Engineering Commons^™

Integrating Engineering Design Challenges Into Secondary Stem Education, Ronald L. Carr

Publications

Engineering is being currently taught in the full spectrum of the P-12 system, with an emphasis on design-oriented teaching (Brophy, Klein, Portsmore, & Rogers, 2008). Due to only a small amount of research on the learning of engineering design in elementary and middle school settings, the community of practice lacks the necessary knowledge of the trajectory of students' learning progressions towards design mastery and expertise and the appropriateness of otherwise established design pedagogies. The issue is even more pressing since many states are embedding engineering into their standards without a clear notion of how engineering (often conceptualized as design) works …

Building A Framework For Engineering Design Experiences In Stem: A Synthesis, Cameron D. Denson

Publications

Since the inception of the National Center for Engineering and Technology Education in 2004, educators and researchers have struggled to identify the necessary components of a “good” engineering design challenge for high school students. In reading and analyzing the position papers on engineering design many themes emerged that may begin to form a narrative for engineering design in a high school setting. Before educators can provide a framework for engineering design in STEM courses, four questions need to be answered: (a) To what degree should engineering design challenges be open-ended or well-structured? (b) What are the relationships between engineering design …

Design Principles For High School Engineering Design Challenges: Experiences From High School Science Classrooms, Christian Schunn

Publications

At the University of Pittsburgh, we have been exploring a range of approaches to design challenges for implementation in high school science classrooms (Apedoe, Reynolds, Ellefson, & Schunn, 2008; Ellefson, Brinker, Vernacchio, & Schunn, 2008; Schunn, Silk, & Apedoe, in press). In general, our approach has always involved students working during class time over the course of many weeks. So, our understanding of what works must be contextualized to that situation (i.e., without significant home support, by students enrolled in traditional classrooms, involving content that is connected to traditional science classrooms). However, our approach has been implemented with thousands of …

Infusing Engineering Design Into High School Stem Courses, Morgan Hynes, Merredith Portsmore, Emily Dare, Elissa Milto, Chris Rogers, David Hammer, Adam Carberry

Publications

Society is recognizing the need to improve STEM education and introduce engineering design concepts before college. In the recent National Academy of Engineers report, Engineering in K-12 Education: Understanding the Status and Improving the Prospects, the authors suggest that the STEM disciplines not be treated as ―silos‖ and that engineering might serve as a motivating context to integrate the four STEM disciplines (Katehi, Pearson, & Feder, 2009). Recent research has suggested that integrated technology and engineering design curriculum can serve as a positive model for mathematics and science learning and retention (Ortiz, 2010; Wendell, 2011). The Tufts University Center for …

Engineering Design Challenges In A Science Curriculum, Arthur Eisenkraft

Publications

Create a light and sound show to entertain your friends. Design an improved safety device for a car. Develop a 2-3 minute voice-over for a sports clip explaining the physics involved in the sport. Modify the design of a roller coaster to meet the needs of a specific group of riders. Design an appliance package for a family limited by the power and energy of wind generator. Develop a museum exhibit to acquaint visitors with the atom and nucleus and create a product that can be sold at the museum store after visitors leave your exhibit. All of these challenges …

Engineering Design Challenges In High School Stem Courses A Compilation Of Invited Position Papers, Daniel L. Householder

Publications

Since its initial funding by the National Science Foundation in 2004, the National Center for Engineering and Technology Education (NCETE) has worked to understand the infusion of engineering design experiences into the high school setting. Over the years, an increasing number of educators and professional groups have participated in the expanding initiative seeking to acquaint all students with engineering design. While there is strong support for providing students with engineering design experiences in their high school STEM courses, the lack of consensus on purposes and strategies has become increasingly apparent as the work continues. Among the unsettled issues are the …

Transit System Evaluation Process: From Planning To Realization, K Bartman, Jennifer Ogle, Mashrur Chowdhury, Anne Dunning

