Matching Items (198)
Description
District heating plays an important role in improving energy efficiency and providing thermal heat to buildings. Instead of using water as an energy carrier to transport sensible heat, this dissertation explores the use of liquid-phase thermochemical reactions for district heating as well as thermal storage. Chapters 2 and 3 present thermodynamic and design analyses for the proposed district heating system. Chapter 4 models the use of liquid-phase thermochemical reactions for on-site solar thermal storage. In brief, the proposed district heating system uses liquid-phase thermochemical reactions to transport thermal energy from a heat source to a heat sink. The separation ensures that the stored thermochemical heat can be stored indefinitely and/or transported long distances. The reactant molecules are then pumped over long distances to the heat sink, where they are combined in an exothermic reaction to provide heat. The product of the exothermic reaction is then pumped back to the heat source for re-use. The key evaluation parameter is the system efficiency.
The results demonstrate that with heat recovery, the system efficiency can be up to 77% when the sink temperature equals 25 C. The results also indicate that the appropriate chemical reaction candidates should have large reaction enthalpy and small reaction entropy. Further, the design analyses of two district heating systems, Direct District Heating (DDH) system and Indirect District Heating (IDH) system using the solvated case shows that the critical distance is 106m. When the distance is shorter than 1000,000m, the factors related to the chemical reaction at the user side and factors related to the separation process are important for the DDH system. When the distance is longer than 106m, the factors related to the fluid mechanic become more important. Because the substation of the IDH system degrades the quality of the energy, when the distance is shorter than 106m, the efficiency of the substation is significant. Lastly, I create models for on-site solar thermal storage systems using liquid-phase thermochemical reactions and hot water. The analysis shows that the thermochemical reaction is more competitive for long-duration storage applications. However, the heat recovery added to the thermochemical thermal storage system cannot help improving solar radiation absorption with high inlet temperature of the solar panel.
ContributorsZhang, Yanan (Author) / Wang, Robert (Thesis advisor) / Milcarek, Ryan (Committee member) / Parrish, Kristen (Committee member) / Phelan, Patrick (Committee member) / Rykaczewski, Konrad (Committee member) / Arizona State University (Publisher)
Created2022
Description
Energy storage technologies are essential to overcome the temporal variability in renewable energy. The primary aim of this thesis is to develop reactor solutions to better analyze the potential of thermochemical energy storage (TCES) using non-stoichiometric metal oxides, for the multi-day energy storage application. A TCES system consists of a reduction reactor and an insulated MOx storage bin. The reduction reactor heats (to ~ 1100 °C) and partially reduces the MOx, thereby adding sensible and chemical energy (i.e., charging it) under reduced pO2 environments (~10 Pa). Inert gas removes the oxygen generated during reduction. The storage bin holds the hot and partially reduced MOx (typically particles) until it is used in an energy recovery device (i.e., discharge). Irrespective of the reactor heat source (here electrical), or the particle-inert gas flows (here countercurrent), the thermal reduction temperature and inert gas (here N2) flow minimize when the process approaches reversibility, i.e., operates near equilibrium. This study specifically focuses on developing a reduction reactor based on the theoretical considerations for approaching reversibility along the reaction path. The proposed Zigzag flow reactor (ZFR) is capable of thermally reducing CAM28 particles at temperatures ~ 1000 °C under an O2 partial pressure ~ 10 Pa. The associated analytical and numerical models analyze the reaction equilibrium under a real (discrete) reaction path and the mass transfer kinetic conditions necessary to approach equilibrium. The discrete equilibrium model minimizes the exergy destroyed in a practical reactor and identifies methods of maximizing the energy storage density () and the exergetic efficiency. The mass transfer model analyzes the O2 N2 concentration boundary layers to recommend sizing considerations to maximize the reactor power density. Two functional ZFR prototypes, the -ZFR and the -ZFR, establish the proof of concept and achieved a reduction extent, Δδ = 0.071 with CAM28 at T~950 °C and pO2 = 10 Pa, 7x higher than a previous attempt in the literature. The -ZFR consistently achieved > 100 Wh/kg during >10 h. runtime and the -ZFR displayed an improved = 130 Wh/kg during >5 h. operation with CAM28. A techno-economic model of a grid-scale ZFR with an associated storage bin analyzes the cost of scaling the ZFR for grid energy storage requirements. The scaled ZFR capital costs contribute < 1% to the levelized cost of thermochemical energy storage, which ranges from 5-20 ¢/kWh depending on the storage temperature and storage duration.
