Engineering Commons^™

Quantification Of Intervertebral Disc Strain From High-Resolution Ultrasound Imaging During Dynamic Loading, Diya Sakhrani

Discovery Undergraduate Interdisciplinary Research Internship

High-resolution ultrasound imaging employs high-frequency sound waves that can be used to noninvasively visualize the structures within the body, facilitating medical diagnosis without the need for open surgery. The widespread utilization of ultrasound is attributed to its affordability, non-invasive characteristics, and use of non-ionizing radiation. Nevertheless, ultrasound is prone to artifacts originating from the surrounding environment, gas-liquid interfaces, or dense tissue. These artifacts are common in ultrasound images and can cause dropout, noise, and degraded resolution. In this study we analyzed intervertebral disc (IVD) strain during two axial compression testing cycles of bovine intervertebral discs with a 2-dimensional direct deformation …

Measuring Gas Discharge In Contact Electrification, Hongcheng Tao, James Gibert

Purdue University Libraries Open Access Publishing Fund

Contact electrification in a gas medium is usually followed by partial surface charge dissipation caused by dielectric breakdown of the gas triggered during separation of the surfaces. It is widely assumed that such discharge obeys the classical Paschen’s law, which describes the general dependence of the breakdown voltage on the product of gas pressure and gap distance. However, quantification of this relationship in contact electrification involving insulators is impeded by challenges in nondestructive in situ measurement of the gap voltage. The present work implements an electrode-free strategy for capturing discrete discharge events by monitoring the gap voltage via Coulomb force, …

Characterizing Intervertebral Disc Strain Under Dynamic Loading Conditions Using Ultrasound Texture Analysis, Radhika Kulkarni

Discovery Undergraduate Interdisciplinary Research Internship

Herniated discs in the spine are a significant patient burden, with potential links to lower back and leg discomfort and a considerable impact on daily life. These discs, located between spinal vertebrae, are comprised of the annulus fibrosus (AF) and the nucleus pulposus (NP). Herniations happen when the NP protrudes through a full-thickness annular tear, possibly compressing spinal nerves. The mechanical factors underlying herniated discs are poorly understood, necessitating research into these mechanisms and accessible diagnostic techniques. Our study employs high-resolution ultrasound and texture correlation to quantify strain patterns in intervertebral discs during dynamic loading.

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Closing The Gap: Leveraging Aes-Ni To Balance Adversarial Advantage And Honest User Performance In Argon2i, Nicholas Harrell, Nathaniel Krakauer

CERIAS Technical Reports

The challenge of providing data privacy and integrity while maintaining efficient performance for honest users is a persistent concern in cryptography. Attackers exploit advances in parallel hardware and custom circuit hardware to gain an advantage over regular users. One such method is the use of Application-Specific Integrated Circuits (ASICs) to optimize key derivation function (KDF) algorithms, giving adversaries a significant advantage in password guessing and recovery attacks. Other examples include using graphical processing units (GPUs) and field programmable gate arrays (FPGAs). We propose a focused approach to close the gap between adversarial advantage and honest user performance by leveraging the …

Robust Design And Best Control Channel Selection Of Facts-Based Wadc For Improving Power System Stability Using Grey Wolf Optimizer, Iraj Faraji Davoudkhani, Mahmoud Rerza Shakarami, Almaotaz Y. Abdelaziz, Adel El-Shahat

Purdue University Libraries Open Access Publishing Fund

With recent advances in wide-area measurement systems (WAMS), wide-area damping controllers (WADCs) based on remote signals can effectively damp inter-area oscillations. However, these signals are inherently subjected to communication time-delay which may adversely affect the damping of inter area oscillations. The purpose of this paper is to present a optimization-based method for designing a WADC for a static synchronous series compensator (SSSC) to improve the damping of inter-area oscillations by considering the time delays of remote control signals. For this aim, the control gain value of the WADC, shifting of the critical modes to a desirable area, and the maximum …

