Engineering Commons^™

A Systemic Model Of Development: Strategically Enhancing Students' Cognitive, Psychomotor, Affective And Social Development, Linda Vanasupa, Jonathan Stolk, Trevor S. Harding, Richard N. Savage

Materials Engineering

The challenges of the 21st century create an imperative for engineering educators: to design learning experiences that result in engineering professionals with a sophisticated level of cognitive, psychomotor, social and affective development. We propose a tool for the design process. Our systemic model of development (SMD) is based on a large body of learning theory and empirical data. It maps the relationships among the major factors that influence learning in the form of a causal loop diagram. To demonstrate the value of the SMD, we compared the motivational profiles of a test group (36 students) who took an engineering course …

Application Of Transformative Learning Theory In Engineering Education, John Chen

Mechanical Engineering

The goal of this work-in-progress is to improve student engagement and learning in courses that form the core of a discipline. Such gateway courses represent critical milestones in a student's academic career and have a strong influence on his or her attitude and future success in engineering. We contend that students who struggle in gateway courses do so because they are having difficulty with conceptual transformation, and this project aims to facilitate this change through the ideas advocated within Transformative Learning Theory. The essential elements of this project include the integration of information technologies, provision of rapid feedback to students …

High Resolution Simulation Of Full Aircraft Control At Flight Reynolds Numbers, Scott A. Morton, James R. Forsythe, David R. Mcdaniel, Keith Bergeron, Russell M. Cummings, Stefan Goertz, Jurgen Seidel, Kyle D. Squires

Aerospace Engineering

This paper documents interim results of a three year project to develop a computational method for accurately determining static and dynamic stability and control characteristics of fighter and transport aircraft with various store configurations, as well as the aircraft response to pilot input. In this second year of the project computational data is gathered for a rigid F-16C with no control surface movement in forced motion that approximates flight test maneuvers. "Computational maneuvers" designed to efficiently gather three axes of motion data to build a comprehensive reduced order model are also developed. The data is then post- processed to determine …

Photonics Education Program At California Polytechnic State University, Dennis Derickson, Samuel Agbo, Sean Jobe, John Sharpe, Dan Wasche, Xiaomin Jin

Electrical Engineering

California Polytechnic State University (Cal Poly) has an active photonics-related program. The thrusts of the program are coursework, extensive photonic educational laboratories, an SPIE student branch chapter, and a new Project-Based Learning Institute (PBLI) to promote joint projects with industry.This paper will describe our program for a multidisciplinary approach to photonics education at the undergraduate and master’s degree level.

Academic Integrity Among Engineering Undergraduates: Seven Years Of Research By The E3 Team, Cynthia J. Finelli, Trevor S. Harding, Donald D. Carpenter

Materials Engineering

The E³ Team (Exploring Ethical decision-making in Engineering) is a group of engineering educators and educational researchers who have worked collaboratively since 2000 to understand the underlying causes of academic dishonesty in engineering undergraduate populations. The team was especially motivated by decades of others’ work showing that, when surveyed, engineering students were among those most likely to report frequently cheating. This paper summarizes some of the team’s more important findings from three major studies that surveyed a total of 1300 engineering and humanities undergraduates at eleven institutions. The paper also describes the next phase of the team’s research and …

Exciting Students About Materials Science And Engineering: A Project-Based, Service-Learning Museum Design Course, Katherine C. Chen

Materials Engineering

A new course was developed for Materials Engineering students to design, create, and install interactive, educational displays on Materials Science & Engineering for a science museum at a local K-6 charter school. The course grew out of an ASM Foundation grant “to excite young people in materials, science, and engineering careers,” and the challenge was put forth to Cal Poly students. A formal design sequence was applied to give the students the opportunity to learn about the design process, project management, and teamwork. User profiles were created for the stakeholders, and project values were established. The class partnered with the …

A Design Methodology For Empowering Project-Based Learning, Richard N. Savage

Materials Engineering

One of our primary objectives is to equip undergraduate engineering students to be successful global engineers, ready to face the challenges of the 21st century. Students need to develop self-directed learning skills, systems level thinking, the ability to integrate principles of sustainability into design solutions and recognize that they serve a global community. Project-based learning (PBL) has been identified as an effective process for developing these skills; however, to be effective, project-based learning activities require a clearly articulated design methodology. Engineering students must learn to recognize the similarities and differences between the scientific and design methods. Both can be looked …

Simulated Effects Of Marathon Training On Bone Density, Remodeling, And Microdamage Accumulation Of The Femur, Scott J. Hazelwood, Alesha B. Castillo

