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2007

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Articles 391 - 420 of 467

Full-Text Articles in Mechanical Engineering

Test 1900: New Holland Tg 215 Diesel 19-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1900: New Holland Tg 215 Diesel 19-Speed, 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 1906: John Deere 5625 Diesel 9-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1906: John Deere 5625 Diesel 9-Speed, 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 1910: Case-Ih Steiger 480 And Stx 480 Diesel 16-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1910: Case-Ih Steiger 480 And Stx 480 Diesel 16-Speed, 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 1913: Case-Ih Magnum 305 And Mx 305 Diesel 19-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1913: Case-Ih Magnum 305 And Mx 305 Diesel 19-Speed, 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 1916: Case-Ih Magnum 275 Diesel 19-Speed (Chassis S/N Z7rz05000 And Higher), Nebraska Tractor Test Lab Jan 2007

Test 1916: Case-Ih Magnum 275 Diesel 19-Speed (Chassis S/N Z7rz05000 And Higher), 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 …


Composite Sandwich Structure With Grid Stiffened Core, Venkata Dinesh Muthyala Jan 2007

Composite Sandwich Structure With Grid Stiffened Core, Venkata Dinesh Muthyala

LSU Master's Theses

Composite sandwich structures have been widely used in aerospace structures, ship building, infrastructure, etc. due to their light weight and high strength to weight ratio. Traditionally, light-weight core materials such as foam core, truss core, honeycomb core have been used in fabricating sandwich structures with limited success. In this study, a new composite sandwich structure with a hybrid core was proposed, fabricated, tested, and modeled. The hybrid core consists of a fiber reinforced polymer grid skeleton that is filled in by extremely light-weight syntactic foam in the bay areas. The new sandwich structure was manufactured using a new manufacturing process. …


Measurements And Computations Of The Flow In Full-Scale Sugar Evaporative-Crystallizers And In Lab-Scale Models, Luis Fernando Echeverri Jan 2007

Measurements And Computations Of The Flow In Full-Scale Sugar Evaporative-Crystallizers And In Lab-Scale Models, Luis Fernando Echeverri

LSU Doctoral Dissertations

The circulation of massecuite is a key factor in achieving efficient heat transfer and crystallization in sugar evaporative crystallizers, and should be as high as practically possible for recovery, quality, and capacity reasons. This research report presents results on the circulation obtained applying modern experimental and numerical techniques. The main goals are contributing to expand the understanding of the process in sugar crystallizers; developing realistic models for the simulation of the circulation; and studying the effect of different design parameters. The circulation of massecuite is driven by buoyancy force due to density difference between the vapor generated and the surrounding …


Development Of Micropump For Microfluidic Applications, Dong Eun Lee Jan 2007

Development Of Micropump For Microfluidic Applications, Dong Eun Lee

LSU Doctoral Dissertations

This dissertation covers the research work on two types of micropumps, one is based on magnetohydrodynamic (MHD) principle that utilizes Lorentz force for actuation, and the other is based on electrochemical actuation. The AC-type MHD micropump was designed and analyzed as a solution to the bubble formation problem encountered in DC-type MHD micropump. A UV-LIGA process using thick layer of SU-8 negative photoresist was successfully developed to microfabricate the AC MHD micropump. Preliminary studies and tests of the AC MHD micropumps demonstrate that bubble formation was significantly reduced to permit the proper function of the micropump. A continuous flow was …


Micro Injection Fuel/Air Premixer/Combustion, Jian Zhang Jan 2007

Micro Injection Fuel/Air Premixer/Combustion, Jian Zhang

LSU Doctoral Dissertations

Lean premixed (LP) combustion has become the dominant industrial approach to reduce NOx emissions. Homogeneous mixing of lean fuel and air mixtures prevents the presence of undesirable localized regions of near-stoichiometric fuel/air mixtures, thereby allowing a reduction in thermal NOx. A new concept, a multi-point micro injection premixer, is presented in this dissertation. The multi-point micro injection premixer is a porous plate that provides a simple but extremely effective method to mix air and fuel. An array of fuel jets is injected in a direction perpendicular to the plane of the premixer plate into an oncoming counterflow stream of air. …


