Digital Commons Network^™

Computational Methods For Two-Phase Flow With Soluble Surfactant, Kuan Xu

Dissertations

A mathematical model is formulated and solved for the two-phase flow of a viscous drop or inviscid bubble in an immiscible, viscous surrounding fluid in the zero Reynold's number or Stokes flow limit. A surfactant that is present on the interface is also soluble in the exterior fluid, and the drop is deformed by an imposed linear flow. The geometry is two-dimensional and Cartesian.

The dissolved surfactant is considered in the physically realistic limit of large bulk Péclet number. That is, it convects and diffuses as a passive scalar in the bulk flow where the ratio of its convection to …

Natural Selection On Mrna Secondary Structure And Its Correlation With Protein Functional Groups, Suresh Solaimuthu

Dissertations

Natural selection may occur at multiple levels of the biological hierarchy, including at the molecular level. It may occur on any phenotypic trait that evidences variation and that is heritable. This research uses computational methods to investigate whether the stability of the secondary structures of mRNAs has been the subject of natural selection.

The DNA sequence that codes for a particular target protein is only partially determined by that protein, since the redundancy of the genetic code permits multiple possible synonymous codons for each peptide. An RNA transcript of a DNA protein template (gene) folds back on itself through complementary …

Design Of Novel Drug Delivery System And Optimal Dosage Regimens, Kwang Seok Kim

Dissertations

Three representative drug delivery systems were analyzed to emphasize the roles of mathematical models and computer-aided simulations in pharmaceutical research. In the first project, a protocol was developed so that the optimal regimen, consisting of the intravenous boluses and subsequent infusion of theophylline, could be obtained once information on the pharmacokinetics became available. The method was based on a two-compartment model of the human body. A module was created and posted on a website for free access. The second project dealt with the transdermal heat-assisted delivery of corticosterone. Heat conduction and drug diffusion through the patch and the skin were …

Study Of Magnetic Helicity In Solar Active Regions And Its Relationship With Solar Eruptions, Sung-Hong Park

Dissertations

It is generally believed that eruptive phenomena in the solar atmosphere such as solar flares and coronal mass ejections (CMEs) occur in solar active regions with complex magnetic structures. The magnetic complexity is quantified in terms of twists, kinks, and interlinkages of magnetic field lines. Magnetic helicity has been recognized as a useful measure for these properties of a given magnetic field system. Magnetic helicity studies have been naturally directed to the energy buildup and instability leading to solar eruptions. However, in spite of many years of study, detailed aspects of initiation mechanisms of eruptive events are still not well …

Atomic And Electronic Structure Studies Of Nano-Structured Systems : Carbon And Related Materials, Sumit Saxena

Dissertations

Modeling in the framework of density functional theory has been conducted on carbon nanotubes and graphene nano-structures. The results have been extended to non-carbon systems such as boron nanostructures. Computational studies are complemented by experimental methods to refine the structural models and obtain a better understanding of the electronic structure.

It is observed that the zigzag edged bilayered graphene nanoribbons are highly unstable as compared to their armchair counterparts. A novel approach has been proposed for the patterning of chirality/diameter controlled single walled carbon nanotubes. Nanotube formation is found to be assisted by edge ripples along with the intrinsic edge …

A Numerical Study On The Propagation And Interaction Of Strongly Nonlinear Solitary Waves, Qiyi Zhou

Dissertations

We study numerically a strongly nonlinear long wave model for surface gravity waves propagating in both one and two horizontal dimensions. This model often referred to as the Su-Gardner or Green-Naghdi equations can be derived from the Euler equations under the assumption that the ratio between the characteristic wavelength and water depth is small, but no assumption on the wave amplitude is required. We first generalize the model to describe large amplitude one-dimensional solitary waves in the presence of background shear of constant vorticity. After computing the solitary wave solution of the strongly nonlinear model, the interaction between two solitary …

The Public Understanding Of Climate Change : A Case Study Of Taiwanese Youth, Shih-Yun Kuo

Dissertations

Global climate change is likely to be the most challenging environmental dilemma of the 21st century because its impacts on ecosystems and human society are transnational in scale and long term in scope. Due to its high scientific complexity and uncertainty and high political and economic sensitivity, mitigating the problem will require interdisciplinary cooperation and collective and sustained efforts on the part of all nations. Sufficient domestic support from both government and the lay public will not only be significant to the success of an international climate regime, but also crucial to the effectiveness of potential domestic climate policies.

