Engineering Commons^™

Mass Transfer And Benzene Removal From Air Using Latex Rubber Tubing And A Hollow-Fiber Membrane Module, Mark W. Fitch, Jeffrey Neeman, Ellen England

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A Dense-Phase Latex Rubber Tube and a Polyporous Propylene Hollow-Fiber Membrane Module (HFMM) Were Investigated for Control of Benzene-Contaminated Gas Streams. the Abiotic Mass Flux Observed through the Latex Tube Was 3.9-13 Mg/(Min·m2) for 150 Ppm of Benzene at Various Gas and Liquid Flow Rates, While a 100-Fold Lower Mass Flux Was Observed in the HFMM. after Seeding with an Aromatic-Degrading Culture Enriched from Activated Sludge, the Observed Removal Was 80% of 150 Ppm, Corresponding to a Mass Flux of 45 Mg/(Min·m2). the Observed Mass Flux through the HFMM during Biofiltration Also Rose, to 0.4 Mg/(Min·m2). Because the HFMM Had …

Flight Physician - March, 2003, Civil Aviation Medical Association

Browse all Civil Aviation Medical Association Newsletters

A twenty page newsletter of the Civil Aviation Medical Association. The newsletter provided news about civil aviation medicine and information related to the organization.

Natural Convection And Solid Phase Combustion, S. E. Whitney, Hendrik J. Viljoen

Papers in Reaction Kinetics

Self-propagating high-temperature synthesis [SHS] is a combustion process involving two or more solid reactants. The typical SHS configuration consists of a cylindrical preform of mixed powders, placed in an inert gas chamber, and ignited at one end. In past studies, interaction between the solid phase and the ambient gas phase has been limited to heat losses from the solid; the influence of natural convection on the solid phase has never been considered. In this study, computational fluid dynamics [CFD] is used, and it is shown that intense convection flow develops in the proximity of the combustion front. Gas flows adjacent …

Effective Thermal Conductivity Estimates Of Particulate Mixtures, Christiaan Richter, Hendrik J. Viljoen, N.F.J Van Rensburg

Papers in Reaction Kinetics

Several theories have been advanced to estimate effective thermal conductivities of particulate mixtures, but most theories have focused on the dilute case. A method is proposed to estimate the effective thermal con-ductivity coefficient of mixtures of arbitrary concentration. Earlier the authors developed a theory to deter-mine the expected contact area between different species. This theory is employed to determine the Kapitza resistance of the heterogeneous mixture and forms part of an overall theory to estimate the effective thermal conductivity. Results are compared with other theoretical estimates and with experiments.

Use Of Fuzzy Expert's Information In Measurement And What We Can Gain From Its Application In Geophysics, Leon Reznik, Vladik Kreinovich, Scott A. Starks

Departmental Technical Reports (CS)

The paper considers the problem of measurement information fusion from different sources, when one of the sources is an information about approximate values of the measured variables or their combinations. The information is given with fuzzy models and is used in combination with the measurement results. The properties of the modified estimates are studied in comparison with the conventional ones. The conditions when an expert's information application can give a high gain are derived, the gain value is estimated, the recommendations to an expert on making predictions are given. The possible gain in measurement result efficiency in geophysical applications is …

Kolmogorov Complexity: How A Paradigm Motivated By Foundations Of Physics Can Be Applied In Robust Control, Vladik Kreinovich, Issak A. Kunin

Departmental Technical Reports (CS)

Born about three decades ago, Kolmogorov Complexity Theory (KC) led to important discoveries that, in particular, give a new understanding of the fundamental problem: interrelations between classical continuum mathematics and reality (physics, biology, engineering sciences, ...). Crudely speaking, it enables us to better distinguish between mathematical possible (possible abnormal) and physically possible situations.

We show that this formalization is not only in good accordance with theoretical physics, but it can also be applied to robust control: instead of requiring that the control work for all mathematically possible situations, we only require that the control works for all "non-abnormal" situations.

Kentucky Highway Rating System, Doug Kreis, Lenahan O'Connell

Kentucky Transportation Center Research Report

This study had two goals: 1. Formulate a new method for generating roadway adequacy ratings; 2. Construct an appropriate data set and then test the method by comparing it to the results of the HPMS-AP method. The recommended methodology builds on the previous methodology, the HPMS-AP. However, the recommended differs from the HPMS-AP in that it incorporates crash data into the adequacy rating and increases the relative weight given to indicators of roadway safety for the appropriate functional classification of highways. The software for the proposed highway rating system is in a format that permits "what if" scenarios. The comparison …

Interfacial Mixing In A Highly Stratified Estuary: 1. Characteristics Of Mixing, David J. Kay, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

This article is Part I of a set of papers addressing mixing in a highly stratified estuary. Measurements of interfacial turbulence were made in Columbia River estuary under conditions of moderate river flow and neap tides. A flux correlation method was used to determine buoyancy fluxes, and fits to theoretical velocity and temperature variance spectra were used to measure turbulent kinetic and potential energy dissipation rates. At the measurement site in the interior of the estuary, mixing along the top of the salt wedge is found to occur only on ebb, during periods when the internal Froude number is supercritical. …

Cold-Formed Steel Top Load Bearing Tracks, Nahb Research Center, Inc.

