Engineering Commons^™

Incorporation Of Globally Available Datasets Into The Roving Cosmic-Ray Neutron Probe Method For Estimating Field-Scale Soil Water Content, William A. Avery, Catherine Finkenbiner, Trenton E. Franz, Tiejun Wang, Anthony L. Nguy-Robertson, Andrew E. Suyker, Timothy J. Arkebauer, Francisco Munoz-Arriola

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The need for accurate, real-time, reliable, and multi-scale soil water content (SWC) monitoring is critical for a multitude of scientific disciplines trying to understand and predict the Earth’s terrestrial energy, water, and nutrient cycles. One promising technique to help meet this demand is fixed and roving cosmic-ray neutron probes (CRNPs). However, the relationship between observed low-energy neutrons and SWC is affected by local soil and vegetation calibration parameters. This effect may be accounted for by a calibration equation based on local soil type and the amount of vegetation. However, determining the calibration parameters for this equation is labor- and time-intensive, …

Micro/Nano-Structural Examination And Fission Product Identification In Neutron Irradiated Agr-1 Triso Fuel, I. J. Van Rooyen, T. M. Lillo, H. M. Wen, C. M. Hill, T. G. Holesinger, Y. Q. Wu, J. A. Aguiar

Materials Science and Engineering Faculty Publications and Presentations

Advanced electron microscopic and micro-analysis techniques were developed and applied to study irradiation effects and fission-product behavior in selected low-enriched uranium-oxide/uranium-carbide tristructural-isotropic (TRISO)-coated particles from fuel compacts in four capsules irradiated to burnups of 11.2 to 19.6% fissions per initial metal atom (FIMA) consisting of Baseline, Variant 1, and Variant 3 fuel types. Trend analysis shows precipitates were mostly random in their distribution along the perimeter of the inner pyrolytic carbon-silicon carbide (IPyC-SiC) interlayer with only weak association with kernel protrusion and buffer fractures. Pd is dominantly found in most precipitates in both intra and intergranular locations. Nano-sized Ag is …

Integrating Computational Modeling Modules Into Undergraduate Materials Science And Engineering Education, Lan (Samantha) Li

Materials Science and Engineering Faculty Publications and Presentations

To meet national workforce need, we integrated computational modeling training into undergraduate materials science and engineering (MSE) courses, including Thermodynamics, and Structure of Materials. We also flipped the courses, requiring students to self-study topics outside the class. In the class, the instructors focused on demonstrating real-world materials problems and guiding the students to solve the problems using different computational modeling techniques. Learning the computational modeling concepts within a short period of time was challenging to the students. Another challenge was that the students had various STEM backgrounds, such as MSE, mechanical engineering, and physics. In order to foster student learning, …

การปรับปรุงกระบวนการออกแบบชุดสายไฟในรถยนต์, ทิวารัตน์ สวัสดี

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยฉบับนี้ ทำการศึกษาเกี่ยวกับบริษัท ออกแบบสายไฟในรถยนต์ที่ให้ความสำคัญในเรื่องความพึงพอใจของลูกค้า ซึ่งเป็นหนึ่งในปัจจัยที่สำคัญที่สุดในการออกแบบผลิตภัณฑ์ ด้วยเหตุนี้บริษัท จึงใช้วิธีการทั้งหมดในการออกแบบกระบวนการออกแบบผลิตภัณฑ์ตามความต้องการที่หลากหลายของลูกค้า จึงทำให้มีการเปลี่ยนแปลงการออกแบบเป็นจำนวนมาก งานวิจัยนี้มีวัตถุประสงค์เพื่อปรับปรุงกระบวนการออกแบบชุดสายไฟในรถยนต์ที่มีผลต่อกำหนดการผลิตโดยใช้การวิเคราะห์ Fault Tree และ Failure Mode and Effect Analysis (FMEA) เป็นเครื่องมือหลัก FTA ใช้สำหรับการวิเคราะห์สาเหตุหลักและใช้ FMEA เพื่อจัดลำดับความสำคัญสูง (RPN) ซึ่งแสดงให้เห็นถึงความสำคัญของปัจจัยต่างๆในชุดสายไฟในรถยนต์ที่มีผลกระทบสูงต่อการออกแบบชุดสายไฟในรถยนต์ และหลังจากมีการปรับปรุงกระบวนการออกแบบและควบคุมปัจจัยที่ส่งผลเสียต่อกระบวนการออกแบบจะพบการขอเปลี่ยนแปลงการออกแบบที่ลดลงจาก 0.26 ครั้ง ต่อการออกแบบ 1 ครั้ง เป็น 0.06 ครั้ง ต่อการออกแบบ 1 ครั้ง แสดงถึงกระบวนการออกแบบที่ถูกปรับปรุงให้สามารถสร้างความพึงพอใจแก่ลูกค้าที่มีต่อผลิตภัณฑ์มากขึ้น

