Engineering Commons^™

Uncertainty Quantification Models For Micro-Scale Squeeze-Film Damping, Xiaohui Guo, Jia Li, Dongbin Xiu, Alina Alexeenko

PRISM: NNSA Center for Prediction of Reliability, Integrity and Survivability of Microsystems

Two squeeze-film gas damping models are proposed to quantify uncertainties associated with the gap size and the ambient pressure. Modeling of gas damping has become a subject of increased interest in recent years due to its importance in micro-electro-mechanical systems (MEMS). In addition to the need for gas damping models for design of MEMS with movable micro-structures, knowledge of parameter dependence in gas damping contributes to the understanding of device-level reliability. In this work, two damping models quantifying the uncertainty in parameters are generated based on rarefied flow simulations. One is a generalized polynomial chaos (gPC) model, which is a …

Numerical Simulation Of A Liquid Jet Atomization And Break-Up Using Ansys-Cfx 12.0, Yash Akhil Bhatt

Master's Theses - Daytona Beach

Break-up and atomization characteristics of JetA liquid fuel were investigated numerically. The results have been compared to various experimental results to evaluate the accuracy of the numerical model. The CFD code ANSYS-CFX 12.0 was used to carry out the steady state analysis at different time scales. A comparison between the atomization characteristics of a pressure jet atomizer and an air-blast atomizer is shown. By employing a Lagrangian particle tracking method to track the path of the liquid particles, the liquid jet/spray phenomena was studied in light of low and high back pressure environments. The 'BLOB' primary atomization model and the …

Acuta Enews April 2010, Vol 39, No. 4

ACUTA Newsletters

ln This lssue

From the President.. ...,Harvey "Buck" Buchanan, Florida State Univ., ACUTA President

Board Report...........,.. George Denbow, Univ of Texas, ACUTA Secretary/Treasurer

Tech Talk Riding the Hype Cycle ...Kevin Tanzillo, Dux PR

Washington Update Newsletter

DC Update Dave Ostrom, Washington State Univ (retired)

Magnussen Named to Pandemic Planning Working Group

Congratulations to Sharon Stille and Mark Watters

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Development Of A Geopolymer-Based Cementitious Coating For The Rehabilitation Of Buried Concrete Infrastructure, Carlos Montes

Doctoral Dissertations

The current research project was devoted to the incorporation of geopolymers as a new material for Trenchless projects, taking advantage of their properties in a field in which they had not been used before, providing a substantial help to municipalities to meet their rehabilitation needs. Trenchless Technologies are a family of methods, materials and equipment capable of being used for the installation of new or replacement or rehabilitation of existing underground infrastructure with minimal disruption to surface traffic, business, and other activities.

The dissertation research work described herein is divided into six primary objectives: (1) the evaluation of geopolymer as …

Section Abstracts: Astronomy, Mathematics, And Physics & Materials Science

Virginia Journal of Science

Abstracts of papers of the Astronomy, Mathematics, and Physics (Including Materials Science) Section for the 88th Annual Meeting of the Virginia Academy of Science, May 20-21, 2010, James Madison University, Harrisonburg, VA.

Section Abstracts: Biomedical And General Engineering

Virginia Journal of Science

Abstracts of the Biomedical and General Engineering Section for the 88th Annual Meeting of the Virginia Academy of Science, May 20-21, 2010, James Madison University, Harrisonburg, VA.

Mechanical Properties Of Hydroxyapatite-Zirconia Compacts Sintered By Two Different Sintering Methods, Declan J. Curran, Thomas J. Fleming, Mark R. Towler, Stuart Hampshire

Chemical and Biochemical Engineering Faculty Research & Creative Works

Microwave sintering is traditionally employed to reduce the sintering temperature required to densify powder compacts. The effect of microwave heating on hydroxyapatite (HA)-zirconia (ZrO₂) green bodies has been investigated in order to understand how microwave energy may affect the physical and mechanical properties of the resultant densified composites. Laboratory synthesised nano-sized HA and a commercial nano-sized ZrO₂ powder have been ball milled to create mixtures containing 0-5 wt% ZrO₂ loadings. Compacts were microwave sintered at either 700, 1000 or 1200°C with a 1 h hold time. Comparative firings were also performed in a resistive element furnace …

Locked Plate Fixation Of Osteoporotic Humeral Shaft Fractures: Are Two Locking Screws Per Segment Enough?, David J. Hak, Peter Althausen, S J. Hazelwood

Biomedical Engineering

Objective: The purpose of this study was to compare the biomechanical behavior of using two versus three locking screws per bone segment in a cadaveric humerus fracture gap model.

