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2014

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Articles 901 - 930 of 1130

Full-Text Articles in Mechanical Engineering

An Introductory Study Of The Dynamics Of Autorotation For Wind Energy Harvesting, Bilal Salih Jan 2014

An Introductory Study Of The Dynamics Of Autorotation For Wind Energy Harvesting, Bilal Salih

Electronic Theses and Dissertations

Wind turbines have been used for decades to harvest wind energy. They are suitable only to work on close to ground, and have several drawbacks that are related to the availability of the wind and the amount of extracted power compared with the cost of construction. On the other hand, there is an abundant wind power that is available at high altitudes. The wind jet streams at high elevations 8 - 12 kms are pervasive and persistent, and can potentially produce immense wind energy. Even at moderate elevations of 4 - 5 kms, wind power densities are much higher than …


Optimization Of Wind Fence Enclosures For Infrasonic Wind Noise Reduction, Johnpaul Russell Abbott Jan 2014

Optimization Of Wind Fence Enclosures For Infrasonic Wind Noise Reduction, Johnpaul Russell Abbott

Electronic Theses and Dissertations

A large porous wind barrier enclosure has been built and tested to optimize wind noise reduction at infrasonic frequencies between 0.01-10 Hz in order to develop a technology that is simple, cost effective, and improves upon the limitations of pipe and porous hose arrays. The effects of varying the fence's porosity, modifying its top condition and bottom gap, doubling the height and diameter, and adding a secondary wind barrier were investigated. A simple mathematical model which estimates the wind noise measured at the center of the enclosure was derived based on the measured turbulence and velocity profiles measure outside the …


Extremum-Seeking For Nonlinear Discrete-Time Systems With Application To Hcci Engines, H. Zargarzadeh, S. Jagannathan, J. A. Drallmeier Jan 2014

Extremum-Seeking For Nonlinear Discrete-Time Systems With Application To Hcci Engines, H. Zargarzadeh, S. Jagannathan, J. A. Drallmeier

Electrical and Computer Engineering Faculty Research & Creative Works

For many control applications, identifying an optimal operating point by maximizing/minimizing a performance function is important. This paper applies the extremum-seeking method to nonaffine, nonlinear discrete-time systems stabilized by an optimal adaptive controller. First, a novel averaging method is used for the nonlinear discrete-time systems to show that their output unique extrema are stable equilibrium points. Then, a singular perturbation method in discrete time is employed to show that the overall closed loop system will dynamically converge to the extremum. The applicability of this scheme is numerically verified on a Homogeneous Charge Compression Ignition (HCCI) model validated experimentally and expressed …


Nebraska Summary: S948 New Holland T4.115, Nebraska Tractor Test Lab Jan 2014

Nebraska Summary: S948 New Holland T4.115, 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: S944 Case-Ih Farmall 115c, Nebraska Tractor Test Lab Jan 2014

Nebraska Summary: S944 Case-Ih Farmall 115c, 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: S943 Case-Ih Farmall 105c, Nebraska Tractor Test Lab Jan 2014

Nebraska Summary: S943 Case-Ih Farmall 105c, 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: S942 Case-Ih Farmall 95c, Nebraska Tractor Test Lab Jan 2014

Nebraska Summary: S942 Case-Ih Farmall 95c, 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 …


Test 2098:John Deere 8245r, Nebraska Tractor Test Lab Jan 2014

Test 2098:John Deere 8245r, 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 …


Test 2095: Case Ih Steiger 500, Nebraska Tractor Test Lab Jan 2014

Test 2095: Case Ih Steiger 500, 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 …


Test 2094: Case Ih Steiger 470, Nebraska Tractor Test Lab Jan 2014

Test 2094: Case Ih Steiger 470, 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 …


Test 2092a: New Holland T9.435, Nebraska Tractor Test Lab Jan 2014

Test 2092a: New Holland T9.435, 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 …


Test 2090: John Deere 7230r, Nebraska Tractor Test Lab Jan 2014

Test 2090: John Deere 7230r, 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 …


Test 2085: John Deere 7250r, Nebraska Tractor Test Lab Jan 2014

Test 2085: John Deere 7250r, 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 …


