Engineering Commons^™

Hvac System Energy Audit For Leverett Elementary School, Connor Smalling

Biological and Agricultural Engineering Undergraduate Honors Theses

Leverett Elementary School is located in Fayetteville, AR. The school needs significant upgrades to its infrastructure. The Fayetteville Public School District has voted to pursue an Energy Services Performance Contract (ESPC) in order to finance the desired upgrades to Leverett Elementary, among other schools in the district.

The scope of this thesis was to perform an energy audit on the existing heating, ventilation, and air conditioning (HVAC) system. By using an energy modeling software, eQuest, the building and the existing base system were modeled to determine utility consumption. Three different HVAC system alternatives were analyzed against the base system by …

Software-Defined Infrastructure For Iot-Based Energy Systems, Stephen Lee

Doctoral Dissertations

Internet of Things (IoT) devices are becoming an essential part of our everyday lives. These physical devices are connected to the internet and can measure or control the environment around us. Further, IoT devices are increasingly being used to monitor buildings, farms, health, and transportation. As these connected devices become more pervasive, these devices will generate vast amounts of data that can be used to gain insights and build intelligence into the system. At the same time, large-scale deployment of these devices will raise new challenges in efficiently managing and controlling them. In this thesis, I argue that the IoT …

Sustainable Travel Incentives Optimization In Multimodal Networks, Hossein Ghafourian

Masters Theses

Tripod, an integrated bi-level transportation management system, is a smartphone application from the potential user’s point of view which would be instantly accessed prior to performing the trip. Since there are constantly several alternatives for any trip, Tripod considers a series and combination of various parameters, including departure time, mode and route, and rewards for each alternative with a number of redeemable points for goods and services called “Tokens”. The framework responsible for computing the optimized number of tokens awarded to the set of available alternatives in order to minimize the system-wide energy consumption under a constrained Token budget, is …

Design And Measurement Of Strongarm Comparators, Nathan Robert Whitehead

Theses and Dissertations

The StrongARM comparator is utilized in many analog-to-digital converters (ADCs) because of its high power efficiency and rail-to-rail outputs. The performance of the comparator directly affects the speed, power, and accuracy of an ADC. However, the StrongARM comparator performance parameters such as delay, noise, and offset measured directly from silicon prototypes are rare in literature and often consist of small sample sets. In addition, existing techniques to measure the comparator require large chip areas, making it impractical to characterize a large number of comparators to obtain stochastic parameters such as offset and noise. This work presents novel circuit techniques to …

Passive Control Of Structures, Feti Selmani

UBT International Conference

Lately, powerful earthquakes stroke some parts of the world, while the Balkan Peninsula was hit by moderate ones. During a powerful earthquake, a building structure is invaded by an enormous quantity of kinetic energy . As far as the manner is concerned, this energy it is initially absorbed, and thereafter distributed throughout building structure relying not only to the reaction of structure as a whole, or structural elements in particular, but the nature, the distribution and the quantity of the damages also. As Nikola Tesla once quoted:“If you want to find the secrets of universe, think in terms of energy, …

Analysis Of Design And Efficiency Of Absorbtion Refrigerating Machines, K.F. Karimov, N.S. Zakirova, Sh.V. Muminov, J.J. Axmedov

Chemical Technology, Control and Management

The results of analysis of designs and efficiency of absorption refrigerating machines are considered. Based on the analysis of schemes and designs of modern absorption refrigerating machines used for obtaining cold at various levels, the main characteristic parameters of refrigeration equipment are given, their capabilities and disadvantages are indicated. Methods for evaluating the efficiency of absorption columns and machines are analyzed. It is proposed to study the absorption column as part of the refrigeration machine, as well as to evaluate the efficiency of heat and mass transfer devices, machines exergetic method.

Wireless Rf Induced Energy Absorption And Heating Of Lanthanum-Nickel Alloy In The Near-Field, Michael Dillon Lindsay

Theses and Dissertations

This thesis will investigate whether and how a synthetic metal-magnetic alloy absorbs enough near-field electromagnetic (EM) radiation for heating. Although resistive elements could be used for indirect heating, a wireless radio frequency (RF) method is explored because of its advantages in its non-intrusive nature and its ability to direct or focus energy within a specific area. For our case, the RF heating process relies on the materials ability to absorb sufficient RF energy due to the induced currents. We expect there to be significant surface resistance due to the conductivity and magnetic permeability of the material and thus heat. This …

Our Energy Future, Fall/Winter 2007, Issue 15

Sustain Magazine

No abstract provided.

Unconventional Energy, Fall/Winter 2015, Issue 31

Sustain Magazine

No abstract provided.