Such …

Synoptic Variability Of A Cir-Driven Open-Closed Boundary During Solar Minimum, Kevin Urban

Theses

The year 2008 marked a historically quiet period of solar activity during the declining phase of solar cycle 23. Such quiet time has permitted researchers to clearly distinguish the spectral signature of a corotating interaction region’s (CIR) impact on the open-closed boundary (OCB) of the magnetosphere in the southern hemisphere’s auroral zone. By using the PENGUIn AGOs network of ground-based magnetometers on the Antarctic continent, the synoptic behavior of the OCB during a CIR-driven magnetic storm has been studied. Observations were compared with results provided by the BATSRUS space weather model. It is shown that such synoptic magnetometer data sets …

Motor Data Scaling By Respiration Frequencies In Rest, Amit Madhukar Kamble

Theses

Functional Magnetic Resonance Imaging (fMRI) is widely used as a tool to see activations in the different brain regions. Motor data acquired from fMRI scan is accompanied with signal due to hemodynamic changes taking place during the scan. This hemodynamic signal is dominated by parameter alteration in the large vessels of brain. Scaling of task induced BOLD signal with hypercapnic or breathold data is one of the effective methods to minimize the signal due to large vessels. Patient discomfort and compliance has been a major issue with these methods hence in this study we used respiration frequencies in rest data …

A Haptic Control System For Functional Electrical Stimulation Of Paraplegic Legs, Mark R. Shaker

Theses

Functional electrical stimulation (FES) is a means by which paraplegic men and women can use their natural legs for walking. In FES the impaired muscles are stimulated with electricity in a proper cycle to cause the legs to move in a walking pattern. It can be greatly beneficial for paraplegics however, current systems are not widely used because they are difficult to control in a useful manner.

The system proposed here uses a haptic interface, one that utilizes the sense of touch, attached to a user’s index and middle fingers. The haptic device allows the wearer to feel with the …

Variance Reduction Techniques For Estimating Quantiles And Value-At-Risk, Fang Chu

Dissertations

Quantiles, as a performance measure, arise in many practical contexts. In finance, quantiles are called values-at-risk (VARs), and they are widely used in the financial industry to measure portfolio risk. When the cumulative distribution function is unknown, the quantile can not be computed exactly and must be estimated. In addition to computing a point estimate for the quantile, it is important to also provide a confidence interval for the quantile as a way of indicating the error in the estimate. A problem with crude Monte Carlo is that the resulting confidence interval may be large, which is often the case …

Hardware Support For Real-Time Network Security And Packet Classification Using Field Programmable Gate Arrays, Nitesh Bhicu Guinde

Dissertations

Deep packet inspection and packet classification are the most computationally expensive operations in a Network Intrusion Detection (NID) system. Deep packet inspection involves content matching where the payload of the incoming packets is matched against a set of signatures in the database. Packet classification involves inspection of the packet header fields and is basically a multi-dimensional matching problem. Any matching in software is very slow in comparison to current network speeds. Also, both of these problems need a solution which is scalable and can work at high speeds. Due to the high complexity of these matching problems, only Field-Programmable Gate …

Properties And Device Applications Of Silicon And Silicon-Germanium Nanostructures With Different Dimensions, Han-Yun Chang