Biomedical Engineering

Stress fractures are mechanically induced injuries resulting from fatigue damage to bone due to repetitive loading and are common injuries occurring in runners. In this study, we used computer simulations of marathon training programs to examine the effects of endurance running on femoral density, remodeling, and microdamage accumulation. Simulated remodeling activity increased in the femoral neck and proximal cortex and predicted microdamage increased in all regions examined after 16 weeks for each program. Daily running for three years produced more microdamage than the advanced training schedule over the same time period. Areas of high remodeling and damage corresponded to clinically …

Crack Growth Induced By Sonic Ir Inspection, John C. Chen, Jacob Kephart, Kyle Lick, William T. Riddell

Mechanical Engineering

We have developed an experiment to study the propagation of laboratory-synthesized fatigue cracks under various controlled conditions during Sonic IR inspection. The experiment provides for good repeatability in testing. The parameters of interest include the initial crack length, load history (stress intensity and load ratio) during crack generation, geometry of the crack, material and also the various conditions involving the ultrasonic excitation source. In general, we find that under typical sonic IR inspection conditions, the initial crack will propagate under sonic IR testing. The crack growth after each inspection event varies and exhibits a distribution in length of propagation. The …

Multiobjective Optimization For Optimal Design Of Urban Drainage Systems, Misgana K. Muleta, Paul F. Boulos

Civil and Environmental Engineering

Control of sewer overflows, the leading cause of water pollution in the nation’s water bodies, is vital to reducing risks to public health and protecting the environment. The most common solutions for mitigating sewer overflows include adding storage volume, increasing conduit capacity, expanding pumping capacity, and implementation of real time operational controls to more effectively utilize existing system storage. Obviously, comprehensive modeling and analysis of these sewer systems becomes necessary for developing sound cost-effective and reliable solutions for enhancing system integrity and performance to convey sewer flows without causing overflows. However, identification of the optimal remedial solution that effectively circumvents …

Diluent Hydrocarbon Biodegredation In Laboratory Microcosms Using Anoxic Eletctron Acceptors, Meghann Chell, Laleh Rastagarzadeh, Yarrow Nelson

Civil and Environmental Engineering

Abstract of Paper Presented at Conference.

Volumetric Irrigation Water Pricing Considerations, Charles M. Burt

BioResource and Agricultural Engineering

Volumetric water pricing is a popular topic within donor agencies for irrigation project modernization and sustainability. Implementation of an effective pricing program is quite complex and requires consideration of physical modernization, fee structure, enforcement procedures, and the level of water delivery service. Variations of volumetric water pricing and allocation are discussed.

Ultrasonic Method For Aircraft Wake Vortex Detection, Rebecca J. Rodenhiser, William W. Durgin, Hamid Johari

Office of the Provost Scholarship

This paper describes the experimental proof of concept study for an ultrasonic method of wake vortex detection. This new acoustic method uses travel time of acoustic pulses around a closed path to measure the net circulation within the acoustic path. In this application the closed path encloses the vorticity shed from one side of a Piper PA-28 aircraft wing. Magnitude and sign of circulation detected is comparable to the expected circulation generated by the Piper PA-28 test aircraft. This study demonstrates the validity of the acoustic method in detecting aircraft wake vortices. Further investigations and applications using this technique are …

On The Nature Of Over-Dispersion In Motor Vehicle Crash Prediction Models, Sudeshna Mitra, Simon Washington

Civil and Environmental Engineering

Statistical modeling of traffic crashes has been of interest to researchers for decades. Over the most recent decade many crash models have accounted for extra-variation in crash counts—variation over and above that accounted for by the Poisson density. The extra-variation – or dispersion – is theorized to capture unaccounted for variation in crashes across sites. The majority of studies have assumed fixed dispersion parameters in over-dispersed crash models—tantamount to assuming that unaccounted for variation is proportional to the expected crash count. Miaou and Lord [Miaou, S.P., Lord, D., 2003. Modeling traffic crash-flow relationships for intersections: dispersion parameter, functional form, and …

Chemical Composition Of Groundwater Hydrocarbon Mixtures Before And After Aerobic Biodegradation, Eileen Mick, Kevin Crossley, Yarrow Nelson

Civil and Environmental Engineering

No abstract provided.

The Mechanical And Thick Section Bending Behavior Of Friction Stir Processed Aluminum Plate, D. Hilbert, C. Fuller, M. Mahoney, B. London

Materials Engineering

Friction stir processing (FSP) 2519-T87 aluminum plate results in enhanced ductility, 25% strain at fracture. However, the yield strength in the FSP zone drops to 175 MPa from ~400 MPa. Actively cooling the plate during FSP increases the yield strength to 185 MPa and decreases ductility to 20% strain at fracture. Thick bending of a plate of the alloy was demonstrated after the surface was subjected to FSP.

