Engineering Commons^™

Photolithography In Fabrication Of Thin-Film Solar Cells, Yusheng Zhu, Rakesh Agrawal

The Summer Undergraduate Research Fellowship (SURF) Symposium

Solar energy has steadily increased its efficiency and cost-effectiveness throughout the past three decades and seems poised to compete with current primary energy (natural gas, oil, coal) as the need for alternative energy sources rises. One type of solar cell, thin-film cells, often relies on use of permanent photomasks in order to imprint a pattern onto the front metal contact. However, these machined metal masks are rigid and do not allow for different designs to be explored as current masks encounter difficulties in machining grids thin enough for optimization. Photolithography, traditionally used in the microfabrication field, provides a method in …

Environmental Monitoring In Preparation For The Installation Of A Green Roof, Andrew N. Martin, Ming Qu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Green roofs are becoming an increasingly popular way to improve the environmental, economic, and aesthetic performance of both new and existing buildings. Along with the green roofs themselves, it is also common to install sensors to measure various environmental parameters that are affected by or important to the operation of the roof such as precipitation, temperature, and runoff. However, for most of these systems, the sensors are installed at the same time or even after the green roof. Therefore, no before-and-after comparisons can be made for those roofs. To account for this missing data, monitoring equipment was installed on a …

Solar Cell Temperature Dependent Efficiency And Very High Temperature Efficiency Limits, John Robert Wilcox

Open Access Dissertations

Clean renewable solar energy is and will continue to be a critically important source of electrical energy. Solar energy has the potential of meeting all of the world's energy needs, and has seen substantial growth in recent years. Solar cells can convert sun light directly into electrical energy, and much progress has been made in making them less expensive and more efficient. Solar cells are often characterized and modeled at 25 °C, which is significantly lower than their peak operating temperature. In some thermal concentrating systems, solar cells operate above 300 °C. Since increasing the temperature drastically affects the terminal …

Characterization Of Biomass Fuel Properties Based On Functional Groups, Richard B. Reid, Dr. Larry Baxter

Journal of Undergraduate Research

The search for sustainable energy sources and technologies is one of the world’s primary concerns in the 21st century. Biomass energy is projected to be an important component of a diverse and sustainable energy portfolio. In order to utilize this source effectively there must be accurate composition data and predictive correlations for material properties. Though the literature provides some empirical correlations of fuel properties such as heating value [Jenkins et al 1996], fundamental chemical and structural analyses have not been explicitly correlated with such properties. This project has sought to establish relationships between fuel properties and chemical functional group contributions …

Development Of A New Energy-Absorbing Roadside/Median Barrier System With Restorable Elastomer Cartridges, Ronald K. Faller, Dean L. Sicking, Karla A. Lechtenberg, Robert W. Bielenberg, Scott K. Rosenbaugh, James C. Holloway, John D. Reid, Jennifer D. Schmidt

Nebraska Department of Transportation: Research Reports

No abstract provided.

Tesla: An Extended Study Of An Energy-Saving Agent That Leverages Schedule Flexibility, Jun Young Kwak, Pradeep Varakantham, Rajiv Maheswaran, Milind Tambe, Burcin Becerik-Gerber

Research Collection School Of Computing and Information Systems

This paper presents transformative energy-saving schedule-leveraging agent (TESLA), an agent for optimizing energy usage in commercial buildings. TESLA’s key insight is that adding flexibility to event/meeting schedules can lead to significant energy savings. This paper provides four key contributions: (i) online scheduling algorithms, which are at the heart of TESLA, to solve a stochastic mixed integer linear program for energy-efficient scheduling of incrementally/dynamically arriving meetings and events; (ii) an algorithm to effectively identify key meetings that lead to significant energy savings by adjusting their flexibility; (iii) an extensive analysis on energy savings achieved by TESLA; and (iv) surveys of real …

Performance Of Solid Oxide Iron-Air Battery Operated At 550°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang

