Engineering Commons^™

College Of Engineering Senior Design Competition Fall 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Each student in his or her senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. The senior design project encourages the student to use everything learned in the engineering program to create a practical, real-world solution to an engineering challenge.

A highlight of the year-long senior design project is the senior design competition. This competition, which usually takes place the week before finals each semester, helps focus the senior students on increasing the quality and potential for commercial application for their design projects.

Judges from local industry evaluate the projects on innovation, commercial …

Seismic Evaluation Of Clark County Critical Bridges Using Nonlinear Static Procedures, Ahmad Said Saad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bridges are vital connective elements in community transportation systems. In the past, bridges have been severely damaged by earthquakes. However, with proper mitigation techniques, such as bridge retrofit, severe earthquake damage to bridges can be avoided. Since the 1970’s, design codes underwent major changes with regard to seismic analysis and design provisions of structures and bridges. Meanwhile, one third of the nation’s 600,000 inventoried highway bridges are considered as either structurally deficient or functionally obsolete.

This study is a part of the “Earthquakes in Southern Nevada” project. Earlier in this project, buildings and bridges in southern Nevada were studied in …

College Of Engineering Senior Design Competition Spring 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

Investigation Of Feasibility And Potential Mechanisms For The Bioregeneration Of Perchlorate Laden Gel-Type Anion Exchange Resin, Arjun Krishna Venkatesan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The feasibility and potential mechanisms for the bioregeneration of perchlorate laden gel-type anion exchange resin were investigated in this study. Bioregeneration is a sustainable process when compared to one time use of resin and disposal by incineration. Batch and bench-scale bioregeneration experiments were performed to evaluate the feasibility of the process and to gain insight into potential mechanisms that control gel-type resin bioregeneration. The results of the bioregeneration tests suggested that the initial phase of the bioregeneration process is controlled by kinetics, while the later phase is controlled by diffusion. Higher perchlorate load in the resin had a positive effect …

The Influence Of Carbon Source Types And Nitrate On The Performance Of The Enhanced Biological Phosphorus Removal Systems, Shamim Ara Begum

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focuses on two issues in enhanced biological phosphorus removal (EBPR). The first issue encompasses the effect of the type of carbon sources (i.e. volatile fatty acids and non volatile fatty acids) on the microbiology of EBPR. The second issue deals with the influence of denitrification on EBPR. Few studies have been performed to investigate these two issues. The recent findings on these areas are summarized below to establish the knowledge gaps this dissertation attempted to address. Details on the specific findings can be found in the literature review portion of this proposal.

Using Oceanic-Atmospheric Oscillations For Long Lead Time Streamflow Forecasting, Ajay Kalra, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

We present a data-driven model, Support Vector Machine (SVM), for long lead time streamflow forecasting using oceanic-atmospheric oscillations. The SVM is based on statistical learning theory that uses a hypothesis space of linear functions based on Kernel approach and has been used to predict a quantity forward in time on the basis of training from past data. The strength of SVM lies in minimizing the empirical classification error and maximizing the geometric margin by solving inverse problem. The SVM model is applied to three gages, i.e., Cisco, Green River, and Lees Ferry in the Upper Colorado River Basin in the …

Role Of Forward Model In Surface-Wave Studies To Delineate A Buried High-Velocity Layer, Xiaohui Jin, Barbara Luke, Carlos Calderon-Macias

Civil and Environmental Engineering and Construction Faculty Research

Procedures are tested and compared for processing Rayleigh surface wave data to obtain one-dimensional shear wave velocity profiles for a hypothetical site that contains a buried high-velocity layer (HVL). The main purpose of such an investigation would be to discriminate and characterize the HVL. When target dispersion curves are derived from synthetic time histories, for the most part, the HVL is better identified when profiles are inverted using only the fundamental mode of Rayleigh wave propagation, rather than a more compatible but more complex forward model. The outcomes imply that in practice, a simple forward model might be more successful …

An H-Adaptive Finite-Element Technique For Constructing 3d Wind Fields, Darrell Pepper, Xiuling Wang

Mechanical Engineering Faculty Research

An h-adaptive, mass-consistent finite-element model (FEM) has been developed for constructing 3D wind fields over irregular terrain utilizing sparse meteorological tower data. The element size in the computational domain is dynamically controlled by an a posteriori error estimator based on the L2 norm. In the h-adaptive FEM algorithm, large element sizes are typically associated with smooth flow regions and small errors; small element sizes are attributed to fast-changing flow regions and large errors. The adaptive procedure employed in this model uses mesh refinement–unrefinement to satisfy error criteria. Results are presented for wind fields using sparse data obtained from two regions …

Damage Characterization Of Beam-Column Joints Reinforced With Gfrp Under Reversed Cyclic Loading, Aly M. Said