Identification And Reduction Of Retracker-Related Noise In Altimeter-Derived Sea Surface Height Measurements, Edward D. Zaron, Robert Decarvalho

Civil and Environmental Engineering Faculty Publications and Presentations

Data from the Jason-2 calibration/validation mission phase have been analyzed to identify the correlation between sea surface height (SSH) and significant wave height (SWH) errors.A cross-spectral analysis indicates that the SSH and SWH errors are nearly white and significantly correlated at scales from 12 to 100 km, consistent with the hypothesized error source, the waveform retracker. Because of the scale separation between the SWH signal and noise, it is possible to correct the SSH data by removing the SSH noise correlated with the SWH noise. Such a correction has been implemented using the empirical correlation found during the Jason-2 calibration …

The Effect Of Channel Deepening On Tides And Storm Surge: A Case Study Of Wilmington, Nc, R. Familkhalili, Stefan A. Talke

Civil and Environmental Engineering Faculty Publications and Presentations

In this study we investigate the hypothesis that increasing channel depth in estuaries can amplify both tides and storm surge by developing an idealized numerical model representing the 1888, 1975, and 2015 bathymetric conditions of the Cape Fear River Estuary, NC. Archival tide gauge data recovered from the U.S. National Archives indicates that mean tidal range in Wilmington has doubled to 1.55m since the 1880s, with a much smaller increase of 0.07mobserved near the ocean boundary. These tidal changes are reproduced by simulating channel depths of 7m (1888 condition) and 15.5m (modern condition). Similarly, model sensitivity studies using idealized, parametric …

Magnetoelastic Beam With Extended Polymer For Low Frequency Vibration Energy Harvesting, Alwathiqbellah Ibrahim, Shahrzad Towfighian, Mohammad I. Younis, Quang Su

Mechanical Engineering Faculty Scholarship

Ambient energy in the form of mechanical kinetic energy is mostly considered waste energy. The process of scavenging and storing such energy is known as energy harvesting. Energy harvesting from mechanical vibration is performed using resonant energy harvesters (EH) with two major goals: enhancing the power scavenged at low frequency sources of vibrations, and increasing the efficiency of scavenging energy by increasing the bandwidth near the resonant frequency. Toward such goals, we propose a piezoelectric EH of a composite cantilever beam with a tip magnet facing another magnet at a distance. The composite cantilever consists of a piezoelectric bimorph with …

Use Of Eportfolio As Integrated Learning Strategy In Computer Integrated Manufacturing Online Course, V. M. Jovanovic, Megan Mize, Rochelle Rodrigo, Alok K. Verma

Engineering Technology Faculty Publications

Integrated learning is a vital strategy for engaging undergraduate Engineering students in the higher levels of learning, as it encourages students to reflect on their learning processes and draw connections between course-work and "real-world" experiences. Specifically, ePortfolios encourage novice engineers to consider their learning processes over time, drawing connections between coursework and their intended profession, as well as cultivating an online identity that supports their efforts to pursue a career in Engineering. The use of ePortfolios is one method for fostering integrative learning, focusing on the application of digital communication and assessment and awareness of self-competence. By training students to …

An Asynchronous Course/Laboratory Development For Automation Controls, Cheng Y. Lin, Mileta Tomovic, Vukica M. Jovanovic

Engineering Technology Faculty Publications

The development of asynchronous courses is to help students who are restricted by work requirements, family responsibilities, geographical distance, disabilities, and combination of these factors. It also provides flexibilities to on-campus students. In this paper, the framework structure of an asynchronous course and laboratory development for an automation control is presented. The challenge in this development is to implement the hands-on laboratory experience to those distance learning students who may not be able to access the real equipment. Results of the implementation including opinion feedbacks and grade distributions show that students welcome the format of this development.

