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Full-Text Articles in Civil and Environmental Engineering

The Effect Of Flowable Fill On The Lateral Resistance Of Driven-Pile Foundations, Dustin David Miner Dec 2009

The Effect Of Flowable Fill On The Lateral Resistance Of Driven-Pile Foundations, Dustin David Miner

Theses and Dissertations

Flowable fill was used to strengthen the soft soil surrounding piles and behind the pile cap. The flowable fill placed beneath the pile cap surrounding the piles showed no appreciable increase in lateral resistance, this was partially due to the fact that the flowable fill placed had an unconfined compressive strength of 30 psi. Flowable fill was also used to replace a 12 ft wide, 6 ft thick, and 6 ft deep zone consisting of an average 475 psf clay that was adjacent to a 9-pile group in 3x3 pile configuration capped with a 9 ft x 9 ft x …

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Performance Of A Full-Scale Lateral Foundation With Fine And Coarse Gravel Backfills Subjected To Static, Cyclic, And Dynamic Lateral Loads, Joshua M. Pruett Nov 2009

Performance Of A Full-Scale Lateral Foundation With Fine And Coarse Gravel Backfills Subjected To Static, Cyclic, And Dynamic Lateral Loads, Joshua M. Pruett

Theses and Dissertations

Full-scale lateral load tests were performed on a pile cap with five backfill conditions: no backfill, densely compacted fine gravel, loosely compacted fine gravel, densely compacted coarse gravel, and loosely compacted coarse gravel. Static loads, applied by hydraulic load actuators, were followed by low-frequency, actuator-driven cyclic loads as well as higher frequency dynamic loads from an eccentric mass shaker. Passive resistance from the backfill significantly increased the lateral capacity of the pile cap. Densely compacted backfill materials contributed about 70% of the total system resistance, whereas loosely compacted backfill materials contributed about 40%. The mobilized passive resistance occurred at displacement-to-height …

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A Study Of Electricians' Preferences Of Pvc And Alternative Conduit Materials In The State Of Utah, Robert Andrus Nov 2009

A Study Of Electricians' Preferences Of Pvc And Alternative Conduit Materials In The State Of Utah, Robert Andrus

Theses and Dissertations

Polyvinyl Chloride, commonly known as PVC is a common and effective construction material. PVC is also one of the most common types of plastic. In 2008, global production and consumption of PVC was approximately 34.5 million tons. The construction industry is responsible for about 70% of the world's consumption of PVC. The largest construction use of PVC is for pipe and conduit. Modern construction, especially structures built for data services depend heavily upon PVC conduit for underground pathways to distribute electricity and data. PVC is also at the center of a fierce effort by environmental groups who would like to …

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Impact Of Large Gravity Loads On Buckling Restrained Braced Frame Performance, Mark Thurgood Matthews Nov 2009

Impact Of Large Gravity Loads On Buckling Restrained Braced Frame Performance, Mark Thurgood Matthews

Theses and Dissertations

The Buckling Restrained Braced Frame (BRBF) is used in steel structures as a lateral load resisting system for seismic events. In typical design procedure the impact of gravity loads acting on BRBFs is neglected and the beams and columns of the structure are designed to resist all gravity loads. In actuality BRBFs are supporting portions of gravity loads acting on the structure which may be changing the overall performance of BRBFs. The purpose of this study is to determine the impact of large gravity loads on BRBF performance. This is done using finite element analysis to test two different structures …

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An Improved Cube Cell Assembly For The Use With High Pressure/High Temperature Cubic Apparatus In Manufacturing Polycrystalline Diamond Compact Inserts, Kevin Christian Bach Nov 2009

An Improved Cube Cell Assembly For The Use With High Pressure/High Temperature Cubic Apparatus In Manufacturing Polycrystalline Diamond Compact Inserts, Kevin Christian Bach

Theses and Dissertations

The goal for this research was to reduce the current manufacturing cost of the polycrystalline diamond compact (PDC) inserts utilized in the natural gas and oil drilling industry while not reducing their current performance. Polycrystalline Diamond is added to the tungsten-carbide (WC) substrates commonly utilized in these applications because of its greater wear and thermal resistance. With the current cube cell design for the high-pressure/high-temperature apparatus, it is necessary to bond an extra WC substrate to the polycrystalline diamond insert to achieve the sizes generally ordered by the customers. The problem of bonding the extra WC substrate was solved by …

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Variability In Construction Of Cement-Treated Base Layers: Probabilistic Analysis Of Pavement Life Using Mechanistic-Empirical Approach, Tyler J. Rogers Nov 2009

