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Full-Text Articles in Engineering

Biohydrogen Production By Thermotoga Neapolitana In Agricultural Media, David Morris May 2013

Biohydrogen Production By Thermotoga Neapolitana In Agricultural Media, David Morris

All Theses

In this study the production of hydrogen gas by eubacteria Thermotoga neapolitana was investigated. The organism was grown using varying media of cull peach solids and soybean meal. Hydrogen, co-products, and sugar concentrations were observed and compared.
T. neapolitana grew in medium containing peaches and soybean meal as carbon and nitrogen sources, respectively, and produced hydrogen gas. A standard medium containing glucose and yeast extract produced the most hydrogen at 31.5 mmol H2/L-medium. Withholding the vitamins and minerals from the standard the media had a significant effect on hydrogen production reducing the amount of gas produced to 25.8 mmol H2/L-medium. …


Analytical Evaluation Of Adaptive Transmission Protocols For Markov Models Of Channels With Fading And Moderate Shadowing, Sneha Latha Kottapalli May 2013

Analytical Evaluation Of Adaptive Transmission Protocols For Markov Models Of Channels With Fading And Moderate Shadowing, Sneha Latha Kottapalli

All Theses

Adaptive transmission protocols are often employed to communicate over wireless channels with fading and other time-varying propagation losses. The protocols compensate for the propagation losses and maintain high throughput by adjusting transmission parameters in response to the channel variations. Performance evaluations for practical adaptive transmission protocols typically require simulation of both the time-varying processes and the procedure by which the protocol derives information about the channel quality. In this thesis, we develop an analytical method to evaluate the performance of two practical protocols, an adaptive coding protocol and an adaptive modulation and coding protocol, which rely on statistics derived from …


Laser-Assisted Printing Of Alginate And Cellular Tubes, Jingyuan Yan May 2013

Laser-Assisted Printing Of Alginate And Cellular Tubes, Jingyuan Yan

All Theses

Laser-assisted printing such as laser-induced forward transfer (LIFT) has found increasing biofabrication applications as an orifice-free cell/organ printing approach. Unfortunately, there have been very few studies on its efficacy of three-dimensional (3D) printing performance. In addition, the effects of printing parameters on jet/droplet formation during the printing of Newtonian and non-Newtonian fluids are lacking. Therefore, it is important to investigate its printing process and quality. The resulting knowledge will help to better control the resulting printing quality and feature resolution.
The objective of this study is to investigate the feasibility of laser-assisted 3D printing process and its applicability in making …


Improving R-Value In Brick Systems Using Various Pore-Forming Agents, Graham Shepherd May 2013

Improving R-Value In Brick Systems Using Various Pore-Forming Agents, Graham Shepherd

All Theses

Energy efficiency and energy savings are two topics that have continued to gain momentum over the last decade. This topic is extremely important when it comes to the construction of buildings and homes. Efforts have been ongoing to increase the insulation value of brick systems to hinder the conductive heat transfer through the material. The use of pore-forming agents (PFA’s) have been studied to increase the porosity within a ceramic system, through sacrificial burnout or place–holder method, which leave a residual, defined pore size distribution. This increase in porosity leads to better insulating capabilities and inherently lower conductivity values. In …


An Experimental Study On The Influence That Failure Number, Specialization, And Domain Have On Confidence In Predicting System Failures, Somaiah Thimmaiah May 2013

An Experimental Study On The Influence That Failure Number, Specialization, And Domain Have On Confidence In Predicting System Failures, Somaiah Thimmaiah

All Theses

Design reviews are typically used for three types of design activities: 1) identifying errors, 2) assessing the impact of the errors, and 3) suggesting solutions for the errors. This experimental study focuses on understanding the second issue as it relates to the number of errors considered, the existence of controls, and the level of domain familiarity of the assessor. A set of design failures and associated controls developed for a completed industry sponsored project is used as the experimental design problem. Non-domain individuals (psychology class students), domain generalists (first year engineering students), and domain specialists (graduate mechanical students) are provided …


