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Full-Text Articles in Engineering
Chemical Sensor Resolution Requirements For Near-Surface Measurements Of Turbulent Fluxes, M. D. Rowe, C. W. Fairall, J. A. Perlinger, J. A. Perlinger
Chemical Sensor Resolution Requirements For Near-Surface Measurements Of Turbulent Fluxes, M. D. Rowe, C. W. Fairall, J. A. Perlinger, J. A. Perlinger
Michigan Tech Publications
Businger and Delany (1990) presented an approach to estimate the sensor resolution required to limit the contribution of the uncertainty in the chemical concentration measurement to uncertainty in the flux measurement to 10 % for eddy covariance, gradient, and relaxed eddy accumulation flux measurement methods. We describe an improvement to their approach to estimate required sensor resolution for the covariance method, and include disjunct eddy covariance. In addition, we provide data to support selection of a form for the dimensionless scalar standard deviation similarity function based on observations of the variance of water vapor fluctuations from recent field experiments. We …
Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, J. S. Fu, S. Wu, L. J. Mickley
Impacts Of Future Climate Change And Effects Of Biogenic Emissions On Surface Ozone And Particulate Matter Concentrations In The United States, Y. F. Lam, J. S. Fu, S. Wu, L. J. Mickley
Michigan Tech Publications
Simulations of present and future average regional ozone and PM 2.5 concentrations over the United States were performed to investigate the potential impacts of global climate change and emissions on regional air quality using CMAQ. Various emissions and climate conditions with different biogenic emissions and domain resolutions were implemented to study the sensitivity of future air quality trends from the impacts of changing biogenic emissions. A comparison of GEOS-Chem and CMAQ was performed to investigate the effect of downscaling on the prediction of future air quality trends. For ozone, the impacts of global climate change are relatively smaller when compared …
Sediment Yield Reduction In An Agricultural Watershed, Lijun Chen
Sediment Yield Reduction In An Agricultural Watershed, Lijun Chen
Dissertations, Master's Theses and Master's Reports - Open
With proper application of Best Management Practices (BMPs), the impact from the sediment to the water bodies could be minimized. However, finding the optimal allocation of BMP can be difficult, since there are numerous possible options. Also, economics plays an important role in BMP affordability and, therefore, the number of BMPs able to be placed in a given budget year. In this study, two methodologies are presented to determine the optimal cost-effective BMP allocation, by coupling a watershed-level model, Soil and Water Assessment Tool (SWAT), with two different methods, targeting and a multi-objective genetic algorithm (Non-dominated Sorting Genetic Algorithm II, …
Investigation Of Using Waste Engine Oil Blended With Reclaimed Asphalt Materials To Improve Pavement Recyclability , Christopher Daniel Dedene
Investigation Of Using Waste Engine Oil Blended With Reclaimed Asphalt Materials To Improve Pavement Recyclability , Christopher Daniel Dedene
Dissertations, Master's Theses and Master's Reports - Open
With the increasing importance of conserving natural resources and moving toward sustainable practices, the aging transportation infrastructure can benefit from these ideas by improving their existing recycling practices. When an asphalt pavement needs to be replaced, the existing pavement is removed and ground up. This ground material, known as reclaimed asphalt pavement (RAP), is then added into new asphalt roads. However, since RAP was exposed to years of ultraviolet degradation and environmental weathering, the material has aged and cannot be used as a direct substitute for aggregate and binder in new asphalt pavements. One material that holds potential for restoring …
Life Cycle Assessment Of Trayless Dining , Nawaf Isam Blaisi
Life Cycle Assessment Of Trayless Dining , Nawaf Isam Blaisi
Dissertations, Master's Theses and Master's Reports - Open
Universities in the United States are applying more sustainable approaches to their dining service operations. "The increase in social consciousness and environmental stewardship on college campuses has spurred an array of new and innovative sustainability programs"(ARAMARK Higher Education 2008). University residence dining is typically cafeteria style, with students using trays to carry food. Studies report that food served without trays substantially reduces food waste and water and electrical consumption associated with washing trays. Commonly, these reported results are estimates and not measurements taken under actual operating conditions.
