Digital Commons Network^™

Damage Detection Analysis Using Lamb Waves In Restricted Geometry For Aerospace Applications, Roman T. Underwood

Theses and Dissertations

Today many USAF aircraft are approaching the end of their projected service life. However, those aircraft, such as the F-15 Eagle, are still being operated to accomplish the mission of the USAF. As the F-15 ages the required maintenance increases, as does the risk of structural failure. A goal of structural health monitoring (SHM) programs is to increase aircraft safety by monitoring areas known to have structural failures. Currently, time intensive manual inspections are used to monitor failure “hotspots” decreasing the readiness of the F-15 fleet. The lead ziconate titanate (PZT) is a commonly used piezoelectric transducer that has shown …

Microfluidic Power Generation, Aaron J. Sprecher

Theses and Dissertations

This thesis includes the detailed mathematical calculations used to determine the feasibility of harnessing electrical energy from the blood flow through human capillaries. The designs are inspired by human physiology and well established electromagnetic energy harvesting techniques and the fabrication methods have been proposed for the various components of the device. The fabrication and the design of these components have also been extensively analyzed using calculations based on the governing principles of microfluidics, kinetics, and electromagnetics. The analysis has confirmed that this design can produce sufficient energy to power a MEMS device using non-standard materials and fabrication methods. The designs …

Experimental Evaluation Of The Nightcool Nocturnal Radiation Cooling Concept: Annual Performance Assessment In Scale Test Buildings, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

An experimental evaluation has been conducted on a night sky cooling system designed to substantially reduce space cooling needs in homes in North American climates. The system uses a sealed attic covered by a highly conductive metal roof (a roof integrated radiator) which is selectively linked by air flow to the main zone with the attic zone to provide cooling--largely during nighttime hours. Available house mass is used to store sensible cooling. Additional dehumidification is done during the evening hours as warranted by interior conditions.

An initial report describes a detailed simulation model of the relevant night cooling phenomenon, examining …

Climate Change Scenarios For The California Region, Daniel R. Cayan, Edwin P. Maurer, Michael D. Dettinger, Mary Tyree, Katharine Hayhoe

Civil, Environmental and Sustainable Engineering

To investigate possible future climate changes in California, a set of climate change model simulations was selected and evaluated. From the IPCC Fourth Assessment, simulations of twenty-first century climates under a B1 (low emissions) and an A2 (a medium-high emissions) emissions scenarios were evaluated, along with occasional comparisons to the A1fi (high emissions) scenario. The climate models whose simulations were the focus of the present study were from the Parallel Climate Model (PCM1) from NCAR and DOE, and the NOAA Geophysical Fluid Dynamics Laboratory CM2.1 model (GFDL). These emission scenarios and attendant climate simulations are not “predictions,” but rather are …

Now Hear This! What All Environmental Engineers Should Know About Noise Control, Harold M. Cota, Mark Bastasch, Roger Wayson, Tracy Thatcher

Civil and Environmental Engineering

Noise is an is an that affects almost everyone. And even though environmental engineers are often called on to deal with noise-related problems, most of them receive little or no academic training in noise control. This primer suggests why all environmental engineers should know something about noise control, what they need to know, and where they can find the necessary information.

How To Measure A Degree Of Mismatch Between Probability Models, P-Boxes, Etc.: A Decision-Theory-Motivated Utility-Based Approach, Luc Longpre, Scott Ferson, W. Troy Tucker

Departmental Technical Reports (CS)

Different models can be used to describe real-life phenomena: deterministic, probabilistic, fuzzy, models in which we have interval-valued or fuzzy-valued probabilities, etc. Models are usually not absolutely accurate. It is therefore important to know how accurate is a given model. In other words, it is important to be able to measure a mismatch between the model and the empirical data. In this paper, we describe an approach of measuring this mismatch which is based on the notion of utility, the central notion of utility theory.

