Engineering Commons^™

Evaluation Of Environmental Materials As Thermal Witness Materials, Shashank Vummidi Lakshman

Dissertations

New and complex energetic materials are under development for achieving tunable pyrotechnical events for applications such as neutralization of biological weapons, bunker busters and many others. To guide the development of hybrid materials, the pyrotechnical environment they produce requires higher degree of characterization i.e. good description of spatial and temporal temperature distribution.

Temperature measurements in pyrotechnical events are especially challenging, where the temperature of the environment rises more than 2000 K on microseconds to few milliseconds time scale. These environments produce high thermal stress where traditional sensors like thermocouples, optical pyrometers struggle to describe the dynamic changes in the environment. …

Synthesis And Characterization Of Metal-Based Reactive Powders, Yasmine Aly

Dissertations

Aluminum added to propellants, explosives, and pyrotechnics, boosts their energy density. Different approaches were investigated that could shorten aluminum ignition delays, increase combustion rates, and decrease the tendency of aluminum droplets to agglomerate. Here, Al-based reactive, mechanically milled materials are prepared and characterized.

For powders with Fe, Ni, or Zn additives, the particles consist of an aluminum matrix and inclusions of Fe, Ni, or Zn comprising 10 at % of the bulk composition. For additives of Ni and Zn, only short milling times can be used to prepare composites; intermetallic phases form at longer milling times. Thermogravimetric analysis shows selective …

Novel Scrubbing Systems For Post-Combustion Co2 Capture And Recovery, Tripura Mulukutla

Dissertations

Power plant emissions of flue gas releases considerable CO₂ to the atmosphere; CO₂ is considered to be the main contributor to global warming. Several gas absorption techniques are being investigated to reduce the capital and operating costs for CO₂ capture from post-combustion flue gas. Conventional method of CO₂ capture by an aqueous solution of monoethanolamine (MEA) and its subsequent stripping in a separate tower with steam at 120°C, is a highly energy intensive process. The low partial pressure of CO₂ in the flue gas inhibits the application of CO₂-selective membranes unless methods are …

Ignition Mechanism In Nanocomposites Thermites, Rayon Williams

Dissertations

Nanocomposite thermites (n-thermites) have been actively investigated for a wide range of potential applications including propellants, explosives, and pyrotechnics. There have been several recent efforts aimed at understanding ignition mechanisms of nanocomposite reactive materials. Although significant progress has been made, ignition mechanisms remain elusive. At the same time, a robust ignition model is required to incorporate these materials in practical energetic formulations. A challenge of this effort is to describe the mechanisms of ignition of n-thermites prepared by Arrested Reactive Milling (ARM) with different stimuli, including heat, spark and impact and also develop a multi-step kinetic model describing different processes …

Gas-Solid Transport And Reaction Via Intervened Evaporating Sprays, Pengfei He

Dissertations

Fluid catalytic cracking (FCC) is a major process used for converting heavy oils to transportation fuels and light olefins. The gas-solid transport with reaction via intervened evaporating sprays in the FCC riser is specially important but complicated, with coupled mechanisms of chemical reaction and heat, momentum and mass transfer among multiple phases (liquid, solid and gas) in the restriction of wall boundary. Recent developments in FCC process models have progressed along two lines. One aims to develop composition-based kinetic models derived from molecular characterization of petroleum fractions while overlooking the hydrodynamic effect on local catalyst to oil ratio (CTO). The …

Kinetic Analysis Of Thiol Oxidation To Study The Effects Of Fluorinated Groups On Metal Phthalocyanine Catalysts, Nellone Eze Reid

Dissertations

The oxidation of thiol (RSH) to disulfide (RSSR) is important biologically and industrially. Corrosive and malodorous thiols exist as contaminants in wastewater discharge from mining facilities, pulp and paper mills, tanneries, and oil refineries. The elimination of thiols from petroleum products is necessary for even cleaner fuels. Thiols in gas products can also inhibit catalyst activity for some downstream processes.

Experiments and mechanistic kinetic studies were conducted for the aerobic oxidation of 2-mercaptoethanol (2-ME) and 4-fluorobenzenethiol (4-FBT) catalyzed by cobalt phthalocyanines: H₁₆PcCo, F₁₆PcCo, and F₆₄PcCo, each exhibiting a metal center subject to increasing Lewis …

Global Optimization Methods For Localization In Compressive Sensing, Marco Rossi

Dissertations

The dissertation discusses compressive sensing and its applications to localization in multiple-input multiple-output (MIMO) radars. Compressive sensing is a paradigm at the intersection between signal processing and optimization. It advocates the sensing of “sparse” signals (i.e., represented using just a few terms from a basis expansion) by using a sampling rate much lower than that required by the Nyquist-Shannon sampling theorem (i.e., twice the highest frequency present in the signal of interest). Low-rate sampling reduces implementation’s constraints and translates into cost savings due to fewer measurements required. This is particularly true in localization applications when the number of measurements is …

Optimization Of Vehicle Routing And Scheduling With Travel Time Variability - Application In Winter Road Maintenance, Haifeng Yu

Dissertations

This study developed a mathematical model for optimizing vehicle routing and scheduling, which can be used to collect travel time information, and also to perform winter road maintenance operations (e.g., salting, plowing). The objective of this research was to minimize the total vehicle travel time to complete a given set of service tasks, subject to resource constraints (e.g., truck capacity, fleet size) and operational constraints (e.g., service time windows, service time limit).

