Engineering Commons^™

The Current Picture And The Future Vision Of The Ship Recycling Industry : The Contributions Of Japan To Achieving Sustainable, Safe And Environmentally Sound Recycling Of Ships, Yasuhiro Urano

World Maritime University Dissertations

First of all, as a basis of the discussion in this dissertation, the international regulatory instruments which cover ship recycling industry, namely, the Basel Convention, 1989 and the Hong Kong Convention, 2009, are examined focusing on their essential principles and limitations. Second, the present conditions of the ship recycling industry in the Indian subcontinent are investigated in order to make clear the problems to be addressed. The focus of the investigation is set on ships’ potential hazards, environmental risks of the beaching method, hazardous waste flow, workers’ occupational safety and health, and causes of substandard recycling operations. Furthermore, the key …

The Role Of The Ship Breaking Industry In Bangladesh And Its Future With Special Emphasis On Capacity Building Through Education And Training, Kazi A.B.M. Shameem

World Maritime University Dissertations

The ship breaking is considered to be the most sustainable way of disposing end of life ships. Incentives behind the development of the shipbreaking industry are multi-faceted, among which economic benefits and employment opportunities are most prominent. Yet the industry received much attention globally due to many fatal accidents causing loss of life, degradation of environmental due to the prevailing unsafe working practices especially in south Asia. This dissertation is a study to understand the shipbreaking in general with influencing factors for driving and holding its position in south Asia particularly in Bangladesh. The shipping & demolition market dynamics analyzed …

Energy Savings And Peak Demand Reduction Of A Seer 21 Heat Pump Vs. A Seer 13 Heat Pump With Attic And Indoor Duct Systems - December 2011, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

Experiments were run in an unoccupied 1600 ft2 house, the Manufactured Housing (MH Lab) at the Florida Solar Energy Center (FSEC), to evaluate the delivered performance as well as the relative performance of a SEER 21 variable capacity heat pump versus a SEER 13 heat pump. The performance was evaluated with two different duct systems: a standard attic duct system and an indoor duct system located in a dropped-ceiling space.

Enhanced Microbial Utilization Of Recalcitrant Cellulose By An Ex Vivo Cellulosome-Microbe Complex, Chun You, Xiao-Zhou Zhang, Noppadon Sathitsuksanoh, Lee R. Lynd

Dartmouth Scholarship

A cellulosome-microbe complex was assembled ex vivo on the surface of Bacillus subtilis displaying a miniscaffoldin that can bind with three dockerin-containing cellulase components: the endoglucanase Cel5, the processive endoglucanase Cel9, and the cellobiohydrolase Cel48. The hydrolysis performances of the synthetic cellulosome bound to living cells, the synthetic cellulosome, a noncomplexed cellulase mixture with the same catalytic components, and a commercial fungal enzyme mixture were investigated on low-accessibility recalcitrant Avicel and high accessibility regenerated amorphous cellulose (RAC). The cellbound cellulosome exhibited 4.5- and 2.3-fold-higher hydrolysis ability than cell-free cellulosome on Avicel and RAC, respectively. The cellulosome-microbe synergy was not completely …

Agent-Based Model Of Aerial Ad-Hoc Network Market Potential, Christopher B. Watkins, Cihan H. Dagli

Engineering Management and Systems Engineering Faculty Research & Creative Works

Mobile Ad hoc NETworks (MANETs) have seen significant growth as a research topic in recent years. as opposed to a traditional network with a fixed node infrastructure, the nodes in a MANET are free to move and arbitrarily organize themselves while maintaining wireless communication with each other. the major benefit of MANETs is the lack of reliance on a fixed network infrastructure. the challenge is to dynamically route traffic through a set of mobile network nodes. MANETs represent a novel solution for providing internet access in aircraft. Currently, each aircraft maintains its own gateway to the internet using expensive satellite …

Cluster Control Of Automated Surface Vessels, Paul David Mahacek

Mechanical Engineering Senior Theses

This research focuses on the design and control of a fleet of robotic kayaks, and presents experimental data regarding the functionality and performance of the system. One of the key technical challenges in fielding multi-robot systems for real-world applications is the coordination and relative motion control of the individual units. Coordinated formation control of the fleet is implemented through the use of the cluster space control architecture, which is a full-order controller that treats the fleet as a virtual, articulating, kinematic mechanism. The resulting system is capable of autonomous navigation utilizing a centralized controller, currently implemented via a shore-based computer …

