Engineering Commons^™

Analysis Of Marine Container Terminal Gate Congestion, Truck Waiting Cost, And System Optimization, Chang Qian Guan

Dissertations

As world container volume continues to grow and the introduction of 12,000 TEUs plus containerships into major trade routes, the port industry is under pressure to deal with the ever increasing freight volume. Gate congestion at marine container terminal is considered a major issue facing truckers who come to the terminal for container pickup and delivery. Harbor truckers operate in a very competitive environment; they are paid by trip, not by the hours they drive. Gate congestion is not only detrimental to their economic well-being, but also causes environmental pollution.

This thesis applies a multi-server queuing model to analyze marine …

Optimizing Replenishment Order Quantities In Uncoordinated Supply Chains, Atipol Kanchanapiboon

Dissertations

Many modern supply chains can be described as a series of uncoordinated suppliers. That is each supplier establishes their individual inventory and production policies on both the input and output sides. In these supply links there is minimal coordination between suppliers, and typically only prices and delivery guarantees are contracted. As a consequence, the inventory behavior and associated costs do not exhibit standard patterns. This makes it difficult to model and optimize these chains using classical inventory models. The common approach, therefore, for evaluating uncoordinated supply chains is to use Supply Chain Analytics software. These retrieve operational data from Enterprise …

Heterogeneous Flow Structure And Gas-Solid Transport Of Riser, Jun You

Dissertations

This study aims to understand physical mechanisms of gas-solid transport and riser flow, investigate heterogeneous flow structures of gas-solid transport and their formation mechanism of the in riser flows, both in axial and radial directions. It provides sound interpretation for the experimental observation and valuable suggestion to riser reactor design. Chemical reaction is also coupled with flow hydrodynamics to board the industrial applications. This study mainly focuses on mathematical modeling approach based upon physical mechanism, and endeavor to validate model prediction against available experimental data.

First of all, most important physical mechanisms including inter-particle collision force, gas/solid interfacial force and …

On Modeling And Mitigating New Breed Of Dos Attacks, Amey Bhaskar Shevtekar

Dissertations

Denial of Service (DoS) attacks pose serious threats to the Internet, exerting in tremendous impact on our daily lives that are heavily dependent on the good health of the Internet. This dissertation aims to achieve two objectives:1) to model new possibilities of the low rate DoS attacks; 2) to develop effective mitigation mechanisms to counter the threat from low rate DoS attacks.

A new stealthy DDoS attack model referred to as the "quiet" attack is proposed in this dissertation. The attack traffic consists of TCP traffic only. Widely used botnets in today's various attacks and newly introduced network feedback control …

Sensorimotor Experience In Virtual Environments, Katherine Grace August

Dissertations

The goal of rehabilitation is to reduce impairment and provide functional improvements resulting in quality participation in activities of life, Plasticity and motor learning principles provide inspiration for therapeutic interventions including movement repetition in a virtual reality environment, The objective of this research work was to investigate functional specific measurements (kinematic, behavioral) and neural correlates of motor experience of hand gesture activities in virtual environments stimulating sensory experience (VE) using a hand agent model. The fMRI compatible Virtual Environment Sign Language Instruction (VESLI) System was designed and developed to provide a number of rehabilitation and measurement features, to identify optimal …

Clustered Wireless Sensor Networks, Renita Margaret Machado

Dissertations

The study of topology in randomly deployed wireless sensor networks (WSNs) is important in addressing the fundamental issue of stochastic coverage resulting from randomness in the deployment procedure and power management algorithms. This dissertation defines and studies clustered WSNs, WSNs whose topology due to the deployment procedure and the application requirements results in the phenomenon of clustering or clumping of nodes. The first part of this dissertation analyzes a range of topologies of clustered WSNs and their impact on the primary sensing objectives of coverage and connectivity. By exploiting the inherent advantages of clustered topologies of nodes, this dissertation presents …

In Vitro Comparison Of A New Stand-Alone Anterior Lumbar Interbody Cage Device With Established Fixation Techniques, Nitin Chawla

Theses

Around 70% of the population in the United States experience low back pain at some point of their lives, of these 4% underwent surgical intervention on the lumbar spine to relieve the pain. Spinal arthrodesis, i.e. joint fusion, is beneficial in many cases as the final option for patients suffering from certain types of low back pain (LBP). In order to promote solid fusion across a decompressed spinal segment, interbody spacers/cages are used with and without posterior instrumentation to provide an initial "rigid" fixation of the segment.