The nature of the problem is to design vehicle routes and schedules to perform the required service on predetermined road segments, which can be interpreted as an arc …

Characterizing Motor Control Signals In The Spinal Cord, Yi Guo

Dissertations

The main goal of this project is to develop a rodent model to study the central command signals generated in the brain and spinal cord for the control of motor function in the forearms. The nature of the central command signal has been debated for many decades with only limited progress. This thesis presents a project that investigated this problem using novel techniques. Rats are instrumented to record the control signals in their spinal cord while they are performing lever press task they are trained in. A haptic interface and wireless neural data amplifier system simultaneously collects dynamic and neural …

Congestion Control, Energy Efficiency And Virtual Machine Placement For Data Centers, Yan Zhang

Dissertations

Data centers, facilities with communications network equipment and servers for data processing and/or storage, are prevalent and essential to provide a myriad of services and applications for various private, non-profit, and government systems, and they also form the foundation of cloud computing, which is transforming the technological landscape of the Internet. With rapid deployment of modern high-speed low-latency large-scale data centers, many issues have emerged in data centers, such as data center architecture design, congestion control, energy efficiency, virtual machine placement, and load balancing.

The objective of this thesis is multi-fold. First, an enhanced Quantized Congestion Notification (QCN) congestion notification …

Physical Controls On Water Flow And Solute Transport In Coastal Aquifers, Xiaolong Geng

Dissertations

Groundwater flow and associated subsurface solute fates have a significant impact on the structure and productivity of near-shore coastal ecosystems. For proper assessment and management of these coastal groundwater resources, it is quite essential to investigate the key factors (tides, waves, evaporation, and freshwater recharge etc.) affecting coastal groundwater systems. The main objective of this study is to examine and quantify two important physical control factors, oceanic waves and evaporation, on the groundwater flow and solute transport in near-shore aquifers. For the investigation of wave effects, a Computational Fluid Dynamics (CFD) modeling tool, Fluent, is used to simulate wave- induced …

Field Methods For Rapidly Characterizing Contaminant Mobility In Paint Waste During Bridge Rehabilitation, Zhan Shu

Dissertations

Currently, the New York State Department of Transportation (NYSDOT) uses a conservative approach of classifying all paint waste as hazardous from bridges undergoing rehabilitation which were constructed before 1989. This practice stems from the fact that there is no approved reliable, fast, and efficient method for classifying paint waste in-situ as non-hazardous. The main objective of this study was to develop a model that can predict the leachability of trace metals in paint waste generated during bridge rehabilitation. A statistically significant number of bridge sites were sampled based on hypothesis testing. Samples were then evaluated for total concentration of Resource …

Modeling, Control And Simulation Of Control-Affine Nonlinear Systems With State-Dependent Transfer Functions, Roger Kobla Kwadzogah

Dissertations

There has been no known research that applies nonlinear transfer function to a nonlinear control problem. The belief is that nonlinear systems have no transfer functions. The Laplace transformation required to define transfer functions is not tractable mathematically when the coefficients of the differential equation are functions of state, output and control variables. In other words, it is not defined for systems that do not obey principles of superposition. Only linear systems obey this principle. Therefore, this dissertation work represents the very first research to demonstrate how transfer functions can be used to represent and design feedback control for nonlinear …

Dynamics Of 1d Granular Column, Luo Zuo

Dissertations

This dissertation is focused on a discrete element study of the dynamics of a one- dimensional column of inelastic spheres that it subjected to taps by prescribing a half sine wave pulse to supporting floor. Contact interactions obey the Walton-Braun soft-sphere model in which the loading (unloading) path is governing by linear springs of stiffness K1, thereby producing col lisional energy loss through a constant restitution coefficient e. Over a ‘short time scale’, computations are done to examine the floor pulse wave as it propagates through the column contact network. Comparisons of the simulated findings are made with experimental measurements …

Rate Alterable Traumatic Brain Injury Device For Rodent Models, Radia Abdul Wahab

Dissertations

Traumatic Brain Injury (TBI) is a physical impact to the head resulting in functional deficits in memory and motor systems. TBI is a prevalent problem occurring in 1.7 million people annually in the United States (Faul et al. 2010). TBIs can differ greatly in terms of the biomechanics of the impact such as magnitude, direction and rate. Indeed, it is likely that the wide range of TBI outcomes may be due to the physical characteristics of the trauma. Studies to date on impact have used injury devices with limited alterable parameters. Therefore, the existing impact studies have considered the effect …

The Effect Of Mechanical Vestibular Stimulation On Muscle Tone And Spasticity In Individuals With Neurological Impairment, Ghaith J. Androwis