Methods: Six matched pairs of elderly osteoporotic fresh–frozen human cadaveric humerii were used. An eight-hole locking compression plate was placed posteriorly on the humeral shaft and secured with either four or six bicortical locking screws. A 5-mm middiaphyseal gap osteotomy was created to simulate a comminuted fracture without bony contact. Specimens were tested in offset axial compression, four-point anteroposterior bending, four-point medial– lateral bending, and torsion. After the initial testing in …

Modeling The Long Term Effects Of Alendronate On Bone Mass Preservation Of The Femur With Articular Surface And Total Hip Replacements, Trevor J. Hryce

Master's Theses

Calculating femoral bone density changes after hip arthroplasty is of interest to researchers and clinicians for predicting the longevity of the prosthetic implant and the surrounding bone. Recently clinicians have been administering bisphosphonate drugs in an attempt to reduce the bone resorption due to stress shielding caused by these implants. Current strain-adaptive computational models with bisphosphonate treatment don’t predict the long term effects or look at treatment with hip resurfacing implants. The main goal of this study was to create and validate a computer model of the human femur incorporating a bone remodeling algorithm based on biological remodeling processes and …

Wave Energy Converter Performance Modeling And Cost Of Electricity Assessment, Dmitri Jarocki

Master's Theses

California is experiencing a rapid increase in interest for the potential of converting ocean waves into clean electricity. Numerous applications have been submitted for the permitting of such renewable energy projects; however the profitability, practicability, and survivability have yet to be proven. Wave energy conversion technology has steadily matured since its naissance in the 1970’s, several wave energy power installations currently exist, and numerous plans for commercial power plant are in the works on the shores of multiple continents. This study aims to assess the economic viability of two proposed commercial wave energy power plant projects on the Central California …

Assessing The V2-F Turbulence Models For Circulation Control Applications, Travis M. Storm

Master's Theses

In recent years, airports have experienced increasing airport congestion, partially due to the hub-and-spoke model on which airline operations are based. Current airline operations utilize large airports, focusing traffic to a small number of airports. One way to relieve such congestion is to transition to a more accessible and efficient point-to-point operation, which utilizes a large web of smaller airports. This expansion to regional airports propagates the need for next-generation low-noise aircraft with short take-off and landing capabilities. NASA has attacked this problem with a high-lift, low-noise concept dubbed the Cruise Efficient Short Take-Off and Landing (CESTOL) aircraft. The goal …

Correlating Nitrogen Accumulation With Temporal Fuel Cell Performance, Eric A. Müller, Florian Kolb, Lino Guzzella, Anna G. Stefanopoulou, Denise A. Mckay

Engineering: Faculty Publications

The permeability or crossover characteristics of a typical perfluorosulfonic acid base type membrane are used for the temporal and spatial estimations of nitrogen concentration along the anode channels of a polymer electrolyte membrane fuel cell stack. The predicted nitrogen accumulation is then used to estimate the impact of local fuel starvation on stack voltage through the notion of apparent current density. Despite the simplifying assumptions on the water accumulation and membrane hydration levels, the calibrated model predicts reasonably well the response of a 20-cell stack with a dead-ended anode. Specifically, the predicted voltage decay and the estimated gas composition at …

Multilevel Dc-Ac Converter Interface With Solar Panels, Yue Cao

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

This paper presents a single-phase 11-level (5 H-bridge) cascaded multilevel DC-AC converter that has implemented a Phase Locked Loop (PLL) and Maximum Power Point Tracking (MPPT) with 5 separate solar panel DC sources. This topology upgrades the conventional 3-level Pulse Width Modulation (PWM) controlled converter with advantages such as smoother output waveforms, more flexibility in voltage range, smaller filter size, and switching angle control. Simulation results of voltage synchronization using PLL and experimental setup and results implementing the entire converter interface are also presented.

Tracking Of Bone Mass And Density During Childhood And Adolescence, Heidi J. Kalkwarf, Vicente Gilsanz, Joan M. Lappe, Sharon Oberfield, John A. Shepherd, Thomas N. Hangartner, Xangke Huang, Margaret M. Frederick, Karen K. Winer, Babette S. Zemel

Biomedical, Industrial & Human Factors Engineering Faculty Publications

Context: Whether a child with low bone mineral density (BMD) at one point in time will continue to have low BMD, despite continued growth and maturation, is important clinically. The stability of a characteristic during growth is referred to as “tracking.”

Objective: We examined the degree of tracking in bone mineral content (BMC) and BMD during childhood and adolescence and investigated whether tracking varied according to age, sexual maturation, and changes in growth status.

Design: We conducted a longitudinal study with measurements at baseline and annually for 3 yr.