A Cfd Model For Thermal Conversion Of Thermally Thick Biomass Particles, Ramin Mehrabian, Selma Zahirovic, Robert Scharler, Ingwald Obernberger, Stefan Kleditzsch, Siegmar Wirtz, Victor Scherer, Hong Lu, Larry L. Baxter

Faculty Publications

A one-dimensional model for the thermal conversion of thermally thick biomass particles is developed for the simulation of the fuel bed of biomass grate furnaces. The model can be applied for cylindrical and spherical particles. The particle is divided into four layers corresponding to the main stages of biomass thermal conversion. The energy and mass conservation equations are solved for each layer. The reactions are assigned to the boundaries. The model can predict the intra-particle temperature gradient, the particle mass loss rate as well as the time-dependent variations of particle size and density, as the most essential features of particle …

Geometrical Frustration In Nanowire Growth, K. W. Schwarz, J. Tersoff, S. Kodambaka, Y.C. Chou, F. M. Ross

Birck and NCN Publications

Idealized nanowire geometries assume stable sidewalls at right angles to the growth front. Here we report growth simulations that include a mix of nonorthogonal facet orientations, as for Au-catalyzed Si. We compare these with in situ microscopy observations, finding striking correspondences. In both experiments and simulations, there are distinct growth modes that accommodate the lack of right angles in different ways-one through sawtooth-textured sidewalls, the other through a growth front at an angle to the growth axis. Small changes in conditions can reversibly switch the growth between modes. The fundamental differences between these modes have important implications for control of …

Internal Electric Fields Due To Piezoelectric And Spontaneous Polarizations In Cdzno/Mgzno Quantum Well, H. C. Jeon, S. J. Lee, Tae Won Kang, S. H. Park, Yung Kee Yeo, T. F. George

Faculty Publications

We have investigated optical properties as a function of internal and external fields in the quantum well (QW). Optical properties of CdZnO/MgZnO QW structures are investigated by using many‐body effects. The CdZnO/MgZnO QW structure with high Cd composition is found to have smaller optical gain because the strain‐induced piezoelectric polarization and the spontaneous polarization in the well increase with the inclusion of Cd. These results demonstrate that high performance laser diode operation can be realized in CdZnO/MgZnO QW structures by reducing those polarizations adopting dipole reverse method.

Exploitation Of Unintentional Information Leakage From Integrated Circuits, William E. Cobb

Theses and Dissertations

Unintentional electromagnetic emissions are used to recognize or verify the identity of a unique integrated circuit (IC) based on fabrication process-induced variations in a manner analogous to biometric human identification. The effectiveness of the technique is demonstrated through an extensive empirical study, with results presented indicating correct device identification success rates of greater than 99:5%, and average verification equal error rates (EERs) of less than 0:05% for 40 near-identical devices. The proposed approach is suitable for security applications involving commodity commercial ICs, with substantial cost and scalability advantages over existing approaches. A systematic leakage mapping methodology is also proposed to …

Use Of The Richtmyer-Meshkov Instability To Infer Yield Stress At High-Energy Densities, Guy Dimonte, G. Terrones, F. J. Cherne, T. C. Germann, Virginie Dupont, K. Kadau, W. T. Buttler, D. M. Oro, C. Morris, D. L. Preston

Aerospace Engineering - Daytona Beach

We use the Richtmyer-Meshkov instability (RMI) at a metal-gas interface to infer the metal’s yield stress (Y) under shock loading and release. We first model how Y stabilizes the RMI using hydrodynamics simulations with a perfectly plastic constitutive relation for copper (Cu). The model is then tested with molecular dynamics (MD) of crystalline Cu by comparing the inferred Y from RMI simulations with direct stress-strain calculations, both with MD at the same conditions. Finally, new RMI experiments with solid Cu validate our simulation-based model and infer Y~0.47 GPa for a 36 GPa shock.

