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2008

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Articles 3481 - 3510 of 4190

Full-Text Articles in Engineering

A Surrogate Measure Of Customer Satisfaction In The Manufacture Of Printed Wiring Boards, Adam Y. Maamoun Jan 2008

A Surrogate Measure Of Customer Satisfaction In The Manufacture Of Printed Wiring Boards, Adam Y. Maamoun

Electronic Theses and Dissertations

The objective of this research is to determine and develop a model that is capable of accurately measuring customer satisfaction for different industries and in particularly for the Printed Wiring Boards (PWB) Manufacturers. The new model will incorporate data not being collected or utilized by the survey method of determining customer satisfaction. The method used is a weighted average of satisfaction among several researched categories with percentages that accurately represent the relative importance of multiple facets of the PWB manufacturers customer satisfaction. A very common term in quality assurance is that "What is not measured accurately can not be evaluated …

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Appearance-Driven Material Design, Mark Colbert Jan 2008

Appearance-Driven Material Design, Mark Colbert

Electronic Theses and Dissertations

In the computer graphics production environment, artists often must tweak specific lighting and material parameters to match a mind's eye vision of the appearance of a 3D scene. However, the interaction between a material and a lighting environment is often too complex to cognitively predict without visualization. Therefore, artists operate in a design cycle, where they tweak the parameters, wait for a visualization, and repeat, seeking to obtain a desired look. We propose the use of appearance-driven material design. Here, artists directly design the appearance of reflected light for a specific view, surface point, and time. In this thesis, we …

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Developmemnt Of A Modeling And Simulation Training Needs Model For Selected Defense Acquisition Workforce Communities, Lik Chun Peh Jan 2008

Developmemnt Of A Modeling And Simulation Training Needs Model For Selected Defense Acquisition Workforce Communities, Lik Chun Peh

Electronic Theses and Dissertations

The DoD Modeling and Simulation Steering Committee (M&S SC) identified Modeling and Simulation (M&S) as an educational objective for the Acquisition, Technology and Logistics (AT&L) workforce. Notably, past usages of M&S in system acquisitions for both DoD and commercial industry have demonstrated improvements in efficiency and effectiveness over traditional acquisition techniques. However, to achieve expected and consistent performance by this workforce in these new techniques, the M&S essential skill requirements for this workforce may be extensive. This research aims to validate the content and level of competency in selected M&S tools and technology necessary for consistent workforce performance. The notion …

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Determining Florida Landfill Odor Buffer Distances Using Aermod, Veronica Figueroa Jan 2008

Determining Florida Landfill Odor Buffer Distances Using Aermod, Veronica Figueroa

Electronic Theses and Dissertations

As U.S. landfills continue to grow in size, concerns about odorous gas emissions from landfills are increasing. For states that are expanding in population, such as Florida, odors from landfills are a major concern because new housing developments, needed to accommodate the rapid population growth, are creeping closer and closer to the existing landfills. As homes get closer to landfills, odor complaints are likely to become more frequent, causing landfill managers increased problems with public interactions. Odor buffer zones around landfills need to be established to give municipalities tools to help prevent the building of future homes too close to …

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Production Of Bulk Ceramic Shapes From Polymer Derived Ceramics, Arnold Hill Jan 2008

Production Of Bulk Ceramic Shapes From Polymer Derived Ceramics, Arnold Hill

Electronic Theses and Dissertations

A method has been developed to produce bulk ceramic components from a class of ceramics known as polymer derived ceramics. In the past polymer derived ceramics have been limited to thin film applications or in the fabrication of MEMS devices. The reason being that when the polymer is into a ceramic, large quantities of gas are generated which produce internal pressure that fractures the ceramic components. The method developed here solves that issue by casting into the polymer a 3 dimensional network of polymer fibers in the form of a foam which, during pyrolysis, burns out and leaves a network …

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Laser Enhanced Doping For Silicon Carbide White Light Emitting Diodes, Sachin Bet Jan 2008