We also show that a similar approach can be used to measure the loss of …

Non-Invasive Raman Tomographic Imaging Of Canine Bone Tissue, Matthew V. Schulmerich, Jacqueline H. Cole, Kathryn A. Dooley, Michael D. Morris, Jaclynn M. Kreider, Steven A. Goldstein, Subhadra Srinivasan, Brian W. Pogue

Dartmouth Scholarship

Raman spectroscopic diffuse tomographic imaging has been demonstrated for the first time. It provides a noninvasive, label-free modality to image the chemical composition of human and animal tissue and other turbid media. This technique has been applied to image the composition of bone tissue within an intact section of a canine limb. Spatially distributed 785-nm laser excitation was employed to prevent thermal damage to the tissue. Diffuse emission tomography reconstruction was used, and the location that was recovered has been confirmed by micro-computed tomography (micro-CT) images.

With recent advances, diffuse tomography shows promise for in vivo clinical imaging.^{1, …}

Spatial Variations In Nutrient And Microbial Transport From Feedlot Surfaces, John E. Gilley, Elaine D. Berry, Roger A. Eigenberg, David B. Marx, Bryan L. Woodbury

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nutrient and microbial transport by runoff may vary at different locations within a beef cattle feedlot. If the areas making the largest contributions to nutrient and microbial transport can be identified, it may be possible to institute site‐specific management practices to reduce runoff nutrient and microbial transport. The objectives of this study were to: (1) measure selected feedlot soil properties and nutrient and microbial transport in runoff from various feedlot locations, (2) compare the effects of unconsolidated surface materials (USM) (loose manure pack) and consolidated subsurface materials (CSM) (compacted manure and underlying layers) on nutrient and microbial transport, and (3) …

Simulation Modeling And Analysis Of F-16 Pilot Training Squadron, Adem Okal

Theses and Dissertations

The need for fighter pilots in the Turkish Air Force is expected to increase with the planned acquisition of Joint Strike Fighters, ongoing new F-16 purchases, and other upgrades to the Turkish Air Force fighter inventory. This increased demand will affect the current fighter training squadron curriculum and scheduling. This study focuses on issues related to 143^rd Oncel squadron F-16 Pilot Training with this projected increase in number of student pilots (SP). Completing the training periods on time is an important issue along with maintaining effective training performance. In our study the Total Time of the training period serves …

An Effect Of Relative Motion On Trajectory Discrimination, Scott A. Beardsley, Lucia M. Vaina

Biomedical Engineering Faculty Research and Publications

Psychophysical studies point to the existence of specialized mechanisms sensitive to the relative motion between an object and its background. Such mechanisms would seem ideal for the motion-based segmentation of objects; however, their properties and role in processing the visual scene remain unclear. Here we examine the contribution of relative motion mechanisms to the processing of object trajectory. In a series of four psychophysical experiments we examine systematically the effects of relative direction and speed differences on the perceived trajectory of an object against a moving background. We show that background motion systematically influences the discrimination of object direction. …

Network Visualization Design Using Prefuse Visualization Framework, John Mark Belue

Theses and Dissertations

Visualization of network simulation events or network visualization is an effective and low cost method to evaluate the health and status of a network and analyze network designs, protocols, and network algorithms. This research designed and developed a network event visualization framework using an open source general visualization toolkit. This research achieved three major milestones during the development of this framework: A robust network simulator trace file parser, multiple network visualization layouts {including user-defined layouts, and precise visualization timing controls and integrated display of network statistics. The parser architecture is extensible to allow customization of simulator trace formats that are …

Computational Models Of Tandem Src Homology 2 Domain Interactions And Application To Phosphoinositide 3-Kinase, Dipak Barua, James R. Faeder, Jason M. Haugh

Chemical and Biochemical Engineering Faculty Research & Creative Works

Intracellular signal transduction proteins typically utilize multiple interaction domains for proper targeting, and thus a broad diversity of distinct signaling complexes may be assembled. Considering the coordination of only two such domains, as in tandem Src homology 2 (SH2) domain constructs, gives rise to a kinetic scheme that is not adequately described by simple models used routinely to interpret in vitro binding measurements. To analyze the interactions between tandem SH2 domains and bisphosphorylated peptides, we formulated detailed kinetic models and applied them to the phosphoinositide 3-kinase p85 regulatory subunit/platelet-derived growth factor β-receptor system. Data for this system from different in …