The Effects Of Engineering Summer Camps On Middle And High School Students’ Engineering Interest And Identity Formation: A Multi-Methods Study, Timothy Robinson, Adam Kirn, Jenny Amos, Indira Chatterjee

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

This multi-methods study explores changes in engineering interest and identity of middle and high school students (n = 79) attending introductory-level engineering summer camps at a large western land grant university. Middle school is a critical time when student interest, identity, and subsequently career choice begin to emerge and hence it is important that at this age students are given accurate information about engineering majors in college and future career opportunities in engineering. Data were collected over a period of two years in six summer camps. Three separate populations of middle and high school students participated in the summer …

Mixed Reality: A Tool For Investigating The Complex Design And Mechanisms Of A Mechanically Actuated Digital Pump, Israa Azzam, Keith Pate, Farid Breidi, Minsoo Choi, Yeling Jiang, Christos Mousas

Purdue University Libraries Open Access Publishing Fund

Digital hydraulics is a discrete technology that integrates advanced dynamic system controls, digital electronics, and machine learning to enhance fluid power systems’ performance, overall efficiency, and controllability. A mechanically actuated inline three-piston variable displacement digital pump was previously proposed and designed. The inline three-piston pump incorporates complex mechanical and hydraulic subsystems and highly coupled mechanisms. The complexity of the utilized subsystems poses challenges when assessing the viability of the conceptual design. Therefore, this work focuses on designing, developing, and implementing a collaborative virtual platform involving a digitized module showcasing the internal mechanical structure of the digital pump utilizing mixed reality …

Comparative Evaluation Of Investigation Methods For Estimating The Load-Dependent State Of Charge And End Of Discharge Of A Multirotor Uav Battery, Hanna Dibbern, Morten Roßberg, Claudia Werner

Journal of Aviation Technology and Engineering

As the scope of multirotor unmanned aerial vehicle (UAV) applications increases, more attention is being paid to UAV energy requirements, which vary depending on the mission profile. To obtain accurate information about the UAV battery during flight, the idea of a digital twin including a battery state estimation model is promising. For battery state estimation, a Kalman filter combination is the preferred approach in the literature. Comparing different Kalman filters, the unscented Kalman filter has a more accurate estimation for nonlinear systems compared to the extended Kalman filter. In the application of UAV flight with load-dependent flight missions, the comparison …

Challenging The Notion Of Role Models In Engineering Outreach Programs For Youth, Kelli M. Paul, Karen Miel, Merredith D. Portsmore, Adam Maltese

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

Engineering outreach programs often portray outreach educators as role models for youth. It is widely believed that introducing youth, especially girls, to potential engineering role models will broaden participation in engineering majors and careers. Based on interviews with and surveys of fourth- and fifth-grade girls participating in an engineering outreach program, we question whether youth are looking for career role models, and we challenge the assumption that youth will take up an adult as a role model simply because the adult is presented as such. We question what role these ‘‘models’’ play in the minds and lives of youth and …

Tellurium Corrosion Of Type 304/304l Stainless Steel, Iron, Chromium, And Nickel In High-Temperature Liquid Sodium, Yi Xie

Purdue University Libraries Open Access Publishing Fund

Investigating tellurium (Te) corrosion on structural materials is crucial for sodium-cooled fast reactors (SFRs) due to radionuclide presence and knowledge gaps. In this study, Type 304/304L stainless steel (SS304), chromium (Cr), iron (Fe), and nickel (Ni) samples were immersed in low-oxygen environments with Te in liquid sodium at 773 K for 30 days. At 10 ppm oxygen, SS304 showed multiple oxide layers, including a compact NaCrO2 interlayer and porous Na-Fe-Ni-O outer layers. Tellurium penetrated through the porous layers but was hindered by the NaCrO2 interlayer. At 0.01 ppm oxygen, Cr had no oxide layer, while Fe and Ni had unstable …

