Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

154,670 Full-Text Articles 178,485 Authors 56,080,941 Downloads 307 Institutions

All Articles in Engineering

Faceted Search

154,670 full-text articles. Page 4560 of 4570.

Structural Health Monitoring With Piezoelectric Wafer Active Sensors—Predictive Modeling And Simulation, Victor Giurgiutiu 2010 University of South Carolina - Columbia

Structural Health Monitoring With Piezoelectric Wafer Active Sensors—Predictive Modeling And Simulation, Victor Giurgiutiu

Faculty Publications

This paper starts a review of the state of the art in structural health monitoring with piezoelectric wafer active sensors and follows with highlighting the limitations of the current approaches which are predominantly experimental. Subsequently, the paper examines the needs for developing a predictive modeling methodology that would allow to perform extensive parameter studies to determine the sensing method’s sensitivity to damage and insensitivity to confounding factors such as environmental changes, vibrations, and structural manufacturing variability. The thesis is made that such a predictive methodology should be multi-scale and multi-domain, thus encompassing the modeling of structure, sensors, electronics, and ...


Finite Element Analysis Of Cracks In Aging Aircraft Structures With Bonded Composite-Patch Repairs, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Shijia Zhao 2010 University of Nebraska-Lincoln

Finite Element Analysis Of Cracks In Aging Aircraft Structures With Bonded Composite-Patch Repairs, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Shijia Zhao

Mechanical & Materials Engineering Faculty Publications

Bonded composite-patch repair has been used to transfer load from cracked structures to the reinforcement such that subsequent crack propagation is reduced. In this study,the mechanical behavior of a single edge v-notch A17075-T6 plate repaired with 1-ply and 4-ply composite patches was investigated through the finite element method. Contour integral method was used to define and evaluate the stress intensity factors at the crack tip. The effect of the adhesive epoxy film, patch material, thickness and ply orientations on the evolution of the stress intensity factor (SIF) of the repaired structure was examined. The results indicated that the SIF ...


Directional Annealing-Induced Texture In Melt-Spun (Sm12Co88)99Nb1 Alloy, Tanjore V. Jayaraman, P. Rogge, Jeffrey E. Shield 2010 University of Nebraska-Lincoln

Directional Annealing-Induced Texture In Melt-Spun (Sm12Co88)99Nb1 Alloy, Tanjore V. Jayaraman, P. Rogge, Jeffrey E. Shield

Mechanical & Materials Engineering Faculty Publications

Developing texture in nanocrystalline permanent magnet alloys is of significant importance. Directional annealing is shown to produce texture in the permanent magnet alloy (Sm12Co88)99Nb1. Melt spinning produced isotropic grain structures of the hard magnetic metastable SmCo7 phase, with grain sizes of ∼300 nm. Conventional annealing of melt-spun (Sm12Co88)99Nb1 alloy produced Sm2Co17 phase with random crystallographic orientation. Directional annealing of melt-spun (Sm12Co88)99Nb1 alloy, with appropriate combinations of annealing temperature and translational velocity, produced Sm2Co17 phase with ...


Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli 2010 Thomas Jefferson University

Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: The octapeptide Angiotensin II is a key hormone that acts via its receptor AT1R in the brainstem to modulate the blood pressure control circuits and thus plays a central role in the cardiac and respiratory homeostasis. This modulation occurs via activation of a complex network of signaling proteins and transcription factors, leading to changes in levels of key genes and proteins. AT1R initiated activity in the nucleus tractus solitarius (NTS), which regulates blood pressure, has been the subject of extensive molecular analysis. But the adaptive network interactions in the NTS response to AT1R, plausibly related to the development of ...


Genome3d: A Viewer-Model Framework For Integrating And Visualizing Multi-Scale Epigenomic Information Within A Three-Dimensional Genome, Thomas M. Asbury, Matt Mitman, Jijun Tang, W. Jim Zheng 2010 University of South Carolina - Columbia

Genome3d: A Viewer-Model Framework For Integrating And Visualizing Multi-Scale Epigenomic Information Within A Three-Dimensional Genome, Thomas M. Asbury, Matt Mitman, Jijun Tang, W. Jim Zheng

Faculty Publications

Background
New technologies are enabling the measurement of many types of genomic and epigenomic information at scales ranging from the atomic to nuclear. Much of this new data is increasingly structural in nature, and is often difficult to coordinate with other data sets. There is a legitimate need for integrating and visualizing these disparate data sets to reveal structural relationships not apparent when looking at these data in isolation.

