Engineering Commons^™

Semcache: Semantics-Aware Caching For Efficient Gpu Offloading, Nabeel Al-Saber

Open Access Dissertations

Graphical Processing Units (GPUs) offer massive, highly-efficient parallelism, making them an attractive target for computation-intensive applications. However, GPUs have a separate memory space which introduces the complexity of manually handling explicit data movements between GPU and CPU memory spaces. Although GPU kernels/libraries have made it easy to improve application performance by offloading computation to GPUs, unfortunately it is very difficult to manually optimize CPU-GPU communication between multiple kernel invocations to avoid redundant communication when using these kernels with complex applications. ^ In this thesis, we introduce SemCache, a semantics-aware GPU cache that automatically manages CPU-GPU communication in addition to optimizing …

Photochemistry Of Single-Walled Carbon Nanotubes In The Aquatic Environment, And Their Extraction From Soils, Somayeh Beigzadehmilani

Open Access Dissertations

Carbon nanotubes (CNTs) are a class of engineered nanoparticles, composed of an array of sp2 carbon atoms arranged as fused benzene rings. Due to their exceptional electrical, mechanical, and physical properties, CNTs find applications in construction, aerospace, and medical industries. In the United States, CNTs already had an annual production of 2,000 tons in 2011. This rate of annual production indicates that CNTs will find their way into the environment, which will result in certain environmental exposure. Yet, there have not been sufficient and definitive studies on the health and environment effects of CNTs. For example, additional information regarding environmental …

Modular Approach To Spintronics, Kerem Yunus Camsari

Open Access Dissertations

There has been enormous progress in the last two decades, effectively combining spintronics and magnetics into a powerful force that is shaping the field of memory devices. New materials and phenomena continue to be discovered at an impressive rate, providing an ever-increasing set of building blocks that could be exploited in designing transistor-like functional devices of the future. The objective of this thesis is to provide a quantitative foundation for this building block approach, so that new discoveries can be integrated into functional device concepts, quickly analyzed and critically evaluated. Through careful benchmarking against available theory and experiments we establish …

Behavior And Design Of Steel-Plate Composite (Sc) Walls For Blast Loads, Jakob C Bruhl

Open Access Dissertations

Reinforced concrete (RC) structures have historically been the preferred choice for blast resistant structures because of their mass and the ductility provided by steel reinforcement. Steel-plate composite (SC) walls are a viable alternative to RC for protecting the infrastructure against explosive threats. SC structures consist of two steel faceplates with plain concrete core between them. The steel faceplates are anchored to the concrete using stud anchors and connected to each other using tie bars. SC structures provide mass from the concrete infill and ductility from the continuous external steel faceplates. This dissertation presents findings and recommendations from experimental and analytical …

Circular Bessel Field Statistics And The Pursuit Of Far-Subwavelength Resolution, Yulu Chen

Open Access Dissertations

The statistical description of wave propagation in random media is important for many applications. While polarized light in systems with weakly interacting scatterers and sufficient overall scatter has zero-mean circular Gaussian statistics, the underlying assumptions break down in the Anderson localization and weakly scattering regimes. Although probability density functions for wave intensity and amplitude exist beyond Gaussian statistics, suitable statistical descriptions for the field with strong and weak random scatter were unknown. The first analytical probability density function for the field that is effective in both the Anderson localization regime and the weakly scattering regime is derived by modeling the …

Experimental And Modeling Investigation Of Cellulose Nanocrystals Polymer Composite Fibers, Si Chen

Open Access Dissertations

Cellulose nanocrystals (CNCs) are a class of newly developed and sustainable nanomaterial derived from cellulose-based materials such as wood. There have been substantial research efforts to utilize these materials as reinforcing agents. However, in order to develop CNC nanocomposites with industrial applications, it is necessary to understand how addition of CNCs affect the properties of the polymer nanocomposite. In the present work, several approaches, experimental and theoretical, are presented in an effort to characterize and understand the effect of CNCs on the properties of polymer CNC fibers. ^ Two experimental methods were used to develop cellulose acetate (CA) and CNC …