Vistac Toward A Unified Multimodal Sensing Finger For Robotic Manipulation, Sheeraz Athar, Gaurav Patel, Zhengtong Xu, Qiang Qiu, Yu She

School of Industrial Engineering Faculty Publications

Tactile sensors are crucial in providing contact geometry information necessary for object manipulation. However, it remains highly nontrivial for a tactile sensor to be able to perceive a distant object before manipulation. In this work, we present an innovative robotic finger, VisTac, which seamlessly combines high-resolution tactile and visual perception in a single unified device, while adhering to essential mechanical constraints, such as a human-finger-like wedge-shaped top, vital for manipulation tasks. Furthermore, we discuss the fabrication of a key component in the device; the semitransparent membrane with light-dependent opacity, thus enabling the contact surface to effortlessly transition between visual and …

A Positioning Theory Analysis Of Interaction Surrounding Design Failures In An Elementary Engineering Club, Katarina N. Silvestri, Mary B. Mcvee, Lynn E. Shanahan, Kenneth English

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

This qualitative study applies Positioning Theory to identify positions that mediate the experiences of design failure within the context of an afterschool engineering club (EC) with elementary students diverse in language, race, ethnicity, gender, and academic abilities. We ask: (1) What kinds of structural design failure and failure responses did participants in EC experience? and (2) What are students’ and teachers’ positions in relation to responses to design failure? Types of positions (e.g., builder, tinkerer, idea-elicitor, director, observer) were identified in relation to children’s and teachers’ actions and speech in response to structural design failure during EC. Participants included 12 …

Streamlined Hpc Environments With Cvmfs And Cybergis-Compute, Alexander C. Michels, Mit Kotak, Anand Padmanabhan, Shaowen Wang

I-GUIDE Forum

High-Performance Computing (HPC) resources provide the potential for complex, large-scale modeling and analysis, fueling scientific progress over the last few decades, but these advances are not equally distributed across disciplines. Those in computational disciplines are often trained to have the necessary technical skills to utilize HPC (e.g. familiarity with the terminal), but many disciplines face technical hurdles when trying to apply HPC resources to their work. This unequal familiarity with HPC is increasingly a problem as cross-discipline teams work to tackle critical interdisciplinary issues like climate change and sustainability. CyberGIS-Compute is middle-ware designed to democratize to HPC services with the …

Towards Carbon-Aware Spatial Computing: Challenges And Opportunities, Bharat Jayaprakash, Matthew Eagon, Mingzhou Yang, William F. Northrop, Shashi Shekhar

I-GUIDE Forum

Carbon-aware spatial computing (CASC) is focused on reducing the carbon footprint of spatial computing itself and leveraging spatial computing techniques to minimize carbon emissions in other domains. The significance of CASC lies in its potential to mitigate anthropogenic climate change by offering numerous societal applications, such as carbon-aware supply chain development and carbon-aware site selection. CASC is challenging because of the spatiotemporal variability and the high dimensionality of carbon emissions data, involving spatial coordinates and timestamps. Related work, known as carbon-aware computing, mostly focuses on job scheduling of cloud computing, and there is a lack of surveys and review papers …

Fine Tuning Mobilenet Neural Networks For Oil Spill Detection, Caixia Wang, Andrew Coulson

I-GUIDE Forum

The monitoring of open water and early identification of oil spills in the Alaska Arctic has become increasingly critical due to the rise in oil and gas exploration and shipping activities, facilitated by the increasing number of ice-free days resulting from global warming. This escalating risk of oil spills is further compounded by potential accidents in offshore operations, illicit oil discharges, and knowledge gaps in Arctic coastlines, rapidly changing due to rising seas, permafrost melting, and coastal erosion. To address these pressing challenges, we propose a deep learning model based on MobileNet neural networks to detect oil spills in remotely …

I-Guide Climbers: A Model For Multidisciplinary Academic Labs For Early Career Development, Iman Haqiqi, Wei Hu, Ramya Kumaran, Pin-Ching Li, Nicholas Manning, Alex Michels, Ayman Nassar, Jinwoo Park, Jimeng Shi, Adam Tonks, Zhaonan Wang