Civil and Environmental Engineering and Construction Faculty Research

The use of fiber reinforced polymer (FRP) reinforcement in concrete structures has been on the rise due to its advantages over conventional steel reinforcement such as corrosion. Reinforcing steel corrosion has been the primary cause of deterioration of reinforced concrete (RC) structures, resulting in tremendous annual repair costs. One application of FRP reinforcement to be further explored is its use in RC frames. Nonetheless, due to FRP's inherently elastic behavior, FRP-reinforced (FRP-RC) members exhibit low ductility and energy dissipation as well as different damage mechanisms. Furthermore, current design standards for FRP-RC structures do not address seismic design in which the …

Interpreting Surface-Wave Data For A Site With Shallow Bedrock, Daniel W. Casto, Barbara Luke, Carlos Calderon-Macias, Ronald Kaufmann

Civil and Environmental Engineering and Construction Faculty Research

The inversion of dispersive Rayleigh-wave data has been shown to be successful in providing reliable estimated shear-wave velocities within unconsolidated materials in the near surface. However, in a case where the multi-channel analysis of surface waves method was applied to a site consisting of clay residuum overlying basalt bedrock, inversion for the fundamental-mode Rayleigh wave resulted in shear-wave velocities within the rock that are less than half of expected values. Forward modeling reveals that the fundamental-mode dispersion curve is hardly sensitive to bedrock velocity perturbations over a practical range of wavelengths, leading to poorly constrained solutions. Standard surface-wave methods can …

Quantity-Based Cost Forecasting System For Street Construction Projects, Nipesh Pradhananga

UNLV Theses, Dissertations, Professional Papers, and Capstones

Construction projects typically are not withdrawn after going into the competitive bidding process. The decision of contracting authorities regarding which projects will proceed to the bidding stage depends, in part, upon the early estimates of probable cost. Efforts are made to make this estimate as realistic as possible. Irrespective of the estimate of probable cost, the actual project cost is established by the amount of the winning bid.

This study analyzed historical bid data of street construction projects undertaken by the Public Works Department, Clark County, Nevada, from 1991 through 2006. The focus of this study was on utilizing statistical …

Tensile Strength And Failure Criterion Of Analog Lithophysal Rock, James A. Nott

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project determines the tensile strength of lithophysal analog rock and presents failure criteria that can be used by geotechnical engineers to evaluate underground structures in rock. The physical and mechanical properties that are related to the failure criterion, such as porosity, compressive strength and modulus of elasticity, are also discussed. Experimental tensile tests were made using direct uniaxial and indirect Brazilian tests. Three 4-inch specimens were fabricated and tested in direct uniaxial tensile tests using Hydro-Stone TB. The results showed that the elastic tensile modulus of elasticity was within two percent of existing data for the compressive modulus of …

Soil Moisture And Water Stage Estimation Using Precipitation Radar, Sumit Puri

UNLV Theses, Dissertations, Professional Papers, and Capstones

In south-western United States, soil moisture data is important for drought studies in the region which is experiencing a drought for many years, whereas in South Florida, water stage data is required by hydrologists to monitor the hydrological flow in wetlands. Soil moisture data and water stage data are not sufficiently available due to sparse monitoring stations. Installation of dense measuring stations over an extended area is costly and labor intensive. Therefore, there is a need to develop an alternative method of measuring soil moisture and water stage. Microwave remote sensing has proven to be a useful tool in the …

Mitigation Of Impact Vibrations Using Impedance Mismatch In Cylindrical Structures, Sachiko Sueki

UNLV Theses, Dissertations, Professional Papers, and Capstones

The focus of this work is to study the phenomenon of material impedance mismatch to determine its effect on the mitigation of high frequency accelerations in projectile and long bar structures within linear ranges of materials. In this study, the acceleration responses of structures with various materials and material combinations were studied experimentally, numerically and by the Finite Element Analysis (FEA). Air-gun tests conducted by the US Army Research Laboratory were modeled using FEA to simulate the acceleration pulse and shock waves experienced by artillery components during a launch. After the prototype of projectile was selected, further studies were conducted …

Parametric Study Of Stimulus-Response Behavior Incorporating Vehicle Heterogeneity In Car-Following Models, Saidi Siuhi

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this study was to develop a family of car-following models that address the shortcomings of car-following models developed by General Motors (GM) in the 1950s. The developed models consist of separate models for acceleration, deceleration, and steady-state responses for congested freeway traffic conditions. The study calibrated the models using individual vehicle trajectory data collected on a segment of Interstate 101 in Los Angeles, California. Furthermore, the study validated the models using individual vehicle trajectory data collected on a segment of Interstate 80 in Emeryville, California. The study used nonlinear regression with robust standard errors to estimate the …

Analysis Of A Caliche Stiffened Pile Foundation, Richard C. Stone Jr.

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cemented carbonate deposits (known locally as "caliche") in Las Vegas have been used to support shallow and deep foundations with relatively high bearing pressures compared to soil. Most high rise structures in Las Vegas are founded on either a large mat or a long pile foundation. Recently, a new foundation type consisting of a short pile system bonded to shallow cemented layers was utilized for a large high rise building in Las Vegas and settlements during construction were recorded. The bonding of caliche layers together with short piles forms a caliche stiffened pile (CSP) foundation. The CSP foundation is unique …