Variability In Construction Of Cement-Treated Base Layers: Probabilistic Analysis Of Pavement Life Using Mechanistic-Empirical Approach, Tyler J. Rogers

Theses and Dissertations

The primary objective of this research was to quantify the improvement in service life of a flexible pavement constructed using full-depth reclamation (FDR) in conjunction with cement stabilization when specified reductions in the spatial variability of specific construction-related parameters are achieved. This study analyzed pavement data obtained through field and laboratory testing of a reconstruction project in northern Utah. Data analyses included multivariate regression, Monte Carlo simulation, and mechanistic-empirical analyses of a model pavement structure. The results of the research show a steadily increasing trend in 28-day unconfined compressive strength of the cement-treated base (CTB) layer with increasing reductions in …

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Automated Calibration Of The Gssha Watershed Model: A Look At Accuracy And Viability For Routine Hydrologic Modeling, Kayson M. Shurtz Nov 2009

Automated Calibration Of The Gssha Watershed Model: A Look At Accuracy And Viability For Routine Hydrologic Modeling, Kayson M. Shurtz

Theses and Dissertations

The goal of hydrologic models is to accurately predict a future event of a given magnitude. Historic data are often used to calibrate models to increase their ability to forecast accurately. The GSSHA model is a distributed model that uses physical parameters and physics based computations to compute water flow from cell to cell based on a 2 dimensional grid. The goal of calibration is to obtain good estimates for the actual parameters of the watershed. These parameters should then transfer to other storm events of different magnitudes more easily than an empirical model. In conducting this research three watersheds …

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Sensitivity Analysis And Calibration Of The Alligator Cracking Model In The Mechanistic-Empirical Pavement Design Guide Using Regional Data, Vivek Jha Oct 2009

Sensitivity Analysis And Calibration Of The Alligator Cracking Model In The Mechanistic-Empirical Pavement Design Guide Using Regional Data, Vivek Jha

Theses and Dissertations

The models used in the mechanistic-empirical pavement design guide (M-EPDG) were calibrated using the data from all across the United States. The alligator cracking model uses traffic, material and structural data along with local and global calibration factors to calculate the number of axles to failure and the damage index. Both of which are further used to calculate the fatigue cracking in the pavement with the help of regression coefficients and calibration constants. However, as these coefficients and constants were developed using the national database, the model might not predict the fatigue behavior of the pavement accurately for a particular …

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Analysis And Modeling Of Motor Vehicle Crashes Involving Air Force Military Personnel, Antonios Markopoulos Sep 2009

Analysis And Modeling Of Motor Vehicle Crashes Involving Air Force Military Personnel, Antonios Markopoulos

Theses and Dissertations

The primary purpose of this thesis was to improve the data analysis of Motor Vehicle Crashes (MVCs). This thesis employed the Air Force Safety Center (AFSC) data, collected over 20 years, of MVCs in which US Air Force (USAF) military personnel are involved when off duty and off base. Categorical Data Analysis and Analysis of Variance (ANOVA) were applied to identify risk factors related to MVCs and influence the severity of injuries and those factors associated with the alcohol consumption before driving, and affect the number of lost workdays resulting from MVCs. Categorical Data Analysis showed that male USAF members …

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Isogeometric Finite Element Analysis Using T-Splines, Jingang Li Aug 2009

Isogeometric Finite Element Analysis Using T-Splines, Jingang Li

Theses and Dissertations

Non-uniform rational B-splines (NURBS) methodology is presented, on which the isogeometric analysis is based. T-splines are also introduced as a surface design methodology, which are a generalization of NURBS and permit local refinement. Isogeometric analysis using NURBS and T-splines are applied separately to a structural mechanics problem. The results are compared with the closed-form solution. The desirable performance of isogeometric analysis using T-splines on engineering analysis is demonstrated.

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Analysis Of The Sediment Transport Capabilities Of Tuflow, Cameron G. Jenkins Aug 2009

Analysis Of The Sediment Transport Capabilities Of Tuflow, Cameron G. Jenkins

Theses and Dissertations

The need to know how river morphology changes due to sedimentation is increasingly important as we attempt to predict future events. Engineers use numeric models to predict effects of changed morphology on river systems. The numerical model Two-dimensional Unsteady Flow (TUFLOW) has recently added, and is continually improving, its capability to model sediment transport in rivers and coastal systems. This paper evaluates the new tools for modeling sediment transport presently contained within TUFLOW and compares these tools with analytical and laboratory case studies. Currently TUFLOW simulates combined bed and suspended load transport of noncohesive sediments under the effect of currents …

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Liquefaction Mitigation In Silty Sands Using Stone Columns With Wick Drains, Michael James Quimby Aug 2009