Linear-Quadratic Control Of A Mems Micromirror Using Kalman Filtering, Jamie P. Schnapp

Theses and Dissertations

The deflection limitations of electrostatic flexure-beam actuators are well known. Specifically, as the beam is actuated and the gap traversed, the restoring force necessary for equilibrium increases proportionally with the displacement to first order, while the electrostatic actuating force increases with the inverse square of the gap. Equilibrium, and thus stable open-loop voltage control, ceases at one-third the total gap distance, leading to actuator snap-in. A Kalman Filter is designed with an appropriately complex state dynamics model to accurately estimate actuator deflection given voltage input and capacitance measurements, which are then used by a Linear Quadratic controller to generate a …

Link Performance Analysis For A Proposed Future Architecture Of The Air Force Satellite Control Network, Eric W. Nelson

Theses and Dissertations

The Air Force Satellite Control Network (AFSCN) is a worldwide network of ground stations that support a wide variety of users from the National Aeronautics and Space Administration (NASA) to the National Reconnaissance Office (NRO). The network performs tracking, telemetry, and commanding (TT&C) for these varied users. Users, located at Satellite Operations Centers (SOC), must compete for time on the AFSCN. This thesis demonstrates how to predict satellite link performance, specifically by users of the AFSCN. It will also demonstrate how users might use this capability to save spacecraft power. A tool was created called the AFSCN Link Predictor (LP) …

A Method For Measuring Programmatic Dependency And Interdependency Between Dod Acquisition Programs, Matthew B. Christensen

Theses and Dissertations

There is currently no accepted method for quantitative measurement of acquisition program interdependency. While some methods exist for measuring dependency or interdependency at the component or system level, these methods do not translate well to program interdependency measurement. The objective of this thesis is to provide a model for measuring acquisition program interdependency accurately and quantitatively. The model presented in this thesis uses four Interdependency Factors to identify dependency relationships between programs. Specific Interdependency Levels are then used to measure the strengths of those dependencies. The model also accounts for measurement of dependencies upon programs that are not directly connected, …

Investigation Of Gallium Nitride Transistor Reliability Through Accelerated Life Testing And Modeling, Bradley D. Christiansen

Theses and Dissertations

Gallium nitride high electron mobility transistors are attractive to the DoD for their ability to operate at high frequencies, voltages, temperatures, and power. Yet, there are concerns about the reliability of these devices. Various degradation mechanisms and their causes are proposed in the literature. A variety of reliability tests were conducted to understand these mechanisms and causes. A multi-stressor experiment revealed different failure mechanisms than are in the literature. In particular, the devices tested at high voltage in the OFF state did not degrade significantly as suggested by others' reports. The validity of temperature-accelerated life testing when applied to GaN …

Rapid Development: A Content Analysis Comparison Of Literature And Purposive Sampling Of Afrl Rapid Reaction Projects, Andrew R. Smith

Theses and Dissertations

In the current environment of military operations requesting faster delivery schedules to counter insurgent tactics, the engineering team often searches for how to quickly deliver the 80% solution, typically in 6-12 months. These are labeled rapid development projects. A content analysis of best practices in commercial product development literature, where time to market is often a driving factor, was accomplished showing varying emphasis of systems engineering technical and technical management processes. Technical Planning, Stakeholders Requirements Development, and Architecture Design were identified as important processes. This analysis confirms preconceived notions of plan upfront and early by emphasizing the SE processes of …

Electroluminescence Studies On Longwavelength Indium Arsenide Quantum Dot Microcavities Grown On Gallium Arsenide, John C. Ramsey

Theses and Dissertations

A comprehensive study of the electroluminescence of four GaAs/AlGaAs microcavity devices with InAs/GaInAs quantum dot active regions emitting near 1.3 µm was conducted. The four molecular beam epitaxial grown samples with AlAs oxide aperture confinement layers were fabricated, characterized, and optically modeled. Optical power transmission of the samples was modeled using Matlab and compared with measured transmission data. Resonant cavity light emitting diodes (RCLEDs) and three vertical cavity surface emitting laser (VCSEL) samples were fabricated and electro-optically characterized over a range of injection currents and temperatures. Devices achieved continuous wave room temperature lasing at 1.28 µm with an output power …

Construction Of Mse Wall Using Tire Shred-Sand Mixture As Backfill (Spr-3470), Monica Prezzi, Varenya Kumar Duvvuru Mohan

JTRP Other Publications and Reports

A large number of waste tires are generated each year throughout the world. Instead of disposing these tires in landfills, they can be used beneficially in road construction, MSE walls or structural fills that require large quantities of material. Such use of tires not only saves the costs of landfilling, but also provides certain desirable mechanical properties. The focus of this research was on determining important geotechnical properties of tire shred-sand mixtures required for their use as a lightweight backfill for MSE walls. Accordingly, the shear strength and pullout characteristics of tire shred-sand mixtures at various mixing ratios were determined …