Near-Inertial Internal Poincare Waves In Lake Michigan: Seasonal Variability And Effects On Lateral Dispersion And Turbulent Mixing, Jun M Choi

Open Access Dissertations

A dominant physical process in stratified Lake Michigan is near-inertial internal Poincaré waves. The near-inertial internal Poincaré waves is described as locally quasi-uniform currents in the lateral direction, with vertically-sheared structures rotating clockwise at a near-inertial period. The goal of this dissertation is to investigate their seasonal variation and the potential roles on lateral dispersion and vertical mixing. ^ At this mid-lake location, the Poincaré wave is seen to describe more than 80% of the observed surface current variability for much of the year, with characteristic near-inertial frequency and clockwise-rotating velocities. The wave persists during the stratified period, and is …

Modeling Person-To-Person Contaminant Transport In Enclosed Environments, Chun Chen

Open Access Dissertations

It is essential to predict person-to-person contaminant transport in enclosed environments to improve air distribution design and reduce the infection risk from airborne infectious diseases. This study aims to improve and accelerate the simulation of person-to-person contaminant transport in enclosed environments. ^ This investigation first conducted experimental measurements of person-to-person contaminant transport in an office mockup and the first-class cabin of a functional MD-82 aircraft. The experimental data of steady-state airflow, temperature, and gas contaminant concentration fields obtained in the office were used to validate the steady-state computational fluid dynamics (CFD) models. In the aircraft cabin, the transient particle concentrations …

Difficulty As A Concept Inventory Design Consideration: An Exploratory Study Of The Concept Assessment Tool For Statics (Cats), Dana L. Denick

Open Access Dissertations

The ability for engineering students to apply mathematic, scientific and engineering knowledge to real-life problems depends greatly on developing deep conceptual knowledge that structures and relates the meaning of underlying principles. Concept inventories have emerged as a class of tests typically developed for use in higher education science and engineering courses. Concept Inventories (CIs) are multiple-choice tests that are designed to assess students' conceptual understanding within a specific content domain. For example, the CI explored within this study, the Concept Assessment Tool for Statics (CATS) is intended to measure students' understanding of the concepts underlying the domain of engineering statics. …

Tunable Organization Of Cellulose Nanocrystals For Controlled Thermal And Optical Response, Jairo A. Diaz Amaya

Open Access Dissertations

The biorenewable nature of cellulose nanocrystals (CNCs) has opened up new opportunities for cost-effective, sustainable materials design. By taking advantage of their distinctive structural properties and self-assembly, promising applications have started to nurture the fields of flexible electronics, biomaterials, and nanocomposites. CNCs exhibit two fundamental characteristics: rod-like morphology (5-20 nm wide, 50-500 nm long), and lyotropic behavior (i.e., liquid crystalline mesophases formed in solvents), which offer unique opportunities for structural control and fine tuning of thermal and optical properties based on a proper understanding of their individual behavior and interactions at different length scales. In the present work, we attempt …

Unveiling The Mechanical Behavior Of The Rod-Like Microstructure In The Radular Teeth Of Cryptochiton Stelleri, Enrique Escobar De Obaldia

Open Access Dissertations

Natural ceramics provided with high volume fractions of mineralized materials that are surrounded by a weak organic interface combine the stiff mechanical behavior of building blocks, like hydroxyapatite or aragonite, and the compliance of the organic surroundings. Unique mechanical properties (e.g. light density and toughness) distinguish bio-composites from common engineering materials. A key example is the highly mineralized shell of the radular teeth of the Crypochiton stelleri. Nature has provided the radular teeth with a highly oriented rod-like microstructure of nano-scale dimensions embedded in a matrix of chitin sheaths. Compared to other biological materials, the external iron oxide layer of …

International Water And Food Security Development: Performance Evaluation And Assessment Of Research Needs At Multiple Scales, Caitlin Anne Grady

