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2006

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Articles 31 - 60 of 3928

Full-Text Articles in Engineering

A Case Study Of Inter-Arrival Time Distributions Of Container Ships, Tu-Cheng Kuo, Wen-Chih Huang, Sheng-Chieh Wu, Pei-Lun Cheng Dec 2006

A Case Study Of Inter-Arrival Time Distributions Of Container Ships, Tu-Cheng Kuo, Wen-Chih Huang, Sheng-Chieh Wu, Pei-Lun Cheng

Journal of Marine Science and Technology

Given the recent prevalence of periodical container liners, the applicability of related models of widely applied queuing theory is left in doubt. Since they focus on marine liners, the distribution pattern is always considered to be a deterministic distribution for periodical schedule. In order to investigate the distribution patterns of container liners, observation units are segmented into single shipping liners, single berths, single container terminals and entire ports. The evolution of the ship arrival distribution pattern and the goodness-of-fit test for observation are based on the ship dynamic data of international harbors in Taiwan. This study aims to implement tests …

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Particle Swarm Optimization For Global Optimization Problems, Hsin-Chuan Kuo, Jiang-Ren Chang, Ching-Hsiang Liu Dec 2006

Particle Swarm Optimization For Global Optimization Problems, Hsin-Chuan Kuo, Jiang-Ren Chang, Ching-Hsiang Liu

Journal of Marine Science and Technology

In this paper, the particle swarm optimization (PSO), originated as a simulation of a simplified social system with swarm intelligence and having exploring and exploiting characteristics of the particle swarm, is adopted to deal with the global optimization problems. To begin with, four non-linear two-dimensional functions are adopted as benchmark examples for determining the suitable ranges of parameters in the PSO. It is found that uses of the PSO can make the search quickly converge to the global optimum. Then, several benchmark functions below ten-dimensions are adopted especially for comparisons of search efficiency on the PSO and other algorithms. Results …

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Emergence Of Attached Recirculating Eddy For Flow Around A Circular Cylinder Asymmetrically Placed In A Channel, Tsung-Chan Hsieh, Jiahn-Horng Chen Dec 2006

Emergence Of Attached Recirculating Eddy For Flow Around A Circular Cylinder Asymmetrically Placed In A Channel, Tsung-Chan Hsieh, Jiahn-Horng Chen

Journal of Marine Science and Technology

This study discusses the emergence and development of cylinder-attached recirculating regions appearing in a fully developed flow past a circular cylinder asymmetrically confined between two infinite parallel plates. We employed a finite-volume method with the SIMPLE algorithm to compute the flow fields for various sizes and asymmetrical settings of circular cylinders. Two geometrical parameters, the blockage and asymmetry coefficients, are varied in computations. A series of computations show that the flow evolves a single asymmetrical recirculating region for the Reynolds number beyond some critical value. Its development in length bears a linear relation to the Reynolds number. Its growth rate …

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Web Services Of Mms Applications On Mobile Devices, Cheng-Chih Yang, Cheng-Min Lin Dec 2006

Web Services Of Mms Applications On Mobile Devices, Cheng-Chih Yang, Cheng-Min Lin

Journal of Marine Science and Technology

This study develops the Web services that are applied in Multimedia Message Service (MMS) applications via the Internet and operated by mobile portable devices, such as Personal Digital Assistant (PDA) and cellular phone. First, a MMS system environment and architecture is modeled. Next, the operations and interface of the MMS system is defined by the Web Services Description Language (WSDL) to represent the web services on MMS application system. Finally, two system prototypes are described in this study that includes distance video cam monitor system and GPRS cellular phone MMS sender.