ContributorsGhotkar, Rhushikesh (Author) / Milcarek, Ryan (Thesis advisor) / Ermanoski, Ivan (Committee member) / Phelan, Patrick (Committee member) / Wang, Liping (Committee member) / Wang, Robert (Committee member) / Arizona State University (Publisher)
Created2023
Description
The conversion of H2S enables the recycling of a waste gas into a potential source of hydrogen at a lower thermodynamic energy cost as compared to water splitting. However, studies on the photocatalytic decomposition of H2S focus on traditional deployment of catalyst materials to facilitate this conversion, and operation only when a light source is available. In this study, the efficacy of Direct Ink Written (DIW) luminous structures for H2S conversion has been investigated, with the primary objective of sustaining H2S conversion when a light source has been terminated. Additionally, as a secondary objective, improving light distribution within monoliths for photocatalytic applications is desired. The intrinsic illumination of the 3D printed monoliths developed in this work could serve as an alternative to monolith systems that employ light transmitting fiber optic cables that have been previously proposed to improve light distribution in photocatalytic systems. The results that were obtained demonstrate that H2S favorable adsorbents, a wavelength compatible long afterglow phosphor, and a photocatalyst can form viscoelastic inks that are printable into DIW luminous monolithic contactors. Additionally, rheological, optical and porosity analyses conducted, provide design guidelines for future studies seeking to develop DIW luminous monoliths from compatible catalyst-phosphor pairs. The monoliths that were developed demonstrate not only improved conversion when exposed to light, but more significantly, extended H2S conversion from the afterglow of the monoliths when an external light source was removed. Lastly, considering growing interests in attaining a global circular economy, the techno-economic feasibility of a H2S-CO2 co-utilization plant leveraging hydrogen from H2S photocatalysis as a feed source for a downstream CO2 methanation plant has been assessed. The work provides preliminary information to guide future chemical kinetic design characteristics that are important to strive for if using H2S as a source of hydrogen in a CO2 methanation facility.
ContributorsAbdullahi, Adnan (Author) / Andino, Jean (Thesis advisor) / Phelan, Patrick (Thesis advisor) / Bhate, Dhruv (Committee member) / Wang, Robert (Committee member) / Huang, Huei-Ping (Committee member) / Arizona State University (Publisher)
Created2023
Description
Thermal susceptibility is one of the biggest challenges that asphalt pavements must overcome. Asphalt mixture’s thermal susceptibility can increase problems related to permanent deformation, and the expansion-contraction phenomenon triggers thermal cracking. Furthermore, there is a common worldwide interest in environmental impacts and pavements. Saving energy and mitigating the urban heat island (UHI) effect have been drawing the attention of researchers, governments, and industrial organizations. Pavements have been shown to play an important role in the UHI effect. Globally, about 90% of roadways are made of asphalt mixtures. The main objective of this research study involves the development and testing of an innovative aerogel-based product in the modification of asphalt mixtures to function as a material with unique thermal resistance properties, and potentially providing an urban cooling mechanism for the UHI. Other accomplishments included the development of test procedures to estimate the thermal conductivity of asphalt binders, the expansion-contraction of asphalt mixtures, and a computational tool to better understand the pavement’s thermal profile and stresses. Barriers related to the manufacturing and field implementation of the aerogel-based product were overcome. Unmodified and modified asphalt mixtures were manufactured at an asphalt plant to build pavement slabs. Thermocouples installed at top and bottom collected data daily. This data was valuable in understanding the temperature fluctuation of the pavement. Also, the mechanical properties of asphalt binders and mixtures with and without the novel product were evaluated in the laboratory. Fourier transform infrared (FTIR) and scanning electron microscope (SEM) analyses were also used to understand the interaction of the developed product with bituminous materials.
