ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- Genre: Doctoral Dissertation
- Creators: Pei, Ker-Wei
Description
Concrete is the most widely used infrastructure material worldwide. Production of portland cement, the main binding component in concrete, has been shown to require significant energy and account for approximately 5-7% of global carbon dioxide production. The expected continued increased use of concrete over the coming decades indicates this is an ideal time to implement sustainable binder technologies. The current work aims to explore enhanced sustainability concretes, primarily in the context of limestone and flow. Aspects such as hydration kinetics, hydration product formation and pore structure add to the understanding of the strength development and potential durability characteristics of these binder systems. Two main strategies for enhancing this sustainability are explored in this work: (i) the use of high volume limestone in combination with other alternative cementitious materials to decrease the portland cement quantity in concrete and (ii) the use of geopolymers as the binder phase in concrete. The first phase of the work investigates the use of fine limestone as cement replacement from the perspective of hydration, strength development, and pore structure. The nature of the potential synergistic benefit of limestone and alumina will be explored. The second phase will focus on the rheological characterization of these materials in the fresh state, as well as a more general investigation of the rheological characterization of suspensions. The results of this work indicate several key ideas. (i) There is a potential synergistic benefit for strength, hydration, and pore structure by using alumina and in portland limestone cements, (ii) the limestone in these systems is shown to react to some extent, and fine limestone is shown to accelerate hydration, (iii) rheological characteristics of cementitious suspensions are complex, and strongly dependent on several key parameters including: the solid loading, interparticle forces, surface area of the particles present, particle size distribution of the particles, and rheological nature of the media in which the particles are suspended, and (iv) stress plateau method is proposed for the determination of rheological properties of concentrated suspensions, as it more accurately predicts apparent yield stress and is shown to correlate well with other viscoelastic properties of the suspensions.
ContributorsVance, Kirk (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Mobasher, Barzin (Committee member) / Chawla, Nikhilesh (Committee member) / Marzke, Robert (Committee member) / Arizona State University (Publisher)
Created2014
Description
Financing lease has bloomed as a new financing tool in China for the last several years. In this thesis I investigate the factors that influence China’s automobile financial leasing decisions by both lessors and lessees through market surveys. Based on Probit regression analysis of the data collected from 250 companies and 300 individuals, I find that a firm is more likely to use automobile financial leasing when its corporate tax rate is lower, growth potential is more stabilized, and profit is higher. It is also more likely to happen when a firm's long-term debt ratio and its degree of internationalization are higher. At the individual level, I find that the likelihood of individuals’ leasing decision is influenced by their risk preference, income level, and car price. Individuals’ gender, age and education level show no effect.
Using the analytic hierarchy process (AHP) analysis, I further find that financing costs, service value-added, and products diversity are the three most important competitive factors for the auto financial leasing service providers. This is the case for both the corporate and individual customers in the sample. By contrast, the factors of sales channel and government relationship are found to be much less important. Finally, through an in-depth case study of the leasing company Shanghai Auto Financial Leasing, I find that the key factors determining the customers’ credit default risk are interest rate and automobile type. I also investigate factors that influence business risk during the automobile procurement stage, at the selling stage, and toward the disposition stage. The managerial implications of the above results are discussed throughout the thesis.
Using the analytic hierarchy process (AHP) analysis, I further find that financing costs, service value-added, and products diversity are the three most important competitive factors for the auto financial leasing service providers. This is the case for both the corporate and individual customers in the sample. By contrast, the factors of sales channel and government relationship are found to be much less important. Finally, through an in-depth case study of the leasing company Shanghai Auto Financial Leasing, I find that the key factors determining the customers’ credit default risk are interest rate and automobile type. I also investigate factors that influence business risk during the automobile procurement stage, at the selling stage, and toward the disposition stage. The managerial implications of the above results are discussed throughout the thesis.