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Acuta Enews March 2003, Vol. 32, No. 3

ACUTA Newsletters

In This Issue

Student Serves Spam on Tufts Network

e Portfolios.............................................. Jeanne Jansenius, Univ. of the South

Take a SIP of this lmportant Protocol........................................ Kevin Tanzillo, Dux Public Relations

Upcoming ACUTA Audio Seminars

ACUTA Member Sites to see

Expanded Eligibility for .EDU Domains

FCC Acts on Local Competition

DC Update...................................... Whitney Johnson, Retired, Northern Michigan Univ.

Survey Results...................................... Jeri Semer, CAE, Executive Director

Board Report...................................... John Bradley, Rensselaer Polytechnic Institute

Welcome New Members

The Development Of Relationships Between Constituent Concentrations And Generic Hydrological Variables, Carmen T. Agouridis, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

The collection and analysis of samples from storm events constitutes a large portion of the effort associated with water quality research. Estimating concentrations or loads from these events is often difficult. The equipment necessary to analyze the samples and the required laboratory resources are typically significant expenses incurred by the researcher. One potential method to reduce these costs is through the development of generic relationships between concentrations and easily measured variables such as dimensionless flow rate or time. The benefits recognized from such an effort include a reduction in the number of required samples, resulting in a reduction in cost. …

Inquisitive Pattern Recognition, Amy L. Magnus

Theses and Dissertations

The Department of Defense and the Department of the Air Force have funded automatic target recognition for several decades with varied success. The foundation of automatic target recognition is based upon pattern recognition. In this work, we present new pattern recognition concepts specifically in the area of classification and propose new techniques that will allow one to determine when a classifier is being arrogant. Clearly arrogance in classification is an undesirable attribute. A human is being arrogant when their expressed conviction in a decision overstates their actual experience in making similar decisions. Likewise given an input feature vector, we say …

Development Of An Experimental Test Section For Forcing Unsteady Flow In A Linear Compressor Cascade Using Circular Rods, Patrick C. Wade

Theses and Dissertations

Upstream propagating waves impinging on a cascade of compressor blades were examined in an effort to better understand the influence of downstream components on high cycle fatigue in turbine engines. An array of cylinders was used to simulate the unsteady field generated by a rotor downstream of a set of stators. The unsteady flow upstream of a single cylinder and an array of cylinders, with and without an upstream cascade, was examined experimentally and computationally. Computational results indicate that the cylinders would only shed coherently when placed downstream of a set of blades. Coherent shedding is created when each of …

Cold-Flow Testing Of A Subscale Model Exhaust System For A Space-Base Laser, Ian S. Bautista

Theses and Dissertations

The purpose of this research was to continue a study of gas-dynamic phenomena that occurred in stacked cylindrical rings of nozzles and an exhaust manifold as reported by Captain Scott Bergren in 2002. The rings and exhaust manifold were part of a 1/5-scale model of one quadrant of the conceptual Space Based Laser Integrated Flight Experiment (SBL IFX) gas dynamic laser. This model was mated to a blow- down/vacuum wind tunnel and consisted of a nozzle array, centerbody, supersonic diffuser, and a transition structure to mate the vacuum and test section. During Capt Bergren's research, supersonic flow was found to …

Experimental Demonstration Of An Algorithm To Detect The Presence Of A Parasitic Satellite, Vincent J. Dabrowski

Theses and Dissertations

Published reports of microsatellite weapons testing have led to a concern that some of these "parasitic" satellites could be deployed against US satellites to rendezvous dock and then disrupt, degrade disable or destroy the system. An effective detection method is essential. Various sensing solutions were investigated including visual, impact, and dynamic techniques. Dynamic detection, the most effective solution, was further explored. A detection algorithm was constructed and validated on the Air Force Institute of Technology's ground-based satellite simulator, SIMSAT. Results indicate that microsat microsatellites rigidly connected to a satellite can be detected with a series of small identical maneuvers utilizing …

Experimental Results For A High Swirl, Ultra Compact Combustor For Gas Turbine Engines, Ryan J. Quaale

Theses and Dissertations

Laser Doppler Velocimeter (LDV) experiments have been conducted within the cavity of an atmospheric pressure, small scale, Ultra Compact Combustor (UCC). The UCC uses highly swirled flow in a cavity around the outside periphery of the combustor to generate high centripetal acceleration in the fluid. This enhances mixing and leads to a very short axial flame length. Additionally, due to the circumferential velocity, much of the residence time required by the flame is provided by the circumference of the engine rather than axial length as in conventional combustors.