The modified pavements showed desirable results in reducing overall pavement temperatures and suppressing the temperature gradient, a key to minimize thermal cracking. The comprehensive laboratory tests showed favorable outcomes for pavement performance. The use of a pavement design software, and life cycle/cost assessment studies supported the use of this newly developed technology. Modified pavements would perform better than control in distresses related to permanent deformation and thermal cracking; they reduce tire/pavement noise, require less raw material usage during their life cycle, and have lower life cycle cost compared to conventional pavements.
ContributorsObando Gamboa, Carlos Javier (Author) / Kaloush, Kamil (Thesis advisor) / Mamlouk, Michael (Committee member) / Ozer, Hasan (Committee member) / Fini, Elham (Committee member) / Zapata, Claudia (Committee member) / Arizona State University (Publisher)
Created2022
Description
The propulsion matrix provides a compact description of the locomotion of a single flagella molecular motor in a low Reynolds number environment. The locomotion properties of individual flagellar motors are central to bacterial behavior, including chemotaxis, pathogenesis, and biofilm formation. However, because conventional hydrodynamic measurement approaches require applied forces, torques, or fluid flows, it is not possible to directly measure the propulsion matrix for an individual microscale helical filament. Here, the limitations inherent to conventional measurement approaches are overcome using a combination of theoretical, experimental, and computational advancements. First, the relationship between the elements of the propulsion matrix with translational and rotational Brownian motion is derived using the fluctuation-dissipation theorem. Next, a volumetric fluorescent imaging using high resolution oblique plane microscopy with sufficient spatio-temporal resolution is conducted to resolve both translation and rotation of individual helical filaments isolated from E.coli's flagellar motor. Finally, a computational framework is developed to track individual helical filaments across six degrees of freedom, extract diffusion coefficients, and quantify the temporal correlation between translation and rotation. This study computed the maximum propulsion efficiency to be around 1.7%. Direct measurement of propulsion efficiency generally agrees with the ensemble and large-scale measurements previously performed using conventional hydrodynamic measurements. The findings suggest that the approach described here can be extended to more complex in-vitro experiments that evaluate microscale molecular motors. For example, evaluating sperm motility without inducing chemotaxis or utilizing a microfluidic setup.
ContributorsDjutanta, Franky (Author) / Hariadi, Rizal (Thesis advisor) / Wang, Robert (Thesis advisor) / Yurke, Bernard (Committee member) / Herrmann, Marcus (Committee member) / Huang, Huei-Ping (Committee member) / Arizona State University (Publisher)
Created2022
Description
Radiation heat transfer can surpass blackbody limit when distance between the hot emitter and cold receiver is less than the characteristic wavelength of electromagnetic radiation. The enhanced radiation heat transfer achieved is also called near-field radiation heat transfer. Several theoretical and experimental studies have demonstrated enhancement in near-field radiation heat transfer for isotropic materials such as silicon carbide (SiC), undoped and doped Si. The enhancement achieved however is narrow-banded. Significant improvement in radiation heat transfer is necessary to satisfy some of the energy demands. So, there is a growing interest to use hyperbolic materials because of its enhancement due to propagating modes. The main objective of the current thesis project is to investigate the control of hyperbolic bands using boron nitride nanotubes (nanostructure of hexagonal boron nitride) for near-field radiative heat transfer. Optical properties of boron nitride nanotubes are calculated using Maxwell-Garnet’s effective medium theory and its corresponding hyperbolic bands are identified. It is observed that the boron nitride nanotubes have only one hyperbolic band located at higher frequencies. Preliminary comparisons of the near-field radiative heat flux calculations with literature are performed using a more general 4×4 transfer matrix method. Due to its high computational time, anisotropic thin film optics is used to calculate near-field radiative heat transfer. Factors contributing to enhancement is investigated. In the end, Spectral allocation ratio, the ratio of heat flux contributed from higher frequencies to the heat flux contributed from lower frequencies is calculated to assess the contribution of each hyperbolic band to total heat flux.
