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Dynamic And Static Effects In Wetting Of Capillaries And Fibers, Taras Andrukh
Dynamic And Static Effects In Wetting Of Capillaries And Fibers, Taras Andrukh
All Dissertations
This research is centered on the analysis of static and dynamic effects of wetting of single capillaries and fibers. We discuss specifics of the capillary rise and drop-on-fiber techniques and develop new methods of characterization of surface energy of single fibers when its contact angle varies between zero and ninety degrees. The contact angles were evaluated and compared for different substrates. We study the dynamics of the meniscus formation inside and outside of capillaries and fibers. We develop a mathematical model of liquid uptake by capillaries and analyze the factors affecting liquid uptake. The derived fundamental equation describes the dynamics …
Induced Elastic Matrix Synthesis Within 3-Dimensional Collagen Constructs, Lavanya Venkataraman
Induced Elastic Matrix Synthesis Within 3-Dimensional Collagen Constructs, Lavanya Venkataraman
All Dissertations
Elastin, a primary component of elastic arteries, maintains structural stability of the cyclically recoiling artery, and critically regulates vascular cell behavior. Accelerated degradation of elastic matrix, such as that seen in vascular pathologies like abdominal aortic aneurysms (AAA), can therefore severely compromise vessel homeostasis. Tissue engineering and in-situ matrix repair strategies evaluated so far are primarily limited in inducing adult vascular cells to replicate the complex elastic matrix assembly process, and restore lost matrix integrity. Previously, our lab established the elastogenic benefits of concurrent delivery of TGF-β1 and HA-oligomers (together termed elastogenic factors, EFs), within 2D cultures of rat aortic …
Phase Transformation In Ti-Mo-O, Herbert Boeckels
Phase Transformation In Ti-Mo-O, Herbert Boeckels
All Dissertations
The present dissertation has investigated the effect of oxygen on the ù and á phase stability in metastable Ti-Mo â titanium alloys using thermal analysis, hardness measurements, electron microscopy, and x-ray diffraction.
Single crystal x-ray diffraction has shown that oxygen atoms are located in the tetrahedral interstitial lattice sites in the rapidly cooled bcc Ti crystal structure, interfering directly with the reversible displacive formation of ù, with this transformation involving collapse of the bcc lattice along â. Subsequent thermal exposure of reversible ù, as occurring during slower cooling, heating, and aging, prompts short range diffusion and the formation of chemical …
Managing Elective And Non-Elective Case Assignments For An Operating Room Suite, Narges Hosseini
Managing Elective And Non-Elective Case Assignments For An Operating Room Suite, Narges Hosseini
All Dissertations
The success of operating room management depends on all levels of decision making, from strategic to tactical and operational decisions. One key decision in systems with block booking is to assign sufficient amount of block time to surgeons and surgery groups. While the typical method of block assignment identifies the share of surgery groups from OR times based on average of past usage, this method does not count for the difference between cost of under and overtime. One of the goals of this research is to develop a decision framework for block assignment. This work is presented in chapter two. …
Synthesis And Characterization Of Nanoscale Fluorescent Polymer Films, Maryus Chyasnavichyus
Synthesis And Characterization Of Nanoscale Fluorescent Polymer Films, Maryus Chyasnavichyus
All Dissertations
Performance of the chemical sensing devices is based sensitivity to the targeted analytes and accuracy of the measurements. Of many different types of chemical sensors, fluorescence based sensing devices draw much attention as efficient yet small and straightforward devices, capable of detection of various analytes at extremely small quantities.
Polymeric materials provide support for the fluorescent materials and usually serve as a host for the chromophores, protecting them from harsh environments, and serve as a transport media for the analyte.
In the present study thin fluorescent polymer films, sensitive to the environment are synthesized and studied. Poly(glycidyl methacrylate) was used …
Photo-Thermal Processing Of Semiconductor Fibers And Thin Films, Nishant Gupta
Photo-Thermal Processing Of Semiconductor Fibers And Thin Films, Nishant Gupta
All Dissertations
Furnace processing and rapid thermal processing (RTP) have been an integral part of several processing steps in semiconductor manufacturing. The performance of RTP techniques can be improved many times by exploiting quantum photo-effects of UV and vacuum ultraviolet (VUV) photons in thermal processing and this technique is known as rapid photo-thermal processing (RPP). As compared to furnace processing and RTP, RPP provides higher diffusion coefficient, lower stress and lower microscopic defects. In this work, a custom designed automated photo assisted processing system was built from individual parts and an incoherent light source. This photo-assisted processing system is used to anneal …
Updated Force Model For Milling Nickel-Based Superalloys, Andrew Henderson
Updated Force Model For Milling Nickel-Based Superalloys, Andrew Henderson
All Dissertations
Nickel-based superalloys are commonly used in applications which require high strength and resistance to creep and oxidation in extreme conditions. All nickel-based superalloys are considered difficult to machine; however, cast gamma-prime-strengthened nickel-based superalloys are more difficult to machine than common nickel-based superalloys. Machining comprises a significant portion of manufacturing processes and with advancements in technology and material properties, the methods and models used must be adapted in order to keep pace.