Investigation Of Efficiency Loss Of Distributed Solar Power Due To Soiling And Efficiency Recovery By Rainfall, Amanda Mayumi Tanaka

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the concern with global warming increases causing the need for CO2 reduction, renewable energy is of great interest as it has lower carbon footprint when compared to conventional sources (natural gas, coal, oil and nuclear). Solar energy has been drawing worldwide attention since it can transform sunlight directly into electricity with the use of photovoltaic (PV) cells. However, this technology has some drawbacks that need to be addressed including dust deposition on solar panels, also known as soiling. Soiling can decrease PV panel’s efficiency thereby resulting in less energy production. The soiling rates are very site specific and depend …

Isentropic Efficiency And Theoretical Analysis Of The Planetary Rotor Expander, Joseph L. James

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Expanders allow pressurized fluids to undergo a pressure decrease in a controlled environment via volumetric growth to extract fluid energy. There are many types of expanders, and the objective of this thesis is to model the efficiencies of the planetary rotor expander (PRE), a century-old design undeveloped due to insufficient manufacturing capabilities (until recently). Geometric relationships are derived and mathematical models are generated to determine the efficiency of the PRE as a function of design variables. Two industrially relevant case studies show that, to maximize isentropic efficiency, the planetary rotor expander (PRE) rotational frequency is maximized and rotor geometry optimized.

Swarm Behavior To Mitigate Rebound In Air Conditioning Demand Response Events, Jason Yasuto Kuwada

Boise State University Theses and Dissertations

Thermostatically Controlled Loads (TCLs) have shown great potential for Demand Response (DR) events. However, it has been commonly seen that DR events using TCLs may cause demand rebound, especially in homogeneous populations. To further explore the potential for DR events, as well as the negative effects, a stability and resilience analysis were performed on multiple populations and verified with agent based modeling simulations.

At the core of this study is an added thermostat criterion created from the combination of a proportional gain and the average compressor operating state of neighboring TCLs. Where DR events in TCLs are commonly controlled by …

Ultraefficient Thermophotovoltaic Power Conversion By Band-Edge Spectral Filtering, Z. Omair, G. Scranton, L. M. Pazos-Outón, T. P. Xiao, M. A. Steiner, Vidya Ganapati, P. F. Peterson, J. Holzrichter, H. Atwater, E. Yablonovitch

Engineering Faculty Works

Thermophotovoltaic power conversion utilizes thermal radiation from a local heat source to generate electricity in a photovoltaic cell. It was shown in recent years that the addition of a highly reflective rear mirror to a solar cell maximizes the extraction of luminescence. This, in turn, boosts the voltage, enabling the creation of record-breaking solar efficiency. Now we report that the rear mirror can be used to create thermophotovoltaic systems with unprecedented high thermophotovoltaic efficiency. This mirror reflects low-energy infrared photons back into the heat source, recovering their energy. Therefore, the rear mirror serves a dual function; boosting the voltage and …

Energy Transformation And Conservation Investigation, Mike Jackson, Holly Haney

High School Lesson Plans

Students will use a thermoelectric generator module to analyze the relationship between thermal and electrical energies. Using data collection sensors and analysis software, students will investigate the relationship between the temperature gradient across a thermoelectric generator module and the resulting electrical potential. Students will then use their data and analysis to solve problems relating to waste thermal energy in electrical systems and communicate their work to their peers and teacher.

Evaluating The Potential For Renewable Energy Technology At Us Ski Resorts, Tyler Farrell

ENGS 86 Independent Projects (AB Students)

The ski industry is one of the most at-risk industries as a result of climate change. Warming temperatures and decreasing snowfall are contributing to a decline in skier visitations, shorter seasons, and higher energy costs. Currently, only 3 of 478 ski resorts in the United States rely on 100% renewable energy sources. The intent of this paper is to understand what the issues and barriers are to renewable energy development at ski resorts, and what technologies are feasible and appropriate for this industry to develop. While the renewable energy industry faces many issues and barriers, the ski industry faces its …

Feasibility Study Of Dartmouth's Renewable Energy Future, Lily R. Hanig

ENGS 88 Honors Thesis (AB Students)

This is a feasibility study of Dartmouth's Renewable Energy propositions. This study analyzes the carbon offsets of implementing a 13 MW solar PV system at Oak Hill. This study used the Energy Database to calculate the carbon emissions of the college for 2010 (the baseline year) and 2018. It also projected carbon emissions for the year 2025 assuming the Oak Hill solar PV system is implemented as outlined and the biomass plant is implemented with similar fuel ratios to nearby biomass plant projects. It was found that Dartmouth should sufficiently make its carbon emissions reductions goals for 2025.

