Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

Theses and Dissertations

Discipline
Institution
Keyword
Publication Year
File Type

Articles 12571 - 12600 of 19640

Full-Text Articles in Entire DC Network

Foundational Work In Bioelectrochemical Anaerobic Reactor Design With Electron Mediators, Christopher D. Hoeger Mar 2013

Foundational Work In Bioelectrochemical Anaerobic Reactor Design With Electron Mediators, Christopher D. Hoeger

Theses and Dissertations

Bioelectrical reactors (BER) have potential to be utilized in a wide variety of industrial applications. This work explores the kinetics involved with reduction of electron mediators (anthraquinone disulfonate and methyl viologen) in bioelectrical reactors. It also discusses on possible application of BER technology to produce ethanol from CO2 and electricity. It is established that Clostridium ragdahlei is capable of sustaining life and product formation with CO2 as the only carbon source. This means it is theoretically possible to utilize CO2 as he source of carbon and electricity as the source of reducing equivalents for bacterial growth and product formation. A …

Go to article

Evaluation Of The Thorax Of Manduca Sexta For Flapping Wing Micro Air Vehicle Applications, Brian C. Cranston Mar 2013

Evaluation Of The Thorax Of Manduca Sexta For Flapping Wing Micro Air Vehicle Applications, Brian C. Cranston

Theses and Dissertations

The tobacco hornworm hawkmoth (Manduca sexta) provides an excellent model from which to gather knowledge pertaining to the development of a Flapping Wing Micro Air Vehicle (FWMAV). One of the major challenges in design of a FWMAV is the energy demanding nature of low Reynolds number flapping flight. Therefore, an understanding of the power required by the flight muscles to actuate the wings is essential for the design of a FWMAV. The M.sexta wing/thorax mechanism was evaluated as a mechanical system in order to gain insight to the mechanical power required to produce the full natural wing stroke. A unique …

Go to article

Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan Mar 2013

Immobilized Viologen Polymer For Use In Direct Carbohydrate Fuel Cells, Yining Pan

Theses and Dissertations

Glucose and other carbohydrates are some of the most abundant renewable energy sources in the world. The oxidation of carbohydrates in a fuel cell allows their chemical energy to be converted directly into electrical energy. Viologen has been indentified and shows promising ability as an electron-transfer catalyst or mediator for carbohydrate oxidation in an alkaline carbohydrate fuel cell. Building on the previous results, the objective of this work was to develop an immobilization chemistry of viologen onto an electrode and to investigate the catalytic activity for carbohydrate oxidation in direct carbohydrate fuel cells.The immobilization was achieved by electropolymerizing a novel …

Go to article

Molecular Analysis Of The Localization And Function Of Caspase-Like Proteins In Dictyostelium Discoideum And The Parasitic Protozoan Acanthamoeba Castellanii, Entsar Jabbar Saheb Kano Mar 2013

Molecular Analysis Of The Localization And Function Of Caspase-Like Proteins In Dictyostelium Discoideum And The Parasitic Protozoan Acanthamoeba Castellanii, Entsar Jabbar Saheb Kano

Theses and Dissertations

Two novel families of caspase-like proteins, metacaspases and paracaspases, have been discovered but have remained poorly characterized. Metacaspase type-1 (Acmcp) has been identified in Acanthamoeba castellanii , which is an opportunistic protozoan parasite that causes several diseases in humans. On the other hand, paracaspase (Ddpcp) has been found in the protozoan Dictyostelium discoideum . D. discoideum is well-researched model organism that is appropriate for studying these caspase-like proteins. In this study, we investigated the localization and molecular function of metacaspase and paracaspase proteins by over-expressing them in D. discoideum . Separate cell lines over-expressing a GFP-tagged version of the full …

Go to article

Glycoconjugates Prevent Bacterial Dissemination And Cellular Death During B. Cereus/ B. Anthracis Infection, Mohamed Hassen Lahiani Mar 2013

Glycoconjugates Prevent Bacterial Dissemination And Cellular Death During B. Cereus/ B. Anthracis Infection, Mohamed Hassen Lahiani