Dissertations

In the desire to better understand spasticity mainly in Cerebral Palsy (CP) and to examine vestibular stimulation as a future intervention for .muscle tone reduction, and to be able to describe the change in level of spasticity in subjects with disability and describe interventions effects, a series of experiments are done on children with spasticity. In addition to understanding the otoliths in the vestibular system and their projections, properties and pathways a more important major objective of this work is to validate the changes in otoliths signal caused by vestibular stimulation based on the Equilibrium Point Hypothesis and the inclusion …

Analyses Of Groundwater Contribution To A Riverine Wetland, Farzad Mahmoodinobar

Dissertations

Rainfall, runoff, overbank flow and groundwater, all contribute water to wetlands. Each transport element is associated with unique modeling approaches and uncertainties. Transpiration is perhaps the hardest to quantify as it is subject to all the variability of plant growth. Transpiration causes land area to lose moisture and the loss amount depends on precipitation incidence, the temperature and type and extent of vegetation. Plants can intercept virtually all recharge during the growing season and almost none from late fall to early spring in northeastern United States. Thus, an improvement in the transpiration element can contribute considerably to an improved groundwater …

Discrete Element Method Based Scale-Up Model For Material Synthesis Using Ball Milling, Priya Radhi Santhanam

Dissertations

Mechanical milling is a widely used technique for powder processing in various areas. In this work, a scale-up model for describing this ball milling process is developed. The thesis is a combination of experimental and modeling efforts.

Initially, Discrete Element Model (DEM) is used to describe energy transfer from milling tools to the milled powder for shaker, planetary, and attritor mills. The rolling and static friction coefficients are determined experimentally. Computations predict a quasi- steady rate of energy dissipation, Ed, for each experimental configuration. It is proposed that the milling dose defined as a product of Ed and milling …

Construction And Assessment Of A Computer Graphics-Based Model For Wheelchair Propulsion, Brooke Marie Odle

Dissertations

Upper limb overuse injuries are common in manual wheelchair using persons with spinal cord injury (SCI), especially those with tetraplegia. Biomechanical analyses involving kinetics, kinematics, and muscle mechanics provide an opportunity to identify modifiable risk factors associated with wheelchair propulsion and upper limb overuse injuries that may be used toward developing prevention and treatment interventions. However, these analyses are limited because they cannot estimate muscle forces in vivo. Patient-specific computer graphics-based models have enhanced biomechanical analyses by determining in vivo estimates of shoulder muscle and joint contact forces. Current models do not include deep shoulder muscles. Also, patient-specific models …

Extracting Product Development Intelligence From Web Reviews, Ismail Artun Yagci

Dissertations

Product development managers are constantly challenged to learn what the consumer product experience really is, and to learn specifically how the product is performing in the field. Traditionally, they have utilized methods such as prototype testing, customer quality monitoring instruments, field testing methods with sample customers, and independent assessment companies. These methods are limited in that (i) the number of customer evaluations is small, and (ii) the methods are driven by a restrictive structured format. Today the web has created a new source of product intelligence; these are unsolicited reviews from actual product users that are posted across hundreds of …

Influence Of Beach Hydrodynamics On Saltwater Transport And Oil Persistence In Beaches, Ali Abdollahi-Nasab

Dissertations

The exchange of water and solutes across the aquifer-ocean interface plays an important ecological role in both aquifer and the open water. Saltwater intrusion could prevent utilization of groundwater for either drinking water or irrigation. In addition, the flux of solutes, such as nutrients, from inland groundwater sources plays an important role in shoreline ecology, especially in embayments. This research relies on a three-pronged approach, involving a laboratory beach experiment, field scale experiments and numerical analyses. The laboratory beach experiment is designed to investigate the fundamental processes occurring in beach aquifers. It explores the effects of buoyancy (or lack thereof) …

Performance Analysis And Scheduling Strategies For Ambulatory Surgical Facilities, Xuanqi Zhang

Dissertations

Ambulatory surgery is a procedure that does not require an overnight hospital stay and is cost effective and efficient. The goal of this research is to develop an ASF operational model which allows management to make key decisions. This research develops and utilizes the simulation software ARENA based model to accommodate: (a) Time related uncertainties – Three system uncertainties characterize the problem (ii) Surgery time variance (ii) Physician arrival delay and (iii) Patient arrival delay; (b) Resource Capture Complexities – Patient flows vary significantly and capture/utilize both staffing and/or physical resources at different points and varying levels; and (c) Processing …

Computational Optimization Methods For Modeling The Effect Of Muscle Forces On Bone Strength Adaptation, Catherine Siena Florio

Dissertations

An improved understanding of the mechanical influences that alter the strength of a bone can aid in the refinement of the wide array of currently available techniques to counteract the losses of bone strength that occur due to age or disuse both on Earth and in Space. To address this need, computational modeling methods to quantitatively analyze and compare the effects of mechanical factors on the strength of a targeted bone within a multibone, multimuscle system are developed and implemented in this work. Through a more detailed representation of the system in which the bone acts and the creation of …