Engineering Commons^™

The Effect Of Intellidrive On The Efficiency Of Highway Transportation Systems, Mohammad Nekoui, Hossein Pishro-Nik, Daiheng Ni

Daiheng Ni

Recently, the IntelliDrive initiative has been proposed by the US Department of Transportation (USDOT) to enhance on-road safety and efficiency. In this study, we provide a mathematical framework which predicts the effect of such technologies on the efficiency of multilane highway systems prior to their real-life deployment. Our study shall encompass mixed traffic conditions in which a variety of assisted, automated and unequipped vehicles coexist. We show that intervehicular communications improves the flow of vehicles by reducing the perception-reaction (P-R) times of drivers and, in some cases, allowing for more efficient lane-changing operations. As we shall see, unlike the latter, …

A Spectrum Of Traffic Flow Modeling At Multiple Scales, Daiheng Ni

Daiheng Ni

his paper presents a broad perspective on traffic flow modeling at a spectrum of four scales. Modeling objectives and model properties at each scale are discussed and existing efforts are reviewed. In order to ensure modeling consistency and provide a microscopic basis for macroscopic models, it is critical to address the coupling among models at different scales, i.e. how less detailed models are derived from more detailed models and, conversely, how more detailed models are aggregated to less detailed models. With this understanding, a consistent modeling approach is proposed based on field theory and modeling strategies at each of the …

High-Strength Wastewater Treatment By Microalgae, Xin Yuan

Environmental & Water Resources Engineering Masters Projects

Microalgae spontaneously convert CO2 and supplementary nutrients into biomass in the presence of light via photosynthesis, and at much higher rates than convention oil-producing crops. Algal biomass can then be transformed into methane via anaerobic bacteria-mediated fermentation, or to biodiesel via lipid extraction, as well as other byproducts of secondary metabolism. Production of biofuel by microalgae can be made more sustainable through coupling microalgal biomass production with existing power generation and wastewater treatment infrastructure. On the other hand, integration of algal biofuel production into wastewater treatment plant anaerobic digestion infrastructure has the potential to increase biogas production, decrease high and …

Two-Stage Filtration To Control Manganse And Dbps At The Lantern Hill Water Treatment Plant, Minh Pham

Environmental & Water Resources Engineering Masters Projects

This research involved full- and pilot-scale studies of treatment of the Aquarion Water Company (AWC) Lantern Hill groundwater source. With elevated levels of both dissolved manganese (~0.19 mg/L), dissolved iron (~1.9 mg/L) and natural organic matter (NOM) (~3 mg/L) the existing treatment plant is having difficulty in achieving required manganese removal while maintaining low concentrations of disinfection byproducts (DBPs) in finished water. At full-scale, dissolved manganese in the raw water is removed through pre-filter oxidation and adsorption on iron precipitates via application of free chlorine and permanganate as well as adsorption of dissolved manganese onto MnOx(s) coated filter media (anthracite …

Bench-Scale Assessment Of Low Pressure Membrane Fouling: Characterization And Examination The Role Of Organic Nitrogen Compounds, Anh Hai Nguyen

Open Access Dissertations

The primary goal of this research was to improve understanding of the fouling of low pressure hollow fiber membranes used in drinking water treatment. The major difference of this study compared to other reported studies was the use of a hollow fiber membrane module at operating conditions mimicking those of full-scale practice. Two poly(vinylidene-fluoroethylene) based hollow fiber membranes (A and B) were tested. Different types of fouling indices (total, hydraulic irreversible, chemical irreversible) developed based on a resistance in series model were used to assess membrane performance. Data from bench-scale and full-scale plants were compared to validate the use of …

Stochastic Modeling Of The Equilibrium Speed-Density Relationship, Haizhong Wang

Open Access Dissertations

Fundamental diagram, a graphical representation of the relation among traffic flow, speed, and density, has been the foundation of traffic flow theory and transportation engineering for many years. For example, the analysis of traffic dynamics relies on input from this fundamental diagram to find when and where congestion builds up and how it dissipates; traffic engineers use a fundamental diagram to determine how well a highway facility serves its users and how to plan for new facilities in case of capacity expansion. Underlying a fundamental diagram is the relation between traffic speed and density which roughly corresponds to drivers’ speed …

Preliminary Estimate Of Highway Capacity Benefit Attainable With Intellidrive Technologies, Daiheng Ni, Jia Li, Steven Andrews, Haizhong Wang

