Engineering Commons^™

Analysis And Design Of Pulse-Width Modulated Two-Switch Forward Dc-Dc Converter For Universal Laptop Adapter, Venkata Sai Aditya Kumar Choragudi

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The objective of this research is to analyze, design and simulate a two-switch forward pulse-width modulated (PWM) DC-DC converter. The Forward PWM DC-DC converter is originally derived from the buck converter by the addition of a transformer. The transformer is mainly used as a safety feature to electrically isolate input and output stages of the power converter and also to scale the voltage or current. The steady-state analysis is presented for the two-switch PWM DC-DC forward converter in continuous conduction mode (CCM). Based on the analysis, the design equations for two-switch PWM forward DC-DC converter are derived. A design example …

Drop-Shipping At A Promotional Products Distributor, Ramanan Veeraragavan

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During the current economic times, companies are trying to reduce costs by incorporating new strategies into their business plan. Supply chain, in particular the distribution network is one area where an improvement can bring in a healthy return on investment to a company. Drop-shipping is a distribution strategy whereby customer orders are fulfilled by directly delivering products from manufacturer's facility, instead of storing these products at the warehouse. Drop-shipping helps in reducing inventory and material handling costs at the warehouse, but may increase transportation costs due to frequent shipments. This research was motivated by the current operations at a promotional …

Son Is Essential For Nuclear Speckle Organization, Cell Cycle Progression And Pre-Mrna Splicing, Alok S. Sharma

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Nuclear speckles provide important spatial organization and dynamic regulation for pre-mRNA processing factors in mammalian cells. While the nuclear speckle proteome is complex, little is known at the molecular level about how these factors are organized into nuclear speckles or how alterations in the organization of these factors impacts gene expression. We have discovered a new function for a large (2564 amino acid) nuclear speckle protein called Son in maintaining the organization of pre-mRNA processing factors in nuclear speckles. Depletion of Son by RNAi causes snRNP and serine-arginine rich (SR protein) splicing factors to undergo dramatic disorganization into doughnut-shaped nuclear …

Scheduling Surgical Cases In A Constrained Environment, Bharathwaj Vijayakumar

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This research examines a complex surgical case scheduling problem for a publicly-funded hospital in the Midwest United States. Publicly-funded hospitals are typically under tight budget constraints and these hospitals strive to maximize the utilization of their resources such as beds, staff, equipment, operating rooms, etc. These resources are relatively fixed for a publically funded hospital. A manual scheduling approach followed by this hospital does not guarantee optimal solutions and consequently has led to large variation in the utilization of resources. This real-world problem is described in this research as a multi-day, multi-resource, and patient-priority-based surgical case scheduling problem with the …

The Development Of Silver Nanoparticles As Antiviral Agents, John Christopher Trefry

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Silver nanoparticles (AgNPs) have received tremendous attention for their antimicrobial properties; however, many gaps in knowledge exist. To address these issues, three research objectives were examined. The first objective hypothesized AgNPs can be size selected and concentrated via tangential flow ultrafiltration. The second objective hypothesized a high-throughput method could be developed to screen nanoparticle antiviral-activity and cytotoxicity simultaneously. The third objective hypothesized AgNPs inhibit viruses by preventing viral entry.

For objective one, a tangential flow ultrafiltration scheme was tested on AgNPs synthesized via the Creighton Colloid method. AgNPs were analyzed via transmission electron microscopy. In objective two, an HIV-1 vector …

Observer-Based Fault Diagnosis Of Wind Turbines, Songling Zhao

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Because wind is a clean and renewable energy, it is in high demand as an alternative resource of fossil fuels for our daily power supply. Thus, wind turbine technology is wildly applied to convert the wind energy to electrical power. With the size of the wind turbines increased, the maintenance cost of the wind turbines also goes up. Fault diagnosis can significantly help wind turbines to: reduce the maintenance cost, the machinery breakdown, spare parts inventories, total machine downtime, and overtime expenses, and increase machine life, overall productivity, and profit. The technical challenges for fault diagnosis of the wind turbine …

A Domain Specific Language Based Approach For Developing Complex Cloud Computing Applications, Ashwin Kumar Manjunatha

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Computing has changed. Lately, a slew of cheap, ubiquitous, connected mobile devices as well as seemingly unlimited, utility style, pay as you go computing resources has become available at the disposal of the common man. The latter commonly called Cloud Computing (or just Cloud) is democratizing computing by making large computing power accessible to people and corporations around the world easily and economically.