Teaching Robot Kinematics For Engineering Technology Students Using A Created Three-Dimensional Robot And Camera, Cheng Y. Lin, Yuzhong Shen

Engineering Technology Faculty Publications

Teaching robot kinematics is important to engineering technology students in the robot automation. The study can help students not only in the coordinate transformation principles from a joint to its following joint in a robot, but also in relating the coordinate systems between a robot and a machine vision system. While students can utilize math software to compute robot kinematic transformations, they have problems verifying their answers. In this paper, a three dimensional vertically articulated robot is created to help students visualize the location and orientation of the end effector. Students can check their robot kinematic answers based on the …

Secondary Flow Of Liquid-Liquid Two-Phase Fluids In A Pipe Bend, M. Ayala, P. Santos, G. Hamester, O. Ayala

Engineering Technology Faculty Publications

A simulated study of oil and water in 90 degree bend was carried on COMSOL 5.1 to characterize flow pattern and analyze the secondary flow. The Euler-Euler k-e Reynolds Averaged Navier-Stokes model was used to represent the fluid motion. Changes in the Reynolds number, curvature ratio and direction of gravity were made to evaluate the effects in the intensity of the secondary flow. In the end, it was possible to see that the bend direction does not affect the formation of secondary flow for Reynolds above 100,000. It appears that the fluid behavior on the pipe bend is strongly related …

Applications Of Digital Manufacturing In Manufacturing Process Support, Vukica Jovanovic, Mihael Debevec, Niko Herakovic, Alok Verma, Mileta Tomovic

Engineering Technology Faculty Publications

In this study, the authors developed three new approaches and models for improvements related to manufacturing processes. The main focus was on planning in a digital environment before the actual manufacturing process is carried out. The first approach is digital manufacturing, which gives affords the opportunity for performing an entire manufacturing process in a virtual environment. In this way, engineers virtually define, plan, create, monitor, and control all production processes. The planning phase can be done simultaneously, while other manufacturing processes are already in place. In this way, processes can continue with no interruption. Various product lifecycle management tools have …

The Reconfigurable Machinery Efficient Workspace Analysis Based On The Twist Angles, Ana M. Djuric, Vukica Jovanovic, Mirjana Filipovic, Ljubinko Kevac

Engineering Technology Faculty Publications

A novel methodology for the calculation, visualisation and analysis of the Reconfigurable Machinery Efficient Workspace (RMEW), based on the twist angles, is presented in this paper. The machinery's kinematic parameters are used for calculating the workspace, while the efficient workspace is associated with the machinery's path and includes the end-effector position and orientation. To analyse and visualise many different machinery efficient workspaces at the same time, the calculation is based on the previously developed and validated complex reconfigurable machinery's kinematic structure named n-DOF Global Kinematic Model (n-GKM). An industrial robot is used as an example to demonstrate …

Innovative System For Seismic Control Strategies, Seyed Ali Razavi

Dissertations and Theses

Among various alternative approaches, installing auxiliary damping devices such as tuned mass dampers (TMDs) is a very reliable solution to mitigate wind-induced vibration of tall buildings. However, regardless of the different distribution strategies, installing TMD systems means adding additional masses to tall buildings. A valuable space on top of tall buildings is sacrificed to contain a large bulky mass, which is not aesthetically pleasing. Furthermore, increasing the mass of tall buildings by installing extra mass systems is not time and cost effective process. In order to address the issues, this paper investigates the utilization of feasible alternative for the purpose …

A Two-Level Identity Model To Support Interoperability Of Identity Information In Electronic Health Record Systems., Xu Chen

Doctoral

The sharing and retrieval of health information for an electronic health record (EHR) across distributed systems involves a range of identified entities that are possible subjects of documentation (e.g., specimen, clinical analyser). Contemporary EHR specifications limit the types of entities that can be the subject of a record to health professionals and patients, thus limiting the use of two level models in healthcare information systems that contribute information to the EHR. The literature describes several information modelling approaches for EHRs, including so called “two level models”. These models differ in the amount of structure imposed on the information to be …

Fatigue Properties Of Magnetorheological Elastomers And The Design Of Interfacial Layers To Improve Fatigue Life., Yanfen Zhou

Doctoral

The primary aim of this PhD programme was to understand the fatigue behaviour of magnetorheological elastomers (MREs) and provide a reliable fatigue life predictor for this class of materials. To realise this aim required the study of the dynamic behaviour of MREs using the equi-biaxial bubble inflation test method. Isotropic and anisotropic MREs were fabricated from silicone rubber (SR) filled with soft carbonyl iron (CI) particles. The equi-biaxial fatigue behaviour of these samples was determined using a bubble inflation method. Wöhler (S-N) curves for both isotropic and anisotropic MREs were produced by subjecting the compounds to cycling over a range …

An Investigation To Evaluate The Feasibility Of An Intermodal Freight Transport System., Raja Maitra

Doctoral

The threat of greenhouse gases and the resulting climate change have been causing concern at international levels. This has led towards new sustainable policies towards reducing the anthropogenic effects on the environment and the population through promoting sustainable solutions for the freight industry. The research was prompted by the growing concerns that were no mode-choice tool to select as an alternative to road freight transport. There were growing concerns that a large percentage of transport related negativities, related various costs and pollution costs, losses arising from traffic accidents, delay costs from congestion and abatement costs due to climate impacts of …

Power Maximization For Pyroelectric, Piezoelectric, And Hybrid Energy Harvesting, Murtadha A. Shaheen

Theses and Dissertations

The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters.