Laser Enhanced Doping For Silicon Carbide White Light Emitting Diodes, Sachin Bet

Electronic Theses and Dissertations

This work establishes a solid foundation for the use of indirect band gap semiconductors for light emitting application and presents the work on development of white light emitting diodes (LEDs) in silicon carbide (SiC). Novel laser doping has been utilized to fabricate white light emitting diodes in 6H-SiC (n-type N) and 4H-SiC (p-type Al) wafers. The emission of different colors to ultimately generate white light is tailored on the basis of donor acceptor pair (DAP) recombination mechanism for luminescence. A Q-switched Nd:YAG pulse laser (1064 nm wavelength) was used to carry out the doping experiments. The p and n regions …

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Integration Of A Nanostructure Embedded Thermoresponsive Polymer For Microfluidic Applications, Ghanashyam Londe Jan 2008

Integration Of A Nanostructure Embedded Thermoresponsive Polymer For Microfluidic Applications, Ghanashyam Londe

Electronic Theses and Dissertations

This work describes the modeling, synthesis, integration and characterization of a novel nanostructure embedded thermoresponsive material for microfluidic applications. The innumerable applications of thermoresponsive surfaces in the recent years have necessitated the development of a rigorous mathematical treatment for these surfaces to understand and improve their behavior. An analytical model is proposed to describe the transfer characteristic (variation of contact angle versus temperature) of a unique switchable, nanostructured, thermoresponsive surface consisting of silica nanoparticles and the thermoresponsive polymer, Poly(N-isopropylacrylamide ) (PNIPAAm) which changes its wetting angle upon heating. Important metrics such as the absolute lower critical solution temperature, threshold & …

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An Improved Thermoregulatory Model For Cooling Garment Applications With Transient Metabolic Rates, Johan Westin Jan 2008

An Improved Thermoregulatory Model For Cooling Garment Applications With Transient Metabolic Rates, Johan Westin

Electronic Theses and Dissertations

Current state-of-the-art thermoregulatory models do not predict body temperatures with the accuracies that are required for the development of automatic cooling control in liquid cooling garment (LCG) systems. Automatic cooling control would be beneficial in a variety of space, aviation, military, and industrial environments for optimizing cooling efficiency, for making LCGs as portable and practical as possible, for alleviating the individual from manual cooling control, and for improving thermal comfort and cognitive performance. In this study, we adopt the Fiala thermoregulatory model, which has previously demonstrated state-of-the-art predictive abilities in air environments, for use in LCG environments. We validate the …

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Pressure Losses Experienced By Liquid Flow Through Pdms Microchannels With Abrupt Area Changes, Jonathan Wehking Jan 2008

Pressure Losses Experienced By Liquid Flow Through Pdms Microchannels With Abrupt Area Changes, Jonathan Wehking

Electronic Theses and Dissertations

Given the surmounting disagreement amongst researchers in the area of liquid flow behavior at the microscale for the past thirty years, this work presents a fundamental approach to analyzing the pressure losses experienced by the laminar flow of water (Re = 7 to Re = 130) through both rectangular straight duct microchannels (of widths ranging from 50 to 130 micrometers), and microchannels with sudden expansions and contractions (with area ratios ranging from 0.4 to 1.0) all with a constant depth of 104 micrometers. The simplified Bernoulli equations for uniform, steady, incompressible, internal duct flow were used to compare flow through …

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User-Defined Patterning Of Neural Progenitor Cells On 3d Micropillar Arrays Using Round Cross-Sectional Geometry, Specific Dimen, Andrea Wesser Jan 2008

User-Defined Patterning Of Neural Progenitor Cells On 3d Micropillar Arrays Using Round Cross-Sectional Geometry, Specific Dimen, Andrea Wesser