I-GUIDE Forum

In this paper, we propose a new form of multidisciplinary academic collaboration that goes beyond the traditional modes of knowledge exchange. We argue that most research collaboration today is based on interactions between closely related disciplines, in which researchers share data, methods, and insights within a common framework or problem. However, such collaboration may not foster the development of the communication and management skills essential to a multi-disciplinary research career. Therefore, we suggest establishing a network of researchers from divergent, yet complementary, disciplines who are interested in improving these skills through regular interactions and feedback. The main goal of this …

Reducing Uncertainty In Sea-Level Rise Prediction: A Spatial-Variability-Aware Approach, Subhankar Ghosh, Shuai An, Arun Sharma, Jayant Gupta, Shashi Shekhar, Aneesh Subramanian

I-GUIDE Forum

Given multi-model ensemble climate projections, the goal is to accurately and reliably predict future sea-level rise while lowering the uncertainty. This problem is important because sea-level rise affects millions of people in coastal communities and beyond due to climate change's impacts on polar ice sheets and the ocean. This problem is challenging due to spatial variability and unknowns such as possible tipping points (e.g., collapse of Greenland or West Antarctic ice-shelf), climate feedback loops (e.g., clouds, permafrost thawing), future policy decisions, and human actions. Most existing climate modeling approaches use the same set of weights globally, during either regression or …

A New Empirical Law For The Prediction Of The Zero-Lift Pitching Moment Coefficient Of Swept And Tapered Wings, Mondher Yahyaoui

Journal of Aviation Technology and Engineering

A new empirical law for the prediction of the zero-lift pitching moment coefficient of trapezoidal wings with linear twist and constant taper and sweep in subsonic flow is introduced. This law is quite general in that it does not rely on the use of charts and spans the normal range of values of taper ratio, aspect ratio, and sweep for subsonic aircraft. It does not, however, accommodate different airfoils along the wingspan and only positive sweep has been considered. The empirical law was first derived for the incompressible regime and then an additional empirical law for the compressibility effect has …

Spin-Acoustic Control Of Silicon Vacancies In 4h Silicon Carbide, Jonathan R. Dietz, Boyang Jiang, Aaron M. Day, Sunil A. Bhave, Evelyn L. Hu

Purdue University Libraries Open Access Publishing Fund

Bulk acoustic resonators can be fabricated on the same substrate as other components and can operate at various frequencies with high quality factors. Mechanical dynamic metrology of these devices is challenging as the surface information available through laser Doppler vibrometry lacks information about the acoustic energy stored in the bulk of the resonator. Here we report the spin-acoustic control of naturally occurring negatively charged silicon monovacancies in a lateral overtone bulk acoustic resonator that is based on 4H silicon carbide. We show that acoustic driving can be used at room temperature to induce coherent population oscillations. Spin-acoustic resonance is shown …

A Qualitative Ethnographic Case Study Exploring The Hispanic/Latinx Interpretations Of Collegiate Aviation Safety Culture, Jorge L. D. Albelo Ph.D., Leo G. Acosta, Flavio A. C. Mendonca Ph.D., Eugene Kim, Felipe Almodovar

Journal of Aviation Technology and Engineering

Through a combination of ethnographic principles and a qualitative case study structure, this study strives to understand how Hispanic/ Latinx aviation students perceive the current aviation safety culture in their flight training program. Grounded in the reciprocal safety culture model, the researchers attempt to answer how does Hispanic/Latinx culture influence perceptions towards commitment to aviation safety? and what are Hispanic/Latinx students’ perceptions of their ability to influence aviation safety culture? Three major themes emerged from the data: behavioral signs of safety culture at the collegiate level, obstacles to a sound safety culture, and methods to improve the safety culture. Moreover, …