ContributorsLin, Zhen, Ph.D (Author) / Zhang, Anming (Thesis advisor) / Pei, Ker-Wei (Thesis advisor) / Chen, Hong (Committee member) / Arizona State University (Publisher)
Created2015
Description
In accordance with the Principal Agent Theory, Property Right Theory, Incentive Theory, and Human Capital Theory, firms face agency problems due to “separation of ownership and management”, which call for effective corporate governance. Ownership structure is a core element of the corporate governance. The differences in ownership structures thus may result in differential incentives in governance through the selection of senior management and in the design of senior management compensation system. This thesis investigates four firms with four different types of ownership structures: a public listed firm with the controlling interest by the state, a public listed firm with a non-state-owned controlling interest, a public listed firm a family-owned controlling interest, and a Sino-foreign joint venture firm. By using a case study approach, I focus on two dimensions of ownership structure characteristics – ownership diversification and differences in property rights so as to document whether there are systematic differences in governance participation and executive compensation design. Specifically, I focused on whether such differences are reflected in management selection (which is linked to adverse selection and moral hazard problems) and in compensation design (the choices of performance measurements, performance pay, and in stock option or restricted stock). The results are consistent with my expectation – the nature of ownership structure does affect senior management compensation design. Policy implications are discussed accordingly.
ContributorsGao, Shenghua (Author) / Pei, Ker-Wei (Thesis advisor) / Li, Feng (Committee member) / Shen, Wei (Committee member) / Arizona State University (Publisher)
Created2015
Description
Early-age cracks in fresh concrete occur mainly due to high rate of surface evaporation and restraint offered by the contracting solid phase. Available test methods that simulate severe drying conditions, however, were not originally designed to focus on evaporation and transport characteristics of the liquid-gas phases in a hydrating cementitious microstructure. Therefore, these tests lack accurate measurement of the drying rate and data interpretation based on the principles of transport properties is limited. A vacuum-based test method capable of simulating early-age cracks in 2-D cement paste is developed which continuously monitors the weight loss and changes to the surface characteristics. 2-D crack evolution is documented using time-lapse photography. Effects of sample size, w/c ratio, initial curing and fiber content are studied. In the subsequent analysis, the cement paste phase is considered as a porous medium and moisture transport is described based on surface mass transfer and internal moisture transport characteristics. Results indicate that drying occurs in two stages: constant drying rate period (stage I), followed by a falling drying rate period (stage II). Vapor diffusion in stage I and unsaturated flow within porous medium in stage II determine the overall rate of evaporation. The mass loss results are analyzed using diffusion-based models. Results show that moisture diffusivity in stage I is higher than its value in stage II by more than one order of magnitude. The drying model is used in conjunction with a shrinkage model to predict the development of capillary pressures. Similar approach is implemented in drying restrained ring specimens to predict 1-D crack width development. An analytical approach relates diffusion, shrinkage, creep, tensile and fracture properties to interpret the experimental data. Evaporation potential is introduced based on the boundary layer concept, mass transfer, and a driving force consisting of the concentration gradient. Effect of wind velocity is reflected on Reynolds number which affects the boundary layer on sample surface. This parameter along with Schmidt and Sherwood numbers are used for prediction of mass transfer coefficient. Concentration gradient is shown to be a strong function of temperature and relative humidity and used to predict the evaporation potential. Results of modeling efforts are compared with a variety of test results reported in the literature. Diffusivity data and results of 1-D and 2-D image analyses indicate significant effects of fibers on controlling early-age cracks. Presented models are capable of predicting evaporation rates and moisture flow through hydrating cement-based materials during early-age drying and shrinkage conditions.
