Engineering Commons^™

Co2 Sequestration In Cement-Based Materials During Mixing Process Using Carbonated Water And Gaseous Co2, Jacek Kwasny, P. A. Muhammed Basheer, Mark I. Russell, William Doherty, Kieran Owens, Neil Ward

International Conference on Durability of Concrete Structures

This paper presents selected findings from a recently completed research project, aimed at the investigation of CO₂ sequestration in cement-based materials during the early stages of hydration when the cement paste is being mixed. Portland cement pastes were carbonated during the mixing process, using both carbonated water and gaseous CO₂, and their properties were compared to the control non-carbonated mix. All mixes were prepared in a purpose-designed chamber that permitted carbonated water and gaseous CO₂ to be mixed with the cementbased materials during the mixing process, without losses of CO₂ to the external environment. Temperature …

Experimental Study On Carbonation Of Steel Fiber Reinforced Concrete, Yan Wang, Ditao Niu, Zhenping Dong

International Conference on Durability of Concrete Structures

With the steel fiber reinforced concrete (SFRC) used more and more widely in some large-span structures, large tunnel linings, dam structures, military engineering, and some other major projects, its durability arouses more and more concerns. In this paper carbonation test of SFRC was conducted. The rule for the mixing amount of steel fiber (0, 0.5, 1.0, 1.5, and 2.0%) to affect the carbonation depth of concrete and the strength developing rule of SFRC after carbonation test were researched. To analyze the property change rules from micro perspective of SFRC after carbonation, the pore structure of SFRC after carbonation was tested. …

Striping Truck Utilization Project, Jon R. Padfield, James Handy

JTRP Posters

This poster highlights research completed by the Joint Transportation Research Program (JTRP) led by Jon Padfield and James Handy, Purdue University for JTRP project SPR-3722, “Striping Truck Utilization for Crawfordsville and Greenfield District.” This poster highlights the transformation of striping trucks at both districts using Value Stream Mapping (VSM) through the Technical Assistance Program.

Graphical Performance Measures For Practitioners To Triage Split Failure Trouble Calls, Richard S. Freije, Alexander M. Hainen, Amanda L. Stevens, Howell Li, W Benjamin Smith, Hayley Summers, Christopher M. Day, James R. Sturdevant, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

No abstract provided.

Improving Intersection Behavior Through Delay-Based Left Turn Phase Initiation, Steven M. Lavrenz, Alexander M. Hainen, Amanda L. Stevens, Christopher M. Day, Howell Li, Richard Freije, W Benjamin Smith, Hayley Summers, James R. Sturdevant, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

No abstract provided.

Assessing Longitudinal Arterial Performance And Traffic Signal Retiming Outcomes, Steven M. Lavrenz, Christopher M. Day, W Benjamin Smith, James R. Sturdevant, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

No abstract provided.

High-Resolution Event-Based Data At Diamond Interchanges: Performance Measures And Optimizing Ring Displacement, Alexander M. Hainen, Amanda L. Stevens, Richard S. Freije, Christopher M. Day, James R. Sturdevant, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

No abstract provided.

Performance Ranking Of Arterial Corridors Using Travel Time And Travel Time Reliability Metrics, Christopher M. Day, Stephen Remias, Howell Li, Michelle M. Mekker, Margaret L. Mcnamara, Ed Cox, Darcy M. Bullock

Lyles School of Civil Engineering Faculty Publications

No abstract provided.

The Importance Of Formative Assessment In Science And Engineering Ethics Education: Some Evidence And Practical Advice, Matthew W. Keefer, Sara E. Wilson, Harry Dankowicz, Michael C. Loui

School of Engineering Education Faculty Publications

Recent research in ethics education shows a potentially problematic variation in content, curricular materials, and instruction. While ethics instruction is now widespread, studies have identified significant variation in both the goals and methods of ethics education, leaving researchers to conclude that many approaches may be inappropriately paired with goals that are unachievable. This paper speaks to these concerns by demonstrating the importance of aligning classroom-based assessments to clear ethical learning objectives in order to help students and instructors track their progress toward meeting those objectives. Two studies at two different universities demonstrate the usefulness of classroom-based, formative assessments for improving …