In this research, correlations are made, using fundamental principles, between measurements made with on-machine touch probes and the cutting tool's wear state, those correlations are used in an adaptive …
Assessment Of Fidelity To Data And Robustness To Uncertainty To Assure Credible Predictions In The Modeling Of Wind Turbine Blades, Kendra Van Buren
Assessment Of Fidelity To Data And Robustness To Uncertainty To Assure Credible Predictions In The Modeling Of Wind Turbine Blades, Kendra Van Buren
All Dissertations
In the field of wind energy, modeling and simulation techniques provide an efficient and economical alternative to experimentation for studying the behavior of wind turbines. Numerical models however are approximations of reality, thusly making it crucial to evaluate various sources of uncertainties that influence the model predictions. Credibility of a numerical model rests on the model's ability to replicate existing experimental data, widely known as fidelity-to-data. This dissertation advocates that fidelity-to-data, while necessary, is insufficient to claim credibility of a numerical model. Herein, the objective is to develop numerical models that not only provide agreement to experimental data, but also …
Supply Chain Network Design: Risk-Averse Vs. Risk-Neutral Decision Making, Alireza Madadi
Supply Chain Network Design: Risk-Averse Vs. Risk-Neutral Decision Making, Alireza Madadi
All Dissertations
Recent events, such as the Heparin tragedy, highlight the necessity for designers and planners of supply chain networks to consider the risk of disruptions in spite of their low probability of occurrence. One effective way to hedge against supply chain network disruptions is to have a robustly designed supply chain network. This involves strategic decisions, such as choosing which markets to serve, which suppliers to source from, the location of plants, the types of facilities to use, and tactical decisions, such as production and capacity allocation. In this dissertation, we focus on models for designing supply chain networks that are …
Develop Novel Frap Techniques For Determining Anisotropic Solute Diffusion In Cartilaginous Tissues, Changcheng Shi
Develop Novel Frap Techniques For Determining Anisotropic Solute Diffusion In Cartilaginous Tissues, Changcheng Shi
All Dissertations
Cartilaginous tissue is a connective tissue composed of specialized cells (e.g., chondrocytes and fibroblasts) that produce a large amount of extracellular matrix (ECM), which is comprised mostly of collagen fibers, abundant ground substance rich in proteoglycan, and elastic fibers. It is characterized by its avascular structures within the tissue, implying that nutrition for normal tissue cells, for maintaining a healthy ECM, is mainly supplied through diffusion from nearby vascularized tissues and synovial fluid. Poor nutritional supply to the cartilaginous tissue is believed to be an important factor leading to tissue degeneration. Moreover, due to the complex collagen fiber structures, the …
Network Traffic Analysis Using Stochastic Grammars, Chen Lu
Network Traffic Analysis Using Stochastic Grammars, Chen Lu
All Dissertations
Network traffic analysis is widely used to infer information from Internet
traffic. This is possible even if the traffic is encrypted. Previous work uses
traffic characteristics, such as port numbers, packet sizes, and frequency,
without looking for more subtle patterns in the network traffic. In this work,
we use stochastic grammars, hidden Markov models (HMMs) and probabilistic
context-free grammars (PCFGs), as pattern recognition tools for traffic
analysis.
HMMs are widely used for pattern recognition and detection. We use a HMM
inference approach. With inferred HMMs, we use confidence intervals (CI) to
detect if a data sequence matches the HMM. To …
Phoneme Weighting And Energy-Based Weighting For Speaker Recognition, Eric Fang
Phoneme Weighting And Energy-Based Weighting For Speaker Recognition, Eric Fang
All Dissertations
This dissertation focuses on determining specific vowel phonemes which work best for speaker identification and speaker verification, and also developing new algorithms to improve speaker identification accuracy. Results from the first part of our research indicate that the vowels /i/, /E/ and /u/ were the ones having the highest recognition scores for both the Gaussian mixture model (GMM) and vector quantization (VQ) methods (at most one classification error). For VQ, /i/, /I/, /e/, /E/ and /@/ had no classification errors. Persons speaking /E/, /o/ and /u/ have been verified well by both GMM and VQ methods in our experiments. For …
Improving Accuracy In Ultra-Wideband Indoor Position Tracking Through Noise Modeling And Augmentation, Salil Banerjee
Improving Accuracy In Ultra-Wideband Indoor Position Tracking Through Noise Modeling And Augmentation, Salil Banerjee
All Dissertations
The goal of this research is to improve the precision in tracking of an ultra-wideband (UWB) based Local Positioning System (LPS). This work is motivated by the approach taken to improve the accuracies in the Global Positioning System (GPS), through noise modeling and augmentation. Since UWB indoor position tracking is accomplished using methods similar to that of the GPS, the same two general approaches can be used to improve accuracy.