Publications

Many frameworks exist to help transit agencies plan, operate, and monitor the performance of transit in rural and urban communities. No framework integrates these three critical business practices into one coherent and flexible framework useful to rural and small-sized cities. The primary objective of this research was to integrate planning, operations, and performance measurement activities into a framework designed to evaluate transit in the context of overall mobility. By combining planning, evaluation, and performance monitoring processes, a succinct framework useful to transit agencies and planners was created. In addition to city entities, colleges and universities operating or contracting transit systems …

Observations On Braided Thin Wire Nucleate Boiling In Microgravity, Justin P. Koeln, Jeffrey C. Boulware, Heng Ban, Jr Dennison

Publications

A microgravity experiment was conducted on the Space Shuttle Endeavor (STS-108) to observe sustained nucleate boiling of water. Subcooled water was boiled with a single strand and a braid of three 0.16. mm diameter and 80. mm long Nichrome resistive wires. A CCD video camera recorded the experiment while six thermistors recorded the temperature of the fluid at various distances from the heating element. This paper reports experimental results in observations, measurements, and data analysis. Bubble explosions were found to take place shortly after the onset of boiling for both the single and braid of wires. The explosion may produce …

Dispersive Wave Equations For Solids With Microstructure, A. Berezovski, Juri Engelbrecht, Mihhail Berezovski

Publications

The dispersive wave motion in solids with microstructure is considered in the one-dimensional setting in order to understand better the mechanism of dispersion. It is shown that the variety of dispersive wave propagation models derived by homogenization, continualisation, and generalization of continuum mechanics can be unified in the framework of dual internal variables theory.

Risk Perception Analysis Of A Small Aircraft Transportation System, David S. Ferrel, Thomas Q. Carney, Scott R. Winter

Publications

This study examines the impact and relationship between demographic factors and risk perceptions toward Small Aircraft Transportation Systems (SATS). The study included 178 participants who responded to an electronic survey administered to Purdue University faculty members and to selected leaders within the Purdue Intercollegiate Athletics department. Participants were surveyed as to their demographic identities including gender, age, academic position, and aviation familiarity, as well as their perceptions of physical, financial, and status risk from a SATS program. Results of this study showed that certain demographic factors are significant predictors of certain SATS travel risk perceptions. Participants’ intentions to travel via …

An Overview Of The Low-Cost Carrier Model In The Russian Market, Tamilla Curtis, Dawna L. Rhoades

Publications

This study provides an overview of the low-cost carrier (LCC) model in the Russian market. The LCC model seeks to achieve a competitive advantage through the reduction of operating costs, below the traditional airline model. Since Russia is an emerging and developing economy, airlines face a high level of uncertainty. Despite the fact that the Russian aviation market is dominated by a few large carriers, Russian lowcost airlines such as SkyExpress and Avianova have been growing rapidly since starting their operations. While Russian LCCs follow the traditional LCC model, some differences are apparent as a result of the specifics of …

Nanoindentation And Plasticity In Nanocrystalline Ni Nanowires: A Case Study In Size Effect Mitigation, F. Sansoz, Virginie Rollin

Publications

We examine the processes of spherical indentation and tension in Ni nanowires and thin films containing random distributions of nanoscale grains by molecular dynamics simulations. It is shown that the resistance to nanoindentation of nanocrystalline Ni nanowires with diameters of 12 and 30 nm tends not to depend on the wire diameter and free surfaces, contrary to nanoindentation in single-crystalline nanowires. Accommodation of plastic deformation by grain boundary sliding suggests a mitigation strategy for sample boundary effects in nanoscale plasticity.