In this study three fresh/frozen human cadaveric lumbar spines were used. Each lumbar …

Experimental Investigation Of Mixing Time In A Stirred, Torispherical-Bottomed Tank Equipped With A Retreat-Blade Impeller, Nonjaros Chomcharn

Theses

Glass-lined reactors are typically used in the pharmaceutical and specialty chemicals industries because of their material compatibility with most reactants and their cleanability. These reactors are typically equipped with a retreat-blade impeller placed close to the bottom of the tank a single baffle mounted from the top. The mixing performance of such reactors has not received significant attention in the literature, despite their ubiquitous presence in the pharmaceutical industry. In particular, mixing time, i.e., the time required by the system to achieve a predefined level of homogeneity, has not been studied to any significant degree.

In this work, the mixing …

Reliability Of Resting Brain Networks Using Fmri, Suril Rajeshkumar Gohel

Theses

Resting state FMRI studies on human subjects are primarily focused on elaborating effects of resting state brain networks on task induced paradigm and to check consistency of these networks between different groups of populations. Recent studies have shown consistency of RSFC networks within same subjects with intra-site and intra-session variation.

The primary objective of this study was to check consistency of resting state networks between sites and between different groups of people in spite of change in scanning parameters and population. A total of 437 subjects resting state FMRI data from six different sites were collected varying in age group …

An In Vitro Study To Characterize A New Automated High Throughput Neuronal Stretch Injury System, Nicolae Valerian Hususan

Theses

Traumatic brain injury (TBI) is one of the most prevalent long-term neurological conditions and its overall economic consequences rival that of stroke. Considering the importance of the topic, new models for studying TBI are often designed and created. Based on a model developed by the University of Pennsylvania, NJIT constructed a fully automated version, which injures neuronal cell cultures in uniaxial regime and provides the high experimental yield required in pharmaceutical and neuroscience studies.

In this investigation, a new methodology for culturing primary cortical neurons of rat origin was established. Viable cell cultures developed for the first time in NJIT …

Mixing Performance Of A Novel, Continuous Confined Impinging Jets Mixer Using Competitive Reactions, Han Zheng

Theses

In this work, a novel continuous flow apparatus featuring the impingement of fluid jet streams in the presence of ultrasonic energy provided by an ultrasonic probe was tested using competitive reactions in order to determine its mixing effectiveness. The ultrasonic energy enhances micromixing of the fluid jet streams, which results in an overall mixing effectiveness improvements in different physical and chemical processes.

In the competitive reactions system used here (third Bourne reaction), one stream containing sodium hydroxide was continuously fed to the first impinging jet, while an aqueous solution of hydrochloric acid and ethyl chloroacetate was fed to the second …

Development Of An Experimental System To Determine The Contribution Of Titin And Collagen To Passive Stiffness Of Myocardium, Saurin Bharat Shah

Theses

Diastolic dysfunction is known to be a major factor for congestive heart failure in aged humans and other mammals. The main contributors to increase in the myocardial stiffness, hindering the cardiac mechanics, are alterations in intracellular titin and extracellular collagen matrix. Titin is a giant extensible protein, the third filament of striated muscle after actin and myosin, which provides elasticity to passive sarcomeres. The aim of this study is to develop an efficient experimental system that will prove to be instrumental in comparing the contribution of titin against collagen to the passive stiffness of cardiac muscle extracted from experimental animals …

Anisotropic Metamaterials Emulated By Tapered Waveguides: Application To Optical Cloaking, Igor I. Smolyaninov, Vera N. Smolyaninova, Alexander V. Kildishev, V. M. Shalaev

Birck and NCN Publications

We demonstrate that metamaterial devices requiring anisotropic dielectric permittivity and magnetic permeability may be emulated by specially designed tapered waveguides. This approach leads to low-loss, broadband performance. Based on this technique, we demonstrate broadband electromagnetic cloaking in the visible frequency range on a scale similar to 100 times larger than the wavelength.

