Mechanical Engineering Commons^™

Nebraska Summary: S1111 John Deere 6145m, 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 …

Nebraska Summary: S1108 John Deere 6110m, 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 …

Nebraska Summary: S1159 John Deere 6250r, 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 …

Experimental And Numerical Investigation Of Pressure Drop In Silicon Carbide Fuel Rod For Application In Pressurized Water Reactors, Ahmed Musafi Abir

Theses and Dissertations

Spacer grids are used in pressurized water reactors (PWRs) fuel assemblies which enhances heat transfer from fuel rods. However, there remain regions of low turbulence in between the spacer grids which contributes to lower heat transfer. To enhance turbulence in these regions surface roughness is applied on the fuel rod walls. Meyer et al [1] used empirical correlations to predict heat transfer and friction factor for artificially roughened fuel rod bundles at high performance light water reactors (LWRs). At present, several types of materials are being used for fuel rod cladding including zircaloy, uranium oxide, etc. But researchers are actively …

Advancing Intersection Management By Utilizing Cost Effective Intelligent Vehicle Concepts And Vehicle-To-Infrastructure Communication Techniques, Bernard O. Ibru

Electronic Theses and Dissertations

Intelligent Transport Systems (ITS) is a growing field of research which focuses on the alleviation of traffic congestion and road accidents caused by miscommunication or confusion of human drivers. Intelligent Intersection Management is a subdivision of ITS which focuses on the seamless management of vehicles arriving at, traversing and exiting intersections to prevent congestion and collision within or around the intersection. This research sought to develop a cost effective method of implementing wireless Vehicle-to-Infrastructure (V2I) communication based Intelligent Intersection Management, by employing the use of 1:4.5 scale version autonomous vehicle prototypes, on a similarly scaled four-way intersection. This was accomplished …

Solar Irradiance Forecasting And Implications For Domestic Electric Water Heating, Christopher Nutter

Electronic Theses and Dissertations

As the effects of burning fossil fuels continues to present its prevalence, the interests in alternative forms of energy is expanding. Within the home, the domestic electrical water heater accounts for approximately 17% of its energy consumption. Reducing the amount of energy required to produce hot water from this thermal system alone can have a significant effect on reducing its carbon footprint. In this presented work, a modeled domestic electrical water heater was supplied photovoltaic and on-grid electrical power to increase its energy efficiency. As photovoltaic (PV) energy is directly related to solar irradiation, it is important to receive accurate …

Thermal Performance Of A Double-Pipe Heat Exchanger With A Koch Snowflake Fractal Design, Anton Gomez

Electronic Theses and Dissertations

Double-pipe heat exchangers are the simplest type of heat exchanger and are widely utilized in industrial applications. The effectiveness of double-pipe heat exchangers can be increased by using various heat transfer enhancement techniques. Passive heat transfer enhancement methods are desirable as they do not require moving components and are easy to manufacture and maintain. The focus of this study is to implement a passive heat transfer enhancement method and to investigate how thermal performance is impacted. Specifically, the inner pipe in a heat exchanger will be modified to have a cross-section in accordance with the Koch snowflake fractal pattern. The …

Electroencephalographic Signal Processing And Classification Techniques For Noninvasive Motor Imagery Based Brain Computer Interface, Md Erfanul Alam

Electronic Theses and Dissertations

In motor imagery (MI) based brain-computer interface (BCI), success depends on reliable processing of the noisy, non-linear, and non-stationary brain activity signals for extraction of features and effective classification of MI activity as well as translation to the corresponding intended actions. In this study, signal processing and classification techniques are presented for electroencephalogram (EEG) signals for motor imagery based brain-computer interface. EEG signals have been acquired placing the electrodes following the international 10-20 system. The acquired signals have been pre-processed removing artifacts using empirical mode decomposition (EMD) and two extended versions of EMD, ensemble empirical mode decomposition (EEMD), and multivariate …

Development Of Guidance Laws For A Reduced Order Dynamic Aircraft Model, Jack W. Brendlinger