Design, Fabricaton, And Testing Of A Compact Quasi-Isothermal Prox Reactor Using Micro Heat Exchangers, Curtis Maurice Hebert Jan 2007

Design, Fabricaton, And Testing Of A Compact Quasi-Isothermal Prox Reactor Using Micro Heat Exchangers, Curtis Maurice Hebert

LSU Master's Theses

A two stage PROX reactor with micro heat exchangers was designed, built, and tested to demonstrate the ability to control the temperature in the reactor and improve PROX performance in terms of CO conversion and selectivity. The gas stream was composed of 40% H2, 1% CO, 9% CO2, 0.5% O2, and 49.5% Ar. Metal foams were used to support a 5 wt% Pt/0.5 wt% Fe/γ-Al2O3 catalyst. Two sections of foam catalyst were used with heat exchangers positioned before and after each section. The resulting axial temperature profile of the gas stream …


Experimental Investigation Of Heat Transfer Rate In Micro-Channels, Pritish Ranjan Parida Jan 2007

Experimental Investigation Of Heat Transfer Rate In Micro-Channels, Pritish Ranjan Parida

LSU Master's Theses

Metal-based MHEs are of current interest due to the combination of high heat transfer performance and improved mechanical integrity. Efficient methods for fabrication and assembly of functional metal-based MHEs are essential to ensure the economic viability of such devices. The present study focuses on the results of heat transfer testing of assembled Cu- and Al- based microchannel heat exchanger (MHE) prototypes. Efficient fabrication of Cu- and Al- based high-aspect-ratio microscale structures (HARMS) have been achieved through molding replication using surface engineered, metallic mold inserts. Replicated metallic HARMS were assembled through eutectic bonding to form entirely Cu- and Al- based MHE …


Film Cooling From A Row Of Holes Supplemented With Anti Vortex Holes, Alok Dhungel Jan 2007

Film Cooling From A Row Of Holes Supplemented With Anti Vortex Holes, Alok Dhungel

LSU Master's Theses

Film cooling is a technique employed to protect the external surface of gas turbine blades from the hot mainstream gas by ejecting the internal coolant air through discrete holes or slots at several locations on the blade exterior surface. Passing the coolant through conventional cylindrical holes causes a pair of vortices to form which lifts off the coolant jet instead of letting it adhere to the surface. The present study aims at investigating the enhanced cooling performance caused by addition of anti-vortex holes to the main cylindrical film cooling holes. Both heat transfer coefficient and film cooling effectiveness are determined …


Fabrication Of Perforated Polymer Membranes Using Imprinting Technology, Anish Roychowdhury Jan 2007

Fabrication Of Perforated Polymer Membranes Using Imprinting Technology, Anish Roychowdhury

LSU Master's Theses

The goal of the present study was to fabricate perforated membrane structures in polymers with the pore diameter ranging from 10 ìm down to the sub ìm scale. The perforated membrane structure plays an important role in many biological systems. Thus the ability to reproduce such architecture will help with the study of biological systems by mimicking biological cell membrane-like structures and open new vistas in the study of transport behavior in cell biology and the separation of biological vesicles. Such structures also have potential uses as components in polymer optics and modular micro/nanofluidic devices. Use of polymer substrates is …


Manufacturing And Characterization Of High-Aspect-Ratio Diffusive Micro-Mixers, Vamsidhar Palaparthy Jan 2007

Manufacturing And Characterization Of High-Aspect-Ratio Diffusive Micro-Mixers, Vamsidhar Palaparthy

