Engineering Commons^™

Tubería Petrolera Recurso Para La Construcción De Puentes, Diego Armando Leal Vargas, Wilmar Armando Jiménez Marulanda, Anderson Salvador Bernal Tello

Ingeniería Civil

No abstract provided.

Energy Efficiency In Cold-Weather High-End Custom Homes, Joseph R. Kearl

Theses and Dissertations

Nationally, there is increasing interest in energy efficient homes due to growing energy costs and increased awareness. However, many builders haven't yet incorporated energy saving products and practices into homes. Many builders don't have the resources to evaluate available options and prefer to rely on the experiences of other builders. The purpose of this study was to create energy efficiency benchmarks for cold-weather, high-end custom homes and evaluate current building practices. A list of energy-efficient products and practices was created through a review of relevant literature. A group of expert builders was formed into a committee to help determine energy …

Bulk Behavior Of Nanostructured Aluminum: Nanocrystalline Powders Compaction, Canning And Consolidation Via Intense Plastic Straining, Mohamed Mahmoud Hamed Shamma

Archived Theses and Dissertations

No abstract provided.

Evaluation, Comparison, And Design Of Two Experimental Bridges In Tennessee, Kyle Parker Scoble

Masters Theses

This thesis describes the design and evaluates the adequacy of the moment connection of an experimental two-span highway bridge designed by the Tennessee Department of Transportation. The Massman Drive bridge is an experimental design that unifies the construction economy of simple span bridges and the structural economy of continuous span bridges. The experimental connection, consisting of cover plates and kicker wedge plates, is used to connect the two adjoining girders over the center pier. As a result, the bridge is designed to function as a continuous bridge during the deck pour and behave compositely with the reinforced concrete deck under …

Guidelines For The Application Of Recycled Concrete Aggregate In The Egyptian Construction Industry, Ahmed Moustafa Essam Aly Kamel

Archived Theses and Dissertations

Construction industry is one of the most important fractions of economy worldwide. This industry consumes enormous amounts of raw materials and produces considerable waste. The optimization of construction material usage not only saves costs but also can significantly contribute towards sustainable development. The concept of recycling the construction and demolition rubble is being addressed in this study as a solution. The recycling of concrete, resulting from both the construction activities and the demolition activities, in order to be used as a source of aggregate is being focused upon in this study. Although the idea of using recycled concrete has been …

Comparing The Feasibility Of Cutting Thin-Walled Sections From Five Commonly Used Metals Utilizing Wire Electric Discharge Machining, Richard C. Stephenson

Theses and Dissertations

Wire Electric Discharge Machining (wire-EDM) is a non-traditional machining process. Controlled electric sparks are successively used to vaporize part of a workpiece along a programmed path in order to machine a desired part. Because there is no tool that comes in direct contact with the workpiece, it is possible to machine thin, delicate parts. This thesis was designed to observe and analyze the differences in cutting capabilities for a conventional wire-EDM machine when cutting thin-walled sections from five commonly used metals utilizing a variation of roughing and finishing passes. The five metals that were used in this study are: Aluminum …

Friction Stir Welding Of High-Strength Automotive Steel, Eric Michael Olsen

Theses and Dissertations

The following thesis is a study on the ability to create acceptable welds in thin-plate, ultra-high-strength steels (UHSS) by way of friction stir welding (FSW). Steels are welded together to create tailor-welded blanks (TWB) for use in the automotive industry. Dual Phase (DP) 590, 780, and 980 steel as well as Transformation-Induced Plasticity (TRIP) 590 steel with thicknesses ranging from 1.2 mm to 1.8 mm were welded using friction stir welding under a variety of processing conditions, including experiments with dissimilar thicknesses. Samples were tested under tensile loads for initial determination if an acceptable weld had been created. Acceptable welds …

Comparación Técnico-Económica De Dos Edificios De Cuatro Pisos, Uno En Estructura Metálica Y Otro En Concreto Armado, Ronald Fernando Lopez Lopez, Diego Alexander Torres Vargas

Ingeniería Civil

No abstract provided.

Properties Of Light Transmitting Concrete, Dina Abdel Mohsen Abou Alia

Archived Theses and Dissertations

No abstract provided.

Development Of Knowledge Base Of Concrete Bridge Maintenance System, Bahre Karam

Masters Theses

Bridges are the key elements of any transportation system of a country. Bridges are expensive structures and therefore, it's essential to maintain and repair them on regular basis. Almost one third of the bridges in United States are reported to be in some what deteriorated conditions. This Research presents the development of knowledge base for decision support system for concrete bridges.