However, taking full advantage of this computing landscape, especially for the data intensive domains, has been hampered by many factors, the primary one being the complexity in developing applications for the variety of available platforms.

This thesis …

Semi-Automated Dental Cast Analysis Software, Mathew Thomas

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Dental casts have been used extensively to study almost all aspects of the human dentition. These aspects varied from the study of tooth form and morphology, inheritance and genetics, growth and development, occlusion, arch alignment and crowding to mathematical determination of dental arch form.

The aim of this project was to develop a tool to semi-automate the measurement of dental casts that would be precise, accurate and efficient. Measurements include tooth widths, arch lengths and widths, angle of rotation and crown area for each tooth.

The task was divided into two different parts: first, the development of semi-automatic software to …

The Functionalization And Characterization Of Adherent Carbon Nanotubes With Silver Nanoparticles For Biological Applications, Adam A. Maleszewski

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The purpose of this project is to form silver nanoparticles (Ag-NP) attached to a hierarchical substrate for possible use in biological applications. The effectiveness of these Ag-NP-containing devices, including biofilters and biosensors, may be dramatically enhanced by the use of hierarchical structures such as carbon nanotubes (CNT), as they offer a high surface area surface suitable for cell-device interactions, while Ag-NP would be a suitable component in many such devices due to its plasmonic surface properties (e.g. in sensor and directed energy applications) and its anti-microbial properties (desirable for fluid filtration due to its low weight. Meaningful control over the …

Determining The Optimal Aisle-Width For Order Picking In Distribution Centers, Sheena R. Wallace-Finney

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Many companies use distribution centers (DC) as hubs for storing and distributing products to customers (e.g., wholesalers, retailers, or consumers). Order picking, a critical activity in every DC, refers to retrieving products from the storage locations to fulfill customer orders. It accounts for over 50% of the DC operating cost. Order picking system design involves several decisions, such as layout of the picking area, storage policy, picking method, material handling equipment, and information technology, to name a few. Aisle configuration (number, length, width, and orientation) is a critical layout decision as it directly affects picker productivity and required space. Previous …

High-Frequency Wide-Range All Digital Phase Locked Loop In 90nm Cmos, Prashanth Muppala

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This thesis presents a high-frequency wide tuning range all digital phase locked loop (ADPLL) in 90 nm CMOS process with 1.2 V power supply. It operates in the frequency range of 2-7.2 GHz with wide linearity and high resolution. The ADPLL uses a wide frequency range digital controlled oscillator (DCO) and averaging technique to obtain fast lock time. The operation of the ADPLL includes both a frequency acquisition state and a phase acquisition state. A novel architecture is implemented in a coarse stage to obtain a monotonically increasing wide frequency range DCO for frequency acquisition and a fine control stage …

Quantification Of Model-Form, Predictive, And Parametric Uncertainties In Simulation-Based Design, Matthew E. Riley

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Traditional uncertainty quantification techniques in simulation-based analysis and design focus upon on the quantification of parametric uncertainties-inherent natural variations of the input variables. This is done by developing a representation of the uncertainties in the parameters and then efficiently propagating this information through the modeling process to develop distributions or metrics regarding the output responses of interest. However, in problems with complex or newer modeling methodologies, the variabilities induced by the modeling process itself-known collectively as model-form and predictive uncertainty-can become a significant, if not greater source of uncertainty to the problem. As such, for efficient and accurate uncertainty measurements, …

Ab Initio Simulations Of Graphene-Based Nanosensor For Detecting No2 And Li, Ahmed Jama Hassan

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Nanosensors, i.e., sensors based on nanomaterials, have the potential of superior performance owing to their size effect, and can have significant effects on detection of pollutants in the environment. Various nanowires have been used in this context. Here we investigate the possibility of NO2 and Li detection using the quantum conductance change in graphene nanoribbon. Quantum conductance modification in graphene nanoribbon upon NO2/Li adsorption was calculated using ab initio methods. The optimized structures of the adsorbed NO2 indicated two different geometries where either nitrogen or oxygen was closer to the graphene lattice. The former resulted in charge transfer from NO2 …