LSU Master's Theses

In the Ligase Detection Reaction (LDR) technique different chemical reagents of varying concentration are mixed with the by-products of the polymerase chain reaction (PCR) for the detection of low abundant cancer diagnostic markers [1]. An effective micro-mixer which is cheap, durable over a relatively broad range of flows with easy manufacturing is required in this process. This work is aimed at manufacturing mixers according to the required specifications with metrology at every manufacturing process to estimate the limits and tolerances during manufacturing and analyzing their efficiency both numerically and experimentally. An optimum mixer design developed earlier by Maha et.al [2] …


Reactive Multilayer Foils And Their Applications In Joining, Xiaotun Qiu Jan 2007

Reactive Multilayer Foils And Their Applications In Joining, Xiaotun Qiu

LSU Master's Theses

In this study, Ni/Al multilayer foils were fabricated by a cold rolling method. A two-stage reaction process was observed in the reaction-ignition experiment. The phase formation process in the cold rolled foils was studied. The first reaction stage with a slow reaction velocity was the lateral growth of Al3Ni phase at isolated nucleation sites and the subsequent coalescence into a continuous layer. The second reaction stage with a fast reaction velocity was the growth of the Al3Ni layers in the direction normal to the Ni/Al interface until all Al was consumed. Afterwards, Al3Ni reacted with the remaining Ni to form …


Study Of Demolding Process In Thermal Imprint Lithography Via Numerical Simulation And Experimental Approaches, Zhichao Song Jan 2007

Study Of Demolding Process In Thermal Imprint Lithography Via Numerical Simulation And Experimental Approaches, Zhichao Song

LSU Master's Theses

The objective of present study was to analyze the mechanical behavior of polymer resist during the demolding process, such as stress distribution and evolution; distortion and tilt of microstructures in thermal imprint lithography, a new emerging technique in mass production of micro/nanoscale patterns. One of the most challenging technical issues for thermal imprint lithography is the structural damages during demolding process. Thermal stress, adhesion force and friction force all play important roles in determination of the success of demolding and it is crucial to understand the underlying physics in order to optimize the structure and process design. In present study, …


Transcendental Eigenvalue Problems Associated With Vibration, Buckling And Control, Jayaram Subramanian Jan 2007

Transcendental Eigenvalue Problems Associated With Vibration, Buckling And Control, Jayaram Subramanian

LSU Master's Theses

The static and dynamic analysis of structures requires us to obtain solutions of their espective governing differential equations subject to appropriate boundary conditions. The dynamic analysis of non-uniform continuous structures is of primary interest, as most traditional methods take the help of discrete models to analyze them. Well established discrete model methods lead to an algebraic eigenvalue problem, the characteristic equation associated with which is a polynomial. The spectral characteristics of a continuous system nevertheless are represented by transcendental functions and cannot be approximated by polynomials efficiently. Hence finite dimensional discrete models are not capable of predicting the response of …


On The Stress Analysis Of Bimetallic Packing Rings, Eric Richard Lewis Jan 2007

On The Stress Analysis Of Bimetallic Packing Rings, Eric Richard Lewis

LSU Master's Theses

The purpose of this research is to try and understand hypercompressor packing ring failures better with a view of ultimately reducing or even eliminating their occurrences. In order to gain further understanding of packing ring failures, we seek to obtain an appreciation of the stresses they experience during operation. First we consider a conventional simulation of an axisymmetric packing ring and cup subjected to the typical pressure loading conditions experienced by these components when installed in a hypercompressor cylinder. The key locations of interest are along the bimaterial interface, and in particular at the ends of the interface. These ends …


Manufacturing, Testing And Modeling Of Advanced Filament Wound Grid Stiffened Composite Cylinders, Ravi Chaitanya Velamarthy Jan 2007

Manufacturing, Testing And Modeling Of Advanced Filament Wound Grid Stiffened Composite Cylinders, Ravi Chaitanya Velamarthy