Development Of A Physical Windkessel Module To Re-Create In Vivo Vascular Flow Impedance For In Vitro Experiments, Ethan Kung, Charles A. Taylor

Publications

To create and characterize a physical Windkessel module that can provide realistic and predictable vascular impedances for in vitro flow experiments used for computational fluid dynamics validation, and other investigations of the cardiovascular system and medical devices. We developed practical design and manufacturing methods for constructing flow resistance and capacitance units. Using these units we assembled a Windkessel impedance module and defined its corresponding analytical model incorporating an inductance to account for fluid momentum. We tested various resistance units and Windkessel modules using a flow system, and compared experimental measurements to analytical predictions of pressure, flow, and impedance. The resistance …

Developing Proactive Methods For General Aviation Data Collection, Scott Shappell, Carla Hackworth, Kali Holcomb, John Lanicci, Massoud Bazargan, Jaclyn Baron, Rebecca Iden, Daniel Halperin

Publications

Introduction. Over the last 20 years, nearly 40,000 general aviation (GA) aircraft were involved in accidents, roughly 20% of which were fatal. To address this safety concern, scientists have often relied on accident data. Because of the rare nature of accidents, commercial aviation incident and near miss data may prove to be useful sources of safety information. In one such study, the National Transportation Safety Board interviewed GA pilots that were flying near a weather-related accident in pursuit of a different perspective than that of the accident pilot. Interviewing GA pilots about their own weather-related event may provide similar …

Challenges To Informed Peer Review Matching Algorithms, Matthew Verleger, Heidi Diefes-Dux, Matthew W. Ohland, Mary Besterfield-Sacre, Sean Brophy

Publications

Background Peer review is a beneficial pedagogical tool. Despite the abundance of data instructors often have about their students, most peer review matching is by simple random assignment. In fall 2008, a study was conducted to investigate the impact of an informed algorithmic assignment method, called Un‐weighted Overall Need (UON), in a course involving Model‐Eliciting Activities (MEAs). The algorithm showed no statistically significant impact on the MEA Final Response scores. A study was then conducted to examine the assumptions underlying the algorithm.

Purpose (Hypothesis) This research addressed the question: To what extent do the assumptions used in making informed peer …

Defining An Abrasion Index For Lunar Surface Systems As A Function Of Dust Interaction Modes And Variable Concentration Zones, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street Jr.

Publications

Unexpected issues were encountered during the Apollo era of lunar exploration due to detrimental abrasion of materials upon exposure to the fine-grained, irregular shaped dust on the surface of the Moon. For critical design features involving contact with the lunar surface and for astronaut safety concerns, operational concepts and dust tolerance must be considered in the early phases of mission planning. To systematically define material selection criteria, dust interaction can be characterized by two-body or three-body abrasion testing, and sub-categorically by physical interactions of compression, rolling, sliding and bending representing specific applications within the system. Two-body abrasion occurs when a …

Numerical Simulation Of Marina Storage Fires Using Measured Composite Fire And Thermal Properties, Lulu Sun, Aixi Zhou, Andrew Valente

Publications

Fire test data of boats in rack storage are needed to establish more specific requirements for fire control and protection for this type of vessel in high piled rack storage configurations. Since there is no current large or full scale fire test data available, we have embarked upon testing fire and thermal properties of boat material, fiber reinforced polymer (FRP) composite, by using Differential Scanning Calorimetry, and Cone Calorimeter in order to determine the most effective method to provide sprinkler protection to an indoor boat storage facility. Fire and thermal properties of FRP were obtained from experiments and incorporated into …

Deformation Waves In Microstructured Materials: Theory And Numerics, Juri Engelbrecht, Arkadi Berezovski, Mihhail Berezovski

Publications

A linear model of the microstructured continuum based on Mindlin theory is adopted which can be represented in the framework of the internal variable theory. Fully coupled systems of equations for macro-motion and microstructure evolution are represented in the form of conservation laws. A modification of wave propagation algorithm is used for numerical calculations. Results of direct numerical simulations of wave propagation in periodic medium are compared with similar results for the continuous media with the modelled microstructure. It is shown that the proper choice of material constants should be made to match the results obtained by both approaches

Dynamic Solidification In Nanoconfined Water Films, Peter M. Hoffmann, Shah H. Khan, George Matei, Shivprasad Patil

Publications

Mechanical properties of nanoconfined water layers are still poorly understood and continue to create controversy, despite their importance for biology and nanotechnology. We report on dynamic nanomechanical measurements of water films compressed to a few single molecular layers. We show that the mechanical properties of nanoconfined water layers change significantly with their dynamic state. In particular, we observed a sharp transition from viscous to elastic response even at extremely slow compression rates, indicating that mechanical relaxation times increase dramatically once water is compressed to less than 3–4 molecular layers.