Nonlinear, Transonic Flutter Prediction For F-16 Stores Configuration Clearance, Raymond G. Toth

Theses and Dissertations

Wing flutter, or more accurately limit cycle oscillation (LCO), has been an issue for the F-16 since its operational deployment. Different store configurations and the permutations of those configurations after weapons are released will cause LCO to either disappear or appear. Unfortunately, the current method used by engineers for predicting LCO onset is based on linear, subsonic aerodynamic theory with no corrections for transonic effects. Predictions using this method are often good in frequency, but can be far off in predicting onset speed, forcing flutter engineers to rely more on experience and interpolation from similar configurations to design flight test …

Application Of Maneuver-Based Control In Variable Autonomy Unmanned Combat Aerial Vehicles, Alexander M. G. Walan

Theses and Dissertations

The rise in the capability and lethality of unmanned combat aerial vehicles (UCAVs) historically has been paralleled by an increase in the complexity of the command and control of these systems. This trend has continued with the command and control of the current fleet of unmanned aerial vehicles such as the Predator and Global Hawk. The control of these vehicles falls on the extremes on the manual vs autonomous spectrum. As the missions tasked to these vehicles increase in complexity and lethality, operators will increasingly require the ability to tailor the amount of control exercised over the vehicle. Maneuver Based …

Experimental And Computational Failure Analysis Of Graphite/Bismaleimide Laminated Composite And Carbon Foam In Sandwich Construction, Troy C. Welker

Theses and Dissertations

Sandwich beams consisting of a carbon foam core and graphite/bismaleimide face sheets were constructed and tested. Nine specimens were fabricated using three distinct cross-ply symmetric face sheet layups with a constant core thickness. Four-point bend testing controlled by a constant rate of midspan vertical displacement was used to load the specimens to failure. Displacements and strains from the experiment were compared to analytical sandwich beam theory and displacements and failure loads were compared to a layerwise finite element solution. A phenomenological failure criterion was developed that compares favorably with experimental failure data. The finite element solution gives failure within an …

Hybrid Control Strategies For Rapid, Large Angle Satellite Slew Maneuvers, David B. French

Theses and Dissertations

This research investigated hybrid control strategies for rapid satellite pointing. First, a detailed computer simulation model of AFIT's SIMSAT satellite simulator was constructed. Control strategies were developed to enable the system to perform large-angle, 3-axis slewing maneuvers using a combination of both thrusters and reaction wheels. To handle the non-linear model, a State Dependent Riccati Equation controller was programmed and successfully controlled the computer-modeled satellite for any given slewing maneuver. A simpler PD controller was then programmed and demonstrated on the computer simulation of SIMSAT, using a combination of thruster and reaction wheel control inputs for large-angle single axis maneuvers …

Development, Fabrication And Ground Test Of An Inflatable Structure Space-Flight Experiment, Thomas L. Philley Jr.

Theses and Dissertations

Inflatable, rigidizable structures provide a solution to reduce the costs associated with design, fabrication and launch of a space system while simultaneously increasing the deployment reliability and mission success of the system%. This research focused on the follow on design, fabrication, and ground test of the Rigidizable Inflatable Get-Away-Special Experiment (RIGEX). RIGEX is a self-contained experiment that will test the deployment and structural characteristics of three inflatable rigidizable tubes. Once inflated and rigidized, each tube will be excited using piezoelectric transducers in order to collect vibration data for structural characterization. The goal of this research was to collect ground testing …

Auto Carrier Transporter Loading And Unloading Improvement, Brian M. Miller

Theses and Dissertations

Thousands of vehicles (cars, trucks and vans) are transported every day from one location to another. These vehicles are moved around the country on Auto Carrier Transports (ACTs). Delivering these vehicles involves large quantities of time, money and energy. Any reduction in time and energy will result in a significant savings of money. The intent of this research is to develop an algorithm to solve the Auto Carrier Transport Pickup and Delivery Problem. In doing so, the focus is to limit the total times vehicles are placed on and taken off the carrier, otherwise known as the number of loads, …

A Simulation-Based Analysis Of The Impact Of In-Sourcing A Major Process Element On The Coast Guard Hh-601 Depot Maintenance Process, Steven E. Vigus

Theses and Dissertations

Leaders at the United States Coast Guard's Aircraft Repair and Service Center (ARSC) in Elizabeth City, North Carolina recently formalized their planning and analysis functions by adding a dedicated branch to their command structure. The Planning and Analysis Branch intends to apply computer modeling and simulation to study the impact of process changes to the various Programmed Depot Maintenance (PDM) lines. This research considers the applicability of this type of modeling and simulation, using ARENA to study the current HH-6OJ PDM process. The contribution of this research is a methodology specific to ARSC needs, an analysis of methodology based on …