Trilateration calculations are affected by errors in distance measurements from the set of fixed points to the object of interest. When these errors are systemic, each distinct set of fixed …
Application Of Carbon Dioxide Towards The Development Of Smart Materials, Green Reaction Schemes And Metallic Nanoparticle Synthesis, Fiaz Mohammed
Application Of Carbon Dioxide Towards The Development Of Smart Materials, Green Reaction Schemes And Metallic Nanoparticle Synthesis, Fiaz Mohammed
All Dissertations
Global carbon dioxide (CO2) emissions have steadily risen over the last 50 years, with 34 billion tons of CO2 released in 2009 alone. Its potential as a greenhouse gas has negatively affected of our lives and environment by the resulting ocean acidification and climate change. To mitigate atmospheric CO2, various strategies have been implemented for CO2 separation, capture, storage and use as a chemical feedstock. The use of CO2 in various chemical industries is attractive as its non-flammable, non-toxic, and relatively inert properties have made it an inherently safer alternative to traditional organic …
Analysis Of Energy Savings Through The Use Of Displacement Ventilation In Domestic Buildings, Patrick Daffin
Analysis Of Energy Savings Through The Use Of Displacement Ventilation In Domestic Buildings, Patrick Daffin
All Theses
This study investigates the conditions under which it might be possible to implement a displacement ventilation system in a residential building. An experimental study of the impact on a mechanical air conditioning system of the vertical location of the inlet and outlet vents was performed. The four ventilation configurations of low inlet high outlet, low inlet low outlet, high inlet high outlet, and high inlet low outlet were compared. These four configurations were compared under 13 different heat load scenarios in a full scale instrumented model room. It was found that, for higher heat loads, the low inlet high outlet …
Environmental And Biological Applications And Implications Of Soft And Condensed Nanomaterials, Pengyu Chen
Environmental And Biological Applications And Implications Of Soft And Condensed Nanomaterials, Pengyu Chen
All Dissertations
Recent innovations and growth of nanotechnology have spurred exciting technological and commercial developments of nanomaterails. Their appealing physical and physicochemical properties offer great opportunities in biological and environmental applications, while in the meantime may compromise human health and environmental sustainability through either unintentional exposure or intentional discharge.
Accordingly, this dissertation exploits the physicochemical behavior of soft dendritic polymers for environmental remediation and condensed nano ZnO tetrapods for biological sensing (Chapter two-four), and further delineate the environmental implications of such nanomaterials using algae- the major constituent of the aquatic food chain-as a model system (Chapter five).
This dissertation is presented as …
A Process Analysis Of Engineering Problem Solving And Assessment Of Problem Solving Skills, Sarah Grigg
A Process Analysis Of Engineering Problem Solving And Assessment Of Problem Solving Skills, Sarah Grigg
All Dissertations
In the engineering profession, one of the most critical skills to possess is accurate and efficient problem solving. Thus, engineering educators should strive to help students develop skills needed to become competent problem solvers. In order to measure the development of skills, it is necessary to assess student performance, identify any deficiencies present in problem solving attempts, and identify trends in performance over time. Through iterative assessment using standard assessment metrics, researchers/instructors are able to track trends in problem solving performance across time, which can serve as a gauge of students' learning gains.