Effects Of Ionic Strength, Temperature, And Ph On Degradation Of Selected Antibiotics, Keith A. Loftin, Craig D. Adams, Michael T. Meyer, Rao Surampalli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Aqueous degradation rates, which include hydrolysis and epimerization, for chlorretracycline (CTC), oxytetracycline (OTC), tetracycline (TET), lincomycin (LNC), sulfachlorpyridazine (SCP), sulfadimethoxine (SDM), sulfathiazole (STZ), trimethoprim (TRM), and tylosin a (TYL) were studied as a function of ionic strength (0.0015, 0.050, or 0.084 mg/L as Na2HPO4), temperature (7, 22, and 35°C), and pH (2, 5, 7, 9, and 11). Multiple linear regression revealed that ionic strength did not significantly affect (α = 0.05) degradation rates for all compounds, but temperature and pH affected rates for CTC, OTC, and TET significand (α = 0.05). Degradation also was observed for TYL at pH 2 …

Forecasting Instability Indicators In The Horn Of Africa Region, Bryan R. Tannehill

Theses and Dissertations

The forecasting of state failure and the associated indicators has been a topic of great interest to a number of different agencies. USAID, CENTCOM, the World Bank, the Center for Army Analyses, and others have all examined the subject based on their own specific objectives. Whether the goal is denying terrorists space in which to operate, deciding how to pre-position materials in anticipation of unrest, stabilizing foreign markets and trade, or preventing or mitigating humanitarian disasters, man made or otherwise, this topic has been of interest for over a decade. The Horn of Africa has been one of the least …

A Decision Tool To Evaluate Budgeting Methodologies For Estimating Facility Recapitalization Requirements, Krista M. Hickman

Theses and Dissertations

The purpose of this research was to develop a decision tool to assist in the evaluation of facility recapitalization budget estimation models to determine which model was best suited for a particular organization. Specifically, this thesis sought to answer an overarching research question addressing the importance of recapitalization and the best method to estimate the facility recapitalization budget using the Department of Defense (DoD) as the subject of the research. A comprehensive literature review revealed ten existing recapitalization model alternatives to consider for implementation. The methodology used to develop a decision tool was based on the Value Focused Thinking (VFT) …

The Impact Of Operations Tempo (Optempo) On Intentions To Depart The Military. Does The Increase Of Optempo Cause Action, Nathan P. Olsen

Theses and Dissertations

Recent information in the field of Operations Tempo (OPTEMPO) has resulted in conflicting information on its effect on turnover intentions. This study evaluated the August 2004 Status of Forces Survey to determine if the sample demonstrated OPTEMPO had a curvilinear effect on turnover intentions when accounting for the moderators job satisfaction and organizational commitment while controlling for rank and gender. Linear regressions were used to determine if the relationship between OPTEMPO and turnover intentions were significant. When accounting for job satisfaction and organizational commitment the relationship between OPTEMPO and turnover intentions is not significant, this indicated that OPTEMPO and turnover …

Linking Embeddedness And Macroinvertebrate In Two Southwest Ohio Streams, Jonathan P. Kochersberger

Theses and Dissertations

Environmental managers utilize a variety of tools when assessing lotic systems for stressors attributed to anthropogenic sources. Stream deposited sediment has been recognized as one of the major stressors affecting streams in the U.S. The detrimental effect on aquatic biota of sediment depositing within the interstitial spaces of stream substrate (embeddedness) has been established, yet lacking is an effective in situ method of quantifying embeddedness over short time periods. The goal of this research was to develop a short-term embeddedness (EMB) quantification method that can be linked to benthic macroinvertebrate health. Such a method would be a valuable tool when …

Semantic Components: A Model For Enhancing Retrieval Of Domain- Specific Information, Susan Loucette Price

Dissertations and Theses

Despite the success of general Internet search engines, information retrieval remains an incompletely solved problem. Our research focuses on supporting domain experts when they search domain-specific libraries to satisfy targeted information needs. The semantic components model introduces a schema specific to a particular document collection. A semantic component schema consists of a two-level hierarchy, document classes and semantic components. A document class represents a document grouping, such as topic type or document purpose. A semantic component is a characteristic type of information that occurs in a particular document class and represents an important aspect of the document’s main topic. …

