Engineering Commons^™

Direct - Drive Permanent Magnet Synchronous Generator Design For Hydrokinetic Energy Extraction, Amshumaan Raghunatha Kashyap

Masters Theses

"Hydrokinetic turbines deliver lower shaft speeds when compared to both steam and wind turbines. Hence, a water wheel generator must operate at speeds as low as 150 - 600 rpm. This thesis describes a permanent magnet synchronous generator (PMSG) that was designed, built, and tested to serve a low speed hydrokinetic turbine. The design methodology was emphasized since designing an application specific generator poses various design and hardware construction issues. These are torque, speed, power and start-up requirements. This generator was built to operate without a speed increaser, implying very low speeds. FEA and performance results from the simulation done …

A Calibration Free Vector Network Analyzer, Arpit Kothari

Masters Theses

"Recently, two novel single-port, phase-shifter based vector network analyzer (VNA) systems were developed and tested at X-band (8.2 - 12.4 GHz) and Ka-band (26.4 - 40 GHz), respectively. These systems operate based on electronically moving the standing wave pattern, set up in a waveguide, over a Schottky detector and sample the standing wave voltage for several phase shift values. Once this system is fully characterized, all parameters in the system become known and hence theoretically, no other correction (or calibration) should be required to obtain the reflection coefficient, (Γ), of an unknown load. This makes this type of VNA "calibration …

Methods For Evaluating Effect Of Operators On Drag Line Energy Efficiency, Maryam Abdi Oskouei

Masters Theses

"Draglines are dominant machines and the most significant electricity consumers in surface coal mines. With the growing price of energy, environmental concerns, and the high sensitivity of mine profitability to dragline productivity, any improvement in efficiency of dragline will be beneficial for mines. Research has shown that operator practices have a significant impact on energy efficiency of mining loading tools. However, not enough work has been done to provide guidance on how to quantitatively assess the effect of operator practices on dragline energy efficiency.

The objectives of this work were to: (i) test the hypothesis that dragline operator's practices and …

Stochastic-Optimization Of Equipment Productivity In Multi-Seam Formations, Elijah Adadzi

Masters Theses

"Short and long range planning and execution for multi-seam coal formations (MSFs) are challenging with complex extraction mechanisms. Stripping equipment selection and scheduling are functions of the physical dynamics of the mine and the operational mechanisms of its components, thus its productivity is dependent on these parameters. Previous research studies did not incorporate quantitative relationships between equipment productivities and extraction dynamics in MSFs. The intrinsic variability of excavation and spoiling dynamics must also form part of existing models. This research formulates quantitative relationships of equipment productivities using Branch-and-Bound algorithms and Lagrange Parameterization approaches. The stochastic processes are resolved via Monte …

Kinetics Of Human And Bovine Insulin Amyloid Fibril Formation In The Presence Of Solid/Liquid Interfaces, Paulina Barranco Morales

Masters Theses

"The purpose of this thesis was to study the rate and extent of aggregation of human and bovine insulin in bulk and in the presence of either polystyrene microspheres with different surface chemistries or liposomes of different composition. Insulin aggregation was followed by turbidimetry, Fourier transform infrared spectroscopy (FTIR), and dynamic light scattering. The Congo red assay was used to corroborate the presence of amyloid deposits and transmission electron microscopy (TEM) was used to analyze the morphology of the amyloid deposits. Our results show that not all the surfaces shortened the lag time. On the other hand, most surfaces had …

The Use Of Elemental Powder Mixes In Laser-Based Additive Manufacturing, Rodney Michael Clayton

Masters Theses

"This study examines the use and functionality of laser depositing alloys from mixes of elemental metallic powders. Through the use of laser-based additive manufacturing (LAM), near net-shaped 3-Dimensional metallic parts can be produced in a layer-by-layer fashion. It is customary for pre-alloyed powders to be used in this process. However, mixes of elemental powders can be used to produce alloys that are formed during the deposition process. This alternative technique requires that the elemental powders adequately mix during deposition for a homogeneous deposit to be produced. Cost savings and versatility are among several of the advantages to using elemental powder …

