Engineering Commons^™

Quality Changes In Hermetically Stored Corn Caused By Fungi And Sitophilus Zeamais, Nda-Agyima Addae-Mensah K

Open Access Theses

Hermetic storage has been shown to be effective in controlling insect pests and maintaining grain quality of dry grains at 13% moisture and below. However, the feasibility and use of hermetic storage for grains at intermediate mid-moisture levels under the influence of the sub-Saharan African weather conditions is relatively unknown. Hermetic storage experiments were conducted on grade 1 "6297 and 6333 VT RIB" hybrid corn under controlled temperature conditions at 10 degrees centigrade and 25 degrees centigrade at target approximate moisture content levels of 11, 15, 18 and 21% wet basis for a total storage period of 6 months. Corn …

Feasibility Analysis Of Large Length-Scale Thermocapillary Flow Experiment For The International Space Station, Samantha Jean Alberts

Open Access Theses

The investigation of microgravity fluid dynamics emerged out of necessity with the advent of space exploration. In particular, capillary research took a leap forward in the 1960s with regards to liquid settling and interfacial dynamics. Due to inherent temperature variations in large spacecraft liquid systems, such as fuel tanks, forces develop on gas-liquid interfaces which induce thermocapillary flows. To date, thermocapillary flows have been studied in small, idealized research geometries usually under terrestrial conditions. The 1 to 3m lengths in current and future large tanks and hardware are designed based on hardware rather than research, which leaves spaceflight systems designers …

Feasibility Of Pulsed Proton Induced Acoustics For 3d Dosimetry, Fahed M. Alsanea

Open Access Theses

Proton therapy has the potential to deposit its energy in tissue with high conformity to the tumor and significantly reduced integral dose to normal tissue compared to conventional radiation, such as x-rays. As a result, local control can be enhanced while reducing side-effects and secondary cancers. This is due to the way charged Particles deposit their energy or dose, where protons form a Bragg peak and establish a well-defined distal edge as a function of depth (range). To date, the dose delivered to a patient from proton therapy remains uncertain, in particular the positioning of the distal edge of the …

Exploratory Study In Container Loading Embraer 190 Aircraft, Ryan H. Auyeung

Open Access Theses

Since the dawn of aviation, cargo loading on aircraft has remained virtually constant. A person and a baggage cart together have been the primary method of loading baggage on to aircraft, and this practice has virtually remained unchanged, especially for narrow body aircraft. This study explores the question of whether a loading device, designed for Embraer 190 aircraft, can increase economic efficiency by reducing aircraft turnaround times, increasing aircraft utilization and reducing work hours. In the course of designing a theoretical loading device for an Embraer 190, various literature ranging from elaborate articulating conveyor belts, to the use of LD3-45W …

Developing A Hardware Platform For A Low-Power, Low-Cost, Size-Constrained Biomechanical Telemetry System, Aditya Balasubramanian

Open Access Theses

As sport-related traumatic brain injuries face increasing attention from the media and the general public, the need to be able to detect brain injury quickly, inexpensively and accurately is more important than ever. Commercially-available event-based systems exist that claim to achieve this goal; however, they collect little to no continuous-time data and primarily indicate when a pre-determined acceleration threshold has been exceeded under the unvalidated assumption that a potentially concussive blow has occurred. Recent findings by the Purdue Neurotrauma Group (PNG) have indicated that repeated exposure to both concussive and subconcussive blows can result in cumulative trauma disorder. To track …

Detailed Finite Element Analysis And Preliminary Study Of The Effects Of Friction And Fastener Pre-Tension On The Mechanical Behavior Of Fastened Built-Up Members, Francisco Javier Bonachera Martin