This research endeavor studies the problem solving …
Development Of Feature Recognition Algorithm For Automated Identification Of Duplicate Geometries In Cad Models, Aravind Shanthakumar
Development Of Feature Recognition Algorithm For Automated Identification Of Duplicate Geometries In Cad Models, Aravind Shanthakumar
All Theses
This research presents a feature recognition algorithm for the automated identification of duplicate geometries in the CAD assembly. The duplicate geometry is one of the seven indicators of the lazy parts mass reduction method. The lazy parts method is a light weight engineering method that is used for analyzing parts with the mass reduction potential. The duplicate geometry is defined as any geometries lying equal to or within the threshold distance with the user-defined orientation between them and have the percentage similarity that is equal to or greater than the threshold value. The feature recognition system developed in this research …
Characterization And Restoration Of Historic Rosendale Cement Mortars For The Purpose Of Restoration, Stephanie Hart
Characterization And Restoration Of Historic Rosendale Cement Mortars For The Purpose Of Restoration, Stephanie Hart
All Theses
Mortar was a very common building material in today's historic sites. Before Portland cement was manufactured at a global level, Rosendale cement was commonly used in these mortars. Over time, these mortars in historic sites have begun to break down and wear away. With Rosendale cement in production again, measures can be taken to restore and repair the historic mortars. However, little testing has been done to establish durability of modern Rosendale cement mortars. This presentation highlights the common mix techniques used at the time, and undergoes experiments to establish general properties and predict future durability. Six different mortar mixes …
Concept Generation Using Morphological And Options Matrices, Dani George
Concept Generation Using Morphological And Options Matrices, Dani George
All Theses
The use of morphological matrices as a tool to aid concept generation is examined. Two limitations of the method are highlighted; (1) the large number of potential combinatorial possibilities and (2) the lack of design details in the system concepts generated. An Integrated Idea Generation (IIG) method is proposed to support the generation of detailed system concepts effectively without performing a full factorial combination of the means within a morphological matrix. Pairwise functional combinations are extracted from the functions listed in the morphological matrix and explored in detail using options matrices and innovation challenges, encouraging designers to identify implicit assumptions …
Study Of Cell Viability During Laser Direct Writing Of Cell-Alginate Suspension, Hemanth Gudapati
Study Of Cell Viability During Laser Direct Writing Of Cell-Alginate Suspension, Hemanth Gudapati
All Theses
Laser-assisted cell printing, developed based on Matrix-assisted pulsed-laser evaporation direct-write (MAPLE DW), a typical LIFT (laser-induced forward transfer) practice, has been emerging as one of the most promising biofabrication techniques. Alginate, particularly sodium alginate, is extensively used as the constituent of bioink in laser-assisted cell printing. However, thus far, studies investigating the effect of alginate gelation on cell viability in laser-assisted cell printing are lacking. The objective of this study is to investigate the effects of gelation, gelation time, sodium alginate concentration, and the effect of operating conditions such as the laser fluence on post-transfer cell viability during laser-assisted cell …
Bioswellable Amphiphilic Copolymers, David Ingram
Bioswellable Amphiphilic Copolymers, David Ingram
All Theses
The suture is one of the most commonly used medical devices, consisting of a fiber, a surgical needle and the packaging in which it is stored. The fiber itself remains after implantation for a defined time and is responsible for the approximation of the wound during the healing process. The needle merely serves to aid in insertion, and preferably has a diameter larger than the diameter of the fiber .
The 1970's marked the birth of a new family of fibrous materials for the approximation of wounds: synthetic absorbable sutures. This family has the ability to provide wound support during …
Investigation Of Auxiliary Winding Harmonic Resonance Phenomena In Single Phase Induction Motors, Gaurav Singh
Investigation Of Auxiliary Winding Harmonic Resonance Phenomena In Single Phase Induction Motors, Gaurav Singh
All Theses
In recent years, the proliferation of single phase power electronics based loads has given rise to a number of power quality issues in the power grid. Harmonics in voltage and current waveforms are one of the biggest problems in this family of power quality issues. Until some years back, power system utilities did not consider harmonics due to small single phase loads to be a big problem. In fact, only large loads were considered as potential hotspots for power quality problems. However, the advent of compact fluorescent lamps (CFLs), personal computers and consumer electronic devices, which utilize rectifier front ends, …
Reverse Osmosis Desalination With Integrated Compressed Air Energy Storage: Conceptual Design And Modeling, Pooja Mahajan
Reverse Osmosis Desalination With Integrated Compressed Air Energy Storage: Conceptual Design And Modeling, Pooja Mahajan
All Theses
Growing fresh water needs have led to an interest in water desalination using reverse osmosis (RO) membranes. Energy consumption has a large share in the expenses incurred to drive a reverse osmosis desalination system. With depleting fossil fuel reserves, tapping renewable sources of energy is a promising alternative to meet the energy requirements. Wind power coupled to an RO desalination system is a potential means of delivering clean water using sustainable energy. This work investigates modeling of a conceptual wind-energy-driven RO desalination system that is made possible because of an air-pressure energy storage mechanism. Bench-scale experiments were performed on an …
