Engineering Commons^™

Study Of Decarbonization Reaction Of Sodium Carbonate By Sodium Borates, Zaki Yusuf

Dissertations

Today, the chemical process industries are facing many challenges in the wake of skyrocketing energy price. Paper industry as a whole is also not only looking into improving the process efficiency of its chemical recovery process but also is exploring to meet these challenges with gasification based energy/chemical recovery process. Borate based autocausticizing technology appears promising, provided it could be effectively integrated into both types of chemical recovery processes based on the principles of chemistry and chemical engineering.

My research was focused on the decarbonization reactions of sodium carbonate by sodium metaborate (NaBO₂) and sodium diborate (Na_{4 …}

Design And Stability Analysis Of High Performance Packet Switches, Zhen Guo

Dissertations

With the rapid development of optical interconnection technology, high-performance packet switches are required to resolve contentions in a fast manner to satisfy the demand for high throughput and high speed rates. Combined input-crosspoint buffered (CICB) switches are an alternative to input-buffered (IB) packet switches to provide high-performance switching and to relax arbitration timing for packet switches with high-speed ports.

A maximum weight matching (MWM) scheme can provide 100% throughput under admissible traffic for lB switches. However, the high complexity of MWM prohibits its implementation in high-speed switches. In this dissertation, a feedback-based arbitration scheme for CICB switches is studied, where …

Probabilistic Approaches To The Design Of Wireless Ad Hoc And Sensor Networks, Zhen Guo

Dissertations

The emerging wireless technologies has made ubiquitous wireless access a reality and enabled wireless systems to support a large variety of applications. Since the wireless self-configuring networks do not require infrastructure and promise greater flexibility and better coverage, wireless ad hoc and sensor networks have been under intensive research. It is believed that wireless ad hoc and sensor networks can become as important as the Internet. Just as the Internet allows access to digital information anywhere, ad hoc and sensor networks will provide remote interaction with the physical world.

Dynamics of the object distribution is one of the most important …

Dynamic Simulations Of Particle Suspensions Subjected To An External Electric-Field, Xianjin Jiang

Dissertations

A numerical method is performed to study the suspension of polarizable particles in nonconductive solvents subjected to external electric fields. Such particles experience both hydrodynamic and electrostatic interactions. The hydrodynamic force acting on the particles is determined using the Stokesian dynamics method under the assumption that the Reynolds number is much smaller than 1, while the electrostatic force is determined by differentiating the electrostatic energy of the suspension, which is computed from the induced particle dipoles. In addition, the multiple image method is used to compensate for the electrostatic force when two particles are close to each other. Because the …

Multilevel Adaptive Security System, Hongwei Li

Dissertations

Recent trends show increased demand for content-rich media such as images, videos and text in ad-hoc communication. Since such content often tends to be private, sensitive, or paid for, there exists a requirement for securing such information over resource constrained ad hoc networks. In this work, traditional data security mechanisms, existing ad hoc secure routing protocols and multilevel security are first reviewed. Then a new system, called the Multilevel Adaptive Security System, which incorporates the multilevel security concept at both the application layer and the network layer, is proposed to provide adaptive security services for data and routing processes.

MLASS …

Modeling, Design, And Fabrication Of Pulsed Fluidic Micro-Actuators, Max Roman

Dissertations

The forced vibration of a thin flexible plate or membrane in a sealed cavity with a small opening can cause fluid to be pumped into and out-of the cavity. At particular frequencies and amplitudes of vibration, a streaming of vortex rings can occur near the orifice. These vortex rings move under their own self-induced momentum. Downstream of the opening the rings ultimately break up and can form a fully developed jet. This work is dedicated to the analysis, design, and fabrication of electrostatic micro fluidic actuators, which use the pulsing mechanism described above to generate a fluid flow. Particle Image …