A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance C_p and resistance R_p can be calculated at a frequency of 1 mHz to 1 Hz. …

Exploration Of Erasure-Coded Storage Systems For High Performance, Reliability, And Inter-Operability, Pradeep Subedi

Theses and Dissertations

With the unprecedented growth of data and the use of low commodity drives in local disk-based storage systems and remote cloud-based servers has increased the risk of data loss and an overall increase in the user perceived system latency. To guarantee high reliability, replication has been the most popular choice for decades, because of simplicity in data management. With the high volume of data being generated every day, the storage cost of replication is very high and is no longer a viable approach.

Erasure coding is another approach of adding redundancy in storage systems, which provides high reliability at a …

Filter Performance Under Simulated Real-World Conditions, Qiang Wang

Theses and Dissertations

Evaluating the performance of filter media for filtration applications is essential to assure design engineers and users that filter device will deliver promised performance for specific applications under the environmental stress. The study of particle loading characteristics of filter media in the laboratory setting is typically performed under the steady flow conditions, i.e., at the constant particle concentration and flow rate. In reality, filtration products are operated under the situations that the flow rate and mass concentration of particles are varied in time. The success of translating the laboratory data to estimate the performance of filter media in the fields …

Development And Characterization Of Lung Derived Extracellular Matrix Hydrogels, Robert A. Pouliot

Theses and Dissertations

Chronic obstructive pulmonary disease (COPD) including emphysema is a devastating condition, increasing in prevalence in the US and worldwide. There remains no cure for COPD, rather only symptomatic treatments. Due to unique challenges of the lung, translation of therapies for acute lung injury to target chronic lung diseases like COPD has not been successful. We have been investigating lung derived extracellular matrix (ECM) hydrogels as a novel approach for delivery of cellular therapies to the pulmonary system.

During the course of this work we have developed and characterized a lug derived ECM hydrogel that exhibits “injectability,” allowing cells or dugs …

An Injectable Stem Cell Delivery System For Treatment Of Musculoskeletal Defects, Shirae Leslie

Theses and Dissertations

The goal of this research was to develop a system of injectable hydrogels to deliver stem cells to musculoskeletal defects, thereby allowing cells to remain at the treatment site and secrete soluble factors that will facilitate tissue regeneration. First, production parameters for encapsulating cells in microbeads were determined. This involved investigating the effects of osmolytes on alginate microbead properties, and the effects of alginate microbead cell density, alginate microbead density, and effects of osteogenic media on microencapsulated cells. Although cells remained viable in the microbeads, alginate does not readily degrade in vivo for six months. Therefore, a method to incorporate …

Diagnostics And Degradation Investigations Of Li-Ion Battery Electrodes Using Single Nanowire Electrochemical Cells, Naveen Kumar Reddy Palapati, Naveen Kumar Reddy Palapati

Theses and Dissertations

Portable energy storage devices, which drive advanced technological devices, are improving the productivity and quality of our everyday lives. In order to meet the growing needs for energy storage in transportation applications, the current lithium-ion (Li-ion) battery technology requires new electrode materials with performance improvements in multiple aspects: (1) energy and power densities, (2) safety, and (3) performance lifetime. While a number of interesting nanomaterials have been synthesized in recent years with promising performance, accurate capabilities to probe the intrinsic performance of these high-performance materials within a battery environment are lacking. Most studies on electrode nanomaterials have so far used …

Surface Modification Techniques For Increased Corrosion Tolerance Of Zirconium Fuel Cladding, James Carr

Theses and Dissertations

Corrosion is a major issue in applications involving materials in normal and severe environments, especially when it involves corrosive fluids, high temperatures, and radiation. Left unaddressed, corrosion can lead to catastrophic failures, resulting in economic and environmental liabilities. In nuclear applications, where metals and alloys, such as steel and zirconium, are extensively em- ployed inside and outside of the nuclear reactor, corrosion accelerated by high temperatures, neu- tron radiation, and corrosive atmospheres, corrosion becomes even more concerning. The objec- tives of this research are to study and develop surface modification techniques to protect zirconium cladding by the incorporation of a …

The Molecular And Mechanical Mechanisms Of The Age-Associated Increase In The Severity Of Experimental Ventilator Induced Lung Injury, Joseph Ames Herbert

Theses and Dissertations

Abstract

Background

The majority of patients requiring mechanical ventilation are over the age of 65 and advanced age is known to increase the severity of ventilator-induced lung injury (VILI) and mortality. However, the mechanisms which predispose aging ventilator patients to increased mortality rates are not fully understood.

