Engineering Commons^™

Development Of A Human Lung Cancer Cytochrome C-Gfp Reporter Cell Line To Study Anti-Cancer Drug Responses In Apoptosis Pathways, Sidra A Piracha

Dissertations and Theses

"Currently chemotherapy and radiotherapy are the most popular methods for cancer treatments after surgery, but lack of specificity and are thus toxic to the healthy human cells. Studies have shown that targeted therapies have been linked to activation of apoptosis signal pathways (cascade of caspases) in cancer cells including intrinsic and extrinsic pathways. One of the major pathways leading to caspase activation involves the release of cytochrome-c from mitochondria. However, in some tumor cells this pathway is inactivated due to the mutation of mitochondria membrane stabilizing proteins (e.g. Bcl-2, Bcl-xL). Therefore, the overall objective of this proposal was to understand …

Technologya Nd Protocolsf Or Translational Researchin Electricals Timulation, Asif Rahman

Dissertations and Theses

"Noninvasive electrical stimulation techniques like transcranial direct currents stimulation (tDCS) have been demonstrated to modulate neural function. Weak constant current is applied via scalp electrodes leading to subthreshold changes in neuron membrane potentials. Neuromodulation of the cortex using direct current (DC) stimulation may be a viable treatment for neurological disorders, enhancing cognitive function as well as facilitating neural plasticity. Theoretically, tDCS can employ many electrodes montages to emphasize directionality, focality, or intensity (Datta 2008, 2009, Dmochowski 2011) but what remains unclear is how these parameters influence cortical neurons considering their orientation and the local synaptic circuit in the region of …

Characterization Of Rheological Properties And Degradation Of Genipin Crosslinked Fibrin Hydrogel For Annulus Repair, Dave Khyati

Dissertations and Theses

No abstract provided.

Effects Of Mild Heating On The Osteogenic Differentiation Of Human Mesenchymal Stem Cells During Inflammation, Kristifor Sunderic

Dissertations and Theses

"Current surgical procedures to treat osteoarthritis have varying degrees of success, but carry inherent risks and a finite life expectancy. A more permanent solution is a treatment that regenerates biologically viable tissue that integrates with the patient and retains functionality. For maximal effectiveness, such a treatment should also repair bone loss known to occur in osteoarthritis and attenuate chronic inflammation that can obstruct healing. Mesenchymal stem cells have great potential to be used as part of a novel therapy for bone and cartilage regeneration. They are a highly regulated, self-renewing population of cells with potent mechanisms to avoid allogeneic rejection, …

Life-Cycle Optimization And Flow Control In A Nickel-Zinc Flow Assisted Battery, Steve Lever

Dissertations and Theses

Nickel-Zinc flow-assisted rechargeable batteries are currently being explored as a potential new generation of large-scale, low-cost energy storage devices. The viability of a commercial nickel-zinc battery has been hindered by the well-known phenomena of dendrite formation and zinc morphology variation over time. Applying electrolyte flow to traditional nickel-zinc battery systems has demonstrated significant life cycle performance improvements by reducing both dendrite formation and morphological variation. It has also been demonstrated that periodic low-current reconditioning discharge further improves cycle life. This thesis examines the effect of eliminating electrolyte flow during discharge of nickel-zinc flow assisted batteries, which would allow a much …

Study Of Air Bubble Injection Into Laminar And Turbulent Water Flow Through An Annular Test Section, Debbrata Das

Dissertations and Theses

Injection of bubbles into a vertical upward flow of water in an annular flow channel was studied experimentally under laminar and turbulent conditions. In order to measure the size and shape of the bubbles, a flow visualization system was set up in a vertical test section with a high speed video camera. A PIV measurement technique was also used to determine laminar and turbulent velocity profiles in the liquid stream. In this study, an efficient image processing methodology was used to obtain the velocity profiles, bubble size, shapes and trajectory at different Reynolds numbers. The measured velocity profiles matched theoretical …

