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Full-Text Articles in Engineering

Ac Conductivity Studies Of Polyethylene-Oxide-Garnet Type Li7la3zr2o12 Hybrid Composite Solid Polymer Electrolyte For Li-Ion Battery, Parisa Bashiri Jan 2020

Ac Conductivity Studies Of Polyethylene-Oxide-Garnet Type Li7la3zr2o12 Hybrid Composite Solid Polymer Electrolyte For Li-Ion Battery, Parisa Bashiri

Wayne State University Dissertations

Solid electrolytes including ceramics and polymers are considered to be the ultimate substitute for organic liquid electrolytes currently used in commercialized lithium ion batteries to address the safety concerns due to Li dendrite growth and internal short circuiting. However, low ionic conductivity due to high grain boundary resistance in ceramics and semi-crystalline nature of polymers has held back the solid electrolytes from being used in Li-ion batteries. Polyethylene oxide (PEO), complexed with a Li-salt, is a well-studied polymer electrolyte showing ionic conductivity properties at room temperature. However, the coexistence of amorphous and crystalline regions at room temperature (< Tm, the melting temperature) has

-8 -6 …


Fundamental Insights On The Electrolysis Of Co2 Using Solid Oxide Electrolysis Cells, Juliana Silva Alves Carneiro Jan 2019

Fundamental Insights On The Electrolysis Of Co2 Using Solid Oxide Electrolysis Cells, Juliana Silva Alves Carneiro

Wayne State University Dissertations

The work reported in this thesis focused on providing a fundamental understanding, at the molecular level, required to guide the effective design of electrocatalysts towards a superior reaction kinetics on the electrode of solid oxide electrolysis cells SOECs devices (SOECs) during the CO2 electrolysis. High temperature SOECs are electrochemical energy conversion technologies, that have emerged as promising alternatives to mitigate environmental issues associated with combustion-based technologies, such as the rising atmospheric CO2 levels. The conversion of excess CO2 into high-energy molecules, such as CO can be efficiently achieved through the use of SOEC – which facilitates the electrochemical reduction of …


Study Of Periodical Flow Heat Transfer In An Internal Combustion Engine, Xi Luo Jan 2017

Study Of Periodical Flow Heat Transfer In An Internal Combustion Engine, Xi Luo

Wayne State University Dissertations

In-cylinder heat transfer is one of the most critical physical behaviors which has a direct influence on engine out emission and thermal efficiency for IC engine. In-cylinder wall temperature has to be precisely controlled to achieve high efficiency and low emission. However, this cannot be done without knowing gas-to-wall heat flux. This study reports on the development of a technique suitable for engine in-cylinder surface temperature measurement, as the traditional method is “hard to reach.” A laser induced phosphorescence technique was used to study in-cylinder wall temperature effects on engine out unburned hydrocarbons during the engine transitional period (warm up). …


Nano-Structured Electrocatalysts For High Performance Lithium Sulfur Batteries, Negar Mosavati Jan 2016

Nano-Structured Electrocatalysts For High Performance Lithium Sulfur Batteries, Negar Mosavati

Wayne State University Dissertations

Ni nanoparticles has been investigated as a carbon-free cathode material for dissolved polysulfide Li-S battery. A series of Ni nanoparticles with nominal particle size of 20, 40, and 100 nm have been used as electrocatalysts, and the effect of particle size on Li-S battery performance has been investigated. In addition, graphene has been chosen as a support to anchor the Ni nanoparticles, and the synergetic effect of carbon material and Ni nanoparticles on Li-S battery electrochemical performance has been studied. The results indicated there is a strong particle size effect. Ni/graphene electrode exhibits a capacity of 753 mAh g-1 sulfur …


New Approaches To Chalcogenide Materials For Thermoelectrics: Lead Telluride-Based Nanostructures And Facile Synthesis Of Tetrahedrite And Doped Derivatives, Derak Justin James Jan 2016

New Approaches To Chalcogenide Materials For Thermoelectrics: Lead Telluride-Based Nanostructures And Facile Synthesis Of Tetrahedrite And Doped Derivatives, Derak Justin James

Wayne State University Dissertations

The overall purpose of this work is to address several of the roadblocks to use of thermoelectric materials for generation of electricity, namely inefficient processing of materials and low performance, commonly rated by the figure of merit, ZT=T2/tot. The ZT includes  as the Seebeck coefficient,  as electrical resistivity, T as the average temperature, and tot as total thermal conductivity. tot is the sum of electronic charge carrier (C) and lattice (L) contributions to thermal conductivity. Attempts to increase ZT in the literature to values >1 have focused on decreasing the thermal conductivity via nanostructuring or optimizing the electrical …


