Engineering Commons^™

Intermodal Commuter Network Planning, Maria P. Boile

Dissertations

An intermodal commuter network is an integration of passenger transportation systems, or modes, to a single comprehensive system that provides connections among the various modes, and improved travel choices to users. In the system examined in this dissertation, commuters access their final destination via auto, rail, and intermodal auto-to-rail modes. There are numerous highway paths by which a commuter can reach the final destination. Once on the highway, the commuter can switch to rail at stations along the rail route. The commuter may also choose to walk to the rail station closest to the trip's origin.

The main focus of …

A Theoretical Analysis Of Volatile Contaminant Removal By The Pneumatic Fracturing Process, Yuan Ding

Dissertations

A mathematical model that simulates the process of contaminant removal from a pneumatically induced fracture within a porous medium is presented. It includes: (1) model development; (2) parameter evaluation; (3) statistical sensitivity analysis; and (4) model validation.

Based on the dual porosity approach, a mathematical model for a fractured porous formation is developed for both two dimensional and axial symmetrical cases. This model constitutes a pair of coupled partial differential equations for the porous medium and discrete fracture, respectively. The initial and boundary conditions have been determined based on field considerations of a soil vapor extraction system. By means of …

Optimizing Rail-Truck Intermodal Drayage Operations, Wen Zhang

Theses

This thesis presents a case study of the trucking (or drayage) portion of rail-truck intermodal freight transportation. The approach used was to examine in detail the current costs and potential for improvement at one New Jersey intermodal terminal. The analysis is conducted using a mathematical programming model to find an optimal scheduling plan for the drayage operation. To solve the model more efficiently, a modification is made to explore the special structure of the original problem which has a sparse constraint matrix. The model is solved first with an objective function that minimizes the total cost of the operation, and …

A Study Of Settlement In Landfills Due To Biodegradation, Michael Guasconi

Theses

Finding new space for landfills is difficult due to land availability, stringent environmental regulations, and public sentiment. So other means of waste disposal, such as hauling it to a distant landfill, or incinerating it, will have to be resorted to. These methods may be unpopular with the public involved. By studying settlement due to biodegradation, ways to increase settlement can be found, allowing for additional waste disposal capacity in operating, and closed landfills.

Existing theoretical models are based on rheological concepts, not on biodegradation. So, they do not realistically model settlement. In this study, a model to determine the rate, …

Reverse Osmosis As A Pretreatment Of Ion Exchange Equipment At Pse & G'S Hudson Generation Station, Steven Leon

Theses

Public Service Electric and Gas Company's Hudson Generating Station has historically had problems providing sufficient high quality water for its two once through, supercritical design boilers. The station requires over 60 million gallons annually to compensate for system losses.

The stations' ion exchange demineralizers proved to be costly to operate and overall inefficient in performance. Drawbacks include: short service cycles, periodic contamination of storage tanks due to premature breakthrough, prohibitively high chemical regenerant costs, excessive labor requirements, frequent resin replacement, and overall unreliable plant operations.

A reverse osmosis unit was installed as a pretreatment to the demineralizers to offset these …

Congestion Management Systems Development And Implementation : Four Case Studies, Arlene Rose-Marie Willis

Theses

To address concerns of poor air quality, congested highways and the need to manage and plan for transportation within budgetary constraints, the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) mandated the development and implementation of a Congestion Management System (CMS). Primarily, a CMS will fuel transportation decision making with information on system performance and alternate strategies to alleviate congestion and enhance mobility. Efforts through ISTEA are expected to produce a more efficient American transportation system -- this thesis takes a look at the preparatory activities.

It is based on a federally funded project with metropolitan planning organizations (MPOs) in …

Shear Strength And Fatigue Crack Propagation In Concrete By Energy Method, Wei Wang

Dissertations

The limit analysis methods have been commonly used to predict the ultimate flexure strength of reinforced concrete members over 50 years. However, current design formulas for shear in structural concrete are mostly empirical. In part one of this dissertation, attempts are made to apply the theory of plasticity to predict the shear strengths of reinforced concrete structures.

