Engineering Commons^™

An Experimental Study For The Effect Of Specimen Size On Shear Behavior Of Granular Materials, Clifton Linwood Parker Iv

Civil & Environmental Engineering Theses & Dissertations

An experimental study was undertaken to look into the effect of specimen size on the volumetric behavior of granular triaxial specimens. It was hypothesized that the specimen preparation mold creates a unique particle arrangement near the perimeter of the specimen and thus, for smaller specimen diameter relative to the particle size, it will exhibit a greater effect of the unique particle arrangement on the volumetric behavior. particles was used A single distribution of spherical glass throughout the testing. The tested specimens were 3.6, 2.8, 2.0, 1.4, 1.0, and 0.6 inches in diameter with a fixed two to one specimen height …

Transient Simulation Of A Trombe Wall Passive Heating System Coupled To A Thermally Stratified Room, Ali Saleh Kheireddine

Mechanical & Aerospace Engineering Theses & Dissertations

Thermal performance of a Trombe-wall space heating system has been studied numerically for one-day and multiple-day periods. This study analyzes the system performance by simultaneously considering the coupled nature of the channel convection, wall heat conduction and transient room energy balance. A computer program has been written and implemented to assess the effects of system parameters, weather conditions and peak temperature control strategies on the system performance.

The system performance is influenced by such system parameters as the storage wall thickness, channel width and the temperature stratification in the room. Increasing the wall thickness decreases the temperature swings considerably, but …

The Effect Of Contacts On The Performance Of Electron-Beam Controlled Gaas And Diamond Switches, Michael Kevin Kennedy

Electrical & Computer Engineering Theses & Dissertations

The performance of GaAs and diamond as electron-beam controlled closing and opening switches has been studied. An emphasis has been placed on the effect of contacts on the current-voltage characteristics. The two materials studied were GaAs and diamond. Using the same semi-insulating GaAs wafer as a source of material, a bulk device and a p-i-n device have been fabricated and compared. The asymmetry of the pin diode allows operation at higher voltage because of the ability to suppress the lock-on effect. Whereas GaAs was ionized through cathodoluminescence; diamond, in the form of thin films, has been directly ionized by the …

Structural Characterization Of Fucoidan And Its Role In The Hemizona Assay, Manish S. Patankar

Chemistry & Biochemistry Theses & Dissertations

Fucoidan is a polysaccharide commonly found in brown algae. It is a sulfated polymer of the monosaccharide L-fucose. Fucoidan is thought to function in water retention by algae. Commercially available fucoidan is extracted from a brown algae called Eurus vesiculosus.

This polysaccharide has immense potential as a biologically active agent: (i) it exhibits anticoagulant action, (ii) it has also been reported to block retroviral replication and (iii) it is capable of blocking sperm-egg binding in sea urchin, mouse and rabbit. Recently, fucoidan has also been shown to block the interaction of human sperm and egg in the hemizona assay …

Retention Of Cellular Viability And Growth Potential In Cryopreserved Bovine Arterial Tissue: Implications For Clinical Use Of Cryopreserved Vascular Allografts, Kip G. Gardner

Biological Sciences Theses & Dissertations

Segments of bovine calf aortas and pulmonary arteries were cryopreserved at -196° C for two weeks to 18 months and subsequently thawed. Cellular morphology, viability, and growth potential in these segments were then compared with the same attributes in segments from fresh (control) arteries. Scanning electron microscopy revealed no disruption of intimal surfaces attributable to cryopreservation. Endothelial cells were successfully cultured from all cryopreserved arterial segments. Endothelial monolayers grown from cryopreserved arteries had a cobblestone appearance and expressed Factor VIII antigen but not smooth muscle alpha-actin. Plating efficiency in primary cultures of endothelial cells was lower for cryopreserved arteries than …

The Effects Of Automation On Crew Coordination In The Corporate Cockpit, Yves P. Koning

Master's Theses - Daytona Beach

The implementation of automated systems in the cockpit has somewhat changed pilots' working environment. The present study, which focus is on corporate aviation, looks at the influence automation has on crew coordination.