Improving Dc Power Supply Efficiency With Neural Network Controller, Weiming Li, Xiao-Hua Yu

Electrical Engineering

DC-DC converters can be found in almost every power electronics device. To improve the efficiency and controller response of a DC-DC converter to dynamical ~stem changes, neural network has been chosen as an alternative to classic methods. However, no prior work has been done in the neural network approach for control of a PSFB (phase-Shifted Full-Bridge) converter yet. In this research, a multi-layer feedforward neural network controller is proposed. The neural network based controller has the advantage of adaptive learning ability, and can work under the situation when the input voltage and load current fluctuate. Levenberg-Marquardt backpropagation training algorithm is …

The Use Of Hinged External Fixation To Provide Additional Stabilization For Fractures Of The Distal Humerus, Christopher R. Deuel, Philip Wolinsky, Eric Shepherd, Scott Hazelwood

Biomedical Engineering

Objective: To assess improvements in fixation stability when a hinged unilateral external fixator is used to supplement compromised internal fixation for distal humerus fractures.

Methods: Removing a 1-cm section of the distal humerus in cadaveric whole-arm specimens created a comminuted distal humerus fracture model (AO type 13-A3). Fixation was then performed using different constructs representing optimal, compromised, or supplemented internal fixation. Internal fixation consisted of either 2 reconstruction plates with 1, 2, or 3 (optimal) distal attachment screws, or crossing medial and lateral cortical screws. A hinged external fixator was applied in combination with compromised internal fixation. The stability of …

Development Of A Biofidelic 'Legform' Impact Test Device, John Davis, Peter Schuster

Mechanical Engineering

Current EuroNCAP test specifications attempt to predict pedestrian lower limb injury in a lateral impact with a rigid legform test device developed by the UK's TRL (Transportation Research Lab). Research shows that the measurements taken from this device (knee bending angle, knee shear, and upper tibia acceleration) do not necessarily correspond to accurate injury prediction. Recent research suggests that the primary improvement to the current test device would be a flexible legform, or one that has more biofidelity (i.e., simulates actual human lower limb response).

The work presented in this paper first reviews current legforms developed for pedestrian impact testing, …

Construction Superintendent Skill Sets, David E. Gunderson, Philip Barlow, Allan J. Hauck

Construction Management

This is the first of a series of articles reviewing the results of an ongoing qualitative research project designed to document construction superintendent skill sets and develop postsecondary curricula to support superintendent education. Varying views of the role of the superintendent and an historical perspective are presented in a review of literature. The research methodology for the entire project, as well as this first phase, is presented. Data have been coded and analyzed from the interviews with seven superintendents to date and the results of these analyses are provided. Themes that emerged in these interviews include people skills, understanding the …

The Onset For Compressibility Effects For Aerofoils In Ground Effect, G. Doig, T.J. Barber, E. Leonardi, A.J. Neely

Aerospace Engineering

The influence of flow compressibility on a highly-cambered inverted aerofoil in ground effect is presented, based on two-dimensional computational studies. This type of problem has relevance to open-wheel racing cars, where local regions of high-speed subsonic flow form under favourable pressure gradients, even though the maximum freestream Mach number is typically considerably less than Mach 0.3. An important consideration for CFD users in the field is addressed in this paper, the freestream Mach number at which flow compressibility significantly affects aerodynamic performance. More broadly, for aerodynamicists, the consequences of this are also considered. Comparisons between incompressible and compressible CFD siulations …

Investigation Of The Lead-Free Solder Joint Shear Performance, James Webster, Jianbiao Pan, Brian J. Toleno

Industrial and Manufacturing Engineering

Reflow profile has significant impact on solder joint performance because it influences wetting and microstructure of the solder joint. The purpose of this study is to investigate the effects of reflow profile and thermal shock on the shear performance of eutectic SnPb (SnPb) and Sn3.0Ag0.5Cu (SAC305) solder joints. Test boards were assembled with four different sized surface mount chip resistors (1206, 0805, 0603 and 0402). Nine reflow profiles for SAC 305 and nine reflow profiles for SnPb were developed with three levels of peak temperature (12ºC, 22ºC, and 32ºC above solder liquidus temperature, or 230ºC, 240ºC, and 250ºC for SAC …

A Bimodular Polyconvex Anisotropic Strain Energy Function For Articular Cartilage, Stephen M. Klisch

Mechanical Engineering

A strain energy function for finite deformations is developed that has the capability to describe the nonlinear, anisotropic, and asymmetric mechanical response that is typical of articular cartilage. In particular, the bimodular feature is employed by including strain energy terms that are only mechanically active when the corresponding fiber directions are in tension. Furthermore, the strain energy function is a polyconvex function of the deformation gradient tensor so that it meets material stability criteria. A novel feature of the model is the use of bimodular and polyconvex “strong interaction terms” for the strain invariants of orthotropic materials. Several regression analyses …

Agile Mpc System Linking Manufacturing And Market Strategies, Ahmed M. Deif, Waguih H. Elmaraghy