Open Access Dissertations

Water and food security remain the top development challenges of the decade, and perhaps the century. Since the Millennium Development Goals were established in 2000, billions of people have obtained access to more food, better nutrition, improved water, and basic sanitation facilities worldwide. This progress has been accomplished through the dedication of international organizations, non-governmental organizations, country-level governments, private corporations, and individuals at international, regional, and local scales. Truly tremendous strides have been made in water and food provisioning for humans worldwide. These past two decades have also seen the largest population growth on record, the highest rates of childhood …

Control Of Modular Multilevel Converters For Grid Integration Of Full-Scale Wind Energy Conversion Systems, Suman Debnath

Open Access Dissertations

The growing demand for wind power generation has pushed the capacity of wind turbines towards MW power levels. Higher capacity of the wind turbines necessitates operation of the generators and power electronic conversion systems at higher voltage/power levels. The power electronic conversion system of a wind energy conversion system (WECS) needs to meet the stringent requirements in terms of reliability, efficiency, scalability and ease of maintenance, power quality, and dv/dt stress on the generator/transformer. Although the multilevel converters including the neutral point clamped (NPC) converter and the active NPC converter meet most of the requirements, they fall short in reliability …

Cerebrovascular Reactivity Alterations Due To Subconcussive Repetitive Head Trauma In Asymptomatic High School Football Players, Chetas Joshi

Open Access Theses

Chronic neurological damage as a result of chronic repetitive head trauma is a major concern for football athletes today. Repetitive concussions have been linked to many neurological disorders. Recently, it has been reported that repetitive subconcussive events can contribute to long-term neurodegeneration. For these reasons, it is important to understand the effect repetitive subconcussive head trauma has on brain health in young athletes. Past research has demonstrated that cerebrovascular reactivity (CVR), an important mediator of cerebrovascular regulation, is impaired following mild traumatic brain injury (mTBI). This impairment increases susceptibility to secondary injury following mTBI. In this study, Breath-Hold (BH) task …

Nanomechanical Characterization Of Thermo-Mechanical Properties Of Irradiated Zirconium With Consideration Of Temperature And Microstructure, Jonathan Thomas Marsh

Open Access Theses

Zirconium (Zr) and zirconium-alloys have been utilized in the nuclear industry for decades, most commonly in nuclear fuel cladding. The characteristics which make Zr ideal for these applications include: low density, high hardness, high ductility, and high corrosion resistance. Efforts have been made to further enhance these properties through the use of Zr-alloys, such as Zircaloy-2 and Zircaloy-4, which are made up 95-99% Zr by weight, with the remaining weight percentage being made of other metals (tin, niobium, nickel, iron, chromium). The performance of these materials directly influences the efficiency of the nuclear reactor and are thus of primary concern. …

Pavement Underdrain To Achieve Longer Life Pavement Structure, Tommy E. Nantung

Purdue Road School

Drainage as the key to pavement performance has been suggested since the early design of modern pavement structures. In fact, the three parameters for pavement performance are drainage, drainage and drainage. Drainage is so important to the performance of pavement that many state DOTs mandate a pavement underdrain system for routes with medium to high truck traffic. In the current evolution of pavement underdrain design, the speed of water removal from the soil foundation is the key issue. In a recent field investigation, some pavement sections with an underdrain system are not immune to pavement structural deterioration. It was determined …

Indygo Downtown Transit Center - Transforming Indianapolis, Ben Smith, Steve Robinson, Joe Fischer

Purdue Road School

The new IndyGo Downtown Transit Center will transform transit in downtown Indianapolis and offers lessons in transit planning, traffic planning, intermodal connectivity, public engagement, and pedestrian access. This presentation will give an overview of the facility and then focus on attributes of the facility and of the design process that might offer useful lessons to other transit projects, including those of a smaller scale

Pavement Rehabilitation Options In Indiana, David Holtz, Tommy E. Nantung, Lisa A. Egler-Kellems

Purdue Road School

Many pavement rehabilitation options are now available to maintain the function and structure of a pavement section, and pavement engineers can choose an option that is suitable for the existing pavement condition. Many agencies today use traditional pavement rehabilitation techniques such as patching, overlay, and mill and fill. Recent developments in materials and construction have made available new rehabilitation options that are not only cost effective but also increase the use of recycled materials. This presentation will feature hot-in-place recycling, cold-in-place recycling, and full-depth reclamation techniques used successfully with recently rehabilitated pavement sections in Indiana.