During this research various concrete bridge problems are investigated including COlTosion, delamination, cracks, spalling and scour etc. The inspection tools and techniques are addressed in order to identify these problems both for above and below water surface. The various …

Design Considerations For Reinforced Concrete Masonry Walls Regarding Moment Magnification, Jarred Wade Cowart

Masters Theses

Currently, regardless of the height of a reinforced masonry wall, engineers are required to consider moment magnification when using strength design provisions. An attempt at finding reasonable h/r limits for consideration of moment magnification is explored. Moment-curvature diagrams were developed using a spreadsheet to define the behavior of 8 inch and 12 inch concrete masonry walls. A series of models were created with axial load, out-of-plane load, height, reinforcing, and wall width as variables. The models were loaded out-of-plane in a finite element program until failure. The results were organized to produce the moment magnification of each wall. Results were …

Objective Test Methods For Waveguide Audio Synthesis, Steven Gregory Wood

Theses and Dissertations

Acoustic Physical Modeling has emerged as a newer musical synthesis technique. The most common form of physical modeling synthesis in both industry and academia is digital waveguide synthesis. Commercially available for the past thirteen years, the top synthesizer manufacturers have chosen to include physical modeling synthesis in their top of the line models. In the area of audio quality testing, the most common tests have traditionally been group listening tests. While these tests are subjective and can be expensive and time-consuming, the results are validated by the groups' proper quality standards. Research has been conducted to evaluate objective testing procedures …

Lifetime Testing Of Wire-Grid Polarizers With Selected Over-Coatings, Steven J. Malone

Theses and Dissertations

Wire-grid polarizers (WGPs) offer superior extinction, durability, angle of incidence, and heat resistance when compared to traditional organic polarizers. WGPs are found in applications such as high lumen lighting, laser devices, high lumen digital cinema projectors, LED packaging, and other integrated optical applications and are driving the need for over-coatings. Over-coating a WGP has been found to increase lifetime and durability. This research provides lifetime data on coated and uncoated WGPs. WGPs over-coated with 100nm of SiO2, 300nm of MgF2, and with no over-coating were heated to temperatures of 450 ºC, 500 ºC, and 550 ºC and timed until they …

Significant Trade Contractor Performance Characteristics As Evaluated By Big-D Construction, Conrad C. Johnson

Theses and Dissertations

The purpose of this research is to determine which aspects, other than price, of trade contractor performance are the most important to the general contractor, Big-D Construction. The impression a trade contractor leaves on the project manager and superintendent provides an indication of their performance. To determine what tasks trade contractors perform that most greatly impact overall perception of the general contractor's project manager and superintendent, hundreds of trade contractors were evaluated in ten separate categories and were then given an overall rating. The correlation between each category and the overall rating was found. The categories were then sorted from …

Rapid Runway Repair (Rrr): An Optimization For Minimum Operating Strip (Mos) Selection, David J. Duncan

Theses and Dissertations

Minimum Operating Strip (MOS) selection determines the exact placement of the MOS on the damaged runway, and therefore, the amount of munitions that need to be neutralized and the amount of damage that will need to be repaired. MOS selection, in essence, is the key determinant of the time required to attain an operational takeoff and recovery surface. Since the MOS selection stage determines the events and scope of work for all of the Rapid Runway Repair (RRR) stages that follow, it could be argued that this is the most important stage in the entire RRR process. The primary purpose …

A Qualitative Study Of Selected Quality Knowledge And Practices In Guangdong Province, China, Tyler R. Thomas

Theses and Dissertations

The manufacturing industry has become very competitive in today's global market environment. Many US companies are faced with the choice of keeping their manufacturing domestic or looking to low cost off-shore countries to take advantage of the labor costs differences. To gain an understanding of the state of manufacturing in China, a major focus in the manufacturing world today, this thesis was undertaken. This thesis presents the findings of research conducted in Guangdong Province, China in June - July, 2005. This research addressed customer focus, leadership and general manufacturing and quality knowledge and practices of small, medium and large sized …

Decision Analysis With Value Focused Thinking As A Methodology To Select Building For Deconstruction, Erika E. Maiorano

Theses and Dissertations

The purpose of this research was to examine the reuse and recycling of building materials on Wright-Patterson Air Force Base. There are a variety of conflicting factors concerning the removal of a building and the model quantitatively evaluates alternatives with respect to the decision maker’s values. The research questions were addressed with both a comprehensive literature review as well as the implementation of the value focused thinking methodology. The model found that the temporary living facilities are the alternatives that achieve the highest value. The result of this research effort was a value model that aids decision makers in identifying …

Evolución Histórica, Actualidad Y Tendencias De Explotación Del Espacio Subterráneo En Bogotá, Mayra Alexandra Rincón García, Lilián Andrea Riascos Navaja, Diego Alejandro Torres Niño

Ingeniería Civil

No abstract provided.