This study utilizes measurements recorded under actual dining service conditions in student residence …
Creep And Shrinkage Behavior Of Ultra High-Performance Concrete Under Compressive Loading With Varying Curing Regimes , Jason C. Flietstra
Creep And Shrinkage Behavior Of Ultra High-Performance Concrete Under Compressive Loading With Varying Curing Regimes , Jason C. Flietstra
Dissertations, Master's Theses and Master's Reports - Open
This Ultra High Performance Concrete research involves observing early-age creep and shrinkage under a compressive load throughout multiple thermal curing regimes. The goal was to mimic the conditions that would be expected of a precast/prestressing plant in the United States, where UHPC beams would be produced quickly to maximize a manufacturing plant’s output. The practice of steam curing green concrete to accelerate compressive strengths for early release of the prestressing tendons was utilized (140°F [60°C], 95% RH, 14 hrs), in addition to the full thermal treatment (195°F [90°C], 95% RH, 48 hrs) while the specimens were under compressive loading. Past …
Mechanisms Contributing To The Deep Chlorophyll Maximum In Lake Superior, Marcel L. Dijkstra
Mechanisms Contributing To The Deep Chlorophyll Maximum In Lake Superior, Marcel L. Dijkstra
Dissertations, Master's Theses and Master's Reports - Open
The seasonal appearance of a deep chlorophyll maximum (DCM) in Lake Superior is a striking phenomenon that is widely observed; however its mechanisms of formation and maintenance are not well understood. As this phenomenon may be the reflection of an ecological driver, or a driver itself, a lack of understanding its driving forces limits the ability to accurately predict and manage changes in this ecosystem. Key mechanisms generally associated with DCM dynamics (i.e. ecological, physiological and physical phenomena) are examined individually and in concert to establish their role. First the prevailing paradigm, “the DCM is a great place to live”, …
Cladophora, Mass Transport, And The Nearshore Phosphorus Shunt , Aaron I. Dayton
Cladophora, Mass Transport, And The Nearshore Phosphorus Shunt , Aaron I. Dayton
Dissertations, Master's Theses and Master's Reports - Open
Excessive Cladophora growth in the Great Lakes has led to beach fouling and the temporary closure of nuclear power plants and has been associated with avian botulism and the persistence of human pathogens. As the growth-limiting nutrient for Cladophora, phosphorus is the appropriate target for management efforts. Dreissenids (zebra and quagga mussels) have the ability to capture particulate phase phosphorus (otherwise unavailable to Cladophora) and release it in a soluble, available form. The significance of this potential nutrient source is, in part, influenced by the interplay between phosphorus flux from the mussel bed and turbulent mixing in establishing …
Development Of A Physically-Based Method For Delineation Of Hydrologically Homogeneous Regions And Flood Quantile Estimation In Ungauged Basins Via The Index Flood Method, Fredline Ilorme
Dissertations, Master's Theses and Master's Reports - Open
Regional flood frequency techniques are commonly used to estimate flood quantiles when flood data is unavailable or the record length at an individual gauging station is insufficient for reliable analyses. These methods compensate for limited or unavailable data by pooling data from nearby gauged sites. This requires the delineation of hydrologically homogeneous regions in which the flood regime is sufficiently similar to allow the spatial transfer of information. It is generally accepted that hydrologic similarity results from similar physiographic characteristics, and thus these characteristics can be used to delineate regions and classify ungauged sites. However, as currently practiced, the delineation …
Determining Bridge Deck Deterioration Through The Use Of 3d Photogrammetry , Darrin C. Evans
Determining Bridge Deck Deterioration Through The Use Of 3d Photogrammetry , Darrin C. Evans
Dissertations, Master's Theses and Master's Reports - Open
The bridge inspection industry has yet to utilize a rapidly growing technology that shows promise to help improve the inspection process. This thesis investigates the abilities that 3D photogrammetry is capable of providing to the bridge inspector for a number of deterioration mechanisms. The technology can provide information about the surface condition of some bridge components, primarily focusing on the surface defects of a concrete bridge which include cracking, spalling and scaling. Testing was completed using a Canon EOS 7D camera which then processed photos using AgiSoft PhotoScan to align the photos and develop models. Further processing of the models …
Evaluation Of The Performance And Cost-Effectiveness Of Pavement Sections Containing Open-Graded Base Courses, Abdul A. Koroma
Evaluation Of The Performance And Cost-Effectiveness Of Pavement Sections Containing Open-Graded Base Courses, Abdul A. Koroma
Dissertations, Master's Theses and Master's Reports - Open
Moisture induced distresses have been the prevalent distress type affecting the deterioration of both asphalt and concrete pavement sections. While various surface techniques have been employed over the years to minimize the ingress of moisture into the pavement structural sections, subsurface drainage components like open-graded base courses remain the best alternative in minimizing the time the pavement structural sections are exposed to saturated conditions. This research therefore focuses on assessing the performance and cost-effectiveness of pavement sections containing both treated and untreated open-graded aggregate base materials.