Results
We have applied object-oriented technology to develop a downloadable visualization tool, Genome3D, for integrating and displaying epigenomic data within a prescribed three-dimensional physical model of the human genome. In order ...


Using Jackknife To Assess The Quality Of Gene Order Phylogenies, Jian Shi, Yiwei Zhang, Haiwei Luo, Jijun Tang 2010 University of South Carolina - Columbia

Using Jackknife To Assess The Quality Of Gene Order Phylogenies, Jian Shi, Yiwei Zhang, Haiwei Luo, Jijun Tang

Faculty Publications

Background
In recent years, gene order data has attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. If gene orders are viewed as one character with a large number of states, traditional bootstrap procedures cannot be applied. Researchers began to use a jackknife resampling method to assess the quality of gene order phylogenies.

Results
In this paper, we design and conduct a set of experiments to validate the performance of this jackknife procedure and provide discussions on how to conduct it properly. Our results show that jackknife is very useful to ...


Excitation-Induced Germanium Quantum Dot Formation On Si (100)-(2×1), Ali Oguz Er, Hani E. Elsayed-Ali 2010 Old Dominion University

Excitation-Induced Germanium Quantum Dot Formation On Si (100)-(2×1), Ali Oguz Er, Hani E. Elsayed-Ali

Physics Faculty Publications

The effect of nanosecond pulsed laser excitation on the self-assembly of Ge quantum dots grown by pulsed laser deposition on Si (100)-(2×1) was studied. In situ reflection high-energy electron diffraction and ex situ atomic force microscopy were used to probe the quantum dot structure and morphology. At room temperature, applying the excitation laser decreased the surface roughness of the grown Ge film. With surface electronic excitation, crystalline Ge quantum dots were formed at 250 °C, a temperature too low for their formation without excitation. At a substrate temperature of 390 °C, electronic excitation during growth was found to ...


Development In The Gulf Of Maine: Avoiding Geohazards And Embracing Opportunities, Laura L. Brothers, Joseph T. Kelley, Melissa Landon Maynard, Daniel F. Belknap, Stephen M. Dickson 2010 University of Maine

Development In The Gulf Of Maine: Avoiding Geohazards And Embracing Opportunities, Laura L. Brothers, Joseph T. Kelley, Melissa Landon Maynard, Daniel F. Belknap, Stephen M. Dickson

Maine Policy Review

Mapping for marine-spatial planning is crucial if Maine is to safely develop its offshore resources, espe­cially wind and tidal energy. The authors focus on shallow natural gas (methane) deposits, an important and widespread geohazard in Maine’s seafloor. They describe the origin, occur­rence, and identification of natural gas in Maine’s seafloor; explain the hazards associated with these deposits and how to map them; and discuss what Maine can learn from European nations that have already developed their offshore wind resources. Because the U.S. gives states a central role in coastal management, Maine has the chance to ...


The Design And Manufacture Of A Light Emitting Diode Package For General Lighting, Michael S. Krist 2010 California Polytechnic State University, San Luis Obispo

The Design And Manufacture Of A Light Emitting Diode Package For General Lighting, Michael S. Krist

Master's Theses and Project Reports

Lighting technologies have evolved over the years to become higher quality, more efficient sources of light. LEDs are poised to become the market standard for general lighting because they are the most power efficient form of lighting and do not contain hazardous materials. Unfortunately, LEDs pose unique problems because advanced thermal management is required to remove the high heat fluxes generated by such relatively small devices. These problems have already been overcome with complex packaging and exotic materials, but high costs are preventing this technology from displacing current lighting technologies.

The purpose of this study is to develop a low-cost ...


Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Thaddaeus Bode, Yong-Rak Kim 2010 University of Nebraska-Lincoln

Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Thaddaeus Bode, Yong-Rak Kim

Nebraska Department of Transportation Research Reports

No abstract provided.


Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Yong-Rak Kim, Thaddaeus Bode 2010 University of Nebraska-Lincoln

Infrared Thermography-Driven Flaw Detection And Evaluation Of Hot Mix Asphalt Pavements, Yong K. Cho, Yong-Rak Kim, Thaddaeus Bode

Nebraska Department of Transportation Research Reports

This research was conducted to study more realistic explanations of how variables are created and dealt with during hot mix asphalt (HMA) paving construction. Several paving projects across the state of Nebraska have been visited where sensory devices were used to test how the selected variables contribute to temperature differentials including density, moisture content within the asphalt, material surface temperature, internal temperature, wind speed, haul time, and equipment type. Areas of high temperature differentials are identified using an infrared camera whose usefulness was initially confirmed with a penetrating thermometer. A non-nuclear density device was also used to record how the ...


Development Of A Family Of High Strength Low Carbon Microalloyed Ultra-Thin Cast Strip Products Produced By The Castrip® Process, Chris R. Killmore, Kristin R. Carpenter, Harold R. Kaul, James G. Williams, Daniel G. Edelman, Peter C. Campbell, Walter N. Blejde 2010 BlueScope Steel

Development Of A Family Of High Strength Low Carbon Microalloyed Ultra-Thin Cast Strip Products Produced By The Castrip® Process, Chris R. Killmore, Kristin R. Carpenter, Harold R. Kaul, James G. Williams, Daniel G. Edelman, Peter C. Campbell, Walter N. Blejde

Faculty of Engineering and Information Sciences - Papers: Part B

The manufacture of high strength strip products in strip thicknesses less than 1.5mm is very challenging for the conventional hot and cold rolled processing routes. A range of Nb and Nb/V microalloyed steels have been successfully strip cast by the CASTRIP process enabling the development of a range of high strength Ultra-Thin Cast Strip (UCS) products. It was found that the CASTRIP process fully exploits the strengthening potential of the low C-Mn-Nb-(V) alloy design system. Substantial strengthening by microstructural hardening was provided by Nb. Retention of Nb and V in solid solution in hot rolled coils enabled ...


Inverse Optimal Control As A Tool To Understand Human Yoyo Playing, Katja Mombaur, Manish Sreenivasa 2010 University of Heidelberg

Inverse Optimal Control As A Tool To Understand Human Yoyo Playing, Katja Mombaur, Manish Sreenivasa

Faculty of Engineering and Information Sciences - Papers: Part B

This paper presents an inverse optimal control approach to identify objective functions of human motion from motion capture measurements. We apply it to analyze human yoyo playing. Yoyo playing may seem easy to us to learn but it is a challenging problem from a mechanical point of view involving a hybrid dynamics model. We recorded vertical yoyo playing of humans measuring yoyo height and rotation angle as well as the corresponding hand motions. Results of inverse optimal control are presented showing a mixed criterion of cycle time and terms depending on yoyo and hand acceleration and velocity.


On Using Human Movement Invariants To Generate Target-Driven Anthropomorphic Locomotion, Manish Sreenivasa, Philippe Souères, Jean-Paul Laumond 2010 University of Wollongong

On Using Human Movement Invariants To Generate Target-Driven Anthropomorphic Locomotion, Manish Sreenivasa, Philippe Souères, Jean-Paul Laumond

Faculty of Engineering and Information Sciences - Papers: Part B

We present a method for generating anthropomorphic motion by studying `invariants' in human movements and applying them as kinematic tasks. We recorded whole-body motion of 14 participants during a walking and grasping task and performed a detailed analysis in order to synthesize the stereotypy in human motion as rules. We propose an algorithm that produces the key parameters of motion taking into account the knowledge from human movement, and the limitations of the anthropomorph. We generalize our results such that we can create motion parameters for objects which were not in the original protocol. The algorithmic output is applied in ...


Hrp-2 Plays The Yoyo: From Human To Humanoid Yoyo Playing Using Optimal Control, Katja Mombaur, Manish Sreenivasa 2010 University of Heidelberg

Hrp-2 Plays The Yoyo: From Human To Humanoid Yoyo Playing Using Optimal Control, Katja Mombaur, Manish Sreenivasa

Faculty of Engineering and Information Sciences - Papers: Part B

Yoyo playing may seem easy for a human, but it is a challenging problem for a humanoid robot. This paper presents an approach to generate yoyo motions for the humanoid robot, HRP-2, based on motion recorded from human yoyo playing, dynamical models and numerical optimal control techniques. We recorded vertical yoyo playing of 4 subjects measuring yoyo height and rotation angle as well as the corresponding hand motions. A detailed multi-phase yoyo model with impact collisions and control patterns of human yoyo playing were identified from these measurements. Based on this knowledge, reliable yoyo motions within the feasibility ranges of ...