Daiheng Ni

Recent development in IntelliDrive and associated Vehicular Ad Hoc Networks (VANET) has stimulated tremendous interests among decision-makers, practitioners, and researchers due to the potential safety and mobility benefits provided by these technologies. A primary concern regarding the deployment of IntelliDrive is degree of market penetration required for effectiveness. This paper proposes an approach to analyze the benefit of highway capacity gained from IntelliDrive. To fulfill this purpose, a model incorporating the effects of IntelliDrive on car following is formulated, based on which a rough estimate of the resulting capacity gain is derived. A simulation study is conducted to verify the …

Regenerating Spent Zeolites With Uv And Uv/H2o2 To Enhance Removal Of Endocrine Disrupting Compounds, Safina Singh

Environmental & Water Resources Engineering Masters Projects

Endocrine disrupting compounds (EDCs) have become contaminants of emerging concern due to their potential for harmful effects on human and ecological health, at low concentrations (ppb). As an alternative to conventional adsorption media, activate carbon, this study investigates feasibility of using high-silica, hydrophobic zeolites for the removal of EDCs through adsorption process. Zeolites are crystalline, porous alumino-silicate with well defined pore structures, and tetrahedral framework.

While traditional media regeneration processes are energy and cost intensive, evidence has been found that zeolites can be regenerated multiple times through relatively inexpensive methods using direct ultraviolet (UV) photolysis and advanced oxidation process (AOP). …

Western Woburn Greenway Study, Jennifer H. Masters, Bryan C. Aldeghi, Eric C. Kells, Maureen C. Pollock, Rebekah Lynne Decourcey, Carol Waag, Youjin Kwon, Kathryn E. Ostermier, Patrick T. Mcgeough, Ryan Patrick Ball

Landscape Architecture & Regional Planning Studio and Student Research and Creative Activity

In spring 2010, the Department of Landscape Architecture and Regional Planning at the University of Massachusetts Amherst was asked to complete a landscape planning study, the “Western Woburn Greenway Study” for the City of Woburn, MA. The study was undertaken by a team of graduate students, supervised by Professor Jack Ahern. The goals of that study are as follows.

The City of Woburn currently has two large parcel groups of undeveloped land, Whispering Hill (the north focus area) and Winning/Shannon Farms (the south focus area) that are, or may become, available for acquisition (see “Scope of Project” below). The first …

Evaluating Alternative Public-Private Partnership Strategies For Existing Toll Roads: Toward The Development Of A Decision Support System, Christopher John Ahmadjian

Open Access Dissertations

Many claim that, with regard to transportation infrastructure, only partnerships between public and private entities, which draw on the strengths of both, can achieve the goals of enhancing operational efficiency, increasing service delivery, improving asset maintenance, and stretching scarce federal, state, and local tax dollars. While some completed public-private partnership (P3) agreements on existing toll roads in the United States have seen a measure of success, others have raised critical questions pertaining to the true costs and benefits associated with these agreements for all stakeholders. Of particular concern is an apparent reliance on monetary calculations alone to determine toll road …

Route Choice Behavior In Risky Networks With Real-Time Information, Michael D. Razo

Masters Theses 1911 - February 2014

This research investigates route choice behavior in networks with risky travel times and real-time information. A stated preference survey is conducted in which subjects use a PC-based interactive maps to choose routes link-by-link in various scenarios. The scenarios include two types of maps: the first presenting a choice between one stochastic route and one deterministic route, and the second with real-time information and an available detour. The first type measures the basic risk attitude of the subject. The second type allows for strategic planning, and measures the effect of this opportunity on subjects' choice behavior.

Results from each subject are …

A Quantitative Analysis Of The Impacts From Selected Variables Upon Safety Belt Usage In Massachusetts, Samuel W. Gregorio

Masters Theses 1911 - February 2014

Safety belts are the most effective safety device in vehicles in terms of preventing injuries (1). Every year, safety belt usage data across the nation is collected by the individual states, the District of Columbia, and U.S. territories in a probability-based observational survey. Using this survey, Massachusetts, a secondary seat belt law state, ranked last in safety belt usage in 2008. This percentage was approximately a 2 percent decrease from 2007. This value was not an aberration as within the recent past, Massachusetts, a secondary safety belt law state, has consistently ranked at or near the bottom of the 50 …

