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Full-Text Articles in Engineering

Nanomechanical Characterization Of Fuel Cell Ionomers, Jackson Goddard Apr 2020

Nanomechanical Characterization Of Fuel Cell Ionomers, Jackson Goddard

UCARE Research Products

Energy sustainability can be achieved by improving and adopting clean energy technologies, and a better nanoscale understanding of ionomer-catalyst layers could lead to increased efficiency of proton exchange membrane fuel cells. Samples of Nafion ( Perfluorosulfonic acid ionomer) and PFIA (Perfluoroimide acid ionomer) of varying film thickness were prepared and then studied using contact resonance force microscopy. It was determined that storage and loss modulus increase as relative humidity increases and ionomer film thickness goes below 100 nm. Furthermore, in this specific study, the similar storage and loss modulus of Nafion and PFIA could be attributed to similar backbone structure and ...


Electrification Of Domestic Hot Water To Aid The Integration Of Renewable Energy In The California Grid, Alejandro Cervantes Jan 2020

Electrification Of Domestic Hot Water To Aid The Integration Of Renewable Energy In The California Grid, Alejandro Cervantes

HSU theses and projects

Water heating in residential buildings, also known as domestic hot water (DHW), is the third largest use of energy after appliances and space conditioning. About 90% of the residential buildings in the state use natural gas fueled water heaters, 6% use electricity, and a small percent use liquefied petroleum gas (LPG) or solar water heaters. The current energy use associated with residential water heating is small relative to the total amount of energy consumption in the residential building sector, but it is still a contributor of greenhouse gas (GHG) emissions. Improving hot water systems can be beneficial for bill customer ...


Experimental Investigation Of Low-Voltage Silicon Carbide (Sic) Semiconductor Devices For Power Conversion Applications, Saleh Salem H. Alharbi Jan 2020

Experimental Investigation Of Low-Voltage Silicon Carbide (Sic) Semiconductor Devices For Power Conversion Applications, Saleh Salem H. Alharbi

Electronic Theses and Dissertations

Enhancing the performance and efficiency of power converter systems requires fast-switching power devices with considerably low switching and conduction losses. Silicon (Si) semiconductor devices are the essential components in electronic converter designs, and their behaviors and switching characteristics determine the system’s overall performance and efficiency. These conventional Si devices are nearing to hit their physical and operational limits in meeting power converter requirements with respect to high temperature and large voltage conditions. However, silicon carbide (SiC) power devices enable greater converter efficiency and better power density, particularly under hard switching frequencies and high output voltages due to their outstanding ...


Experimental Evaluation Of Medium-Voltage Cascode Gallium Nitride (Gan) Devices For Bidirectional Dc–Dc Converters, Salah Salem H. Alharbi Jan 2020

Experimental Evaluation Of Medium-Voltage Cascode Gallium Nitride (Gan) Devices For Bidirectional Dc–Dc Converters, Salah Salem H. Alharbi

Electronic Theses and Dissertations

As renewable energy sources, such as photovoltaic (PV) cells and wind turbines, are rapidly implemented in DC microgrids, energy storage systems play an increasingly significant role in ensuring uninterrupted power supply and in supporting the reliability and stability of microgrid operations. Power electronics, especially bidirectional DC–DC converters, are essential parts in distributed energy storage and alternative energy systems because of their grid synchronization, DC power management, and bidirectional power flow capabilities. While there is increasing demand for more efficient, compact, and reliable power converters in numerous applications, most existing power converters are hindered by traditional silicon (Si) based semiconductors ...


Gasification Of Pelletized Corn Residues With Oxygen Enriched Air And Steam, Poramate Sittisun, Nakorn Tippayawong, Sirivatch Shimpalee Oct 2019

Gasification Of Pelletized Corn Residues With Oxygen Enriched Air And Steam, Poramate Sittisun, Nakorn Tippayawong, Sirivatch Shimpalee

Faculty Publications

This work studied generation of producer gas using oxygen-enriched air and steam mixture as gasifying medium. Corn residues consisting of cobs and stover were used as biomass feedstock. Both corn residues were pelletized and gasified separately with normal air, oxygen enriched air and steam mixture in a fixed bed reactor. Effects of oxygen concentration in enriched air (21-50%), equivalence ratio (0.15-0.35), and steam to biomass ratio (0-0.8) on the yield of product gas, the combustible gas composition such as H2, CO, and CH4, the lower heating value (LHV), and the gasification efficiency were investigated. It was found ...