An Analysis Of Aerodynamic Design Issues Of Box-Wing Aircraft, Paul Jemitola, Paul Okonkwo

Journal of Aviation Technology and Engineering

The potential of the joined/box-wing aircraft as an environmentally friendly airliner that is capable of meeting current and future emission thresholds led to the investigation of this concept. This study reviews the evolution and current trends in the aerodynamic design of the box-wing aircraft with specific emphasis on box-wing theory, airfoil characteristics, and aerodynamic issues of the box-wing aircraft. The study was undertaken to highlight the distinct features of the box-wing configuration which make it very attractive for future airliners. The study reveals that the box-wing aircraft possesses a significant aerodynamic advantage over conventional aircraft. The box-wing aircraft configuration is …

Eipeck: Assessing Educators’ Pedagogical Content Knowledge For Engineering Integration In K-12, Pilar Pazos, Francisco Cima Cohuo, Jennifer Kidd, Kristie Gutierrez, Krishnanand Kaipa, Orlando Ayala

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

Global efforts are underway to include engineering in pre-college curricula. In the USA, this pursuit led to the inclusion of engineering content in the most recent version of the Next Generation Science Standards that guide K-12 science. As these standards become part of the K-12 curriculum, teachers face the challenge of gaining basic engineering literacy, while developing the associated inclusive pedagogies necessary to integrate engineering content into their classrooms. In this context, teacher preparation programs can benefit from easy-to-implement tools that measure preservice teachers’ readiness to integrate engineering content in their future classrooms. This work describes the development and validation …

A General Effectiveness-Ntu Modeling Framework For Membrane Dehumidification Systems, Andrew J. Fix, James E. Braun, David M. Warsinger

School of Mechanical Engineering Faculty Publications

Selective membrane dehumidification is a promising technology for energy efficient air dehumidification in buildings and has been ranked as a top alternative technology by the Department of Energy. One critical area that needs to be addressed is system modeling that incorporates device mass transfer characteristics and sizing. This work develops, validates, and applies a simple effectiveness-number of transfer units (𝜀−𝑁TU) modeling framework for dehumidification technologies that can be used to predict performance and determine required membrane area for a wide range of technologies, including energy recovery ventilators, vacuum membrane dehumidification, and desiccant dehumidifiers. Although the 𝜀−𝑁TU method is a well-established …

An Object-Based Ground Filtering Of Airborne Lidar Data For Large-Area Dtm Generation, Hunsoo Song, Jinha Jung

Purdue University Libraries Open Access Publishing Fund

Digital terrain model (DTM) creation is a modeling process that represents the Earth’s surface. An aptly designed DTM generation method tailored for intended study can significantly streamline ensuing processes and assist in managing errors and uncertainties, particularly in large-area projects. However, existing methods often exhibit inconsistent and inexplicable results, struggle to clearly define what an object is, and often fail to filter large objects due to their locally confined operations. We introduce a new DTM generation method that performs object-based ground filtering, which is particularly beneficial for urban topography. This method defines objects as areas fully enclosed by steep slopes …

Extreme Cooling Via Sweeping Gas Membrane Distillation, David M. Warsinger

School of Mechanical Engineering Faculty Publications

Thermal desalination processes like membrane distillation (MD) aim to have rapid evaporation rates to provide large quantities of fresh water. These processes, which resemble counterflow-heat exchangers with membranes in the middle, conventionally seek to maximize vapor mass transfer while minimizing all other modes of heat transfer as “thermal losses.” However, we can reverse this fundamental design need to make an exceptionally high throughput heat dissipation device. By using thin thermally conductive membranes and extremely rapid air flow rates, membrane heat exchangers inspired by MD can dissipate heat several times faster than conventional air-cooled heat exchangers. We demonstrate this new approach …

Mechanochemical Esterification Of Cellulose Nanofibers Lyophilized From Eutectic Water–Tert-Butanol Mixtures, Miran Mavlan, Taehoo Chang, Rudan Feng, Jake R. Wilkinson, Robert J. Nicholas, Nosa B. Idahagbon, Jeffrey Youngblood, Alexander Wei

