Mechanical Engineering Commons^™

Systems Chemistry And Parrondo’S Paradox: Computational Models Of Thermal Cycling, Daniel C. Osipovitch, Carl Barratt, Pauline M. Schwartz

Chemistry and Chemical Engineering Faculty Publications

A mathematical concept known as Parrondo’s paradox motivated the development of several novel computational models of chemical systems in which thermal cycling was explored. In these kinetics systems we compared the rates of formation of product under cycling temperature and steady-sate conditions. We found that a greater concentration of product was predicted under oscillating temperature conditions. Our computational models of thermal cycling suggest new applications in chemical and chemical engineering systems.

Funboe Factsheet, Getaway Special Team 2009

Reports and Proposals

No abstract provided.

Sides: Space Italian Dressing Experimental Setup, Getaway Special Team 2009

Reports and Proposals

No abstract provided.

Gathering Leadership Momentum Across Great Distances: Creating An Online Community Of Practice, Erin Dini-Davis, Danielle Theiss-White

Library Faculty & Staff Publications

At the 2007 Mountain Plains Library Association Leadership (MPLA) Institute, held in New Mexico, USA, eight academic librarians formed an online multi-state, multigenerational community of practice. MPLA is a twelve-state library association within the United States. Using Google Groups™, the members formed an online environment called the MPLA Community of Practice for continuing development of the leadership skills presented at the Institute. These early-career librarians represent diverse educational backgrounds and work in libraries serving varied populations with differing disciplinary emphases. The group meets monthly with each member preparing and facilitating online discussions, complete with personal assessments, topical readings, and questions. …

Analysis Of Wear Models For Advanced Coated Materials, Simon Montgomery, David Kennedy, Noel O'Dowd

Conference Papers

Tribological tests, mathematical modelling and simulations have been conducted over the last few decades to investigate the nature and effects of mechanical wear in coated and uncoated materials. Mathematical models have been developed and in unison with specifically designed empirical tests, the veracity/capability of these models has been investigated. In more recent cases advanced engineering analysis tools, such as FEA and DOE, are used to further compliment and refine experimental techniques.

Studies have focused on the various wear mechanisms: abrasion, adhesion, erosion, corrosion wear, fatigue wear and also on different combinations of these. The intrinsic importance of the material in …

Fuzzy Optimal Swarm Of Autonomous Aircrafts For Target Determination And Convergence Control System, Zach D. Richards

Electronic Theses and Dissertations

The thesis project proposes analytical and theoretical algorithms for a networked swarm of autonomous vehicles, such as those used in planet exploration, and to be used in target location determination and convergence, an algorithm of this type could be used in an Autonomous Stratospheric Aircraft (ASA), thus having the possibility of being used for the exploration of a planet as well as many other applications. Upon locating an unknown location of a specified target, the algorithm would then swarm and eventually converge upon the location. There are two similar, but fundamentally different algorithms proposed in this project. These algorithms are …

Nebraska Summary: S695 Agco Rt155a, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Heterogeneous Drive Mechanisms For Novel Locomotion In Rough Terrain, Roy Godzdanker

Electronic Theses and Dissertations

The smaller the robot the easier it is for it to access voids in a collapsed structure, however small size brings a host of other problems related to constrained resources. One of the primary constraints on small robots is limited motive power to surmount obstacles and navigate rough terrain. This thesis examines the addition of bulk motive force actuators to existing locomotion platforms and the impact of these heterogeneous actuators on conventional steering methods. The steering methods examined are those associated with skid steered vehicles and differential drive vehicles. In developing the Crabinator, a robot composed of a limbed crawler …

Rembrant: Research On The Effects Of Microgravity On The Brazil Nut Problem, Getaway Special Team 2009

Reports and Proposals

No abstract provided.