Parallex File System (Pxfs): Bridging The Gap Between Exascale Processing Capabilities And I/O Performance, Shane Snyder May 2013

Parallex File System (Pxfs): Bridging The Gap Between Exascale Processing Capabilities And I/O Performance, Shane Snyder

All Theses

Due to processors reaching the maximum performance allowable by current technology, architectural trends for computer systems continue to increase the number of cores per processing chip to maximize system performance. Most estimates suggest massively parallel systems will be available within the decade, containing millions of cores and capable of exaFlops of performance. New models of execution are necessary to maximize processor utilization and minimize power costs for these exascale systems. ParalleX is one such execution model, which attempts to address inefficiencies of current execution models by exposing fine-grained parallelism, increasing system utilization using asynchronous workflow, and resolving resource contention through …


A Methodology For Designing Pervious Bicycle Lanes For Stormwater Management, Donald West Iii May 2013

A Methodology For Designing Pervious Bicycle Lanes For Stormwater Management, Donald West Iii

All Theses

Bicycles have proven to be an efficient and reliable form of transportation in urban settings. Therefore, the addition of bicycle lanes into the transportation network could significantly impact and improve the sustainability of our infrastructure by reducing greenhouse emissions and improving the health of individuals who cycle on a regular basis. Pervious pavements are an approved (LID) strategy that could potentially be used to construct these new facilities thereby reducing the quantity of stormwater runoff and improving the water quality. Practicing engineers need both a design aid and research supported methods for designing these improvements before they can be fully …


The Hydraulic Performance Of Perforated Pipe Under-Drains Surrounded By Loose Aggregate, Patrick Murphy May 2013

The Hydraulic Performance Of Perforated Pipe Under-Drains Surrounded By Loose Aggregate, Patrick Murphy

All Theses

Perforated pipes are commonly used in the construction industry for subsurface drains. These subsurface drains are installed to intercept and convey infiltrated runoff or groundwater. One common application of perforated pipe is to provide an under-drain for an infiltration trench or porous pavement best management practice (BMP). Perforated pipe is installed into a trench on a bed of aggregate ranging from 0 to 28 cm thick and, depending on the design objective, is laid flat or on a slope. However, the actual hydraulic performance of these pipes, i.e. the stage storage relationship, is poorly understood. The resulting flow is quite …


The Effect Of Applying Established Color Theory To Packaging When Visible Product And External Labels Exist Simultaneously, Rachel Randall May 2013

The Effect Of Applying Established Color Theory To Packaging When Visible Product And External Labels Exist Simultaneously, Rachel Randall

All Theses

Color is affected by what is around it. A color doesn't necessarily look the same when its placed against two different colored backgrounds (Ryan, William, and Theodore Conover, 2004) Oftentimes, designers are given a blank package and given the task of creating a label or package for the product. What is missing is the product, which can be an integral part of this design process. What is not yet to be determined by current packaging research is how colors work together through the product and package. One way to determine this would be through transparent bottled packages that contain external …


Vibration And Acoustic Properties Of Honeycomb Sandwich Structures Subject To Variable Incident Plane-Wave Angle Pressure Loads, Jiaxue Yan May 2013

Vibration And Acoustic Properties Of Honeycomb Sandwich Structures Subject To Variable Incident Plane-Wave Angle Pressure Loads, Jiaxue Yan

All Theses

Honeycomb structures are widely used in many areas for their material characteristics such as high strength-to-weight ratio, stiffness-to-weight, sound transmission, and other properties. Honeycomb structures are generally constructed from periodically spaced tessellations of unit cells. It can be shown that the effective stiffness and mass properties of honeycomb are controlled by the local geometry and wall thickness of the particular unit cells used. Of particular interest are regular hexagonal (6-sided) honeycomb unit cell geometries which exhibit positive effective Poisson's ratio, and modified 6-sided auxetic honeycomb unit cells with Poisson's ratio which is effectively negative; a property not found in natural …