LSU Master's Theses

Advanced Grid Stiffened (AGS) structures are a kind of FRP composites that are being extensively used in many engineering fields because of their inherent advantages. Hence it is of utmost importance to understand the basic mechanism of these structures in order to develop better models and to find ways to improve their efficiency. This thesis discusses the manufacturing technology used viz. the filament winding technique to fabricate grid stiffened composite cylinders. A step by step procedure of the fabrication process of grid cylinders is explained. The confinement effectiveness of the AGS cylinders is evaluated by filling them with concrete and …


Test 1898a: Case-Ih Mx 215 And Magnum 215 Diesel 19-Speed, Nebraska Tractor Test Lab Jan 2007

Test 1898a: Case-Ih Mx 215 And Magnum 215 Diesel 19-Speed, 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: S615 Massey Ferguson 7495, Nebraska Tractor Test Lab Jan 2007

Nebraska Summary: S615 Massey Ferguson 7495, 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 …


Thermo-Mechanical Design Of A 100 Ghz Mmic Power Amplifier Using Flip Chip Technology, Sean Cremin Jan 2007

Thermo-Mechanical Design Of A 100 Ghz Mmic Power Amplifier Using Flip Chip Technology, Sean Cremin

Theses

This thesis is concerned with the thermo-mechanical design, thermal modelling and temperature profile measurement of a 100 GHz flip chip bump bonded MMIC medium power amplifier.

Flip chip mounting offers superior RF performance in terms of output power, gain, noise figure and bandwidth. The thermal challenge was to dissipate approximately two watts of DC power from the GaAs MMIC (monolithic microwave integrated circuit) through Au (gold) stud bumps which equates to less then 7% of the total surface area of the die. Infrared thermographic images confirmed that the flip chip MMIC amplifier was functional with all eight FET stages on …


Granular Contact Lubrication: Theory And Experiment, Karim El Kholy Jan 2007

Granular Contact Lubrication: Theory And Experiment, Karim El Kholy

LSU Doctoral Dissertations

This dissertation is devoted to a theoretical and experimental study of the granular contact lubrication, both. The theory is based on the kinetic of the granular material where the granules interact with each other and with the boundary surfaces through instantaneous, binary collisions, characterized by a constant coefficient of restitution. Specifically this study focuses on granular lubrication in Couette flows. A series of simulations is reported and the results show good agreement with several published papers. Also, a theory that ties the true temperature to the grain mobility is developed. The true temperature of a granular material depends on the …


Non-Intrusive Pressure Measurement In Microchannels, Derek Fultz Jan 2007

Non-Intrusive Pressure Measurement In Microchannels, Derek Fultz

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

A non-intrusive interferometric measurement technique has been successfully developed to measure fluid compressibility in both gas and liquid phases via refractive index (RI) changes. The technique, consisting of an unfocused laser beam impinging a glass channel, can be used to separate and quantify cell deflection, fluid flow rates, and pressure variations in microchannels. Currently in fields such as microfluidics, pressure and flow rate measurement devices are orders of magnitude larger than the channel cross-sections making direct pressure and fluid flow rate measurements impossible. Due to the non-intrusive nature of this technique, such measurements are now possible, opening the door for …


Experimental Investigation Of Temperature And Tool Wear In High Speed End-Milling Of Titanium Alloy, Benjamin Nwakile Oguejiofor Jan 2007

Experimental Investigation Of Temperature And Tool Wear In High Speed End-Milling Of Titanium Alloy, Benjamin Nwakile Oguejiofor

Masters Theses

"This thesis presents the results of experimental investigation of temperature and tool wear in high speed end-milling of titanium alloy. The investigation of cutting parameters on temperature in high speed end-milling of thin-walled titanium structure was conducted on Cincinnati Milacron Sabre 750 Vertical Machining Center using a 1/2 Fractional Factorial Design of Experiment with 3 factors at 2 levels each. Data logging of temperature data was carried out using VI logger software. Tool tip temperature at the comers and center of the pocket was estimated. All the factors investigated were found to have a significant effect on workpiece temperature. Radial …