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Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst, Brian L. Critchfield Dec 2006

Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst, Brian L. Critchfield

Theses and Dissertations

Fischer-Tropsch Synthesis (FTS) is a promising technology for the production of ultra-clean fuels and chemical feedstocks from biomass, coal, or natural gas. Iron catalysts are ideal for conversion of coal and biomass. However, precipitated iron catalysts used in slurry-bubble column reactors suffer from high attrition resulting in difficulty separating catalysts from product and increased slurry viscosity. Thus, development of an active and selective-supported iron catalyst to manage attrition is needed. This thesis focuses on the development of a supported iron catalyst and kinetic models of FTS on the catalyst using advanced statistical methods for experimental design and analysis. A high …

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Determinación De La Humedad En Suelos Granulares Utilizando Horno Microondas Y Comparación De Los Resultados Con El Método Tradicional, Claudia Patricia Gámez Camargo, Diana Lorena Hilarión Plazas Dec 2006

Determinación De La Humedad En Suelos Granulares Utilizando Horno Microondas Y Comparación De Los Resultados Con El Método Tradicional, Claudia Patricia Gámez Camargo, Diana Lorena Hilarión Plazas

Ingeniería Civil

No abstract provided.

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Optimizing Production Methods For Artifical Silk Proteins Through Bioreactor And Purification Studies Of Recombinant Proteins Expressed From Pichia Pastoris, Aaron Ramey Dec 2006

Optimizing Production Methods For Artifical Silk Proteins Through Bioreactor And Purification Studies Of Recombinant Proteins Expressed From Pichia Pastoris, Aaron Ramey

All Theses

Advancements in the field of biomaterials are being made to produce an artificial silk fiber. A gene was constructed which utilized components from both the dragline silk of Nephila clavipes and nematode collagen. For this engineered protein, the yeast strain Pichia pastoris was chosen to be the host organism. Previous research has shown P. pastoris to have comparatively low amounts of specific protein productivity. Therefore, this problem must be compensated for by obtaining extremely high cell densities. The main focus of this study was to optimize the fermentation parameters of transgenic yeast cultures within a bioreactor in order to increase …

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Branch Detonation Of A Pulse Detonation Engine With Flash Vaporized Jp-8, John David Slack Dec 2006

Branch Detonation Of A Pulse Detonation Engine With Flash Vaporized Jp-8, John David Slack

Theses and Dissertations

Pulse Detonation Engines (PDE) operating on liquid hydrocarbon fuels are limited to operating frequencies of 35 Hz due to long ignition times from a low energy ignition sources. This study shows ignition time of JP-8 can be nearly eliminated by igniting a thrust tube using a secondary detonation. A counter flow heat exchanger attached to a thrust tube utilized waste heat from the detonation process to heat JP-8 to supercritical conditions. The fuel flash vaporized when injected into the air stream of the engine. A detonation was produced by a spark in a 5 cm diameter, 1.37 m long tube. …

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Elevated Neutral-To-Earth Voltage In Distribution Systems Including Harmonics, Jian Jiang Dec 2006

Elevated Neutral-To-Earth Voltage In Distribution Systems Including Harmonics, Jian Jiang

All Dissertations

The elevated neutral-to-earth voltage (NEV), and the related phenomenon called stray voltage, is analyzed in multigrounded distribution systems. Elevated NEV is typically caused by fundamental frequency currents returning to the source via the neutral conductor and earth. However, harmonic distortion is also found to contribute to elevated NEV. A multiphase harmonic load flow algorithm is developed to examine the effects of various factors on the NEV, including unsymmetrical system configuration, load unbalance and harmonic injection. To fulfill this objective, the system modeling is adapted to include the neutral conductor into the component equivalent circuit. The overhead transmission line is remodeled …

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Design And Implementation Of A Modular Wireless Sensor Network Sniffer, John C. Mceachen, Teo Hong Siang, Georgios Kirykos Dec 2006

Design And Implementation Of A Modular Wireless Sensor Network Sniffer, John C. Mceachen, Teo Hong Siang, Georgios Kirykos

U.S. Navy Research

We present the design and implementation of a wireless packet sniffing application focused on the communications of TinyOS-based sensor networks. This modular, multi-threaded application allows robust analysis of transmitted frames in an easily understood format similar to tcpdump. The underlying software framework is presented and details of the implementation are discussed. Finally, verification of the application is performed using a basic TinyOS application.