Three common roadway aggregates comprising of two virgin aggregates and one recycled aggregate were …
Discrete Element Methods For Asphalt Concrete : Development And Application Of User-Defined Microstructural Models And A Viscoelastic Micromechanical Model , Yu Liu
Dissertations, Master's Theses and Master's Reports - Open
As an important Civil Engineering material, asphalt concrete (AC) is commonly used to build road surfaces, airports, and parking lots. With traditional laboratory tests and theoretical equations, it is a challenge to fully understand such a random composite material. Based on the discrete element method (DEM), this research seeks to develop and implement computer models as research approaches for improving understandings of AC microstructure-based mechanics. In this research, three categories of approaches were developed or employed to simulate microstructures of AC materials, namely the randomly-generated models, the idealized models, and image-based models. The image-based models were recommended for accurately predicting …
Accounting For Warping And Differential Drying Shrinkage Mechanisms In The Design Of Jointed Plain Concrete Payments, Rita Elizabeth Lederle
Accounting For Warping And Differential Drying Shrinkage Mechanisms In The Design Of Jointed Plain Concrete Payments, Rita Elizabeth Lederle
Dissertations, Master's Theses and Master's Reports - Open
When a concrete slab experiences differential volume change due to temperature, moisture, and shrinkage gradients, it deforms. The stresses induced by these differential volume changes can reduce the pavement’s fatigue life. Differential volume change is quantified by the equivalent temperature difference required to deform a comparable flat slab to the same shape as the actual slab. This thesis presents models to predict the equivalent temperature difference due to moisture warping and differential drying shrinkage. Moisture warping occurs because a portion of drying shrinkage is reversible, while differential drying shrinkage is due to the irreversible portion of drying shrinkage. The amount …
Comparative Study Of Anchorage Strengths Of Epoxy Coated Hooked Bars , Paul W. Koning
Comparative Study Of Anchorage Strengths Of Epoxy Coated Hooked Bars , Paul W. Koning
Dissertations, Master's Theses and Master's Reports - Open
Hooked reinforcing bars (rebar) are used frequently to carry the tension forces developed in beams and transferred to columns. Research into epoxy coated hooked bars has only been minimally performed and no research has been carried out incorporating the coating process found in ASTM A934. This research program compares hooked rebar that are uncoated, coated by ASTM A775, and coated by ASTM A934.