Theses and Dissertations

Bacillus cereus group species including Bacillus cereus and Bacillus anthracis produce highly resistant spores. Dormant spores can survive for long period in harsh environmental conditions. Spores are engulfed by macrophages. Mammalian macrophages are the first line defenders immune cells through its phagocytic activity. Glycoconjugates (GCs) are a family of synthetic carbohydrates that possesses numerous bactericidal and immunodulatory properties. In my study, I used a multivariate approach to study the effects of GCs on B. cereus and B. anthracis Sterne phagocytosis. During in vitro study, I found that GC1 and GC3 were the best candidates that inhibited B. cereus and B. …

Go to article

Rapid Identification Of Bacteria Using Mass Spectrometry And Spectral Pattern Recognition, Pierre Alusta Mar 2013

Rapid Identification Of Bacteria Using Mass Spectrometry And Spectral Pattern Recognition, Pierre Alusta

Theses and Dissertations

Rapid Identification of Bacteria Using Mass Spectrometry and Spectral Pattern Recognition A novel atmospheric pressure ionization process, namely Direct Impact Ionization (DII), is used to ionize bacteria. Electric discharges impinge on an indentation from underneath a stainless steel wire mesh holding a thin dried film of whole bacterial cells, the analyte. The latter is immersed in (350 oC) hot He gas flow. Biomolecular ions as heavy as 560 m/z are generated. Mass spectra are obtained and extracted with a high degree of reproducibility. A bioinformatic methodology for effective representation of spectral data that incorporates noise reduction was developed for this …

Go to article

Relationship Between The Quality Of Educational Facilities, School Climate, And School Safety Of High School Tenth Graders In The United States, Darnell Bell Mar 2013

Relationship Between The Quality Of Educational Facilities, School Climate, And School Safety Of High School Tenth Graders In The United States, Darnell Bell

Theses and Dissertations

The purpose of the study was to understand the relationships among facility conditions, school climate, and school safety of high school tenth graders in the United States. Previous research on the quality of educational facilities influence on student achievement has varied. Recent research has suggested that the quality of educational facilities may have an influence on student achievement. If a relationship exists between the quality of educational facilities and student achievement, information and insight can be provided to school districts, legislatures and school leaders for creating budgets for facilities plans. Administrators and Students Questionnaires, and the Facilities Checklist of the …

Go to article

3d Digital Image Processing For Biofilm Quantification From Confocal Laser Scanning Microscopy, Jerzy S. Zielinski Mar 2013

3d Digital Image Processing For Biofilm Quantification From Confocal Laser Scanning Microscopy, Jerzy S. Zielinski

Theses and Dissertations

The dramatic increase in number and volume of digital images produced in medical diagnostics, and the escalating demand for rapid access to these relevant medical data, along with the need for interpretation and retrieval has become of paramount importance to a modern healthcare system. Therefore, there is an ever growing need for processed, interpreted and saved images of various types. Due to the high cost and unreliability of human-dependent image analysis, it is necessary to develop an automated method for feature extraction, using sophisticated mathematical algorithms and reasoning. This work is focused on digital image signal processing of biological and …

Go to article

Connect With Me! Research Service-Learning In A Gerontological Setting, Cindy A. Brown Mar 2013

Connect With Me! Research Service-Learning In A Gerontological Setting, Cindy A. Brown

Theses and Dissertations

The goal of this study was to evaluate the training components of the Connect with Me! program which was created specifically for this research service-learning project. Ten graduate students in a Biology and Psychology of Aging class were trained and paired with older adults from a long-term care facility and the community. A quasi-experimental research design measured the effectiveness of the program. Results showed significant improvement in life-review interviewing skills. This thesis is divided into three chapters. Chapter one is a literature review of service-learning and offers a suggestion for expansion of Furco's model. Chapter two describes the Connect with …

Go to article

Studies On Dna Mismatch Repair Proteins As Biomarkers For Heriditary Non-Polyposis Colorectal Cancer, Samar Hassen Mar 2013

Studies On Dna Mismatch Repair Proteins As Biomarkers For Heriditary Non-Polyposis Colorectal Cancer, Samar Hassen