The modified Coulomb-Mohr failure criterion is used as the constitutive law of concrete, and the plastic flow is assumed to be associated with this failure criterion. A generalized formulation for energy dissipation in accordance with the failure criterion and associated flow rule is …

A Nondestructive Method For The Determination Of Fracture Energy In Concrete Structures, Been-Jyh Yu

Dissertations

It is generally believed that linear elastic fracture mechanics concepts can not be employed in determining fracture parameters in concrete, and therefore most of the current research effort has focused on applying the principles in yielding fracture mechanics. Despite all these efforts, comparison of results reported by many investigators indicate wide variations in fracture toughness values even for essentially similar materials. The main source of discrepancy in the observed results is the existence of a large process zone at the crack tip. Hence, the amount of energy consumed in advancing the crack will depend on the size of the process …

Composite Beam Analogy Fracture Model (Cbafm) : A Non-Linear Fracture Mechanics Model For Concrete, Mohammed Enamul Haque

Dissertations

The main objective of this dissertation is to develop a simple non-linear fracture mechanics model for the determination of fracture mechanics parameters for concrete, such as fracture process zone length (rp), critical fracture energy release rate (Gic), critical stress intensity factor (KO and fracture energy (GF). The fracture process zone (FPZ) is modeled as a damaged non-elastic cohesive band where the extent of damage due to microcracking varies from no damage at the boundary of FPZ to complete crack surface separation at the notch or macro-crack tip. The proposed method can predict theoretically both the pre-peak and post-peak load versus …

Fundamentals Of Adhesion Of Organic Compounds And Aqueous Cleaning Of Glass And Metal Surfaces : Applications In The Pharmaceutical And Chemical Industries, Michel J. De Ruijter

Theses

In this thesis we studied the physics and chemistry of the adhesion of various classes of organic compounds to glass and stainless steel surfaces, by using diagnostic aqueous cleaning solutions and other techniques. We defined the thermodynamic requirements for aqueous cleaning based on extensive experimental and theoretical work. Novel cleaning diagrams are introduced, based on electrostatic interactions between organic compounds and solid surfaces, to facilitate the design of aqueous cleaning systems. We studied the mass transfer parameters for selected situations. The electrochemical Pourbaix-diagrams were used to explain the effect of hydrogen peroxide added to aqueous solutions and to avoid corrosion …

Integration Of Pneumatic Fracturing And In Situ Vitrification In Coarse Grained Soils, Sean Thomas Mcgonigal

Theses

This thesis investigates conceptual integration of the Pneumatic Fracturing (PF) process with In Situ Vitrification (ISV) for remediation of contaminated soil. Integration will permit ISV melts to be initiated below the ground surface and extend the depth of the ISV process.

Bench scale experiments were conducted in 4.9 ft³ (0.14 m³) Plexiglas tanks filled with a test soil that was specifically blended to simulate the Hanford Formation in Richland, WA. Discrete pneumatic fractures were successfully created and filled with the ISV starter path material. Conductivity measurements made across two graphite electrodes exhibited a pre-fracture soil resistance of …

A Study Of Transit Corridors Within The Njtpa Region, Mark Kagen Berger

Theses

Identifying potential bus and rail transit corridors for the North Jersey Transportation Planning Authority (NJTPA) region by examining current travel patterns of commuters was the purpose of this thesis. The current transit corridors within the NJTPA region was discussed first, followed by the methods for selecting specific municipalities for analysis. At this point, specific examinations of the selected municipalities' origin and destination travel patterns were mapped. The results were then summed up, along with a discussion of potential new bus and rail transit corridors based on trips originating along a corridor enroute to the same municipality. The final discussion examined …

Hydrodynamic And Water Quality Modeling Of The Whippany River, John E. Krohn

Theses

The Whippany River is located in northern New Jersey and is a major tributary to the Passaic River System. This waterway accepts a wide variety of wastes from the diverse communities within its watershed. These wastes contribute to a rather complex network of biological, chemical and physical interactions.

