses bio-based fiber-reinforcedpolymers to address product disposal issues and to lower thetoxicity associated with some of its components andmanufacturing processes. The goal of this work is tocharacterize the biodegradability of the "green" surfboards atend of life, focusing on the fiber-reinforced compositelaminate covering the surfboard and the core of the board.Different laminate types, with various combinations of resins(polyester, epoxy, and a bio-resin) and reinforcing fibers(fiberglass, organic hemp, and organic cotton), were tested.Polystyrene core was compared with the green alternativebalsa wood core. Degree and rate of biodegradability ofmaterials were evaluated by measuring weight change andmaterial hardness over 56 days under controlled compostingconditions. The results suggest that the resin component in thecomposite laminate is the key factor that controls the rate ofbiodegradation of the material. In addition, different resins

exhibit different degradation mechanisms, depending on thechemical and biological nature of the materials.

Effects of Plant-Fibers and a Tertiary Oil Phase on theCompostability of Polyester- and Epoxy-Based Fiber-Reinforced Composites (T.T. Ngo, C.A. Lambert-USDUndergraduate, L. Benz, S. Morrison, M. Chau-USDUndergraduate)This research investigates the effects of different plant-fiberson the compostability of polyester- and epoxy-based fiber-reinforced composites. Natural fibers, such as hemp, bambooand cotton, are used as alternatives to fiberglass. A linseed oil-based resin is also used as an alternative to polyester andepoxy polymer matrix. In addition, a tertiary oil phase (eitherlinseed oil or pine oil) is introduced into the polyester andepoxy matrix to improve the compostability and ductility ofthe material. Compostability experiment is performed in anaerobic environment with compost solution at 58°C for over49 days. The morphology of material surface and cross-sectionis examined using scanning electron microscopy (SEM), anddissolvable by-products in composting solution are analyzedusing liquid chromatography-mass spectroscopy (LCMS)method. The solid composites after composting treatment arealso characterized using thermal gravimetric analysis (TGA)and differential scanning calorimetry (DSC) techniques. Rateof biodegradation and material degradation mechanisms arestudied and compared among different sample types.

Characterization of the Mechanical Properties of Bio-Based Fiber-Reinforced Composites (T.T. Ngo, C.A.Lambert-USD Undergraduate, J.G. Kohl, M. Bliznyuk-USDUndergraduate)This research focuses on the development and characterizationof several new fiber-reinforced bio-composites. In the newcomposites, the traditional fiberglass is replaced with naturalfibers such as hemp, bamboo and cotton. Also, the traditionalpolyester and epoxy resins are either totally replaced bylinseed oil-based (UVL) resin, or mixed with linseed oil orpine oil to improve their compostability at end of use.Composite samples are prepared using the hand lay-upmethod. UVL-based samples were proven to be the easiestones to prepare with fastest production time, ease of handlingand most consistent in surface thickness and uniformity. Onthe other hand, surface uniformity becomes an issue for non-UVL samples when the mixed oil content is more than 10% byweight. Surface hardness and the tensile properties of thematerials were measured to determine the effects of plant-fibers and a tertiary oil phase on the polymer matrix.


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Pedagogical Applications of Time CompressionTechnologies (M. Z. Huang)Time compression technologies refer to the modern industrypractices that integrate rapid prototyping with modeling,analysis, and simulation techniques, such as computer-aideddesign (CAD) and finite element analysis (FEA), for productdesign and development. This research aims to explore novelways of incorporating these practices into existingundergraduate engineering curriculum. Application studieswill be conducted using the CAD, FEA and rapid prototypingtools such as Pro/E and Z-Corp 3D Printer available at USD.

Performance-based Dimension Synthesis of RCM- and SL-Type Mechanisms (M. Z. Huang)Special mechanisms, such as the remote center of motion(RCM) and the straight-line (SL) types, have seen increasingapplications in medical automation and surgical procedures. Inaddition to their specific kinematic properties, otherperformance characteristics, such as stiffness and velocity,need to be considered in order to meet the rigorousrequirements of precision and safety in the medical arena.This research aims to develop a performance-based dimensionsynthesis methodology using the RCM and SL-typemechanisms as the underlying structures. Works in this areainclude a recent study on dimension synthesis for thePeaucellier SL-mechanism and an ongoing project ondevelopment of an RCM-based mechanism for dental surgicalapplications.

Design Optimization of Hybrid Series-Parallel Robots (M.Z. Huang)Robotic mechanisms traditionally are either of ‘serial’ or‘parallel’ configurations. While a serial robot has largerworkspace, it lacks stiffness inherently and thus has poor loadcarrying capability. A parallel robot, on the other hand,exhibits just the opposite to its serial counterparts. Roboticmechanisms with unconventional, hybrid series-parallelconfigurations could provide a natural compromise. Thisresearch addresses three areas: 1) coordination theory, whichis the level of control where inputs to the actuators aredetermined given the geometric structure of a mechanism, 2)workspace characteristics, which encompass the study andcharacterization of the robot’s reachability (see figure) as wellas dexterity, and 3) task planning and simulation, whichinclude the generation of trajectory, dynamic simulation andvisualization. The work aims to develop a CAD/CAEenvironment whereby the kinematics, dynamics andworkspace characteristics of hybrid mechanisms of differentgeometric structures may be evaluated for design anddevelopment of such systems.