Open Access Theses

The characterization of fatigue resistance is one of the main concerns in structural engineering, a concern that is particularly important in the evaluation of existing bridge members designed or erected before the development of fatigue design provisions. The ability of a structural member to develop alternate load paths after the failure of a component is known as member-level or internal redundancy. In fastened built-up members, these alternate load paths are affected by the combination of fastener pre-tension and friction between the structural member components in contact. In this study, a finite element methodology to model and analyze riveted and bolted …

Drift-Flux Correlation Development For Two-Phase Flow In Rod Bundles, Collin M. Clark

Open Access Theses

A rod bundle drift-flux correlation is developed with intended application across a wide range of two-phase flow conditions. Special consideration is made for fluid flow mechanisms at low liquid velocity and low pressure conditions. In these instances, gravitational forces from the density difference of the associated fluid phases are more significant. Secondary flow patterns may develop as a result and a drift-flux correlation would need to make appropriate adjustments. Earlier correlations may have increased error at these conditions if they have been formulated with respect to relatively higher pressures or flow rates. In the present work, area-average void fraction data …

Characteristics Of Fibrous Tissue At High Rates Of Tensile Loading, Benjamin J. Claus

Open Access Theses

The mechanical behavior of fibrous tissue is generally characterized at very low strain rates. However, many injuries occur at high rates of loading, such as those encountered in sporting events or vehicle accidents. An understanding of injury behavior requires the injury process to be recorded at high strain rates. Even at low rates of loading, the injury/failure within tissues occurs quickly. Furthermore, using conventional imaging systems, the surface of a specimen may be well documented throughout an experiment. However, damage formation does not necessarily begin at the surface of the specimen or even on the surface exposed to a camera. …

Biomechanics And Relaxivity For Functional Imaging Of Articular Cartilage Injury And Degradation, Kateri Elizabeth Fites

Open Access Theses

Osteoarthritis (OA) is a major debilitating health concern and economic burden worldwide, affecting 27 million people in the United States alone. OA often follows tissue injury, and is marked by changes in the structure and biomechanical function of cartilage, including breakdown of extracellular matrix molecules, loss of bulk tissue stiffness, and increase in articular surface friction and wear. Unlike bone and many other tissues, cartilage lacks an intrinsic capacity for regeneration. Advanced OA is typically diagnosed by patient symptoms (e.g. joint pain) and confirmed by radiographic evaluation of joint space narrowing. However, the application of functional imaging to assess cartilage …

Blast Energy Mitigation In Porous Rocks, Brittany Corinne Essink

Open Access Theses

Geo-materials are commonly used and sought after for blast mitigation applications due to their wide availability and low cost compared to industry trademarked materials. Characterization of these natural geo-materials such as volcanic rocks is of paramount importance in determining their blast mitigation capabilities. While there is a large amount of information available for materials such as concrete or sand blasts, information on the properties of volcanic rocks is far more scarce. This lack of data is due to the wide range of existing natural volcanic rocks and the variation in the minerals and pore structures of the rocks.

In this …

The Effect Of Job Performance Aids On Quality Assurance, Erik David Fosshage

Open Access Theses

Job performance aids (JPAs) have been studied for many decades in a variety of disciplines and for many different types of tasks, yet this is the first known research experiment using JPAs in a quality assurance (QA) context. The objective of this thesis was to assess whether a JPA has an effect on the performance of a QA observer performing the concurrent dual verification technique for a basic assembly task. The JPA used in this study was a simple checklist, and the design borrows heavily from prior research on task analysis and other human factors principles. The assembly task and …

Graphical Performance Measures For Practitioners To Identify Split Failures, Richard Scott Freije

Open Access Theses

Detector occupancy is commonly used to measure traffic signal performance. Despite improvements in controller computational power, there have been relatively few innovations in occupancy-based performance measures or integration with other data. This thesis introduces and demonstrates the use of graphical performance measures based on detector occupancy ratios to verify potential split failures and other signal timing shortcomings reported to practitioners by the public. The proposed performance measures combine detector occupancy during the green interval, detector occupancy during the first five seconds of the red interval, and phase termination cause (gap out or force off). These are summarized by time of …