A questionnaire including both Likert scale and open-ended questions was sent to 880 qualified pilots. A descriptive as well as an inferential analysis of the data provided by the Likert scale questions was conducted. Out of the five variables tested, the only one to generate any significant differences (p

Overall, pilots pointed out the importance of verbal communication and cockpit resource management training, emphasizing the strong need for …

An Analysis Of The Potential Use Of Red Horse Capabilities And Training Activities To Perform Or Accelerate Air Force Environmental Cleanups, E. Alexander Stokes Iii, Randy A. Carpenter

Theses and Dissertations

There are more than 4,000 Air Force (AF) sites requiring restoration due to hazardous waste contamination. The AF goal is to completely restore all sites by 2000. One method of achieving this ambitious goal is to use in-house capabilities. This study examined the potential use of RED HORSE capabilities and training activities to assist with cleanup of contaminated sites. RED HORSE capabilities and training requirements were compared to the primary cleanup needs of the AF. One finding of this study suggests cleanup of sites contaminated by volatile organic chemicals (VOCs) is the primary need of the AF. The findings also …

A Study In Use And Management Of De/Anti-Icing Constituents With Regard To New Storm Water Legislation, Darren P. Gibbs, Bruce L. Willing

Theses and Dissertations

This research identified management practices of airfield and aircraft de/anti-icing constituents which may be implemented to deal with new storm water legislation. Storm water regulations require that deicing operations obtain a NPDES permit for discharges into storm water runoff which may mandate the use of Best Management Practices. An FAA civilian airport survey and a USAF survey were used, with a literature search, to identify practices of de/anti- icing constituents. Four major constituents are used-glycol, urea, calcium magnesium acetate, and sodium formate. Concerns of uncontrolled release of the constituents include high BOD rates, nitrate and nitrite enrichment, impaired aesthetic water …

Development Of A Heuristic Knowledge Base For The Selection Of Applicable Or Relevant And Appropriate Environmental Requirements, Scott J. Borg, Gerald B. Puetz

Theses and Dissertations

Applicable or Relevant and Appropriate Requirements (ARARs) are the basis used in establishing threshold limits for hazardous waste cleanups performed under the Comprehensive Environmental Response, Compensation and Liability Act (CERCIA). ARARs selections must be applied consistently at numerous cleanup locations concurrently. The purpose of this research was to analyze activities required for the development of a heuristic knowledge base used for selection of The problem domain for the research was limited CERCLA cleanups of contaminated groundwater, through the use of a pump and treat strategy, using air stripping as the as the cleanup technology. The research examined literature concerning the …

An Assessment Of The Options Available To Air Forces' Commanders To Suppress Smoke From Oil Well Fires, William B. Owens, Richard D. Taylor

Theses and Dissertations

The particulates in smoke from oil well fires can obscure targets and inhibit the use of precision-guided munitions. The purpose of this research was to develop a decision support matrix to aid commanders of air forces select methodologies for controlling oil well fire smoke through fire suppression. Through interviews with military experts and fire-fighters, a set of situational factors affecting the employment of these technologies was developed. Technologies for extinguishing oil well fires were investigated by conducting expert interviews and studying research data, periodical literature, and proposals suggesting means to control the Kuwaiti oil well fires. Over 200 proposals from …

Development Of The Air Module For The Work Information Management System. Environmental Subsystem (Wims-Es), Robert A. Cantwell, Jonathan S. Davis

Theses and Dissertations

The primary objective of this research was to develop the air module for the Work Information Management System Environmental Subsystem (WIMSES). The air module will provide Air Force environmental managers with a management information system (MIS) to control the growing amount of air pollution data required to stay in compliance with the newly amended Clean Air Act. To develop the air module, the Air Force's air pollution management requirements were researched first. These requirements were then compared to the capabilities of existing air pollution MISs used in the Department of Defense, the Environmental Protection Agency, and in commercial industry. The …

Cultural Resources Management In The United States Air Force: Development Of A Planning Primer, Steven R. Becker, Russell R. Hula