Thermal Analog To Afm Force-Displacement Measurements For Nanoscale Interfacial Contact Resistance, Brian D. Iverson, John E. Blendell, Suresh V. Garimella 2010 Brigham Young University - Provo

Thermal Analog To Afm Force-Displacement Measurements For Nanoscale Interfacial Contact Resistance, Brian D. Iverson, John E. Blendell, Suresh V. Garimella

Faculty Publications

Thermal diffusion measurements on PMMA-coated Si substrates using heated AFM tips were performed to determine the contact resistance between an organic thin film and Si. The measurement methodology presented demonstrates how the thermal contrast signal obtained during a force-displacement ramp is used to quantify the resistance to heat transfer through an internal interface. The results also delineate the interrogation thickness beyond which thermal diffusion in the organic thin film is not affected appreciably by the underlying substrate.


An Experimental Study Of Surfactant Enhanced Waterflooding, Paulina Metili Mwangi 2010 Louisiana State University and Agricultural and Mechanical College

An Experimental Study Of Surfactant Enhanced Waterflooding, Paulina Metili Mwangi

LSU Master's Theses

Surfactants have a variety of applications in the petroleum industry due to their remarkable ability to lower the oil-water interfacial tension and alter wettability. However, surfactant adsorption on rock surfaces has severely crippled this means of improving oil recovery due to the high cost associated with the large quantities of surfactant needed. A previous experimental study by Ayirala (2002) reported the development of mixed wettability using a nonionic surfactant. At this mixed-wet state he was able to recover about 94% of the original oil in place. The underlying motivation of this study was to achieve such high recoveries without using ...


Estimated Impact Of Left Lane Truck Restriction On Louisiana Highway Pavement Using Mepdg, Mini Radhakrishnan 2010 Louisiana State University and Agricultural and Mechanical College

Estimated Impact Of Left Lane Truck Restriction On Louisiana Highway Pavement Using Mepdg, Mini Radhakrishnan

LSU Master's Theses

Truck lane restriction strategies (TLRS) are strategies used to manage truck traffic on highways by prohibiting trucks from using certain lanes in order to minimize interaction between trucks and other vehicles and currently it is under consideration for implementation in Louisiana’s multi-lane highways. One of the serious impacts of a truck lane restriction on highways is accelerated pavement damage on unrestricted lanes due to the increased truck traffic on them. The purpose of this study is to estimate the increased pavement damage on the right lane in terms of various distress caused by imposing left lane truck restriction on ...


Phase Investigation Of Zirconia Fibers And Their Applications On Solid Oxide Fuel Cells (Sofcs), Luping Li 2010 Louisiana State University and Agricultural and Mechanical College

Phase Investigation Of Zirconia Fibers And Their Applications On Solid Oxide Fuel Cells (Sofcs), Luping Li

LSU Master's Theses

Pure zirconia nanofibers were fabricated by electrospinning zirconia-polymer precursor and subsequent annealing. Fiber properties such as polymer decomposition, crystallization formation, phase transformation, surface morphologies, etc., were investigated by various techniques, including thermogravimetric analysis (TGA) and differential thermal analysis (DTA), high temperature differential scanning calorimeter (HTDSC), powder X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), etc. It was found the crystallization of as-spun fibers started at 450 °C and the initial crystallized zirconia phase was tetragonal (t), which began transforming to monoclinic (m) phase at 650 °C as evidenced by XRD; HTDSC showed at different thermal circles, the m-to-t transformation ...


The Weakening Of Branch Predictor Performance As An Inevitable Side Effect Of Exploiting Control Independence, Christopher Joseph Michael 2010 Louisiana State University and Agricultural and Mechanical College

The Weakening Of Branch Predictor Performance As An Inevitable Side Effect Of Exploiting Control Independence, Christopher Joseph Michael

LSU Doctoral Dissertations

Many algorithms are inherently sequential and hard to explicitly parallelize. Cores designed to aggressively handle these problems exhibit deeper pipelines and wider fetch widths to exploit instruction-level parallelism via out-of-order execution. As these parameters increase, so does the amount of instructions fetched along an incorrect path when a branch is mispredicted. Many of the instructions squashed after a branch are control independent, meaning they will be fetched regardless of whether the candidate branch is taken or not. There has been much research in retaining these control independent instructions on misprediction of the candidate branch. This research shows that there is ...


Digital Commons powered by bepress