Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 85

Full-Text Articles in Engineering

Drosophila Heart Recognition System Using Convolutional Neural Networks, Yuanhao He May 2015

Drosophila Heart Recognition System Using Convolutional Neural Networks, Yuanhao He

Theses and Dissertations

In this thesis, we introduced a new method of marking the heart region of Drosophila in its different living stages which are known as larva, pupa and adult with convolutional neural networks. The images of Drosophila are acquired by a custom optical coherence microscopy (OCM) system in lab, this method of extracting the heart position of the fly obtained by the convolutional neural network in this article is of considerable significance for future research on the fly heart. We will elaborate in the article on how we completed the training and testing of this model and how we acquire the ...


Optimization Models For Electricity Networks And Renewable Energy Under Uncertainity, Mohsen Moarefdoost Jan 2015

Optimization Models For Electricity Networks And Renewable Energy Under Uncertainity, Mohsen Moarefdoost

Theses and Dissertations

This work focuses on developing optimization models and algorithms to solve problems in electricity networks and renewable energy. The steady rise of electricity demand in the world, along with the deployment of volatile renewable energy resources in greater quantities, will require many researchers, policymakers, and other stakeholders in the field of power management to understand these challenges and use new methods, approaches and technologies to modernize the electric grid. We study reliable and efficient electricity dispatch with minimum costs in power networks and efficient and economic harvesting of ocean wave energy by optimizing wave farm configuration.


Characterizing Targeted Drug Delivery And Endothelial Cell Dynamics Using In Vitro Blood Vessel Models, Antony Thomas Jan 2015

Characterizing Targeted Drug Delivery And Endothelial Cell Dynamics Using In Vitro Blood Vessel Models, Antony Thomas

Theses and Dissertations

Endothelial cells form the inner lining of blood vessels and regulate key blood vessel functions including host defense reactions, vascular smooth muscle tone, angiogenesis, and tissue fluid homeostasis. The occurrence of a pathological condition can lead to inflammation, a protective and tightly regulated response involving host cells, blood vessels and proteins. This process is promoted by circulating cytokines and other chemical mediators such as tumor necrosis factor-alpha (TNF-α), interleukins, thrombin, a few examples. Inflammation can be acute or chronic in nature and is characterized by specific cell receptor expression patterns on the endothelial layer and an increase in endothelial cell-cell ...


Understanding The Structural Basis For Fap Homodimerization, Heterodimerization And Fap Substrate Specificity, Benjamaporn Wonganu Jan 2015

Understanding The Structural Basis For Fap Homodimerization, Heterodimerization And Fap Substrate Specificity, Benjamaporn Wonganu

Theses and Dissertations

Fibroblast activation protein (FAP) is a cell-surface serine protease which promotes invasiveness of certain epithelial cancers. In particular, the heightened expression of FAP in tumor cells and the ability of FAP to degrade major components of the extracellular matrix such as type I collagen makes it attractive as a target for anti-cancer therapeutics. FAP is active only when it is in the form of a dimer. Moreover, FAP also can heterodimerize with dipeptidyl peptidase-IV (DPP-IV) to facilitate tumor cells invasion. Despite the importance of FAP to cancer and other disease processes, the mechanism that regulates FAP homo- and heterodimerization, as ...


Determination Of Rolling Parameters For Numerical Simulation Of Cold Rolling Of Nickel Aluminum Bronze, Giuseppe Iorio Jan 2015

Determination Of Rolling Parameters For Numerical Simulation Of Cold Rolling Of Nickel Aluminum Bronze, Giuseppe Iorio

Theses and Dissertations

The purpose of this work was to conduct a reverse engineering evaluation to attain state variables such as flow stress, strain, and strain rate for a finite element (FE) simulation of the rolling process. The alloy investigated included as cast and wrought Nickel Aluminum Bronze (NAB) of the similar chemistry. Chemical analyses of the materials were in conformance with the ASTM B150 and ASTM B 171 C6200 specifications. Tensile testing results of the wrought material did not show a significant difference between the transverse and longitudinal directions. Microstructural examination of the wrought material in the transverse, and in the longitudinal ...