Setting: The Bone Mineral Density in Childhood Study was conducted at …

Input-Output Analysis Of Irish Construction Sector Greenhouse Gas Emissions, Adolf Acquaye, Aidan Duffy

Articles

Ireland is committed to limiting its greenhouse gas (GHG) emissions to 113% of 1990 levels over the period 2008-12 and to 84% of 2005 levels by 2020 under the Kyoto Agreement and the EU’s ’20 20’ by 2020 respectively. National policies have targeted many industry sectors but have failed to directly tackle GHG emissions associated with construction activity. This paper estimates energy and GHG emissions intensities of the Irish construction sector and subsectors and estimates its contribution to Irish national emissions. This information is used to identify and assess the impacts of policy measures which would result in a reduction …

Projected Costs Of A Grid-Connected Domestic Pv System Under Different Scenarios In Ireland, Using Measured Data From A Trial Installation, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon

Articles

This paper presents results of a study of projected costs for a grid-connected PV system for domestic application in Ireland. The study is based on results from a 1.72kWpPV system installed on a flat rooftop in Dublin, Ireland. During its first year of operation a total of 885.1kWh/kWp of electricity was generated with a performance ratio of 81.5%. The scenarios employed in this study consider: a range of capital costs; cost dynamics based on a PV module learning rate of 2+/-75%; projections for global annual installed PV capacity under an advanced and moderate market growth conditions; domestic electricity cost growth …

Opening The Door, Robert Gubbels, Tate Mackay, Chance Bohr, Jake Broyles

Service-Learning Program

Josiah mainly has problems opening the doors at the Morrison Center, its doors have a specific handle he cannot get on his own. The handle is vertical and is about nine inches in length and four inches wide; it has ridges on the front for grip and a lip on the back. He wants a device that attaches to the handle that is connected to a rope where his service dog then pulls the door open. The item will have to be easily applicable and removable for simple use since Josiah has limited movement in his hands.

Recent Advances In High Density Area Array Interconnect Bonding For 3d Integration, J. M. Lannon, J., C. Gregory, M. Lueck, A. Huffman, D. Temple, Amy J. Moll, William B. Knowlton

Materials Science and Engineering Faculty Publications and Presentations

The demand for more complex and multifunctional micro systems with enhanced performance characteristics for military applications is driving the electronics industry toward the use of best-of-breed materials and device technologies. Threedimensional (3-D) integration provides a way to build complex microsystems through bonding and interconnection of individually optimized device layers without compromising system performance and fabrication yield. Bonding of device layers can be achieved through polymer bonding or metal-metal interconnect bonding with a number of metalmetal systems. RTI has been investigating and characterizing Cu-Cu and CulSn-Cu processes for high density area array imaging applications, demonstrating high yield bonding between sub-I5 11m …

Cs 206: Computer Software Productivity Tools, John P. Herzog

Computer Science & Engineering Syllabi

Focus on learning MS Office software applications including advanced topics in spreadsheets, database and presentation graphics, using a case study approach where critical thinking and problem solving skills are required. Computer concepts are integrated throughout the course to provide an understanding of advanced computing, the latest technological advances and how they are used in industry. Ethics and issues encountered in business are discussed to challenge students on societal impact of technology.

Cs 790: Optimizing Compliers For Modern Architectures, Meilin Liu

Computer Science & Engineering Syllabi

This course studies compiler optimization for modern architectures. Between parsing the input program and generating the target machine code, optimizing compilers perform a wide range of program transformations on a program to improve its performance. In this course we focus on data dependence analysis, program transformations and loop transformations, loop scheduling, and a combination of these optimizing techniques.

Upper Extremity Kinetics During Lofstrand Crutch-Assisted Gait In Children, Neha Bhagchandani

Master's Theses (2009 -)

Complete biomechanical analysis helps evaluate the motion during various gait patterns for the upper and lower extremities. Extensive studies have been performed to evaluate unassisted gait patterns, but very little has been accomplished for studying assisted motion. Children with pathologies such as osteogenesis imperfecta, spinal cord injury, and cerebral palsy use assistive devices such as anterior and posterior walkers, canes, Lofstrand and axillary crutches for ambulation purposes.