The purpose of this study is to develop a water quality model using QUAL2E. This model will be used as a tool to simulate the complex interactions that take place within the river system. The river must he considered from physical, biological and chemical perspectives. A successful model can determine current water …

Reducing Rail-Truck Freight Intermodal Drayage Costs, David Moy Jr.

Theses

In rail-truck intermodal transport, a highway truck-trailer or container is moved by truck from a shipper to a rail terminal in the shipper's vicinity, and by rail in line haul between rail terminals. Upon being unloaded at the destination rail terminal, the container is delivered to a receiver (consignee) by truck. The highway portion of the move, or drayage, accounts for a relatively high percentage of total origin to destination cost, and it limits severely the competitiveness of intermodal service with door-to-door truck service. The approach used in this thesis is to examine in detail the current costs and potential …

Micromechanics Of Hot Mix Asphalt Material Formulation And Numerical Simulation, Kuo-Neng G. Chang

Dissertations

Hot Mix Asphalt (HMA), a highway and airfield pavement material, is heterogeneous, granular, and composite. It is traditionally modeled as a homogeneous material using continuum mechanics or semi-empirical methods. As a result, the above models either neglect or over-simply component reactions, failing to predict field performance problems resulting from particle segregation. This research presents micromechanical modeling, a novel approach that accounts for the components.

A micromechanical model is developed for HMA by modeling it as an assembly of asphalt cement coated particles. The asphalt cement is modeled as a viscoelastic material. To represent asphalt cement, several viscoelastic elements (i.e. Maxwell, …

Analysis Of Plates And Reinforced Concrete Columns By Cubic B-Spline Function, Gang Wang

Dissertations

Applying spline functions to numerical structural analysis has been more common in recent years. The recent increase use of spline functions is mainly due to their excellent characteristics, such as sectionalized continuity, linear combination, flexibility, and easy use for various boundary conditions. The whole deformed shape of some structures or substructures can be described with one displacement function constructed by a series of spline functions. By doing this, the mesh generation and the huge computer memory space are no longer needed because only one single superelement can be used in the whole process. The choice of spline functions as displacement …

Mechanical Behavior Of Polystyrene Foam Bead Lightweight Concrete, Hai-Ying Ni

Theses

This thesis is designed to investigate the effect of porosity on the mechanical properties (strength and modulus) of concrete, and to evaluate the effect of silica fume on the mechanical properties of the polystyrene foam bead lightweight concrete. In this research we made the lightweight concrete by using polystyrene foam beads as light weight aggregate and studied its mechanical properties in detail. Due to the near zero density and modulus of foam beads, we were able to consider it as "porosity". We could then control porosity in concrete by varying foam bead volume fraction.

In our experiments we used the …

Stress-Strain Behavior Of High Strength Concrete Cylinders, Danqing Chen

Theses

Due to the recent development of high strength concrete in engineering and construction, it has become more important to study the behavior of materials in structures.

No results have been previously published in the literature regarding the influence of aspect ratio in plain high strength concrete cylinders on stress-strain behavior under uniaxial compression.Thus at present study, compression tests were conducted on 3x6 in., 3x9 in., and 3x12 in. plain high strength concrete cylinders to study their stress-strain behavior. Plain normal strength concrete cylinders were also tested and used for comparative study.

Based on the present investigations, attempting to obtain a …

A Comparison Between Revealed Preference (Rp) And Stated Preference (Sp) Based On Results Of Simulations, Qiuzi Chen

Theses

This research quantifies the potential biases resulted from two different data generation methods used in transportation modeling: Revealed Preference (RP) and Stated Preference (SP) techniques. Revealed Preference technique is the conventional approach to generate data. It relies on observed or reported data of actual behavior. Stated preference technique is a new data generation method. It creates transportation scenarios using hypothetical data. Conventional studies favor the use of revealed reference. However, full description of advantages and weaknesses of using revealed preference technique is not available in literature, neither point-to-point comparison between stated preference and revealed preference techniques. This research contributes to …