Theses and Dissertations

The purpose of this study was to produce a USAF base-level primer for use as a guide to requirements, standards, and procedures concerning the preservation of cultural resources. Cultural resources include buildings, sites, districts, structures, and objects that have significant scientific, historic, or cultural value. The research had two major objectives: (1) Identify existing sources of cultural resource information through a review of legal requirements, regulations, USAF policy documents, and other sources such as data bases. (2) Produce a 'cultural resources management primer' after identifying the appropriate characteristics of a primer. This product could then be used by novice personnel …

Demonstrating The Effects Of Shop Flow Process Variability On The Air Force Depot Level Reparable Item Pipeline, Marvin A. Arostegui Jr., Jon A. Larvick

Theses and Dissertations

This study investigated the effects of reducing the mean processing time and variability in the Shop Flow Segment of the Depot Level Reparable Item pipeline. The measure of interest was the average number of units in the pipeline of a particular type of item (referred to as the average pipeline contents). A literature review revealed that process variability in the pipeline has an impact on its effective operation and cost. A simulation model was developed to determine if reducing mean processing time and/or variability in the Shop Flow Segment would result in a reduction in the average pipeline contents. The …

An Evaluation Of Schedule Metrics Used Within Aeronautical Systems Center, Robert J. Hayes, Lawrence M. Miller

Theses and Dissertations

This study focused on a selected group of schedule metrics in use at Aeronautical Systems Center (ASC) acquisition program offices. Over 300 metrics were collected from the System Program Offices (SPOs). The metrics data were sorted into the categories of cost, schedule, and performance. In order to narrow the scope of the project, the team decided to focus on schedule metrics. Seven of the most common schedule metrics were selected for evaluation by a group of five experienced acquisition professionals. The group was asked to input the likely behaviors driven by the metrics being addressed by the study. Next, they …

Review Of Factors Impacting Warranty Cost-Benefit Analysis For The Sensor Fuzed Weapon System, Donna E. Kehrt

Theses and Dissertations

The purpose of this research effort was to identify factor that affect the warranty cost-benefit analysis for the Sensor Fuzed Weapon (SFW) system since an essential performance requirement (EPR) warranty waiver was under consideration. Defense funding has become scarce, and the limited dollars must be spent wisely. A cost-benefit analysis should provide a relevant projection of cost-effectiveness based on the best available data. The SFW and other dormant weapon systems present difficulties in determining cost- effectiveness because the systems most probably will be non-operating, non- reusable, and non-restorable. Three recommendations were made, relevant to dormant weapon systems, that pertained to …

Design Of An Artificial Neural Network Based Tactile Sensor For The Utah/Mit Dexterous Hand, Jeffery D. Nering

Theses and Dissertations

The Neural Tactile Sensor (NTS) is a high resolution, easily manufactured tactile sensor consisting of electrodes, a thin resistive 'skin', and pattern recognition circuitry that is capable of resolving dynamic and static contact location, force, and slip throughout the continuum of the sensor's active region. The sensor operates by means of a resistive 'skin' harboring the electric field generated when a current is injected into it, and a plurality of electrodes for taking measurements of said electric field. When current flows through the resistive medium from the location of tactile contact, an electric field within the resistive medium is established, …

Prioritizing Pollution Prevention Projects Using The Displaced Ideal Model For The Allocation Of Limited Funds, Scott W. Mcpherson, Debra J. Watts

Theses and Dissertations

This research developed a model to prioritize pollution prevention projects for the distribution of limited financial resources. This model was designed for use at the major command (MAJCOM) level. Each MAJCOM is allowed to select the attributes believed to be most appropriate for evaluating pollution prevention projects. The system also allows the flexibility for MAJCOMs to weight the attributes in accordance with requirements. The model uses "fuzzy logic" and the Displaced Ideal Model (DIM) to prioritize projects that currently do not have an imminent compliance deadline, but are important due to potential noncompliance with future regulations. These projects also are …

Output Frequency Changes In A Commercial Rubidium Clock Resulting From Magnetic Field And Microwave Power Variations, Edward B. Sarosy

Theses and Dissertations

This report shows the relationship between output frequency shifts and the absorption cell magnetic field during microwave power fluctuations on a commercial rubidium frequency clock. Changes in the clock output frequency relative to the 10 MHz reference were monitored as changes in the absorption cell magnetic field (0.01 to 1.0 Gauss) and changes in the cell's interrogation microwave power were varied from the nominal specification (PO) at four discrete values (+1.3. -1.1, -2.2, -4.OdB). The maximum normalized output frequency shift of 1.4x10^-10 occurred at--4dB. The maximum normalized frequency change for the +1.3 and -1.1 dB data is about 3 …