ContributorsBakhshi, Mehdi (Author) / Mobasher, Barzin (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Zapata, Claudia E. (Committee member) / Arizona State University (Publisher)
Created2011
Description
With the increasing focus on developing environmentally benign electronic packages, lead-free solder alloys have received a great deal of attention. Mishandling of packages, during manufacture, assembly, or by the user may cause failure of solder joint. A fundamental understanding of the behavior of lead-free solders under mechanical shock conditions is lacking. Reliable experimental and numerical analysis of lead-free solder joints in the intermediate strain rate regime need to be investigated. This dissertation mainly focuses on exploring the mechanical shock behavior of lead-free tin-rich solder alloys via multiscale modeling and numerical simulations. First, the macroscopic stress/strain behaviors of three bulk lead-free tin-rich solders were tested over a range of strain rates from 0.001/s to 30/s. Finite element analysis was conducted to determine appropriate specimen geometry that could reach a homogeneous stress/strain field and a relatively high strain rate. A novel self-consistent true stress correction method is developed to compensate the inaccuracy caused by the triaxial stress state at the post-necking stage. Then the material property of micron-scale intermetallic was examined by micro-compression test. The accuracy of this measure is systematically validated by finite element analysis, and empirical adjustments are provided. Moreover, the interfacial property of the solder/intermetallic interface is investigated, and a continuum traction-separation law of this interface is developed from an atomistic-based cohesive element method. The macroscopic stress/strain relation and microstructural properties are combined together to form a multiscale material behavior via a stochastic approach for both solder and intermetallic. As a result, solder is modeled by porous plasticity with random voids, and intermetallic is characterized as brittle material with random vulnerable region. Thereafter, the porous plasticity fracture of the solders and the brittle fracture of the intermetallics are coupled together in one finite element model. Finally, this study yields a multiscale model to understand and predict the mechanical shock behavior of lead-free tin-rich solder joints. Different fracture patterns are observed for various strain rates and/or intermetallic thicknesses. The predictions have a good agreement with the theory and experiments.
ContributorsFei, Huiyang (Author) / Jiang, Hanqing (Thesis advisor) / Chawla, Nikhilesh (Thesis advisor) / Tasooji, Amaneh (Committee member) / Mobasher, Barzin (Committee member) / Rajan, Subramaniam D. (Committee member) / Arizona State University (Publisher)
Created2011
Description
Increased priority on the minimization of environmental impacts of conventional construction materials in recent years has motivated increased use of waste materials or bi-products such as fly ash, blast furnace slag with a view to reduce or eliminate the manufacturing/consumption of ordinary portland cement (OPC) which accounts for approximately 5-7% of global carbon dioxide emission. The current study explores, for the first time, the possibility of carbonating waste metallic iron powder to develop carbon-negative sustainable binder systems for concrete. The fundamental premise of this work is that metallic iron will react with aqueous CO2 under controlled conditions to form complex iron carbonates which have binding capabilities. The compressive and flexural strengths of the chosen iron-based binder systems increase with carbonation duration and the specimens carbonated for 4 days exhibit mechanical properties that are comparable to those of companion ordinary portland cement systems. The optimal mixture proportion and carbonation regime for this non-conventional sustainable binder is established based on the study of carbonation efficiency of a series of mixtures using thermogravimetric analysis. The pore- and micro-structural features of this novel binding material are also evaluated. The fracture response of this novel binder is evaluated using strain energy release rate and measurement of fracture process zone using digital image correlation (DIC). The iron-based binder system exhibits significantly higher strain energy release rates when compared to those of the OPC systems in both the unreinforced and glass fiber reinforced states. The iron-based binder also exhibits higher amount of area of fracture process zone due to its ability to undergo inelastic deformation facilitated by unreacted metallic iron particle inclusions in the microstructure that helps crack bridging /deflection. The intrinsic nano-mechanical properties of carbonate reaction product are explored using statistical nanoindentation technique coupled with a stochastic deconvolution algorithm. Effect of exposure to high temperature (up to 800°C) is also studied. Iron-based binder shows significantly higher residual flexural strength after exposure to high temperatures. Results of this comprehensive study establish the viability of this binder type for concrete as an environment-friendly and economical alternative to OPC.