Numerical Investigation Of Coalescence-Induced Self-Propelled Behavior Of Droplets On Non-Wetting Surfaces And Wedged Surfaces., Yan Chen

Electronic Theses and Dissertations

When small drops coalesce on a superhydrophobic surface, the merged drop can jump away from the surface due to the surface energy released during the coalescence. This self-propelled behavior has been observed on various superhydrophobic surfaces and has potential applications in areas related to the heat and mass transfer, such as heat exchangers, anti-icing and anti-frost devices, thermal management and water harvesting. The jumping velocity model was obtained based on published experimental data and the balance of various energy terms described in previous studies. However, the self-propelled mechanism is still not fully understood. In this study, the self-propelled droplet phenomenon …

Effects Of Disorder On Thermoelectric Properties Of Semiconducting Polymers, Zlatan Aksamija, Dhandapani Venkataraman, Connor J. Boyle, Meenakshi Upadhyaya

Zlatan Aksamija

Energy Consumption And Routing Model For First Responder Vehicles, Alex Rodriguez

The Pegasus Review: UCF Undergraduate Research Journal

The ongoing research and prototyping of electric vehicles (EVs) offers numerous opportunities to investigate their performance in various service contexts. As EVs are integrated into society, the reliable prediction of fuel consumption and routing time becomes particularly important in emergency response services. This project develops a preliminary stochastic model that can route and predict the energy consumption and travel time for hypothetical emergency vehicles operating on an electric battery cell. Using a Monte-Carlo framework, we constructed a routing model designed to minimize travel time and resource consumption under various simulated conditions. In doing so, we establish the foundation for balancing …

Open Source Low-Cost Power Monitoring System, Shane W. Oberloier, Joshua M. Pearce

Joshua M. Pearce

This study presents an entirely open-source, low-cost power monitoring system capable of many types of measurements including both loads and supplies such as solar photovoltaic systems. In addition, the system can be fabricated using only open source software and hardware. The design revolves around the Digital Universal Energy Logger (DUEL) Node, which is responsible for reading and properly scaling the voltage and current of a particular load, and then serializing it via an on-board ATTiny85 chip. The configuration of the DUEL node allows for custom sensitivity ranges, and can handle up to 50 A and 300 V. Up to 127 …

Microgrid Renewable Energy Integration, Do Quang Thanh Vo

Electrical Engineering

The Microgrid is a small-scale electrical system that is designed to give Cal Poly students hands-on experience on power generation, system protection, distribution, and automation that would otherwise be very difficult to experiment in a large-scale model.

To closely replicate the modern electrical grid, a renewable energy source shall be added to the Microgrid in conjunction with the existing synchronous generators. Electrical engineering student, Virginia Yan initiated this effort, namely Grid-Tied Solar System project [1], by designing and constructing a set of solar panels and microinverter for future connection to the Microgrid. The scope of Virginia’s project was, however, limited …

An Analysis Of Energy Transitions At Different Scales: Fossil Fuel Divestment In Higher Education And Individual Behavior, Elizabeth Palchak

Graduate College Dissertations and Theses

A sociotechnical energy transition requires both a shift to new technologies and attention to social issues like political movements, policy and human behavior. This dissertation investigates social elements of the renewable energy transition occurring at different scales. The core research questions are: How are universities creating and responding to the shifting language of fossil fuel investments? How and for whom do behavioral interventions work? And finally, do in-home displays (IHDs) change behaviors and attitudes of millennial energy users?

The three studies covered here occurred within higher education and reflect the importance of colleges and universities as dynamic players in energy …

Solar Tracker Renewable Energy, Stephanie Christie, Annabeth Helmly, Matthew Smith, Katrina Vaughan

ENERGY Research and Lesson Plans

No abstract provided.

Energy Lesson Design, Jessica Lyons

ENERGY Research and Lesson Plans

No abstract provided.