In total, forty-two full size beam-column specimens were created, instrumented and tested to failure. The program was carried out in three phases. The first phase was used to refine the test setup and procedures. Phase two explored …
Nitrogen Oxides In The Firn Air At Summit, Greenland, Claudia Toro
Nitrogen Oxides In The Firn Air At Summit, Greenland, Claudia Toro
Dissertations, Master's Theses and Master's Reports - Open
Measurements of NOx within the snowpack at Summit, Greenland were carried out from June 2008 to July 2010, using a novel system to sample firn air with minimal disruption of the snowpack. These long-term measurements were motivated by the need of improving the representation of air-snow interactions in global models. Results indicated that the NOx budget within the snowpack was on the order of 550 pptv as maximum, and was constituted primarily for NO2. NOx production was observed within the first 50 cm of the snowpack during the sunlight season between February and August. Presence of NOx at larger depths …
Structural Capacity Of Steel Tubular Cast-In-Place Piling , Kevin A. Mears
Structural Capacity Of Steel Tubular Cast-In-Place Piling , Kevin A. Mears
Dissertations, Master's Theses and Master's Reports - Open
Steel tubular cast-in-place pilings are used throughout the country for many different project types. These piles are a closed-end pipe with varying wall thicknesses and outer diameters, that are driven to depth and then the core is filled with concrete. These piles are typically used for smaller bridges, or secondary structures. Mostly the piling is designed based on a resistance based method which is a function of the soil properties of which the pile is driven through, however there is a structural capacity of these members that is considered to be the upper bound on the loading of the member. …
Numerical Study On The Curling And Warping Of Hardened Rigid Pavement Slabs, Qin Yinghong
Numerical Study On The Curling And Warping Of Hardened Rigid Pavement Slabs, Qin Yinghong
Dissertations, Master's Theses and Master's Reports - Open
In-service hardened concrete pavement suffers from environmental loadings caused by curling and warping of the slab. Traditionally, these loadings are computed on the basis of treating the slab as an elastic material, and of evaluating separately the curling and warping components. This dissertation simulates temperature distribution and moisture distribution through the slabs by use of a developed numerical model that couples the heat transfer and moisture transport. The computation of environmental loadings treats the slab as an elastic-viscous material, which considers the relaxation behavior and Pickett effect of the concrete.
The heat transfer model considers the impacts of solar radiation, …
Comparison Of Paser And Pci Pavement Distress Indices , Timothy P. Barrette
Comparison Of Paser And Pci Pavement Distress Indices , Timothy P. Barrette
Dissertations, Master's Theses and Master's Reports - Open
No abstract provided.
Assessing Drinking Water Quality At Source And Point-Of-Use : A Case Study Of Koila Bamana, Mali, West Africa , Mathew D. Seib
Assessing Drinking Water Quality At Source And Point-Of-Use : A Case Study Of Koila Bamana, Mali, West Africa , Mathew D. Seib
Dissertations, Master's Theses and Master's Reports - Open
Ensuring water is safe at source and point-of-use is important in areas of the world where drinking water is collected from communal supplies. This report describes a study in rural Mali to determine the appropriateness of assumptions common among development organizations that drinking water will remain safe at point-of-use if collected from a safe (improved) source. Water was collected from ten sources (borehole wells with hand pumps, and hand-dug wells) and forty-five households using water from each source type. Water quality was evaluated seasonally (quarterly) for levels of total coliform, E.coli, and turbidity. Microbial testing was done using the …
Incorporating Environmental Engineering And Science Topics Into Elementary Education , Jessica G. Billings
Incorporating Environmental Engineering And Science Topics Into Elementary Education , Jessica G. Billings
Dissertations, Master's Theses and Master's Reports - Open
No abstract provided.
Performance Characteristics And Design Recommendations For Biomass-Burning Stoves Using Earthen Construction Materials , Nicholas H. Schreiner
Performance Characteristics And Design Recommendations For Biomass-Burning Stoves Using Earthen Construction Materials , Nicholas H. Schreiner
Dissertations, Master's Theses and Master's Reports - Open
This report provides an analysis of the thermal performance and emissions characteristics of improved biomass stoves constructed using earthen materials. Commonly referred to as mud stoves, this type of improved stove incorporates high clay content soil with an organic binder in the construction of its combustion chamber and body. When large quantities of the mud material are used to construct the stove body, the stove does not offer significant improvements in fuel economy or air quality relative to traditional open fire cooking. This is partly because a significant amount of heat is absorbed by the mass of the stove reducing …
Hydrologic Analysis Of A Limestone Quarry Using Epa's Help Version 3.08 Model , Scott R. Bauer
Hydrologic Analysis Of A Limestone Quarry Using Epa's Help Version 3.08 Model , Scott R. Bauer
Dissertations, Master's Theses and Master's Reports - Open
Aggregates were historically a low cost commodity but with communities and governmental agencies reducing the amount of mining the cost is increasing dramatically. An awareness needs to be brought to communities that aggregate production is necessary for ensuring the existing infrastructure in today’s world. This can be accomplished using proven technologies in other areas and applying them to show how viable reclamation is feasible.