ContributorsDas, Sumanta (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, S.D. (Committee member) / Mobasher, Barzin (Committee member) / Marzke, Robert (Committee member) / Chawla, Nikhilesh (Committee member) / Stone, David (Committee member) / Arizona State University (Publisher)
Created2015
Description
Health is among the most basic needs of the people and driving force of social and economic development. The health nutrition & wellness industry is gradually becoming a global sunrise industry . However, the industry is faced many problems and challenges including weaknesses in the industry structure, fragmentations of supply chain, low
efficiency in resources allocation, and lacking in quality on personnel training. To achieve core competitiveness and value creation, it is important that the health nutrition & wellness industry must meet the needs of Chinese market and its customers with a customer centric perspective to design a firm’s organization strucrture and management processes. This thesis is based on an analysis of the competitive landscape faced by the nutrition & wellness industry as exemplified by By-Health.Ltd. The investigation begins with an analysis and synthsis of the common industry practices on sales & distribution channels for their underlying similarities and differences in product strategies, branding strategies, and agency models on incentive design and profit sharing mechanisms. Through an empirical survey, this thesis also investigate customer’s demand for nutritious and healthy products. The results through factor analysis reveal that such demands are driven by individual factor, product factor, enterprise factor and environmental factor. The study concludes with a proposed framework to link customer value through three innovative designs in sales and distribution: community marketing model, sharing marketing model and Internet factory marketing model.
efficiency in resources allocation, and lacking in quality on personnel training. To achieve core competitiveness and value creation, it is important that the health nutrition & wellness industry must meet the needs of Chinese market and its customers with a customer centric perspective to design a firm’s organization strucrture and management processes. This thesis is based on an analysis of the competitive landscape faced by the nutrition & wellness industry as exemplified by By-Health.Ltd. The investigation begins with an analysis and synthsis of the common industry practices on sales & distribution channels for their underlying similarities and differences in product strategies, branding strategies, and agency models on incentive design and profit sharing mechanisms. Through an empirical survey, this thesis also investigate customer’s demand for nutritious and healthy products. The results through factor analysis reveal that such demands are driven by individual factor, product factor, enterprise factor and environmental factor. The study concludes with a proposed framework to link customer value through three innovative designs in sales and distribution: community marketing model, sharing marketing model and Internet factory marketing model.
ContributorsGong, Binghui (Author) / Pei, Ker-Wei (Thesis advisor) / Cui, Haitao (Thesis advisor) / Gu, Bin (Committee member) / Arizona State University (Publisher)
Created2018
Description随着社会经济发展，人们生活水平提高，红木市场不断发展壮大。但红木市场中存在
原材料无法认证、加工工艺无法辨别、产品价格混乱的现象，成为我国红木市场三大痛
点。能否解决红木市场这三大痛点，成为未来红木行业能否健康顺利发展的关键因素。
针对红木行业存在的问题，本文应用市场交易效率理论、信息不对称理论、金融市场
微观结构理论对红木市场做理论梳理，通过实地调研获取红木企业发展现状、厘清传统红
木交易流程和各交易环节中存在的问题，尝试在信息不对称理论的框架下对行业和典型企
业进行分析，将红木市场的交易要素进行序列梳理，重构市场组织和流程再造，创造性地
利用现代的互联网技术，把涉及的非标准的市场要素进行标准化设计，使其成为可交易的
标准化标的产品，并在设计可操作性的红木交易平台上进行交易，从而解决现有红木市场
中信息不对称导致的市场交易效率低下问题。本文一共分为十一章，第一到第五章为绪论、理论研究和研究综述。主要根据市场交
易效率理论、信息不对称理论和金融市场微观结构理论，引出建立红木交易市场，从而为
后续红木交易市场的设计奠定理论基础。第五章，对红木产业及其市场的要素进行信息解
