Engineering Commons^™

Evaluación Probabilística De La Amenaza Sísmica Regional Para Tunja, Gladys Patricia Molina Molina

Ingeniería Civil

El presente trabajo contiene la evaluación probabilística de la amenaza sísmica para la Ciudad de Tunja, que está ubicada en la cordillera Oriental colombiana a los 05º32’07” de latitud Norte y 73º22’04” de longitud oeste. Tunja se encuentra en un área propensa a la actividad sísmica; en la zona se desarrollan varios sistemas de fallas activas. Según datos históricos, en los últimos 500 años la sismicidad de Tunja y su área cercana ha sido destacada. Esta investigación se desarrolló siguiendo los procedimientos de Hanks y Cornell (1994) que permite estimar las aceleraciones pico esperadas para periodos de retorno de 475, …

Assessing Water Quality Modeling In Subtropical Regions Based On A Case Study Of The Aguamilpa Reservoir, Oliver Obregon

Theses and Dissertations

The shortage of water in Mexico has made public and private institutions look at reservoirs as an alternative solution for present and future water supply. However, eighty percent of the existing reservoirs in Mexico are contaminated at some level, many severely. Water quality models are water-management tools used to diagnose water quality problems and the impact of various environmental conditions. They can be effective in assessing various measures of remediation leading to improved water quality. In most of the cases such water quality models have been successfully applied in reservoirs located in temperate climates. However, the use of water quality …

Análisis De La Influencia Del Refuerzo Transversal En El Confinamiento De Columnas De Sección Circular Y Rectangular Modeladas A Escala Reducida, Jhony Armando Sanchez Sierra

Ingeniería Civil

No abstract provided.

P-M Characteristics Of Reinforced Concrete Sections, Paul Johnson

All Theses

This manuscript presents two parametric studies which were performed to evaluate a provision which originated in the 1994 Uniform Building Code (UBC). This provision states that if gravity-induced axial loads carried by a reinforced concrete member are greater than 35% of the pure axial load-carrying capacity (Po) of that member, then the member cannot be used as part of the lateral force resisting system (LRFS). Along with the UBC provision, the Structural Engineers Association of California's (SEAOC) Blue Book states that the value of 0.35Po corresponds to the level of axial load representing a balanced state of strain, i.e., the …

Investigation Of The Merging Of Two Axisymmetric Turbulent Jets, Jeffrey Smith

All Theses

A study was done to determine the converging distance of two axisymmetric turbulent jets and to compare the experimental results with the Reichardt hypothesis. This experiment consisted of measuring the velocity profiles of the two jets and manipulating the momentum ratio between the jets. Through testing, it was determined that the Reichardt hypothesis while efficient, over predicts the converging distance of the jets by up to 25% in some cases.
An Acoustic Doppler Velocimeter (ADV) was used to take measurements across the path of the jets and monitored the velocity and the turbulent kinetic energy. After observing the velocity profiles, …

Analysis Of Speed-Related Crashes Using Event Data Recorder Data, Swathi Korpu

All Theses

Safety in general is defined as 'the absence of unintended harm to living creatures or inanimate objects' (Evans, 2004). Traffic safety is measured in terms of motor vehicle crashes. A crash is an unplanned event which results in either fatality, or injury or property damage. Of all the factors that contribute to a crash, speed is a major issue, as more than 31 percent of all fatal crashes involve speeding (NHTSA, 2007). The speed-safety relationship can be determined by knowing the effect of speed on the frequency and severity of crashes. The relationship between speed and frequency of crashes is …

Dechlorinating And Iron Reducing Bacteria Distribution In A Trichloroethene Contaminated Aquifer, Carmen Lourdes Yupanqui Zaa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Operable Unit 5 (OU 5) area of Hill Air Force Base currently has two trichloroethene-contaminated groundwater plumes underneath residential areas in Sunset and Clinton, Utah. Bioremediation by biological reductive dechlorination can be an important mechanism for the removal of chlorinated compounds from the plumes. The presence of suitable bacteria to carry on reductive dechlorination is the key in the bioremediation process. The goal of this study was to determine the distribution and population density of the 16S rRNA genes of Bacteria, Dehalococcoides ethenogenes, Desulfuromonas michiganensis, Geobacter spp and Rhodoferax ferrireducens-like bacteria, as well as the functional genes trichloroethene reductive …

Integrating Surface And Sub Surface Flow Models Of Different Spatial And Temporal Scales Using Potential Coupling Interfaces, Alphonce Chenjerayi Guzha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of this research was to develop and utilize a coupled surface water groundwater model to simulate hydrological responses of watersheds. This was achieved by coupling the U.S. Geological Survey (USGS) groundwater flow model, MODFLOW, and the rainfall runoff model, TOPMODEL, in one case study and coupling MODFLOW with a networked version of TOPMODEL called TOPNET in another case study. The model coupling was achieved using the InCouple approach, which utilizes Potential Coupling Interfaces (PCIs) that are abstractions from model flow diagrams that expose only those aspects of a model relevant to coupling. Coupling the rainfall-runoff models to …

The Effect Of Climate Change On The Hydrology Of A Mountainous Catchment In The Western United States: A Case Study At Reynolds Creek, Idaho, Anurag Nayak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research is focused on understanding the sensitivity of a hydrologic regime at the Reynolds Creek Experimental Watershed (RCEW), a snowmelt dominated semi-arid mountain basin located in southwest Idaho, to climate warming.