Industrial Technology and Packaging

Increasing complexity and interdependency in manufacturing enterprises require an agile manufacturing paradigm. This paper considers a dynamic control approach for linking manufacturing strategy with market strategy through a reconfigurable manufacturing planning and control (MPC) system to support agility in this context. A comprehensive MPC model capable of adopting different MPC strategies through distributed controllers of inventory, capacity, and WIP is presented. A hierarchical supervisory controller (referred to as decision logic unit, DLU) that intakes the high-level strategic market decisions and constraints together with feedback of the current manufacturing system state (WIP, production, and inventory levels) and optimally manages the distributed …

Assessment Of Blood Vessel Mimics With Optical Coherence Tomography, Garret T. Bonnema, Kristen O'Halloran Cardinal, James B. Mcnally, Stuart K. Williams, Jennifer K. Barton

Biomedical Engineering

Optical coherence tomography (OCT) is an imaging mo-dality that enables assessment of tissue structural characteristics. Studies have indicated that OCT is a useful method to assess both blood vessel morphology and the response of a vessel to a deployed stent. We evaluated the ability of OCT to visualize the cellular lining of a tissue-engineered blood vessel mimic (BVM) and the response of this lining to a bare metal stent. We develop a side-firing endoscope that obtains intraluminal, longitudinal scans within the sterile bioreactor environment, enabling time-serial assessment. Seventeen BVMs are imaged with the endoscopic OCT system. The BVMs are then …

Teaching And Learning Dc‐Dc Converter Design Using Mathcad, Taufik

Electrical Engineering

This paper presents an approach for teaching and learning dc-dc converter design using MathCAD. MathCAD provides advantages that greatly improve teaching and learning process especially when long and complicated design equations are involved such as those found in dc-dc converters. A design example using Excel is presented and then compared with the same example using MathCAD. Experience learned from using MathCAD in power electronic courses at Cal Poly will be discussed in this paper.

A Multidisciplinary Design Project In Energy Conversion Electromagnetics Course, Ali Shaban, Ahmad Nafisi, Fred Depiero, Taufik

Electrical Engineering

This paper presents a work-in-progress on a new multidisciplinary design project for an Energy Conversion Electromagnetics course at Cal Poly State University. The project is intended to strengthen the skills of electrical and mechanical engineering students by performing design tasks in a multidisciplinary environment. Concurrently, this new design project is implemented to fulfill ABET criterion 3d. The content and format of the project will be described in this paper. Assessments planned for the project will also be discussed.

Quantitative Regional Associations Between Remodeling, Modeling, And Osteocyte Apoptosis And Density In Rabbit Tibial Midshafts, Nicole L. Hedgecock, Tamer Hadi, Andrew A. Chen, Shane B. Curtiss, R. Bruce Martin, Scott J. Hazelwood

Biomedical Engineering

Evidence suggests that osteocyte apoptosis is involved in the adaptive response of bone, although the specific role of osteocytes in the signaling mechanism is unknown. Here, we examined and correlated regional variability in indices of remodeling, modeling, osteocyte apoptosis, and osteocyte density in rabbit tibia midshafts. Histomorphometric analysis indicated that remodeling parameters (BMU activation frequency, osteon density, forming osteon density, and resorption cavity density) were lower in the cranial region compared to other quadrants. In addition, pericortical subregions displayed less remodeling relative to intracortical and endocortical ones. Modeling indices also demonstrated regional variability in that periosteal surfaces exhibited a greater …

Sensitivity Of A Distributed Watershed Simulation Model To Spatial Scale, Misgana K. Muleta, John W. Nicklow, Elias G. Bekele

Civil and Environmental Engineering

The results of distributed watershed models could be sensitive to spatial and temporal scales at which inputs and model parameters are aggregated. This paper reports findings of a detailed sensitivity analysis conducted on the U.S. Department of Agriculture’s distributed watershed simulation model, known as the Soil and Water Assessment Tool (SWAT). The Big Creek Watershed, located in southern Illinois, is used for the study. The model is calibrated to improve accuracy of its streamflow and sediment concentration predictions using observed data at two locations in the study watershed. Streamflow and sediment concentrations that are simulated by the calibrated model at …

Investigating Optimal Capacity Scalability Scheduling In A Reconfigurable Manufacturing System, Ahmed M. Deif, Waguih Elmaraghy

Industrial Technology and Packaging

Responsiveness to dynamic market changes in a cost-effective manner is becoming a key success factor for any manufacturing system in today’s global economy. Reconfigurable manufacturing systems (RMSs) have been introduced to react quickly and effectively to such competitive market demands through modular and scalable design of the manufacturing system on the system level, as well as on the machine components’ level. This paper investigates how RMSs can manage their capacity scalability on the system level in a cost-effective manner. An approach for modeling capacity scalability is proposed, which, unlike earlier approaches, does not assume that the capacity scalability is simply …