A Model For Determining Modular Heat Recovery Incinerator Feasibility On Air Force Installations, Arthur H. Anderson Jr., Paul R. Munnell

Theses and Dissertations

This study constructed a model to determine the feasibility of building municipal solid waste (MSW) fired modular heat recovery incinerators (HRIs) on Air Force installations. The model consisted of three gates. Gate one identified current federal regulatory air emission requirements for various HRI pollutants. It also specified two air pollution control configurations with emission reduction efficiencies capable of achieving these requirements. Gate two presented a life-cycle cost (LCC) economic analysis methodology. Operational and cost data for existing modular HRIs located in the United States facilitated the development of regression equations that estimate capital and annual operating costs for a modular …

Analysis Of Standard Type Unit Development, Jeffrey M. Hess, Merry D. Wermund

Theses and Dissertations

This research study examined the standard type unit development process for the Air Force. Current standard type unit development procedures were determined by a literature review. The literature review, with the interviews, provided information regarding the history of, purpose for, and possible alternatives for developing standard type units. A Delphi questionnaire was developed to determine how well the current process works, how standard type units worked for Desert Shield/Storm, and possible ways to improve the development process. This questionnaire was distributed to F-15 units, F-16 units, and major command personnel in Tactical Air Command (now Air Combat Command). All three …

A Comparison Of Computer And Paper Media In Psychological Testing, Anthony C. Hensley, Timothy R. Morris

Theses and Dissertations

This study examined differences based on computer and paper modes of administration in psychological testing. The hypotheses tested were the expectations that scores on the computer Wonderlic Personnel Test (WPT) would be higher than the paper version and subjects would report higher levels on the computer Vocational Preference Inventory (VPI) scales. A counterbalance experimental design with two experimental groups was used. The subjects were volunteers from the Air Force Institute of Technology (AFIT) and Wright State University (WSU); 90 subjects completed the study. This included 75 students from AFIT and 15 from WSU; 69 subjects were male and 21 were …

Risk Identification In Major Weapon Systems Acquisition In The Republic Of China Air Force, Te-Lung Tsai

Theses and Dissertations

This research examined the magnitudes of the performance, supportability, life-cycle cost, schedule, and management risk factors in current Republic of China Air Force (ROCAF) weapon systems acquisition programs and analyzed the risk drivers with respect to those risk factors. Mid-to-high level managers in the ROCAF and Chung-Sun Institute of Science and Technology (CSIST) were surveyed to determine the extent to which various risk factors were contributing to program risk. A total of fifty-four (54) managers responded to the survey. The results indicate: high risks to performance, supportability, life cycle cost, and schedule, and moderate risk to management. Risk-drivers that contributed …

An Analysis Of Strategic Planning To Support The United States Special Operations Forces' C3 Interoperability, George M. Pierce Ii

Theses and Dissertations

The purpose of this study was to analyze the strategic plans of USSOCOM to determine its role in resolving the C3 interoperability issues. A model using strategic controls and Theory of Constraints was used as a standard to evaluate USSOCOM's management plans. A literature search revealed that hardware and new technology were the primary concerns of previous studies. However, the literature did not address whether the lack of a formal strategy contributed to the C3 interoperability problems. Therefore, the determination was to adopt a fresh approach to the C3 interoperability issues and analyze the strategic process. The data analysis of …

The Theory Of Constraints Applied To Project Scheduling: The Critical Chain Concept Defined, Andrew D. Ingram, Paul E. Scherer

Theses and Dissertations

This research applies the Theory of Constraints' principles to a project management environment. The Constraint Theory developed by Dr. Eliyahu M. Goldratt has been successfully applied in many manufacturing settings. Researchers are now beginning to apply Theory of Constraints' principles and techniques outside the manufacturing environment. Specific objectives of this research effort include: to develop and demonstrate a resource constrained project scheduling algorithm based on the Theory of Constraints' principles and techniques: to perform a detailed comparison of the manufacturing and project scheduling environments designed to support algorithm development; and to lay the foundation for additional research in this area …

Risk Reduction As A Criterion For Measuring Progress Of The Installation Restoration Program, Scott Edwards Jr.