Test 2084: John Deere 7270r, Nebraska Tractor Test Lab Jan 2014

Test 2084: John Deere 7270r, 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 …


Test 2083: John Deere 7290r, Nebraska Tractor Test Lab Jan 2014

Test 2083: John Deere 7290r, 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 …


Tomographic Imaging Of Combustion Zones Using Tunable Diode Laser Absorption Spectroscopy (Tdlas), Avishek Guha Jan 2014

Tomographic Imaging Of Combustion Zones Using Tunable Diode Laser Absorption Spectroscopy (Tdlas), Avishek Guha

LSU Doctoral Dissertations

This work concentrates on enabling the usage of a specific variant of tunable diode laser absorption spectroscopy (abbr. TDLAS) for tomogaphically reconstructing spatially varying temperature and concentrations of gases with as few reconstruction artifacts as possible. The specific variant of TDLAS used here is known as wavelength modulation with second harmonic detection (abbr. WMS-2f) which uses the wavelength dependent absorbance information of two different spectroscopic transitions to determine temperature and concentration values. Traditionally, WMS-2f has generally been applied to domains where temperature although unknown, was spatially largely invariant while concentration was constant and known to a reasonable approximation (_x0006_+/- 10% …


Meso-Scale Analysis Of Deformation Induced Heating In Granular Metalized Explosives By Piston Supported Waves, Sunada Srinath Nagamani Chakravarthy Jan 2014

Meso-Scale Analysis Of Deformation Induced Heating In Granular Metalized Explosives By Piston Supported Waves, Sunada Srinath Nagamani Chakravarthy

LSU Doctoral Dissertations

Shock sensitivity of heterogeneous explosive composites is dependent on the formation of hot-spots which are small regions of elevated temperatures within the material. Changes in the initial meso-structure (i.e. packing density, composition, particle size and shapes) of the explosives can significantly alter the hot-spot fields in the material and thereby affect its shock sensitivity. In this study, an explicit, 2D, Lagrangian finite and discrete element technique is used to numerically simulate the deformation induced heating of granular mixtures of explosive (HMX), and metal (Al) particles due to piston supported uniaxial deformation waves (400 ≤ Up ≤ 800 m/s). A number …


Association Of Lean Implementation On Perceived Organizational Maturity Levels Of Managers And Staff In The Public Sector, Patrick Eduardo O'Mara Jan 2014

Association Of Lean Implementation On Perceived Organizational Maturity Levels Of Managers And Staff In The Public Sector, Patrick Eduardo O'Mara

LSU Master's Theses

Extensive research has shown the impact of Lean implementation at the process level of an organization to increase quality, reduce cycle time, and reduce operational costs. However, little research has been done to associate Lean with improvement at the strategic level of an organization. The objectives of the present research were to (a) study the association of Lean implementation with maturity levels of employees (b) study the relationship between Lean implementation in the levels of agreement with cohesion between managers and staff in evaluating perceived current state and desired state of organizational practices (c) identify potential barriers of Lean implementation …


Using A Sleep And Activity Monitor To Operationalize Fatigue Risk Management, Vanessa Bégat Seitz Jan 2014

Using A Sleep And Activity Monitor To Operationalize Fatigue Risk Management, Vanessa Bégat Seitz

LSU Master's Theses

When a person continues to work despite being fatigued, an accident may occur or productivity may decrease. Reducing fatigue related accidents is complicated due to the subjective nature and pervasiveness of the feeling of fatigue. Because finding one universal definition or measure of fatigue is problematic, fatigue is typically measured by a combination of factors such as amount of sleep obtained, physical or cognitive work performed, or sleepiness which can then be related back to a measure of performance. Until recently, sleep measurement was restricted to a lab setting; however, with the emergence of actigraph devices, it is now possible …


Assessing The Effects Of Work Zone Configurations On Drivers' Visual Attention, Karthy Punniaraj Jan 2014

Assessing The Effects Of Work Zone Configurations On Drivers' Visual Attention, Karthy Punniaraj