The Effects Of Aging On Cardiac Mechanics, Samuel C. Lieber

Dissertations

It is well established that the aging heart exhibits left ventricular (LV) diastolic dysfunction and changes in mechanical properties, which have been attributed to alterations in the extracellular matrix (ECM). The investigators tested the hypothesis that the mechanical properties of cardiac myocytes significantly change with aging thereby contributing to the LV diastolic dysfunction. Cellular mechanical properties were determined by indenting cells with an atomic force microscope (AFM). The indentation results were interpreted by modeling the AFM probe as a blunted cone and determining an apparent elastic modulus (B) with classical infinitesimal strain theory (CIST). A commercially available finite element software …

Mobile Ad Hoc Networks For Intelligent Systems, Zhigang Wang

Dissertations

Advances in wireless technology and portable computing along with demands for high user mobility have provided a major promotion toward the development of ad hoc networks. Mobile ad hoc networks feature dynamic topology, self-organization, limited bandwidth and battery power of a node. They do not rely on specialized routers for path discovery and traffic routing. Research on ad hoc networks has been extensively investigated in the past few years and related work has focused on many of the layers of the communications architecture.

This research intends to investigate applications of MANET for intelligent systems, including intelligent transportation system (ITS), sensor …

Design And Resource Management Of Reconfigurable Multiprocessors For Data-Parallel Applications, Xiaofang Wang

Dissertations

FPGA (Field-Programmable Gate Array)-based custom reconfigurable computing machines have established themselves as low-cost and low-risk alternatives to ASIC (Application-Specific Integrated Circuit) implementations and general-purpose microprocessors in accelerating a wide range of computation-intensive applications. Most often they are Application Specific Programmable Circuiits (ASPCs), which are developer programmable instead of user programmable. The major disadvantages of ASPCs are minimal programmability, and significant time and energy overheads caused by required hardware reconfiguration when the problem size outnumbers the available reconfigurable resources; these problems are expected to become more serious with increases in the FPGA chip size. On the other hand, dominant high-performance computing …

Flow-Oriented Anomaly-Based Detection Of Denial Of Service Attacks With Flow-Control-Assisted Mitigation, Sui Song

Dissertations

Flooding-based distributed denial-of-service (DDoS) attacks present a serious and major threat to the targeted enterprises and hosts. Current protection technologies are still largely inadequate in mitigating such attacks, especially if they are large-scale. In this doctoral dissertation, the Computer Network Management and Control System (CNMCS) is proposed and investigated; it consists of the Flow-based Network Intrusion Detection System (FNIDS), the Flow-based Congestion Control (FCC) System, and the Server Bandwidth Management System (SBMS). These components form a composite defense system intended to protect against DDoS flooding attacks. The system as a whole adopts a flow-oriented and anomaly-based approach to the detection …

Network Level Performance Of Differentiated Services (Diffserv) Networks, Li Zhu

Dissertations

The Differentiated Services (DiffServ) architecture is a promising means of providing Quality of Service (QoS) in Internet. In DiffServ networks, three service classes, or Per-hop Behaviors (PHBs), have been defined: Expedited Forwarding (EF), Assured Forwarding (AF) and Best Effort (BE).

In this dissertation, the performance of DiffServ networks at the network level, such as end-to-end QoS, network stability, and fairness of bandwidth allocation over the entire network have been extensively investigated.

It has been shown in literature that the end-to-end delay of EF traffic can go to infinity even in an over-provisioned network. In this dissertation, a simple scalable aggregate …

Phase Transitions Of Poly (L-Lactic Acid) In Bulk And In Solution, Jing Zhang

Dissertations

Poly(L-lactic acid) (PLLA) has been subject to intensive research in recent years because of its biodegradability. Applications of PLLA, such as porous tissue engineering scaffolds and excipients for controlled release, have been developed in the biomedical and pharmaceutical fields. The crystal structures and morphologies of this semicrystalline polyester are the underlying factors that determine the mechanical and degradation properties of PLLA.

