Engineering Commons^™

Texture And Young’S Modulus Of Nickel/Gamma-Alumina Composites, Abdulaziz Alamr

Masters Theses

To improve Young's modulus of 2024-T3 rolled aluminum specimens, it was electroplated with nickel reinforced with nano-particles of γAl₂O₃. Taguchi method was used to investigate the effect of coating variables, which were current density, coating time, and mixing rate, on the coating thickness. The coatings were tested for crystallographic texture, using pole figures of (200) and (111) for nickel and (400) for γAl₂O₃. Surface topography was measured using WYKO Vertical Interference Microscope. The crystallographic texture of nickel in the coating depended on the coating conditions. A universal testing machine was- used to …

Residual Stress And Wear Resistance Of Composite Coatings Of Nickel/Gamma-Alumina, Khaled Abdulrahman Al-Ogab

Masters Theses

Nickel reinforced with nanoparticles of γ−Al₂O₃ have been successfully codeposited on 2024-T3 cold rolled aluminum alloy by electrodeposition with direct current. The effects of current density, particle concentration in the nickel sulfamate bath, air agitation, and coating time on Ni/γ−Al₂O₃ composite have been investigated. The residual stresses and wear resistance of the Ni/γ−Al₂O₃ composite have been measured using X-ray diffractometer and pin-on-disk techniques respectively. The residual stress and wear resistance behavior of the composite were compared with those of nickel-only deposits. An annealed ground nickel, which was mechanically removed from the …

Determination Of Anisotropy Of Granular Materials And Its Relation To Liquefaction Resistance Under Cyclic Loading, Omer Faruk Capar

Civil & Environmental Engineering Theses & Dissertations

Granular materials such as sand deposits have anisotropic characteristics due to the gravitational forces during depositional process and various stress histories. These anisotropic characteristics make evaluation of liquefaction resistance of soil very complex. Since obtaining undisturbed soil specimens for laboratory tests from discrete elements like sandy soils is very laborious, the soil specimens are reconstituted in laboratory with regards to the in-situ density of soil. Reconstituting the soil changes the soil fabric or anisotropic characteristics in comparison with field conditions. Many researchers have pointed out that liquefaction resistance is highly influenced by differences in the structure of the soil (or …

Feasibility Study To Extract Iron And Chromium From Chromium Contaminated Soils, Wiwat Kamolpornwijit

Dissertations

Chromium contaminated soils, besides being recognized for toxic and hazardous hexavalent chromium, contain high iron concentrations. At some sites, concentrations of iron oxide are higher than 30%. Both iron and chromium in soils have recyclable value provided they can be either concentrated in the oxide form or separated as metal. The concentrated oxide can be used as a substitute for the iron ore. The extracted metal can also be recycled in the steel industry. The objective of this study is to study the feasibility of extracting iron and chromium from soils.

Chromium contaminated soils, can be classified into two groups, …

A Delay Model For Exclusive Right-Turn Lanes At Signalized Intersections With Uniform Arrivals And Right Turns On Red, Mohammad A. Qureshi

Doctoral Dissertations

Right turn on red (RTOR) is an established part of today’s driving patterns. However,despite several revisions of the Highway Capacity Manual (HCM), the procedures for estimating delay at signalized intersections do not adequately incorporate the effects of RTOR. The HCM currently removes RTOR from the analysis.

This dissertation has developed models of uniform delay that incorporate RTOR based on queuing theory. Queuing accumulation polygons (QAP) were developed that include RTOR. The research developed a classification system for describing any signal phasing into one of 4 classes based on the sequence of 3 red regimes and one green regime.

It was …

Formulation And Assessment Of A Customizable Procedure For Pavement Distress Index, Zongren Wang

Doctoral Dissertations

A customizable procedure for the formulation of Pavement Distress Index (PDI) based on human rating behavior is presented in this dissertation. This procedure formulates PDI as the maximum PDI value in a user-defined scale minus the Total Deduct Value (TDV), which is the sum of the product of each individual Deduct-Value (DV) and its corresponding weight. These weights, defined as a function of corresponding DV-percentages, i.e. individual DV over TDV, are identified using data simulated according to the studies by Sun and Yao (1991) and PAVER, a Pavement Management System (PMS) developed by the U. S. Army Corps of Engineers. …

Environmental Evaluation Of Incinerators In Egypt & Waste Management Of Ash, Aya Mohamed Lamei

Archived Theses and Dissertations

No abstract provided.