Development Of An Instrument To Assess Attitudes Toward Science, Technology, Engineering, And Mathematics (Stem), Tamara J. Moore, Selcen Guzey, Michael Harwell

School of Engineering Education Faculty Publications

There is a need for more students to be interested in science, technology, engineering, and mathematics (STEM) careers to advance U.S. competitiveness and economic growth. A consensus exits that improving STEM education is necessary for motivating more students to pursue STEM careers. In this study, a survey to measure student (grades 4-6) attitudes toward STEM and STEM careers was developed and administered to 662 students from two STEM-focused and three comprehensive (non-STEM focused) schools. Cronbach’s alphas for the whole survey and subscales indicated a high internal consistency. Statistically significant difference in means between students attending the STEM-focused and comprehensive schools …

Optical Properties Of Gallium-Doped Zinc Oxide-A Low-Loss Plasmonic Material: First-Principles Theory And Experiment, Jongbum Kim, Gururaj V. Naik, Alexander V. Gavrilenko, Krishnaveni Dondapati, Vladimir I. Gavrilenko, S. M. Prokes, O. J. Glembocki, V. M. Shalaev, Alexandra Boltasseva

Birck and NCN Publications

Searching for better materials for plasmonic and metamaterial applications is an inverse design problem where theoretical studies are necessary. Using basic models of impurity doping in semiconductors, transparent conducting oxides (TCOs) are identified as low-loss plasmonic materials in the near-infrared wavelength range. A more sophisticated theoretical study would help not only to improve the properties of TCOs but also to design further lower-loss materials. In this study, optical functions of one such TCO, gallium-doped zinc oxide (GZO), are studied both experimentally and by first-principles density-functional calculations. Pulsed-laser-deposited GZO films are studied by the x-ray diffraction and generalized spectroscopic ellipsometry. Theoretical …

Spatial Spectrograms Of Vibrating Atomic Force Microscopy Cantilevers Coupled To Sample Surfaces, Ryan Wagner, Arvind Raman, Roger Proksch

Birck and NCN Publications

Many advanced dynamic Atomic Force Microscopy (AFM) techniques such as contact resonance, force modulation, piezoresponse force microscopy, electrochemical strain microscopy, and AFM infrared spectroscopy exploit the dynamic response of a cantilever in contact with a sample to extract local material properties. Achieving quantitative results in these techniques usually requires the assumption of a certain shape of cantilever vibration. We present a technique that allows in-situ measurements of the vibrational shape of AFM cantilevers coupled to surfaces. This technique opens up unique approaches to nanoscale material property mapping, which are not possible with single point measurements alone. (C) 2013 AIP Publishing …

Integrating Information Into The Engineering Design Process, Michael Fosmire, David Radcliffe

Purdue University Press Books

Engineering design is a fundamental problem-solving model used by the discipline. Effective problem-solving requires the ability to find and incorporate quality information sources. To teach courses in this area effectively, educators need to understand the information needs of engineers and engineering students and their information gathering habits. This book provides essential guidance for engineering faculty and librarians wishing to better integrate information competencies into their curricular offerings. The treatment of the subject matter is pragmatic, accessible, and engaging. Rather than focusing on specific resources or interfaces, the book adopts a process-driven approach that outlasts changing information technologies.

After several chapters …

The Role Of Oxygen In The Uptake Of Deuterium In Lithiated Graphite, C. N. Taylor, J. Dadras, Kara E. Luitjohan, Jean P. Allain, P. S. Kristic, C. H. Skinner

Birck and NCN Publications

We investigate the mechanism of deuterium retention by lithiated graphite and its relationship to the oxygen concentration through surface sensitive experiments and atomistic simulations. Deposition of lithium on graphite yielded 5%-8% oxygen surface concentration and when subsequently irradiated with D ions at energies between 500 and 1000 eV/amu and fluences over 10(16) cm(-2) the oxygen concentration rose to between 25% and 40%. These enhanced oxygen levels were reached in a few seconds compared to about 300 h when the lithiated graphite was allowed to adsorb oxygen from the ambient environment under equilibrium conditions. Irradiating graphite without lithium deposition, however, resulted …