Estimating Engineering And Manufacturing Development Cost Risk Using Logistic And Multiple Regression, John V. Bielecki

Theses and Dissertations

Cost Growth in Department of Defense (DoD) major weapon systems has been an on-going problem for more than 30 years. Previous research has demonstrated the use of a two-step logistic and multiple regression methodology to predicting cost growth produces desirable results versus traditional single-step regression. This research effort validates, and further explores the use of a two-step procedure for assessing DoD major weapon system cost growth using historical data, We compile programmatic data from the Selected Acquisition Reports (SARs) between 1990 and 2001 for programs covering all defense departments. Our analysis concentrates on cost growth in the research and development …

Performance Analysis Of Protocol Independent Multicasting-Dense Mode In Low Earth Orbit Satellite Networks, Mark D. Saeger

Theses and Dissertations

This research explored the implementation of Protocol Independent Multicasting - Dense Mode (PIM-DM) in a LEO satellite constellation. PIM-DM is a terrestrial protocol for distributing traffic efficiently between subscriber nodes by combining data streams into a tree-based structure, spreading from the root of the tree to the branches. Using this structure, a minimum number of connections are required to transfer data, decreasing the load on intermediate satellite routers. The PIM-DM protocol was developed for terrestrial systems and this research implemented an adaptation of this protocol in a satellite system. This research examined the PIM-DM performance characteristics which were compared to …

Internet Protocol (Ip) Over Link-16, Clinton W. Stinson

Theses and Dissertations

The purpose of Link- 16 is to exchange real-time tactical data among units of the United States and allied forces. Primary Link- 16 functions include exchange of friendly unit position and status data, fl%the dissemination of tactical surveillance track data, and the control/management of air, surface, and subsurface engagements. Because Link- 16 will play an integral role in fl% network-centric Joint Battlespace Infosphere (JBI), the performance of Internet Protocol version six (IPv6) and IP Security (IPSec) over Link-16 needs to be determined. Using OPNET modeling software to simulate a Link- 16 network, the investigation of this research revealed that the …

Using Future Value Analysis To Select An Optimal Portfolio Of Force Protection Initiatives, Robert P. Eskridge

Theses and Dissertations

With the recent increase in terrorist activity, force protection has become a key issue for the Department of Defense, Leading the research for new ideas and concepts in force protection for the US Air Force is the Air Force Force Protection Battlelab (FPB). The FPB is charged with searching out force protection ideas and selecting those most worthy for future consideration. In 2002, a Value-Focused Thinking (VFT) hierarchy was created to help the FPB select those ideas that provided the most value to the Air Force and its force protection goals. This research effort uses the Future Value Analysis (FVA) …

Long Term Implementation Of A 100 Percent Checked Baggage Screening System: A Value Focused Thinking Approach, Quincy Meade

Theses and Dissertations

The terrorist attacks of 11 September 2001, carried out via aircraft hijackings, clearly demonstrated the massive destruction potential when vulnerabilities in the aviation system are exploited. Airport security measures have since been strengthened and new measures have been set in place. With the passage of the Aviation Transportation and Security Act (ATSA) of 2001 the checked baggage systems at U.S. Airports are now required to screen all checked bags with explosive detection devices. This is a significant increase from the small percentage of bags that were previously screened. The original 2009 deadline was changed to 31 December 2002 and this …

Optimizing An In Situ Bioremediation Technology To Manage Perchlorate-Contaminated Groundwater, Mark R. Knarr

Theses and Dissertations

Combining horizontal flow treatment wells (HFTWs) with in situ biodegradation is an innovative approach with the potential to remediate perchlorate-contaminated groundwater. A technology model was recently developed that combines the groundwater flow induced by HFTWs with in situ biodegration processes that result from using the HFTWs to mix electron donor into perchlorate-contaminated groundwater. A field demonstration of this approach is planned to begin this year. In order to apply the technology in the field, project managers need to understand how contaminated site conditions and technology design parameters impact technology performance. One way to gain this understanding is to use the …

A Life Cycle Assessment And Economic Analysis Of Wind Turbines Using Monte Carlo Simulation, Edward J. Liberman

Theses and Dissertations

The United States depends heavily on nonrenewable fossil fuels to generate electricity. Using renewable energy sources, such as wind, could reduce air emissions and fossil fuel dependency. Previous studies have examined the life cycle costs and environmental impacts of using wind to generate electricity, but results have varied due to inconsistent modeling assumptions. This research uses Monte Carlo simulation to conduct an economic payback analysis and life cycle assessment of 11 modern, utility-scale wind turbines. Hourly meteorological data was used to evaluate 239 U.S. locations. For each location, the wind turbine with the shortest median payback period was assumed to …