Analytic Treatment Of Vortex States In Cylindrical Superconductors In Applied Axial Magnetic Field, Andrei Ludu, J. Van Deun, M. V, Milosevic, A. Cuyt, F. M. Peeters

Publications

We solve the linear Ginzburg–Landau GL equation in the presence of a uniform magnetic field with cylindrical symmetry and we find analytic expressions for the eigenfunctions in terms of the confluent hypergeometric functions. The discrete spectrum results from an implicit equation associated to the boundary conditions and it is resolved in analytic form using the continued fractions formalism. We study the dependence of the spectrum and the eigenfunctions on the sample size and the surface conditions for solid and hollow cylindrical superconductors. Finally, the solutions of the nonlinear GL formalism are constructed as expansions in the linear GL eigenfunction basis …

Three-Body Abrasion Testing Using Lunar Dust Simulants To Evaluate Surface System Materials, Ryan L. Kobrick, Kenneth G. Budinski, Kenneth W. Street Jr., David M. Klaus

Publications

Numerous unexpected operational issues relating to the abrasive nature of lunar dust, such as scratched visors and spacesuit pressure seal leaks, were encountered during the Apollo missions. To avoid reoccurrence of these unexpected detrimental equipment problems on future missions to the Moon, a series of two- and three-body abrasion tests were developed and conducted in order to begin rigorously characterizing the effect of lunar dust abrasiveness on candidate surface system materials. Two-body scratch tests were initially performed to examine fundamental interactions of a single particle on a flat surface. These simple and robust tests were used to establish standardized measurement …

Elements Of Study On Dynamic Materials, Marine Rousseau, Gerard A. Maugin, Mihhail Berezovski

Publications

As a preliminary study to more complex situations of interest in small-scale technology, this paper envisages the elementary propagation properties of elastic waves in one-spatial dimension when some of the properties (mass density, elasticity) may vary suddenly in space or in time, the second case being of course more original. Combination of the two may be of even greater interest. Toward this goal, a critical examination of what happens to solutions at the crossing of pure space-like and time-like material discontinuities is given together with simple solutions for smooth transitions and numerical simulations in the discontinuous case. The effects on …

Scan Loss Pattern Synthesis For Adaptive Array Ground Stations, William C. Barott, Mary Ann Ingram, Paul G. Steffes

Publications

We present several techniques for maximizing the contact time between low Earth orbiting satellites (LEOs) and a ground station (GS). The GS comprises an adaptive array of electronically steered space-fed lenses (SFLs). Each SFL is manufactured as a low-cost printed circuit with the result that it exhibits scanning loss. By differently orienting the boresights of the SFLs in the adaptive array, the SFL's scanning losses can be made to optimally complement the path loss of the LEO, thereby reducing the cost of the GS while maximizing the download capacity of the satellite link. The optimization, implemented with a genetic algorithm …

A Design-Build-Test-Fly Project Involving Modeling, Manufacturing, And Testing, Scott Post, Shankar Seetharaman, Sree Abimannan

Publications

This paper describes a junior-level semester-long class project for students in Fluid Mechanics courses. The goals of the project are to introduce students to engineering design, project management, and to incorporate material from other courses in engineering graphics, numerical methods, instrumentation and measurements, and manufacturing processes in a single project. The project focuses on airfoil design using computational tools, and the main emphasis lies on verification of results obtained from computational methods with experimentally measured values. Students will use the airfoil shape they select to make wings to go on a model foam glider. The final part of the project …

Effect Of Simulated Visual Impairment On Nighttime Driving Performance, Joanne Wood, Alex Chaparro, Trent Carberry, Byoung Sun Chu

Publications

Purpose. This study investigated the effects of simulated visual impairment on nighttime driving performance and pedestrian recognition under real-road conditions.