Electronic Theses and Dissertations

The ability to control stem cell functions, particularly neuronal progenitors, has long since been believed to be the key to successful treatment of neurodegenerative disorders such as Alzheimer's, Parkinson's and accidents involving head trauma. The neurology field calls for many new solutions to address the controlled neural stem cell seeding and placement of cells for neural tissue regeneration. Self-assembled monolayers (SAM) from the alkanethiol group provide a straightforward applicable, reliable treatment for cell adhesion. An ODT/gold treatment was used to adhere the cells to patterned areas, due mainly to a high confluence of cells attracted to it, as well as …

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Severity Analysis Of Driver Crash Involvements On Multilane High Speed Arterial Corridors, Alexis Nevarez-Pagan Jan 2008

Severity Analysis Of Driver Crash Involvements On Multilane High Speed Arterial Corridors, Alexis Nevarez-Pagan

Electronic Theses and Dissertations

Arterial roads constitute the majority of the centerline miles of the Florida State Highway System. Severe injury involvements on these roads account for a quarter of the total severe injuries reported statewide. This research focuses on driver injury severity analysis of statewide multilane high speed arterials using crash data for the years 2002 to 2004. The first goal is to test different ways of analyzing crash data (by road entity and crash types) and find the best method of driver injury severity analysis. A second goal is to find driver, vehicle, road and environment related factors that contribute to severe …

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A Comprehensive Multi-Faceted Approach For Simultaneously Analyzing Organizational Performance Measures Essential For Company Su, Ana Ferreras Jan 2008

A Comprehensive Multi-Faceted Approach For Simultaneously Analyzing Organizational Performance Measures Essential For Company Su, Ana Ferreras

Electronic Theses and Dissertations

Profit, ergonomics, safety, employee morale, quality, efficiency, and productivity are critical components that greatly impact company success within manufacturing organizations. Therefore, it is essential that a valid and reliable systematic approach that encompasses all of these factors be developed for use by top management in today's rapidly changing manufacturing environment. Organizational-level decisions made based upon a single goal or narrow perspective that only considers one of the aforementioned components, such as profit, while ignoring others, such as employee morale, have proven harmful to the long term viability and success of manufacturing companies. Often organizational leaders are not adequately equipped to …

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Preparation And Characterisation Of Stabilized Nafion/Phosphotungstic Acid Composite Membranes For Proton Exchange Membrane Fuel Cell (Pemfc) Automobile Engines, Rohit Agarwal Jan 2008

Preparation And Characterisation Of Stabilized Nafion/Phosphotungstic Acid Composite Membranes For Proton Exchange Membrane Fuel Cell (Pemfc) Automobile Engines, Rohit Agarwal

Electronic Theses and Dissertations

Membrane durability is one of the limiting factors for proton exchange membrane fuel cell (PEMFC) commercialisation by limiting the lifetime of the membrane via electrochemical / mechanical / thermal degradation. Lower internal humidity in the membrane at high temperature ( > 100 °C) and low relative humidity (25-50 %RH) operating conditions leads to increased resistance, lowering of performance and higher degradation rate. One of the promising candidates is composite proton exchange membranes (CPEMs) which have heteropoly acid (HPA) e.g. Phosphotungstic acid (PTA) doped throughout the Nafion® matrix. HPA is primarily responsible for carrying intrinsic water which reduces the external water dependence. …

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Synthesis And Characterization Of Polymer-Derived Porous Sicn Ceramics, Yun Wei Jan 2008

Synthesis And Characterization Of Polymer-Derived Porous Sicn Ceramics, Yun Wei

Electronic Theses and Dissertations

The synthesis and characterization of porous SiCN ceramics produced by the method of polymer-derived ceramics were studied in this work. The polymer-to-ceramic conversion technique is a novel revolution in the methods for fabricating porous materials with controlled morphologies and tailored properties. The porous SiCN ceramics can be successfully prepared from thermal decomposition of polymeric precursors (polysilazane) and the pore former (polyvinyl alcohol (PVA)). The fabrication procedures involved the mixing of the pre-ceramic precursor with appropriate concentration of the PVA, curing, pyrolysis and subsequent PVA removal, leaving pores in the ceramic matrix. The material obtained revealed a homogeneous amorphous microstructure consisting …

