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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- Creators: Shen, Wei
- Creators: Kavazanjian, Edward
Description
Informal finance in this paper refers to the financing activities of individuals or households to borrow money through channels other than formal financial institutions such as commercial banks. Using data from China Household Finance Survey (CHFS) conducted by Southwestern University of Finance and Economics (SWUFE) and the People's Bank of China, this paper employs Probit model to analyze the factors that may influence the financing needs of Chinese households and factors that influence their likelihood of obtaining loans from formal financial institutions versus from informal channels. Results show that household wealth, family structure, and household head’s characteristics are the major factors that influence their financing needs. Moreover, the results suggest that (a) richer families are more likely to obtain loans from formal financial channels while poorer families are more likely to do so from informal channels; (b) families with stronger social ties are more likely to obtain loans from formal financial channels, but this relationship is weaker in regions where the financial market is more competitive;and (c) the increase of formal financial services is positively related to the probability of households obtaining formal finance, but has no relationship with the probability of households obtaining informal finance. These findings have important implications for finance policy making.
ContributorsZhang, Linchao (Author) / Shen, Wei (Thesis advisor) / Chen, Xiaoping (Thesis advisor) / Liu, Jun (Committee member) / Arizona State University (Publisher)
Created2016
Description
The dissimilatory reduction of nitrate, or denitrification, offers the potential of a sustainable, cost effective method for the non-disruptive mitigation of earthquake-induced soil liquefaction. Worldwide, trillions of dollars of infrastructure are at risk for liquefaction damage in earthquake prone regions. However, most techniques for remediating liquefiable soils are either not applicable to sites near existing infrastructure, or are prohibitively expensive. Recently, laboratory studies have shown the potential for biogeotechnical soil improvement techniques such as microbially induced carbonate precipitation (MICP) to mitigate liquefaction potential in a non-disruptive manner. Multiple microbial processes have been identified for MICP, but only two have been extensively studied. Ureolysis, the most commonly studied process for MICP, has been shown to quickly and efficiently induce carbonate precipitation on particle surfaces and at particle contacts to improve the stiffness, strength, and dilatant behavior of liquefiable soils. However, ureolysis also produces copious amounts of ammonium, a potentially toxic byproduct. The second process studied for MICP, denitrification, has been shown to precipitate carbonate, and hence improve soil properties, much more slowly than ureolysis. However, the byproducts of denitrification, nitrogen and carbon dioxide gas, are non-toxic, and present the added benefit of rapidly desaturating the treated soil. Small amounts of desaturation have been shown to increase the cyclic resistance, and hence the liquefaction resistance, of liquefiable soils. So, denitrification offers the potential to mitigate liquefaction as a two-stage process, with desaturation providing short term mitigation, and MICP providing long term liquefaction resistance. This study presents the results of soil testing, stoichiometric modeling, and microbial ecology characterization to better characterize the potential use of denitrification as a two-stage process for liquefaction mitigation.
ContributorsO'Donnell, Sean (Author) / Kavazanjian, Edward (Thesis advisor) / Rittmann, Bruce (Committee member) / Houston, Sandra (Committee member) / Arizona State University (Publisher)
Created2016
Description
This thesis investigates whether mergers and acquisitions (M&As) help increase the competitive advantage and core competency of Chinese securities companies. Although M&As among Chinese securities companies were almost exclusively guided by the Chinese government in the earlier years, they have increasingly become more market-driven in recent years. Many large Chinese securities companies have engaged in horizontal mergers, cross-industry mergers, and cross-border mergers to increase their market positions. However, there is little up-to-date evidence about how these market-driven M&As influence the competitive advantage and core competency of securities companies in China. I seek to fill this gap by conducting a systematic analysis about whether M&As increase the core competency of the acquiring companies using data collected over a five-year window from 2010 to 2014.
On the basis of prior research findings and the current situation of the Chinese securities industry, I first develop a theoretical model about the sources of competitive advantage for Chinese securities companies, and then compile a comprehensive list of observable indicators that can be used to assess a Chinese securities company’s core competency. Next, I conduct a quantitative analysis to assess the core competency and relative market positions of the leading Chinese securities companies using data from 2010 to 2014. Overall, the results suggest that market-driven M&As increases the core competency of the acquiring securities companies. I then conduct four in-depth case analyses to better understand the mechanisms through which M&As can help increase the acquiring firms' core competency. I conclude with a discussion of the findings and their implications for Chinese securities companies and the overseeing governmental agencies.
On the basis of prior research findings and the current situation of the Chinese securities industry, I first develop a theoretical model about the sources of competitive advantage for Chinese securities companies, and then compile a comprehensive list of observable indicators that can be used to assess a Chinese securities company’s core competency. Next, I conduct a quantitative analysis to assess the core competency and relative market positions of the leading Chinese securities companies using data from 2010 to 2014. Overall, the results suggest that market-driven M&As increases the core competency of the acquiring securities companies. I then conduct four in-depth case analyses to better understand the mechanisms through which M&As can help increase the acquiring firms' core competency. I conclude with a discussion of the findings and their implications for Chinese securities companies and the overseeing governmental agencies.