析，为后面的非标准的市场要素进行标准化设计提供依据。第六、第七章，主要对红木交
易市场的信息不对称现状、红木交易市场交易效率进行分析。第八、第九章，主要基于信
息对称条件下的交易要素标准化设计和交易架构设计。第十章，主要通过对实际数据抓
取，对红木交易平台的有效性进行实证对比验证。第十一章是本文的结论和建议。
由于红木交易平台的设计是弥补大宗交易的空白，特别是红木交易市场要素的非标
准化，给标准化交易架构的设计带来一定难度。红木交易平台未来运营与发展中可能会遇
到很多风险，特别是投资者资格认证、交易涉众等社会问题，本文限于篇幅没有进行研
究，留待今后实践中不断总结和修正。
原材料无法认证、加工工艺无法辨别、产品价格混乱的现象，成为我国红木市场三大痛
点。能否解决红木市场这三大痛点，成为未来红木行业能否健康顺利发展的关键因素。
针对红木行业存在的问题，本文应用市场交易效率理论、信息不对称理论、金融市场
微观结构理论对红木市场做理论梳理，通过实地调研获取红木企业发展现状、厘清传统红
木交易流程和各交易环节中存在的问题，尝试在信息不对称理论的框架下对行业和典型企
业进行分析，将红木市场的交易要素进行序列梳理，重构市场组织和流程再造，创造性地
利用现代的互联网技术，把涉及的非标准的市场要素进行标准化设计，使其成为可交易的
标准化标的产品，并在设计可操作性的红木交易平台上进行交易，从而解决现有红木市场
中信息不对称导致的市场交易效率低下问题。本文一共分为十一章，第一到第五章为绪论、理论研究和研究综述。主要根据市场交
易效率理论、信息不对称理论和金融市场微观结构理论，引出建立红木交易市场，从而为
后续红木交易市场的设计奠定理论基础。第五章，对红木产业及其市场的要素进行信息解
析，为后面的非标准的市场要素进行标准化设计提供依据。第六、第七章，主要对红木交
易市场的信息不对称现状、红木交易市场交易效率进行分析。第八、第九章，主要基于信
息对称条件下的交易要素标准化设计和交易架构设计。第十章，主要通过对实际数据抓
取，对红木交易平台的有效性进行实证对比验证。第十一章是本文的结论和建议。
由于红木交易平台的设计是弥补大宗交易的空白，特别是红木交易市场要素的非标
准化，给标准化交易架构的设计带来一定难度。红木交易平台未来运营与发展中可能会遇
到很多风险，特别是投资者资格认证、交易涉众等社会问题，本文限于篇幅没有进行研
究，留待今后实践中不断总结和修正。
ContributorsChiu, Yung (Author) / Pei, Ker-Wei (Thesis advisor) / Qian, Jun (Thesis advisor) / Wu, Fei (Committee member) / Arizona State University (Publisher)
Created2018
Description
Being a remarkably versatile and inexpensive building material, concrete has found tremendous use in development of modern infrastructure and is the most widely used material in the world. Extensive research in the field of concrete has led to the development of a wide array of concretes with applications ranging from building of skyscrapers to paving of highways. These varied applications require special cementitious composites which can satisfy the demand for enhanced functionalities such as high strength, high durability and improved thermal characteristics among others.
The current study focuses on the fundamental understanding of such functional composites, from their microstructural design to macro-scale application. More specifically, this study investigates three different categories of functional cementitious composites. First, it discusses the differences between cementitious systems containing interground and blended limestone with and without alumina. The interground systems are found to outperform the blended systems due to differential grinding of limestone. A novel approach to deduce the particle size distribution of limestone and cement in the interground systems is proposed. Secondly, the study delves into the realm of ultra-high performance concrete, a novel material which possesses extremely high compressive-, tensile- and flexural-strength and service life as compared to regular concrete. The study presents a novel first principles-based paradigm to design economical ultra-high performance concretes using locally available materials. In the final part, the study addresses the thermal benefits of a novel type of concrete containing phase change materials. A software package was designed to perform numerical simulations to analyze temperature profiles and thermal stresses in concrete structures containing PCMs.
The design of these materials is accompanied by material characterization of cementitious binders. This has been accomplished using techniques that involve measurement of heat evolution (isothermal calorimetry), determination and quantification of reaction products (thermo-gravimetric analysis, x-ray diffraction, micro-indentation, scanning electron microscopy, energy-dispersive x-ray spectroscopy) and evaluation of pore-size distribution (mercury intrusion porosimetry). In addition, macro-scale testing has been carried out to determine compression, flexure and durability response. Numerical simulations have been carried out to understand hydration of cementitious composites, determine optimum particle packing and determine the thermal performance of these composites.