Hydrate Formation Using Dowfax Gemini Surfactants, Franchette Viloria

Dissertations and Theses

"Gas hydrate formation is a stochastic and slow process. However, the use of a small amount of surfactant can speed up the rate of hydrate formation. This work investigates the effect of two Dow surfactants, Dowfax 2A1 and Dowfax C6L, on gas hydrate formation, first by determining the adsorption isotherms via liquid-liquid titration methods, and then investigating the role in methane hydrate formation in a non-stirred batch reactor. Both surfactants have almost similar structure, sharing doubly charged headgroups, but these surfactants express different effects on hydrate formation. 2A1 and C6L both show monolayer formation at around concentration of 1.0 mM; …

Object Detection And Recognition For Visually Impaired People, Shuihua Wang

Dissertations and Theses

"Object detection plays a very important role in many applications such as image retrieval, surveillance, robot navigation, wayfinding, etc. In this thesis, we propose different approaches to detect indoor signage, stairs and pedestrians. In the first chapter we introduce some related work in this field. In the second chapter, we introduced a new method to detect the indoor signage to help blind people find their destination in unfamiliar environments. Our method first extracts the attended areas by using a saliency map. Then the signage is detected in the attended areas by using bipartite graph matching. The proposed method can handle …

Feasibility Analysis Of Estrification Systems With Entrainers, Kang Wook Lee

Dissertations and Theses

(Ethyl Acetate) and IPA (Isopropyl Acetate) production systems are studied in terms of the feasibility analysis. It is not feasible to retrieve pure products by a simple reactive distillation for IPA production system because CCR (Critical Composition Region) covers the entire desired binary edge for IPA system. On the other hand, even though CCR does not cover the entire desired binary edge of the EA system completely, internal reflux ratio (IRR) analysis does not allow the production of the pure product via reactive distillation for EA production system. To overcome the restraints, external entrainers are utilized to take advantage of …

Exploration Of The Endothermic And Exothermic Reactions Of Calcium Oxide And Magnesium Oxide And Design Of A Vessel For A Thermochemical Heat Storage System, Jorge Pulido

Dissertations and Theses

A high temperature Thermal Energy Storage (TES) system has been investigated for use in solar thermal power plants or in vehicles to preheat the engine and/or the cabin in cold weather. The idea is to store surplus thermal energy and then release it on demand to heat a working fluid. The stored heat can be used to generate electricity after sunset or to meet the peak loads. These would lead to an improvement in energy efficiency, reductions in energy imports from foreign sources and total energy-related emissions. The basic operating principle involved in the TES system is a thermochemical reaction …

Fundamental Properties Of Functional Zinc Oxide Nanowires Obtained By Electrochemical Method And Their Device Applications, Athavan Nadarajah

Dissertations and Theses

We report on the fundamental properties and device applications of semiconductor nanoparticles. ZnO nanowires and CdSe quantum dots were used, prepared, characterized, and assembled into novel light-emitting diodes and solar cells. ZnO nanowire films were grown electrochemically using aqueous soluble chloride-based electrolytes as precursors at temperatures below 90° C. Dopants were added to the electrolyte in the form of chloride compounds, which are AlCl₃, CoCl₂, CuCl₂, and MnCl₂. The optical, magnetic, and structural properties of undoped and transition-metal-ion doped ZnO nanowires were explored. Our results indicate that the as-grown nanowire structures have …

Measurement And Modeling Of Passive Surface Mount Devices On Fr4 Substrates, Rahulkumar Sadanand Koche

Dissertations and Theses

Passive components like resistors, capacitors and inductors are used in every electronic system. These are the very basic components which affect the system performance at higher frequencies and it is necessary to understand and model the behavior of these components in a very accurate manner. This work focuses on utilizing Printed Circuit Board (PCB) test boards, or fixtures, made of FR4 for characterizing Surface Mount Device (SMD) components. Agilent's Advanced Design System (ADS) microwave circuit simulation software was used for designing the microstrip transmission lines as well as for generating the layout for manufacturing of the PCB. SMD resistors, capacitors …

Deposition Near Film Cooling Holes On A High Pressure Turbine Vane, Weiguo Ai, Nathan Murray, Thomas H. Fletcher, Spencer Harding, Scott Lewis, Jeffrey P. Bons