Validation Of Passive Air Sampling Monitors Onboard United States Navy Submarines, Larry A. Mcfarland

Community & Environmental Health Theses & Dissertations

An operating submarine creates a unique air quality mixture of compounds that result from a combination of human metabolism, construction materials, materials brought onboard and compounds created through the interaction of ship systems. A comprehensive study of submarine atmospheres is ongoing during deployments of U.S. Navy nuclear submarines. As part of the overall effort, a paired air sampling comparison field validation was conducted to compare the air sampling effectiveness of passive diffusive monitors compared to more traditional active air sampling methods when sampling for acrolein, formaldehyde and ozone in the enclosed submarine atmosphere. Acrolein monitors containing 2-hydroxymethylpiperidine (HMP) impregnated glass …

Cfmms – Computerized Facilities Maintenance Management System, Prawit Rotsawatsuk

Masters Theses

Computerized facilities maintenance management systems, previously available only to very large facilities, are now accessible to small and medium-sized maintenance organizations. Advertisements for such products promise reductions in maintenance costs. Where a manual system of maintenance management is currently employed, moderate reductions in maintenance costs and facility downtime are fully possible. Where no formal maintenance management procedures are present, the structure and case of a computerized maintenance system can result in dramatic cost reductions and improvements in facility availability. There are, however, practical limits to the applicability of computerized maintenance systems. The objective of any maintenance program is to minimize …

Intermodal Transit System Coordination With Dynamic Vehicle Dispatching, Md. Shoaib Chowdhury

Dissertations

In most urban areas where transit demand is spread widely, passengers may be served by an intermodal transit system, consisting of a rail transit line (or a bus rapid transit route) and a numbers of feeder routes connecting at different transfer stations. In such a system, passengers may need one or more transfers to complete their journey. Therefore, scheduling vehicles operating in the system with special attention to reduce transfer time can contribute significantly service quality improvements. In this study two models, one for coordination of a general intermodal. transit system and another for dynamic dispatching of vehicles on coordinated …

Multimedia Modeling Of Organic Contaminants In The Passaic River Watershed, Lansana Coulibaly

Dissertations

A dynamic fate and transport multimedia environmental model was developed and applied to assess the release of five priority contaminants in the Passaic River Watershed, including: napthalene, toluene, trichloroethylene, 1-1-1 trichloroethane and xylene. The model uses the current releases of contaminants as well as cross-boundary advection to determine the fate and environmental distribution of these chemicals in the watershed. The model was developed using a dynamic fugacity approach in order to allow for scenario analysis such as source reductions and no-action alternatives. This modeling effort is expected to achieve a comprehensive assessment of contaminants not only in the proximity of …

Stress And Thermal Analysis Of The Lotec Carrier, Scott Thomas

Honors Capstone Projects and Theses

No abstract provided.

Evaluation Of Factors Affecting Earth Pressures On Buried Box Culverts, Michael Zhiqiang Yang

Doctoral Dissertations

Factors affecting the earth pressures acting on buried box culverts under deep embankments were evaluated by field instrumentation and numerical analyses. Two instrumented cast-in-place concrete culverts were designed and constructed differently. Long term earth pressures under constant embankment height were observed after the completion of construction. Both observed earth pressures and those predicted by numerical analyses were compared with the current AASHTO earth pressure recommendations, as well as the AASHTO design pressures in effect at the time a failed box culvert was designed in the mid 1970s. Field measurements suggested that the previous AAHSTO design pressure (1977, 12th edition) significantly …

Recycling Pvc Wastes In Concrete Mixtures, Maged Lamei Naguib

Archived Theses and Dissertations

No abstract provided.

Static Lateral Load Testing Of Model Piles In Clay Soil Phase 1, Steven Douglas Dapp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research project was done on behalf of the Utah Department of Transportation (UDOT). Model piles were subjected to static lateral loading in homogeneous, undisturbed clay with a known undrained shear strength. The dimensions of length, diameter, height from soil to applied load, and a pile stiffness parameter as was determined by dimensional analysis to be consistent will common full-scale steel pipe piles commonly used by UDOT. Bending moment profiles of the model pile were obtained for Lateral loads using foil type strain gages. Pile head deflection and soil response (p-y curves) were determined from these measured pile moment profiles. …

Layer Properties Of Oriented Strandboard, Caryn Steidl

Masters Theses

It is well known that the density varies through the thickness of oriented strandboard, with the face being much denser than the core. Hence, the modulus of elasticity and the strength should vary through the thickness. To determine the variation in these properties through the thickness of the panel, a commercial oriented strandboard panel was sliced into fifteen layers to obtain specimens for tension and compression testing. Using multiple saw blades and spacers mounted on an arbor in a milling machine, thin specimens were obtained both perpendicular and parallel to panel length. The specimens were tested in tension using straight-sided …

Develop Design Data On Pressure Loss Of Large Pipe Fittings, Patrick Dent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pressure loss coefficients were determined for large radius ells, large concentric pipe reducers, and expansions, as well as large pipe tees. The fittings tested were 12, 16, 20, and 24 inch forged steel weld. Forty individual fittings from four different manufacturers were tested to determine loss coefficient values. Each test fitting was examined at a specified range of pipe velocities to determine mean and variation of loss coefficients. Tees were also examined for mean and variation of loss coefficients over a range of flow distributions.