Theses and Dissertations

Colorectal cancer is the second most leading cause of cancer related deaths in the Western countries. Hereditary Non-Polyposis Colorectal Cancer (HNPCC), also known as "Lynch Syndrome", is a genetic disorder that accounts for 5-10 % of all diagnosed colorectal cancers. It is caused by genetic defects in DNA mismatch repair proteins including MLH1 and MSH2. The aim of this PhD dissertation research was to develop a sensitive and reliable diagnostic method to screen patients with this syndrome before they develop colorectal cancer. The current methods to screen HNPCC patients are expensive, time consuming and insensitive. The new method would address …

Go to article

Part I: An Artificial Neural Network Model Of Tuberculosis Patient Data, Part Ii: A Dft Computational Model Of Metal Hydrides, William Orson Griffin Mar 2013

Part I: An Artificial Neural Network Model Of Tuberculosis Patient Data, Part Ii: A Dft Computational Model Of Metal Hydrides, William Orson Griffin

Theses and Dissertations

PART I -- The data of tuberculosis patients and a control group were analyzed with the artificial neural network in order to find genetic factors which inhibit and promote the patient to developing drug resistant tuberculosis. The data came from populations in Kyrgyzstan containing genetic and physical records as well as the type of tuberculosis they had contracted. Three models based on the data were developed: first, a model which differentiates TB from control patients, second, a model which differentiates both TB and control patients, and finally, a model which distinguishes infiltrative from chronic type tuberculosis. Factors which influenced the …

Go to article

A Graphical Approach To Drug Safety And Drug Repositioning, Halil Bisgin Mar 2013

A Graphical Approach To Drug Safety And Drug Repositioning, Halil Bisgin

Theses and Dissertations

The pharmaceutical industry has been experiencing diminishing returns in terms of newly approved drugs over a decade. Limited knowledge of target space and the safety issues that come along with newly discovered compounds have forced pharmaceutical companies, government agencies, and academia to seek more practical solutions. Since there have been several cases of repurposing, research interests have emerged for existing drugs whose pharmacokinetics properties are already known and investigation of their potential to treat other cases has become a new direction in pharmacology. Recently, several in silico methodologies have been developed for drug repositioning. In this study, the same purpose …

Go to article

Power Requirements For Bi-Harmonic Amplitude And Bias Modulation Control Of A Flapping Wing Micro Air Vehicle, Justin R. Carl Mar 2013

Power Requirements For Bi-Harmonic Amplitude And Bias Modulation Control Of A Flapping Wing Micro Air Vehicle, Justin R. Carl

Theses and Dissertations

Flapping wing micro air vehicles (FWMAV) have been a growing field in the research of micro air vehicles, but little emphasis has been placed on control theory. Research is ongoing on how to power FWMAVs where mass is a major area of concern. However, there is little research on the power requirements for the controllers to manipulate the wings of a FWMAV. A novel control theory, BABM, allows two actuators to produce forces and moments in five of the FWMAV's six DOF. Several FWMAV prototypes were constructed and tested on a six-component balance. Data was collected for varying control parameters …

Go to article

Needed Actions Within Defense Acquisitions Based On A Forecast Of Future Mobile Information And Communications Technologies Deployed In Austere Environments, Andrew T. Soine Mar 2013

Needed Actions Within Defense Acquisitions Based On A Forecast Of Future Mobile Information And Communications Technologies Deployed In Austere Environments, Andrew T. Soine

Theses and Dissertations

The purpose of this research was twofold. First, it developed a forecast of future mobile information and communications technologies (ICT) suitable for use by military forces in austere environments in 5-10, 10-20, and beyond 20 years. Secondly, it explored whether or not current acquisitions practices will be adequate to meet the needs of warfighters who depend on mobile ICT. These questions were explored by conducting utilization of the Delphi technique. Eight panelists from within the private sector conducted three rounds of iterative feedback. This research resulted in a technology forecast for the three timeframes aforementioned, and the potential impacts to …

Go to article

An Investigation And Analysis Of The Vestibulo-Ocular Reflex In A Vibration Environment, Daniel J. Uribe Mar 2013

An Investigation And Analysis Of The Vestibulo-Ocular Reflex In A Vibration Environment, Daniel J. Uribe