Protein Aggregation At Solid/Liquid Interfaces: A Monte Carlo Study With Explicit And Implicit Solvent Effects, Rehman Fazeem

Masters Theses

"Metropolis Monte Carlo (MC) simulations were performed with positively charged peptides in aqueous solution to study changes in peptide conformations at solid/liquid interface, and its effects on protein aggregation. Intermediate-resolution diblock model peptide, comprising of 10 units of ALA (non-polar) and LYS (polar) amino acid residues, was used for the simulations. In the first approach to modeling, solvent effects were considered explicitly. The explicit model was then used to study two peptide molecules, in helical structure, at solid/liquid interface. In order to increase the number of peptide molecules in the simulation box, with reduced computational cost, an implicit solvent model …

Development Of An Optimization Model To Determine Sampling Levels, Zlatan Hamzic

Masters Theses

"As the complexity of multi-component products increases the quality of these products becomes increasingly difficult to control. The first step to manufacturing a quality product is making sure that the components of the product meet specifications. Product quality can be controlled through sampling inspection of the components. Two models were developed in this research to determine the optimal sampling levels for incoming lots containing parts for production and assembly of multi-component systems. The main objective of the first model is to minimize the expected cost that is associated with a nonconforming item reaching assembly. In this model the time available …

Characterization Of Rabinal, Guatemala Clay And Development Of An Engineered Surrogate For The Purpose Of Laboratory Study, Lara Anne Hubbel

Masters Theses

"Ceramic pot filters (CPFs) have been proven to be an effective, low cost household water treatment system that are commonly used in third world countries. They are made using local clay, burn out material and colloidal silver or silver nitrate. Challenges faced by researchers include difficulty in acquiring filters from their manufacturing facilities without incurring damage and the cost of shipping. Acquiring the clay material used to make the filters is also difficult due to the cost of shipping and permits necessary to import soil. There have been studies conducted that compared laboratory made CPFs made with native clay and …

Libration Point Orbits Near Small Bodies In The Elliptic Restricted Three-Body Problem, Bharat Mahajan

Masters Theses

"In this study, the feasibility of using libration point orbits to explore small solar system bodies, including asteroids and comets, is considered. A novel design for a small body mission is proposed that makes use of libration point orbits as "parking" orbits. In considering a human exploration mission to asteroids or comets, these "parking" orbits may provide benefits including a safe vantage point for staging/observation, reduced perturbation effects from the nonuniform gravitational field of the body, fewer communication blackouts, ease of guidance and control of a lander on the surface, etc. Because small solar system bodies have extremely low mass …

Wideband Characterization Of Printed Circuit Board Materials Up To 50 Ghz, Aleksei Rakov

Masters Theses

"A traveling-wave technique developed a few years ago in the Missouri S&T EMC Laboratory has been employed until now for characterization of PCB materials over a broad frequency range up to 30 GHz. This technique includes measuring S-parameters of the specially designed PCB test vehicles. An extension of the frequency range of printed circuit board laminate dielectric and copper foil characterization is an important problem. In this work, a new PCB test vehicle design for operating up to 50 GHz has been proposed. As the frequency range of measurements increases, the analysis of errors and uncertainties in measuring dielectric properties …

Computational Fluid Dynamics Flow Comparison Between Openhole Sleeve And Plug-And-Perf Completion In A Hydraulic Fractured Horizontal Well, Viriyah Theppornprapakorn

Masters Theses

"Multi-stage hydraulic fracture completions in horizontal wells have facilitated economic development of natural gas from unconventional and tight gas reservoirs.Industry has relied on two horizontal multi-stage completion technologies: cemented and perforated liner or Plug-and-perf method and Openhole Sleeve Multi-stage method. Each method has its own advantages and disadvantages. However, one of the most important questions is which method yields better gas production? Computation fluid dynamics (CFD) is a powerful tool for solving complex fluid flow problems. In well completion design, CFD plays a significant role aiding the completion engineers on making decision on well completion methods. In this study, a …