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A Comparative Analysis Of Green Roof Designs Including Depth Of Media, Drainage Layer Materials, And Pollution Control Media, Matt Kelly Jan 2008

A Comparative Analysis Of Green Roof Designs Including Depth Of Media, Drainage Layer Materials, And Pollution Control Media, Matt Kelly

Electronic Theses and Dissertations

Population growth has lead to an increase in development and impervious areas in urban settings. Post-development conditions cause several problems for stormwater management such as limited space for stormwater storage systems and the conveyance of pollution picked up by runoff to near by water bodies. Green Roofs with cisterns have been shown to attenuate the peak flow of storm events and reduce the pollution load leaving a site and entering nearby water bodies. The purpose of this research is to expand the available research data on green roofs with cisterns by investigating the water quality and hydrology effects of different …

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Finite Element Modeling Of Tides And Currents Of The Pascagoula River, Qing Wang Jan 2008

Finite Element Modeling Of Tides And Currents Of The Pascagoula River, Qing Wang

Electronic Theses and Dissertations

This thesis focuses on the simulation of astronomic tides of the Pascagoula River. The work is comprised of five steps: 1) Production of a digital elevation model describing the entire Pascagoula River system; 2) Development of an inlet-based, unstructured mesh for inbank flow to better understand the basis of the hydrodynamics within the Pascagoula riverine system. In order to assist in the mesh development, a toolbox was constructed to implement one-dimensional river cross sections into the two-dimensional model; 3) Implementation of a sensitivity analysis of the Pascagoula River two inlet system to examine the inlet effects on tidal propagation; 4) …

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Real-Time Trajectory Planning For Groundand Aerial Vehicles In A Dynamic Environment, Jian Yang Jan 2008

Real-Time Trajectory Planning For Groundand Aerial Vehicles In A Dynamic Environment, Jian Yang

Electronic Theses and Dissertations

In this dissertation, a novel and generic solution of trajectory generation is developed and evaluated for ground and aerial vehicles in a dynamic environment. By explicitly considering a kinematic model of the ground vehicles, the family of feasible trajectories and their corresponding steering controls are derived in a closed form and are expressed in terms of one adjustable parameter for the purpose of collision avoidance. A collision-avoidance condition is developed for the dynamically changing environment, which consists of a time criterion and a geometrical criterion. By imposing this condition, one can determine a family of collision-free paths in a closed …

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Amorphous Phase Formation In Mechanically Alloyed Fe-Based Systems., Satyajeet Sharma Jan 2008

Amorphous Phase Formation In Mechanically Alloyed Fe-Based Systems., Satyajeet Sharma

Electronic Theses and Dissertations

Bulk metallic glasses have interesting combination of physical, chemical, mechanical, and magnetic properties which make them attractive for a variety of applications. Consequently there has been a lot of interest in understanding the structure and properties of these materials. More varied applications can be sought if one understands the reasons for glass formation and the methods to control them. The glass-forming ability (GFA) of alloys can be substantially increased by a proper selection of alloying elements and the chemical composition of the alloy. High GFA will enable in obtaining large section thickness of amorphous alloys. Ability to produce glassy alloys …

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Drive-Based Modeling And Visualization Of Crew Race Strategy And Performance, Jeffrey Cornett Jan 2008

Drive-Based Modeling And Visualization Of Crew Race Strategy And Performance, Jeffrey Cornett

Electronic Theses and Dissertations

Crew race strategy is typically formulated by coaches based on rowing tradition and years of experience. However, coaching strategies are not generally supported by empirical evidence and decision-support models. Previous models of crew race strategy have been constrained by the sparse information published on crew race performance (quarterly 500-meter splits). Empirical research has merely summarized which quarterly splits averaged the fastest and slowest relative to the other splits and relative to the average speed of the other competitors. Video records of crew race world championships provide a rich source of data for those capable and patient enough to mine this …