Theses and Dissertations

Forty years of innovations have greatly improved Helmet-Mounted Displays (HMDs) and their integration into military systems. However, a significant issue with HMDs is the effect of vibration and the associated Vestibulo-Ocular Reflex (VOR). When a human’s head is subject to low-frequency vibration, the VOR stabilizes the eye with respect to objects in the external environment. However, this response is inappropriate in HMDs as the display moves with the user’s head and the VOR blurs the image as it is projected on the human retina. Current compensation techniques suggest increasing the size of displayed graphics or text to compensate for the …

Go to article

Fate Of Malathion In An Activated Sludge Municipal Wastewater Treatment System, Edward B. Walters Mar 2013

Fate Of Malathion In An Activated Sludge Municipal Wastewater Treatment System, Edward B. Walters

Theses and Dissertations

Organophosphate compounds are used as pesticides and in chemical warfare agents such as nerve agents. VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) is one of the most toxic and environmentally persistent of these nerve agents. This research examined the fate of malathion, a pesticide and surrogate of VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate), in bench-scale activated sludge (AS) sequencing batch reactors. Sorption kinetics and sorption equilibrium isotherm experiments indicate that sorption to AS biomass was not a statistically important removal mechanism. However, approximately 90% of the initial 4.25 mg L-1 malathion concentration degraded primarily via heterotrophic activity.

Go to article

Application Of Finite Element To Evaluate Material With Small Modulus Of Elasticity, Boyce H. Dauby Mar 2013

Application Of Finite Element To Evaluate Material With Small Modulus Of Elasticity, Boyce H. Dauby

Theses and Dissertations

This thesis describes the development of a series of models utilizing the commercial finite element suite ABAQUS specifically to apply towards the study of biological tissue. The end goal is to be able to obtain the material properties of the Manducca Sexta, a biological inspiration for flapping wing micro-air vehicles. Two finite element models were used to analyze the results of two prior studies of other researchers. A flat punch elastic model examined boundary effects and confirmed that the point of indentation was far enough removed from the boundary. The hyperelastic spherical indentation experiment examined the effects of coefficient of …

Go to article

Development Of Optimized Piezoelectric Bending Actuators For Use In An Insect Sized Flapping Wing Micro Air Vehicle, Robert K. Lenzen Mar 2013

Development Of Optimized Piezoelectric Bending Actuators For Use In An Insect Sized Flapping Wing Micro Air Vehicle, Robert K. Lenzen

Theses and Dissertations

Piezoelectric bimorph actuators, as opposed to rotary electric motors, have been suggested as an actuation mechanism for flapping wing micro air vehicles (FWMAVs) because they exhibit favorable characteristics such as low weight, rapidly adaptable frequencies, lower acoustic signature, and controllable flapping amplitudes. Research at the Air Force Research Labs and the Air Force Institute of Technology has shown that by using one actuator per wing, up to five degrees of freedom are possible. However, due to the weight constraints on a FWMAV, the piezoelectric bimorph actuators need to be fully optimized to support free flight. This study focused on three …

Go to article

Experimental Characterization Of The Structural Dynamics And Aero-Structural Sensitivity Of A Hawkmoth Wing Toward The Development Of Design Rules For Flapping Wing Micro Air Vehicles, Aaron G. Norris Mar 2013

Experimental Characterization Of The Structural Dynamics And Aero-Structural Sensitivity Of A Hawkmoth Wing Toward The Development Of Design Rules For Flapping Wing Micro Air Vehicles, Aaron G. Norris

Theses and Dissertations

A case is made for why the structures discipline must take on a more central role in the research and design of flapping-wing micro-air-vehicles, especially if research trends continue toward bio-inspired, insect-sized flexible wing designs. In making the case, the eigenstructure of the wing emerges as a key structural metric for consideration. But with virtually no structural dynamic data available for actual insect wings, both engineered and computational wing models that have been inspired by biological analogs have no structural truth models to which they can be anchored. An experimental framework is therefore developed herein for performing system identification testing …

Go to article

Finite Element Analysis Of A Highly Flexible Flapping Wing, Justin K. Mason Mar 2013