Use Of Ultra-High Performance Concrete To Mitigate Impact And Explosive Threats, Julie Anne Willey

Masters Theses

"This study is a continuation of research conducted by Natalia Carey, Anthony Wulfers, and Dr. John Myers under the DHS ALERT Center. Carey investigated the use of polyurea coating systems to mitigate close range blast threats on wall panels. Wulfers continued this by using both polyurea coatings as well as a sacrificial wood fiber fly ash (WF-FA) layer to try to get increased performance. This research was aimed at the study of ultra-high performance concrete (UHPC) for the use in impact and blast mitigation. There is little information on the performance of UHPC under close range blast loading; therefore it …

A Study Of Clustering Rssi And Lqi From Wireless Network Communications, Yanwen Wang

Masters Theses

"In today's information world, different wireless sensor network topologies are permitted to exist in the same geographical region. For example, a city contains thousands of enterprise networks; a school might include different wireless network topologies used by students and faculties respectively. Even within a building, there might be multiple companies that use their own wireless networks. These networks might cause interference to other networks. How to detect, determine and locate the unknown wireless topologies in the same geographical area becomes quite significant in the wireless industry, especially in military use, such as spy-nodes detection and communication orientation systems. In this …

Effects Of Material Variables And Process Parameters On Properties Of Investment Casting Shells, Priyatham Tumurugoti

Masters Theses

"Manufacture of investment casting shells is a complex process. The choice of raw materials - refractory powders or grains, binders and additives - affects the properties of investment casting shells. In this study, different systems of shells were prepared, according to a design of experiments, with commercially available raw materials that differ in chemistry, particle size or particle size distribution. Shell strength was measured in green, fired and cooled, and hot conditions and the results were analyzed for strength-material property relation. Various microstructures of polished cross sections of these shells were characterized using scanning electron microscope. It was determined that …

Improving Life Cycle Management Plans For Power Plant Components, Srinath Raghavan

Masters Theses

"Life cycle management (LCM) combines a set of technical and economic activities with the specific goal of improving the long term economic value of an asset. It is necessary to perform a sound LCM exercise on the utility or industrial asset to maintain the profitability of a plant. In most industries, the maintenance budget is either higher than optimal or lower than required, that result in expensive outages, damages and accidents. An LCM plan is a guide to make operational decision for a component over its life cycle. LCM typically consists of a preventive maintenance schedule, condition monitoring, inspection activities, …

Processing And Properties Of Zrb₂-Zrsi₂ Matrix Composites Reinforced With Continuous Sic Fiber, Benjamin John Bowin Lai

Masters Theses

"The research presented in this thesis focuses on the processing, microstructure, and mechanical properties of ZrB₂-based composites. The main goal was to develop a process that incorporates high strength continuous SiC fiber in a ZrB₂-based matrix. In order to achieve this, the densification, microstructure, and mechanical properties of ZrB₂-ZrSi₂ monolithic ceramics were characterized along with various SiC fiber reinforced ceramic matrix composites (CMCs) utilizing the same matrix.

There were two main areas of study in this thesis. The initial study demonstrated that additions of ZrSi₂ into a ZrB₂ ceramic increases densification at significantly reduced processing temperatures ≤1600ºC). This study revealed …

Women In Science 2013, Clark Science Center's Summer Research Fellows Program

SURF Abstracts (Women in Science)

“Women in Science” summarizes research done by Smith College’s Summer Research Fellowship (SURF) Program participants. Ever since its 1967 start, SURF has been a cornerstone of Smith’s science education. In 2013, 167 students participated in SURF, supervised by 57 faculty mentor-advisors drawn from the Clark Science Center’s fourteen science, mathematics, and engineering departments and programs, and associated centers and units. At summer’s end, SURF participants were asked to summarize their research experiences for this publication.