Climate data, collected during 1962 to 2006 at many locations in the RCEW, was carefully checked, preprocessed, and corrected for errors and noise signals introduced by the instrument malfunctioning and extreme weather conditions. An Automated Precipitation Correction Program (APCP) was developed to remove mechanical errors from the weighing-recording bucket type precipitation gauge measurements. APCP produces comparable results to the manual techniques but a degree faster (few minutes against …

Rank-Data Distribution Method (R-D Method) For Daily Time-Series Bayesian Networks And Total Maximum Daily Load Estimation, Joon-Hee Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Daily time series-based models are required to estimate the higher frequency fluctuations of nutrient loads and concentrations. Some mechanistic mathematical models can provide daily time series outputs of nutrient concentrations but it is difficult to incorporate non-numerical data, such as management scenarios, to mechanistic mathematical models. Bayesian networks (BNs) were designed to accept and process inputs of varied types of both numerical and non-numerical inputs.

A Rank-Data distribution method (R-D method) was developed to provide large time series of daily predicted flows and Total Phosphorus (TP) loads to BNs driving daily time series estimates of T-P concentrations into Hyrum and …

Estimating Total Phosphorus And Total Suspended Solids Loads From High Frequency Data, Amber Spackman Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Frequently measured turbidity was examined as a surrogate for total phosphorus (TP) and total suspended solids (TSS) loads at two locations in the Little Bear River, Utah, USA. Using regression techniques, equations were developed for TP and TSS as functions of turbidity. The equations accounted for censored data, and additional explanatory variables to represent hydrological conditions were considered for inclusion in the equations. By using the resulting surrogate relationships with high frequency turbidity measurements, high frequency estimates of TP and TSS concentrations were calculated. To examine the effect of sampling frequency, reference loads were determined from the concentration records for …

Hydrogen Production By Anaerobic Fermentation Using Agricultural And Food Processing Wastes Utilizing A Two-Stage Digestion System, Reese S. Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hydrogen production by means of anaerobic fermentation was researched utilizing three different substrates. Synthetic wastewater, dairy manure, and cheese whey were combined together at different concentrations under batch anaerobic conditions to determine the optimal hydrogen producing potential and waste treatment of each. Cheese whey at a concentration of 55% was combined with dairy manure at a concentration of 45% to produce 1.53 liters of hydrogen per liter of substrate. These results are significant because the control, synthetic wastewater, which was a glucose-based substrate, produced less hydrogen, 1.34 liters per liter of substrate, than the mixture of cheese whey and dairy …

Development Of A Mathematical Model For 3d Reconstruction Of Target Objects By Photogrammetry, Keith F. Blonquist

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis outlines the development of a mathematical model which can be used to perform 3D reconstruction of a target object from surveillance images. 3D reconstruction is a common procedure in photogrammetry, but performing 3D reconstruction from surveillance images can be more difficult than typical photogrammetry applications.

Surveillance images are generally captured in an unsystematic manner because there is no control over the target that is being photographed. Surveillance images can have a wide variety of fields of view, are often captured with uncalibrated cameras, and typically the targets are objects for which there is no other a priori information. …

Evaluation Of Arrayed-Field Concentration Measurements And U. S. Epa-Regulatory Models For The Determination Of Mixed-Source Particulate Matter Emissions, Derek Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With the continued population growth and the blurring of the urban and rural interface, air quality impacts associated with agricultural particle-producing processes are becoming increasingly important. There is a lack of emission rate data from these source types and no prescribed measurement technique available to the agricultural and regulatory communities. One technique that has shown promise is combining field measurements with inverse modeling. This approach was used herein to examine particulate emissions from an almond harvesting operation, a cotton ginning facility, and comparative emissions from conservation versus conventional tillage practices. EPAapproved models ISCST3 and AERMOD were used with AirMetrics samplers. …