A Collaborative Computational Framework For Multidisciplinary And Reliability-Based Analysis And Optimization Using Sorcer, Karkada Nagesha Aithala

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In a globalized and highly competitive world of product design, collaboration is a necessity to leverage the expertise available among various engineering teams to meet stringent product specifications and strict product delivery schedules reducing the concept to release time, and hence maintaining a competitive edge in the market. Physical location of teams may span organizational firewalls and different countries. Seamless access must be provided to hundreds of design tools that are utilized by the teams to carry out multidisciplinary analysis, optimization, and reliability studies in order to accurately estimate product performance. Service ORiented Computational EnviRonment (SORCER) is one of the …

Cervical Spine Biomechanical Behavior And Injury, Mbulelo T. Makola

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A finite element model of the cervical spine including the C2 through C7 levels was developed in order to study the behavior of the cervical spine region. The model was validated in flexion extension, bending, and rotational load scenarios. The model was found to represent the biomechanical behavior of the cervical spine. The validated cervical spine finite element model was used to study spinal injury and disease processes. The model provided qualitative estimates of load carrying and stress distribution as well as range of motion.

A Computational Tool For Biomolecular Structure Analysis Based On Chemical And Enzymatic Modification Of Native Proteins, Deacon John Sweeney

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Chemical and enzymatic modification of proteins is a well-established treatment technique for probing the conformational properties of these macromolecules. Investigators have recently extended the approach to probe many sites on a protein's structure in parallel manner, such that conformational properties of a target protein can be inferred. The modern approach uses mass spectrometry to quantify reactant loss and product formation. Rigorous analysis is challenging due to the high volume of mass spectrometric data that must be processed and interpreted.

An extensively interactive software suite has been developed to assist various aspects of the analytical protocol. The software offers a variety …

The Molecular Basis Of The Interaction Between The Coxsackievirus And Adenovirus Receptor (Car) And Magi-1, Abimbola Olayinka Kolawole

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A major factor in virus entry into cells is localization and abundance of the primary receptor. The Coxsackievirus and adenovirus receptor (CAR) is the primary receptor for group B coxsackievirus and many serotypes of adenovirus. In most epithelia, a seven exon isoform of CAR (CAR^Ex7) is exclusively localized at the basolateral surface where it behaves as a homophilic adhesion protein and is inaccessible for viral infection. However, in well-differentiated human airway epithelia, we recently discovered an alternatively spliced, low abundance isoform of CAR (CAR^Ex8) that is apically localized where it may initiate apical viral infection. The …

Characterization Of Room Temperature Terahertz Direct Detectors, Carla Renee Boggs

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Room temperature direct detectors operating in the so-called Terahertz (THz) region of the electromagnetic spectrum, and representing the most common detection technologies currently available, were characterized at 104, 280 GHz or 600 GHz within their intended range of operating frequencies. These detectors included commercial Schottky-diode rectifiers (Virginia Diodes and Spacek Labs), commercial pyroelectric detectors (Spectrum Detector), and a commercial Golay cell (QMCI). The characterization included antenna patterns, responsivity, electrical noise, noise equivalent temperature difference (NEΔT ), and noise equivalent power (NEP). Since all the characterization measurements were made the same way, quantitative comparisons can be made between the performances of …

Effect Of Fullerene Nano-Spheres On Evaporation Kinetics Of Fluids, Wenhu Wang

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As the interest in fluid evaporation kinetics keeps increasing, it's inevitably noticed that fullerene nanospheres play an important role on it. In this study, we investigate the C60 nanospheres' effect on the evaporation kinetics and thermal transitions of different solvents (water, chlorobenzene) over the entire range of solubility. According to distinct polarity of different solvent, fullerene solution would behave differently, the trend of increasing in evaporation rate as the concentration increased was observed in aromatic solvents while the rate kept decreasing in water. The result of differential scanning calorimetry (DSC) and Raman spectroscopy provided an evidence about structuring in water …