Digital Commons Network^™

Electrochemical Detection Of Low-Concentration Lead (Ii) Ions From Water, Mohmmad Rizwen Ur Rahman

Theses and Dissertations

The aim of this study was to develop an electrochemical sensor for speedy, selective and sensitive detection of lead ion (Pb2+) using graphene oxide and pyrrole nanocomposite. Different combinations of graphene oxide and pyrrole in layers and mixtures were tested for the finest sensitive detection of lead ion (Pb2+). Reduced graphene oxide and polypyrrole (rGO-PPY as layer) nanocomposite modified screen printed electrode (SPE) showed the best signal in response to the differential pulse anodic stripping voltammetry (DPASV) with a limit of detection to 5 ppb. The rGO-PPY modified electrode possessed a large effective surface area because of the unique 3D …

Pulsed Flow Jet Impingement Cooling: Evaluation Of Heat Transfer Performance, Michael Lee Hamman

Theses and Dissertations

This thesis presents findings from an experimental and numerical investigation into merits of pulse coolant flow as an improvement to impingement cooling. A series of simulations were conducted at Re=12k and 30k for frequencies up to 20Hz and amplitude ratios up to 70% of mean mass flow and standoff and nozzle spacing equal to three diameters. Square waveforms were found to degrade at low frequencies near 1Hz, rendering the use of square waveforms as an invalid mass flow specifications for inlet boundaries in computational predictions. The Power Consumption Ratio is introduced for comparing pulse and steady flow configuration’s energy consumption. …

Design For Safety: Characterization Of Structural Impact On Lithium-Ion Batteries, Mehdi Gilaki

Theses and Dissertations

The goal of this research is to develop a framework for design for safety of battery modules used in EV/HEV applications. Such a framework can enhance the crash safety of lithium-ion batteries by investigating prevailing failure mechanisms such as thermal runaway. The problem involves different scales from module level to laminate level. The multi-scale nature of the problem makes the analysis computationally complex and expensive. Furthermore, because of the risk of explosion, a battery testing apparatus needs special safety provisions making it difficult to test charged and ready-to-use battery cells. In this study, we have numerically investigated feasibility of using …

A Study Of Development Of A Micro Hydro Turbine System With A Rim Drive And Air Injection Treatment For Cavitation., Tomoki Sakamoto

Theses and Dissertations

This thesis presents the study of Kaplan hydro turbines system at a very low head and air injection treatment to reduce cavitation happening around a turbine. Regarding the study of Kaplan hydroturbine system, optimization of hydro turbine system with a rim generator to gain a better performance was conducted by CFD and experiment. E-Motors, the partner of this research, is developing an integrated design to simplify manufacturing and installation. The integrated design includes a rim in the outside of the turbine runner to house the electrical generator rotor, namely rim drive. This approach enables a compact and simple assembly without …

An Array Of Circular Dielectrophoresis Traps To Separate And Charaterize Individual Microparticles From Population, Hwangjae Lee

Theses and Dissertations

Dielectrophoretic traps have been broadly studied in light of their many advantages of high controllability, ease of operation, and high efficiency. In the previous studies, however, it was challenging to count captured particles or required work to capture particles. In the thesis, an array of circular dielectrophoresis (DEP) traps was developed and tested to manipulate population of microparticles in single particle level. The circular DEP traps enable more precise control of the force field than conventionally used interdigitated electrodes due to its omnidirectional and symmetric properties. The location of the captured microparticle inside the trap was confirmed by both of …

Design And Development Of A Robot Guided Rehabilitation Scheme For Upper Extremity Rehabilitation, Md Assad-Uz-Zaman

Theses and Dissertations

To rehabilitate individuals with impaired upper-limb function, we have designed and developed a robot guided rehabilitation scheme. A humanoid robot, NAO was used for this purpose. NAO has 25 degrees of freedom. With its sensors and actuators, it can walk forward and backward, can sit down and stand up, can wave his hand, can speak to the audience, can feel the touch sensation, and can recognize the person he is meeting. All these qualities have made NAO a perfect coach to guide the subjects to perform rehabilitation exercises. To demonstrate rehabilitation exercises with NAO, a library of recommended rehabilitation exercises …

Numerical Study Of Thermal Performance Improvement By Novel Structures In The Building Energy Storage Systems, Junling Xie

Theses and Dissertations

In this work, numerical studies were conducted to investigate the effectiveness of two fin-like novel structures used for heat-transfer enhancement in two building energy storage systems including thermal energy storage and battery energy storage.

Firstly, thin layer ring structure was numerically investigated for thermal performance improvement in the thermal energy storage. From the results obtained in this study, the area ratio can be increased by 4% when using the thin layer ring during the same time period. The thin layer ring structure can shorten ice formation period and increase its efficiency. Further study was conducted for the factorial analysis of …

Investigation Of A Novel Turbulence Model And Using Leading-Edge Slots For Improving The Aerodynamic Performance Of Airfoils And Wind Turbines, Saman Beyhaghi

Theses and Dissertations

Because of the problems associated with increase of greenhouse gases, as well as the limited supplies of fossil fuels, the transition to alternate, clean, renewable sources of energy is inevitable. Renewable sources of energy can be used to decrease our need for fossil fuels, thus reducing impact to humans, other species and their habitats. The wind is one of the cleanest forms of energy, and it can be an excellent candidate for producing electrical energy in a more sustainable manner. Vertical- and Horizontal-Axis Wind Turbines (VAWT and HAWT) are two common devices used for harvesting electrical energy from the wind. …

Performance Optimization Of Onboard Lithium Ion Batteries For Electric Vehicles, Rohit Anil Ugle

Theses and Dissertations

Next generation of transportation in the form of electric vehicles relies on better operation and control of large battery packs. The individual modules in large battery packs generally do not have identical characteristics and may degrade differently due to manufacturing variability and other factors. Degraded battery modules waste more power, affecting the performance and economy for the whole battery pack. Also, such impact varies with different trip patterns. It will be cost effective if we evaluate the performance of the battery modules prior to replacing the complete battery pack. The knowledge of the driving cycle and battery internal resistance will …

Novel Nanomaterials For Lithium Ion Batteries And Oxygen Reduction Reactions, Jianyang Li

Theses and Dissertations

Undoubtedly, one of the most pressing issues that world is dealing with today is global warming. It requires long-term potential actions for sustainable development to achieve solutions to address this kind of environmental problems that we are facing today. In this regard, renewable energy resources appear to be the one of the most efficient and effective solutions to reduce reliance on fossil fuels that cause release of excess amounts of carbon dioxide, the main contributor to global warming. As an alternative, electrochemical energy production has long been explored due to its intrinsic nature of more sustainable and more environmentally friendly. …