Electrically Steerable Diffraction Gratings For Hyperspectral Imaging: A Microelectromechanical System Design And Fabrication, Saban Atinc Delican

Theses and Dissertations

The current research is focused on the design and fabrication of an electrically programmable diffraction grating using standard micro electro mechanical systems (MEMS) technology. The goal is to design a beam steering element required to build very small hyperspectral imaging (HSI) sensors. The diffraction grating will be used to perform beam-dispersion - a critical step in the imaging process. The proposed transmissive diffraction grating based approach will minimize the overall size and the number of components in the physical design of the hyperspectral imagers, thereby enabling us to exploit the traditional advantages of MEMS such as increased reliability, smaller size, …

A Weighted Least-Squares Method For Inverse Dynamic Analysis, Antonie J. Van Den Bogert, Anne Su

Mechanical Engineering Faculty Publications

Internal forces in the human body can be estimated from measured movements and external forces using inverse dynamic analysis. Here we present a general method of analysis which makes optimal use of all available data, and allows the use of inverse dynamic analysis in cases where external force data is incomplete. The method was evaluated for the analysis of running on a partially instrumented treadmill. It was found that results correlate well with those of a conventional analysis where all external forces are known.

Acuta Enews February 2008, Vol. 37, No. 2

ACUTA Newsletters

ln This lssue

From the President........ Walt Magnussen, Texas A&M Univ., ACUTA President

Board Report ................... Riny Ledgerwood, San Diego Stale Univ, , ACUTA, Sec./Treasurer

Check lt Out: RFls/RFPs, Job Postings, Press Releases

Tech Talk: What Kind of Experience Does Your Website Provide?.............Kevin Tanzillo, Dux PR

DC Update ............Jeanne Jansenius, Sewonee, The University of the South

Grant Money for Minority College Wireless Networks

Ethernet Alliance White Paper Challenge

lnfo Links ............. Randy Hayes, Univ. of Northern lowa

Deadline for lnstitutional Excellence Awards ls February 15

Welcome New Members

Effects Of Climate Change On Energy Production And Use In The United States, Thomas Wilbanks, Vatsal Bhatt, Daniel Bilello, Stanley Bull, James Ekmann, William Horak, Y. Joe Huang, Mark D. Levine, Michael J. Sale, David Schmalzer, Michael J. Scott

United States Department of Energy: Publications

Climate change is expected to have noticeable effects in the United States: a rise in average temperatures in most regions, changes in precipitation amounts and seasonal patterns in many regions, changes in the intensity and pattern of extreme weather events, and sea level rise. Some of these effects have clear implications for energy production and use. For instance, average warming can be expected to increase energy requirements for cooling and reduce energy requirements for warming. Changes in precipitation could affect prospects for hydropower, positively or negatively. Increases in storm intensity could threaten further disruptions of the sorts experienced in 2005 …

Effects Of Climate Change On Aquatic Invasive Species And Implications For Management And Research, Roxanne Thomas, Austin Kane, Environmental Law Institute, Britta G. Bierwagen

United States Environmental Protection Agency: Publications

Global change stressors, including climate change and variability and changes in land use, are major drivers of ecosystem alterations. Invasive species, which are non-native species that cause environmental or economic damages or human-health impacts, also contribute to ecosystem changes. The interactions between stressors and invasive species, although not well understood, may exacerbate the impacts of climate change on ecosystems, and likewise, climate change may enable further invasions. This report reviews available literature on climate-change effects on aquatic invasive species (AIS) and examines state-level AIS management activities. Data on management activities came from publicly available information, was analyzed with respect to …

Bifidobacteria In Feces And Environmental Waters, Regina Lamendella, Jorge W. Santo Domingo, Catherine Kelty, Daniel B. Oerther

United States Environmental Protection Agency: Publications

Bifidobacteria have been recommended as potential indicators of human fecal pollution in surface waters even though very little is known about their presence in nonhuman fecal sources. The objective of this research was to shed light on the occurrence and molecular diversity of this fecal indicator group in different animals and environmental waters. Genus- and species-specific 16S rRNA gene PCR assays were used to study the presence of bifidobacteria among 269 fecal DNA extracts from 32 different animals. Twelve samples from three wastewater treatment plants and 34 water samples from two fecally impacted watersheds were also tested. The species-specific assays …