A fundamental understanding of the development of crystal structures and morphologies during the phase transitions of PLLA in bulk and in solution is pursued in this dissertation. Synchrotron wide- and small-angle x-ray scattering (WAXS and SAXS) are adopted as …

Hfo2 As Gate Dielectric On Si And Ge Substrate, Reenu Garg

Dissertations

Hafnium oxide HfO₂ has been considered as an alternative to silicon dioxide SiO₂ in future nano-scale complementary metal-oxide-semiconductor (CMOS) devices since it provides the required capacitance at the reduced device size because of its high dielectric constant. HfO₂ films are currently deposited by various techniques. Many of them require high temperature annealing that can impact device performance and reliability.

In this research, electrical characteristics of capacitors with HfO₂ as gate dielectric deposited by standard thermal evaporation and e-beam evaporation on Si and Ge substrates were investigated. The dielectric constant of HfO₂ deposited by thermal evaporation …

Prediction Of Service Load Of Concrete Structures After Cracking Using Ultrasonic Technique, Xuezeng Wu

Dissertations

The objective of this study is to investigate the cracking behavior of fractured concrete structures and to introduce a new approach to assess their remaining service lives. A novel ultrasonic technique is utilized to detect crack propagation in notched beams of mortar, plain concrete and reinforced concrete. The study showed that crack growth and microcrack zone in cementitious composites can be quantitatively detected by the ultrasound technique.

To predict crack propagation during the fracture process in plain concrete, an effective compliance fracture model is proposed. A large fracture process zone is incorporated in the analytical model by means of an …

Capacitated And Uncapacitated Facilities Locationallocation Problem With Sensitive Prices, Stochastic Demands, And Inventory, Yaser Al-Alawi

Dissertations

This study developed a quantitative model that solves a facility locationallocation (LA) problem that maximizes the net profits generated from expected sales. The model was formulated to take into consideration demand uncertainty, sensitive prices, and existence of inventory for capacitated and uncapacitated facilities. Four new models for the LA problem with stochastic demands and inventory were developed and studied. The four models were combinations of capacitated and uncapacitated facilities and sensitive and insensitive prices.

A new method was proposed for achieving optimality, and an approximation procedure was developed that could find near-optimal solutions for problems that could not be solved …

Heavy Metal Adsorption On Iron Oxide And Iron Oxide-Coated Silica : Macroscopic, Spectroscopic, And Modeling Studies, Ying Xu

Dissertations

To accurately model metal mobility and bioavailability in soils and sediments, systematic sorption studies are needed using representative and well-characterized minerals. Two important surfaces are iron oxide and silica, which are ubiquitous and associated with one another in the environment playing important roles in metal distribution. The objectives of this research are to develop models for predicting speciation and mobility of toxic trace metal ions in groundwater, soils, and sediments when competing ions are present. A model system for soils and sediments, iron oxide-coated silica, was synthesized; the degree of coatings was highly sensitive to the particle size of silica …

Study Of Si/Sio2 Interface Passivation And Sio2 Reliability On Deuterium Implanted Silicon, Tias Kundu

Dissertations

One of the major defects that contribute to the interface states in the silicon band gap is the dangling bond, which degrades performance of MOS devices. Passivation of these bonds with hydrogen had been found to diminish their effect but the improvement degrades the operation due to hot electron effect. Passivation with deuterium annealing has proven to improve the lifetime of the metal oxide semiconductor devices but this technique is not very effective for a multi-level metal-dielectric structure. This work investigates and optimizes incorporation of deuterium by ion implantation into the silicon substrate before the growth of 6.5 nm thin …

Robust Techniques And Applications In Fuzzy Clustering, Amit Banerjee

Dissertations

This dissertation addresses issues central to frizzy classification. The issue of sensitivity to noise and outliers of least squares minimization based clustering techniques, such as Fuzzy c-Means (FCM) and its variants is addressed. In this work, two novel and robust clustering schemes are presented and analyzed in detail. They approach the problem of robustness from different perspectives. The first scheme scales down the FCM memberships of data points based on the distance of the points from the cluster centers. Scaling done on outliers reduces their membership in true clusters. This scheme, known as the Mega-clustering, defines a conceptual mega-cluster which …