ContributorsRajan, Vishwa Krishna (Author) / Wang, Liping (Thesis advisor) / Phelan, Patrick (Committee member) / Wang, Robert (Committee member) / Arizona State University (Publisher)
Created2022
Description
A successful implementation of a Pavement Management System (PMS) allows agencies to make objective and informed decisions in maintaining their pavement assets effectively. Since 2008, the City of Phoenix, Arizona, has implemented PMS to maintain approximately 7,725 km (4,800 mi) of pavements. PMS is not a static system but a dynamic system requiring regular updates to reflect pavement performance and meet the agency's goals and budget. After upgrading to the Automated Road Analyzer (ARAN) 9000 in 2017, there is a need for Phoenix to evaluate its PMS. A low pavement condition index (PCI) for newly paved roads and the requirements for more than 35% of scheduled fog seal projects to be upgraded to heavier treatments observed, also motivated this research effort. The scope of this research was limited to the flexible pavement preservation program and the objectives are: (1) to evaluate the effectiveness of the existing City of Phoenix PMS and (2) to recommend improvements to the existing PMS.
This study evaluated technical and non-technical aspects of Phoenix’s preservation program. Since pavements in a structurally sound condition are good candidates for preservation treatment, a single pavement performance indicator, which allows agencies to be more flexible with their preservation treatments and minimize the pavement performance data collection and modeling efforts, was explored. A simple yet measurable and trackable pavement performance indicator, Surface Cracking Index (SCI), representing the overall pavement condition to perform PMS analysis for a preservation program, was proposed.
In addition, using a performance indicator, the International Roughness Index (IRI) to represent the ride quality or roughness, is a challenge for many local governments due to the nature of urban roadway related conditions such as stop and go driving conditions, abrupt lane change maneuvering, and lower prevailing speed. Therefore, a surface roughness indicator, Mean Profile Depth (MPD) measuring pavement surface macrotexture, was explored, and is proposed to be integrated in the PMS to optimize preservation treatments and recommendation strategies.
While Phoenix will directly benefit from this research study outcomes, any agency who uses PMS, or plans to use PMS for their preservation program, will also benefit from this research effort.
ContributorsN-Sang, Seng Hkawn (Author) / Kaloush, Kamil (Thesis advisor) / Medina, Jose (Committee member) / Mamlouk, Michael (Committee member) / Ozer, Hasan (Committee member) / Arizona State University (Publisher)
Created2022
Description
Thermal management of electronics is critical to meet the increasing demand for high power and performance. Thermal interface materials (TIMs) play a key role in dissipating heat away from the microelectronic chip and hence are a crucial component in electronics cooling. Challenges persist with overcoming the interfacial boundary resistance and filler particle connectivity in TIMs to achieve thermal percolation while maintaining mechanical compliance. Gallium-based liquid metal (LM) capsules offer a unique set of thermal-mechanical characteristics that make them suitable candidates for high-performance TIM fillers. This dissertation research focuses on resolving the fundamental challenges posed by integration of LM fillers in polymer matrix. First, the rupture mechanics of LM capsules under pressure is identified as a key factor that dictates the thermal connectivity between LM-based fillers. This mechanism of oxide “popping” in LM particle beds independent of the matrix material provides insights in overcoming the particle-particle connectivity challenges. Second, the physical barrier introduced due to the polymer matrix needs to be overcome to achieve thermal percolation. Matrix fluid viscosity impacts thermal transport, with high viscosity uncured matrix inhibiting the thermal bridging of fillers. In addition, incorporation of solid metal co-fillers that react with LM fillers is adopted to facilitate popping of LM oxide in uncured polymer to overcome this matrix barrier. Solid silver metal additives are used to rupture the LM oxide, form inter-metallic alloy (IMC), and act as thermal anchors within the matrix. This results in the formation of numerous thermal percolation paths and hence enhances heat transport within the composite. Further, preserving this microstructure of interconnected multiphase filler system with thermally conductive percolation pathways in a cured polymer matrix is critical to designing high-performing TIM pads. Viscosity of the precursor polymer solution prior to curing plays a major role in the resulting thermal conductivity. A multipronged strategy is developed that synergistically combines reactive solid and liquid fillers, a polymer matrix with low pre-cure viscosity, and mechanical compression during thermal curing. The results of this dissertation aim to provide fundamental insights into the integration of LMs in polymer composites and give design knobs to develop high thermally conducting soft composites.