Critical And Phase-Equilibrium Properties Of An Ab Initio Based Potential Model Of Methanol And 1-Propanol Using Two-Phase Molecular Dynamics Simulations, Sonal Patel, W. Vincent Wilding, Richard L. Rowley

Faculty Publications

Two-phase molecular dynamics simulations employing a Monte Carlo volume sampling method were performed using an ab initio based force field model parameterized to reproduce quantum-mechanical dimer energies for methanol and 1-propanol at temperatures approaching the critical temperature. The intermolecular potential models were used to obtain the binodal vapor-liquid phase dome at temperatures to within about 10 K of the critical temperature. The efficacy of two all-atom, site-site pair potential models, developed solely from the energy landscape obtained from high-level ab initio pair interactions, was tested for the first time. The first model was regressed from the ab initio landscape without …

Formation Of Organized Nanostructures From Unstable Bilayers Of Thin Metallic Liquids, Mikhail Khenner, Sagar Yadavali, Ramki Kalyanaraman

Mathematics Faculty Publications

Dewetting of pulsed-laser irradiated, thin (< 20 nm), optically reflective metallic bilayers on an optically transparent substrate with a reflective support layer is studied within the lubrication equations model. A steady-state bilayer film thickness (h) dependent temperature profile is derived based on the mean substrate temperature estimated from the elaborate thermal model of transient heating and melting/freezing. Large thermocapillary forces are observed along the plane of the liquid-liquid and liquid-gas interfaces due to this h-dependent temperature, which, in turn, is strongly influenced by the h-dependent laser light reflection and absorption. Consequently the dewetting is a result of the competition between thermocapillary and intermolecular forces. A linear analysis of the dewetting length scales established that the non-isothermal calculations better predict the experimental results as compared to the isothermal case within the bounding Hamaker coefficients. Subsequently, a computational non-linear dynamics study of the dewetting pathway was performed for Ag/Co and Co/Ag bilayer systems to predict the morphology evolution. We found that the systems evolve towards formation of different morphologies, including core-shell, embedded, or stacked nanostructure morphologies.

Development Of Photographic Dynamic Measurements Applicable To Evaluation Of Flapping Wing Micro Air Vehicles, Jeremy C. Murray

Theses and Dissertations

Developments in the area of flapping wing micro air vehicles (FWMAVs) of a small size and with limited range. This has lead to a great deal of interest in biomimetric designs based on flapping wing flyers, including the North American Hawkmoth (Manduca Sexta). By utilizing high speed photography and photogrammetry the dynamic flapping of the wing can be characterized for comparison with mathematical models, namely computational fluid dynamics (CFD) and finite element analysis (FEA).To successfully utilize high speed image capture, a method of successfully digitizing many data points in a short period of time needs to be developed. The effort …

Self-Regenerating Nanotips For Low-Power Electric Propulsion (Ep) Cathodes, Lyon Bradley King

Michigan Tech Patents

Spindt-type field-emission cathodes for use in electric propulsion (EP) systems having self-assembling nanostructures that can repeatedly regenerate damaged cathode emitter nanotips. A nanotip is created by applying a negative potential near the surface of a liquefied base metal to create a Taylor cone converging to a nanotip, and solidifying the Taylor cone for use as a field-emission cathode. When the nanotip of the Taylor cone becomes sufficiently blunted or damaged to affect its utility, the base metal is re-liquefied by application of a heat source, a negative potential is reapplied to the surface of the base metal to recreate the …

Developments In Performance Monitoring Of Concrete Exposed To Extreme Environments., W. J. Mccarter, T. M. Chrisp, G. Starrs, A. Adamson, E. Owens, P. A. M. Basheer, S. V. Nanukuttan, S. Srinivasan, Niall Holmes

Articles

The performance of the surface zone of concrete is acknowledged as a major factor governing the rate of deterioration of reinforced concrete structures because it provides the only barrier to the ingress of water containing dissolved ionic species such as chlorides, which ultimately initiate corrosion of the reinforcement. In situ monitoring of cover-zone concrete is therefore critical in attempting to make realistic predictions as to the in-service performance of the structure. To this end, this paper presents developments in a remote interrogation system to allow for continuous, real-time monitoring of the cover-zone concrete from an office setting. Use is made …