Faculty Publications

“Metal-air” batteries have garnered much attention in recent years due to their high intrinsic specific energy and use of inexhaustible and storage-free oxygen source -air- for the “metal-oxygen” reaction. In this study, we report theperformance of a new type of all solid-state “iron-air” battery operated at 550°C. The results show that CeO₂ nanoparticles incorporated into the Fe-Fe₃O₄ redox-couple can improve the specific energy (Wh/kg) and round trip efficiency by 15% and 29%, respectively, over the baseline Fe-Fe₃O₄ battery. Use of supported Fe-Fe₃O₄ nanoparticles as the redox couple can increase the …

Preliminary Analysis Of Ghg Production From The Lincoln Water System To Determine Operating Energy And Infrastructure Construction Impacts, Martin Gakuria

Department of Environmental Engineering: Theses and Other Student Research

The Lincoln Water System (LWS) provides water to the citizens, industries, and commercial areas within and near the City of Lincoln, Nebraska. The intent of this thesis is to determine if reductions in future per capita water demand will help reduce the building of infrastructure and reduce future pumping costs and uses the computation of greenhouse gasses to compare the effects of different degrees of water conservation.

Data analysis was performed on water production statistics and data (1994-2011) collected and provided by the City of Lincoln, Nebraska. Projections in accordance with the Lincoln-Lancaster County 2040 Comprehensive Plan were made to …

Tesla: An Energy-Saving Agent That Leverages Schedule Flexibility, Jun Young Kwak, Pradeep Varakantham, Rajiv Maheswaran, Burcin Becerik-Gerber, Milind Tambe

Research Collection School Of Computing and Information Systems

This innovative application paper presents TESLA, an agent-based application for optimizing the energy use in commercial buildings. TESLA’s key insight is that adding flexibility to event/meeting schedules can lead to significant energy savings. TESLA provides three key contributions: (i) three online scheduling algorithms that consider flexibility of people’s preferences for energyefficient scheduling of incrementally/dynamically arriving meetings and events; (ii) an algorithm to effectively identify key meetings that lead to significant energy savings by adjusting their flexibility; and (iii) surveys of real users that indicate that TESLA’s assumptions exist in practice. TESLA was evaluated on data of over 110,000 meetings held …

Investigations Of Attitudes Towards Offshore Wind Farm Development In Ireland: Their Implication Towards Future Development Of The Industry., Aidan Melia

Purdue Polytechnic Masters Theses

This current research investigates what the attitudes of Irish people are towards the development of offshore wind farms in Ireland. Using a qualitative approach, a questionnaire is carefully designed and distributed among a sample population from three coastal communities. One is located on the west coast and two on the east coast. The two locations on the east coast have an involvement in offshore wind farms. One of the locations plays host to Ireland’s only offshore wind farm, while there are plans in place for an offshore wind farm at the other location. The results from the questionnaires are analyzed …

Anti-Bacterial Activity Of Indoor Light Activated Photocatalysts, Suresh Pillai, Michael Seery, Damian Synnott, Stephen Hinder, Georg Michlits

Articles

Nanocrystalline photocatalysts, prepared under ambient conditions using a microwave assisted syn-thesis, show indoor light photocatalytic activity for the degradation of Staphylococcus aureus and Escherichia coli. The zinc sulphide (ZnS) nanomaterials, prepared by a microwave assisted synthesis, are shown to be cubic blende structure with an average crystallite size of 4–6 nm. The anti-bacterial activ-ity of these nanomaterials is investigated under irradiation from a 60 W light bulb and photocatalytic activity is revealed to be due to the defects present in the crystal structure. The ZnS shows anti-bacterial action as both a bacteriostatic and bacteriocidal (88% reduction in the amount of …

Aerodynamics Of Biplane Wind Turbine Blades, Phillip K. Chiu

Link Foundation Energy Fellowship Reports

Little is known about the aerodynamics of biplane wind turbine blades. Even more fundamentally, the two-dimensional aerodynamics of thick biplane airfoils are not well-understood. Supported by the Link Foundation Energy Fellowship, this research has sought to develop a better understanding of these aerodynamics through wind tunnel experiments and computational fluid dynamics. An understanding of biplane aerodynamics is a key step towards the commercial implementation of biplane wind turbine blades. These designs could enable larger turbines designs, ultimately reducing the cost of wind-generated electricity and helping to displace conventional means of electricity generation.