Dissertations

Defect-free crystalline Si/SiGe(Ge) nanostructures are demonstrated despite the 4% lattice mismatch between Si and Ge. The lattice mismatch-induced strain is sufficiently relaxed through the designed, cluster morphology, or nanowire (NW) structures. Future device applications of these nano structures require complete understanding of their structural, optical, electrical and thermal properties. This study explores these properties in two-dimensional (2D) Si/Si:B delta-doped multilayers, 2D Si/Si_1-xGe_x planar multilayers, three-dimensional (3D) Si/Si_1-xGe_{x cluster multilayers, one-dimensional (1D) Si NWs and 1D Si/Ge NW heterojunctions (HJs).}

Raman scattering and photoluminescence measurements show that by alternating heavily boron-doped layers with layers of …

The Floating Contract Between Risk-Averse Supply Chain Partners In A Volatile Commodity Price Environment, Mojisola Kike Otegbeye

Dissertations

In this dissertation, two separate but closely related decision making problems in environments of volatile commodity prices are addressed. In the first problem, a risk-averse commodity user's purchasing policy and his risk-neutral supplier's pricing decision, where the user can purchase his needs through contract with his supplier as well as directly from the spot market, are analyzed. The commodity user is assumed to be the supplier's sole client, and the supplier can always expand capacity, at a cost to the user, to accommodate the user's demand in excess of initially reserved capacity.

In the more generalized second problem, both parties …

Novel Micron- And Nano-Scale Energetic Materials For Advanced Gun Propulsion, Their Material Properties, And Their Effects On Ballistic Performance, Thelma Gatuz Manning

Dissertations

This dissertation focused on the investigation of novel materials that are both energetic and inert in their micron- and nano-scale crystalline form. The characterization of the materials properties and its effects on the ballistic performance when incorporated into a composite material were evaluated as a gun propellant for application in a future weapon system for the US Army. Some of these materials may find dual use in civilian applications. Applications in small and medium arms, artillery, tank, aircraft, and shipboard gun systems will all benefit from these advancements. Not only will gun system performance be improved for greater stand-off range …

New Data Structures, Models, And Algorithms For Real-Time Resource Management, Xinfa Hu

Dissertations

Real-time resource management is the core and critical task in real-time systems. This dissertation explores new data structures, models, and algorithms for real-time resource management.

At first, novel data structures, i.e., a class of Testing Interval Trees (TITs), are proposed to help build efficient scheduling modules in real-time systems. With a general data structure, i.e., the TIT* tree, the average costs of the schedulability tests in a wide variety of real-time systems can be reduced. With the Testing Interval Tree for Vacancy analysis (TIT-V), the complexities of the schedulability tests in a class of parallel/distributed real-time systems can be effectively …

Constitutive Modeling Of Glassy Memory Polymers, Mahesh Khanolkar

Dissertations

The aim of this research is to develop constitutive models for non-linear materials. Here, issues related for developing constitutive model for glassy shape memory polymers are addressed in detail. Shape memory polymers are novel material that can be easily formed into complex shapes, retaining memory of their original shape even after undergoing large deformations. The temporary shape is stable and return to the original shape is triggered by a suitable mechanism such heating the polymer above a transition temperature. Glassy shape memory polymers are called glassy because the temporary shape is fixed by the formation of a glassy solid, while …

Transport Mechanisms And Modeling Of Riser Reactor, Dawei Wang

Dissertations

Riser reactors are extensively employed in various industrial applications. In a riser reactor, the hydrodynamics is closely interacted with kinetic reactions. Common models for the performance prediction of riser reactors overlook this vital coupling effect, which not only miss the important reaction characteristics in the dense-phase transport regime of riser reactors but also misinterpret the kinetic properties via ad hoc adjustments. It is noted that the modeling of hydrodynamics in riser flows has major flaws in its predictability of phase transport in both dense-phase and accelerating regimes where most reactions occur. In addition, with the spray feeding of reactants at …

