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Full-Text Articles in Engineering
Natural Organic Matter: A Study Of Long-Term Variability And Anthropogenic Influence, Gregory D. Devine
Natural Organic Matter: A Study Of Long-Term Variability And Anthropogenic Influence, Gregory D. Devine
Environmental & Water Resources Engineering Masters Projects
Disinfection byproducts may be carcinogenic compounds and are present within most drinking water supply systems. These hannful compounds result from an mteraction between natural organic matter and conventional disinfectants such as chlorine or chlorine-based solutions. The level of disinfection byproducts within a distribution system is controlled by federal and state regulations; pending federal regulations propose increasingly stringent allowable levels of disinfection byproducts. The goals of this investigation were to 1) identify long-term variability associated with natural organic matter across the country, 2) develop empirical relationships between anthropogenic activity, land use/land cover and natural organic matter and 3) construct a mechanistic …
Deicer Source Hindcasting In An Unconfined Roadside Aquifer, Ivonne Hall
Deicer Source Hindcasting In An Unconfined Roadside Aquifer, Ivonne Hall
Environmental & Water Resources Engineering Masters Projects
Deicing materials that include calcium magnesium acetate (CMA), road salt, and premix are applied over a 1.2 mile section of the highway on State Route 25 (SR25) in Plymouth, Massachusetts. This part of the highway was designed to route runoff to an infiltration basin. The main goal of this research was to evaluate when and where deicer contamination infiltrated to the groundwater table at the site, with a focus on the infiltration basin. This project evaluated the steady-state hydraulics of the site, as well as the fate and transport of the deicing materials. There are many sources of data available …
Characterization Of Storm Events Using An Automated Sampler, Shem Styger
Characterization Of Storm Events Using An Automated Sampler, Shem Styger
Environmental & Water Resources Engineering Masters Projects
The goal of this research was to evaluate the use of an automated sampler in profiling concentrations of deicing agents in stonnmnoff at a research site in Plymouth, MA. The Massachusetts Highway Department applies a combination of deicing agents in the form of salt, premix and calcium magnesium acetate (CMA) to an 830 m long stretch of State Route 25 during the months of November to April when driving conditions are hazardous. Portions of the applied deicing agents applied are left behind in a depression storage layer which was found to be 2.67 mm. The depression storage layer govems the …
Nonlinear Response Of Head Dependent Boundary Conditions In Modflow, Aparna S. Vemuri
Nonlinear Response Of Head Dependent Boundary Conditions In Modflow, Aparna S. Vemuri
Environmental & Water Resources Engineering Masters Projects
Engineering is the professional art of applying science to the optimum conversion of natural resources to the benefit of man. - Ralph J. Smith Groundwater mining reduces water levels in the subsurface and is found to have grave consequences like natural aquifer depletion. Groundwater management models that couple simulation models with optimization models have been used in the management of groundwater resources. The effect of head dependent boundary conditions on the head response due to pumping stresses is studied along with its impact on management strategies. Hypothetical aquifer models have been set up using MODFLOW 2000 and groundwater management (GWM) …
Multiple Imputation Scheme For Overcoming The Missing Values And Variability Issues In Its Data, Daiheng Ni, John D. Leonard Ii, Angshuman Guin, Chunxia Feng
Multiple Imputation Scheme For Overcoming The Missing Values And Variability Issues In Its Data, Daiheng Ni, John D. Leonard Ii, Angshuman Guin, Chunxia Feng
Daiheng Ni
Traffic engineering studies such as validating Highway Capacity Manual (HCM) models require complete and reliable field data. However, the wealth of intelligent transportation systems (ITS) data is sometimes rendered useless for these purposes because of missing values in the data. Many imputation techniques have been developed in the past with virtually all of them imputing a single value for a missing datum. While this provides somewhat simple and fast estimates, it does not eliminate the possibility of producing biased results and it also fails to account for the uncertainty brought about by missing data. To overcome these limitations, a multiple …
Water Distribution Analysis And Modeling For Stamford, Connecticut, Robert W. Best
Water Distribution Analysis And Modeling For Stamford, Connecticut, Robert W. Best
Environmental & Water Resources Engineering Masters Projects
The Aquarion Water Company (AWe) has funded several research studies. Performed by graduate students at the University of Massachusetts at Amherst, including this research on the Stamford, Connecticut water distribution system (WDS). Some of the recent research has been performed in response to the proposed Stage II Disinfectants/Disinfection By-Product (DBP) Rule (S2DDBPR) (US EPA, 2003). Due to the new requirements that fall under the pmposed S2DDBPR, an initial distribution system evaluation (IDSE) on the Stamford WDS is required to locate potential monitoring sites for compliance with DSP regulations. Between July 2002 and August 2003, three field study events (summer 2002, …
Modeling Natural, Organic Matter In An Unfiltered Surface Water Supply, Daniel R. Buttrick
Modeling Natural, Organic Matter In An Unfiltered Surface Water Supply, Daniel R. Buttrick
Environmental & Water Resources Engineering Masters Projects
Wachusett Reservoir, located in central Massachusetts, supplies water to the Boston, Massachusetts metropolitan area. The reservoir receives water from a watershed of 117 square miles, as well as water transferred from the Quabbin Reservoir to the west. Quabbin Reservoir water generally has lower levels of most water quality constituents than water received from the Wachusett Reservoir watershed. The Massachusetts Department of Conservation and Recreation (DCR) manages the watershed and monitors tributary and in-reservoir water quality, while the Massachusetts Water Resources Authority (MWRA) is responsible for treatment and distribution. CE QUAL W2 is a two dimensional, laterally averaged water quantity and …
Markov Chain Monte Carlo Multiple Imputation For Incomplete Its Data Using Bayesian Networks, Daiheng Ni, John D. Leonard
Markov Chain Monte Carlo Multiple Imputation For Incomplete Its Data Using Bayesian Networks, Daiheng Ni, John D. Leonard
Daiheng Ni
The rich ITS data is a precious resource for transportatio n researchers and practitioners. However, the usability of such resource is greatly limited by the issue of data missing. A lot of imputation methods have been proposed in the past decade. However, some issues ar e still not or not sufficiently addresse d. For example, the missing of entire records, temporal correlation in observations, natural char acteristics in raw data, and unbiased estimates for missing values. With these in mind, this paper proposes an advanced imputation method which is based on the recent development in other disciplines, especially applied statistics …