Railroad Quiet Zones, Glen T. Campbell, Mary Cripe

Purdue Road School

Speaker(s): Mary Cripe, P.E., City of Goshen Engineering Department

Glen Campbell, P.E., Patrick Engineering

Track: Multi-Modal Transportation

Submission ID #: 119

Presentation Duration: 50 Minutes

Presentation Title: Railroad Quiet Zones

Abstract: In 2005, the Federal Railroad Administration (FRA) provided communities with the opportunity to reduce locomotive horn noise without compromising public safety. The proposed Marion Branch Quiet Zone, located in Goshen, Indiana, will not only improve public safety, it will also enhance the quality of life and raise home values for adjacent residents.

This intricate process involves creative problem-solving and knowledge of the multiple parties involved. It will take a …

Social Media For Local Government Agencies, Sam Taylor

Purdue Road School

With more and more people communicating online, many local agencies are making the shift to include social media as part of their outreach efforts. This session will include a breakdown of the most common social me­dia networks used by local agencies, ideas for useful and engaging content, and a discussion of best practices for social media communications. Examples will be drawn from other local agency success stories, including local agencies within Indiana.

Simplified Pavement Design For Lpas: Introduction To Pavexpress, Dudley Bonte

Purdue Road School

Simplified Pavement Design for LPA's; An introduction to and use of PaveXpress, a simplified, free, web-based pavement design scoping tool for roadway and parking lot pavements. The system was developed by Pavia Systems in partnership with the National Asphalt Pavement Association. PaveXpress creates technical sound pavement structural designs for flexible and rigid pavements based on widely accepted industry standards from the Association of State Highway Officials (AASHTO). The simplified pavement design system is based on empirical equation from the 1993 AASHTO Guide for the Design of Pavement Structures. PaveXpress is intended for use by local agencies, engineers and consultants …

Gis Tools For Hydrology And Hydraulics, David D. Finley

Purdue Road School

GIS information sources used by the Office of Hydraulics to improve the accuracy and efficiency hydrologic computations will be presented. A variety of information sources will be discussed with an emphasis on DEM data obtained from Indiana's recent state-wide mapping initiative. Sources and limitations of the data will be discussed, and techniques for utilizing this data will be introduced.

2015 Directory Of Indiana State, County, City And Town Officials Responsible For Road And Street Work, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Directory

Contact information for local agency officials and employees responsible for Indiana’s local road infrastructure.

A Contribution Toward Better Understanding Of Overbanking Tendency In Fixed-Wing Aircraft, Nihad E. Daidzic

Journal of Aviation Technology and Engineering

The phenomenon of overbanking tendency for a rigid-body, fixed-wing aircraft is investigated. Overbanking tendency is defined as a spontaneous, unbalanced rolling moment that keeps increasing an airplane’s bank angle in steep turns and must be arrested by opposite aileron action. As stated by the Federal Aviation Administration, the overbanking tendency may lead to a loss of control, especially in instrument meteorological conditions. It was found in this study that the speed differential over wing halves in horizontal turns indeed creates a rolling moment that achieves maximum values for bank angles between 45 and 55 degrees. However, this induced rolling moment …

Investigating Problem-Based Learning Tutorship In Medical And Engineering Programs In Malaysia, Virginie F. C. Servant, Eleanor F. A. Dewar