Percolation Study Of Nano-Composite Conductivity Using Monte Carlo Simulationpercolation, Jing Bai

Electronic Theses and Dissertations

A Monte Carlo model is developed for predicting electrical conductivity of carbon nanofiber composite materials. The conductive nanofibers are models as both 2D and 3D network of finite sites that are randomly distributed. The percolation behavior of the network is studied using the Monte Carlo method, which leads to the determination of the percolation threshold. The effect of the nanofiber aspect ratio on the critical nanofiber volume rate is investigated in the current model, each of the nanofibers needs five independent geometrical parameters (i.e., three coordinates in space and two orientation angles) for its identification. There are three controlling parameters …

Effect Of Finite Geometry On Solidification Microstructure In Beam-Based Fabrication Of Thin Wall Structures, Satish C. Kuchi

Browse all Theses and Dissertations

With the advent of Rapid Protyping (RP) in the manufacturing industry, many newtechnologies came into development for quick fabrication of materials. One of the most versatile fabrication process among them is additive manufacturing. Laser based manufacturing (LBM) and electron beam manufacturing (EBM) processes use the energy from a laser or electron beam to build up structures layer by layer directly from powdered metals and wire feed stock. It has been determined from previous work that solidification cooling rate and thermal gradients are the important factors for controlling microstructure (grain size and morphology) and resulting mechanical properties of the deposit. The …

Time Relaxed Round Robin Tournament And The Nba Scheduling Problem, Renjun Bao

ETD Archive

This dissertation study was inspired by the National Basketball Association regular reason scheduling problem. NBA uses the time-relaxed round robin tournament format, which has drawn less research attention compared to the other scheduling formats. Besides NBA, the National Hockey League and many amateur leagues use the time-relaxed round robin tournament as well. This dissertation study is the first ever to examine the properties of general time-relaxed round robin tournaments. Single round, double round and multiple round time-relaxed round robin tournaments are defined. The integer programming and constraint programming models for those tournaments scheduling are developed and presented. Because of the …

Wind Flow Induced Vibrations Of Tapered Masts, Ahmad Bani-Hani

ETD Archive

Structural dynamic analyses of elongated masts subjected to various wind speeds are presented in this work. The masts are modeled as vertically supported cantilever beams,with one end fixed to the ground, and the other end free. The external excitation forces acting of the masts are the results of vortex shedding represented by a sinusoidal time dependent functions. The frequencies of these sinusoidal functions are dictated by the Strouhal numbers associated of the flow regimes crossing over the masts. To enhance the vibratory behavior of a typical mast, under the influence of flow induced vibrations,three different mass distributions along the length …

Non-Collocation Problems In Dynamics And Control Of Mechanical Systems, Timothy M. Obrzut

ETD Archive

Characteristics of mechanical systems with non-collocated sensors and actuators are investigated. Transfer function zeros location as a function of sensor position, zero-pole interlacing, and re-location of zeros are discussed in a context of presented examples. Some of the presented examples involving non-collocation are supported by experimental data. A case study involving a high speed machining spindle is examined. The control problems associated with non-collocation are studied along with the methods to solve them

Smart Rotating Machines For Structural Health Monitoring, Dmitry Leonidovich Storozhev

ETD Archive

The objective of this thesis is to explore an innovative approach to the on-line health monitoring of rotating machinery in the presence of structural damage using active magnetic bearings (AMBs). First, the detailed model of the rotor with the breathing transverse crack is developed using finite element method. Next, the experimental data from the rotating magnetically levitated healthy and cracked shafts, under specially designed external excitation force, was collected, analyzed and compared with the computer simulation. The obtained results demonstrate that the presented on-line health monitoring technique is very effective for detection of the structural damage in rotating machinery, and …

Structural And Thermal Analysis Of Flange For Lng Applications, Mayank D. Kalbhor

ETD Archive

Structural and thermal analysis of the flange used in connection with hose for the transportation of LNG was computationally simulated by the method of finite element and probabilistically evaluated in view of the several uncertainties in the performance parameters. The distribution function and sensitivity factors for the maximum stresses were found out. The effect of various random variables including geometry, structural/thermal properties etc on the maximum stresses were studied probabilistically. These results were useful to identify the most critical random variable in order to optimize the design well before it is introduced in the market. This reduces the manufacturing cost …

Structural And Thermal Analysis Of Hose For Lng Applications, Bipin G. Kashid

ETD Archive

Finite element analysis (FEA) of the hose assembly used for transportation of Liquefied natural gas (LNG) has become a powerful tool in predicting the deformation and stress distributions. FEA helps in analyzing the model and optimizing the design in hostile environment. In the present work, computations are made to predict the maximum stresses caused due to structural and thermal effects in the LNG transportation. The analysis leads to the selection of the appropriate materials to be used and to the identification of both the most critical measurements and parameters. Most engineering design methods are deterministic, but in reality, many engineering …