Limit For Thermal Transport Reduction In Si Nanowires With Nanoengineered Corrugations, Sean E. Sullivan, Keng-Hua Lin, Stanislav Avdoshenko, Alejandro Strachan

Birck and NCN Publications

Non-equilibrium molecular dynamics simulations reveal that the thermal conductance of Si nanowires with periodic corrugations is lower than that of smooth wires with cross-sections equivalent to the constricted portions. This reduction in conductance is up to 30% and tends to plateau with increasing corrugation height. Spatially resolved temperature and heat current maps provide a microscopic understanding of this effect; we find that 80% of the heat current is carried through the constricted area even for high-amplitude corrugations. More importantly, we show that temperature gradient inversion and heat current vortices at the ridge peaks establish fundamental limits on maximum conductance reduction. …

Homogeneous Algan/Gan Superlattices Grown On Free-Standing (1(1)Over-Bar00) Gan Substrates By Plasma-Assisted Molecular Beam Epitaxy, Jiayi Shao, Dmitri N. Zakharov, Collin Edmunds, Oana Malis, Michael J. Manfra

Birck and NCN Publications

Two-dimensional and homogeneous growth of m-plane AlGaN by plasma-assisted molecular beam epitaxy has been realized on free-standing (1 (1) over bar 00) GaN substrates by implementing high metal-to-nitrogen (III/N) flux ratio. AlN island nucleation, often reported for m-plane AlGaN under nitrogen-rich growth conditions, is suppressed at high III/N flux ratio, highlighting the important role of growth kinetics for adatom incorporation. The homogeneity and microstructure of m-plane AlGaN/GaN superlattices are assessed via a combination of scanning transmission electron microscopy and high resolution transmission electron microscopy (TEM). The predominant defects identified in dark field TEM characterization are short basal plane stacking faults …

Laboratory Testing Of Railroad Flatcars For Use As Highway Bridges On Low-Volume Roads To Determine Ultimate Strength And Redundancy, Teresa L. Washeleski, Robert Connor, Jason B. Lloyd

Indiana Local Technical Assistance Program (LTAP) Technical Reports

Railroad flatcars (RRFCs) are a convenient option to replace existing deteriorating bridge structures on low-volume roads. They are typically used as the bridge superstructure by placing two or more flatcars side-by-side to achieve the desired bridge width. Utilizing RRFCs as a bridge allows for rapid construction and greater cost savings compared to traditional practices. These benefits make them an attractive solution for rural communities in Indiana, as well as other states.

Uncertainty remains about the response under higher loads than could be easily achieved in the field and the level of redundancy of railroad flatcar bridges. Using RRFCs as bridges …

Role Of Atomic Variability In Dielectric Charging: A First-Principles-Based Multiscale Modeling Study, Ravi Pramod Kumar Vedula, Sambit Palit, Muhammad A. Alam, Alejandro Strachan

Birck and NCN Publications

We present a dielectric charging model that combinesab initiocalculations of trap levels with a continuum-level transport model and apply it to interpret charging currents in amorphous silicon nitride. Density functional theory calculations on an ensemble of structures predict a distribution of electron trap levels up to 1.8 eV below the conduction band edge and provide insight into the physical trapping mechanisms. Incorporating this information in the continuum model, as opposed to the standard approach of a single adjustable trap level, not only leads to a more accurate description of experimental current transients in metal-insulator-metal capacitors, but also to a more …

Rheological Investigation Of The Shear Strength, Durability, And Recovery Of Alginate Rafts Formed By Antacid Medication In Varying Ph Environments, Brooke M. Elliott, Kathleen E. Steckbeck, Lisa R. Murray, Kendra Erk