Uptake And Release Kinetics Of Sulfolane By Cattail Plants, Tiffany Leo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sulfolane (tetrahydrothiophene 1,1-dioxide, C₄H₈O₂S) is a highly water-soluble, non-ionizable, organic compound used along with diisopropanolamine in the Sulfinol™️ process to remove hydrogen sulfide from natural gas. Sulfolane has been identified in wetland vegetation near a sour gas processing facility in Alberta, Canada, and extensive uptake of sulfolane by cattails has also been demonstrated in a laboratory environment. Consequently, it has been suggested that plants could play an important role in the natural attenuation of sulfolane in contaminated wetlands. This assumes that the sulfolane is metabolized and/or sequestered in the plant and not released back …

Air Demand In Free Flowing Gated Conduits, David Peter Oveson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A physical experimental setup of a circular, gated closed conduit was built at the Utah Water Research Laboratory (UWRL). Setup configurations were modified and data were measured to aid in the study of physical variables on air demand. It was determined that gate opening, gate and water surface roughness, and conduit length all were significant variables on the air demand measured through the conduit air vent. It was also determined that no noticeable air velocity profile existed above the air-water interface. A linear relationship was found between the air flow rate to water flow rate ratio (air-demand ratio) and head-to-gate …

Identification Of Chlorinated Solvent Sources In The Indoor Air Of Private Residences Around Hill Air Force Base, Utah, Andrew Jensen Hall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Volatile chlorinated solvents such as trichloroethylene (TCE), 1,2 dichloroethane (1,2 DCA), and perchloroethylene (PCE) have been identified in the indoor air of residences located near Hill Air Force Base (AFB), Utah. These vapors can originate from either volatilization of contaminates from shallow contaminated groundwater and transport into residences or from sources within the residence. The focus of the thesis was the development of a testing strategy for determining sources of TCE, 1,2 DCA, and PCE in the indoor air of residences near Hill AFB.

Eight residences were selected for this study by Hill AFB based on prior detections of TCE, …

Generalized Event Tree Algorithm And Software For Dam Safety Risk Analysis, Anurag Srivastava

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Event tree analysis is a most commonly used method in dam safety risk analysis modeling. Available software tools for performing event tree analyses lack the flexibility to efficiently address many important factors in dam safety risk analysis. As a result of these practical limitations, spreadsheets have been used, sometimes including Visual Basic macros, to perform these analyses. However, this approach lacks generality and can require significant effort to apply to a specific dam or to modify the event tree structure. In response to these limitations, here a generalized event tree analysis tool, DAMRAE (DAM safety Risk Analysis Engine), has been …

Volatilization Of Trichloroethylene From Shallow Subsurface Environments: Trees And Soil, Rachel Melanie Winters

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Results from two previous studies conducted at Operable Unit 2 (OU2) of Hill Air Force Base, Utah indicate that the phytovolatilization (volatilization from leaves and trunk) of TCE by indigenous trees as well as soil surface flux may play a significant role in the removal of TCE from shallow groundwater plumes around the base. Previous studies investigated late summer and early autumn TCE leaf volatilization but no attempt was made to examine potential TCE volatilization seasonal variability and the volatilization of TCE directly from tree trunks. Whole tree transpiration rates were also not directly measured. To address those limitations and …

Measuring And Modeling Of Plant Root Uptake Of Organic Chemicals, Erik Dettenmaier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Determining the root uptake of xenobiotic organic chemicals into plants is critical for assessing the human and ecological health risks associated with the consumption of plants growing in contaminated environments. Root uptake of xenobiotic organics occurs passively in conjunction with transpiration and the transport from root to shoot is ultimately controlled by passage through one or more lipid root membranes. The transpiration stream concentration factor (TSCF), the ratio between the concentration of a chemical in the xylem to that in the solution used by the roots, is used to describe the relative ability of an organic chemical to be passively …

The Influence Of Debris Cages On Critical Submergence Of Vertical Intakes In Reservoirs, Skyler D. Allen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study quantifies the influence of debris cages on critical submergence at vertical intakes in reservoir configurations. Four model debris cages were constructed of light panel material. A vertical intake protruding one pipe diameter above the floor of a model reservoir was tested in six configurations: open intake pipe, a debris grate placed directly over the intake pipe, and debris cages representing widths of 1.5*d and 2*d and heights of 1.5*c and 2*c, where d is diameter of the intake and c is height of intake above reservoir floor. A selection of top grating configurations and a submerged raft configuration …

Optimal Maintenance Crew Composition And Enhancement Of Crew Productivity, Robert Schober

All Theses

The South Carolina Department of Transportation (SCDOT) dedicates a large portion of its budget and other resources to the maintenance of the State's transportation infrastructure. In order to maximize the efficiency and productivity of the State's highway maintenance workforce, the SCDOT partnered with Clemson University to research the performance of these maintenance crews. The goal of this research is to identify optimal crew compositions, if possible, and to suggest potential crew productivity enhancement methods.
Data was collected from the SCDOT Highway Maintenance Management System (HMMS) and crew rankings were developed based on several pre-determined performance criteria. These rankings were then …