Notes On The Economics Of Residential Hybrid Energy System, Mahelet G. Fikru, Gregory M. Gelles, Ana M. Ichim, Joseph D. Smith Jul 2019

Notes On The Economics Of Residential Hybrid Energy System, Mahelet G. Fikru, Gregory M. Gelles, Ana M. Ichim, Joseph D. Smith

Economics Faculty Research & Creative Works

Despite advances in small-scale hybrid renewable energy technologies, there are limited economic frameworks that model the different decisions made by a residential hybrid system owner. We present a comprehensive review of studies that examine the techno-economic feasibility of small-scale hybrid energy systems, and we find that the most common approach is to compare the annualized life-time costs to the expected energy output and choose the system with the lowest cost per output. While practical, this type of benefit—cost analysis misses out on other production and consumption decisions that are simultaneously made when adopting a hybrid energy system. In this ...


Sorption-Based Energy Storage Systems: A Review, Kyaw Thu, Nasruddin Nasruddin, Sourav Mitra, Bidyut Baran Saha Apr 2019

Sorption-Based Energy Storage Systems: A Review, Kyaw Thu, Nasruddin Nasruddin, Sourav Mitra, Bidyut Baran Saha

Makara Journal of Technology

Mismatched timing between the supply and demand of energy calls for reliable storage systems. Energy storage systems have become further significant with the widespread implementation of renewable energy. These systems can mitigate problems that are often associated with renewable energy sources such as supply unreliability while meeting the de-mand during peak hours. Energy can be stored in various forms, yet storage systems can be generally grouped based on their output forms, namely (i) electricity and (ii) heat or thermal energy. Electrical energy is the most convenient and effective form since it can power almost all modern devices. However, the electricity ...


Supported Perovskite-Type Oxides: Establishing A Foundation For Co2 Conversion Through Reverse Water-Gas Shift Chemical Looping, Bryan J. Hare Mar 2018

Supported Perovskite-Type Oxides: Establishing A Foundation For Co2 Conversion Through Reverse Water-Gas Shift Chemical Looping, Bryan J. Hare

Graduate Theses and Dissertations

Perovskite-type oxides show irrefutable potential for feasible thermochemical solar-driven CO2 conversion. These materials exhibit the exact characteristics required by the low temperature reverse water-gas shift chemical looping process. These properties include structural endurance and high oxygen redox capacity, which results in the formation of numerous oxygen vacancies, or active sites for CO2 conversion. A major drawback is the decrease in oxygen self-diffusion with increasing perovskite particle size. In this study, the La0.75Sr0.25FeO3 (LSF) perovskite oxide was combined with various supports including popular redox materials CeO2 and ZrO2 along with ...


Vanadium Redox Flow Batteries: Design And Experimentation, Matthew George Jan 2018

Vanadium Redox Flow Batteries: Design And Experimentation, Matthew George

Williams Honors College, Honors Research Projects

Vanadium flow batteries (VFB) are a type of battery that has potential as a grid-scale energy storage solution. An original design for a lab-scale VFB is presented herein, along with a procedure for electrolyte preparation from V2O5 using oxalic acid. The flow cell is constructed from Delrin, Teflon, Kynar, Santoprene, Nafion, graphite plate, and porous carbon. Two diaphragm pumps along with polyethylene, PVC, and Santoprene tubing are used. The active area is 58 cm2. The battery was charged using a DC power supply at a constant current of 4 A with corresponding initial voltage of 5 ...


Characterization Of Catalysts For Hydrodeoxygenation Of Bio-Oils Using Phenol As A Model Compound, Abdulazeez Mohammed Khlewee Aug 2017

Characterization Of Catalysts For Hydrodeoxygenation Of Bio-Oils Using Phenol As A Model Compound, Abdulazeez Mohammed Khlewee

Electronic Theses and Dissertations

Due to the environmental considerations, depletion of fossil fuel reserves and fluctuating non-renewable fuel price, converting non-edible lignocellulosic biomass into renewable energy resources has gained significant importance. Phenol has been chosen as a model compound for catalytic screening because it is abundant in bio-oil composition and shows a high resistance to oxygen removal during hydrodeoxygenation (HDO) reactions. HDO of phenol produces chemicals that can be used as transportation fuels (Aromatics) or fuel additives. Theoretically, HDO of phenol has two distinct reduction pathways: direct deoxygenation (DDO) and hydrogenation (HYD). The previous results published by our group showed a precedent activity and ...


Novel Iii-V Alloys For Unassisted Water Splitting., Alejandro Martinez-Garcia May 2017

Novel Iii-V Alloys For Unassisted Water Splitting., Alejandro Martinez-Garcia

Electronic Theses and Dissertations

Direct conversion of solar energy to fuels by photoelectrochemical (PEC) water splitting has been identified as a promising route for sustainable power generation and storage. However, semiconductor materials with suitable opto-electronic properties have yet to be identified. In this dissertation, band gap engineering of III-V alloys, tuning the light sensitivity of GaP and GaN nitride through alloying Sb, is investigated for developing new semiconductor alloys with appropriate opto-electronic properties and their performance with overall water photoelectrolysis. In addition to III-V materials, copper oxide (Cu2O) electrode was investigated for p-type semiconductor material. The new III-V alloy anodes were studied ...