Theses and Dissertations

To properly manage the Installation Restoration Program (IRP) in the future, the Air Force (AF) needs a method to assess progress based on improvements in environmental conditions. An integral part of evaluating progress toward protecting human health and the environment is the assessment of risk reduction as a result of cleanup actions. The AF currently uses the Defense Priority Model (DPM) to assist in setting priorities for funding remedial actions at IRP sites. The DPM provides a numerical score for IRP sites representing the relative potential risk based on the environmental conditions at a site before remedial actions are taken. …

Issues Affecting Acquisition Strategies For Remedial Action Projects At Installation Restoration Program Sites, John E. Keoshian, William A. Kolakowski

Theses and Dissertations

Most, if not all, of Air Force IRP restoration work is accomplished through contracting avenues. The present system of cleanup and close out of these IRP sites is inefficient, time consuming, and costly. Expedient cleanup of contaminated sites will depend in large part upon on how effectively the USAF manages its restoration contracts. Difficulties are encountered due to differences in interpretation and/or vagueness of contracting and environmental information by all parties involved. Additionally, numerous conflicts arise when different agencies apply different acquisition strategies to similar remedial actions. To compound the problem, there are few definitions and little guidance from the …

A Model Action Plan To Reduce The Use And Release Of Cfcs In Air- Conditioning And Refrigeration Systems, David W. Andrews, Daniel P. Ellert-Beck

Theses and Dissertations

This study investigated methods to reduce the use and release of chlorofluorocarbon (CFC) refrigerants and evaluated alternatives to CFCS in air- conditioning and refrigeration systems. A life cycle cost (LCC) analysis formed the basis for evaluation. A literature review examined applicable CFC directives, containment methods, replacement refrigerants, and alternative processes. The results of the LCC analysis showed that maintaining the existing CFC system was always the least costly alternative. When forced to replace a CFC reciprocating package unit, the best replacement was a non-CFC reciprocating unit. The most practical replacement for reciprocating chillers was a new reciprocating chiller for systems …

A Methodology For The Characterization And Management Of Nonpoint Source Water Pollution, David M. Praner, Gordon M. Sprewell

Theses and Dissertations

The purpose of this research was development of a methodology for characterization and management of Nonpoint Source (NPS) water pollution. Section 319 of the 1987 Water Quality Act requires states to develop management programs for reduction of NPS pollution via Best Management Practices (BMPs). Air Force installations are expected to abide by federal, state, and local environmental regulations. Currently, the Air Force does not have a methodology to identify and quantify NPS pollution, or a succinct catalog of BMPs. Air Force installation managers need a package to assist them in meeting legislative and regulatory requirements associated with NPS pollution. Ten …

A Technical And Practical Study Of Composting As A Solid Waste Management Alternative For The Air Force, Donald R. Abrams, Timothy D. Brecheen

Theses and Dissertations

This thesis reviews composting as a solid waste management option for the Air Force. The Air Force's Pollution Prevention Program Mandates composting as an opportunity to reduce landfill disposal and save future environmental costs. This research considers composting technologies used in mixed municipal solid waste and yard waste applications. The thesis presents technical aspects of composting and also summarizes operational techniques of successful composting sites across the United States. Composting is a biological process for converting organic waste into a stable product for use as a soil amendment or mulch. The Air Force should immediately begin yard waste composting programs …

A Comparison Of Aircraft Maintenance Organizational Structures, Wesley C. Davis, Sanford Walker

Theses and Dissertations

This study compares the aircraft maintenance structure being implemented by General Merrill A. McPeak with that of the previous structure typified by TACR 66-5. Historical aircraft data is used to compare organizational structures. Data from the USAF and USN is used to build regression models to determine if organizational structure contributes to combat capability. Statistical tests are used to determine if a significant difference exists between the two organizational structures. Regression analysis and comparison of the results lead the researchers to conclude that a significant difference exists in the performance measures of COMO and Objective Wing organizations. While many reasons …