Effectiveness Of Air Sealing Measures And Other Energy Retrofit Measures In Lafayette Energy Improvement Program, Jia Ye

Open Access Theses

From September 2011 to March 2013, the City of Lafayette, IN implemented Lafayette Improvement Program. The goal of this project was to "increase energy efficiency of existing homes through retrofitting, thereby lowering the costs of home ownership within the Vinton and Glen Acres Neighborhood Target Area (The City of Lafayette, 2011)." Energy audit companies carried out before blower door test and after blower door test to identify air tightness of subjects. This paper finds out there was an improvement in air tightness in the population of 85 houses and the degree of improvement was between 16.85% and 17.85%.

Change point …

Tunable Hyperbolic Metamaterials Utilizing Phase Change Heterostructures, Harish N.S. Krishnamoorthy, You Zhou, Shriram Ramanathan, Evgenii Narimanov, Vinod M. Menon

Birck and NCN Publications

We present a metal-free tunable anisotropic metamaterial where the iso-frequency surface is tuned from elliptical to hyperbolic dispersion by exploiting the metal-insulator phase transition in the correlated material vanadium dioxide (VO2). Using VO2-TiO2 heterostructures, we demonstrate the transition in the effective dielectric constant parallel to the layers to undergo a sign change from positive to negative as the VO2 undergoes the phase transition. The possibility to tune the iso-frequency surface in real time using external perturbations such as temperature, voltage, or optical pulses creates new avenues for controlling light-matter interaction. (C) 2014 AIP Publishing LLC.

Diversity Catalysts Involvement And Impact, Klod Kokini, Patrice M. Buzzanell, Clint Chapple, Andrew Hirsch, Kathleen Howell

ADVANCE-Purdue Gender and STEM Research Symposium

The National Science Foundation’s (NSF) ADVANCE program has funded over $130 million USD in efforts “to increase the representation and advancement of women in academic science and engineering careers, thereby contributing to the development of a more diverse science and engineering workforce” (http://www.nsf.gov/crssprgm/advance/index.jsp). The PURDUE-ADVANCE project has three major goals: 1) to increase the number and success of STEM women faculty of color; 2) to increase the success and leadership of women faculty in STEM, and 3) to educate all the faculty and in particular, the majority, about the benefits of diversity and inclusion (see http://www.purdue.edu/discoverypark/advance/). Across …

Epics: Broadening The Pathway Into Stem, Mindy Hart, Patrice M. Buzzanell, William Charles Oakes, Carla B Zoltowski

ADVANCE-Purdue Gender and STEM Research Symposium

The Engineering Projects in Community Service (EPICS) program was co-founded at Purdue University in 1995 and has since spread throughout the United States and globally with inroads into K-12 education through EPICS High. This presentation offers a synthesis of research findings and interventions gleaned from several datasets about students’ and alumni’s reported experiences with EPICS and the consequences of their participation. In particular, this presentation discusses the ways in which EPICS provides a different vantage point on the underrepresentation of women in STEM (science, technology, engineering, and math). Specifically, researchers have been tackling this issue of underrepresentation for decades with …

Appreciating Episodic Mentoring: Reconsiderations Of And Interventions For A Comprehensive Mentoring Process For Engineering Faculty, Patrice M. Buzzanell, Ziyu Long, Klod Kokini, Lindsey B. Anderson, Jennifer C. Batra

ADVANCE-Purdue Gender and STEM Research Symposium

The benefits of formal and informal mentoring systems in academe and other organizational settings are well documented. However, a third form of mentoring—known as episodic or spontaneous mentoring as well as mentoring moments—offers a different entrée point into the everyday construction of mentoring. Whereas most mentoring either focuses on one-on-one long-term relationships or group/cluster mentoring arrangements, episodic mentoring emphasizes processes, relational aspects of the mentoring experiences, multiple inputs, and individual empowerment. Based on inductive-deductive analyses of in-depth interviews and other empirical data about engineering faculty members' mentoring experiences in a mid-western university, we discuss how episodic mentoring is a way …