Finite Element Analysis Of A Highly Flexible Flapping Wing, Justin K. Mason

Theses and Dissertations

Small unmanned aerial systems are being designed to emulate the flapping kinematics of insects and birds which show superior control in slow speed regimes compared to fixed wing or rotorcraft aircraft. The flight of flapping wing vehicles is characterized by aeroelastic effects. Most research has been dedicated towards understanding the aerodynamic side of the aeroelastic response with minimal effort spent towards validating the structural response. A finite element model of a wing from a commercial flapping wing vehicle was created to validate the structural response. Vacuum testing allowed the isolation of the inertial response for a direct comparison to the …

Go to article

Machine Conscious Architecture For State Exploitation And Decision Making, Mark M. Derriso Mar 2013

Machine Conscious Architecture For State Exploitation And Decision Making, Mark M. Derriso

Theses and Dissertations

This research addressed a critical limitation in the area of computational intelligence by developing a general purpose architecture for information processing and decision making. Traditional computational intelligence methods are best suited for well-defined problems with extensive, long-term knowledge of the environmental and operational conditions the system will encounter during operation. These traditional approaches typically generate quick answers (i.e., reflexive responses) using pattern recognition methods. Most pattern recognition techniques are static processes which consist of a predefined series of computations. For these pattern recognition approaches to be effective, training data is required from all anticipated environments and operating conditions. The proposed …

Go to article

Spectral Detection Of Acute Mental Stress With Vis-Swir Hyperspectral Imagery, Elizabeth K. Norvell Mar 2013

Spectral Detection Of Acute Mental Stress With Vis-Swir Hyperspectral Imagery, Elizabeth K. Norvell

Theses and Dissertations

The ability to identify a stressed person is becoming an important aspect across different work environments. Especially in higher-stress career fields, such as first responders and air traffic controllers, mental stress can inhibit a person's ability to accomplish their job. A person's efficiency and psychological state in the work environment can be impeded due to poor mental health. Stress can result in harmful effects on the body, both physically and mentally, including depression, lack of sleep, and fatigue, which can lead to reduced work productivity. Research is being conducted to detect stress in workload-intensive environments. This thesis implements an imaging …

Go to article

Neutron Shielding Effectiveness Of Multifunctional Composite Materials, Anthony D. Marchand Mar 2013

Neutron Shielding Effectiveness Of Multifunctional Composite Materials, Anthony D. Marchand

Theses and Dissertations

Composite materials offer a greater degree of flexibility in design and engineering of specialized space vehicle shielding applications compared to aluminum. A new design for shielding materials has been developed by including specific neutron absorbers and conductive materials into the composite structure. In this research, the neutron shielding capability of two types of custom-designed nanocomposite materials are compared to that of T6061 aluminum.

Go to article

Urgent Aeromedical Evacuation Network Capacity Planning, Scott C. Finkbeiner Mar 2013

Urgent Aeromedical Evacuation Network Capacity Planning, Scott C. Finkbeiner

Theses and Dissertations

Aeromedical Evacuation (AE) has been steadily utilized during Operation Iraqi Freedom and Operation Enduring Freedom. AE is a global enterprise. The current structure of AE is facing changes as forces scale down from operations in Iraq and Afghanistan. AE will, however, continue to be important in its domestic use in the continental USA (CONUS). Current practice is to pull aircraft (e.g. C-17, C-130 or KC-135) from their normal operations to meet Urgent and Priority patient needs when local alternatives are infeasible. An alternative to the current system would be having a centralized "bed-down" location for AE operations that would house …

Go to article

An Examination Of Statistical Rigor Infused Into The Kc-46 Flight Test Program, Sean C. Ritter Mar 2013

An Examination Of Statistical Rigor Infused Into The Kc-46 Flight Test Program, Sean C. Ritter

Theses and Dissertations

The KC-46 program is bringing on-line the replacement aircraft for the KC-135. Although not a new development program, but rather a modification program, there are extensive plans for the flight testing of the KC-46. Recent DoD emphasis mandates the use of statistical design principles for DoD test and evaluation. This project will examine the planned flight test program for KC-46 and reconsider components of that program based on principles of statistical rigor. Of particular focus will be the reliability and maintainability aspects of the flight test program. Current methodology assumes a constant failure rate in all situations, implying that the …

Go to article

Strategic Consolidation Of Medical War Reserve Material (Wrm) Equipment Unit Type Codes (Utc) Assemblages, Chad W. Whitson Mar 2013