Comparative Evaluation Of Operating Life For Phosphate-Specific Ion Exchange Resins, Brooke K. Mayer

Civil and Environmental Engineering Faculty Research and Publications

No abstract provided.

Probabilistic Sea-Level Rise Hazard Analysis, Ting Lin

Civil and Environmental Engineering Faculty Research and Publications

This paper proposes a framework termed Probabilistic Sea-Level Rise Hazard Analysis (PSLRHA), to integrate the sea-level rise knowledge of current climate change scientific communities for informed engineering and policy decisions that affect coastal infrastructure, populations, and ecosystems. PSLRHA combines probabilities of all emission scenarios with predictions of the resulting sea-level rise over time, in order to compute sea-level rise hazard. PSLRHA also incorporates uncertainties in those sea-level rise predictions, by considering multiple Sea-Level Rise Prediction Models (SLRPMs). The output of the PSLRHA framework could be a Global Sea-Level Rise Hazard Map (GSLRHM) that can be used for Performance- Based Sea-Level …

Episodic Adaptations And Trade-Offs: Examples From The Victorian Construction Industry, Manikam Pillay, David Borys

Research outputs 2013

A central facet of resilience engineering involves adaptation which involves making temporal adjustments by responding, monitoring, anticipation and learning from disturbances continuous stressors. This ability to adapt is inherent in the actions which manifest as behaviors in individuals and teams. In the main, the response is generally in response is to regular and irregular threats such that work continues to operate as normal. Invariably, these adaptations also require trade-offs and sacrifices being made at a number of levels. However, there is little published research that seeks to explain how such adaptations actually occur in construction works. It has been suggested …

Analysis Of Laminated Anisotropic Plates And Shells Via A Modified Complementary Energy Principle Approach, Martin Claude Domfang

Dissertations (1934 -)

The present work is concerned with the finite element structural analysis of laminated anisotropic plates and shells. New elements based on a modified complementary energy principle are proposed to improve the analysis of such composite structures. Third order deformation plate and shell models incorporating a convergence parameter are developed to govern the general displacement field.

An eight-node isoparametric quadrilateral element with two independent cross-sectional rotations and three normal displacements is utilized to describe the displacement field. The present modified complementary energy formulation incorporates a number of in-plane strain functions of various orders. The corresponding in-plane stresses for each lamina are …

A Window Of Opportunity: Assessing Behavioural Scoring, Kenneth Kennedy, Brian Mac Namee, Sarah Jane Delany, Michael O'Sullivan, Neil Watson

Articles

After credit has been granted, lenders use behavioural scoring to assess the likelihood of default occurring during some specific outcome period. This assessment is based on customers’ repayment performance over a given fixed period. Often the outcome period and fixed performance period are arbitrarily selected, causing instability in making predictions. Behavioural scoring has failed to receive the same attention from researchers as application scoring. The bias for application scoring research can be attributed, in part, to the large volume of data required for behavioural scoring studies. Furthermore, the commercial sensitivities associated with such a large pool of customer data often …

Retaining The People Who Know Your Business Exploring Knowledge Sharing As A Tool To Improve Employee Retention In The Hotel Sector, Vincent Mckenna

Dissertations

The retention of core workers in the hotel/hospitality sector is a key challenge for human resource management, organisational strategies and operational effectiveness. The purpose of this research was to investigate and evaluate the impact of the introduction of knowledge sharing tools/techniques and change in work practice on the retention attitudes of knowledge workers in two context specific environments. Problems relating to the retention of knowledge workers are not confined to Ireland and are shown in this project to be a global phenomenon.