Novel Design And Synthesis Of Structured Iron Oxides For Battery Applications, Jian Zhu Jan 2016

Novel Design And Synthesis Of Structured Iron Oxides For Battery Applications, Jian Zhu

Wayne State University Dissertations

Lithium-ion batteries (LIBs) are currently the dominant powder source for personal computers and portable electronics. LIBs also play important roles in larger-scale applications, including electric drive vehicles (EVs, HEVs) and grid-energy storage. To meet the increasing demand for energy storage, it is very urgent and crucial to develop next-generation LIBs using alternative electrode materials. For example, carbon is still exclusively used as anode materials in current LIBs. However, the theoretical capacity of graphite (372 mA h g–1 based on LiC6) has almost been achieved, and it becomes one of the bottlenecks to further increase the energy density of LIBs based …


The Energy Trilogy: An Integrated Sustainability Model To Bridge Wastewater Treatment Plant Energy And Emissions Gaps, A. Adhim A. Altalibi Jan 2014

The Energy Trilogy: An Integrated Sustainability Model To Bridge Wastewater Treatment Plant Energy And Emissions Gaps, A. Adhim A. Altalibi

Wayne State University Dissertations

ABSTRACT

An estimated 4% of national energy consumption is used for drinking water and wastewater services. Despite the awareness and optimization initiatives for energy conservation, energy consumption is on the rise owing to population and urbanization expansion and to commercial and industrial business advancement. The principal concern is since energy consumption grows, the higher will be the energy production demand, leading to an increase in CO2 footprints and the contribution to global warming potential.

This research is in the area of energy-water nexus, focusing on wastewater treatment plant (WWTP) energy trilogy - the group of three related entities, which includes …


Development Of Silicon-Based Anodes And In-Situ Characterization Techniques For Lithium Ion Batteries, Jinho Yang Jan 2014

Development Of Silicon-Based Anodes And In-Situ Characterization Techniques For Lithium Ion Batteries, Jinho Yang

Wayne State University Dissertations

Development of lithium ion batteries (LIBs) with higher capacity has been booming worldwide, as growing concerns about environmental issues and increasing petroleum costs. The demands for the LIBs include high energy and power densities, and better cyclic stability in order to meet a wide range of applications, such as portable devices and electric vehicles. Silicon has recently been explored as a promising anode material due to its low discharge potential (<0.4 V) and high specific capacity (4200 mAh g-1). The capacity of silicon potentially exceeds more than 10 times of the conventional graphite anode (372 mAh g-1). However, the silicon anode experiences huge volume …


Study Of Tin-Based Electrodes And Ionic Liquid Electrolytes For Energy Storage Materials, Mahbuba Ara Jan 2014

Study Of Tin-Based Electrodes And Ionic Liquid Electrolytes For Energy Storage Materials, Mahbuba Ara

Wayne State University Dissertations

Due to rapid increase in energy demand, modern society necessitates to develop high power, light-weight, and more economical energy storage systems. Rechargeable Li-ion batteries and Li-oxygen batteries have become the most promising energy devices in terms of energy and power densities. Diverse research on these battery components is being carried out by researchers worldwide to improve power density to meet the future requirements. The possible routes to improving power density of Li-ion as well as Li-oxygen batteries is to use nanostructured, hybrid electrode materials since they can significantly enhance kinetics of electrochemical reactions; and ion-conducting, low volatile electrolytes since they …


Mission Aware Energy Saving Strategies For Army Ground Vehicles, Macam Dattathreya Jan 2013

Mission Aware Energy Saving Strategies For Army Ground Vehicles, Macam Dattathreya

Wayne State University Dissertations

Fuel energy is a basic necessity for this planet and the modern technology to perform many activities on earth. On the other hand, quadrupled automotive vehicle usage by the commercial industry and military has increased fuel consumption. Military readiness of Army ground vehicles is very important for a country to protect its people and resources. Fuel energy is a major requirement for Army ground vehicles. According to a report, a department of defense has spent nearly $13.6 billion on fuel and electricity to conduct ground missions. On the contrary, energy availability on this plant is slowly decreasing. Therefore, saving energy …


Ionization In Diesel Combustion For On-Board Diagnostics And Engine Control, Tamer Hassan Badawy Jan 2013

Ionization In Diesel Combustion For On-Board Diagnostics And Engine Control, Tamer Hassan Badawy

Wayne State University Dissertations

Diesel engines have been known for their high thermal efficiency and specific power output, but there is concern about engine-out NOx and particulate matter emissions. To meet the current emission standards, advanced diesel engines are fitted with electronically controlled fuel injection systems and sophisticated and expensive after-treatment devices. Further improvements are still needed to meet future goals in better fuel economy and the more stringent emission standards. In order to meet these goals, there is a need for the control of the combustion process to reduce engine-out emissions in real-time and reduce the demand on the after-treatment devices. This requires …


