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Experimental And Predicted Behavior Of Frp Beam-Columns Including Retrofitting, Ali Al-Huazy

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of a theoretical and experimental study of Fiber Reinforce Polymer (FRP) beam-columns with uniaxial bending and including retrofitting. The research involved the design and fabrication of a testing apparatus which was then used for a series of beam-column tests. Three different types of beam-column cross sections were used, namely, channel section, I-section, and square tube section. Six non-retrofitted beam-columns were tested in addition to two retrofitted ones. The members were subjected to an eccentric vertical load applied through a lever arm generating gradually increasing axial load and uniaxial bending moment up to the maximum load. …

Behavior And Strength Of Pultruded Frp I-Section Columns Including Uniaxial And Biaxial Bending, Emad M. Amin

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of a study of the behavior and strength of pultruded glass fiber reinforced polymer (FRP) I-section columns including uniaxial and biaxial applied bending moments. Also included in the study is a critical assessment of ASCE-LRFD Pre-standard for pultruded FRP structures in view of the rigorous analysis presented herein. The theoretical solution is based on a system of three coupled differential equations of equilibrium combined with pinned flexural and torsional boundary conditions. Effects of induced warping due to second-order terms as well as initial out-of-straightness are accounted-for in the governing differential equations. Detailed investigations into the …

Techno-Economic Analysis Of Protein Concentrate Produced By Flash Hydrolysis Of Microalgae, Alexander Nana Yaw Asiedu

Civil & Environmental Engineering Theses & Dissertations

Process simulation and techno-economic analysis of 95wt.% protein concentrate from microalgae has been performed using SuperPro Designer v. 9.0. This work, first of its kind, is focused on the economic analysis of protein concentrate that includes processes such as microalgae cultivation, harvesting, protein extraction and drying steps. A baseline capacity of 160 MT/day protein concentrate production on commercial basis has been analyzed. This throughput requires 336 MT/day dry algae (54 wt.% protein). The amount of carbon dioxide required to grow this quantum of algae is estimated to be 648 MT/day, which is produced from an in situ 21 MW power …

Comparing Nutrient Recovery Via Rapid (Flash Hydrolysis) And Conventional Hydrothermal Liquefaction Processes For Microalgae Cultivation, Caleb Richard Talbot

Civil & Environmental Engineering Theses & Dissertations

Algal biofuels have the potential to provide a scalable source of renewable fuels in the near future. The high nutrient use in algae cultivation and its recovery and recycling is one of the challenges that may limit the scalability and sustainability of algal biofuels. The present study evaluates the use of Hydrolysate obtained after Flash Hydrolysis (FH) of Scenedesmus at 280 C as a nutrient source for microalgae cultivation. FH Hydrolysate nutrient recycling was compared with low temperature batch Hydrothermal Liquefaction (HTL) nutrient recycling. Oocystis and Scenedesmus were cultivated using Hydrolysate as a partial phosphorous (P) and nitrogen (N) source. …

A Risk Assessment Of The Impacts Of Coastal Flooding And Sea Level Rise On The Existing And New Pump Stations 113, Norfolk, Va, David A. Pezza

Civil & Environmental Engineering Theses & Dissertations

The author assessed the risk to a wastewater pump station and a planned replacement located nearby due to coastal flooding and rising sea levels. The locations for the pump stations are in the Larchmont neighborhood by the Lafayette River tidal estuaries in Norfolk, Virginia. The Lafayette River is a tributary to the Elizabeth River, which flows to the Chesapeake Bay. The low-lying areas along the river are subject to coastal surges caused by tropical and extra-tropical storms that flood the bay.

The region is considered one of the urban areas most exposed to the accelerating rate of rising sea levels. …

Hydrothermal Catalytic Liquefaction And Deoxygenation Of Biomass For Renewable Fuel Production, Sergiy Popov

Civil & Environmental Engineering Theses & Dissertations

In recent years, sub- and supercritical water technologies received an increasing attention because of the numerous advantages they offer for biomass converting into biofuels. Water at elevated temperatures and pressures provides an ideal medium for chemical transformations. It serves as a reactant, reaction medium, and catalyst that helps biomass compounds undergo hydrolysis, depolymerization, dehydration, decarboxylation, and condensation/repolymerization reactions. Biomass is the fourth largest source of energy in the world after coal, oil, and natural gas that has the potential to provide the large scale substitution of hydrocarbon-based liquid transportation fuels and minimize the environmental issues. Biomass typically contains 40-60% oxygen. …