Variable Permittivity Dielectric Material Loaded Stepped-Horn Antenna, Ozgur Ozdemir

Dissertations

Stepped-horn antenna loaded with dielectric material of variable permittivity is proposed to improve radiation characteristics and/or to increase the electrical dimensions of the radiating structure compared to unloaded empty one. A hybrid numerical technique is used to analyze such an antenna. The tapered section of the horn antenna is modeled by multi-stepped waveguide structures filled with variable dielectric constant material. Generalized scattering matrix representation of the tapered section of the horn antenna is obtained using mode matching technique. The radiating aperture problem is solved by the method of moments, under the assumption that the horn is terminated by an infinite …

On The Design For Flexibility Of Manufacturing Systems : A Stochiastic Approach, Nathapol Areeratchakul

Dissertations

Flexibility has emerged as one of the most strategic imperatives for company viability in today's fast paced economy. This realization has stimulated extensive research efforts in this area most of which have focused mainly on defining flexibility and its attributes, the need for flexibility and how to measure it. Nevertheless, despite the considerable amount of publications regarding flexibility and its related subjects, insufficient attention has been given to the optimality of the design for flexibility and the inherent needs to meet uncertainty. Bridging this gap is the intent of this work.

In this dissertation, developed analytical models are for the …

Opportunistic Transmission Scheduling For Next Generation Wireless Communication Systems With Multimedia Services, Chengzhou Li

Dissertations

The explosive growth of the Internet and the continued dramatic increase for all wireless services are fueling the demand for increased capacity, data rates, and support of different quality of service (QoS) requirements for different classes of services. Since in the current and future wireless communication infrastructures, the performances of the various services are strongly correlated, as the resources are shared among them, dynamic resource allocation methods should be employed. With the demand for high data rate and support of multiple QoS, the transmission scheduling plays a key role in the efficient resource allocation process in wireless systems. The fundamental …

Energy Efficient Organization And Modeling Of Wireless Sensor Networks, Jin Zhu

Dissertations

With their focus on applications requiring tight coupling with the physical world, as opposed to the personal communication focus of conventional wireless networks, wireless sensor networks pose significantly different design, implementation and deployment challenges. Wireless sensor networks can be used for environmental parameter monitoring, boundary surveillance, target detection and classification, and the facilitation of the decision making process. Multiple sensors provide better monitoring capabilities about parameters that present both spatial and temporal variances, and can deliver valuable inferences about the physical world to the end user.

In this dissertation, the problem of the energy efficient organization and modeling of dynamic …

Optimal Speed Limit For Shared-Use Roadways, Yongqiang Yang

Dissertations

Motor vehicle crashes are a serious social problem in the United States. Each year a large number of motor vehicle crashes occur and many people are killed or injured, resulting in substantial economic costs. To minimize economic costs, it is necessary to determine optimal speed limits on roadways because of the strong relationship among posted speed limit, crash frequency, and crash injury severity.

A comprehensive literature review about the relationship among posted speed limit, crash frequency, and crash injury severity level was conducted. Crash frequency prediction models and crash injury severity models are developed to obtain crash frequency and injury …

Load Interaction Effects On Fatigue Crack Growth, Stoyan Ivanov Stoychev

Dissertations

Load excursions, in the form of tensile and compressive overloads are known to produce interaction effects during subsequent constant amplitude loading. In this work, the fatigue crack growth and crack closure levels, under both constant amplitude and variable amplitude loading, are investigated in the aluminium-lithium alloy 2090-T84, and the aluminium alloys 2024-T351 and 7150-T651. The crack closure measurements were obtained using both a crack tip opening displacement (CTOD) gauge and a crack mouth opening displacement (CMOD) gauge.