Green Diesel Production Via Catalytic Hydrogenation/Decarboxylation Of Triglycerides And Fatty Acids Of Vegetable Oil And Brown Grease, Elvan Sari Jan 2013

Green Diesel Production Via Catalytic Hydrogenation/Decarboxylation Of Triglycerides And Fatty Acids Of Vegetable Oil And Brown Grease, Elvan Sari

Wayne State University Dissertations

Increase in the petroleum prices, projected increases in the world’s energy demand and environmental awareness have shifted the research interest to the alternative fuel technologies. In particular, green diesel, vegetable oil/animal fat/waste oil and grease derived hydrocarbons in diesel boiling range, has become an attractive alternative to biodiesel— a mixture of fatty acid methyl esters, particularly due to its superior fuel properties that are similar to petroleum diesel. Hence, green diesel can be used as a drop-in fuel in the current diesel engines. The current technology for production of green diesel– hydrodeoxygenation of triglycerides and fatty acids over conventional hydrotreating …


Nano-Silicon/Graphene Composite Anodes For Enhanced Performance Lithium Ion Batteries, Rhet Joseph Caballes De Guzman Jan 2013

Nano-Silicon/Graphene Composite Anodes For Enhanced Performance Lithium Ion Batteries, Rhet Joseph Caballes De Guzman

Wayne State University Dissertations

The ever evolving technological applications such as with portable electronics and electric vehicles have led to increasing energy demands that have proven the existing commercial LIB capacity insufficient. Recently, the most promising anode material to substitute the traditional graphite is Si. As an anode Si has low discharge potential and theoretical the highest known theoretical capacity (>10 fold of graphite). However, due to the increased accommodated Li+ during charge-discharge reactions, silicon's volume varies up to 400%, causing pulverization and loss of electrical contact.

This dissertation focuses on a systematic approach in developing effective means to utilize Si for improved …


Multi-Component Ab2 Metal Hydride Alloys For Nickel Metal Hydride Battery Applications, Jean Nei Jan 2012

Multi-Component Ab2 Metal Hydride Alloys For Nickel Metal Hydride Battery Applications, Jean Nei

Wayne State University Dissertations

Compared to the mish metal-based AB5 MH alloy commonly used in Ni/MH batteries, the transition metal-based AB2 MH alloy not only reduces the rare earth dependency, it also has higher specific energy. In order to further improve the performance of AB2 MH alloy, it's crucial to full understand its multi-phase nature, which includes the main C14/C15 Laves phases and the secondary non-Laves phases.

In order to optimize the gaseous phase and electrochemical advantages of both the C14 and C15 Laves phases, a study was established to recognize the factors that affect the C14/C15 phase abundance. Average electron …


Linear And Non-Linear Deformations Of A Wind Turbine Blade Considering Warping And All Aeroelastic Load Couplings, Fouad Mohammad Mohammad Jan 2012

Linear And Non-Linear Deformations Of A Wind Turbine Blade Considering Warping And All Aeroelastic Load Couplings, Fouad Mohammad Mohammad

Wayne State University Dissertations

The structural dynamics behavior of the blade of a horizontal axis wind turbine that reacts to the different components of the aerodynamic loading were studied by many researchers using different approaches and assumptions. In the present research, the author considered all the extensional, torsional and flexural loadings acting on the blade with their couplings, variable airfoil cross sections with warping effects, shear deflection, rotary inertia and with or without blade's pretwist for both the linear small deformation case and the nonlinear large deformation case. To the best knowledge of the author the simultaneous inclusion of all these factors has not …


Biofuels Production From Hydrotreating Of Vegetable Oil Using Supported Noble Metals, And Transition Metal Carbide And Nitride, Huali Wang Jan 2012

Biofuels Production From Hydrotreating Of Vegetable Oil Using Supported Noble Metals, And Transition Metal Carbide And Nitride, Huali Wang

Wayne State University Dissertations

The focus of this research is to prepare non-sulfided hydrotreating catalysts, supported noble metal and transition metal carbide/ nitride, and evaluate their hydrocracking activities and selectivities by using soybean oil as the feedstock. For comparison study, catalytic cracking of soybean oil over a commercialized ZSM-5 was investigated. However, steady state could not be reached because significant amounts of tar and coke were generated during the reaction though a high yield (21%) of jet fuel was obtained from the process. Compared to the catalytic cracking process, less tar and coke were formed during the hydrocracking process and stable continuous flow reaction …