LSU Master's Theses

This study assessed the effects of two different work zone configurations on driver’s visual attention by eye movement monitoring. A driving simulator study was conducted with thirty participants. Variations in traffic density and warning sign placement distance were added to the merge configurations to simulate the real time situation. A 2 x 2 x 3 within-subjects factorial design was used for this research. The independent variables used in this study were (1) merge configuration [(i) Conventional Lane Merge (CLM) and (ii) Joint Lane Merge (JLM)], (2) traffic density [(i) high and (ii) low] and (3) distance between traffic signs [(i) …


Age, Performance And Retention Interval Effects On Acceptance Of A Consumer Health Information Technology System, Stephen Andrew Ford Jan 2014

Age, Performance And Retention Interval Effects On Acceptance Of A Consumer Health Information Technology System, Stephen Andrew Ford

LSU Master's Theses

The older adult population will continue to place pressure on the financial and resource allocation of the healthcare industry as the over 65 population continues to grow. Health care expenditures to treat the aging population will continue to rise as older adults are more likely to have expensive chronic conditions. The future may lay with Consumer Health Information Technology which may allow the patients to have more control of their treatment schedule and self-management of their health and chronic conditions. However, older adults may exhibit cognitive declines that prohibit the learning and proper use of technology, and this assumption is …


A Parametric Investigation Of A Novel, Modular, Gasketless, Microfluidic Interconnect Using Parallel Superhydrophobic Surfaces, Christopher Ramsey Brown Jan 2014

A Parametric Investigation Of A Novel, Modular, Gasketless, Microfluidic Interconnect Using Parallel Superhydrophobic Surfaces, Christopher Ramsey Brown

LSU Master's Theses

The gasketless microfluidic interconnect has the potential to offer a standardized approach to interconnects between modular microfluidic components. This strategy uses parallel superhydrophobic surfaces (contact angle ≥ 150ᴼ) to passively seal adjacent, concentric, microfluidic ports separated by an air gap using a liquid bridge created between the chips. The parallel superhydrophobic surfaces do not require the addition of a gasket or other additional components so that the assembly process scales favorably with an increasing number of fluidic interconnects. The gasketless seal does not contribute to geometric constraint between the component chips which allows alignment between chips to scale favorably with …


An Experimental Investigation Of Corrosion Fatigue Life Via Thermographic Method, Richard Wayne Purvis Jan 2014

An Experimental Investigation Of Corrosion Fatigue Life Via Thermographic Method, Richard Wayne Purvis

LSU Master's Theses

The effect of prior corrosion fatigue damage on the thermographic response of 1018 low carbon steel is investigated. Specimens were subject to rotating bending fatigue at 38 Hz loading frequency while being exposed to a 3.5% NaCl and distilled water solution. Some specimens were subject to corrosion fatigue for part of their fatigue life and then their thermographic response measured under fatigue in air at 62 Hz loading frequency. Fatigue tests in air with thermographic measurement were performed as a comparison. It was observed that the initial temperature rise after corrosion fatigue fits the previously proposed model for air fatigue, …


A Thermographic Method For Remaining Fatigue Life Prediction Of Welded Joints, Paul Thomas Williams Jan 2014

A Thermographic Method For Remaining Fatigue Life Prediction Of Welded Joints, Paul Thomas Williams

LSU Master's Theses

A non-destructive thermographic technique is adapted and applied to study the fatigue life and behavior of welded specimens made from two different materials. Results show good agreement between experimental predictions of consumed fatigue life and predicted fatigue life. Further, the thermal evolution of the specimens is used to calculate Damage Parameter, which is also used to make fatigue life predictions with promising results. To gain further insight Buckingham Pi theorem is also applied to determine the role of the important parameters involved in a dimensionless form. For this purpose, a series of experiments were performed and used for the analysis …


Fabrication And Enhancement Of Aluminum-Based Microchannel Devices, Paul Joseph Hymel Jan 2014

Fabrication And Enhancement Of Aluminum-Based Microchannel Devices, Paul Joseph Hymel

LSU Master's Theses

Microscale molding replication and transient liquid phase (TLP) bonding were used to fabricate Al-based microchannel heat exchangers (MHEs) and micro gas chromatograph (mGC) columns. Metal-based microchannel heat exchangers often experience corrosion as a result of their operating conditions. To address this problem, an internal anodization method was developed in Al microtubes by pulsing the flow of electrolyte through a microtube when the current dropped below a set value. The anodic aluminum oxide (AAO) films were characterized by scanning electron microscopy (SEM), focused ion beam (FIB) cross sections, and X-ray energy dispersive spectroscopy (EDS) to determine their growth rate and morphology. …