Figure: Complete pose workspace for a 3-DoF revolute-jointed planar parallel robot. The range of rotation is shown ina color spectrum from +180 (in red on top) to -180 (in blue atthe bottom) degrees.

Pedagogical Integration of Design Innovation Tools (M. Z.Huang)Many of the problem-solving and design tools, such as TRIZ,Axiomatic Design, Exact Constraint Design, Kepner-TregoeMethod, have been well adopted in industries and consideredimportant for innovations for years. However, their roles andinclusions in regular engineering curriculum still seem to berelatively obscure and slow. This pedagogical researchinitiative aims to 1) explore effective ways of integrating theminto the engineering curriculum, and 2) develop appropriatepedagogical strategies and materials using, for examples,application modules and case studies.

Biomechanics (D. Malicky)

Patients with diabetes are susceptible to a number of foot

lesions, which often leads to loss of tissue or appendage.

Ulcers on the plantar surface of the great toe are the most

commonly seen problem in patients with diabetic neuropathy.

Onychocryptosis (ingrown toenail) is also common in these

patients and the general population. The aim of this study is to

develop an anatomical finite element model of the hallux

(great toe) to elucidate its internal mechanical response to

external loads. Anatomical slice images from the NIH Visible

Human project were digitized and reconstructed, creating an

anatomical 3D Pro/Engineer solid model of all tissues. The

material properties of the skin, nail, bulk tissue, and bone are

incorporated in a large-deformation analysis to elucidate the

contributing factors toward peak skin stresses on the plantar

surface, intradermal tissue, and the lateral nail fold. Various


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treatment options are examined for their relative efficacy at

reducing peak stresses across the 3 regions.

Cross-section of toe showing vertical displacement field of

tissue in response to plantar pressure loading from elastic

footbed.

Durability of Elastomer Coatings (J. G. Kohl)Silicone is currently being investigated for use as foul-releasecoatings. Silicone when used as a coating has been known tosuffer from both poor adhesion and poor durability. Efforts arebeing directed at improving the toughness and adhesion ofthese coatings without reducing their foul release behavior.One method of evaluating the toughness and adhesion of thesecoatings is by means of a scratch tester. It was found in earlierwork that the failure mode and durability of the coatingdepended on coating thickness. Current work is beingperformed in the identification and modeling of materialparameters that contribute to the toughness and adhesion ofthese coatings. Nanoindentation techniques are used todetermine the parameters under investigation.J.G. Kohl, N.X. Randall, N. Schwarzer, T.T. Ngo, J.M.Shockley, and R.P. Nair, "An Investigation of Scratch Testingof Silicone Elastomer Coatings with a Thickness Gradient,"Journal of Applied Polymer Science, Vol. 124, May 2012, pp.2978–2986.

Silicone Coatings (D. Malicky)Silicone coatings are widely used on ship’s hulls to ease therelease of barnacles, improving fuel efficiency. But, theinterface stresses due to pull-off and shear forces are not wellunderstood. With Dr. Kohl, this study develops a finiteelement model of a variable thickness silicone coating and

pseudo-barnacle, examining the location andmagnitude of peak interface stress under a widerange of silicone thicknesses. Specialized mesh refinementtechniques have been developed to accurately characterize thestresses concentration near the edge of the pseudo-barnacle,which cannot be simulated by conventional elasto-plastic

techniques. Results indicate a complex relationship betweenpeak stress magnitude, location, and silicone thickness.

Cross-section of silicone coating with pseudo-barnacle under

pull-off stress, showing stress distribution.

Acoustic Guitars (D. Malicky)Through trial-and-error, keen sensitivity, and some objectivemethods, individual luthiers and guitar factories havedeveloped the design, materials, and manufacturing processesof the steel-string acoustic guitar to a relatively refined level.Sound quality variances are thought to be caused by variablewood properties but this has not been quantitativelydemonstrated. The scientific relationship of the guitar’ssubjective sound qualities to material and componentproperties (stiffness, density, thickness, damping, resonance,etc) is poorly understood. The aim of this pilot study is toexamine correlations among material properties, componentproperties, acoustic resonances, and the subjective soundqualities of the acoustic guitar. Each top’s density, stiffnesses,damping, and tap tone were assessed. Tops were randomlyassigned to students, who then constructed their guitars in theMENG 351 lab. Sound quality was assessed and FFT analysisshowed the resonant frequencies of the air, top, and backmodes. Regression analysis between input and outputvariables indicate the top and back frequencies were stronglycorrelated to air frequency, and that qualitative luthiermethods do correlate to the finished guitar’s tone.