School of Materials Engineering Faculty Publications

The mechanical response of alginate rafts formed by mixing liquid alginate antacid medication (Gaviscon® Extra Strength Liquid Antacid) with acidic solutions was investigated by deforming isolated rafts in a shear rheometer. As rafts were deformed to varying magnitudes of applied strain, rheological parameters were identified and related to the overall strength, durability, and recoverability of rafts formed at different pH (1.1 – 1.7) and aging conditions (0.5 – 4 hr). Rafts formed in the lowest acidity solutions (pH 1.4, 1.7) were elastically weak (G₀’ = 60, 42 Pa for un-aged raft) yet maintained their elasticity during applied …

The Humanistic Side Of Engineering: Considering Social Science And Humanities Dimensions Of Engineering In Education And Research, Morgan Hynes, Jessica Swenson

Journal of Pre-College Engineering Education Research (J-PEER)

Mathematics and science knowledge/skills are most commonly associated with engineering’s pre-requisite knowledge. Our goals in this paper are to argue for a more systematic inclusion of social science and humanities knowledge in the introduction of engineering to K-12 students. As part of this argument, we present a construct for framing the humanistic side of engineering with illustrative examples of what appealing to the humanistic side of engineering can look like in a classroom setting, and opportunities for research that examines the dynamics the humanistic side of engineering introduces into engineering learning and teaching. The illustrative examples are drawn from interactions …

Secondary Students' Conceptual Understanding Of Engineering As A Field, Devlin B. Montfort, Shane Brown, Victoria Whritenour

Journal of Pre-College Engineering Education Research (J-PEER)

Researchers have long been interested in how to recruit and retain more and more diverse students into engineering programs. One consistent challenge in this research is understanding the impacts of interventions from the point of view of the student, and how their preconceptions may influence that effectiveness. This study investigated how secondary students understand the concept of engineering, including what engineering is and what engineers do. The purpose of this work was to describe students’ conceptions of engineering, and to determine how those perceptions relate to student interest in engineering careers. The investigation was founded on the theoretical framework of …

Global Change Factors On Ecosystem Invasibility, Raj Lal, Jeffrey Dukes, Michael J. Schuster, Nick G. Smith

The Summer Undergraduate Research Fellowship (SURF) Symposium

Current climate and human-induced changes are projected to alter many regimes of ecosystem functioning. It is projected that invasive species, nonnative species that can be of great detriment to an ecosystem, will benefit under these conditions. The Prairie Invasion and Climate Experiment (PRICLE) studies the effects of two global change factors – N addition and altered precipitation – on invasive species success and the traits that are selected for in a mixed-grass prairie ecosystem. PRICLE is a two by two factorial design over three replications in a restored mixed-grass prairie ecosystem. The major findings from the community traits examination of …

Validating The Critical Engineering Literacy Test (Celt) With Cognitive Interviews, Margot L. Keimig, Senay Purzer

The Summer Undergraduate Research Fellowship (SURF) Symposium

The CELT learning assessment focuses on the critical thinking skills of engineering students and allows for the improvement of information literacy, one’s ability identifying and implementing important information. With the pairing of cognitive interviewing, the CELT will allow for the identification of errors and will better determine the reasoning in the decisions made by the students taking the test. The CELT test uses multiple choice and open response questions to evaluate the students and the areas where improvements need to be made. Over the course of the year, the students’ information literacy skills will be expanded and then re-evaluated at …

Visualizing Mechanics: Improving Student Learning Through Video Demonstrations, Blake A. Wetherton, Olumide A. Awofeso, Carolyn E. Creighton, Adam F. Potrzebowski, Charles M. Krousgrill, Jeffrey F. Rhoads

The Summer Undergraduate Research Fellowship (SURF) Symposium

The Purdue Mechanics Freeform Classroom (PMFC) is a project that seeks to reform engineering mechanics education by integrating content and technology; enhancing communication between students, their peers, and instructors; accommodating a broader range of learning styles; and facilitating greater depths of understanding. In an attempt to increase the PMFC’s efficacy, a series of demonstration videos has been produced. As demonstrated by the popularity and pervasiveness of websites such as YouTube, short videos have the potential to captivate audiences. As such, these videos have incredible promise in educational contexts. In the PMFC series of videos, entitled Visualizing Mechanics, each imitates the …

Improving Data Quality For A Dairy Pollutant Emissions Study, Ian K. Hahus, Albert J. Heber