Faculty Publications

Deposition on film-cooled turbine components was studied in an accelerated test facility. The accelerated deposition facility seeds a natural-gas burning combustor with finely ground coal ash particulate at 1180 C and 180 m/s (M=0.25). Both cylindrical and shaped holes, with and without thermal barrier coating, were studied over a range of blowing ratios from 0.5 to 4.0. Coolant density ratios were maintained at values from 2.1 to 2.4. Deposition patterns generated with the cylindrical film cooling holes indicated regions of low deposition in the path of the coolant with heightened deposition between film holes. This distinctive pattern was more accentuated …

Coal Swelling Model For Pressurized High Particle Heating Rate Pyrolysis Applications, Randy C. Shurtz, Joseph W. Hogge, Kade C. Fowers, Gregory S. Sorensen, Thomas H. Fletcher

Faculty Publications

A model was previously developed to describe the decrease in swelling during coal pyrolysis at atmospheric pressure when maximum particle heating rates increase from 10⁴ K/s to 10⁵ K/s. That model included effects of coal type using chemical structure properties. This paper presents results of new experiments to study the effects of elevated pressure and high heating rates on coal pyrolysis. A pressurized flat-flame burner (PFFB) was designed and built to conduct these studies. The pyrolysis experiments reported in this paper were conducted at particle heating rates of ∼105 K/s and maximum gas temperatures of 1700 to 1900 …

Fluidic Assembly At The Microscale: Progress And Prospects, Nathan B. Crane, Onursal Onen, Jose Carballo, Qi Ni, Rasim Guldiken

Faculty Publications

Assembly permits the integration of different materials and manufacturing processes to increase system functionality. It is an essential step in the fabrication of useful systems across size scales from buildings to molecules. However, at the microscale, traditional “grasp and release” assembly methods and chemically inspired self-assembly processes are less effective due to many scaling effects. Many methods have been developed for improving microscale assembly. Often these methods include fluidic forces or the use a fluidic medium in order to enhance their performance. This paper reviews basic assembly theory and modeling methods. Three basic assembly strategies (tool-directed, process-directed, and part-directed) are …

Calling For Justice In The Goldfields Of Tanzania, Madoshi H. Makene, Jody Emel, James T. Murphy

Geography

Tanzania is the third largest gold exporter in Africa, thanks in part to the liberalization of the mining sector which started in the early 1990s. Neoliberal mining reforms promised a win-win situation in which government, investors and local host communities would benefit through export earnings, profits, local employment, andcorporate social responsibility initiatives (e.g., the building of schools and clinics). While the rising price of gold and foreign investments in mining activities have delivered on some of these promises, many residents in mining regions have not benefited socioeconomically. Worse still, their communities have unjustly borne the brunt of the environmental, social, …

Incorporating The Delphi Technique To Investigate Renewable Energy Technology Transfer In Saudi Arabia, Nasir K. Al-Otaibi

Dissertations and Theses @ UNI

Saudi Arabia is a major oil-producing nation facing a rapidly-growing population, high unemployment, climate change, and the depletion of its natural resources, potentially including its oil supply. Technology transfer is regarded as a means to diversify countries' economies beyond their natural resources. This dissertation examined the opportunities and barriers to utilizing technology transfer successfully to build renewable energy resources in Saudi Arabia to diversify the economy beyond oil production. Examples of other developing countries that have successfully used technology transfer to transform their economies are explored, including Japan, Malayasia, and the United Arab Emirates. Brazil is presented as a detailed …

Ergonomics Evaluation Of Task Demands Among Kitchen Staff, Jaqueline Pereira Da Silva

Dissertations and Theses @ UNI

The purpose of this study was to evaluate the workplace demands faced by a group of kitchen staff at six dining centers and to survey musculoskeletal complaints among this sample of workers. The dining centers were located in six different public elementary and middle schools in a city in the south of Brazil. This research was developed following qualitative research design, and the researcher made use of the “Activity Oriented Ergonomics (AOE) methodology.