Modeling With Bivariate Geometric Distributions, Jing Li

Dissertations

This dissertation studied systems with several components which were subject to different types of failures. Systems with two components having frequency counts in the domain of positive integers, and the survival time of each component following geometric or mixture geometric distribution can be classified into this category. Examples of such systems include twin engines of an airplane and the paired organs in a human body. It was found that such a system, using conditional arguments, can be characterized as multivariate geometric distributions. It was proved that these characterizations of the geometric models can be achieved using conditional probabilities, conditional failure …

Formation Of Screen-Printed Contacts On Multicrystalline Silicon (Mc-Si) Solar Cells, Vishal R. Mehta

Dissertations

Commercial multicrystalline silicon (me-Si) solar cells use screen-printing process for depositing both the Ag paste based gridded front and Al based back (whole area) metal contacts.. This thesis relates to experimental and theoretical studies of contact formation mechanisms in silicon solar cells. Temperature distribution studies during optical processing by. attached thermocouples to cells indicates that the maximum temperature reached under the front silver metal is less. than 800°C; this is lower than the eutectic point of Ag-Si (≈835°C). An analysis of the interaction of Ag particles and Si via the constituents of glass is given. This mechanism leaches metallic ions …

Multi-Component Boron Coatings On Low Carbon Steel Aisi 1018, Naruemon Suwattananont

Dissertations

Boronizing and metalizing are thermo-chemical surface hardening treatments in which boron and metal atoms diffuse into the metal substrate forming metallic boride layers, providing complex properties of B-Me-Fe system.

To study multi-component boron coatings on low carbon steel AISI 1018, the simultaneous powder pack method of boronizing and metalizing was selected to perform the coatings. One B-Fe system and eight boron-metal (B-Me-Fe) systems from transition metals group IVB (Ti, Zr, Hf), group VB (Nb, Ta), and group VIB (Cr, Mo, W) were studied. The system specimens were thermo-chemically treated at 950°C for 4 hours in a crucible containing powder mixture …

Optimizing Integrated Service For A Transit Route With Heterogeneous Demand, Yavuz Yusuf Ulusoy

Dissertations

The methodology developed in this dissertation attempts to optimize integrated service that minimizes the total cost, including user and supplier costs, of a transit route with heterogeneous demand. While minimizing total cost, a set of practical constraints, such as capacity, operable fleet size and frequency conservation, are considered.

The research problem is presented in three scenarios, consisting of various service patterns (e.g., all-stop, short-turn and express) under heterogeneous demand. A logit-based model was used to estimate passenger transfer demand. An exhaustive search method was developed to find the optimal solutions for a simplified transit route with six stops, and a …

Mechanisms For Quality-Of-Service Provisioning In Networks With Extended Services, Zhen Qin

Dissertations

The emerging network traffic with various Quality-of-Service (QoS) requirements creates a demand for QoS service provisioning beyond the best effort service that Internet currently provides. QoS provisioning requires a framework that satisfies users' QoS and cost demand while maximizes benefits for network service providers. It is considered that QoS provisioning involves three issues: a) estimations of the network QoS performance, which can be achieved by performing network measurement; b) dissemination of the measured QoS states throughout the network with states exchanged among different network routers; and c) QoS routing. In this dissertation, these three issues are addressed.

In QoS networks, …

Experiences Of Pregnancy, Childbirth And Post-Partem Period In Urban And Suburban Immigrant Pakistani Women, Rubab I. Qureshi

Dissertations

A body of research suggests that immigrants arrive in the U.S. in good health, a healthy immigrant effect. As immigrants acculturate and absorb dominant cultural norms (measured by proxy variables such as language preference, employment, smoking and alcohol consumption), their health status deteriorates. There is a need to understand how immigrants adapt to a changed social and cultural environment and how this may influence health.