Structural Optimization Of Joined-Wing Beam Model With Bend-Twist Coupling Using Equivalent Static Loads, Nicholas S. Green

Theses and Dissertations

This study is based on the merger of two separate theories to further the efficiency with which joined-wing structural models are designed. The first theory is Geometrically Exact Beam Theory (GEBT). GEBT is a small strain beam theory which is capable of accurately capturing the geometric bend-twist coupling in beam elements that are experiencing large global deformations. This is crucial to the joined-wing problem as it is geometrically nonlinear. The second theory concerns Equivalent Static Loads (ESL). These ESL consist of a load vector that produces the same nodal displacements and rotations as those computed from a pure nonlinear analysis. …

An Internal Representation For Adaptive Online Parallelization, Koy D. Rehme

Theses and Dissertations

Future computer processors may have tens or hundreds of cores, increasing the need for efficient parallel programming models. The nature of multicore processors will present applications with the challenge of diversity: a variety of operating environments, architectures, and data will be available and the compiler will have no foreknowledge of the environment until run time. Adaptive Online Parallelization (ADOPAR) is a unifying framework that attempts to overcome diver sity by separating discovery and packaging of parallelism. Scheduling for execution may then occur at run time when diversity may best be resolved. This work presents a compact representation of parallelism based …

Integrated Actuation And Energy Harvesting In Prestressed Piezoelectric Synthetic Jets, Poorna Mane

Theses and Dissertations

With the looming energy crisis compounded by the global economic downturn there is an urgent need to increase energy efficiency and to discover new energy sources. An approach to solve this problem is to improve the efficiency of aerodynamic vehicles by using active flow control tools such as synthetic jet actuators. These devices are able to reduce fuel consumption and streamlined vehicle design by reducing drag and weight, and increasing maneuverability. Hence, the main goal of this dissertation is to study factors that affect the efficiency of synthetic jets by incorporating energy harvesting into actuator design using prestressed piezoelectric composites. …

Effect Of Liquid Dispersion On Corrosion Behavior Of Metals In Gas/Liquid/Solid Multiphase Corrosion Systems, Jing Jiang, Jia Wang

Journal of Electrochemistry

Liquid dispersion,described by the parameters of gas/liquid/solid three-phase boundary(TPB) zone of dispersed liquid on a metal surface,is an important property of liquid state influencing corrosion behavior of metals in gas/liquid/solid multiphase corrosion systems.In our paper,the characterisation of cathodic oxygen reduction process in TPB zone was discussed,and a model describing the cathodic process of TPB zone was developed.On this basis,the relationship between the cathodic limiting current and the TPB parameters was studied,and the simulation results were in good agreement with the experimental data.The role of liquid dispersion in atmospheric and sandy soil corrosion systems was also simulated.

Electrodeposition Of Al On Magnesium Alloy In Ionic Liquid, Wen-Ta Tsai, Shu-You Chen, Mu-Huan Zhuang, Jeng-Kuei Chang, Yi-Wen Sun

Journal of Electrochemistry

Electrodeposition of a metallic aluminum on a magnesium alloy in acidic aluminum chloride-1-ethyl-3-methylimidazolium chloride ionic liquids(AlCl₃-EMIC) was investigated.The effects of current density and AlCl₃ content in the ionic liquid on the electrodeposition behavior were studied.The results showed that aluminum could be successfully electrodeposited on the AZ91D substrate.At-0.2 V,the ionic liquid containing 60 m/o AlCl₃ was optimum for Al electrodeposition.The current efficiency was higher if electrodeposition was performed at a lower applied current density.The existence of Al coating could caused a substantial increase in open circuit potential,reducing the susceptibility of Mg alloy to corrosion.The results of electrochemical …

Electrochemical Characteristics Of Vitaminb6 At Polybromocresol Green Modified Electrode, Jun Yao, Jiang-Yuan Li, Yang Luo

Journal of Electrochemistry

Electrochemical characteristics of VB₆ were investigated at PBG modified electrode by Cyclic voltammetry and linear sweep voltammetry.The VB₆ produced an irreversible oxidation peak at 0.978 V(Vs.SCE) in HAc-NaAc(pH=4.0) buffer solution over the potential range of 0.7 to 1.2 V.The electron number,the proton number,the transfer coefficient were determined to be 1,1 and 0.37,respectively.The oxidation peak currents of VB₆ versus its concentration showed a linear relationship in the concentration range of 1×10^-3~2×10^-5mol/L with the correlation coefficient of 0.9967 and the detection limit of 2×10^-6mol/L.The recovery was 100.06%.