Design And Use Of An Adjustable Clearance Flailing Knife Biomass Shredder To Mechanically Increase Particle Surface Area, Shawn Gregory Ehlers

Open Access Theses

A flailing knife shredder was designed and tested as an alternative to a hammermill for processing biomass. The machine was comprised of two cylinders with four rungs, each with five free-swinging blades. Each of the two cylinders had adjustable clearance hoods and variable speed drives. Energy usage, output characteristics and device capacities were compared with corn stover processed at moisture contents (MC) of 10%, 35% and 50% wet basis (WB). The hammermill produced a more uniform particle size distribution in comparison to the shredder. Accessibility, indicated by conductivity index, to plant constituents, revealed that the method of treatment was not-significant …

A Highly Efficient Tio2-Xcx Nano-Heterojunction Photocatalyst For Visible-Light Induced Antibacterial Applications, Vinodkumar Etacheri, Michael Seery, Stephen Hinder, Georg Michlits, Suresh Pillai

Articles

Visible-light-induced antibacterial activity of carbon-doped anatase-brookite titania nano-heterojunction photocatalysts are reported for the first time. These heterostructures were prepared using a novel low temperature (100 °C) non-hydrothermal low power microwave (300 W) assisted method. Formation of interband C 2p states was found to be responsible for the band gap narrowing of the carbon doped heterojunctions. The most active photocatalyst obtained after 60 minutes of microwave irradiation exhibits a 2-fold higher visible-light induced photocatalytic activity in contrast to the standard commercial photocatalyst Evonik-Degussa P-25. Staphylococcus aureus inactivation rate constant for carbon-doped nano-heterojunctions and the standard photocatalyst was 0.0023 and -0.0081 min …

An Evaluation Of Seawater Pumped Hydro Storage For Regulating The Export Of Wind Energy To The National Grid, Eoin D. Mclean

Dissertations

Hydroelectric power generation has been in use for a very long time. From the earliest watermills to the current large scale Hydro power plants, this is a technology that is proven to be reliable and commercially viable. The use of wind energy to provide mechanical power for the purpose of turning a rotor is also not a new concept.Four years ago TCD Professor of Applied Physics Igor Shvets conceived the idea of solving Ireland’s energy crisis by taking these two proven renewable technologies and combining them. (McGreevey, 2012) The spirit of Ireland initiative seeks to resolve the biggest issues facing …

Synthesis And Characterization Of New Ionic And Mixed Ionic/Electronic Conductors, Kevin Gregory Romito

Theses and Dissertations

In a constantly growing and developing world, there is a great need to develop new forms of clean energy generation. Many solutions have been proposed to ameliorate these global concerns, which include fuel cell technology and new processes for reducing polluting chemicals in the atmosphere. These technologies are still in their infancy and require further development before becoming viable options.

In the case of fuel cells, particularly solid oxide fuel cells, and CO2 separation membranes, there is a need to develop ion conducting materials that are highly efficient, less costly to synthesize, and can perform strongly under many real-world conditions. …

Supercritical Co2 Brayton Cycles For Solar-Thermal Energy, Brian D. Iverson, Thomas M. Conboy, James J. Pasch, Alan M. Kruizenga

Faculty Publications

Of the mechanisms to improve efficiency for solar-­‐thermal power plants, one of the most effective ways to improve overall efficiency is through power cycle improvements. As increases in operating temperature continue to be pursued, supercritical CO2 Brayton cycles begin to look more attractive despite the development costs of this technology. Further, supercritical CO2 Brayton has application in many areas of power generation beyond that for solar energy alone.