Historic Bridge Evaluation Using Finite Element Techniques, Helena M. Charron

Masters Theses 1911 - February 2014

The present study examined the application of modern, computer-based analysis methods to two existing historic bridges in Massachusetts. The first bridge featured in this study is the Woronoco Bridge, a reinforced concrete open spandrel arch bridge that was constructed in 1923. It was hoped that a computer-based, parametric study of this bridge would prove it to be deck-stiffened, similar to select bridges of Swiss engineer Robert Maillart. However, the results do not support that there was any intent to reduce bending in the arch as a result of increasing the stiffness of the bridge deck. Instead, the Woronoco Bridge appears …

Investigation Of The Behavior Of Open Cell Aluminum Foam, Patrick J. Veale

Masters Theses 1911 - February 2014

The study investigates the behavior open cell aluminum foam in scenarios applicable to potential use in structural applications. Behavior was examined through mechanical testing, computer modeling and analytic expressions. Existing assumptions about the foam characteristics that define the elastic properties were expanded to include contributions of axial and shear deformations in addition to bending and were rewritten in terms of the axial and bending stiffness ratios of ligaments. Compressive and tensile tests were performed to gain a measure of the elastic properties of the foam as well as the behavior and failure mechanisms in both loading conditions. The materials used …

Material Characterization And Structural Response Of Historic Truss Bridges, Sean L. Kelton

Masters Theses 1911 - February 2014

Historic truss bridges are examined in this thesis through material characterization of wrought iron and structural evaluation of an early 20th century pony truss bridge. The mechanical properties of wrought iron from six 19th century truss bridges were evaluated through mechanical testing that includes hardness and tension tests. The main findings of this work are: 1) That hardness is a poor predictor of yield and ultimate stress but has some ability in screening iron for iron with low ductility, 2) there is a statistically significant difference in the distribution of yield and ultimate stresses between material samples from different bridges, …

Route Choice Behavior In A Driving Simulator With Real-Time Information, Hengliang Tian

Masters Theses 1911 - February 2014

This research studies travelers' route choice behavior in a driving simulator with real-time information en-route. We investigate whether travelers plan strategically for real-time information en-route or simply select a fixed path from origin to destination at the beginning of a trip, and whether network complexity and a parallel driving task affect subjects' strategic thinking ability. In this study, strategic thinking refers to a traveler's route choice decision taking into account future diversion possibilities downstream enabled by information at the diversion node. All of the subjects in this study participated in driving-simulator-based tests while half of the subjects participated in additional …

Earthquake Engineering Simulation With Flexible Cladding System, Jun Jie Li

Masters Theses 1911 - February 2014

This research investigates the interaction between heavy precast cladding units attached to steel framed buildings. Cladding systems are designed as non-structural components and are not expected to contribute to the energy absorption of the primary structure. However, research has indicated that the cladding system may be designed to reduce the response of the primary structure under seismic excitations. The use of flexible connections between the cladding and primary structural frames may be able to provide beneficial effects to the entire structural response. In this study, a series of earthquake engineering simulations were conducted in OPENSEES to analyze the effects of …

Scenario-Based Analysis Of Transportation Impacts In Case Of Dam Failure Flood Evacuation In Franklin County, Massachusetts (Paper # 10-1352), Haizhong Wang, Steven Andrews, John Collura, Daiheng Ni

Daiheng Ni

Emergency planning is an important practice that allows government officials and planners to prepare for disasters and to make prompt response s that can save lives and property . One of the foremost concern s during an emergency is to save as many lives as possible. Thus, whethe r people can leave the disaster areas safely and efficiently is a prime consideration in emergency planning and management. Usually, transportation planners use a four - step model to predict sy s- tem - level performance regarding how people move from on e place to another , and to determine the network …

Representing The Fundamental Diagram: The Pursuit Of Mathematical Elegance And Empirical Accuracy (Paper # 10-1354), Haizhong Wang, Jia Li, Qian-Yong Chen, Daiheng Ni

Daiheng Ni

The fundamental diagram, as the graphical representation of the relationships among traffic flow, speed, and density, has been the foundation of traffic flow theory and transportation engineering. 75 years after the seminal Greenshields model, a variety of models have been proposed to mathematically represent the speed-density relationship which underlies the fundamental diagram. Observed in these models was a clear path toward two competing goals: mathematical elegance and empirical accuracy. As the latest development of such a pursuit, this paper presents a family of speed-density models with varying numbers of parameters. All of these models perform satisfactorily and have physically meaningful …