Heat Transfer In Electroosmotic Flow Of Power-Law Fluids In Micro-Channel, Omkareshwar Rao Bakaraju

ETD Archive

The present study examines heat transfer in electro-osmotic flow of power-law fluids in a micro-channel analytically. The boundary layer equations governing the flow of power-law fluids in a micro-channel have been solved. Heat transfer characteristics such as the temperature distribution and Nusselt number are presented for parametric values of electro-kinetic parameter kH(where k-1 is the Debye length and H is semi-channel height of the micro-channel) and Brinkman number. Uniform surface heat flux boundary condition has been considered. The effects of the Brinkman number on the Nusselt number for specific values of the flow behavior index (n) are analytically determined. This …

Test 1955 John Deere 5055e Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Production And Characterization Of Foam Glass From Container Glass Waste, Dina Mohamed Abdel Alim

Archived Theses and Dissertations

No abstract provided.

Pool Boiling Heat Transfer Characteristics Of Nanofluids And Nanocoatings, Sang Muk Kwark

Mechanical and Aerospace Engineering Dissertations - Archive

This research is a qualitative and quantitative investigation to understand the behaviors of nanofluids and nanocoated surfaces during pool boiling heat transfer. The pool boiling behavior of low concentration nanofluids, a mixture created by dispersing nanoparticles in pure water, was experimentally studied over a flat heater. A majority of this work was conducted using Al₂O₃ nanoparticles dispersed in water and some minor work was performed with others (CuO and diamond nanoparticles). Results from this study are consistent with those previously reported in demonstrating that boiling of nanofluids produces a nanocoating on the heater surface, and which in turn increases the …

Cae Tools For Modeling Inertia And Aerodynamic Properties Of An R/C Airplane, Kartik Kiran Parikh

Mechanical and Aerospace Engineering Theses - Archive

Recently there has been significant research in the field of Unmanned Aerial Vehicles (UAV). For efficient deployment and operation of these vehicles, it is imperative that one understands the physical system. This in turn involves one to design efficient control algorithms for implementation in these platforms. Thus we need algorithms and methods that identify the physical system parameters, that in turn can be used to design robust model based control systems. This thesis employs CAE software such as SolidWorks, GAMBIT and FLUENT to calculate the aerodynamic coefficients and moment of inertia. The aerodynamic coefficients are analyzed to understand the sensitivity …

Analysis Of Data Center Cooling Strategies And The Impact Of The Dynamic Thermal Management On The Data Center Efficiency, Veerendra Prakash Mulay

Mechanical and Aerospace Engineering Dissertations - Archive

The power trend for Server systems continues to grow thereby making thermal management of Data centers a very challenging task. Although various configurations exist, the raised floor plenum with Computer Room Air Conditioners (CRACs) providing cold air is a popular operating strategy. The air cooling of data center however, may not address the situation where more energy is expended in cooling infrastructure than the thermal load of data center. Revised power trend projections by ASHRAE TC 9.9 predict heat load as high as 5000W per square feet of compute servers' equipment footprint by year 2010. These trend charts also indicate …

Development Of A Quantum Dot Mediated Thermometry For Minimally Invasive Thermal Therapy, Willard L. Hanson

Mechanical and Aerospace Engineering Dissertations - Archive

Thermally-related, minimally invasive therapies are designed to treat tumors while minimizing damage to the surrounding tissues. Adjacent tissues become susceptible to thermal injury to ensure the cancer is completely destroyed. Destroying tumor cells, while minimizing collateral damage to the surrounding tissue, requires the capacity to control and monitor tissue temperatures both spatially and temporally. Current devices measure the tumor's tissue temperature at a specific location leaving the majority unmonitored. A point-wise application can not substantiate complete tumor destruction. This type of surgery would be more effective if volumetric tissue temperature measurement were available. On this premise, the feasibility of a …

Fabrication Of Plga Nanocomposite Using Two Photon Polymerization, Nikhil Narendra Kavadia