Browse all Theses and Dissertations

A set of guidance control laws has been developed for enabling three distinct modes of operation of a reduced order dynamic aircraft model. These include 1) a waypoint following control law, 2) a trajectory tracking control law, and 3) a set of kinematically constrained control laws for reaching a commanded altitude, speed or heading. The formulation of the reduced order model is presented so that the capabilities and limitations of the model are understood, and so that the interface architecture between the controllers and the plant is clearly defined. The controller formulations are then presented, together with sample results. The …

An Automated Controller Design Methodology For Six Degree-Of-Freedom Aircraft Models, Dominic J. Dierker

Browse all Theses and Dissertations

This thesis presents an automated design methodology for development of six degree-of-freedom aircraft controllers. The essential functions required of the controller design are 1) to provide sufficient inner loop compensation to guarantee dynamic stability and acceptable handling qualities over the full flight envelope, and, 2) to enable automated mission following capabilities through implementation of outer loop trackers. A hierarchical control architecture consisting of nested nonlinear dynamic inversion control loops is proposed as a means of achieving these top level objectives. Gain tuning based on an automated linearization methodology is then suggested. Next, an automated optimal control allocation algorithm is tested …

Novel Design And Synthesis Of Nanostructured Electrode Materials For Advanced Lithium Ion Batteries, Zhiqiang Xie

LSU Master's Theses

Nowadays, rechargeable lithium-ion batteries (LIBs) have been widely used as energy storage devices for portable electronic devices. The increasing demand for their emerging applications in hybrid electric vehicles (HEVs) and electric vehicles (EVs) requires us to develop LIBs with higher energy density and power density. However, both the commercial cathode material (LiCoO2) and anode material (graphite) exhibit low specific capacity and poor rate capability, which severely hinder the practical application of lithium-ion batteries for transportation. This thesis mainly includes four research works on novel design and synthesis of nanostructured electrode materials for advanced lithium-ion batteries. To improve the electrochemical performances …

Promotional Effect Of Molten Carbonates On Proton Conductivity And Oxygen Reduction Reaction – An Experimental And Computational Study, Xiaolei Xiong

Theses and Dissertations

Recent research of Solid oxide fuel cells (SOFCs) is aimed to lower the operating temperature to an intermediate temperature (IT) range of 500 to 700^oC, while maintaining a proper performance. This Ph.D. research project investigates the promotional effects of alkaline carbonate eutectics on the proton conductivity of proton conducting electrolytes and cathodic ORR reactivity in SOFCs by both experimental and computational methods. The ionic conductivity of the MC-BZY composite above 500^oC increases with the higher loading of MC. The sample exhibited nearly a factor of two higher conductivity in H₂-containing atmosphere than in air. …

Non-Destructive Evaluation Of Composites: Predictive Ultrasonic Guided-Waves Modeling, Non-Destructive Material Characterization, And The Application To Aerospace Structures, Darun Barazanchy

Theses and Dissertations

To predict guided wave dispersion curves, it is common to use different solution approaches depending on the material type (isotropic or anisotropic) of the medium in which the wave propagates. The two different solution methods are defined in different domains, frequency-phase velocity domain for isotropic materials and wavenumber-phase velocity domain for anisotropic materials. This may lead to difficulties and unsatisfying results when predicting the dispersion curves for hybrid laminates which contain both isotropic and anisotropic materials. Therefore, a unified formulation defined in the wavenumber-phase velocity domain to accomodate both isotropic and anisotropic materials, as well as hybrid combinations, is desired. …

Progressive Failure Analysis Of Composite Materials Using The Puck Failure Criteria, Karan Kodagali

Theses and Dissertations

Fiber reinforced composites have been used in various engineering structures and applications especially in naval, automotive, aeronautical and sports industries. These composite materials generally exhibit brittle damage behavior. The anisotropy in the material and different kinds of failure mechanisms make it difficult to accurately characterize the behavior of composite materials. The present work aims to verify and apply the Puck Failure Criteria using the commercially available finite element package ABAQUS by writing a user-material subroutine in FORTRAN. The model is implemented with different post failure degradation schemes.