Preliminary Investigation Into The Design Of Thermally Responsive Forster Resonance Energy Transfer Colloids, Monte Bedford
Preliminary Investigation Into The Design Of Thermally Responsive Forster Resonance Energy Transfer Colloids, Monte Bedford
All Theses
While nuclear imaging techniques (Magnetic Resonance Imaging, Computed Tomography, and Positron Emission Tomography) have proven effective for diagnosis and treatment of disease in the human body, fluorescence-enhanced optical imaging offers additional benefits. Fluorescent imaging provides high resolution with real-time response, persistent lifetime (hours to days), cell targeting, and transdermal penetration with minimal physical encumbrance. Malignant cells can be targeted by absorbance of exogenous fluorescent nanoprobe contrast agents. Imaging is improved by fluorescent enhancement, especially by energy transfer between attached dyes. Also for use against cancer are heat-active treatments, such as hyperthermal, photothermal, and chemothermal therapies. Helpful to these treatments is …
Analysis And Evaluation Of Existing And Novel Turbulent Dynamic Pressure Based Methods For Measuring Bridge Pier And Abutment Scour, Murray Fisher
Analysis And Evaluation Of Existing And Novel Turbulent Dynamic Pressure Based Methods For Measuring Bridge Pier And Abutment Scour, Murray Fisher
All Dissertations
Scour is one of the most significant threats to bridge infrastructure and is the leading cause of failure within the United States. Given this risk to the nation’s transportation infrastructure, it is necessary to understand the development of scour holes around bridge piers and abutments. This can be achieved with scour monitoring, a Federal Highway Administration approved scour countermeasure. As the monitoring techniques available range from simple devices that rest on or in the channel bed to advanced scanning systems that provide a bed contour profile, a concise study of the state of the art in real time scour measurement …
Towards Trustworthy, Efficient And Scalable Distributed Wireless Systems, Ze Li
Towards Trustworthy, Efficient And Scalable Distributed Wireless Systems, Ze Li
All Dissertations
Advances in wireless technologies have enabled distributed mobile devices to connect with each other to form distributed wireless systems. Due to the absence of infrastructure, distributed wireless systems require node cooperation in multi-hop routing. However, the openness and decentralized nature of distributed wireless systems where each node labors under a resource constraint introduces three challenges: (1) cooperation incentives that effectively encourage nodes to offer services and thwart the intentions of selfish and malicious nodes, (2) cooperation incentives that are efficient to deploy, use and maintain, and (3) routing to efficiently deliver messages with less overhead and lower delay. While most …
Integrated Production And Distribution Problem With Single Perishable Product, Wennian Li
Integrated Production And Distribution Problem With Single Perishable Product, Wennian Li
All Dissertations
This dissertation investigated the extension of the Integrated Production and Distribution Scheduling Problem (IPDSPP) using a variety of perishable products, applying the JIP principle and make-to-order strategy to integrate the production and distribution schedules. A single perishable product with a constant lifetime after production was used in the model discussed here. The objective of the problem was to find the solution that results in minimal system total transportation costs while satisfying customer demand within a fixed time horizon. In the solution, the fleet size, vehicle route and distribution schedule, plant production batch size and schedule were determined simultaneously. This research …
Stochastic Tools For Network Security: Anonymity Protocol Analysis And Network Intrusion Detection, Lu Yu
Stochastic Tools For Network Security: Anonymity Protocol Analysis And Network Intrusion Detection, Lu Yu
All Dissertations
With the rapid development of Internet and the sharp increase of network crime, network security has become very important and received a lot of attention.
In this dissertation, we model security issues as stochastic systems. This allows us to find weaknesses in existing security systems and propose new solutions. Exploring the vulnerabilities of existing security tools can prevent cyber-attacks from taking advantages of the system weaknesses. We consider The Onion Router (Tor), which is one of the most popular anonymity systems in use today, and show how to detect a protocol tunnelled through Tor. A hidden Markov model (HMM) is …
Network Target Coordination For Design Optimization Of Decomposed Systems, Wenshan Wang
Network Target Coordination For Design Optimization Of Decomposed Systems, Wenshan Wang
All Dissertations
A complex engineered system is often decomposed into a number of different subsystems that interact on one another and together produce results not obtainable by the subsystems alone. Effective coordination of the interdependencies shared among these subsystems is critical to fulfill the stakeholder expectations and technical requirements of the original system. The past research has shown that various coordination methods obtain different solution accuracies and exhibit different computational efficiencies when solving a decomposed system. Addressing these coordination decisions may lead to improved complex system design. This dissertation studies coordination methods through two types of decomposition structures, hierarchical, and nonhierarchical.
For …