Optimization Of Electricity Generation Schemes In The Java-Bali Grid System With Co2 Reduction Consideration, Farizal Farizal, Wenty Eka Septia, Amar Rachman, Nasruddin Nasruddin, Teuku Meurah Indra Mahlia Aug 2016

Optimization Of Electricity Generation Schemes In The Java-Bali Grid System With Co2 Reduction Consideration, Farizal Farizal, Wenty Eka Septia, Amar Rachman, Nasruddin Nasruddin, Teuku Meurah Indra Mahlia

Makara Journal of Technology

This research considers the problem of reducing CO2 emissions from the Java-Bali power grid system that consists of a variety of power-generating plants: coal-fired, natural gas, oil, and renewable energy (PV, geothermal, hydroelectric, wind, and landfill gas). The problem is formulated as linear programming and solved using LINGO 10. The model was developed for a nation to meet a specified CO2 emission target. Two carbon dioxide mitigation options are considered in this study, i.e. fuel balancing and fuel switching. In order to reduce the CO2 emissions by 26% in 2021, State Electric Supply Company (PLN) has to generate up ...


Sym Executive Summary, João Gomes Dec 2015

Sym Executive Summary, João Gomes

João F Gomes

Project SYM Executive Summary


Methanation Note.Pdf, João Gomes Dec 2015

Methanation Note.Pdf, João Gomes

João F Gomes

Technical note on methanation (results of SYM project)


Process Design, Dynamics, And Techno-Economic Analysis Of A Sustainable Coal, Wind, And Small Modular Nuclear Reactor Hybrid Energy System, Kyle Lee Buchheit Jan 2015

Process Design, Dynamics, And Techno-Economic Analysis Of A Sustainable Coal, Wind, And Small Modular Nuclear Reactor Hybrid Energy System, Kyle Lee Buchheit

Doctoral Dissertations

"The availability of cheap electricity is one of the biggest factors for improving quality of life. With the debate on the effects of carbon dioxide emissions continuing, several countries have either implemented or are considering the reduction of emissions through various economic means. The inclusion of a monetary penalty on carbon emissions would increase the prices of electricity produced by carbon-based sources. The push for large-scale renewable sources of energy has met problems with regards to energy storage and availability. The proposed coal, wind, and nuclear hybrid energy system would combine a renewable energy source, wind, with traditional and stable ...


A Comprehensive Optimization Framework For Designing Sustainable Renewable Energy Production Systems, Aryan Geraili Nejadfomeshi Jan 2015

A Comprehensive Optimization Framework For Designing Sustainable Renewable Energy Production Systems, Aryan Geraili Nejadfomeshi

LSU Doctoral Dissertations

As the world has recognized the importance of diversifying its energy resource portfolio away from fossil resources and more towards renewable resources such as biomass, there arises a need for developing strategies which can design renewable sustainable value chains that can be scaled up efficiently and provide tangible net environmental benefits from energy utilization. The objective of this research is to develop and implement a novel decision-making framework for the optimal design of renewable energy systems. The proposed optimization framework is based on a distributed, systematic approach which is composed of different layers including systems-based strategic optimization, detailed mechanistic modeling ...


Production Of Renewable Chemicals And Energy From Waste Biomass, Sheng Chu Nov 2014

Production Of Renewable Chemicals And Energy From Waste Biomass, Sheng Chu

Doctoral Dissertations

With the rapid growth of world population and developing industries, the production of wastes has dramatically increased in the past decades. Due to environmental concerns and limited landfill space, the disposal of wastes has been subjected to strict regulations. Beneficial uses of wastes such as recycling/reuse, land applications, energy production, and resource recovery have been advocated greatly. This thesis presents the utilization of two types of solid waste: lignin and waste paper/plastic. Through thermochemical conversion, wastes can be converted to chemicals and energy. This aims at reducing the energy dependence on fossil fuels while achieving effective waste management ...