Liquefaction Mitigation In Silty Sands Using Stone Columns With Wick Drains, Michael James Quimby

Theses and Dissertations

Stone column treatment is commonly used to mitigate liquefaction hazard in sandy soils. Research and experience indicate that this method is effective for clean sands but that it may not be effective for silts and sands with fines contents greater than 15-20%. An alternative to the stone column method involves supplementing stone column treatment with pre-fabricated vertical wick drains installed prior to the stone columns installation. Although this method is used in practice, there has not been a formal academic study of its effectiveness. This thesis evaluates seven different case histories where wick drains were used and one where wick …

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Visualizing And Modeling Mining-Induced Surface Subsidence, Marcor Gibbons Platt Jul 2009

Visualizing And Modeling Mining-Induced Surface Subsidence, Marcor Gibbons Platt

Theses and Dissertations

Ground subsidence due to underground coal mining is a complex, narrowly-understood phenomenon. Due to the complicated physical processes involved and the lack of a complete knowledge of the characteristics of overlying strata, the reliability of current prediction techniques varies widely. Furthermore, the accuracy of any given prediction technique is largely dependent upon the accuracy of field measurements and surveys which provide input data for the technique. A valuable resource available for predicting and modeling subsidence is aerial survey technology. This technology produces yearly datasets with a high density of survey points. The following study introduces a method wherein these survey …

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Optimized Distribution Of Strength In Buckling-Restrained Brace Frames In Tall Buildings, Graham Thomas Oxborrow Jul 2009

Optimized Distribution Of Strength In Buckling-Restrained Brace Frames In Tall Buildings, Graham Thomas Oxborrow

Theses and Dissertations

Nonlinear time history analysis is increasingly being used in the design of tall steel structures, but member sizes still must be determined by a designer before an analysis can be performed. Often the distribution of story strength is still based on an assumed first mode response as determined from the Equivalent Lateral Force (ELF) procedure. For tall buckling restrained braced frames (BRBFs), two questions remain unanswered: what brace distribution will minimize total brace area, while satisfying story drift and ductility limits, and is the ELF procedure an effective approximation of that distribution? In order to investigate these issues, an optimization …

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Slip Lined Culvert Retrofit And Fish Passage, Joseph Ray Webb Jun 2009

Slip Lined Culvert Retrofit And Fish Passage, Joseph Ray Webb

Theses and Dissertations

Culverts throughout the country are approaching or are past their original design lives. These ‘baby boomer’ culverts will need to be repaired, rehabilitated, or replaced. Because entire culvert replacement is so expensive and intrusive, alternate measures to extend the culvert project life are growing increasingly popular. One such method is slip lining, where a ‘sleeve’ is installed within an existing culvert barrel and stabilized. Plastic pipe sleeves are very popular for slip lining primarily because the plastic material's lower Manning's roughness values allow for the culvert capacity to be maintained despite a reduction in culvert size. Unfortunately, the reduced friction …

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Automated All-Quadrilateral Mesh Adaptation Through Refinement And Coarsening, Bret D. Anderson Jun 2009

Automated All-Quadrilateral Mesh Adaptation Through Refinement And Coarsening, Bret D. Anderson

Theses and Dissertations

This thesis presents a new approach to conformal all-quadrilateral mesh adaptation. In finite element modeling applications, it is often desirable to modify the node density of the mesh; increasing the density in some parts of the mesh to provide more accurate results, while decreasing the density in other parts to reduce computation time. The desired node density is typically determined by a sizing function based on either the geometry of the model or the results of a finite element solution. Although there are numerous mesh adaptation methods currently in use, including initial adaptive mesh generation, node redistribution, and adaptive mesh …

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Economic Development Criteria And Project Prioritization, Jason Scott Mcgee May 2009

Economic Development Criteria And Project Prioritization, Jason Scott Mcgee

Theses and Dissertations

To provide a more in-depth analysis of potential roadway projects, the Utah Department of Transportation (UDOT) desired a method of evaluating projects according to their economic potential without using potentially costly computer models or excessive data collection. Brigham Young University (BYU) was retained to research and recommend criteria for the economic development criteria in the project-prioritization process. A literature review was first undertaken to better understand the transportation-economic development relationship. Using the literature review, combined with the information from the Economic Development Corporation of Utah, the Governor's Office of Planning and Budget, the Governor's Office of Economic Development, and a …

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Evaluation Of Full-Depth Reclamation On Strength And Durability Of Pavement Base Layers, Benjamin Earl Griggs Mar 2009

Evaluation Of Full-Depth Reclamation On Strength And Durability Of Pavement Base Layers, Benjamin Earl Griggs