This research project is based on a knowledge audit of core knowledge workers/assets in two context specific environments …

Detailed Comparative Analysis Of Pesq And Visqol Behaviour In The Context Of Playout Delay Adjustments Introduced By Voip Jitter Buffer Algorithms, Andrew Hines, Peter Pocta, Hugh Melvin

Conference papers

The default best-effort Internet presents significant challenges for delay-sensitive applications such as VoIP. To cope with non determinism, receiver playout strategies are utilised in VoIP applications that adapt to network condition. Such strategies can be divided into two different groups, namely per-talkspurt and per-packet. The former make use of silence periods within natural speech and adapt such silences to track network conditions, thus preserving the integrity of active speech talkspurts. Examples of this approach are described in [1, 2]. Per packet strategies are different in that adjustments are made both during silence periods and during talkspurts by time-scaling of packets, …

Geotechnical Technique To Strengthen Traditional I-Walls Through The Use Of Composite Material, Jimmy Irby Jackson

Electronic Theses and Dissertations

On Monday, August 29, 2005, Hurricane Katrina struck the southern gulf coast of the United States. Hurricane Katrina produced record high amounts of surge water along the coastal regions, that over topped and eroded levees and flood walls, inevitably flooding the entire city of New Orleans. After Hurricane Katrina, the Department of Homeland Security approved a research grant to The University of Mississippi to develop effective but economic technique of strengthening existing I-walls. Using composite materials, a new retrofitting technique was developed to increase the stability of existing I-walls by implementing composite caps. For economical and practical testing, scale models …

Mse Annual Report 2013, Department Of Materials Science And Engineering, Michigan Technological University

Department of Materials Science and Engineering Annual Reports

Table of Contents

• Paul Sanders, Project-Oriented Learning
• A New Way to Prevent Deadly Infections
• 3D Printers for Peace and Progress
• Faculty and Staff News
• Graduate Student Update
• Outreach
• Undergraduate Student News
• Alumni at a Glance

Ankle Impedance And Ankle Angles During Step Turn And Straight Walk: Implications For The Design Of A Steerable Ankle-Foot Prosthetic Robot, Evandro M. Ficanha

Dissertations, Master's Theses and Master's Reports - Open

During locomotion, turning is a common and recurring event which is largely neglected in the current state-of-the-art ankle-foot prostheses, forcing amputees to use different steering mechanisms for turning, compared to non-amputees. A better understanding of the complexities surrounding lower limb prostheses will lead to increased health and well-being of amputees. The aim of this research is to develop a steerable ankle-foot prosthesis that mimics the human ankle mechanical properties. Experiments were developed to estimate the mechanical impedance of the ankle and the ankles angles during straight walk and step turn. Next, this information was used in the design of a …

A Hydro-Climatic Modeling Framework For Adaptive Water Resources Management In The Great Lakes Basin, Rabi Gyawali

Dissertations, Master's Theses and Master's Reports - Open

This dissertation addresses water resources decision making in the Great Lakes Basin by developing a multi-model framework for climate change impact assessment, including integrated climate and hydrologic modeling. Physically based watershed models, using soil moisture accounting and temperature index (degree-day) snowmelt algorithms, are developed, calibrated and validated to simulate baseflow, snowmelt, and surface runoff under historic conditions. Comparison with an existing model of the Great Lakes basin, the NOAA Large Basin Runoff Model (LBRM), showed improvements resulting from the increased spatial resolution and use of a more process-based snow algorithm in the Hydrologic Engineering Center's Hydrologic Modeling System (HECHMS). As …

Assessment Of Seismic Damage Of Buildings And Related Environmental Impacts, Carley A. Feese

Dissertations, Master's Theses and Master's Reports - Open

Sustainable development has only recently started examining the existing infrastructure, and a key aspect of this is hazard mitigation. To examine buildings under a sustainable perspective requires an understanding of a building's life-cycle environmental costs, including the consideration of associated environmental impacts induced by earthquake damage. Damage repair costs lead to additional material and energy consumption, leading to harmful environmental impacts. Merging results obtained from a seismic evaluation and life-cycle analysis for buildings will give a novel outlook on sustainable design decisions. To evaluate the environmental impacts caused by buildings, long-term impacts accrued throughout a building's lifetime and impacts associated …