A proposed mine reclamation, Douglas Township quarry (DTQ), in Dakota Township, MN was evaluated using Visual Hydrologic Evaluation of Landfill Performance (HELP) model. The HELP is commonly employed for estimating the water budget of a landfill, …
Retrofitting Boreholes Contaminated With Iron In Rural Uganda , Caleb T. Fader
Retrofitting Boreholes Contaminated With Iron In Rural Uganda , Caleb T. Fader
Dissertations, Master's Theses and Master's Reports - Open
During my Peace Corps service as a community health liaison in rural Uganda I noticed that many improved water wells in our area had been abandoned. The communities described the water in these wells as being reddish in color, having a foul taste and odor, discoloring clothes and food, and not able to produce lather for washing.
Personal investigations and an initial literature search suggested that the primary contaminant was iron. The water in these wells had a low pH and a rusty metallic smell. The water produced early in the morning appeared very red but the water became more …
Michigan Cone Test : A Reliability Study, Karl M. Krueger
Michigan Cone Test : A Reliability Study, Karl M. Krueger
Dissertations, Master's Theses and Master's Reports - Open
No abstract provided.
Review Of Assessment, Design, And Mitigation Of Multiple Hazards, Aakash Ahuja
Review Of Assessment, Design, And Mitigation Of Multiple Hazards, Aakash Ahuja
Dissertations, Master's Theses and Master's Reports - Open
Large parts of the world are subjected to one or more natural hazards, such as earthquakes, tsunamis, landslides, tropical storms (hurricanes, cyclones and typhoons), costal inundation and flooding. Virtually the entire world is at risk of man-made hazards. In recent decades, rapid population growth and economic development in hazard-prone areas have greatly increased the potential of multiple hazards to cause damage and destruction of buildings, bridges, power plants, and other infrastructure; thus posing a grave danger to the community and disruption of economic and societal activities. Although an individual hazard is significant in many parts of the United States (U.S.), …
Rural Water System Sustainability : A Case Study Of Community-Managed Water Systems In Saramaka Communities , Gwynneth Smith
Rural Water System Sustainability : A Case Study Of Community-Managed Water Systems In Saramaka Communities , Gwynneth Smith
Dissertations, Master's Theses and Master's Reports - Open
Worldwide, rural populations are far less likely to have access to clean drinking water than are urban ones. In many developing countries, the current approach to rural water supply uses a model of demand-driven, community-managed water systems. In Suriname, South America rural populations have limited access to improved water supplies; community-managed water supply systems have been installed in several rural communities by nongovernmental organizations as part of the solution. To date, there has been no review of the performance of these water supply systems. This report presents the results of an investigation of three rural water supply systems constructed in …
Study Of Water Use And Supply In The District Of Independencia, Peru, Fletcher A. Mckenzie
Study Of Water Use And Supply In The District Of Independencia, Peru, Fletcher A. Mckenzie
Dissertations, Master's Theses and Master's Reports - Open
Peru is a developing country with abundant fresh water resources, yet the lack of infrastructure leaves much of the population without access to safe water for domestic uses. The author of this report was a Peace Corps Volunteer in the sector of water & sanitation in the district of Independencia, Ica, Peru. Independencia is located in the arid coastal region of the country, receiving on average 15 mm of rain annually. The water source for this district comes from the Pisco River, originating in the Andean highlands and outflowing into the Pacific Ocean near the town of Pisco, Peru.
The …
Tropospheric Ozone And Co Over North Atlantic For The Past Decade, Mark F. Weise
Tropospheric Ozone And Co Over North Atlantic For The Past Decade, Mark F. Weise
Dissertations, Master's Theses and Master's Reports - Open
We investigate how declines in US emissions of CO and O3 precursors have impacted the lower free troposphere over the North Atlantic. We use seasonal observations for O3 and CO from the PICO-NARE project for the period covering 2001 to 2010. Observations are used to verify model output generated by the GEOS-Chem 3-D global chemical transport model. Additional satellite data for CO from AIRS/Aqua and for O3 from TES/Aura were also used to provide additional comparisons; particularly for fall, winter, and spring when PICO-NARE coverage is sparse. We find GEOS-Chem captures the seasonal cycle for CO and O3 well compared …