Corrosion Performance Of Epoxy Coatings By Chemical Modification With Silanes, Liang Liu, Wei-Gang Ji, Ji-Ming Hu, Jian-Qing Zhang, Chu-Nan Cao

Journal of Electrochemistry

The improvement of corrosion performance of epoxy coatings by modification with "active" and "non-active" silanes is presented."Active" silanes are defined as ones having functional groups that can react with the epoxy groups in the epoxy resin,usually amino-silanes."Non-active" silanes are defined as ones not reacting with the epoxy groups,but can react with the hydroxyl groups in the epoxy backbone by the condensation reactions under the catalysis of organic tin compounds.The FTIR results showed that both the "active" and "non-active" silanes had been successfully grafted onto the epoxy resin.Electrochemical impedance spectroscopy(EIS) and accelerated corrosion test(Machu test) showed that the corrosion performance of …

Electrode Of Metallic Oxides Coated Titanium With Interlayer, Yi Tang, Li-Kun Xu, Yong-Lei Xin, Jun-Tao Wang, Ping Long

Journal of Electrochemistry

Various Ti/IrRuSn,Ti/IrTa/IrRuSn and Ti/IrTaSn/IrRuSn oxide electrodes were prepared by sol-gel method.The surface morphology and microstructure were analysed with FESEM and XRD.The electrochemical activity and stability were investigated using electrochemical technologies including chlorine and oxygen evolving potential measurements,cyclic voltammetry,accelerated life test,and alternative electrolysis.The results indicate that the electrodes with interlayers present more cracks on the surface and a little bigger average grain size,with particles of different shapes precipitated in the cracks.The electroactive sites are increased and the selectivity for the chlorine evolving reaction is enhanced,but the current efficiency for the chlorine production is somewhat lowered by the addition of different interlayers.The …

The Accelerated Test Of Simulated Atmospheric Corrosion And The Rust Evolution Of Low Carbon Steel, Jun-Hua Dong, Wei Ke

Journal of Electrochemistry

It has been set up an accelerated method of simulating to atmospheric corrosion by using wet/dry alternate test.The rust evolution rule of mass change vs time(in logarithmic coordinate) of low carbon steel under this test shows two linear sections with different slopes,in which the rust evolution transition in weight change corresponds to the compactness transition and crystallization transition during the rust layer growth.It has found that the rust evolution rule of low carbon steel in Wanning exposure site correlates to the rust evolution rule obtained by simulating the coastal atmospheric corrosion test,and the rust evolution rule of low carbon steel …

Investigation Of Electrochemical Noise In The Crevice Corrosion Of Q235 Carbon Cteel, Qian Hu, Yu-Bing Qiu, Xing-Peng Guo

Journal of Electrochemistry

The crevice corrosion behavior of Q235 carbon steels in a NaHCO₃+NaCl solution was investigated by electrochemical noise(EN) and electrochemical impedance spectroscopy(EIS).Three stages of crevice corrosion including the induction,the rapid transform and the stable development could be clearly distinguished.The characteristics of the electrochemical noise and the noise resistance Rn showed remarkable differences at each stage.The electrode area ratio(r) of outside to inside the crevice had a significant influence in the development of crevice corrosion.The time of the induction stage increased with increasing r.However,under the stable development stage of the crevice corrosion,the surface outside the crevice was at an active …

Effect Of Naphthalene Water Reducer On Corrosion Behavior Of Reinforcing Steel In Concrete, Yu-Ming Tang, Jie Zhang, Yu Zuo

Journal of Electrochemistry

The influence of naphthalene water reducer on corrosion behavior of reinforcing steel in concrete was studied by the methods of corrosion potential measurement,linear polarization and EIS test.The values of concrete resistance(Rc) and polarization resistance(Rp) of the samples with naphthalene water reducer were higher than those without naphthalene water reducer,especially in the concrete with 0.2 percent naphthalene water reducer.A suitable amount of water reducer can improve the pore structures of concrete,increase the concrete compactness and impermeability,and decrease corrosion rate of rebars in concrete.