Accuracy Comparison Of Numerical Integration Algorithms For Real-Time Hybrid Simulations, Ganesh Anant Reddy

Civil & Environmental Engineering Theses & Dissertations

The use of accurate numerical integration algorithms is one of the key factors for a successful real-time hybrid simulation (RTHS). In RTHSs, explicit integration algorithms are preferred more than implicit methods since all calculations need to be completed within a given time step during simulation. Explicit methods require the use of effective stiffness and damping for experimental substructures, which are incorporated into the calculation of the integration parameters. In general, those values that are greater than the expected stiffness and damping of the experimental substructure are used to ensure the stability of simulation. If a rate-dependent and nonlinear experimental substructure …

Inelastic Behavior And Strength Of Steel Beam-Columns With Applied Torsion, Mamadou Konate

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of an experimental and theoretical study of the inelastic behavior and strength of steel beam-columns with applied torsion. Although the international steel design specifications contain interaction relations for biaxially loaded beam-columns, the influence of applied torsion on such members has been completely ignored in the past. A series of hollow square section steel members are tested using an apparatus specially designed to apply torsion in the presence of an axial load and biaxial bending. The theoretical analysis involves formulation of a system of materially nonlinear differential equations and their solution based on a finite integral …

Characterizing Queue Dynamics At Signalized Intersections From Probe Vehicle Data, Semuel Yacob Recky Rompis

Civil & Environmental Engineering Theses & Dissertations

Probe vehicles instrumented with location-tracking technologies have become increasingly popular for collecting traffic flow data. While probe vehicle data have been used for estimating speeds and travel times, there has been limited research on predicting queuing dynamics from such data. In this research, a methodology is developed for identifying the travel lanes of the GPS-instrumented vehicles when they are standing in a queue at signalized intersections with multilane approaches. In particular, the proposed methodology exploits the unequal queue lengths across the lanes to infer the specific lanes the probe vehicles occupy. Various supervised and unsupervised clustering methods were developed and …

Java Animated Software For Teaching The Frank-Wolfe Algorithm For Static Traffic Network Equilibrium, Zhi Li

Computational Modeling & Simulation Engineering Theses & Dissertations

The popular Frank-Wolfe (FW) algorithm for solving the network equilibrium problems plays an important role in transportation simulation. Not only has the basic Frank Wolfe algorithm been studied, but also other variations of the FW algorithm (such as Conjugate Frank Wolfe and Bi-Conjugate Frank Wolfe algorithms) have been extensively studied by the research communities.

In this work, the basic Frank Wolfe algorithm is re-visited for the purpose of developing a useful, user-friendly, and appealing Java computer animation for enhancing the teaching effectiveness of this fundamental transportation static network equilibrium algorithm. Since the shortest path (SP) algorithms (such as the well-known …

Analyzing Driver Behavior And Traffic Flow Breakdowns At The Hampton Roads Bridge Tunnel, Michelle L. Allen

Civil & Environmental Engineering Theses & Dissertations

The Hampton Roads Bridge Tunnel (HRBT) is a major link for activity in Hampton Roads. The eastbound direction also suffers from congestion during both morning and peak hours. During these periods of congestion, the flow rate varies in regards to the location of the congestion. This study focuses on investigating driver behavior during these different conditions and briefly investigates the cost of delay due to the different capacities. To accomplish this, per vehicle record data (PVR) is used. This data, collected at the exit of the tunnel, provides information on arrival time, speed, lane location, vehicle class, and time headway. …

Polychlorinated Biphenyl Source Identification In Fish Tissue Using A Multivariate Statistical Evaluation Of Congeners And Stable Isotope Ratio Mass Spectrometry, William Edward Corl Iii

Civil & Environmental Engineering Theses & Dissertations

Polychlorinated biphenyls (PCBs) were commercially produced mixtures primarily utilized as dielectric fluids in the electrical industry. However, due to their stability, they were widely used in many other applications. Although production of PCBs ceased in the 1970's, they continue to be a contaminant in the environment due to their widespread use, their recalcitrant behavior, and their proposed toxicological effects.

In 2008, a routine environmental investigation of an abandoned, concrete-lined pool at a Department of Defense (DoD) training facility in Williamsburg, Virginia led to the discovery of a PCB release from the facility into an adjacent reservoir. A forensic study was …