(Bi0.51 Na0.47)Tio3 Based Lead Free Ceramics With High Energy Density And Efficiency, Yu Huang, Fei Li, Hua Hao, Fangquan Xia, Hanxing Liu, Shujun Zhang

Australian Institute for Innovative Materials - Papers

Dielectric ceramics with high energy storage density and energy efficiency play an important role in high power energy storage applications. In this work, lead free relaxor ferroelectric ceramics in (1-x)Bi 0.51 Na 0.47 TiO 3 - xBa(Zr 0.3 Ti 0.7 )O 3 (BNT-BZT100x: x = 0.20, 0.30, 0.40 and 0.50) system are fabricated by conventional solid-state sintering method. The BNT-BZT100x ceramics are sintered dense with minimal pores, exhibiting pseudocubic symmetry and strong relaxor characteristic. A high energy storage density of 3.1 J/cm 3 and high energy efficiency of 91% are simultaneously achieved in BNT-BZT40 ceramic with 0.1 mm in thickness, …

Coupling Topological Insulator Snsb2te4 Nanodots With Highly Doped Graphene For High-Rate Energy Storage, Zhibin Wu, Gemeng Liang, Wei Kong Pang, Tengfei Zhou, Zhenxiang Cheng, Wenchao Zhang, Ye Liu, Bernt Johannessen, Zaiping Guo

Australian Institute for Innovative Materials - Papers

Topological insulators have spurred worldwide interest, but their advantageous properties have scarcely been explored in terms of electrochemical energy storage, and their high-rate capability and long-term cycling stability still remain a significant challenge to harvest. p-Type topological insulator SnSb2Te4 nanodots anchoring on few-layered graphene (SnSb2Te4/G) are synthesized as a stable anode for high-rate lithium-ion batteries and potassium-ion batteries through a ball-milling method. These SnSb2Te4/G composite electrodes show ultralong cycle lifespan (478 mAh g−1 at 1 A g−1 after 1000 cycles) and excellent rate capability (remaining 373 mAh g−1 even at 10 A g−1) in Li-ion storage owing to the rapid …

Performance Simulation And Evaluation Of Net Zero Energy Buildings In An Australian Coastal Climate, Joel Anderson, Duane A. Robinson, Zhenjun Ma

Faculty of Engineering and Information Sciences - Papers: Part B

Net zero energy buildings (NZEB) are becoming more common, and as new energy saving designs and technologies become available, the ability to estimate overall energy use and understand the impact on operation of building appliances will become important. This paper outlines simulation results of performance improvements achieved by modifying various components (glazing, lighting, thermal comfort settings) of two tertiary education NZEBs and a typical modern commercial building. The DesignBuilder models' thermal performance and energy consumption were validated using real data from case study buildings. The work shows validating models of smaller, less conven-tional, buildings is more difficult than for larger …

A Method Of Uncertainty Analysis For Whole-Life Embodied Carbon Emissions (Co2-E) Of Building Materials Of A Net-Zero Energy Building In Australia, Mehdi Robati, Daniel J. Daly, Georgios Kokogiannakis

Faculty of Engineering and Information Sciences - Papers: Part B

The construction of new buildings requires the use of a substantial amount of materials, which have an associated embodied energy for manufacturing, transport, construction and end-of-life disposal. A number of inventories have been developed to collate the typical embodied energy or carbon emissions associated with different building materials and activities, and these can be used to quantify the environmental impacts of different construction methods. However, uncertainty exists in the estimation of embodied CO2-e emissions and other environmental impact results, due to i) inconsistencies in typical embodied carbon emissions values in inventories; ii) errors in estimations of material quantities; iii) assumptions …

Study On Performance Evaluation Of Co2 Heat Pump System Integrated With Thermal Energy Storage For Space Heating, Zhihua Wang, Yuxin Zheng, Fenghao Wang, Mengjie Song, Zhenjun Ma

Faculty of Engineering and Information Sciences - Papers: Part B

CO2 heat pumps have drawn a great deal of attention owing to their advantages of high efficiency and environmental friendly for heating water under low ambient temperature. However, the system performance is not desirable and shows a lower COP for space heating, especially for a radiator as heating terminal, due to the higher inlet water temperature at the gas cooler, which causes a large throttle loss when the refrigerant flow through the throttling device. To tackle this issue, a transcritical CO2 heat pump system integrated with thermal energy storage (TES) systems was developed in this paper. The heating performance of …

Full-Duplex Ofdm Relaying Systems With Energy Harvesting In Multipath Fading Channels, Jiaman Li, Le Chung Tran, Farzad Safaei

Faculty of Engineering and Information Sciences - Papers: Part B

In this paper, the performance of in-band fullduplex OFDM relaying systems with energy-harvesting and selfinterference cancellation in the polarization domain is analyzed. Specifically, we use the time switching-based relaying protocol to implement energy harvesting. The harvested energy is used by the relay to forward the transmitted information from the source. To cancel the self-interference, the polarization-enabled digital self-interference cancellation scheme is deployed at the relay. Our simulation results show that the full-duplex OFDM energy harvesting relaying system almost doubles the throughput, while maintaining the same bit error performance by a modest increase in the signal-to-noise ratio compared to the half-duplex …