Statistics show that there are currently about 566,000 crutch users in the United States. The long-term crutch users in this population can suffer various upper limb pathologies associated with extensive upper extremity (UE) …

Characterization Of An Implicitly Resistively-Loaded Monopole Antenna In Lossy Liquid Media, Colleen J. Fox, Paul M. Meaney, Fridon Shubitidze, Lincoln Potwin, Keith D. Paulsen

Dartmouth Scholarship

Abstract

Microwave tomographic imaging of the breast for cancer detection is a topic of considerable interest because of the potential to exploit the apparent high-dielectric property contrast between normal and malignant tissue. An important component in the realization of an imaging system is the antenna array to be used for signal transmission/detection. The monopole antenna has proven to be useful in our implementation because it can be easily and accurately modeled and can be positioned in close proximity to the imaging target with high-element density when configured in an imaging array. Its frequency response is broadened considerably when radiating in …

Non Bayesian Conditioning And Deconditioning, Jean Dezert, Florentin Smarandache

Branch Mathematics and Statistics Faculty and Staff Publications

In this paper, we present a Non-Bayesian conditioning rule for belief revision. This rule is truly Non-Bayesian in the sense that it doesn’t satisfy the common adopted principle that when a prior belief is Bayesian, after conditioning by X, Bel(X|X) must be equal to one. Our new conditioning rule for belief revision is based on the proportional conflict redistribution rule of combination developed in DSmT (Dezert-Smarandache Theory) which abandons Bayes’ conditioning principle. Such Non-Bayesian conditioning allows to take into account judiciously the level of conflict between the prior belief available and the conditional evidence. We also introduce the deconditioning problem …

Use Of Dynamic Cone Penetration And Clegg Hammer Tests For Quality Control Of Roadway Compaction And Construction, Hobi Kim, Monica Prezzi, Rodrigo Salgado

JTRP Technical Reports

Soil compaction quality control presently relies on the determination of the in-place compacted dry unit weight, which is then compared with the maximum dry unit weight obtained from a laboratory compaction test. INDOT requires that the in-place dry unit weight for compacted soil be over 95% of the laboratory maximum dry unit weight. In order to determine the in-place dry unit weight, INDOT engineers generally use nuclear gauges, which are hazardous and also costly because of the required safety precautions. Thus, several alternative tests such as the Dynamic Cone Penetration Test (DCPT) and the Clegg Hammer Test (CHT) were introduced …

Geotechnical Design Based On Cpt And Pmt, Daehyeon Kim, Younjin Shin, Nayyar Siddiki

JTRP Technical Reports

This research presents the correlation of undrained shear strength based on the cone resistance from the cone penetration test (CPT) for clayey soils in Indiana. It utilized the field cone penetration test program including the CPT, the index test, the one dimensional test and the triaxial test. The cone factor, which is essential to reliable estimation of undrained shear strength from cone resistance, has been evaluated considering the plasticity index of soils. The cone factor is influenced by the penetration rate during the CPT and test methods that are used for obtaining the undrained shear strength. The rate effect of …

Cs 499/699: Logic For Computer Scientists, Pascal Hitzler

Computer Science & Engineering Syllabi

Logic is often called the Calculus of Computer Science. Indeed, logic permeates most areas of Computer Science in one way or the other, sometimes more prominently, and sometimes as motivational or formal underpinning. Examples are database schema, program verification, semantics of programming languages, computer security, artificial intelligence, cognitive robotics, Web information systems, computer hardware circuitry, or modeling in software engineering.

Cs 740: Algorithms, Complexity And The Theory Of Computability, Pascal Hitzler

Computer Science & Engineering Syllabi

What does it mean to say that some computational problem is intrinsically more difficult than some other problem? How can I claim that I have found a good algorithmic solution? The study of these questions gives rise to an area of Theoretical Computer Science called Complexity Theory, which is based on a systematic and thorough formal study of the complexity of problems with respect to their algorithmic solvability, using Turing machines as main conceptual tool. In this class, we will understand how problem and algorithmic complexity is measured, and discuss some of the main complexity classes arising from this study. …

Cs 400/600: Data Structures And Software Design, Guozhu Dong

Computer Science & Engineering Syllabi

No abstract provided.

Cs 142: Computer Programming - Ii, Michael Ondrasek

Computer Science & Engineering Syllabi

The concepts introduced in CS 141 are developed in greater detail and depth with the Java programming language. Topics include object oriented programming, graphics, development, of user interfaces and handling runtime errors with an emphasis on program verification and testing. Students must register for both lecture and one laboratory section. 4 credit hours. Prerequisite: CS 141 (Computer Programming I) and MTH 127 (College Algebra) or equivalent.

Cs 141: Computer Programming - I, Michael Ondrasek

Computer Science & Engineering Syllabi

This course provides a general introduction to the fundamentals of computer programming. Examples from and applications to a broad range of problems are given. No prior knowledge of programming is assumed. The concepts covered will be applied to the Java programming language. Students must register for both lecture and one laboratory section. 4 credit hours. Prerequisite: MTH 127 (College Algebra) or equivalent.