The AOE focuses on the work analysis that evaluates real work situations that allows a reassessment of work demands. In this case the chosen methodology was a …

Limited Assessment Of A Selected Particulate Matter Sensor Technology In Emission Measurement Applications On Diesel Vehicles, Svetlana Korotkova Espinosa

Dissertations and Theses @ UNI

The study assessed the ability of a novel particle sensor to provide adequate evaluation of real-time emissions from modem diesel engines and estimate the effectiveness of emission control devices. Emission data were obtained from vehicles in real-world field conditions under various test cycles. The datasets were used to determine whether there is an association between particulate matter (PM) measurements produced by particle sensor and the PM measurements from reference instrument. Exploratory analysis was combined with statistical techniques to investigate suitability of particle sensor to adequately measure PM mass concentrations in exhaust gases of modem diesel vehicles. Results of the study …

Coolant Fluid In A Turning Operation: Soybean Coolant Fluid In Different Concentrations Versus Petroleum Coolant Fluid, Mary Esther Eckman

Dissertations and Theses @ UNI

The manufacturing sector today's market felt the need to reduce costs along with the ability to be more "green."

Traditionally petroleum based fluids are used in the manufacturing industry. However they are environmentally more harmful as well as cause significant hazards to the operator. This thesis will provide a case study for this sector to become more environmentally friendly with the use of a soybean based cutting fluid. To prove the point a number of tests were performed turning 4140 steel on a CNC turning center. A number of tests were conducted to provide a comparative study of dry, petroleum …

The Integration Of Wind Energy In The Electrical Grid During The Contingencies, Islam Ali

Dissertations and Theses @ UNI

As wind energy expansion develops, there are also many problems and challenges to connect the wind farms to the grid. There are many different interactions during the connection like the voltage flicker, harmonics, transient, short circuit current, frequency, and safety protection. Those problems may affect the performance of the grid and may cause serious problems. This study investigates the grid-connection problems for the wind turbines and offers appropriate solutions. This study provides a simulation for the power system during the faults. The electrical grid in the simulation contains generators and wind turbines which are connected to the grid. It also …

Robotic Manufacturing Cell: An Analysis Of Variables Affecting Performance, Elvis Alicic

Dissertations and Theses @ UNI

Analyzing the performance of manufacturing cells is a well established concept. The justification for conducting thorough analyses of manufacturing cells comes from the known advantages it can provide, including performance improvement and production planning improvement, both current and future. This study focuses on assessing the variables affecting performance of a robotic manufacturing cell through the measure of throughput. Initially, simulation modeling is utilized to model an existing robotic cell and compare the output to actual production output from the same cell. Additionally, general regression modeling is employed to analyze the following variables and their effect on throughput: machine downtime, off-plan …

An Investigation On In-Process Spc Sampling Frequency For Shaft Bearing Turning Process, Jiaxu Chu

Dissertations and Theses @ UNI

The machining processes have the uniqueness of discrete production and flexible scheduling as cellular manufacturing design. To ensure the quality of machining products, control charts for Statistical Process Control (SPC) has been implemented in the company to monitor the machining process. Sampling is an essential part of data collection for SPC control charts and sampling should be done for machining processes becomes an issue in the company.

This study focused on the investigation of SPC sampling frequencies for shaft bearing turning process using the technique of Average Production Length (APL). The purpose of the study was to identify the SPC …

Modeling And Analysis Of Grid-Connected Solar-Wind Hybrid Power System, Sultan Altamimi

Dissertations and Theses @ UNI

Renewable energies are considered to be a significant part of the energy mix to assist the existing electricity demand and the future of electrical generation. Electrical power simulation software is increasingly being used to answer and determine the source of potential problems in the actual power system. To have a better understanding of an electrical power system, it is essential to validate all the components through simulation within an environment that allows accurate modeling of all power system components. This research presents modeling and analysis of an actual grid-connected solar-wind hybrid system at University of Northern Iowa campus in Cedar …

Computationally Efficient Finite Element Models Of The Lumbar Spine For The Evaluation Of Spine Mechanics And Device Performance, Sean D. Smith