Experimental And Modeling Studies For Optimizing Flocculant-Aided Sediment Retention Ponds, Byung Joon Lee

All Dissertations

Attempts to control sediment-containing runoff and associated water quality problems have involved the establishment of many small to medium sediment retention ponds and the injection of nonionic and anionic polyacrylamide (PAM) flocculants to enhance colloid removal. However, to date use has been driven more by practicing engineers and trial-and-error approaches than by logical and consistent design approaches. Therefore, the purpose of this research was to optimize colloidal clay removal in PAM-aided sediment retention ponds by applying experimental and theoretical methodologies.
Initially, simple measurement techniques for the molecular weight (MW) and charge density (CD) of various PAMs were tested and their …

Theoretical Determination Of Subcritical Sequent Depths For Complete And Incomplete Hydraulic Jumps In Closed Conduits Of Any Shape, Nathan John Lowe

Theses and Dissertations

In order to predict hydraulic jump characteristics for channel design, the jump height may be determined by calculating the subcritical sequent depth from momentum theory. In closed conduits, however, outlet submergence may fill the conduit entirely before the expected sequent depth is reached. This is called an incomplete or pressure jump (as opposed to a complete or free-surface jump), because pressure flow conditions prevail downstream. Since the momentum equation involves terms for the top width, area, and centroid of flow, the subcritical sequent depth is a function of the conduit shape in addition to the upstream depth and Froude number. …

Application Of Structural Control For Civil Engineering Structures, Abdollah Shafieezadeh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study presents the application of control methods in seismic mitigation of structural responses. The study consists of two parts. In the first section, fractional order filters are utilized to enhance the performance of the conventional LQR method for optimal robust control of a simple civil structure. The introduced filters modify the state variables fed back to the constant gain controller. Four combinations of fractional order filter and LQR are considered and optimized based on a new performance criterion defined in the paper. Introducing fractional order filters is shown to improve the results considerably for both the artificially generated ground …

Analysis Of Effectiveness Of Bridges With Partial Isolation, Wenying Hu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A special class of seismically isolated bridges shares a common feature in that both ends of the superstructure are restrained and isolators over the columns of bridge uncouple the superstructure from the ground motions. They are defined as partial isolation bridges. From measured acceleration responses, effectiveness of full seismic isolation had been confirmed widely. However, the seismic isolation behavior in the partial isolation has not been widely observed.

The effectiveness of partial isolation is evaluated in this study. The static design procedures for linear and nonlinear partially isolated bridges are developed. Results from the static analysis of linear and nonlinear …

Simulating Truck Lane Management Approaches To Improve Efficiency And Safety Of Highways In Knoxville, Tennessee, Adebola Adebisi Adelakum

Masters Theses

Increased globalization has caused large increases in truck traffic on the nation’s interstate system, with much additional growth expected in the coming years. This growth has elevated interest in developing new strategies to address rising levels of truck traffic, especially in dense and congested urban areas. This thesis focuses on the evaluation of several alternative lane management configurations as they compare to the current lane configuration in search of the best fit for operational improvement. This task was performed in two ways – survey and simulation. A survey of 500 long-haul truck drivers was administered in Knoxville, Tennessee, at the …

New Consolidation Of Emission And Processing For Air Quality Modeling Assessment In Asia, Yuan Du

Masters Theses

Gridded Asian emission input with fine resolutions for regional photochemical air quality modeling is absent from current studies. A new top-down emission process based on GIS-FORTRAN program has been developed in this study to consolidate the current available regional emissions in Asia and provide model-ready emission input with more flexibility. The INTEX-B anthropogenic emission inventory in 2006 integrated with biogenic from GEIA, as well as biomass burning and ship emissions from TRACE-P has been adopted as the top-level emissions, which are then spatially allocated into grid-cell level by our GIS application. The spatial allocation factors generated for this process are …

Bioflocculation For Control Of Wastewater Pond Microalgae, Daniel Thomas Frost

Master's Theses

Investigates several hypotheses regarding the use of bioflocculation as a harvesting method for wastewater pond microalgae. Research performed on pilot-scale high rate ponds (HRPs) on the California Central Coast.

Crashes In The Vicinity Of Major Crossroads, Charles G. Allen

Theses and Dissertations

Major crossroads are designed to facilitate the conflicting movements of numerous vehicles in a manner that is both safe and efficient. Accesses located within the functional areas of major crossroads add complication to intersection activity due to additional conflicts arising from ingressing and egressing movements at the accesses. In this research, the impact of accesses on crashes within major crossroad functional areas was analyzed. Specifically, the effects of access spacing within functional areas and access setback from intersections were addressed. In order to conduct the analysis, the functional areas of 159 signalized major arterial crossroads across the state of Utah …