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Numerical Modeling Of Wave Propagation In Nonlinear Photonic Crystal Fiber, Md. Kaisar Khan Jan 2008

Numerical Modeling Of Wave Propagation In Nonlinear Photonic Crystal Fiber, Md. Kaisar Khan

Electronic Theses and Dissertations

In this dissertation, we propose numerical techniques to explain physical phenomenon of nonlinear photonic crystal fiber (PCF). We explain novel physical effects occurred in PCF subjected to very short duration pulses including soliton. To overcome the limitations in the analytical formulation for PCF, an accurate and efficient numerical analysis is required to explain both linear and nonlinear physical characteristics. A vector finite element based model was developed to precisely synthesize the guided modes in order to evaluate coupling coefficients, nonlinear coefficient and higher order dispersions of PCFs. This finite element model (FEM) is capable of evaluating coupling length of directional …

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Rolls Royce Declares Bankruptcy, John Alfred Heitmann Jan 2008

Rolls Royce Declares Bankruptcy, John Alfred Heitmann

History Faculty Publications

Despite more than sixty years of engineering excellence, Rolls-Royce failed in its attempt to design and manufacture a radically new jet engine to meet contractual obligations with the Lockheed Corp. Consequently, both British and U.S. governments had to step in to avoid an unprecedented economic catastrophe.

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Development And Validation Of A Microcontroller Emissions Model, Shaohua Li Jan 2008

Development And Validation Of A Microcontroller Emissions Model, Shaohua Li

Masters Theses

"A model of the power delivery network of a microcontroller was developed to predict the radiated and conducted emissions from the integrated circuit (IC). A SPICE model of the power delivery network, similar to the ICEM model, was developed for a microcontroller running a typical program and used to predict the noise voltage between the power and return planes of a printed circuit board (PCB).

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Improved Bdfe Using A Priori Information For Turbo Equalization, Jingxian Wu, Sang-Yick Leong, Kah-Ping Lee, Chengshan Xiao, Jan C. Olivier Jan 2008

Improved Bdfe Using A Priori Information For Turbo Equalization, Jingxian Wu, Sang-Yick Leong, Kah-Ping Lee, Chengshan Xiao, Jan C. Olivier

Electrical and Computer Engineering Faculty Research & Creative Works

Turbo equalization improves communication system performance by iteratively exchanging information between soft-input soft-output (SISO) equalizer and SISO channel decoder. The trellis-based maximum a posteriori probability (MAP) algorithm serves as the optimum SISO equalizer for turbo equalization. However, MAP algorithm is unsuitable for systems with large modulation constellation size and severe inter-symbol interference (ISI) due to its prohibitively high computational complexity. In this paper, an improved SISO block decision feedback equalizer (BDFE) is proposed for low complexity turbo equalization. Unlike other sub-optimum equalizers which perform symbol by symbol detection, the proposed equalizer generates the soft output for each data bit by …

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Nebraska Summary: S607 Challenger Mt575b, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S607 Challenger Mt575b, 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 …

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Nebraska Summary: S659 Challenger Mt675c Scr, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S659 Challenger Mt675c Scr, 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 …

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Nebraska Summary: S657 Challenger Mt655c Scr, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S657 Challenger Mt655c Scr, 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 …

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Nebraska Summary: S654 Agco Dt250b, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S654 Agco Dt250b, 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 …

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Nebraska Summary: S687 New Holland T6030 Elite As, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S687 New Holland T6030 Elite As, 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 …

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Nebraska Summary: S680 Case-Ih Maxxum 130 Pro, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S680 Case-Ih Maxxum 130 Pro, 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 …

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Nebraska Summary: S674 New Hollang T6050 Elite Pc, Nebraska Tractor Test Lab Jan 2008

Nebraska Summary: S674 New Hollang T6050 Elite Pc, 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 …

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