Using Eye-Tracking To Investigate Strategy And Performance Of Expert And Novice Control Room Operators, Christina Marie Koffskey Jan 2014

Using Eye-Tracking To Investigate Strategy And Performance Of Expert And Novice Control Room Operators, Christina Marie Koffskey

LSU Master's Theses

There is lacking research within the Petrochemical Industry that uses eye-tracking to explore the differences between the strategies of expert and novice control room operators as they monitor and address process parameters that could be used to improve novice training programs and interface design. Scan paths and three eye-tracking metrics (Fixation Frequency, Gaze Duration Mean, and Gaze Percentage) were used to investigate the differences in eye behavior of three expert control room operators and six novice students as they monitored and corrected a Crude Refinement simulation. A 2x2x2 mixed factor design was used to explore the effects that expertise (expert …


Minimization Of Transportation, Installation And Maintenance Operations Costs For Offshore Wind Turbines, Tasnim Ibn Faiz Jan 2014

Minimization Of Transportation, Installation And Maintenance Operations Costs For Offshore Wind Turbines, Tasnim Ibn Faiz

LSU Master's Theses

Although it is a sustainable source and there is abundant potential for energy, cost of energy generated from offshore wind is still high compared to other sustainable energy sources. Apart from the manufacturing cost of turbines, cost of energy is significantly affected by costs of transportation and installation operations of wind turbines and maintenance operations of turbine components. Through optimum selection of decision variables, such as turbine installation method and rated power output of each turbine, cost of transportation and installation operations can be minimized. The first model in this study investigates the impact of these decision variables and effect …


Analyses Of Online Monitoring Signals For A Gmaw Process Before And After Improvement, Aniruddha Joshi Jan 2014

Analyses Of Online Monitoring Signals For A Gmaw Process Before And After Improvement, Aniruddha Joshi

LSU Master's Theses

The ability to detect the onset of welding instability is a very powerful tool in welding process monitoring and control. Toward this goal, this study investigates a gas metal arc welding (GMAW) process by analyzing online monitoring signals. Two separate data sets are obtained from the process, which correspond to (a) a stable process after improvement and (b) a relatively unstable process which tends to exhibit spatter and poor weld bead geometry. Voltage, current, wire-feeding speed and line speed signals for both data sets are analysed and features are extracted from the raw signals using different signal processing techniques. Specifically, …


Modelling Of Biomass Gasification Integrated With A Solid Oxide Fuel Cell System, Wayne Doherty Jan 2014

Modelling Of Biomass Gasification Integrated With A Solid Oxide Fuel Cell System, Wayne Doherty

Doctoral

Biomass is of major interest as a renewable energy source in the context of climate change and energy security. Traditional biomass conversion technologies achieve low electrical efficiencies. Biomass gasification (BG) coupled with fuel cells offer higher efficiencies. Gasification is a process in which a carbonaceous fuel is converted to a combustible gas. It occurs when a controlled amount of oxidant is reacted at high temperatures with available carbon in a fuel within a gasifier. Two technologies (circulating fluidised bed air gasification and dual fluidised bed steam gasification) were modelled. Solid oxide fuel cells (SOFCs) are well suited to integration with …


Classification Of Low Velocity Impactors Using Spiral Sensing Of Acousto-Ultrasonic Waves, Chijioke Agbasi Jan 2014

Classification Of Low Velocity Impactors Using Spiral Sensing Of Acousto-Ultrasonic Waves, Chijioke Agbasi

Theses and Dissertations

The non-linear elastodynamics of a flat plate subjected to low velocity foreign body impacts is studied, resembling the space debris impacts on the space structure. The work is based on a central hypothesis that in addition to identifying the impact locations, the material properties of the foreign objects can also be classified using acousto-ultrasonic signals (AUS). Simultaneous localization of impact point and classification of impact object is quite challenging using existing state-of-the-art structural health monitoring (SHM) approaches. Available techniques seek to report the exact location of impact on the structure, however, the reported information is likely to have errors from …