Effect Of Electrochemical Property Of Uns J91450 Stainless Steel On Stress Corrosion Cracking In Hydrogen Sulfide Solutions, Zhi-Yong Liu, Chao-Fang Dong, Xiao-Gang Li, Li-Xian Wang

Journal of Electrochemistry

Effect of electrochemical behaviours on stress corrosion cracking(SCC) of UNS J91450 stainless steel in hydrogen sulfide environment was investigated using slow-strain-rate test(SSRT) and electchemial techniques.Results show that UNS J91540 stainless steel was susceptible to SCC in varying H₂S solutions,and the SCC susceptibility reduced with the increase of pH value.The electrochemical property plays an important role in the SCC occurrence,as a combined effect of hydrogen embritlement and anodic dissolution at SCC cracktip at open circuit potential.In the solution with a lower pH the hydrogen revolution was intensive and the cracktip anodic dissolution was weaker,however,in the higher pH solution the …

Frequency Response Of The Skin On The Head And Neck During Production Of Selected Speech Sounds, Jacob B. Munger

Theses and Dissertations

Vibration within the vocal tract during speech is transmitted through body tissue to the skin surface and can be used to transmit speech. Achieving quality speech signals using skin vibration is desirable but problematic, primarily due to the different sources of sound during speech. The objective of this study was to characterize the frequency content of speech signals at various locations on the head and neck. Signals were recorded using accelerometers attached to 15 locations on the heads and necks of 14 males and 10 females as well as a microphone to record audible speech. The subjects produced several isolated …

Developments Of Scanning Electrochemical Probes And Their Applications In Studying Of Localized Corrosions, Chang-Jian Lin, Yan Li, Bin Lin, Rong-Gang Hu, Min Zhang, Xiang-Dong Zhuo, Rong-Gui Du

Journal of Electrochemistry

The electrochemical inhomogeneities always exist at the interface of metal/solution,and play an important and often controlling role in localized corrosion of metals in a given environment.It is necessary to develop in situ imaging techniques for further studying the electrochemical and environmental inhomogeneities at the interface of metal/solution for the localized corrosion system.In this paper,various techniques with spatial resolution,such as scanning micro reference electrode(SMET),scanning electrochemical microscope(SECM),atomic force microscope(AFM),and scanning Kelvin probe(SKP),and their applications in corrosion studies were briefly reviewed.The chemical probes and array electrode have been developed.It was concentrated to describe our newly developed techniques of the scanning electrochemical probes,including SMET …

Preparation And Electrochemical Properties Of Layered Manganese Oxide(Li-Birnessite Type), Xing-Kang Huang, Hai-Tao Chang, Jian-Long Gan, Qing-Shun Zhang, Hong-Jun Yue, Dong-Ping Lv, Yong Yang

Journal of Electrochemistry

Layered Li-birnessite was prepared by means of oxidizing Mn²⁺ with O₂ gas in alkaline media.The as-prepared sample was characterized by scanning electron microscopy(SEM), X-ray diffraction(XRD), BET and thermogravimetric/diffenential thermal analysis(TG/DTA) techniques. The electrochemical properties of the material were also investigated. The results show that such a Li-birnessite consists of well-crystallized spherical particles with an interlayer distance of 0.70 nm. The Li-birnessite delivered a high discharge capacity of 203 mAh/g at a rate of 0.2 C(40 mA/g), and had good rate capability as well.

Electrochemical Behavior Of Mg-Li Electrodes In Nacl Solution, Lin Wu, Yan-Zhuo Lv, Xue Cao, Gui-Ling Wang, Dian-Xue Cao

Journal of Electrochemistry

The Mg-Li electrodes containing 8.5% and 14% Li were prepared using an induction melting method. Their electrochemical behavior in NaCl solution was investigated by means of potentiodynamic polarization, potentiostatic oxidation,electrochemical impedance technique and mass-loss measurements. The morphology of the electrodes after discharge was examined using scanning electron microscopy. The Mg-14Li electrode showed more negative open circuit potential and higher discharge current density than Mg-8.5Li electrode. The oxidation products of Mg-14Li loosely attached on the electrode surface and peeled off easily. The Mg-8.5Li exhibited higher utilization efficiency. Both electrodes gave higher utilization efficiencies when discharged at lower anodic potential.

Electrochemical Performance Of The Exfoliated Graphite Containing Sulfur Cathode Material For Lithium Sulfur Battery, Ke-Guo Yuan, Wei-Kun Wang, Zhong-Bao Yu, An-Bang Wang

Journal of Electrochemistry

The exfoliated graphite containing sulfur cathode material was prepared by the high temperature sulfur gas diffusion adsorption method.This cathode material could obtain an initial discharge specific capacity 972 mAh·g^-1,capacity retention ratio 78% and cycling efficiency above 80%,respectively.The exfoliated graphite containing sulfur cathode could decrease the reaction interphase charge transfer impedance,and restrain the sulfur or polysulfide shuttle phenomenon during the charge-discharge process through improving the diffusion impedance.