The Summer Undergraduate Research Fellowship (SURF) Symposium

The National Air Emissions Monitoring Study (NAEMS) was sanctioned by the EPA to determine the characteristics of airborne pollutant emissions from confined broiler, egg, pork, and dairy housing. Fifteen representative monitoring sites were selected around the U.S., at which influent and effluent pollutant concentrations were measured in conjunction with airflow and climatic data. Due to the monumental nature of this study and the potential ramifications of its findings, it is of vital importance that the data collected by the researchers and utilized by the EPA be as complete and accurate as possible. To improve the validity of the data collected …

Active Dense Tensegrity Structure: A Novel Concept For Shape Morphing Structures, Zhiwei Wu, Thomas Siegmund

The Summer Undergraduate Research Fellowship (SURF) Symposium

Shape morphing is of relevance for advanced engineering systems such as future aerospace vehicles. Tensegrity structures, a structure comprised of a set of discontinuous compressed struts held together with a continuous web of tensioned cables, can function as the foundation of a shape morphing system (Keith et al, 2007). However, the classic tensegrity structures may not be ideal in all configurations because the space within the structure is not utilized. As an alternative, the present work proposes a dense tensegrity system as an assembly of cables carrying tensions only and polyhedral elements under compression only. An active dense tensegrity can …

Cis Map Drawer Visualization System, Hanye Xu, David Ebert

The Summer Undergraduate Research Fellowship (SURF) Symposium

U.S. Citizenship and Immigration Services (USCIS) is the government agency that manages immigration to the United States. They are not only working on filing documents, but also analyzing those data they have. They require help from a visualization system to know the trend of immigration among offices across the country over time. We developed a project called CIS Map Drawer that is used to help build a visualization system for USCIS in order to analyze immigration data easily. This system makes use of a map view, a calendar visual representation, line charts, pixel drawing and other analysis tools to improve …

Detection Of Foodborne Pathogens By Micro-Filtration Using A Continuous Cell Concentrator Device, Klaire E. Jeffries, Eduardo Ximenes, Michael R. Ladisch

The Summer Undergraduate Research Fellowship (SURF) Symposium

Protecting consumers from foodborne illness is an important health concern facing the food industry today. An important deficiency exposed by foodborne illness is the inability to track contaminated food back to the source in a timely manner. Although there are established methods that detect bacterial pathogen contamination, they are limited in distinguishing viable bacteria reliably and quickly. Currently, food pathogen testing requires lengthy culture steps, which many times are delayed even longer due to the lack of in-house testing labs. Typically, two to three days elapses between when the food is sampled and the test results are available. This study …

D-Tunes: Configuration Engine For Geo-Replicated Cloud Storage, Jiawei Wang, Sanjay Rao

The Summer Undergraduate Research Fellowship (SURF) Symposium

When developing a web-based application, developers are facing stringent requirements to balance the latency, scalability and availability for their cloud database. Application developers need a specific replication configuration strategy based on the requirement of their application. To deal with this problem, some geo-replicated cloud strategy systems have emerged recently, like Cassandra. This project serves to design a web tool that can help configure the best replication strategies for geo-distributed data stores, which uses quorum-based protocols. Currently, our web tool D-Tunes, require a minimum input from users and generate specific scripts based on the inputs user provided. The program running these …

Radiation Intensity Of A Turbulent Sooting Ethylene Flame, Ryan M. Hartman, Jay P. Gore

The Summer Undergraduate Research Fellowship (SURF) Symposium

Turbulent sooting flame radiation is relevant to applications ranging from fire safety to gas turbine engines. The complex direct interactions of soot and radiation intensity are of particular importance when creating accurate soot prediction models. Previous studies have measured gas-band and broadband radiation intensity from turbulent sooting flames. The focus of the current study is the characterization of radiation intensity emanating from soot. A high-speed infrared camera (FLIR Phoenix) was used to acquire time-dependent quantitative images of radiation intensity of a turbulent sooting ethylene flame. The flame had a Reynolds number of 15,200 and was stabilized on a burner with …