Mechanical and Aerospace Engineering Theses - Archive

The demand of smaller size 3D structures in scale of several nanometers has significantly increased the need of development of new techniques for micro/nano fabrication. Applications of nanomaterial embedded true 3D micro/nano structures in the field of medicine, tissue engineering, scaffolding, drug delivery, antibacterial implants or catheters, modification of textiles and refinement of polymers has opened new areas of research for fabrication of nanocomposites embedded with engineering nanoparticles.A novel fabrication process called two photon polymerization (2PP) is employed for the fabrication of polymeric nanocomposites embedded with PLGA nanoparticles. An ultra short pulsed laser source is used to produce laser at …

Dymore Finite Element Analysis Of The Paired Blade Tiltrotor Conceptual Design And A Comparable Conventional Tiltrotor Design, David Orion Braziel

Mechanical and Aerospace Engineering Theses - Archive

Increasing the solidity of tiltrotors above that of current designs presents challenges associated with control system packaging and control couplings. The paired blade rotor concept addresses these issues by placing two blades that share a pitch link, located for acceptable control coupling, on each of three hub arms.Dymore finite element models of the paired blade rotor and a reference rotor of equal solidity with six evenly spaced blades were developed to identify any potential design flaws of the paired blade rotor associated with rotor frequency placement or control couplings. The finite element rotor models are documented, and the results of …

Numerical Simulation Of Particle Adhesion Dynamics For Applications In Nanomedicine And Biosensing, Samar Shah

Mechanical and Aerospace Engineering Theses - Archive

Multifunctional nanoparticles hold considerable promise as the next generation of medicine that allow for detection of early on-set of diseases and targeted therapy with minimal toxicity. To achieve targeted drug delivery, nanoparticles are usually functionalized with certain ligands (polymers) that bind specifically to a particular type of receptors on the endothelial cell surface, which are expressed exclusively during its diseased state. The ligand coated nanoparticles, loaded with drugs inside, transport in blood stream, and adhere to diseased cells via specific adhesion. However, this whole procedure becomes complicated due to simultaneous involvement of hydrodynamic force, adhesion force and Brownian force. In …

Dynamic Stress From Transverse Impact On Flexural Beams, Joshua Ballard

Mechanical and Aerospace Engineering Theses - Archive

Accurate prediction of stress from impact would be very useful to an engineer in the design and analysis phases of a project. Currently one must resort to finite element analysis and experimentation, both of which have their negatives. Classical hand analysis methods such as the work-energy method overestimate the stress for a weight dropped onto the tip of a cantilevered beam. The goal of this project was to formulate analytical equations that were straightforward and easy to implement that would more accurately predict the dynamic stress in this scenario. Using the already derived equations from the work-energy method, a modification …

Improving Receiver Station-Keeping In Aerial Refueling By Formulating Tanker Motion As Disturbance, Christopher Michael Elliott

Mechanical and Aerospace Engineering Theses - Archive

During aerial refueling operations, the receiver aircraft should hold position within a “refueling box” to maintain the boom-receptacle connection while the tanker aircraft flies in a racetrack maneuver. Prior research work shows, especially in turns, significant difficulty resides in meeting y-deviation requirements, i.e., to stay within the box in the lateral direction. This observation indicates tanker motion as “the biggest disturbance” in turn. The nonlinear equations of motion for the receiver aircraft used in this work are developed in terms of position and orientation states relative to the tanker. Linearization results in a set of equations with tanker motion clearly …

On The Design Of A Biodegradable Poc-Ha Polymeric Cardiovascular Stent, Joonas Ilmari Ponkala

Mechanical and Aerospace Engineering Theses - Archive

The current state of the art in coronary stent technology is mainly populated by metallic stents usually coated with certain drugs to increase biocompatibility, even though experimental biodegradable stents have appeared in the horizon. To design stents from biodegradable polymers one must accurately characterize their mechanical behavior for analysis and optimization.This manuscript presents the process for evaluating the material properties for biodegradable biocompatible POC-HA polymeric composite, techniques for developing the stent models for finite element analysis, and development of material models for finite element analysis. The developed material models were utilized in finite element analysis to evaluate the suitability of …