Aerosol-Assisted Synthesis Of Monodisperse Single-Crystalline Α-Cristobalite Nanospheres, Xingmao Jiang, Lihong Bao, Yung-Sung Cheng, Darren R. Dunphy, Xiaodong Li, C. Jeffrey Brinker

Faculty Publications

Monodisperse single-crystalline α-cristobalite nanospheres have been synthesized by hydrocarbon-pyrolysis-induced carbon deposition on amorphous silica aerosol nanoparticles, devitrification of the coated silica at high temperature, and subsequent carbon removal by oxidation. The nanosphere size can be well controlled by tuning the size of the colloidal silica precursor. Uniform, high-purity nanocrystalline α-cristobalite is important for catalysis, nanocomposites, advanced polishing, and understanding silica nanotoxicology.

Highly Sensitive Refractive Index Optical Fiber Sensors Fabricated By A Femtosecond Laser, Jinpeng Yang, Lan Jiang, Sumei Wang, Qianghua Chen, Benye Li, Hai Xiao

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Highly sensitive and robust refractive index (RI) fiber sensors are proposed, which are based on concatenating two micro air-cavities. the micro air-cavities embedded in the fiber along the core axis are fabricated by combining the techniques of femtosecond laser micromachining and arc fusion splicing. the full width at half-maximum (FWHM) of an attenuation peak of a sensor in air is 0.048 nm, and the extinction ratio is ∼15 dB. When the diameter of the cavity is slightly larger than the fiber core diameter, the sensor is highly sensitive to external RI changes. a high sensitivity of 172.4 nm/refractive index unit …

Uwb System Based On Energy Detection Of Derivatives Of The Gaussian Pulse, Song Cui, Fuqin Xiong

Electrical and Computer Engineering Faculty Publications

A new method for energy detection ultra-wideband systems is proposed. The transmitter of this method uses two pulses that are different-order derivatives of the Gaussian pulse to transmit bit 0 or 1. These pulses are appropriately chosen to separate their spectra in the frequency domain. The receiver is composed of two energydetection branches. Each branch has a filter which captures the signal energy of either bit 0 or 1. The outputs of the two branches are subtracted from each other to generate the decision statistic. The value of this decision statistic is compared to the threshold to determine the transmitted …

A Comparative Evaluation Of An Educational Program Designed To Enable Mechanical Engineering Students To Develop Global Competence, Aaron Gerald Ball

Theses and Dissertations

The 'flattening of the world', using Thomas Friedman's phraseology, is driving corporations to increasingly use collaborative engineering processes and global teams to operate on a global scale. Globalization of the traditional university engineering curriculum is necessary to help students prepare to work in a global environment. More scalable and economically sustainable program types are needed to enable the majority of students to obtain a globalized education. The purpose of this research was to determine how effectively a global team- and project-based computer aided engineering course provided learning opportunities that enabled students to develop elements of global competence in comparison to …

Computational Modeling For Transportation Network Security, Sherif A. Tolba

Master's Theses

No abstract provided.

Dynamic Test Scheduling In Hardware-In-The-Loop Simulation Of Commercial Vehicles, Tenil Cletus

Master's Theses

Modern day commercial vehicles are controlled by various Electronic Control Units (ECU). They are not only tested as single units, but also by networking them in Controlled Area Network bus (CAN) to form a complete electrical control system. This is achieved using Hardware In the Loop (HIL) Integration Lab. In HIL, the electrical system is connected to a real time mathematical model of the vehicle plus it’s environment so as to form a loop.

Testing functionality of the electrical system begins by defining functional tests. An example would be testing cruise control activation. Executing each test is made possible by …

Bias Correction And Downscaling Of Climate Model Outputs Required For Impact Assessments Of Climate Change In The U.S. Northeast, Kazi F. Ahmed

Master's Theses

Global Climate Models (GCMs) are the typical sources of future climate data required for impact assessments of climate change. However, GCM outputs are related to model-related uncertainties and involve a great deal of biases. Bias correction of model outputs is, therefore, necessary before their use in impact studies. The coarse resolution of GCM simulations is another hindrance to their direct use in fine-scale impact analysis of climate change. Although downscaling of GCM outputs can be performed by dynamical downscaling using Regional Climate Models (RCMs), it requires large computational capacity. When daily climate data from multiple GCMs are required to be …