On The Use Of Self-Assembling Block Copolymers To Toughen A Model Epoxy, Yilin Chen Jan 2015

On The Use Of Self-Assembling Block Copolymers To Toughen A Model Epoxy, Yilin Chen

Theses and Dissertations

Block copolymers have been receiving considerable attention in tougheningepoxy due to their ability to form a wide variety of nanostructures. This study focuseson using both triblock and diblock copolymers to improve the fracture toughness ofan aromatic-amine cured epoxy system. The curing system consisted of 1,3-phenylenediamine (mPDA) as curing agent and aniline as a chain extender. Threetriblock copolymers and three diblock copolymers were incorporated in the samelightly crosslinked model epoxy system, which was chosen to mimic an underfillmaterial in flip-chip packaging for the microelectronics industry.In this research, rubber particles were formed in situ using self-assembling blockcopolymers. Mechanical, thermal and ...


Enhanced First-Order Methods For Convex And Nonconvex Optimization, Xi Bai Jan 2015

Enhanced First-Order Methods For Convex And Nonconvex Optimization, Xi Bai

Theses and Dissertations

First-order methods for convex and nonconvex optimization have been an important research topic in the past few years. This talk studies and develops efficient algorithms of first-order type, to solve a variety of problems. We first focus on the widely studied gradient-based methods in composite convex optimization problems that arise extensively in compressed sensing and machine learning. In particular, we discuss an accelerated first-order scheme and its variants, which enjoy the “optimal” convergence rate for the gradient methods in terms of complexity, and their practical behavior.In the second part of the talk, we present alternating direction type of methods ...


Weldability And Strength Recovery Of Nucu-140 Advanced Naval Steel, Jason Bono Jan 2015

Weldability And Strength Recovery Of Nucu-140 Advanced Naval Steel, Jason Bono

Theses and Dissertations

NUCu-140 is a ferritic copper-precipitation strengthened steel that is a candidate material for use in many naval and structural applications. Previous work has shown that the heat-affected zone (HAZ) and fusion zone (FZ) of NUCu-140 exhibit softening that is due to dissolution of the copper-rich precipitates. This study aims to recover the FZ and HAZ strength by re-precipitation of the copper-rich precipitates through either multiple weld passes or an isothermal post-weld heat treatment (PWHT). The potential use of multiple thermal cycles was investigated with HAZ simulations using a Gleeble thermomechanical simulator. The HAZ simulations represented two weld thermal cycles with ...


Lean And Agile Manufacturing In Natural Food Production: The Key To Saving America's Health And Environment, Emily Gumbulevich Jan 2015

Lean And Agile Manufacturing In Natural Food Production: The Key To Saving America's Health And Environment, Emily Gumbulevich

Theses and Dissertations

Food production in the United States impacts the economy, environment, national security, and public health. Reports that the current system of production is highly vulnerable to terrorist attacks and disease have gone unaddressed for nearly 20 years as issues such as recalls of meat are unnoticed for entire yearlong production cycles and machinery falling into disrepair leaving metal shards behind in processed foods are more prevalent. The rising prevalence of obesity, heart disease, and diabetes have been linked to diet, but the American diet has not changed – largely due to the prevalence of high fructose corn syrup in quickly accessible ...


Microstructural Evolution And Mechanical Properties Of Simulated Heat Affected Zones In Cast Precipitation Hardened Stainless Steels 17-4 And 13-8+Mo, Robert Joseph Hamlin Jan 2015

Microstructural Evolution And Mechanical Properties Of Simulated Heat Affected Zones In Cast Precipitation Hardened Stainless Steels 17-4 And 13-8+Mo, Robert Joseph Hamlin

Theses and Dissertations

Cast precipitation hardened (PH) stainless steels 17-4 and 13-8+Mo are used in applications that require a combination of high strength and moderate corrosion resistance. Many such applications require fabrication and/or casting repair by fusion welding. The purpose of this work is to develop an understanding of microstructural evolution and resultant mechanical properties of these materials when subjected to thermal cycles characteristic of the heat affected zone (HAZ) in a fusion weld. Samples of each material were subjected to weld thermal cycles in solution treated and aged condition (S-A-W condition) and solution treated condition with a post weld thermal ...