ContributorsWang, Lijuan (Author) / Shen, Wei (Thesis advisor) / Qian, Jun (Thesis advisor) / Liu, Jun (Committee member) / Arizona State University (Publisher)
Created2016
Description
The understanding of multiphase fluid flow in porous media is of great importance in many fields such as enhanced oil recovery, hydrology, CO2 sequestration, contaminants cleanup, and natural gas production from hydrate bearing sediments.
In this study, first, the water retention curve (WRC) and relative permeability in hydrate bearing sediments are explored to obtain fitting parameters for semi-empirical equations. Second, immiscible fluid invasion into porous media is investigated to identify fluid displacement pattern and displacement efficiency that are affected by pore size distribution and connectivity. Finally, fluid flow through granular media is studied to obtain fluid-particle interaction. This study utilizes the combined techniques of discrete element method simulation, micro-focus X-ray computed tomography (CT), pore-network model simulation algorithms for gas invasion, gas expansion, and relative permeability calculation, transparent micromodels, and water retention curve measurement equipment modified for hydrate-bearing sediments. In addition, a photoelastic disk set-up is fabricated and the image processing technique to correlate the force chain to the applied contact forces is developed.
The results show that the gas entry pressure and the capillary pressure increase with increasing hydrate saturation. Fitting parameters are suggested for different hydrate saturation conditions and morphologies. And, a new model for immiscible fluid invasion and displacement is suggested in which the boundaries of displacement patterns depend on the pore size distribution and connectivity. Finally, the fluid-particle interaction study shows that the fluid flow increases the contact forces between photoelastic disks in parallel direction with the fluid flow.
In this study, first, the water retention curve (WRC) and relative permeability in hydrate bearing sediments are explored to obtain fitting parameters for semi-empirical equations. Second, immiscible fluid invasion into porous media is investigated to identify fluid displacement pattern and displacement efficiency that are affected by pore size distribution and connectivity. Finally, fluid flow through granular media is studied to obtain fluid-particle interaction. This study utilizes the combined techniques of discrete element method simulation, micro-focus X-ray computed tomography (CT), pore-network model simulation algorithms for gas invasion, gas expansion, and relative permeability calculation, transparent micromodels, and water retention curve measurement equipment modified for hydrate-bearing sediments. In addition, a photoelastic disk set-up is fabricated and the image processing technique to correlate the force chain to the applied contact forces is developed.
The results show that the gas entry pressure and the capillary pressure increase with increasing hydrate saturation. Fitting parameters are suggested for different hydrate saturation conditions and morphologies. And, a new model for immiscible fluid invasion and displacement is suggested in which the boundaries of displacement patterns depend on the pore size distribution and connectivity. Finally, the fluid-particle interaction study shows that the fluid flow increases the contact forces between photoelastic disks in parallel direction with the fluid flow.
ContributorsMahabadi, Nariman (Author) / Jang, Jaewon (Thesis advisor) / Zapata, Claudia (Committee member) / Kavazanjian, Edward (Committee member) / Arizona State University (Publisher)
Created2016
Description
Nanotechnology has been applied to many areas such as medicine, manufacturing, catalysis, food, cosmetics, and energy since the beginning 21st century. However, the application of nanotechnology to geotechnical engineering has not received much attention. This research explored the technical benefits and the feasibility of applying nanoparticles in geotechnical engineering. Specific studies were conducted by utilizing high-pressure devices, axisymmetric drop shape analysis (ADSA), microfluidics, time-lapse technology, Atomic Force Microscopy (AFM) to develop experiments. The effects of nanoparticle on modifying interfacial tension, wettability, viscosity, sweep efficiency and surface attraction forces were investigated. The results show that nanoparticles mixed in water can significantly reduce the interfacial tension of water in CO2 in the applications of nanofluid-CO2 flow in sediments; nanoparticle stabilized foam can be applied to isolate contaminants from clean soils in groundwater/soil remediation, as well as in CO2 geological sequestration or enhanced oil/gas recovery to dramatically improve the sweep efficiency; nanoparticle coatings are capable to increase the surface adhesion force so as to capture migrating fine particles to help prevent clogging near wellbore or in granular filter in the applications of oil and gas recovery, geological CO2 sequestration, geothermal recovery, contaminant transport, groundwater flow, and stormwater management system.