Methods. Closed road nighttime driving performance was measured for 20 young visually normal participants (M = 27.5 +- 6.1 years) under three visual conditions: normal vision, simulated cataracts, and refractive blur that were incorporated in modified goggles. The visual acuity levels for the cataract and blur conditions were matched for each participant. Driving measures included sign recognition, avoidance of low contrast road hazards, time to complete the course, and lane keeping. Pedestrian recognition was measured for pedestrians wearing either black …

Standardization Of A Volumetric Displacement Measurement For Two-Body Abrasion Scratch Test Data Analysis, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street Jr.

Publications

A limitation has been identified in the existing test standards used for making controlled, two-body abrasion scratch measurements based solely on the width of the resultant score on the surface of the material. A new, more robust method is proposed for analyzing a surface scratch that takes into account the full three-dimensional profile of the displaced material. To accomplish this, a set of four volume displacement metrics are systematically defined by normalizing the overall surface profile to statistically denote the area of relevance, termed the “Zone of Interaction” (ZOI). From this baseline, depth of the trough and height of the …

Effect Of Machining Feed On Surface Roughness In Cutting 6061 Aluminum, Mathew Kuttolamadom, Sina Hamzehlouia, Laine Mears

Publications

The general manufacturing objective during the fabrication of automotive components, particularly through machining, can be stated as the striving to achieve predefined product quality characteristics within equipment, cost and time constraints. The current state of the economy and the consequent market pressure has forced vehicle manufacturers to simultaneously reduce operating expenses along with further improving product quality. This paper examines the achievability of surface roughness specifications within efforts to reduce automotive component manufacture cycle time, particularly by changing cutting feeds. First, the background and attractiveness of aluminum as a lightweight automotive material is discussed. Following this, the methodologies employed for …

Stability Of Fully Nonlinear Stokes Waves On Deep Water: Part 1. Perturbation Theory, Shahrdad Sajjadi, David L. Ross

Publications

We consider a full set of harmonics for the Stokes wave in deep water in the absence of viscosity, and examine the role that higher harmonics play in modifying the classical Benjamin-Feir instability. Using a representation of the wave coefficients due to Wilton, a perturbation analysis shows that the Stokes wave may become unbounded due to interactions between the N^th harmonic of the primary wave train and a set of harmonics of a disturbance. If the frequency of the n^th harmonic is denoted Ꙍ_n = Ꙍ(1 ± ꭉ) then instability will occur if

√2 k n^{n …}

Design Assessment: Consumer Reports Style, Todd R. Kelley

Publications

The article analyzes a design assessment-based activity, in which students are asked to evaluate an existing technology through a Consumer Reports-style approach. According to H. Petroski, the exposure of students to several design examples is important to start learning the basic elements needed in the design process. It claims that the activity will enable students to sharpen their knowledge in several areas including identifying design constraints and criteria, training via study of open designs, and practicing engineering design methods for optimization. It suggests that these are important skills for creating the student's capacity to undertake bigger design activities.

Engineering Professional Development Design For Secondary School Teachers: A Multiple Case Study, Jenny L. Daugherty

Publications

The effectiveness of teachers has been regarded as crucial to the success of standards-based reform (Fishman, Marx, Best, & Tal, 2003). Research, particularly within science and mathematics, has underscored the need for professional development to help teachers understand (a) subject matter, (b) learners and learning, and (c) teaching methods (Loucks-Horsley, 1999). In addition to focusing on teacher professional development, national reform efforts have also emphasized science, technology, engineering, and mathematics (STEM) education (i.e., Rising Above the Gathering Storm, NRC, 2006). While substantial work has been conducted in mathematics and science, the efforts in technology and engineering education are much less …