In the present work, the progressive failure on composite materials in analyzed using …

Enhanced Dropwise Condensation Via Wettability Contrast Mechanism, Mohammad Alwazzan

Theses and Dissertations

Condensation heat transfer performance can be improved by many methods including the most common used method, which is by increasing the droplet removal rate of the condensing surface. Commonly, this approached can be achieved by promoting a dropwise condensation mode in which super/hydrophobic coatings can be applied on the entire condenser surface to reduce the surface wettability degree. In this dissertation, two main approaches were adapted to enhance the condensation heat transfer performance of the condensing surface via wettability contrast mechanism. Three approaches of investigation were performed to better understand such dropwise condensation promoter methods.

In the first part, alternative …

Wrinkling Of Functionally Graded Sandwich Structures Subject To Biaxial And In-Plane Shear Loads, Harold Costa

Masters Theses

"Benefits of a functionally graded core increasing wrinkling stability of sandwich panels have been demonstrated in a recent paper [1] where a several-fold increase in the wrinkling stress was observed, without a significant weight penalty, using a stiffer core adjacent to the facings. In the present paper wrinkling is analyzed in case where the facings are subject to biaxial compression and/or in-plane shear loading and the core is arbitrary graded through-the-thickness. Two issues addressed are the effect of biaxial or in-plane shear loads on wrinkling stability of panels with both graded and ungraded core and the verification that functional grading …

Manufacturing Of Advanced Continuous Fiber Reinforced Composites For High Temperature Applications, James Robert Nicholas

Doctoral Dissertations

"New resin systems have enabled composites to be considered as attractive alternatives in structural applications that require material to be stronger, lighter and/or more resilient to environmental effects. The current work is on the development of processes to produce continuous fiber reinforced materials from two state of the art resin systems. Two processes were developed to produce continuous fiber reinforced ceramic materials from a preceramic polymer. The first was a vacuum forming process developed using the out-of-autoclave polymer composite manufacturing technique in conjunction with the polymer infiltration and pyrolysis process to produce ceramic composite material of zirconium diboride-silicon carbide reinforced …

Volumetric Error Compensation For 5-Axis Machine Tools, Jennifer Ruth Creamer

Doctoral Dissertations

"This work presents a geometric error compensation method for large 5-axis machine tools. The compensation method presented here uses tool tip measurements recorded throughout the axis space to construct a position-dependent geometric error model that can easily be used for error compensation. The measurements are taken using a laser tracker, permitting rapid error data gathering at most locations in the axis space. First two model types are compared for generating table-based error compensation and experimental results are presented. Table-based compensation is then extended to machine tool controller types with restrictions on the number or combination of compensation tables using an …

Fundamental Principles Of Tremor Propagation In The Upper Limb, Andrew D. Davidson, Steven Knight Charles

Faculty Publications

Although tremor is the most common movement disorder, there exist few effective tremor-suppressing devices, in part because the characteristics of tremor throughout the upper limb are unknown. To clarify, optimally suppressing tremor requires a knowledge of the mechanical origin, propagation, and distribution of tremor throughout the upper limb. Here we present the first systematic investigation of how tremor propagates between the shoulder, elbow, forearm, and wrist. We simulated tremor propagation using a linear, time-invariant, lumped-parameter model relating joint torques and the resulting joint displacements. The model focused on the seven main degrees of freedom from the shoulder to the wrist …

Extending The Upper Temperature Range Of Microchip Gas Chromatography Using A Heater/Clamp Assembly, Abhijit Ghosh, Jacob E. Johnson, Johnathan G. Nuss, Brittany A. Stark, Aaron R. Hawkins, Luke T. Tolley, Brian D. Iverson, H. Dennis Tolley, Milton L. Lee

Faculty Publications

Miniaturization of gas chromatography (GC) instrumentation is of interest because it addresses current and future issues relating to compactness, portability and field application. While incremental advancements continue to be reported in microchip GC, the current performance is far from acceptable. This lower performance compared to conventional GC is due to factors such as pooling of the stationary phase in corners of non-cylindrical channels, adsorption of sensitive compounds on incompletely deactivated surfaces, shorter column lengths and less than optimum interfacing to injector and detector. In this work, a microchip GC system was developed that solves the latter challenge, i.e. microchip interfacing …