Spot Friction Welding Of Ultra High-Strength Automotive Sheet Steel, Jack H. Sederstrom

Theses and Dissertations

Spot friction welding (SFW) was performed on ultra high strength steel (UHSS) steel sheet commonly used in automobile manufacturing. Alloys studied included DP780, DP780EG, DP980, and DF140T sheet steel of varying thickness from 1.2 mm to 1.4 mm. Welding was accomplished using a PCBN standard tool. Weld strengths were then compared to a proposed AWS standard. Initial hardness readings were taken in cross sectioned samples. Grain structure in a SFW is presented. Resistance spot welds were created in three steels. This study focuses on the strength of SFW joints as compared to traditional resistance spot welding (RSW) in welding like …

A Value-Focused Thinking Model For The Selection Of The Best Rigid Pavement, Partial-Depth Spall Repair Material, Benjamin G. Speer

Theses and Dissertations

Concrete spalls on airfield pavements generate foreign object debris (FOD) that is damaging to aircraft engines, and may damage landing gear by roughening of the pavement surface. Repairing spalled concrete on aging and deteriorating airfields is essential for its safe operational use. Picking the best repair material from many products on the commercial market is difficult. There is wide variation on material properties, and good performance on certain criteria is critical to constructing long lasting repairs. Since there is currently no procedure for Air Force decision-makers to select the best rigid-pavement repair material, a model was created using Value-Focused Thinking …

A Decision Model For Selecting Energy Efficient Technologies For Low -Sloping Roof Tops Using Value-Focused Thinking, Michael J. Mccourt

Theses and Dissertations

The Air Force has a large inventory of low-sloping built up roofs (BURs) and millions of dollars are spent each year retrofitting these systems. The DOD has been directed to reduce non-renewable energy consumption by using energy-efficient technologies. These two details present a great opportunity to use the open roof space to install energy-efficient roofing technologies. The purpose of this research is to provide Air Force decision makers with a tool to assist them in deciding what roofing technologies should be installed on facilities. Value Focused-Thinking is the methodology used to construct the model, in which values were used, instead …

Using Neural Networks For The Diagnosis And Repair Of Corroded Steel In Reinforced Concrete Structures, Youssef Ibrahim Fayez

Archived Theses and Dissertations

No abstract provided.

Simulación Y Control De La Temperatura Dentro De Un Invernadero, Hernando Perez Rojas, Martín De Paul Cortes

Ingeniería en Automatización

El cambio de las condiciones atmosféricas durante los ciclos climáticos hace necesario utilizar invernaderos para proteger ciertos cultivos. Los invernaderos son estructuras cerradas en las que se mantienen microambientes que son adecuados para un buen desarrollo de las plantas. El control efectivo de algunas variables del clima dentro del invernadero es posible con la ayuda de modelos matemáticos. En este trabajo se presenta un modelo mejorado mediante una propuesta que incluye el efecto de la humedad sobre la temperatura dentro del invernadero. Esto puede considerarse como un avance en el diseño de modelos de clima de los invernaderos. Se presentan …

Definición Del Nivel De Servicio En El Túnel Vial Misael Pastrana Borrero, Michelle Paola Perez Palacios, Diana Maria Silva Manrique

Ingeniería Civil

No abstract provided.

Determinación Del Índice De Vulnerabilidad Sísmica En Viviendas De Interés Social De Uno Y Dos Pisos Construidas Con Mampostería Estructural En La Ciudad De Bogotá, Jorge Andres Navia Llorente, Elkin Mauricio Barrera Roa

Ingeniería Civil

No abstract provided.

Study Of Ranking Irregularities When Evaluating Alternatives By Using Some Electre Methods And A Proposed New Mcdm Method Based On Regret And Rejoicing, Xiaoting Wang

LSU Master's Theses

Multi-criteria decision-making (MCDM) is one of the most widely used decision methodologies in the sciences, business, and engineering worlds. MCDM methods aim at improving the quality of decisions by making the process more explicit, rational, and efficient. One intriguing problem is that oftentimes different methods may yield different answers to the same decision problem. Thus, the issue of evaluating the relative performance of different MCDM methods is raised. One evaluating procedure is to examine the stability of an MCDM method’s mathematical process by checking the validity of its proposed rankings. The ELECTRE II and III methods are two well-known MCDM …

Computer-Aided Weld Inspection By Fuzzy Modeling With Selected Features, Sean Najm Ghazavi

LSU Master's Theses

This thesis develops a computer-aided weld inspection methodology based on fuzzy modeling with selected features. The proposed methodology employs several filter feature selection methods for selecting input variables and then builds fuzzy models with the selected features. Our fuzzy modeling method is based on a fuzzy c-means (FCM) variant for the generation of fuzzy terms sets. The implemented FCM variant differs from the original FCM method in two aspects: (1) the two end terms take the maximum and minimum domain values as their centers, and (2) all fuzzy terms are forced to be convex. The optimal number of terms and …