Fracture Behavior Of Silica- And Rubber-Nanoparticle-Toughed Epoxies, Amelia Labak Jan 2015

Fracture Behavior Of Silica- And Rubber-Nanoparticle-Toughed Epoxies, Amelia Labak

Theses and Dissertations

Particle-toughened crosslinked epoxies are popular materials for a variety of applications, including the microelectronics industry. For this application, the properties of these materials, such as a high fracture toughness and a low coefficient of thermal expansion, are highly appealing. In order to achieve these properties, inorganic particles are often added into the matrix. For this study, both inorganic and organic particles-toughened epoxies are investigated in the hopes of finding an optimized system.In particular, in this study, micron-sized silica and nano-sized rubbery block copolymers are added to an amine-cured epoxy matrix. A series of rubber-only and silica-only systems are investigated ...


Preparation, Structure And Properties Of Gold-Based ‘Ruby’ Sodium Silicate Glass: A Model Metal-Glass Nano-Composite, Chatree Saiyasombat Jan 2015

Preparation, Structure And Properties Of Gold-Based ‘Ruby’ Sodium Silicate Glass: A Model Metal-Glass Nano-Composite, Chatree Saiyasombat

Theses and Dissertations

Gold ruby glass has been well-known for its deep red color dating back to Roman times but the role of gold nano-particles (AuNPs) in the creation of color was revealed only in 20th century. Glass alchemists discovered early on that addition of tin promotes the development of color. However, the underlying mechanism, which relies on the availability of electrons for oxidation/reduction and growth of AuNP above a minimum size, remains unclear. Additionally, very little information is available on how the electrical properties of such glasses are affected by the presence of gold nanoparticles or tin doping. In this dissertation ...


Power Optimization In Electricity Networks, Fang Chen Jan 2015

Power Optimization In Electricity Networks, Fang Chen

Theses and Dissertations

Today, one main challenge that the energy industry faces is the ability to increase energy efficiency. This requires effort from two entities within the energy system – the rule/policy maker from the upper level who creates standards to properly regulate energy usage or energy-trading processes. Another entity is the rule follower, who reacts to the rules or polices wisely to maximize its own benefits taking into consideration economic and quality-of-life issues. This thesis studies three problems to help the rule follower increase its benefit in the electricity market. In the first problem, a power consumer aims to dispatch its power ...


An Investigation Of Melt Modulation Science For Enhanced Polymer Product Manufacturing, Majed Alsarheed Jan 2015

An Investigation Of Melt Modulation Science For Enhanced Polymer Product Manufacturing, Majed Alsarheed

Theses and Dissertations

The melt modulation concept was originally introduced to control the melt flow during the filling phase of cold runner injection molding machines. Since its inception, several melt modulation systems have been developed. Although previously designed systems successful balanced multi-cavity and family molding parts and controlled weld-line position, they were not commercially viable. The main objective of this dissertation was to employ scientific and business based approaches to develop and enhance a melt modulation technology for cold-runner based injection molding. This research intends to bridge the gap between an important scientific discovery and its industrial applications. This was achieved with the ...


Physics-Model-Based Optimization And Feedback Control Of The Current Profile Dynamics In Fusion Tokamak Reactors, Justin Edwin Barton Jan 2015

Physics-Model-Based Optimization And Feedback Control Of The Current Profile Dynamics In Fusion Tokamak Reactors, Justin Edwin Barton

Theses and Dissertations

As the demand for energy continues to increase, the need to develop alternative energy sources to complement (and one day replace) conventional fossil fuels is becoming increasingly important. One such energy source is nuclear fusion, which has the potential to provide a clean source of energy and possesses an abundant fuel supply. However, due to the technological difficulty in creating the conditions necessary for controlled fusion to occur, nuclear fusion is not yet commercially viable. The tokamak is a device that utilizes magnetic fields to confine the reactants, which are in the plasma state, and it is one of the ...