The current study focuses on the fundamental understanding of such functional composites, from their microstructural design to macro-scale application. More specifically, this study investigates three different categories of functional cementitious composites. First, it discusses the differences between cementitious systems containing interground and blended limestone with and without alumina. The interground systems are found to outperform the blended systems due to differential grinding of limestone. A novel approach to deduce the particle size distribution of limestone and cement in the interground systems is proposed. Secondly, the study delves into the realm of ultra-high performance concrete, a novel material which possesses extremely high compressive-, tensile- and flexural-strength and service life as compared to regular concrete. The study presents a novel first principles-based paradigm to design economical ultra-high performance concretes using locally available materials. In the final part, the study addresses the thermal benefits of a novel type of concrete containing phase change materials. A software package was designed to perform numerical simulations to analyze temperature profiles and thermal stresses in concrete structures containing PCMs.
The design of these materials is accompanied by material characterization of cementitious binders. This has been accomplished using techniques that involve measurement of heat evolution (isothermal calorimetry), determination and quantification of reaction products (thermo-gravimetric analysis, x-ray diffraction, micro-indentation, scanning electron microscopy, energy-dispersive x-ray spectroscopy) and evaluation of pore-size distribution (mercury intrusion porosimetry). In addition, macro-scale testing has been carried out to determine compression, flexure and durability response. Numerical simulations have been carried out to understand hydration of cementitious composites, determine optimum particle packing and determine the thermal performance of these composites.
ContributorsArora, Aashay (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Mobasher, Barzin (Committee member) / Chawla, Nikhilesh (Committee member) / Hoover, Christian G (Committee member) / Arizona State University (Publisher)
Created2018
Description
Phase change materials (PCMs) are combined sensible-and-latent thermal energy storage materials that can be used to store and dissipate energy in the form of heat. PCMs incorporated into wall-element systems have been well-studied with respect to energy efficiency of building envelopes. New applications of PCMs in infrastructural concrete, e.g., for mitigating early-age cracking and freeze-and-thaw induced damage, have also been proposed. Hence, the focus of this dissertation is to develop a detailed understanding of the physic-chemical and thermo-mechanical characteristics of cementitious systems and novel coating systems for wall-elements containing PCM. The initial phase of this work assesses the influence of interface properties and inter-inclusion interactions between microencapsulated PCM, macroencapsulated PCM, and the cementitious matrix. The fact that these inclusions within the composites are by themselves heterogeneous, and contain multiple components necessitate careful application of models to predict the thermal properties. The next phase observes the influence of PCM inclusions on the fracture and fatigue behavior of PCM-cementitious composites. The compliant nature of the inclusion creates less variability in the fatigue life for these composites subjected to cyclic loading. The incorporation of small amounts of PCM is found to slightly improve the fracture properties compared to PCM free cementitious composites. Inelastic deformations at the crack-tip in the direction of crack opening are influenced by the microscale PCM inclusions. After initial laboratory characterization of the microstructure and evaluation of the thermo-mechanical performance of these systems, field scale applicability and performance were evaluated. Wireless temperature and strain sensors for smart monitoring were embedded within a conventional portland cement concrete pavement (PCCP) and a thermal control smart concrete pavement (TCSCP) containing PCM. The TCSCP exhibited enhanced thermal performance over multiple heating and cooling cycles. PCCP showed significant shrinkage behavior as a result of compressive strains in the reinforcement that were twice that of the TCSCP. For building applications, novel PCM-composites coatings were developed to improve and extend the thermal efficiency. These coatings demonstrated a delay in temperature by up to four hours and were found to be more cost-effective than traditional building insulating materials.
The results of this work prove the feasibility of PCMs as a temperature-regulating technology. Not only do PCMs reduce and control the temperature within cementitious systems without affecting the rate of early property development but they can also be used as an auto-adaptive technology capable of improving the thermal performance of building envelopes.
The results of this work prove the feasibility of PCMs as a temperature-regulating technology. Not only do PCMs reduce and control the temperature within cementitious systems without affecting the rate of early property development but they can also be used as an auto-adaptive technology capable of improving the thermal performance of building envelopes.
ContributorsAguayo, Matthew Joseph (Author) / Neithalath, Narayanan (Thesis advisor) / Rajan, Subramaniam D. (Committee member) / Mobasher, Barzin (Committee member) / Underwood, Benjamin (Committee member) / Liu, Yongming (Committee member) / Arizona State University (Publisher)
Created2018