Navigating Pregnancy And Parenthood: Work-Family Considerations For Men And Women Graduate Students In Stem And Other Disciplines, Ziyu Long, Patrice M. Buzzanell, Abigail Selzer King

ADVANCE-Purdue Gender and STEM Research Symposium

Scholars and non-academicians consider popular key advantages to be flexibility in career trajectories as well as autonomy and control over one’s schedule and the work that one chooses to do (e.g., Buzzanell & Lucas, 2006, 2013). Although academic careers seem to offer these benefits, there are questions about whether and how such flexibility actually occurs, particularly in times of pregnancy/adoption, family leave, and work-life “balance” (e.g., Stone, 2008). Implicit in academic flexibility is that graduate student careers might evidence some of the same flexibility but within institutional structures that can range from lockstep to a build-you-own-plan and timetable model. In …

Laser Sintering Of Separated And Uniformly Distributed Multiwall Carbon Nanotubes Integrated Iron Nanocomposites, Dong Lin, Chunghorng Richard Liu, Gary J. Cheng

Birck and NCN Publications

Uniform distribution of carbon nanotubes (CNTs) in metal matrix during additive manufacturing of nanocomposites is always a challenge since the CNTs tend to aggregate in the molten pool. In this study, Multiwall carbon nanotubes (MWNTs) were separated and distributed uniformly into iron matrix by laser sintering process. MWNTs and iron powders were mixed together by magnetic stir, coated on steel 4140 surface, followed by laser sintering. Due to the fast heating and cooling rate, the CNTs are evenly distributed in the metal matrix. The temperature field was calculated by multiphysics simulation considering size effects, including size dependent melting temperature, thermal …

Nu=5/2 Fractional Quantum Hall State In The Presence Of Alloy Disorder, Nianpei Deng, Geoff C. Gardner, Sumit Mondal, Ethan Kleinbaum, Michael J. Manfra, Gabor Csathy

Birck and NCN Publications

We report quantitative measurements of the impact of alloy disorder on the. nu = 5/2 fractional quantum Hall state. Alloy disorder is controlled by the aluminum content x in the AlxGa1-xAs channel of a quantum well. We find that the nu = 5/2 state is suppressed with alloy scattering. To our surprise, in samples with alloy disorder the nu = 5/2 state appears at significantly reduced mobilities when compared to samples in which alloy disorder is not the dominant scattering mechanism. Our results highlight the distinct roles of the different types of disorder present in these samples, such as the …

Electrical And Thermal Conductivities Of Reduced Graphene Oxide/Polystyrene Composites, Wonjung Park, Jiuning Hu, Luis A. Jauregui, Xiulin Ruan, Yong P. Chen

Birck and NCN Publications

The author reports an experimental study of electrical and thermal transport in reduced graphene oxide (RGO)/polystyrene (PS) composites. The electrical conductivity (sigma) of RGO/PS composites with different RGO concentrations at room temperature shows a percolation behavior with the percolation threshold of similar to 0.25 vol. %. Their temperature-dependent electrical conductivity follows Efros-Shklovskii variable range hopping conduction in the temperature range of 30-300K. The thermal conductivity (kappa) of composites is enhanced by similar to 90% as the concentration is increased from 0 to 10 vol. %. The thermal conductivity of composites approximately linearly increases with increasing temperature from 150 to 300 …

Understanding The Global Energy Crisis, Eugene D. Coyle, Richard A. Simmons

Purdue University Press Books

We are facing a global energy crisis caused by world population growth, an escalating increase in demand, and continued dependence on fossil-based fuels for generation. It is widely accepted that increases in greenhouse gas concentration levels, if not reversed, will result in major changes to world climate with consequential effects on our society and economy. This is just the kind of intractable problem that Purdue University’s Global Policy Research Institute seeks to address in the Purdue Studies in Public Policy series by promoting the engagement between policy makers and experts in fields such as engineering and technology.