Theses and Dissertations

The purpose of this research was to determine the effect of full-depth reclamation (FDR) on the strength and durability of aggregate base layers in a coordinated approach involving both field and laboratory testing. Field comparisons between the pre-reclamation neat base and post-reclamation blended base were supplemented with laboratory experiments conducted to determine the effects of reclaimed asphalt pavement (RAP) content, compaction effort, and heating on the strength and durability of roadways reconstructed using FDR with a portable asphalt recycling machine (PARM). Also, the effect of reclamation on the spatial uniformity of the pavement structures was explored by comparing variability in …

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Ground Source Heat Pumps Vs. Conventional Hvac: A Comparison Of Economic And Environmental Costs, Paul W. Fredin Mar 2009

Ground Source Heat Pumps Vs. Conventional Hvac: A Comparison Of Economic And Environmental Costs, Paul W. Fredin

Theses and Dissertations

The world is undergoing a dramatic transformation with regard to how it produces and consumes energy due to increasing demand from developing nations and diminishing new resource discoveries. In addition, there has been increased concern over the effect of carbon dioxide emissions on the environment. All of these issues have created a combined pressure to force the world to begin to redefine how energy is utilized. Geothermal or ground source heat pumps (GSHPs) may provide one potential solution to these problems. This research investigated vertical borehole closed-loop GSHP systems in direct comparison to natural gas furnaces combined with traditional air-conditioning …

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An Economic Analysis Of Military Family Housing: Should The Government Continue To Privatize?, Chad A. Woods Mar 2009

An Economic Analysis Of Military Family Housing: Should The Government Continue To Privatize?, Chad A. Woods

Theses and Dissertations

Providing military family housing has always been a difficult task for the United States government. To solve the latest housing short fall, the government signed the Military Housing Privatization Initiative (MHPI) into law in 1996. Under this program the government contracts private developers to build, own, and operate housing units. The developer then collects rent through housing allowance payments. At the time MHPI was signed into law, military members were expected to pay 15 percent of their housing costs out of pocket. Subsequent legislation has increased housing allowance to provide 100 percent of all housing costs eliminating out of pocket …

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The Utilization Of Light Gauge Steel In Residential Construction On The State Of Utah, Matthew Zaugg Perkins Mar 2009

The Utilization Of Light Gauge Steel In Residential Construction On The State Of Utah, Matthew Zaugg Perkins

Theses and Dissertations

This thesis researched why light gauge steel framing members are not used more in single-family residential construction. A survey was designed to extract information from licensed contractors in Utah on uses of light gauge steel framing members in residential homes. The purpose of the research was to discover what Utah builder's perception was concerning light gauge steel framing. Also, the researcher tried to learn a little about the contractors to see if there was a correlation between contractors that used light gauge steel and those that did not. Names of licensed general building contractors and residential contractors and their contact …

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Second-Order Structural Analysis With One Element Per Member, Jesse William Lyon Mar 2009

Second-Order Structural Analysis With One Element Per Member, Jesse William Lyon

Theses and Dissertations

In this thesis, formulas for the local tangent stiffness matrix of a plane frame member are derived by differentiating the member resistance vector in the displaced position. This approach facilitates an analysis using only one element per member. The formulas are checked by finite difference. The derivation leads to the familiar elastic and geometric stiffness matrices used by other authors plus an additional higher order geometric stiffness matrix. Contributions of each of the three sub-matrices to the tangent stiffness matrix are studied on both the member and structure levels through two numerical examples. These same examples are analyzed three different …

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Phosphorus Fractionation And Distribution Across Delta Of Deer Creek Reservoir, Warren C. Casbeer Mar 2009

Phosphorus Fractionation And Distribution Across Delta Of Deer Creek Reservoir, Warren C. Casbeer

Theses and Dissertations

Eutrophication of reservoir systems, which causes deterioration of water quality through increased algal growth, is detrimental to our sustainable water supply and additionally impairs other beneficial reservoir uses. Limiting the amount of phosphorus (P) entering the system has been the key management tool for this problem, as P is the main limiting nutrient for plant and algal growth. These efforts have focused on controlling input of P from point sources, such as effluents from wastewater treatment plants, dairies, and industrial factories. Even in systems (such as reservoirs) with significantly reduced external P loading, however, there has been continued eutrophication and …

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Behavior Of A Full-Scale Pile Cap With Loosely And Densely Compacted Clean Sand Backfill Under Cyclic And Dynamic Loadings, Colin Reuben Cummins Mar 2009

Behavior Of A Full-Scale Pile Cap With Loosely And Densely Compacted Clean Sand Backfill Under Cyclic And Dynamic Loadings, Colin Reuben Cummins

