Browsing Civil & Environmental Engineering by Issue Date
Now showing items 21-40 of 103
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Influence of Molecular Interactions on Elastic Properties and Oxygen Diffusion in PolyButylene Terephthalate Polymer: A Molecular Dynamics Study
(North Dakota State University, 2012)In most barrier applications, both mechanical and diffusion properties of the material are important. In this thesis the evaluation of molecular mechanisms responsible for the enhanced elastic properties of Polymer Clay ... -
In Situ Groundwater Remediation using Enricher Reactor-Permeable Reactive Biobarrier
(North Dakota State University, 2012)Permeable reactive biobarrier (PRBB) is a flow-through zone where microorganisms degrade contaminants in groundwater. Discontinuous presence of contaminants in groundwater causes performance loss of a PRBB in removing the ... -
Alginate Encapsulated Nanoparticle-Microorganism System for Trichloroethylene Remediation
(North Dakota State University, 2012)Nanoscale zero-valent iron (NZVI) particles were encapsulated in calcium alginate capsules for application in environmental remediation. TCE degradation rates for encapsulated and bare NZVI were similar indicating no adverse ... -
Initial Swelling Mechanism of Expansive Clays: A Molecular Dynamics Study
(North Dakota State University, 2012)Expansive soils are widely found in many parts of the world. Highly active smectite clay mineral Montmorillonite is the major constituent in these clays and can expand or contract up to 15 times of their original volume. ... -
Functionality of a Damaged Steel Truss Bridge Strengthened with Post-Tensioned CFRP Tendons
(North Dakota State University, 2012)This research program investigates the performance of a steel truss bridge when subjected to both localized web damage and a subsequent post-tensioned strengthening approach. The investigation utilizes a combined approach ... -
A Comparative Study of Nitrification in Fargo and Moorhead Distribution Networks
(North Dakota State University, 2012)Nitrification in water distribution networks has become a growing concern for water supplies in the United States. The use of chloramines as a disinfectant in distribution pipe networks has become increasingly popular to ... -
Identifying Causes of Dissolved Oxygen Depletion and Determination of Sediment Oxygen Demand in the Souris River
(North Dakota State University, 2013)The Upper Souris River was placed on the Environmental Protection Agencies (EPA) impaired waters list for low dissolved oxygen (DO). A Total Maximum Daily Load (TMDL) study was conducted to determine possible causes of DO ... -
An Anisotropic Damage Mechanics Model for Concrete with Applications for Fatigue Loading and Freeze-Thaw Effects
(North Dakota State University, 2013)It is well known that the formation and propagation of microcracks within concrete is anisotropic in nature, and has a degrading effect on its mechanical performance. In this thesis an anisotropic damage mechanics model ... -
An Investigation into Bromate Formation in Ozone Disinfection Systems
(North Dakota State University, 2013)Ozonation is used as an alternative disinfection process to chlorination but unfortunately has a potential of oxidizing bromide, a natural component of water sources, to bromate. Bromate is a possible carcinogen with a ... -
Modeling of Surface Microtopography and its Impacts on Hydrologic Processes
(North Dakota State University, 2014)Understanding the impacts of surface microtopography on hydrologic processes is critical. The objectives of this thesis research are: (1) to evaluate the effects of DEM resolution on microtopographic characteristics, ... -
Modeling of Temperature Impacts on Fixed Film Microbial Growth and Nitrification Kinetics
(North Dakota State University, 2014)Monod-type kinetic models, used in simulating microbial growth in biological treatment systems, suggest significant decreases of substrate utilization at lower temperatures. However, it is documented that performance of ... -
Investigating Biodegradability of Dissolved Organic Nitrogen in Oligotrophic and Eutrophic Systems
(North Dakota State University, 2014)Dissolved organic nitrogen (DON) in water and wastewater is a major public concern. In drinking water treatment plants (WTP), DON and biodegradable DON (BDON) may form carcinogenic by-products during disinfection and might ... -
Crack-Dependent Response of Structural Steel Members Repaired with CFRP
(North Dakota State University, 2014)Cracking of the lower flange in steel-girder bridges is a critical consideration because it will influence flexural behavior such as load-carrying capacity. Timely rehabilitation will save long-term repair costs and warrant ... -
Energy-Saving Non-Metallic Connectors for Precast Sandwich Wall Systems in Cold Regions
(North Dakota State University, 2014)Conserving energy in large structural buildings has become very important in today's economy. A number of buildings today are constructed with sandwich wall panels. Steel connections are most commonly used in these panels. ... -
Development of Operational Strategies to Minimize Bromate Formation in the Moorhead Water Treatment Plant
(North Dakota State University, 2014)A recent study at the Moorhead water treatment plant (MWTP) determined that bromate formed during ozone disinfection and, at times, exceeded the maximum contaminant level (MCL) of 10 parts per billion (ppb) in the summer ... -
Identification of Delamination Defects in CFRP Materials through Lamb Wave Responses
(North Dakota State University, 2014)Delamination is currently a largely undetectable form of damage in composite laminate materials. This thesis will develop a method to more easily detect delamination damage within composite materials. Using finite element ... -
Microtopography-Dominated Discontinuous Overland Flow Modeling and Hydrologic Connectivity Analysis
(North Dakota State University, 2014)Surface microtopography affects a series of complex and dynamic hydrologic and environmental processes that are associated with both surface and subsurface systems, such as overland flow generation, infiltration, soil ... -
Hydrologic Experiments and Analysis: The Effect of Microtopography on Runoff Generation
(North Dakota State University, 2014)Microtopography is an important factor in hydrologic processes. The purpose of this research was to study the effects of microtopography on runoff generation. Specifically, this was performed through an array of physical ... -
Infiltration and Unsaturated Flow under the Influence of Surface Microtopography: Model Simulations and Experimental Observations
(North Dakota State University, 2014)Surface microtopography affects fundamental hydrologic processes including infiltration and soil-water percolation at different scales. By means of studying the unsaturated flow, this thesis research is aimed to evaluate ... -
Analysis on Structural Modeling for Recycled Asphalt Pavement used as a Base Layer
(North Dakota State University, 2015)Reusing RAP in the base layer became a common practice in the last decade. However, some crucial issues must be resolved to succeed in using RAP satisfying the standard specifications as a base layer. The most important ...