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High-Resolution, Real-Time Three-Dimensional Shape Measurement, Song Zhang, Peisen S. Huang Dec 2006

High-Resolution, Real-Time Three-Dimensional Shape Measurement, Song Zhang, Peisen S. Huang

Song Zhang

We describe a high-resolution, real-time 3-D shape measurement system based on a digital fringe projection and phase-shifting technique. It utilizes a single-chip digital light processing projector to project computer-generated fringe patterns onto the object, and a high-speed CCD camera synchronized with the projector to acquire the fringe images at a frame rate of 120frames∕s. A color CCD camera is also used to capture images for texture mapping. Based on a three-step phase-shifting technique, each frame of the 3-D shape is reconstructed using three consecutive fringe images. Therefore the 3-D data acquisition speed of the system is 40frames∕s. With this system, …

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Development Of Fatigue Predictive Models Of Rubberized Asphalt Concrete (Rac) Containing Reclaimed Asphalt Pavement (Rap) Mixtures, Feipeng Xiao Dec 2006

Development Of Fatigue Predictive Models Of Rubberized Asphalt Concrete (Rac) Containing Reclaimed Asphalt Pavement (Rap) Mixtures, Feipeng Xiao

All Dissertations

In recent years, some by-products such as crumb rubber has been used to save money, protect the environment, and extend the life of asphalt pavements. In addition, the utilization of reclaimed asphalt pavement (RAP) is an acceptable practice in many states around the United States and many countries all over the world. However, the use of RAP containing crumb rubber has not been investigated in great detail, so it is essential to explore whether these materials have a positive effect on the fatigue life of asphalt pavement. In general, previous experience shows that the use of RAP has proven to …

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A Multidimensional Scaling And Participatory Design Approach To Classify Open Ended Aircraft Maintenance Data, Kunal Kapoor Dec 2006

A Multidimensional Scaling And Participatory Design Approach To Classify Open Ended Aircraft Maintenance Data, Kunal Kapoor

All Dissertations

The quality assurance data to be analyzed by the web-based surveillance and auditing tool (WebSAT) is both qualitative and quantitative. The forced responses to checklist questions provide a definitive outcome identifying the effectiveness of the four quality assurance work functions. On the other hand, open-ended responses, the second type of response for capturing maintenance errors, are qualitative in nature since they reflect what the auditors and quality assurance representatives observe during their interactions at vendor locations. This research proposes to apply the statistical technique of multidimensional scaling (MDS) and the User centered Design (UCD) method of Participatory Design (PD) to …

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A Comparison Of Optimized Link State Routing With Traditional Ad-Hoc Routing Protocols, Pore Ghee Lye, John C. Mceachen Dec 2006

A Comparison Of Optimized Link State Routing With Traditional Ad-Hoc Routing Protocols, Pore Ghee Lye, John C. Mceachen

U.S. Navy Research

The performance of mobile ad-hoc networks (MANET) is related to the efficiency of the routing protocols in adapting to frequently changing network topology and link status. This paper addresses the issue by comparing the relative performance of three key ad-hoc routing protocols: Destination-sequenced Distance Vector (DSDV), Ad-hoc Ondemand Distance Vector (AODV) and Optimized Link State Routing (OLSR). The protocols are tested based on two scenarios, namely, tactical networks for ships and sensor-based network nodes. Four performance metrics were measured by varying the maximum speed of mobile hosts, network size and traffic load, to assess the routing capability and protocol efficiency. …

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Tannic Acid Crosslinked Collagens And Potential For Breast Tissue Engineering, Cheryl Parzel Dec 2006

Tannic Acid Crosslinked Collagens And Potential For Breast Tissue Engineering, Cheryl Parzel

All Theses

The purpose of this study was to develop and assess a potential key feature in a minimally-invasive breast reconstruction device and to collect information for an in vitro tissue test system. Tannic acid is a hydrolysable plant tannin, and it has been determined that tannic acid functions as a collagen crosslinking agent through both hydrogen bonding mechanisms and hydrophobic effects. Additionally, current research suggests that tannic acid may have anti-tumor properties. Therefore, it has been proposed that tannic acid can be used as an agent to induce apoptotic processes in any transplanted adult stem cells that are inclined to spontaneously …