One challenge particular to solar-­‐thermal power generation is the transient nature of the solar resource. This work illustrates the behavior of developmental Brayton turbomachinery in response to a fluctuating thermal input, much …

Control Of Smart Building Using Advanced Scada, Vivin Thomas Samuel

USF Tampa Graduate Theses and Dissertations

ABSTRACT

For complete control of the building, a proper SCADA implementation and the optimization strategy has to be build. For better communication and efficiency a proper channel between the Communication protocol and SCADA has to be designed.

This paper concentrate mainly between the communication protocol, and the SCADA implementation, for a better optimization and energy savings is derived to large scale industrial buildings. The communication channel used in order to completely control the building remotely from a distant place. For an efficient result we consider the temperature values and the power ratings of the equipment so that while controlling the …

Energy Harvesting Of Human Kinetic Movement, David Marusiak, Julia Carrillo

Electrical Engineering

Development of kinetic energy scavenging applications from the human body necessitates additional research to assist in designating a mounting position for a potential device. A data acquisition system adequately provides a parametric average power comparison among four locations on the body (waist, upper arm, hand, and calf) for both a male and female subject. Experimentally, the hand-held device provided the highest average power. Thus, subsequent investigation at set speeds provides further analysis of the output’s characteristically linear behavior. The physical energy-harvesting device features a plastic tube casing wrapped with the stationary coiled wire through which a neodymium magnet oscillates. While …

The Impact Of Advanced Wastewater Treatment Technologies And Wastewater Strength On The Energy Consumption Of Large Wastewater Treatment Plants, Timothy Stephen Newell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Wastewater treatment is an energy intensive process often requiring the use of advanced treatment technologies. Stricter effluent standards have resulted in an increase in the number of wastewater treatment plants (WWTPs) with advanced treatment over time. Accordingly, associated energy consumption has also increased. Concerns about lowering operating costs for WWTPs and reducing associated greenhouse gas generation present an incentive to investigate energy use in WWTPs. This research investigated the impact of wastewater strength and the introduction of advanced treatment technologies, to replace traditional technologies on energy use to treat wastewater in WWTPs. Major unit processes were designed for a 100 …

An Energy Survey Of The Church Lane Building At Dit, Joseph Teehan

Other resources

Within the European Union, the collective governments have introduced broad energy policies in order to increase energy efficiency and improve energy performance in new and existing buildings, within each member state. The following dissertation considers energy and how energy is used within the context of global and local consumption in an extensive literature review. Where does the future lie for Ireland and its energy sources? Policies, standards and regulations associated with energy efficiency and the Energy Performance of Buildings Directive (EPBD) are defined and briefly explained. The status of how well the response from the commercial building market to Building …

Technology Portal For Energy Efficient Buildings, Larry D. Hermanson, Daniel Studer, Annie Mroz

STAR Program Research Presentations

Project: Technology Portal for Energy Efficient Buildings

Date: August 2, 2012

Author: Larry Hermanson

Mentor: Daniel Studer

Cohort: Annie Mroz

Lab site: National Renewable Energy Laboratory (NREL)

Buildings account for 71% of the electricity demand and 39% of the primary energy consumption in the United States. The Commercial Buildings Group at NREL provides builders, designers and building owners accurate information to significantly improve the energy efficiency of new and existing buildings. The Technology Portal for Energy Efficient Buildings will increase the accessibility of standardized and credible energy performance data for all building systems, thereby allowing building owners to better evaluate …

Thermo-Mechanical Modeling Of The Electrically-Assisted Manufacturing (Eam) Technique During Open Die Forging, Wesley Salandro

All Dissertations

This thesis contains all of the steps which allow the Electrically-Assisted Manufacturing (EAM) technique to be experimentally explored and analytically modeled for an electrically-assisted forging operation. Chapter 1 includes the problem statement, proposed solution, and literature reviews on EAM. Chapter 2 describes a thorough background on the EAM technique, highlights prior EAM research, and explains the research approach taken for this thesis. The coupled thermo-mechanical modeling strategy, along with the introduction of the Electroplastic Effect Coefficient (EEC) is provided in Chapter 3. Chapter 4 explains the two different approaches to determine the EEC profiles when modeling a particular metal. The …