Asymptotic Fields For Cracks Terminating At Bi-Material Interface With Arbitrary Angles, Xiao Liu Jan 2015

Asymptotic Fields For Cracks Terminating At Bi-Material Interface With Arbitrary Angles, Xiao Liu

Theses and Dissertations

The bi-material crack problem is an interesting and important topic in the field of fracture mechanics. The existing mainstream solutions, either analytical or computational, are commonly focused on some specific cases, e.g., a crack lying on exactly the bonded border of dissimilar materials, or a crack impinging upon a bi-material interface at a right angle. However, little attention is paid to the general cases, i.e., cracks approaching or attacking the material divided border arbitrarily, which is more likely to happen in the engineering products. With any possibility of the crack's incidence angle, the asymmetric nature of the ...


Special Topics In Solid State Diffusion: I. Grain Boundary Variability Ii. Fluid In Deformable Solid, Mahyar Mohebi-Moghadam Jan 2015

Special Topics In Solid State Diffusion: I. Grain Boundary Variability Ii. Fluid In Deformable Solid, Mahyar Mohebi-Moghadam

Theses and Dissertations

In the first part of this study, we investigate the impact of grain-boundary variability on mass transport behavior in a polycrystal. More specifically, we perform both numerical and analytical studies of steady-state diffusion in prototypical microstructures in which there is either a discrete spectrum of grain-boundary activation energies or else a complex distribution of grain-boundary character, and hence a continuous spectrum of boundary activation energies. An effective diffusivity is calculated for these structures using simplified multi-state models and, in some cases, employing experimentally obtained grain-boundary energy data in conjunction with the Borisov assumption. For some condition, we find marked deviations ...


Finite Element Modeling Of Impact-Generated Stress Wave Propagation In Concrete Plates For Non-Destructive Evaluation, Tripti Pradhan Jan 2015

Finite Element Modeling Of Impact-Generated Stress Wave Propagation In Concrete Plates For Non-Destructive Evaluation, Tripti Pradhan

Theses and Dissertations

Impact-echo (IE) is a widely accepted and applied non-destructive evaluation technique for quality control and defect characterization in concrete structures. IE is an acoustic method based on the propagation of impact-generated stress waves that are reflected by material defects or interfaces. Numerical simulations using finite element method (FEM) have been used to study the impact-echo response of structural component with complex geometry and boundary conditions.The present study focuses on developing a modeling methodology to simulate stress wave propagation in concrete plates. The significant modeling parameters that influenced the wave propagation and behavior were identified based on the literature review ...


Design Optimization Of A Portable, Turbine, William Christopher Schleicher Jan 2015

Design Optimization Of A Portable, Turbine, William Christopher Schleicher

Theses and Dissertations

Marine and hydrokinetic (MHK) technology is a growing field that encompasses many different types of turbomachinery that operate on the kinetic energy of water. Micro hydrokinetics are a subset of MHK technology comprised of units designed to produce less than 100 kW of power. A propeller-type hydrokinetic turbine is investigated as a solution for a portable micro-hydrokinetic turbine with the needs of the United States Marine Corps in mind, as well as future commercial applications. This dissertation investigates using a response surface optimization methodology to create optimal turbine blade designs under many operating conditions.The field of hydrokinetics is introduced ...


Signal Processing Techniques And Applications, Feng Shi Jan 2015

Signal Processing Techniques And Applications, Feng Shi

Theses and Dissertations

As the technologies scaling down, more transistors can be fabricated into the same area, which enables the integration of many components into the same substrate, referred to as system-on-chip (SoC). The components on SoC are connected by on-chip global interconnects. It has been shown in the recent International Technology Roadmap of Semiconductors (ITRS) that when scaling down, gate delay decreases, but global interconnect delay increases due to crosstalk. The interconnect delay has become a bottleneck of the overall system performance. Many techniques have been proposed to address crosstalk, such as shielding, buffer insertion, and crosstalk avoidance codes (CACs). The CAC ...