Major steps forward …

Post-Fracture Capacity Of Railroad Flat Car Bridges, Teresa L. Washeleski

Purdue Road School

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 …

Ada Focused Construction Inspection, Erik Seef, Eryn Fletcher

Purdue Road School

This presentation will introduce inspection guidelines for field staff to implement in inspecting projects with pedestrian facilities, including curb ramps and pedestrian signals. Review of new INDOT curb standards and requirements for accessible pedestrian signals will be included. These recent changes in standards will impact projects and thus it is imperative to advise field staff of what they should be looking for with regard to width and slopes on pedestrian access routes and pedestrian push buttons. Several issues have been noted in the field, including excessive cross slope and running slope, installation of fingertip-actuated push buttons, and substandard level landings …

Road Safety Audits, Henry Brown

Purdue Road School

A Road Safety Audit (RSA) is a formal review of an existing or proposed road segment or intersection by an independent, multi-disciplinary team. The purpose of an RSA is to identify safety concerns and suggest possible countermeasures to the project owner. There are several benefits to conducting RSAs, including increased awareness of safety and a reduction in the number of crashes. The RSA process includes 8 steps during which the RSA team develops a list of findings and presents them to the project owner for consideration. The RSA process for an existing facility includes a field review during which the …

Drilled Shaft Design & Construction-Integrity Testing Issues, Mir A. Zaheer, David Latka

Purdue Road School

This presentation will provide an overview of the design and construction of drilled shafts in Indiana, including construction monitoring issue, discussion of CSL, PIT and TIP testing, and comparisons with cores taken.

Post-Failure Capacity Of Built-Up Steel Members, Matthew H. Hebdon

Purdue Road School

Mechanically fastened built-up steel members have long been known to possess internal member redundancy and, as a result, multiple load paths which can be exploited to increase their functional life. Internal redundancy provides the ability to resist total member failure in the event of a fracture of an individual component. However, there is little experimental data in the literature regarding post-fracture capacity in terms of strength and subsequent fatigue life. The experimental study currently underway will provide needed information on parameters that affect the ability of built- up members to arrest a fracture as well as the available remaining fatigue …

2014 Road School, Kevin M. Hetrick

Purdue Road School

At the 2014 Road School, this presentation focused on the proposed sliding of the Milton-Madison Bridge, a 15000 ton truss superstructure intended to move laterally 55 feet from a temporary location onto permanent piers. The project was a joint procurement between INDOT and KYTC, with a Design/Build team consisting of Walsh Construction, Buckland and Taylor, and Burgess and Niple performing the slide. The presentation was in early March, with the slide scheduled for later in the month. The slide will be the largest of its kind.

Ada Prowag Status And Common Issues/Solutions, Stephen G. Metzer Aicp, Pws

Purdue Road School

The Proposed Accessibility Guidelines for Pedestrian facilities in the Public Right-of-Way (aka PROWAG), dated July 26, 2011, went through an extensive public comment period that ended in early 2012. The Access Board anticipates issuing final guidance that will be the enforceable standard for facilities in the public ROW. This presentation will provide the latest status of the guidelines and present common problems and creative solutions.

Most Common Errors For Ada Ramp Construction, Stephen G. Metzer Aicp, Pws

Purdue Road School

Curb ramps are essential for persons with disabilities to traverse pedestrian facilities, allowing them to get from street level to the sidewalk. Errors that occur during the construction of curb ramps can result in ramps that are non-compliant with the Americans with Disabilities Act (ADA) guidelines. This presentation will include examples of common sidewalk construction errors and offer ways that project engineers can assess existing ramps to identify cases where additional design assistance may be required.