Strategic Consolidation Of Medical War Reserve Material (Wrm) Equipment Unit Type Codes (Utc) Assemblages, Chad W. Whitson

Theses and Dissertations

This thesis analyzes the strategic consolidation of medical WRM equipment UTC assemblages located within the contiguous United States. Following a 2003 consolidation assessment, the Air Force Medical Logistics Office (AFMLO) consolidated some of the medical UTCs at three Consolidated WRM Storage and Deployment Centers (CSDC) located at Kelly Field Annex, Travis AFB, and Charleston AFB. While many UTCs were consolidated at that time, currently only 17 of the possible 142 equipment UTC assemblages are entirely consolidated at one of those three locations. After adding three additional bases as possible consolidation locations, this study attempts to minimize the cost of full …

Go to article

Development Of Peptide Nanotube-Modified Biosensors For Gas-Phase Organophosphate Detection, Peter A . Baker Mar 2013

Development Of Peptide Nanotube-Modified Biosensors For Gas-Phase Organophosphate Detection, Peter A . Baker

Theses and Dissertations

Vapor-phase detection of the model organophosphate malathion was achieved using enzymes encapsulated in peptide nanotubes and attached to gold screen-printed electrodes. Malathion was chosen as the model for this experiment because its binding mechanism with acetylcholinesterase (AChE) is identical to its more potent counterparts (such as sarin or VX), but it has an extremely low human toxicity, which makes it both practical and easy to use. The peptide nanotubes had horseradish peroxidase encapsulated inside and were coated with both acetylthiocholine (ASCh) and AChE on the outside. ASCh hydrolysis, which produces thiocholine, was catalyzed by the AChE. The thiocholine was then …

Go to article

Analysis Of Effects Of Organizational Behavior On Evolving System Of Systems Acquisition Programs Through Agent Based Modeling, Klayton S. Bobsein Mar 2013

Analysis Of Effects Of Organizational Behavior On Evolving System Of Systems Acquisition Programs Through Agent Based Modeling, Klayton S. Bobsein

Theses and Dissertations

Every weapon system operates in context with one or more system of systems (SoS). It is the SoS that provides warfighting capability. Each system is managed independently by a program office with program-centric priorities. These systems must be interconnected and interoperable, so the program office must collaborate across the SoS. The SoS are always changing and evolving, triggered by variety of stimuli. Acquisition program offices can be characterized with a set of organizational behaviors that respond to the environment, are influenced by SoS architecture, and can be described by their fitness and contribution to SoS. Using Geert Hofstede's cultural dimensions, …

Go to article

Biodegradation Of An Organophosphate Chemical Warfare Agent Simulant By Activated Sludge With Varying Solid Retention Times, Allen K. Janeczko Mar 2013

Biodegradation Of An Organophosphate Chemical Warfare Agent Simulant By Activated Sludge With Varying Solid Retention Times, Allen K. Janeczko

Theses and Dissertations

This study examined the fate of malathion, a surrogate compound for VX studies, in bench-scale sequencing batch bioreactors being operated under varied solid retention times (SRTs) to simulate the activated sludge process in wastewater treatment facilities. Results show that a constant influent of the malathion will largely be removed. However, the heterotrophic bacteria undergo a stress response which temporarily inhibits malathion removal, the extent of which increases with increasing SRTs. After this stress response takes place, the activated sludge is able to resume a high degree of malathion removal, even with increased influent concentration; however, this is done so at …

Go to article

The Future Of Mobile Information And Communication Technology In Austere Environments: A Command And Control Technology Integration Perspective, James W. Harker Mar 2013

The Future Of Mobile Information And Communication Technology In Austere Environments: A Command And Control Technology Integration Perspective, James W. Harker

Theses and Dissertations

The information and communications technology (ICT) field is undergoing a period of tremendous and rapid change. As ICT develops more rapidly, the United States Air Force needs to remain responsive and adaptive to maintain military advantages. The need to integrate ICT developments sooner than our adversaries prompted an assessment of guidelines evaluating how well the AF is doctrinally positioned from a Command and Control perspective to support integration of emerging ICT. A Delphi Study was commissioned by the 689th CCW to forecast the future of mobile Information and Communication Technology (ICT) in austere environments. Using the ICT forecast data as …

Go to article

First Prev Next Last