Fatigue crack growth tests were performed on specimens of thickness 1.6mm, 3mm, 6mm and 14mm. Tests were performed at load ratios of 0.1 …

Stabilization Of Curtain Coater At High Speeds, Peeyush Tripathi

Dissertations

High-speed curtain coating is an emerging technology trying to gain commercial acceptance by the paper industry as a pre-metered and non-impact coating process. Curtain coating could offer enormous economic and process advantages over conventional coating methods due to non-impact and excellent coverageat reduced coat weights. Due to non-impact and non-contact type of coating operation, curtain coating can operate with fewer sheet breaks or the strength requirements of the base sheet can be greatly reduced. High speed curtain coating for commodity coated grades like LWC is still a challenge. Relationship between various process, basesheet and coating variables and their mechanism must …

Optimization Of Sequential Purification Of Beta-Glucosidase From Tricoderma Reesei In Aqueous Two-Phase System, Shalini Gautam

Dissertations

A novel sequential technique was developed for the purification of a valuable enzyme, beta-glucosidase, from microorganism Tricoderma reesei. The fungus T. reesei produces cellulose degrading enzymes, called cellulases: beta-glucosidase, endo-glucanase and exo-glucanase and low molecular weight proteins. For specific applications, the enzyme must be separated from other contaminants. The sequential technique, that included affinity precipitation with chitosan followed by separation with an aqueous two-phase system (ATPS), was implemented for the purification of beta-glucosidase from the culture filtrate of T. reesei.

The cultivation medium (nutrient) was optimized for the production of betaglucosidase from T. reesei cell culture. Treatment of the …

Nanostructured Composite Materials Based On Carbon Nanotubes And 3-D Photonic Crystals, Jing Chen

Dissertations

Carbon nanotubes (CNT) and in particular, single-wall carbon nanotubes (SWCNT) have been extensively studied, in large part, due to their unique one-dimensional crystalline structures and related electronic and optical properties. Various polymeric composite materials, which were based on carbon nanotubes, have been also developed in an attempt to combine the properties of polymer and CNT in a single film. Such composites were mainly formed by mixing carbon nanotubes within the polymer without special emphasis on the structure and thereby, the nanoscopic properties of the resultant material.

Photonic crystals belong to a class of man-made structures aimed at manipulating the propagation …

Communications Over Fading Channels With Partial Channel Information : Performance And Design Criteria, Xinmin Deng

Dissertations

The effects of system parameters upon the performance are quantified under the assumption that some statistical information of the wireless fading channels is available. These results are useful in determining the optimal design of system parameters. Suboptimal receivers are designed for systems that are constrained in terms of implementation complexity.

The achievable rates are investigated for a wireless communication system when neither the transmitter nor the receiver has prior knowledge of the channel state information (CSI). Quantitative results are provided for independent and identically distributed (i.i.d.) Gaussian signals. A simple, low-duty-cycle signaling scheme is proposed to improve the information rates …

Development Of Adsorption Filtration Process For Virus Removal For Drinking Water Treatment, Vishal Vijay Gawarikar

Dissertations

Recent monitoring studies have indicated that many ground water (GW) sources would benefit from the development of effective technologies for removing viruses. Although reverse osmosis can achieve high log removal it is not economical. The main objective of this study is to test and validate a novel adsorption filtration (AF) technology for removing viruses from GW sources for drinking water production in New Jersey.

The convective diffusion of viruses to adsorbent particle surfaces in flow packed beds (FPB) enhances their removal efficiency if the adsorbent particle size can be decreased to about 100 microns. The development of effective virus removal …

Mechanics Of Biocell Landfill Settlements, Chamil Hiroshan Hettiarachchi

Dissertations

Prediction of landfill gas generation and settlements are of concerns in design and maintenance of biocell landfills. Accurate settlement prediction is essential for design of piping systems used for the delivery of re-circulated leachate and recovery of landfill gas. Landfill settlement is the result of change in overburden stresses and biodegradation of waste. Biodegradation-induced settlement results from the re-arrangement of waste skeleton in response to the decomposition of waste mass.

Current practice of landfill settlement modeling is predominantly empirical, thus most of the available techniques make no attempt to simulate the real mechanisms of waste settlement. Traditionally compressibility index is …