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mpulse frequency response of sample guitar body, showing

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Foul Release Coatings (J. G. Kohl)It has been shown that the foul release properties of siliconeelastomer coatings are related to not only the work of adhesionbut also to bulk modulus and thickness. Thick and thincoatings have different release behavior. There is a thicknessdependence for thin coatings whereas beyond a certainthickness the release properties are independent of thickness.This transition in behavior is currently being investigated.J.G. Kohl, D.M. Malicky, A.M. Jones, S.L. McGee, and C.Bonilla, "Removal of Pseudobarnacles (Epoxy) from SiliconeCoatings with a Thickness Gradient Due to an AppliedTransverse Force," Progress in Organic Coatings, Vol. 71,July 2011, pp. 310-313.

Microcirculation (F. G. Jacobitz)The microcirculation in rat skeletal muscle and skeletalmuscle fascia is investigated. Tissue samples are preparedsuch that the micro-vessel network pattern can bereconstructed and studied. Those networks consist of arterialvessels supplying blood, capillaries for the exchange ofnutrients and metabolites with the surrounding tissue, andvenule vessels collecting blood. The vessel topology is used incomputer simulations of the flow in the network that providecomprehensive information about pressure and velocitydistributions in the network that is not available fromexperiments. The simulations take passive and active vesselproperties into account. The non-Newtonian properties ofblood are modeled as an apparent viscosity based on previousexperimental data.

Micro-Vessel Network

Turbulence in Stratified Rotating Shear Flows (F. G.Jacobitz)The evolution of turbulence and turbulent mixing isinvestigated in stably stratified rotating shear flows usingdirect numerical simulations. Such flows are important inmany engineering applications as well as in flows in theatmosphere and oceans. An understanding of the competingeffects of shear, rotation, and stratification is required in orderto quantify the transport of momentum, heat, pollutant, and

nutrients in such flows. Most recently, wavelet-bases scale-dependent geometrical statistics have been employed toelucidate properties of turbulence structure and dynamics. Thedirect numerical simulations resolve all dynamically importantscales of the motion and therefore require considerablecomputational resources. The simulations are carried out on aparallel computer with 12 64-bit CPUs and a total of48GBytes of memory housed at USD and on the facilities ofthe San Diego Supercomputer Center. This project is aninternational collaboration with Dr. K. Schneider (Marseille,France), Dr. W. J. T. Bos (Lyon, France), and Dr. M. Farge(Paris, France).

Virus Removal from Blood (F. G. Jacobitz)Research is currently underway to develop a mathematicalmodel for the flow in hemo-dialysis cartridges. Thesecartridges are used to remove viruses and toxins from blood,such as HIV or hepatitis, and viruses which might be used inbioterrorism, such as smallpox. The mathematical model isdeveloped in close collaboration with experiments performedat Aethlon Medical, Inc.. The model, once validated, will beused to optimize the filter design in order to minimizetreatment time for patients.

Heat Transfer Enhancement (M. McGarry)Natural convection plays an important role in many industrialprocesses where heat must be removed from objects thatgenerate heat. In addition, liquid metals and alloys are used innumerous industrial processes due to their ability to removelarge amounts of heat compared with other liquids. Thecoupling of natural convection with liquid metals occurs in awide variety of industries such as; the nuclear industry forliquid metal fast breeder reactors (LMFBR), heat treatmentand bright annealing furnaces, and the production of high-quality plate glass with the use of a molten metal bath. Ourproject seeks to create a model of a heated solid object thatwill be cooled with various liquid metals. The outcome of theproject will be design equations that can be used for a widerange of operating conditions and liquid metals to determinethe optimal design that will maximize heat transfer from theheated object.

Blood Flow (M. McGarry)Physiological implications for the clotting of an artery,hemostasis, can be found by examining the time-averagedlocal strain rates in the vicinity of the puncture. The time-averaged leakage of fluid leaving a puncture in a pressurizedvessel immersed in a quiescent, miscible medium is studiedunder pulsatile flow conditions. The time-averaged local strainrates at the puncture site can then be investigated. The time-averaged leakage and local strain rates at the puncture arecharacterized as functions of various hydrodynamic andgeometric conditions. Dimensional analysis shows that thetime-averaged leakage rate, Q*, is a function of the meanReynolds number, the Womersely number, the pressure ratiobetween the center of the tube and the external hydrostatic


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pressure, P*, and the hole-to-main tube diameter ratio, D*. A3-D finite volume computational model is constructed forlaminar flow of a Newtonian fluid under pulsatile conditionsand validated with supporting experiments. The time-averagedfractional leakage rate Q* increases with P* and approaches aconstant value at high P*. In addition, the largest Womersleynumber shows the smallest time-averaged leakage rate. Thelargest strain rates are associated with the highest Womersleynumber. The effect of the diameter ratio is examined and thelargest diameter ratio contains the lowest time-averagedleakage rates. While the smallest diameter ratio has the largesttime-averaged strain rates. These strain rates lead to dramaticvariations in platelet deposition for a the different smallarteries.

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