Theses and Dissertations

A series of lateral load tests were performed on a full-scale pile cap with three different backfill conditions, namely: with no backfill present, with densely compacted clean sand in place, and with loosely compacted clean sand in place. In addition to being displaced under a static loading, the pile cap was subjected to low frequency, small displacement loading cycles from load actuators and higher frequency, small displacement, dynamic loading cycles from an eccentric mass shaker. The passive earth pressure from the backfill was found to significantly increase the load capacity of the pile cap. At a displacement of about 46 …

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Correlating Responses Of Portable Field Instruments Used For Testing Aggregate And Soil Pavement Layers, Wendy Melissa Thompson Mar 2009

Correlating Responses Of Portable Field Instruments Used For Testing Aggregate And Soil Pavement Layers, Wendy Melissa Thompson

Theses and Dissertations

This research examined correlations among the responses of five portable aggregate and soil testing devices, including the nuclear density gauge (NDG), dynamic cone penetrometer (DCP), heavy Clegg impact soil tester (CIST), soil stiffness gauge (SSG), and portable falling-weight deflectometer (PFWD). Readings were analyzed from 41 project sites on treated and untreated base, subbase, and subgrade layers representing 15 different material types in Iowa, Louisiana, Utah, and Wyoming. Analyses of the data revealed statistically significant correlations for all six of the possible two-way comparisons involving the DCP, CIST, SSG, and PFWD, and a nomograph was developed for correlating responses among these …

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A Cost Assessment Of The Dayton Public Schools Vehicle Routing Problem, Frankie L. Woods Jr. Mar 2009

A Cost Assessment Of The Dayton Public Schools Vehicle Routing Problem, Frankie L. Woods Jr.

Theses and Dissertations

The routing and scheduling problem involves both constructing efficient routes to deliver goods or services to and from customers from a single depot or set of depots, as well as scheduling particular vehicles to these routes such that customers receive their goods within a specified time window. There have been several different methods developed to reduce the costs incurred in transporting goods or services (i.e. students) to customers (i.e. schools). This problem may be used to model many circumstances in logistics and public transportation. Several school districts do not utilize operations research techniques to minimize, as much as possible, the …

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An Analysis Of Construction Contractor Performance Evaluation System, Rebecca S. Brown Mar 2009

An Analysis Of Construction Contractor Performance Evaluation System, Rebecca S. Brown

Theses and Dissertations

A rigorous system for rating construction contractor performance does not exist for the USAF as identified by the Air Force Civil Engineer (USAF CE), Major General Del Eulberg (Eulberg, 2007). The United States Army Corp of Engineers (USACE) uses DD Form 2626 for contractor performance evaluation and contractor selection. The objective of this research is to strengthen the USAF contractor rating system by exploring USACE‘s use of DD Form 2626. Using data from DD Form 2626, statistical analysis was conducted to determine if the measured performance sub-items reflect their respective performance elements, whether the resulting performance elements relate to the …

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Ohio River Denial As A Transportation Corridor And Its Economic Impacts On The Energy Industry, Caglar Utku Guler Mar 2009

Ohio River Denial As A Transportation Corridor And Its Economic Impacts On The Energy Industry, Caglar Utku Guler

Theses and Dissertations

What if the Ohio River is disrupted or denied partially or completely as a transportation corridor? A disruption may be either a natural or man-made disaster or a planned outage on the river’s lock and dam structures. Recent history is full of water transport disruption events having significant economic effects on the waterside industries. To assess coal-based economic impacts, we developed a network flow model to represent waterside coal-fired power plants situated along the Ohio River, their respective coal supplying mines, and the various transportation modes that connect them. We show that significant transportation-centric insights can be derived by using …

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Stochastic Spatio-Temporal Uncertainty In Gis-Based Water Quality Modeling Of The Land Water Interface, Ahmad Mohamad Salah Feb 2009

Stochastic Spatio-Temporal Uncertainty In Gis-Based Water Quality Modeling Of The Land Water Interface, Ahmad Mohamad Salah

Theses and Dissertations

Integrated water resources management has been used for decades in various formats. The limited resources and the ever growing population keep imposing pressure on decision makers to better-, and reliably, manage the available waters. On the other hand, the continuous development in computing and modeling power has helped modelers and decision makers considerably. To use these models, assumptions have to be made to fill in the gaps of missing data and to approximate the current conditions. The type and amount of information available can also be used to help select the best model from the currently available models. Advances in …

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Assessing Water Quality Modeling In Subtropical Regions Based On A Case Study Of The Aguamilpa Reservoir, Oliver Obregon Dec 2008

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 …

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