A study of pregnancy, childbirth and the postpartum period in immigrant Pakistani women living in New Jersey explored the interface of culture, immigration and health. The study employed a three pronged approach. Census data were …

Coupled Simulation Of Loading And Response Of Columns Under Extreme Events, Navid H. Allahverdi

Dissertations

Forces imparted to structural columns during blast-induced loading depends on the shape and size of columns as well as on the intensity of the blast. Column's geometry - i.e., shape and size - influences the flow field around the column and consequently the flow field determines forces experienced by the column The main objective of this research is to estimate the forces imparted to columns in a blast event through studying the air flow field around columns

In this study, the physics of shock wave reflection and rarefaction waves are reviewed with application to describing the air flow around columns …

Noxious Odor In Residential Environments : Coping In Reactive And Proactive Ways In Three New Jersey Communities, Maria Beatriz Yabur

Dissertations

Currently little is known about the effects of noxious odor on people's daily lives. This lack of knowledge is apparent in the rules and regulations concerning odor. This dissertation addresses this lack of knowledge by looking at the effects of current noxious odor on residents' lives in three residential communities in northern New Jersey: West Caldwell, Newark's North Ward and Garfield- Lafayette in Jersey City. The research examines the coping process residents adopt to deal with this environmental annoyance.

In this study I explore two ways residents cope with odor: reactively (trying to keep the odor out of their homes) …

Effectiveness Of Safety Training, Mayeanna Kamara

Theses

The objective of this thesis is to evaluate the effectiveness of safety training modalities which are specifically designed for the non unionized workers in the construction industry. The main hypothesis is to determine whether multimodal and extended training improves the effectiveness of the learning aspects and safety consciousness among the trainees. The study conducted a literature survey on the factors that affects safety outcomes in construction industry, especially for the non unionized workers. The study developed a survey instrument to evaluate effectiveness of safety training. This study intended to prove that a video training is not enough and that hands …

A Comparison Of Software Engines For Simulation Of Closed-Loop Control Systems, Sanket D. Nikam

Theses

A wide array of control system design and simulation software engines is available in market. It includes MATLAB-Simulink, LabVIEW, Maple-MapleSim, Scilab-Scicos, VisSim and Mathematica-Control Professional Suite (CPS). Among all of them MATLAB-Simulink is dominant and widely used software engine. The main aim of this study is to implement different state space control methods for non-linear Furuta pendulum system in each one of them and to compare performance against MATLAB-Simulink.

Different parameters like learning curve, interoperability, flexibility, control design tools, documentation and tech support are considered for efficiency comparison. It is shown that MapleSim has multi-body intuitive physical modeling (acausal) approach …

Interfacially Polymerized Thin Film Composite Membranes On Microporous Polypropylene Supports For Reverse Osmosis Desalination, Chao Li

Theses

The important technique of interfacial polymerization (IP) is used to fabricate thin film composite (TFC) membranes. In experiments here, microporous polypropylene (PP) flat film membranes were used as a support for fabricating TFC membranes for reverse osmosis by the IP technique. Substantial chemical, pH, and solvent resistance is provided by porous polypropylene membranes. Therefore, it is reasonable to choose porous polypropylene membranes as supports to fabricate TFC membranes for reverse osmosis.

The external and the pore surfaces of polypropylene flat film membrane were hydrophilized first by pre-wetting with acetone, then oxidized with chromic acid solution kept at 65°C. Next, the …

Automation Of Anatomic Torsion Monitor For Evaluation And Improvement Of Low Back Dysfunction, Vishal Kumar Singh

Theses

The existing Anatomical Torsion Monitor (ATM) to evaluate mechanical stiffness and viscoelasticity of the low back suffers from various inherent defects. This has to be replaced by an improved device. Also the existing ATM cannot provide oscillations to the low back.

The main objective is to automate the existing ATM for evaluating the low back immediately using objective methods. The specific objective is to provide oscillations for improving the low back dysfunction.

The laser platform and the target chart for recording the readings are dispensed with the existing ATM. Instead, the ultrasound transducers are attached to the pads to record …