Measuring Arousal Through Physiological Responses To Packaging Designs: Investigating The Validity Of Electrodermal Activity As A Measure Of Arousal In A Realistic Shopping Environment, Daniel Hutcherson May 2013

Measuring Arousal Through Physiological Responses To Packaging Designs: Investigating The Validity Of Electrodermal Activity As A Measure Of Arousal In A Realistic Shopping Environment, Daniel Hutcherson

All Theses

The validity of electrodermal activity is investigated in the context of packaging design evaluation as a sensitive measure of arousal. Analysts agree that purchasing decisions are subconscious and emotional decisions, contrasted against the popular belief that consumers make purely rational decisions. To understand the personal and rapid character of a consumer's purchasing decisions we must find methods of which to measure and interpret consumer reactions to various packaging designs. Focus groups are discussed as antiquated research methods and new, advanced technologies are outlined as physiological responses. Past literature displays methodological approaches to using electrodermal activity measures in consumer studies, however …


Reverse Engineering: Wimax And Ieee 802.16e, Katherine Cameron May 2013

Reverse Engineering: Wimax And Ieee 802.16e, Katherine Cameron

All Theses

Wireless communications is part of everyday life. As it is incorporated into new products and services, it brings additional security risks and requirements. A thorough understanding of wireless protocols is necessary for network administrators and manufacturers. Though most wireless protocols have strict standards, many parts of the hardware implementation may deviate from the standard and be proprietary. In these situations reverse engineering must be conducted to fully understand the strengths and vulnerabilities of the communication medium.
New 4G broadband wireless access protocols, including IEEE 802.16e and WiMAX, offer higher data rates and wider coverage than earlier 3G technologies. Many security …


Characterization Of Potential Wear Sources In Knee Arthroplasty Prostheses After In Vivo Function, Nicole Durig May 2013

Characterization Of Potential Wear Sources In Knee Arthroplasty Prostheses After In Vivo Function, Nicole Durig

All Theses

Total joint arthroplasty (TJA) is a common procedure generally performed in patients with osteoarthritis. While TJA continues to be a successful treatment for degenerative joint disease, there are many studies that demonstrate wear and its sequelae as the major limitation of joint replacement longevity. Previous studies have shown that wear debris originates from four main locations: articulating surfaces, modular component surfaces, surfaces of fixation, and adjuvant fixation devices. Each of these possible wear sources can initiate the cascade of failure associated with wear-induced osteolysis and lead to subsequent revision surgery. The objective of this thesis is to characterize the in …


Magnetic Manipulation Of Particles And Cells In Ferrofluid Flow Through Straight Microchannels Using Two Magnets, Jian Zeng May 2013

Magnetic Manipulation Of Particles And Cells In Ferrofluid Flow Through Straight Microchannels Using Two Magnets, Jian Zeng

All Theses

Microfluidic devices have been increasingly used in the past two decades for particle and cell manipulations in many chemical and biomedical applications. A variety of force fields have been demonstrated to control particle and cell transport in these devices including electric, magnetic, acoustic, and optical forces etc. Among these particle handling techniques, the magnetic approach provides clear advantages over others such as low cost, noninvasive, and free of fluid heating issues. However, the current knowledge of magnetic control of particle transport is still very limited, especially lacking is the handling of diamagnetic particle. This thesis is focused on the magnetic …


A Model-Free Approach To Vehicle Stability Control, Chinmay Pandit May 2013

A Model-Free Approach To Vehicle Stability Control, Chinmay Pandit

All Theses

This project explored the feasibility of using measured responses of a passenger car together with a fuzzy logic based control algorithm to sense the onset of under-steer (or loss of steering control) and mitigate or eliminate it. The controller is simple and robust and, unlike existing controllers, instead of comparing the vehicle response to that of an idealized model it makes decisions based solely upon the measured response of the car.
Simulations were conducted (using CarSim) of various vehicles executing the skid pad and the double lane change tests to characterize the vehicle behavior. Consistent and qualitatively similar patterns in …