Currently no data exists for pipe fittings of these larger diameters. This study will provide …

Internal Forces In A Reinforced Concrete Box Culvert, Scott Mitchell Wood

Masters Theses

In 1996, a reinforced concrete box culvert with approximately 19 meters of embankment fill was instrumented with strain gages and pressure cells to determine the internal forces applied to the culvert. Strain and pressure readings were taken for a period of 3 years during and after the construction of the embankment. From a knowledge of the culvert's dimensions and material properties, the strain readings were converted to forces and bending moments. These forces were then compared to the allowable criteria from the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications for Highway Bridges. A computer model of …

Estimating Life Loss For Dam Safety Risk Assessment, Duane Michael Mcclelland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

"Estimating Life Loss for Dam Safety Risk Assessment" explores the need for a new life-loss model in dam safety risk assessment, historical foundations on which that model can be built, and issues that are critical for a successful life-loss model to address. After critiquing existing life-loss models, the work presents a summary of historical insights that were derived by characterizing flood events on the level of subpopulations at risk, using nearly 100 carefully defined variables. Building upon both conceptual and historical insights, the work culminates by presenting the conceptual basis for a new life-loss model that remains under development.

Chapter …

Learning Reinforced Concreyte Design Principles Using A Java-Vrml Based Design Studio, Amarneethi Vamadevan

Masters Theses

Dynamics involving reinforced concrete design are the first real engineering course encountered by the undergraduate construction engineering students. Quite often its associated rigorous theories makes it an uninteresting academic hurdle for many below mediocre students. However when the theory is exemplified with multimedia, interaction and visualization techniques, the conceptual understanding is enhanced. The teaching methodology presented in this thesis is based on presenting students with an individualized, interactive and guided learning environment. The main elements of this approach are: a means of assimilating the student's interactive learning knowledge and behavior (user model), representation of the instructor's guidance and assessment knowledge …

Computational Investigation Of Stress, Contact Conditions, And Buckling Of Thin-Walled Pipe Liners, Meihuan Zhu

Doctoral Dissertations

Thin walled polymeric liners are often used to rehabilitate deteriorated pipe lines. The host pipes into which these liners are installed are typically assumed to be structurally sound, and the liner is only expected to carry the external pressure exerted by the groundwater. This external pressure will induce creep deformation and radial deflections that may eventually result in collapse of the liner within the host pipe. The aim of this work is use computational modeling to better understand the evolution of conditions leading up to collapse so that improved liner design models can be developed. Emphasis is placed on a …

Analysis Of The Air Force Iso 14001 Pilot Study Conducted By Dod, Rodney C. Harris

Theses and Dissertations

The Department of Defense (DoD) conducted an ISO 14001 pilot study with the primary goal of determining how ISO 14001 could help DoD organizations reduce risks, improve compliance with environmental regulations, enhance stewardship, contain costs, and meet emerging regulatory requirements. This thesis analyzed the pilot study, specifically looking at the ISO 14001 implementation at three Air Force installations participating in the study. The research objectives were to identify factors that affect implementation of ISO 14001, compare the implementation strategies used by the bases, and develop propositions for Air Force managers to consider when implementing ISO 14001. Interviews of key personnel, …

Cost Analysis Between Saber And Design Bid Build Construction, Elwood Henry

Theses and Dissertations

The purpose of this research was to perform a cost analysis between DBB and SABER construction. The research involved traveling to Wright-Patterson and Holloman Air Force Bases to gather project information on comparable projects completed by both methods. There were a total of 46 projects collected from both bases. A methodology was developed to compare the projects completed. Projects were divided into categories containing similar types of construction. Data from the project was then used to calculate a unit cost for the project. Project comparability was demonstrated by showing the projects constructed by each method completed a similar type and …