Mineral Trioxide Aggregate Material Use In Endodontic Treatment: A Review Of The Literature, Howard W. Roberts, Jeffrey M. Toth, David W. Berzins, David G. Charlton

Biomedical Engineering Faculty Research and Publications

Objective

The purpose of this paper was to review the composition, properties, biocompatibility, and the clinical results involving the use of mineral trioxide aggregate (MTA) materials in endodontic treatment.

Methods

Electronic search of scientific papers from January 1990 to August 2006 was accomplished using PubMed and Scopus search engines (search terms: MTA, GMTA, WMTA, mineral AND trioxide AND aggregate).

Results

Selected exclusion criteria resulted in 156 citations from the scientific, peer-reviewed dental literature. MTA materials are derived from a Portland cement parent compound and have been demonstrated to be biocompatible endodontic repair materials, with its biocompatible nature strongly suggested by …

Bs News

Building Services Engineering

No abstract provided.

Bifidobacteria In Feces And Environmental Waters, Regina Lamendella, Jorge W. Santo Domingo, Catherine A. Kelty, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Bifidobacteria have been recommended as potential indicators of human fecal pollution in surface waters even though very little is known about their presence in nonhuman fecal sources. The objective of this research was to shed light on the occurrence and molecular diversity of this fecal indicator group in different animals and environmental waters. Genus- and species-specific 16S rRNA gene PCR assays were used to study the presence of bifidobacteria among 269 fecal DNA extracts from 32 different animals. Twelve samples from three wastewater treatment plants and 34 water samples from two fecally impacted watersheds were also tested. The species-specific assays …

Multimodal News Story Clustering With Pairwise Visual Near-Duplicate Constraint, Xiao Wu, Chong-Wah Ngo, Alexander G. Hauptmann

Research Collection School Of Computing and Information Systems

Story clustering is a critical step for news retrieval, topic mining, and summarization. Nonetheless, the task remains highly challenging owing to the fact that news topics exhibit clusters of varying densities, shapes, and sizes. Traditional algorithms are found to be ineffective in mining these types of clusters. This paper offers a new perspective by exploring the pairwise visual cues deriving from near-duplicate keyframes (NDK) for constraint-based clustering. We propose a constraint-driven co-clustering algorithm (CCC), which utilizes the near-duplicate constraints built on top of text, to mine topic-related stories and the outliers. With CCC, the duality between stories and their underlying …

Digestion Of Sand-Laden Manure Slurry In An Upflow Anaerobic Solids Removal (Uasr) Digester, Khursheed Karim, Rebecca Hoffmann, M. (Muthanna) H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Studies on the Performance of a Laboratory Scale Up flow Anaerobic Solids Removal (UASR) Digester Were Carried Out using Sand-Laden Cow Manure Slurries Having Total Solids (TS) Concentration as 50 and 100 G/l. Hydraulic Retention Time (HRT) Was Maintained as 32.4 Days, Which Resulted in the Volatile Solids (VS) Loading Rates of 1 and 1.64 G/l D. the UASR System Was Designed to Remove Sand from the Manure Slurry, While Anaerobically Digesting Biodegradable Solids Inside a Single Reactor. to Enhance the Contact of Microorganisms and Substrate, the Liquor from the Top of the Digester Was Recirculated through the Bed of …

Changing Training Needs Arising From The Introduction Of Off-Site Construction Techniques, Louis Gunnigan, John Mcdonagh

Conference papers

The objective of this paper is to examine the changes in training needs arising from the increase of off-site construction in the Republic of Ireland. The methodology employed was a case study using a participant observation research technique. For a period of three weeks, the researcher observed the construction of residential housing, constructed using off-site techniques. From the practices observed and from interviews with the operatives on-site, an account of the differences in skills required between those employed in traditional construction and off-site construction was compiled. Each of the different trades involved in traditional construction was addressed and a comprehensive …