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Emission Reduction In Small Displacement Diesel Engines Using Cooled Exhaust Gas Recirculation, Chris Simoson Dec 2006

Emission Reduction In Small Displacement Diesel Engines Using Cooled Exhaust Gas Recirculation, Chris Simoson

All Theses

A reduced-order dynamic model is presented and experimentally validated to demonstrate the use of cooled exhaust gas recirculation to alleviate the tradeoff between nitric oxide reduction and performance preservation in a small displacement diesel engine. Exhaust gas recirculation (EGR) is an effective method for internal combustion engine oxides of nitrogen (NOx) reduction, but its thermal throttling diminishes power efficiency. The capacity to cool exhaust gases prior to merging with intake air may achieve the desired pollutant effect while minimizing engine performance losses.
Simulation and experimental results revealed significant NOx reductions throughout all testing scenarios using EGR, but also experienced a …

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Haptics In Robotics And Automotive Systems, Erhun Iyasere Dec 2006

Haptics In Robotics And Automotive Systems, Erhun Iyasere

All Theses

Haptics is the science of applying touch (tactile) sensation and control to interaction with computer applications. The devices used to interact with computer applications are known as haptic interfaces. These devices sense some form of human movement, be it finger, head, hand or body movement and receive feedback from computer applications in form of felt sensations to the limbs or other parts of the human body. Examples of haptic interfaces range from force feedback joysticks/controllers in video game consoles to tele-operative surgery. This thesis deals with haptic interfaces involving hand movements. The first experiment involves using the end effector of …

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Hierarchical State Estimation For Wide Area Power Systems, Srivatsan Lakshminarasimhan Dec 2006

Hierarchical State Estimation For Wide Area Power Systems, Srivatsan Lakshminarasimhan

All Theses

This thesis presents the application of hierarchical state estimation techniques to consolidate the state output of a wide area power system network. In a wide area network a large number of interconnections exist between various utilities of the wide area. Power transactions between areas occur over large distances and hence for better security there is a need to monitor the state of the entire wide area systems. Hierarchical state estimation is preferred over integrated state estimation, due to the reduced computational time.
Using existing state estimators of the member utilities of the wide area in the bottom level of hierarchical …

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Influence Of Temperature And Polymer/ Mold Surface Interactions On Micro-Feature Replication At Ambient Pressure In Micro Injection Molding, Varun Thakur Dec 2006

Influence Of Temperature And Polymer/ Mold Surface Interactions On Micro-Feature Replication At Ambient Pressure In Micro Injection Molding, Varun Thakur

All Theses

This study assesses micro-feature replication at elevated mold temperature and ambient pressure using a variety of polymers. Moldings were made on the surface of stainless steel and silicon wafers containing features as small as 130 nm under isothermal conditions in a heated chamber by allowing polymer to spread over the features at ambient pressure. Feature replication was analyzed via AFM and SEM. Polymer behavior was characterized via melt contact angle and melt viscosity. While feature detail was well replicated, the moldings exhibited poor dimensional accuracy due to shrinkage. In general, polymers with low viscosity and surface tension comparable to the …

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High-Resolution Mapping In Manus Basin, C. Roman, V. Ferrini Dec 2006

High-Resolution Mapping In Manus Basin, C. Roman, V. Ferrini

Christopher N. Roman

Near-bottom seafloor mapping with precisely navigated deep submergence vehicles has become increasingly common in a range of oceanographic settings. Recent mapping efforts at deep-water hydrothermal vent sites have resulted in high-resolution (sub-meter) bathymetry datasets that can be used to identify morphological features associated with volcanic, tectonic, and hydrothermal processes. The resolution of these maps, and our ability to accurately quantify the complex morphologic details of hydrothermal structures has been limited by a number of variables including navigational accuracy, sonar settings (e.g. acoustic wavelength, sonar orientation, ping rate), survey parameters (e.g. altitude, speed), data density, and data processing techniques (e.g. gridding …