The Role Of Surface Area In Catalytic Gasification Of Biomass, Elizabeth A. Wachs, Nitish Kumar, Indraneel Sircar, Prithviraja Basak, Jay P. Gore Phd Aug 2014

The Role Of Surface Area In Catalytic Gasification Of Biomass, Elizabeth A. Wachs, Nitish Kumar, Indraneel Sircar, Prithviraja Basak, Jay P. Gore Phd

The Summer Undergraduate Research Fellowship (SURF) Symposium

Gasification of biomass has the potential to provide a carbon-negative source of liquid fuels. The current limited use of gasification is due in part to the high temperatures necessary to achieve high conversion levels. These temperatures can be lowered by the use of catalysts, but the mechanisms by which catalysts affect the reaction rate are not fully understood. Here, the structural component of potassium carbonate’s role in the gasification process was examined. Samples of pinewood sawdust were impregnated with potassium carbonate, then pyrolyzed with N2 in a fixed bed reactor at 750°C (heater thermocouple reading). Half of the ...


Electrocatalytic Processing Of Renewable Biomass-Derived Compounds For Production Of Chemicals, Fuels And Electricity, Le Xin Jan 2014

Electrocatalytic Processing Of Renewable Biomass-Derived Compounds For Production Of Chemicals, Fuels And Electricity, Le Xin

Dissertations, Master's Theses and Master's Reports - Open

The dual problems of sustaining the fast growth of human society and preserving the environment for future generations urge us to shift our focus from exploiting fossil oils to researching and developing more affordable, reliable and clean energy sources. Human beings had a long history that depended on meeting our energy demands with plant biomass, and the modern biorefinery technologies realize the effective conversion of biomass to production of transportation fuels, bulk and fine chemicals so to alleviate our reliance on fossil fuel resources of declining supply. With the aim of replacing as much non-renewable carbon from fossil oils with ...


Cdm Potential In Palm Solid Waste Cogeneration As An Alternative Energy In Aceh Province, Mahidin Mahidin, Izarul Machdar, Muhammad Faisal, Muhammad Nizar Nov 2012

Cdm Potential In Palm Solid Waste Cogeneration As An Alternative Energy In Aceh Province, Mahidin Mahidin, Izarul Machdar, Muhammad Faisal, Muhammad Nizar

Makara Journal of Technology

Empty Fruit Bunch (EFB) as a solid waste in Crude Palm Oil (CPO) industry does not utilized yet as an alternative energy source to generate electricity. It is well known that use of solid wate (biomass) as an energy source is part of the Clean Development Mechanism (CDM) scheme due to direct reduction of Green House Gases (GHGs) emission and provide a direct contribution to sustainable development. Utilization of EFB as a source of energy is very potential to be implemented in Aceh since this province has 25 CPO Mills at the moment which actively produce about 870,000 ton ...


Status Of Biodiesel Research And Development In Pakistan, Abdul Aziz Abdul Raman Aug 2012

Status Of Biodiesel Research And Development In Pakistan, Abdul Aziz Abdul Raman

Abdul Aziz Abdul Raman

Performance of biodiesel in engines is well established and biodiesel is currently adjudged as a low carbon fuel with the most potential of replacing fossil fuels. The fossil fuel sources are dwindling in Pakistan resulting in importation of about 8.1 million tonnes at approximately US$ 9.4 billion per annum. In the ambit of this justification, augmenting the energy scarce resources in Pakistan through intense harnessing of the varied biodiesel sources can adequately address the deficiency and can ensure energy security. Towards this end, the progress attained in biodiesel related researches in Pakistan are evaluated and presented with the ...


Bubble-Free Oxygen And Carbon Dioxide Mass Transfer In Bioreactors Using Microporous Membranes, Ravi Balgobin Apr 2012

Bubble-Free Oxygen And Carbon Dioxide Mass Transfer In Bioreactors Using Microporous Membranes, Ravi Balgobin

Electronic Thesis and Dissertation Repository

Increasing gas-liquid mass transfer in bioreactors is a major goal for performance improvement in bioprocesses. The effects of bubble-free oxygen and carbon dioxide mass transfer using microporous membranes were tested in a flat module and a hollow fiber module for applications in a bio-fuel cell and cultivation of microalgae. The volumetric mass transfer coefficient, KLa, was compared to conventional bubbling. Liquid agitation rates influenced the mass transfer, as the limiting factor was the liquid boundary layer thickness. The KLa increased as the membrane hydrophobicity increased. The effect of pore size was found to be negligible for ...


Reflexions On The Use Of Renewable Power Sources And Nuclear Energy In Portugal, João F. Gomes Jan 2008

Reflexions On The Use Of Renewable Power Sources And Nuclear Energy In Portugal, João F. Gomes

João F Gomes

This paper analyses the current energy balance of Portugal, considering the actual sources which are mainly traditional fossil fuels, hydroelectric power and renewables. Other potential sources are discussed also and taken into consideration in view of the previewed evolution of the country in energetic terms. Among these, nuclear power, once regarded as an option, is now being re-considered. This paper also sums up the main issues to be considered in a future debate on the subject.