Pulmonary edema is a hallmark of VILI and the severity of edema increases with age. Ventilation with conservative fluid management decreases mortality rates in acute respiratory distress (ARDS) patients, but has not been investigated in VILI. We hypothesized that age-associated increases in pulmonary edema promote age-related increases in ventilator-associated mortality. Endoplasmic reticulum (ER) …

Optimizing Virtual Machine I/O Performance In Cloud Environments, Tao Lu

Theses and Dissertations

Maintaining closeness between data sources and data consumers is crucial for workload I/O performance. In cloud environments, this kind of closeness can be violated by system administrative events and storage architecture barriers. VM migration events are frequent in cloud environments. VM migration changes VM runtime inter-connection or cache contexts, significantly degrading VM I/O performance. Virtualization is the backbone of cloud platforms. I/O virtualization adds additional hops to workload data access path, prolonging I/O latencies. I/O virtualization overheads cap the throughput of high-speed storage devices and imposes high CPU utilizations and energy consumptions to cloud infrastructures. To maintain the closeness between …

Direct L2 Support Vector Machine, Ljiljana Zigic

Theses and Dissertations

This dissertation introduces a novel model for solving the L2 support vector machine dubbed Direct L2 Support Vector Machine (DL2 SVM). DL2 SVM represents a new classification model that transforms the SVM's underlying quadratic programming problem into a system of linear equations with nonnegativity constraints. The devised system of linear equations has a symmetric positive definite matrix and a solution vector has to be nonnegative.

Furthermore, this dissertation introduces a novel algorithm dubbed Non-Negative Iterative Single Data Algorithm (NN ISDA) which solves the underlying DL2 SVM's constrained system of equations. This solver shows significant speedup compared to several other state-of-the-art …

Electrophysiology Of Basal Ganglia (Bg) Circuitry And Dystonia As A Model Of Motor Control Dysfunction, Deepak Kumbhare

Theses and Dissertations

The basal ganglia (BG) is a complex set of heavily interconnected nuclei located in the central part of the brain that receives inputs from the several areas of the cortex and projects via the thalamus back to the prefrontal and motor cortical areas. Despite playing a significant part in multiple brain functions, the physiology of the BG and associated disorders like dystonia remain poorly understood. Dystonia is a devastating condition characterized by ineffective, twisting movements, prolonged co-contractions and contorted postures. Evidences suggest that it occurs due to abnormal discharge patterning in BG-thalamocortocal (BGTC) circuitry. The central purpose of this study …

Improving Understandability And Uncertainty Modeling Of Data Using Fuzzy Logic Systems, Dumidu S. Wijayasekara

Theses and Dissertations

The need for automation, optimality and efficiency has made modern day control and monitoring systems extremely complex and data abundant. However, the complexity of the systems and the abundance of raw data has reduced the understandability and interpretability of data which results in a reduced state awareness of the system. Furthermore, different levels of uncertainty introduced by sensors and actuators make interpreting and accurately manipulating systems difficult. Classical mathematical methods lack the capability to capture human knowledge and increase understandability while modeling such uncertainty.

Fuzzy Logic has been shown to alleviate both these problems by introducing logic based on vague …

In-Shoe Plantar Pressure System To Investigate Ground Reaction Force Using Android Platform, Ahmed A. Mostfa

Theses and Dissertations

Human footwear is not yet designed to optimally relieve pressure on the heel of the foot. Proper foot pressure assessment requires personal training and measurements by specialized machinery. This research aims to investigate and hypothesize about Preferred Transition Speed (PTS) and to classify the gait phase of explicit variances in walking patterns between different subjects. An in-shoe wearable pressure system using Android application was developed to investigate walking patterns and collect data on Activities of Daily Living (ADL). In-shoe circuitry used Flexi-Force A201 sensors placed at three major areas: heel contact, 1st metatarsal, and 5th metatarsal with a PIC16F688 microcontroller …