Life-Cycle Management Of Civil And Marine Structures Under Fatigue And Corrosion Effects, Mohamed Soliman Jan 2015

Life-Cycle Management Of Civil And Marine Structures Under Fatigue And Corrosion Effects, Mohamed Soliman

Theses and Dissertations

Infrastructure systems are under continuous deteriorating effects due to various environmental and mechanical stressors. These effects can be generated by sudden threats such as earthquakes, tornadoes, blast, and fire, or gradual deterioration due to fatigue and corrosion. Moreover, as indicated in the 2013 American Society of Civil Engineers (ASCE) Report Card of America's Infrastructure, the United States' infrastructure systems are highly deteriorating with a required estimated investment of 3.6 trillion USD to improve their condition within the next seven years. Given the limited financial resources, rational methodologies are required to support the optimum budget allocation while maintaining maximum ...


A Study Of Membership Functions On Mamdani-Type Fuzzy Inference System For Industrial Decision-Making, Chonghua Wang Jan 2015

A Study Of Membership Functions On Mamdani-Type Fuzzy Inference System For Industrial Decision-Making, Chonghua Wang

Theses and Dissertations

The complexity of product design in industry has been continuously increasing. More factors are required to be taken into account simultaneously before a decision about the new product could be determined. For this reason, decision-making process costs much more time and it may even be impossible to determine the optimal decision by normal calculations. Therefore, Fuzzy Inference System based on Fuzzy Logic is introduced as a quick decision-making tool to arrive at a good decision within much shorter time.This thesis focuses on studying the features of membership functions in Mamdani-type fuzzy inference process. It is aimed at making the ...


Flow Structure On A Rotating Wing: Effect Of Radius Of Gyration, Maxwell Marshall Wolfinger Jan 2015

Flow Structure On A Rotating Wing: Effect Of Radius Of Gyration, Maxwell Marshall Wolfinger

Theses and Dissertations

The flow structure on a rotating wing (flat plate) is characterized over a range of Rossby number Ro = rg/C, in which rg and C are the radius of gyration and chord of the wing, as well as travel distance rgΦ/C, where Φ is the angle of rotation. Wings having low aspect ratio AR = 1, and moderate aspect ratio AR = 2 are considered. Stereoscopic particle image velocimetry (SPIV) is employed to determine the flow patterns on defined planes and, by means of reconstruction, throughout entire volumes. Images including Q-criterion, spanwise vorticity, spanwise velocity, downwash velocity, tangential velocity, vorticity flux ...


A Cell Patterning System Based On Thermal Ink-Jet Technology, Yue Xiao Jan 2015

A Cell Patterning System Based On Thermal Ink-Jet Technology, Yue Xiao

Theses and Dissertations

Tissue engineering has a significant impact on biological and medical area. It helps to eventually realize the repair, replace or improve tissue function or even the complete organ. Inkjet cell printing, as a simple and novel way in bio-fabrication, is a promising tool to fabricate cell pattern and scaffolds that directly serve the purpose of tissue engineering.This thesis introduces a thermal inkjet cell printing device. The mechanical design, software and pertinent test data are described. The specification of the printhead, a customized printing substrate and operating procedure is also presented. The printing device uses a thermal inkjet printhead to ...


Autogenous Welding On A Flat Plate: The Effect Of Phase Change Transformation On Residual Stress, Bin Yang Jan 2015

Autogenous Welding On A Flat Plate: The Effect Of Phase Change Transformation On Residual Stress, Bin Yang

Theses and Dissertations

The objective of this study is to predict the magnitude and spatial variation of the residual stresses in an autogenously welded flat plate. Autogenous welding is a fusion welding process using heat without the addition of filler metal to join two pieces of the same metal. The residual stresses in a flat plate, close to the weld pool, are closely examined in this study. Using the welding simulation program SYSWELD, a 2-D geometric model was constructed using ANSYS 15.0, then meshed with quadratic 2-D elements in Visual-Mesh 10.0. In this study, mesh refinement is critical, especially near the ...