Robust Mechanism Synthesis With Random And Interval Variables, Pavan Kumar Venigella Jan 2007

Robust Mechanism Synthesis With Random And Interval Variables, Pavan Kumar Venigella

Masters Theses

"Robust mechanism synthesis ensures that the performance of a mechanism is not sensitive to uncertainties in the mechanism and its environment. The uncertainties include the dimension variations, installation errors, random input motion, and various external forces. Robust mechanism synthesis is used to minimize the impact of these uncertainties on the mechanism performance. Robust mechanism synthesis has been performed by either a probabilistic approach or a worst case approach. The former approach describes uncertain parameters as random variables while the latter approach treats uncertain parameters as interval variables. In this work, methods are developed for robustness assessment and robust mechanism synthesis …


Empirical Dynamic Modeling And Nonlinear Force Control Of Friction Stir Welding, Xin Zhao Jan 2007

Empirical Dynamic Modeling And Nonlinear Force Control Of Friction Stir Welding, Xin Zhao

Masters Theses

"Current Friction Stir Welding (FSW) process models are mainly concerned with the detailed analysis of material flow, heat generation, etc. and therefore, are computationally intensive. Dynamic models describing the total forces acting on the tool throughout the entire welding process are required for the design of feedback control strategies and improved process planning and analysis. In this thesis, empirical models relating the process parameters (i.e., plunge depth, travel speed, and rotation speed) to the process variables (i.e., axial, path, and normal forces) are developed to describe their dynamic relationships"--Abstract, page iv.


Modeling And Control Of Freeze-Form Extrusion Fabrication, Xiyue Zhao Jan 2007

Modeling And Control Of Freeze-Form Extrusion Fabrication, Xiyue Zhao

Masters Theses

"Freeze-form Extrusion Fabrication (FEF) is an additive manufacturing technique that extrudes ceramic loaded aqueous pastes layer by layer below the paste freezing temperature for component fabrication. As the FEF is aimed at being conducted at low environmental temperatures, down to -20°C, it is necessary to investigate the effect of environmental temperature on the process. The advantages of fabrication at low temperature have been proved by experiments. Comparisons in terms of operation parameters, self-sustaining ability, and system dynamic response were performed at different environmental temperatures ranging from 20°C to -20°C.

It is commonly known in paste extrusion processes that due to …


Adhesion-Delamination Mechanics Of Linear And Axisymmetric Film At Film-Substrate Interface, Ming-Fung Wong Jan 2007

Adhesion-Delamination Mechanics Of Linear And Axisymmetric Film At Film-Substrate Interface, Ming-Fung Wong

Masters Theses

"This thesis is to characterize the thin membrane adhesion-delamination phenomena which occur in biological cells and micro-electro-mechanical systems (MEMS) operation. The delamination of a thin film adhered to a rigid substrate is subjected to the coupling effects of tensile residual stress and interfacial adhesion energy. The adhesion-delamination mechanics is derived using the classical linear elasticity and thermodynamics energy balance. The membrane deformation is here dominated by a mixed plate-bending and membrane-stretching, while the concomitant stress is neglected. An 1-dimensional model is first investigated where a pre-stressed rectangular film clamped at both ends delaminates from a rigid punch of the same …


Selective Laser Sintering Of Stearic Acid-Coated Alumina Ceramic, Jason J. Nolte Jan 2007

Selective Laser Sintering Of Stearic Acid-Coated Alumina Ceramic, Jason J. Nolte

Masters Theses

"The purpose of this research is to develop a process that will enable a Selective Laser Sintering (SLS) machine to create geometrically complex green parts of various sizes that become strong, dense ceramic parts after sintering. This will be applicable to SLS systems already operational in industry, and may offer a more cost-effective, more time-efficient method for producing high-temperature ceramic rapid prototype parts. Alumina was the chosen ceramic for the developmental stage of this research. Fine alumina powder (average particle size of 0.4 µm) was coated with stearic acid, which served as a binder. Green parts were made from this …