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Investigation Of Flow And Microstructure In Rheometric And Processing Flow Conditions For Liquid Crystalline Pitch, Santanu Kundu Dec 2006

Investigation Of Flow And Microstructure In Rheometric And Processing Flow Conditions For Liquid Crystalline Pitch, Santanu Kundu

All Dissertations

A fundamental understanding of flow and its influence on the microstructure is required to obtain carbon materials with desired properties. The objective of this research was to investigate the flow and microstructural behavior of a synthetic mesophase pitch (AR-HP) in rheometric and processing flow conditions. In addition, simulation studies were performed to establish a frame work for modeling the flow behavior of this complex material in different flow situations.
The steady-shear viscosities obtained from a cone-plate rheometer during increasing rate-sweep experiments exhibited a shear-thinning region (Region I) with a slope of about -0.2 and a plateau (Region II) region. The …

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Modeling Of The Transient Behavior Of Heat Pipes With Room-Temperature Working Fluids, Pascal Brocheny Dec 2006

Modeling Of The Transient Behavior Of Heat Pipes With Room-Temperature Working Fluids, Pascal Brocheny

All Dissertations

The heat pipe is a capillary-driven and two-phase flow device, capable of transporting and converting large amounts of energy with minimal losses. As a means of thermal management, uses of heat pipe technology not only include thermal control of satellites and spacecrafts in aerospace applications, but also the cooling of electronic components for ground applications. Recently, there has been a flourishing interest in exploring the use of heat pipe technology in the automotive field. However, in many thermal control applications, heat pipes using room-temperature working fluids, such as water or ammonia, with operating temperatures between 200 K (-73ºC) and 550 …

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Single-Sided Crash Cushion System, John D. Reid, John R. Rohde, Dean L. Sicking Dec 2006

Single-Sided Crash Cushion System, John D. Reid, John R. Rohde, Dean L. Sicking

Department of Mechanical and Materials Engineering: Faculty Publications

A single-sided crash attenuation cushion system having an impact head and three stage energy absorption mechanism. The energy absorbing mechanism has a mandrel for deforming thin-walled tubes in a controlled collapse to absorb impact forces from a colliding vehicle. The third stage of the absorption mechanism includes an additional deformable compressible tube between the fixed-object hazard and the thin walled tubes.

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Development Of A Cellular Fiber Spinning Technology For Regenerative Medicine, Willie Jones Dec 2006

Development Of A Cellular Fiber Spinning Technology For Regenerative Medicine, Willie Jones

All Theses

In order to prove that our textile hollow fiber spinning apparatus was adequate for cellular encapsulation, we confirmed the viability and metabolic activity of green fluorescent protein (GFP) labeled bovine mammary epithelial cells (MAC-Ts) that were encapsulated in either the wall or lumen of alginate fibers. After a 21 day in vitro macroscopic evaluation, no decrease in fluorescence was observed; and it was determined that MAC-Ts encapsulated under both methods produced lactic acid and consumed glucose. Histomorphological analyses revealed that the diameter of the MAC-Ts increased under both encapsulation scenarios, with little to no evidence of cell cluster propagation. Based …

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Dielectric Properties And Method Of Characterizing Ceramic Powders And Multiphase Composites, Ravi Kiran Kota Dec 2006

Dielectric Properties And Method Of Characterizing Ceramic Powders And Multiphase Composites, Ravi Kiran Kota

All Theses

Barium Titanate was the first developed ferroelectric ceramic material and even today it is widely used. It is also a well-known material used for capacitors. The only reason behind a wide range of applications is that barium titanate boasts of high dielectric properties. A phase transition from cubic to tetragonal at normal working temperatures provides enhanced dielectric properties in this electronic material. For any application and design, the most inquired property is the dielectric constant. Predicting the dielectric constant is very much required as it is the pre-requisite. This is the major objective of the present work. To estimate the …