Effects Of Moisture Content In Solid Waste Landfills, Craig P. Eck

Theses and Dissertations

Solid waste landfills are an extremely complex and heterogeneous environment. Modeling the biodegradation processes within a landfill must involve an understanding of how environmental factors affect these processes. Arguably, the most important environmental factor influencing biodegradation processes is solid waste moisture content. This research effort, which is an extension of a system dynamics model previously presented by Colborn (1997) and amended by Benter (1999), attempts to understand and model the effects of moisture content on waste degradation and landfill gas generation. The new moisture structure that was added to the previous models provides a better representation of the impact of …

Modeling The Effect Of Nonlinear And Rate-Limited Sorption On The Natural Attenuation Of Chlorinated Ethenes, Peter P. Feng

Theses and Dissertations

Chlorinated solvents like tetrachloroethene (PCE) and trichloroethene (TCE) are the most common detected groundwater contaminants at Department of Defense installations in the United States. Unfortunately, technologies conventionally used to remediate chlorinated solvent-contaminated groundwater often fall short of achieving regulatory goals. Natural attenuation of chlorinated solvents offers an alternative remediation strategy that may achieve goals. However, the processes involved with natural attenuation are not fully understood, and this lack of understanding has hindered acceptance of natural attenuation by regulatory agencies. This study involved use of a numerical model that incorporated the physical, chemical, and biological processes thought to be relevant to …

In Situ Treatment Of Chlorinated Ethene-Contaminated Groundwater Using Horizontal Flow Treatment Wells, Derek R. Ferland

Theses and Dissertations

The limitations of conventional containment technologies for groundwater contaminated with chlorinated solvents have motivated development of innovative technologies to achieve national groundwater remediation objectives. One inn9vative technology that is currently under development involves metal reductants or catalysts to chemically destroy the dissolved chlorinated solvent. Models are important tools that can be used to help transition this technology to the field. Model studies can be used to gain understanding about the technology, help determine when the prospective technology might work for a given site, and design full-scale field applications.

Empirical Evaluation Of The Civil Engineer Career Pyramid And Career Guidance, Travis K. Leighton

Theses and Dissertations

Air Force civil engineer officers rely on published guidance to assist in establishing their career objectives. This thesis uses empirical data to evaluate the published Air Force career guidance. The data set is comprised of complete duty histories from all active duty lieutenant colonels in the civil engineer career field. The guidance implies a career path to become a civil engineer squadron commander but provides no empirical validation. This thesis follows a rigorous procedure to objectively evaluate the Air Force guidance. The guidance is translated into 24 research questions based on its main tenets. Each duty occurrence is categorized by …

The Influence Of Outsourcing On Job Satisfaction And Turnover Intentions Of Air Force Civil Engineer Company Grade Officers, James F. Kennedy

Theses and Dissertations

A survey was distributed to 865 active duty Air Force Civil Engineer company grade officers (CGOs) assigned to locations throughout the world. The survey was designed to assess the CGOs' current job satisfaction and their intentions towards making a career out of the Air Force. Additionally, the survey measured the CGOs' perceptions of outsourcing, and how they feel that it will influence the Civil Engineer career field. Relationships were evaluated between the perceptions of outsourcing and job satisfaction, and between job satisfaction and turnover intentions. Overall, Civil Engineer CGOs reported a slightly positive level of satisfaction and a negative perception …

Use Of Genetic Algorithms To Characterize Groundwater Contamination Source Areas, Chaz M. Williamson

Theses and Dissertations

In this work, genetic algorithms (GAs) were used to help interpret tracer breakthrough curves from partitioning interwell tracer tests (PITTs) conducted at Hill AFB, Utah by researchers from the University of Florida. Two transport models were developed to simulate tracer transport in the test cells. One model assumed the cell consisted of multiple layers, and that transport in each layer could he described by the one-dimensional advective/dispersive equation. The second model also assumed multiple layers, and modeled transport in the individual layers as advective transport through 100 tubes. Transport times were represented by a stochastic (lognormal) distribution. The model solutions …

Performance-Based Seismic Engineering Of Low And Medium-Rise Steel Frames, Saeid Rashidi

Dissertations

The performance level of low and medium-rise steel frames designed according to the common force/strength approach of the UBC or NEHRP is determined. Several combinations of soil profile type, lateral-force-resisting system, and frame-member proportioning are included in the designs.

To evaluate the expected damage, nonlinear models of the designed frames are subjected to a number of actual and simulated ground motion accelerograms and appropriate structural response parameters such as, interstory drift, ductility demand, and dissipated hysteretic energy are obtained. In addition, a modified form of Park-Ang damage index is calculated for moment-resisting frames. The seismic performance of the steel frames …