Solar Light Bulb, David G. Guzman, Virgilio Gonzalez

COURI Symposium Abstracts, Summer 2012

The Solar Lighting project is a work driven towards building a low-cost and environmental-friendly solar bulb and to understanding the science behind its behavior. A solar light bulb refers to a device capable of absorbing and transferring solar energy to light up an enclosed area. By using the physical properties of fluids and light is possible to manipulate solar light waves to illuminate an enclosed structure. Moreover, this project attempts to utilize recycled materials that reduce the cost of such device, helping not only the planet but also the costumer’s pocket. The ultimate goal for this project is to scientifically …

Power Tac 2012: Agent Technologies For The Smart Grid, Carlos E. Montijo, Daniel H. Grajeda, Christopher Kiekintveld

COURI Symposium Abstracts, Summer 2012

Intelligent agents are a critical technology in managing the increasingly complex and decentralized energy systems that are evolving. These technologies, often called the "smart grid," have the potential to improve the efficiency and reliability of future energy markets. This project focuses on developing a trading agent to compete in the 2012 Power TAC game, a new scenario this year that is part of the annual Trading Agent Competition. Modeling a liberalized retail electrical energy market, Power TAC is a simulation in which competing trading agents or brokers offer energy services to customers via tariff contracts. The brokers must also serve …

Advanced Intelligent Control And Optimization For Cardiac Pacemaker Systems, Wei Shi

Dissertations

Since cardiovascular diseases are major causes of morbidity and mortality in the developed countries and the number one cause of death in the United States, their accurate diagnosis and effective treatment via advanced cardiac pacemaker systems have become very important. Intelligent control and optimization of the pacemakers are significant research subjects. Serious but infrequently occurring arrhythmias are difficult to diagnose. The use of electrocardiogram (ECG) waveform only cannot exactly distinguish between deadly abnormalities and temporary arrhythmias. Thus, this work develops a new method based on frequency entrainment to analyze pole-zero characteristics of the phase error between abnormal ECG and entrained …

Modeling And Analysis Of A Photovoltaic System With A Distributed Energy Storage System, Anthony Winston Ma

Master's Theses

As California continues to integrate more renewable energy into its electrical system, the state has experienced a corresponding rise in photovoltaic system installations. PV arrays are a unique source of power generation in that they are affected by the location of the sun, shading, and temperature changes. These characteristics make solar one of the most highly variable forms of renewable energy. In order to improve solar power’s consistency, PV systems require a supplemental source of power. The primary focus of this paper is to determine if distributed energy storage systems can be used to reduce the effect of solar intermittency. …

Assessing The Engineering Performance Of Affordable Net-Zero Energy Housing, Jordan P. Wallpe

Purdue Polytechnic Masters Theses

The purpose of this research was to evaluate affordable technologies that are capable of providing attractive, cost-effective energy savings to the housing industry. The research did so by investigating the 2011 Solar Decathlon competition, with additional insight from the Purdue INhome. Insight from the Purdue INhome verified the importance of using a three step design process to design a net-zero energy building. In addition, energy consumption values of the INhome were used to compare and contrast different systems used in other houses.

Evaluation of unbiased competition contests gave a better understanding of how a house can realistically reach net-zero. Upon …

Heterogeneous Water And Energy End-Uses And Implications For Residential Water And Energy Conservation And Management, Adel M. Abdallah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Indoor water-use consumes energy to heat hot water. Indoor water- and energy-use vary significantly among households due to variable household water-use behaviors and varying ages and efficiencies of water appliances. Also, the energy consumed to heat water varies among households and depends on water heater efficiency, heater thermostat setup, percentage of hot water in the final used water, and the cold water intake temperature. This research considers behavioral and technological variability in household water-and-energy-use to better understand water and energy linkages and help utilities target water and energy conservation actions to customer and appliances within their homes that the most …

Computational Models Of Sub-Divided Thermal Energy Storage Tanks Used In Concentrating Solar Power Plants With Parabolic Trough Collectors, Jesus D. Ortega ^, Vinod Kumar *

COURI Symposium Abstracts, Spring 2012

No abstract provided.