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Use Of Personas For User Interface Design: Results Of Field And Experimental Studies , Pallavi Dharwada Dec 2006

Use Of Personas For User Interface Design: Results Of Field And Experimental Studies , Pallavi Dharwada

All Dissertations

Persona is a fictitious user serving as a role model for designers, helping them make difficult decisions from the users' perspective during the interface design process. This concept, which was introduced by Alan Cooper in 1999, has been found to be a powerful tool for engaging the designers with the users. Although personas do not replace the rich data acquired through user testing, they enhance the interface development process by focusing the designers' attention on the target user until the interface qualifies for testing. Recognizing the benefits of persona, many companies, including the Fortune 500 have embraced this concept as …

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Nonlinear Control Techniques For Robot Manipulators, Nitendra Nath Dec 2006

Nonlinear Control Techniques For Robot Manipulators, Nitendra Nath

All Theses

This Masters thesis describes the design and implementation of control strategies for the following topics of research: i) Whole Arm Grasping Control for Redundant Robot Manipulators, ii) Neural Network Grasping Controller for Continuum Robots and, iii) Coordination Control for Haptic and Teleoperator Systems.

An approach to whole arm grasping of objects using redundant robot manipulators is presented. A kinematic control which facilitates the encoding of both the end-effector position, as well as body self-motion positioning information as a desired trajectory signal for the manipulator joints is developed.

An approach is presented to whole arm grasping control for continuum robots. The …

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Simulation And Characterization Of Tire Nonuniformity-Induced Steering Nibble Vibrations Through Integrated Subsystems Modeling, Derek Mangun Dec 2006

Simulation And Characterization Of Tire Nonuniformity-Induced Steering Nibble Vibrations Through Integrated Subsystems Modeling, Derek Mangun

All Theses

Periodic force variations produced by nonuniform tire/wheel assemblies are known root causes of torsional steering wheel vibrations known as 'nibble'. Previous studies have sought to investigate this issue through modeling or experimentation involving the entire vehicle or specific subsystems, however a direct link between objectively measured tire force variations and the vibration levels perceived by vehicle occupants has yet to be established. Analytical models of a nonuniform tire, double-wishbone suspension system, and rack and pinion steering system are sourced from literature and integrated into a single subsystem-level model validated against experimental data obtained as part of a collaborative effort. The …

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Best Practices For Developing The Engineer's Estimate, Karl Niedzwecki Dec 2006

Best Practices For Developing The Engineer's Estimate, Karl Niedzwecki

All Theses

The research project 'Best Practices for Developing the Engineering Estimate' was executed by Clemson University on behalf of the South Carolina Department of Transportation (SCDOT). The primary objective of this research project was to investigate the strengths and weaknesses of two types of estimating methods being utilized today by state department of transportations (DOT) nationwide. These two types of estimating methods are the unit cost line item approach, which the SCDOT utilizes, and the cost-based estimating approach. This research report identifies accuracy obtained, resources expended, and methodologies utilized when implementing either type of estimating approach. This was done so the …

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Tribological Systems For The Evaluation Of Supercritical Carbon Dioxide Sterilized Ultra-High Molecular Weight Polyethylene, John Desjardins Dec 2006

Tribological Systems For The Evaluation Of Supercritical Carbon Dioxide Sterilized Ultra-High Molecular Weight Polyethylene, John Desjardins

All Dissertations

Polymeric biomaterials are especially susceptible to changes in mechanical and surface material properties as a result of sterilization processes that involve heat, moisture and/or irradiation. This is problematic for polymeric materials used in total joint replacement bearings, as these constructs must retain their superior mechanical and tribological properties over their expected 10-20 years of implantation. A younger more active patient population has now exacerbated this longevity issue with service lifetimes of 20+ years now being expected. Supercritical phase carbon dioxide (SC-CO2) is an industrial solvent that has shown great promise as a sterilizing agent in the food industry. Recently, SC-CO2 …

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