The Capacitated Reliable Fixed-Charge Location Problem: Model And Algorithm, Rui Yu Jan 2015

The Capacitated Reliable Fixed-Charge Location Problem: Model And Algorithm, Rui Yu

Theses and Dissertations

Many classical facility location models, like the uncapacitated fixed-charge location problem (known as UFLP), implicitly assume that the facilities will operate well all the time. However, in fact, facilities may fail sometimes due to natural or economic factors. The reliability fixed-charge location problem (RFLP) is based on the UFLP, taking failures into account. Both the UFLP and the RFLP assume that facilities are uncapacitated, which is obviously not true in reality. Capacity limits in reality may mean that customers have to be served from facilities much farther than their egularly assigned facilities at dierent levels. In this thesis, we present ...


Design And Fabrication Of Ultrathin Plasmonic Nanostructures For Photovoltaics, Color Filtering And Biosensing, Beibei Zeng Jan 2015

Design And Fabrication Of Ultrathin Plasmonic Nanostructures For Photovoltaics, Color Filtering And Biosensing, Beibei Zeng

Theses and Dissertations

Since the first report of the extraordinary optical transmission (EOT) phenomenon through periodic subwavelength hole arrays milled in optically-thick metal film, plasmonics have generated considerable interest because they enable new fundamental science and application technologies. Central to this phenomenon is the role of surface plasmon polaritons (SPPs), which are essentially electromagnetic waves trapped at the interface between a metal and a dielectric medium through their interactions with free electrons at the metal surface. The resonant interaction between the incident light and surface charge oscillations enables the concentration and manipulation of light at deep subwavelength scales, opening up exciting application opportunities ...


Ligh Extraction And Nanomaterials For Iii-Nitride Based White Light-Emitting Diode, Peifen Zhu Jan 2015

Ligh Extraction And Nanomaterials For Iii-Nitride Based White Light-Emitting Diode, Peifen Zhu

Theses and Dissertations

The importance of having low-cost and practical technology for improving the efficiency of solid-state lighting is key for the practical implementation of this technology for general illumination market. The thin-film flip-chip (TFFC) LED has been pursued as the state-of-the-art LED technology, which has been shown to have improved extraction by 1.6 times over the conventional planar LED technology. The combination of the thin-film concept with flip-chip technology provided surface brightness and flux output advantages over conventional LED, and currently the TFFC LEDs are widely used in industry for improved performance. To improve the light extraction further in TFFC LEDs ...


Redundancy, Reliability Updating, And Risk-Based Maintenance Optimization Of Aging Structures, Benjin Zhu Jan 2015

Redundancy, Reliability Updating, And Risk-Based Maintenance Optimization Of Aging Structures, Benjin Zhu

Theses and Dissertations

The presence of uncertainties in the structural design process requires the incorporation of system reliability and redundancy concepts in the design specifications. AASHTO Load and Resistance Factor Design specifications utilize a factor relating to redundancy from the load side in the strength limit state to account for system redundancy in the component design. However, the classification of the component redundancy level is very general and the evaluation of values for this factor is also very subjective. Moreover, this factor does not account for several parameters that have significant effects on the system redundancy. Therefore, there is room for further improvement ...


Operando Molecular Spectroscopy During Catalytic Biomass Pyrolysis, Christopher Keturakis Jan 2015

Operando Molecular Spectroscopy During Catalytic Biomass Pyrolysis, Christopher Keturakis

Theses and Dissertations

With the declining amount of fossil fuel resources, the need to develop sustainable processes that produce liquid hydrocarbon fuels has stimulated an explosion of research in biomass conversion technologies. One of the simplest biomass conversion methods that results in a liquid hydrocarbon fuel is catalytic biomass pyrolysis. Catalytic biomass pyrolysis has been examined from process technology and catalyst discovery points of view, but the lack of a well-defined catalyst with known molecular structure(s) has hampered the development of catalyst structure-activity relationships for value-added chemicals and fuels. Supported Al2O3/SiO2 catalysts were synthesized and extensively characterized using ex situ high ...