Interdisciplinary Journal of Problem-Based Learning

Although Malaysia was the first country in Asia to adopt problem-based learning (PBL), the impact that this has had on its tutors remains largely unexplored. This paper details a qualitative study of the changing perceptions of teaching roles in two groups of problem-based learning tutors in two institutional contexts—one in medicine located in Kuala Lumpur and one in engineering located in Johor Bahru. Using Interpretive Phenomenological Analysis, the authors attempt to describe the way in which the two groups have experienced their changing professional world, and the mental processes through which they rationalize the transformation of Malaysia’s educational landscape. This …

Electronic Desalting For Controlling The Ionic Environment In Droplet-Based Biosensing Platforms, Vikhram Vilasur Swaminathan, Piyush Dak, Bobby Reddy Jr, Eric Salm, Carlos Duarte-Guevara, Yu Zhong, Andrew Fischer, Yi-Shao Liu, Rashid Bashir

Birck and NCN Publications

The ability to control the ionic environment in saline waters and aqueous electrolytes is useful for desalination as well as electronic biosensing. We demonstrate a method of electronic desalting at micro-scale through on-chip micro electrodes. We show that, while desalting is limited in bulk solutions with unlimited availability of salts, significant desalting of ≥1 mM solutions can be achieved in sub-nanoliter volume droplets with diameters of ∼250 μm. Within these droplets, by using platinum-black microelectrodes and electrochemical surface treatments, we can enhance the electrode surface area to achieve >99% and 41% salt removal in 1 mM and 10 mM salt …

Waste And Duplication In Nasa Programs: The Need To Enhance U.S. Space Program Efficiency, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

The U.S. Government faces acute budgetary deficits and national debt problems in the Obama Administration. These problems have been brought about by decades of unsustainable government spending affecting all agencies including the National Aeronautics and Space Administration. (NASA). An outgrowth of this fiscal profligacy is the presence of wasteful and duplicative programs within NASA that prevent this agency from achieving its space science and human spaceflight objectives. These problems occur due to mismanagement of these programs from NASA and the creation of these programs by the U.S. Congress and congressional committees. This occurs because congressional appropriators tend to be more …

Teaching Engineering, Second Edition, Phillip C. Wankat, Frank S. Oreovicz

Purdue University Press Books

The majority of professors have never had a formal course in education, and the most common method for learning how to teach is on-the-job training. This represents a challenge for disciplines with ever more complex subject matter, and a lost opportunity when new active learning approaches to education are yielding dramatic improvements in student learning and retention.

This book aims to cover all aspects of teaching engineering and other technical subjects. It presents both practical matters and educational theories in a format useful for both new and experienced teachers. It is organized to start with specific, practical teaching applications and …

The Integration Of Heat Resources In A Solar Thermal-Heat Pump Hydronic System, John Maxfield Degrove

Open Access Theses

According to the U.S. Department of Energy, roughly 41% of the energy consumed in the U.S. is used the power buildings. Within that number, almost half is used to heat or cool the building. Current technologies allow for consistent thermal management, but most utilize energy harvested from fossil fuels or convert electricity back into thermal energy. Background literature shows that the utilization of alternative heat resources such as heat pumps and solar thermal collectors can greatly reduce the energy used for heat delivery while producing adequate heating performance. A combined hydronic system using a bank of solar thermal collectors in …

Accelerating Mpi Collective Communications Through Hierarchical Algorithms With Flexible Inter-Node Communication And Imbalance Awareness, Benjamin Scott Parsons

Open Access Dissertations

This work presents and evaluates algorithms for MPI collective communication operations on high performance systems. Collective communication algorithms are extensively investigated, and a universal algorithm to improve the performance of MPI collective operations on hierarchical clusters is introduced. This algorithm exploits shared-memory buffers for efficient intra-node communication while still allowing the use of unmodified, hierarchy-unaware traditional collectives for inter-node communication. The universal algorithm shows impressive performance results with a variety of collectives, improving upon the MPICH algorithms as well as the Cray MPT algorithms. Speedups average 15x - 30x for most collectives with improved scalability up to 65536 cores.^ Further …