Electronic Theses and Dissertations

Finite Element models of the lumbar spine are commonly used for the study of spine mechanics and device performance, but have limited usefulness in some applications such as clinical and design phase assessments due to long analysis times. In this study a computationally efficient L4-L5 FSU model and a L1-Sacrum multi-segment model were developed and validated. The FSU is a functional spine unit consisting of two adjacent vertebral bodies, in this case L4 and L5. The multi-segment model consists of all lumbar vertebrae and the sacrum. The models are able to accurately predict spine kinematics with significantly reduced analysis times, …

Explicit Finite Element Modeling Of The Human Lumbar Spine, Milind Rao

Electronic Theses and Dissertations

Validated finite element (FE) models of the functional spinal unit (FSU) and lumbar spine are essential in design-phase device development and in assessing the mechanics associated with normal spine function and degenerative disc disease (DDD), as well as the impact of fusion and total disc replacement (TDR). Although experimental data from fully intact specimens can be used for model calibration and validation, the contributions from the individual structures (disc, facets, and ligaments) may be inappropriately distributed. Hence, creation of decompression conditions or device implantations that require structure removal may not have the proper resulting mechanics. An explicit FE formulation may …

Ballistic Imaging Of Sprays At Diesel Relevant Conditions, Jason M. Porter, S. P. Duran, T. E. Parker

Faculty Publications

Diesel engines are an important aspect of our transportation infrastructure, whose performance is greatly affected by the characteristics of the spray from their injectors. Characterization of the injector’s spray is therefore tantamount to clean-running efficient diesel motors. In this study, a ~15 ps pulsed Leopard D-10 laser is used along with an optical Kerr Cell to realize ballistic images of high-delivery-pressure dodecane sprays injected into a quiescent air environment at elevated temperature and pressure. Using CS2 as the Kerr switching media and by optimizing the overlap of the gate and imaging beams, an effective high speed shuttering effect is obtained. …

Low-Voltage Closed Loop Mems Actuators, Shahrzad Towfighian, Glenn Heppler, Eihab Abdel-Rahman

Mechanical Engineering Faculty Scholarship

An efficient electrostatic resonator is designed by adding a low voltage controller to an electrostatic actuator. The closedloop actuator shows stable, and bi-sable behaviors with bounded chaotic oscillations as large as 117% of the capacitor gap. The controller voltage is decreased from a previously designed resonator to less than 9 V thereby reducing the load on the controller circuit components. Bifurcation diagrams are obtained showing the frequency and magnitude of AC voltage required for chaotic oscillations to develop. The information entropy, a measure of chaotic characteristic, is calculated for the micro-resonator and is found to be 0.732.

A Sociable Humanoid Autonomous Robotic Platform (The Sharp Project): An Evaluation Of The G.E.N.E.S.I.S. Robot As An Interactive Consumer Robotic Platform, Jeffrey J. Rick

Dissertations and Theses @ UNI

The Social Humanoid Autonomous Robotic Platform (SHARP) project is an android project that was created with the intent of making learning about androids and robotics easier for the novice, diverse for the expert, educational in the classroom, and useful in the home or business. The project centers itself on its simplicity, low cost, and expandability. This paper illustrates how the SHARP Project has the potential to be an affordable fit in nearly every modern setting. The introduction of the SHARP project lays the groundwork for people of many ages, incomes, and educational levels to take advantage of robotics technology. The …

Development Of A Modular Dual Engine Hybrid Electric Vehicle Simulation Model, Kenan Baltaci

Dissertations and Theses @ UNI

Depleting resources of fossil fuel, climate change impacts, high oil prices, and strict emission requirements are leading to the research on efficient, environmentally friendly, and lowered fossil fuel dependent solutions in the transportation field. While a number of studies used computer modeling and simulation tools to investigate hybrid electric vehicles (HEVs), very few attempted to model and simulate a dual-engine hybrid vehicle. Designing a vehicle engine to meet energy needs in the fully loaded condition is not an optimal solution for manufacturers and customers. The larger the engine, the higher the manufacturing costs for companies, and higher fuel consumption for …