ContributorsUppal, Aastha (Author) / Rykaczewski, Konrad (Thesis advisor) / Wang, Robert (Thesis advisor) / Kwon, Beomjin (Committee member) / Choksi, Gaurang (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2022
Description
Ministry of Transport (MOT) in the Kingdom of Saudi Arabia (KSA) is considering adopting the Mechanistic-Empirical Pavement Design method with its associated software the AASHTOWare Pavement ME Design (PMED) for its flexible pavements in the near future. The AASHTOWare PMED consists of distresses and international roughness index (IRI) prediction models that are nationally calibrated mainly using Long-Term Pavement Performance (LTPP) database in the United States. Implementing the AASHTOWare PMED in KSA requires two main tasks: 1. convert KSA data format to AASHTOWare PMED format, and 2. calibrate the distress and IRI models to KSA conditions. This study first prepared the KSA data to be accepted by AASHTOWare PMED and then calibrated the models to improve the pavement performance models predictions. After calibration, validation of these models was conducted to ensure accurate results with independent pavement sections. Goodness-of-fit statistics and null hypothesis test were used to assess each models’ prediction. Three flexible pavement models were successfully calibrated: asphalt concrete (AC) permanent deformation, top-down cracking, and IRI models. The results showed that the distress and IRI models with national (default) calibration are biased in predicating KSA pavements performance which required recalibration. Calibrating AC rutting, top-down cracking, and IRI models improved the prediction of KSA pavement performance. Most of the data used in this study were obtained from MOT. The AASHTOWare Pavement ME software (version 2.6.0) was used to complete the study.
ContributorsAlbuaymi, Mohammed Ibrahim (Author) / Kaloush, Kamil (Thesis advisor) / Mamlouk, Michael (Committee member) / Stempihar, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2021
Description新世纪以来中国电影的产业化改革与探索愈发呈现良好的态势，国产院线电影也在实践中努力赢得观众和票房市场。其中类型喜剧电影，最符合商业电影规律、最顺应影视市场需求、最能获得票房收益而备受影视创投机构、制作公司青睐。本论文研究对象聚焦类型喜剧电影，通过“欢声笑语里的财富”现象，探究类型喜剧电影内部本体构成要素与外部客观促成要素的关联；以通过分析自变量与因变量因素对中国电影票房之类型喜剧影响因素进行实证研究，为影视创投和影视制作总结并提供可靠建议。
本论文整体结构包括：第一部分为导论，包括研究背景、目的意义，相关文献综述与文献评述和论文创新性。第二部分聚焦类型喜剧本身，从电影学范畴的电影本体出发，探究“笑”的心理、社会与文化内涵，并分析将“笑”对经济领域的延伸。第三部分以影视投资、票房为依托，从现象和数据中探寻影响类型喜剧电影的因素，为展开中国电影票房之类型喜剧影响因素实证研究做好理论的铺垫。第四与第五部分则基于上述理论进行实证检验，选用2013-2020年电影样本，采用多元线性回归模型研究喜剧类型对票房的吸引力，以及不同种类型喜剧对电影票房的提振效果作用差异。研究发现喜剧电影对电影票房有显著的提振作用；以及研究电影的外部影响因素（续集效应）对电影票房的作用。发现续集电影有更好的票房表现，续集效应的票房提升作用在喜剧电影中表现的更加明显。
本论文研究成果最终将回归到“欢声笑语里的财富”本身；即“类型复合喜剧”对促进电影与金融产业的互动关联、实现更加可持续化发展，以及进而推动经济及文化业的发展。
ContributorsLiu, Yongqian (Author) / Shen, Wei (Thesis advisor) / Zhu, Ning (Thesis advisor) / Dong, Xiaodan (Committee member) / Arizona State University (Publisher)
Created2022