Department of Chemistry Faculty Publications

Freeze-dried CNFs can be modified by mechanochemical (MC) processes with minimal use of auxiliary solvents, however aggregation of nanofibers during lyophilization compromises their granularity and reaction efficiency. Adding 10 wt% tert-butanol (TBA) to aqueous slurries of wood-derived CNF creates a eutectic mixture that reduces hornification during lyophilization, resulting in well-formed aerogels with minimal shrinkage in volume. CNFs lyophilized from mixtures containing at least 10 wt% TBA exhibit an order of magnitude increase in specific surface area relative to CNFs freeze-dried from water alone. The amount of TBA and input energy needed for lyophilization can be reduced considerably by dewatering …

On The Design And Power Output Response Of Hydraulic Wind Turbines, Helber Antonio Esquivel-Puentes, Andrea Vacca, Venkatesh Pulletikurthi, Ali Doosttalab, Jose Garcia-Bravo, David M. Warsinger, Leonardo P. Chamorro, Luciano Castillo

School of Mechanical Engineering Faculty Publications

Standard horizontal axis wind turbines typically use gearboxes for large-scale applications and direct coupling for small-scale designs to connect the rotor to the generator. However, gearboxes pose challenges due to their weight, cost, and exposure to dynamic loads and vibrations within the nacelle. A promising alternative is replacing mechanical transmission with a hydrostatic counterpart, offering advantages such as reduced nacelle mass, generator placement at the tower base, and elimination of the gearbox. It can potentially lead to cost savings of up to 20% in the levelized cost of electricity for offshore wind turbines. This study compares regulated hydrostatic transmission with …

Course Experiences That Promote And Inhibit Human-Centered Design, Elizabeth A. Sanders, Molly Goldstein, Justin L. Hess

School of Engineering Education Faculty Publications

Engineers contribute to large-scale socio-technical challenges, and human-centered design offers a design thinking approach that helps engineers develop a thorough understanding of the socio-technical effects of their design work. Thus, effective strategies for assessing and teaching human-centered design are needed. This study aimed to identify course characteristics that influence how students experience human-centered design in an introductory systems engineering design course. First, we categorized open-ended written reflections to understand the degree to which students experienced human-centered design. Second, we performed a thematic analysis to characterize salient course experiences for two groups of students: (1) students who experienced human-centered design in …

Dielectric/Impedance Spectroscopy For In-Line Measurement Of Moisture Content, Sophie Zhou

Discovery Undergraduate Interdisciplinary Research Internship

Pharmaceutical production requires strict moisture content control in order to ensure quality, stability, and efficacy of medicinal products. Moisture content can be manually tested but a rapid and reliable solution for real-time moisture content monitoring was necessary to improve overall efficiency in pharmaceutical manufacturing. This research delved into the practicality of using electrochemical impedance spectroscopy (EIS) as a dependable technique to determine moisture content. By investigating the electrical properties of materials, we established a robust connection between shifts in electrical properties with variations in moisture levels. We employed an equivalent circuit model to unveil the underlying mechanism which provided valuable …

Scanning Electron Microscopy Analysis Of Murine Renal, Aortic, And Cardiac Tissue, Sarah E. Grev, Luke E. Schepers, Jennifer Anderson, Craig J. Goergen

Discovery Undergraduate Interdisciplinary Research Internship

Scanning electron microscopy (SEM) is a tool that provides detailed insight into objects invisible to the human eye. As the name suggests, an electron beam is used to create an image down to the nanometer scale. The beam focuses on the surface of a sample using lenses in the electron column. In this project, we use SEM to study three types of murine tissue. First, we examine the glomerulus, found in the kidney, that is primarily responsible for filtering blood. Following a left renal vein (LRV) stenosis, SEM is used to observe changes to the glomeruli. Differences in the left …