ContributorsZheng, Xianglei (Author) / Jang, Jaewon (Thesis advisor) / Zapata, Claudia (Committee member) / Kavazanjian, Edward (Committee member) / Arizona State University (Publisher)
Created2016
Description
A series of experiments were conducted to support validation of a numerical model for the performance of geomembrane liners subject to waste settlement and seismic loading. These experiments included large scale centrifuge model testing of a geomembrane-lined landfill, small scale laboratory testing to get the relevant properties of the materials used in the large scale centrifuge model, and tensile tests on seamed geomembrane coupons. The landfill model in the large scale centrifuge test was built with a cemented sand base, a thin film NafionTM geomembrane liner, and a mixture of sand and peat for model waste. The centrifuge model was spun up to 60 g, allowed to settle, and then subjected to seismic loading at three different peak ground accelerations (PGA). Strain on the liner and settlement of the waste during model spin-up and subsequent seismic loading and accelerations throughout the model due to seismic loading were acquired from sensors within the model. Laboratory testing conducted to evaluate the properties of the materials used in the model included triaxial compression tests on the cemented sand base, wide-width tensile testing of the thin film geomembrane, interface shear testing between the thin film geomembrane and the waste material, and one dimensional compression and cyclic direct simple shear testing of the sand-peat mixture used to simulate the waste. The tensile tests on seamed high-density polyethylene (HDPE) coupons were conducted to evaluate strain concentration associated with seams oriented perpendicular to an applied tensile load. Digital image correlation (DIC) was employed to evaluate the strain field, and hence seam strain concentrations, in these tensile tests. One-dimensional compression tests were also conducted on composite sand and HDPE samples to evaluate the compressive modulus of HDPE. The large scale centrifuge model and small scale laboratory tests provide the necessary data for numerical model validation. The tensile tests on seamed HDPE specimens show that maximum tensile strain due to strain concentrations at a seam is greater than previously suggested, a finding with profound implications for landfill liner design and construction quality control/quality assurance (QC/QA) practices. The results of the one-dimensional compression tests on composite sand-HDPE specimens were inconclusive.
ContributorsGutierrez, Angel (Author) / Kavazanjian, Edward (Thesis advisor) / Zapata, Claudia (Committee member) / Jang, Jaewon (Committee member) / Arizona State University (Publisher)
Created2016
Description
University graduates play a significant role in the labor market of China. Universities continuously supply senior talents and provide a strong guarantee to the country’s development. However, with the enlargement of the enrollment scale, more and more graduates become unemployed or forced to be employed. Most literatures mainly focus on the unemployed phenomenon or reasons, but had neglected the relationship among the employment, universities and the labor market. This assay is trying to using the supply and demand theory of classical economics to analyze the training direction and model of university from the perspective of the supply and demand of labor market. This assay proposes that universities have to integrate with the demand of the labor market so that to cultivate the talents to meet the social needs.
Firstly, the essay analyzes the relationship between the universities education and the supply and demand labor market by using the view of labor economics, and shows the mainly phenomenon and features of supply-demand imbalance. And then, the writer considered that universities talent cultivation development of China has gone through “absolute shortage”, “relative shortage” and “structural unbalanced” three stages. Thirdly, the survey results confirmed that the talent cultivation in universities does not match the demand of the labor market. On one other hand, over educated is a common phenomenon in the academic education. On the other hand, the graduates are lack of education skills training. Fourthly, the essay analyzes the reasons which lead to the unbalance. The unbalance is not only affected by the macro factors, but also by the micro factors. Fifthly, build up the interaction system model “UPT-LM” for the universities talent cultivation and the labor market, and separately building up the macro interaction system and the micro interaction system to analyze the balance of supply and demand. Based on this, it should strengthen the interaction on the feedback mechanism. At last, strengthening the connection of universities talent cultivation and labor market is a systematic program which needs the corporation from the government, the universities and the labor market.
Firstly, the essay analyzes the relationship between the universities education and the supply and demand labor market by using the view of labor economics, and shows the mainly phenomenon and features of supply-demand imbalance. And then, the writer considered that universities talent cultivation development of China has gone through “absolute shortage”, “relative shortage” and “structural unbalanced” three stages. Thirdly, the survey results confirmed that the talent cultivation in universities does not match the demand of the labor market. On one other hand, over educated is a common phenomenon in the academic education. On the other hand, the graduates are lack of education skills training. Fourthly, the essay analyzes the reasons which lead to the unbalance. The unbalance is not only affected by the macro factors, but also by the micro factors. Fifthly, build up the interaction system model “UPT-LM” for the universities talent cultivation and the labor market, and separately building up the macro interaction system and the micro interaction system to analyze the balance of supply and demand. Based on this, it should strengthen the interaction on the feedback mechanism. At last, strengthening the connection of universities talent cultivation and labor market is a systematic program which needs the corporation from the government, the universities and the labor market.
ContributorsLin, Xiaoya (Author) / Shen, Wei (Thesis advisor) / Qian, Jun (Thesis advisor) / Li, Feng (Committee member) / Arizona State University (Publisher)
Created2017
Description
This dissertation presents an investigation of calcium carbonate precipitation via hydrolysis of urea (ureolysis) catalyzed by plant-extracted urease enzyme for soil improvement. In this approach to soil improvement, referred to as enzyme induced carbonate precipitation (EICP), carbonate minerals are precipitated within the soil pores, cementing soil particles together and increasing the dilatancy of the soil. EICP is a bio-inspired solution to improving the properties of cohesionless soil in that no living organisms are engaged in the process, though it uses a biologically-derived material (urease enzyme).
Over the past decade, research has commenced on biologically-mediated solutions like microbially induced carbonate precipitation (MICP) and biologically-inspired solutions like EICP for non-disruptive ground improvement. Both of these approaches rely upon hydrolysis of urea catalyzed by the enzyme urease. Under the right environmental conditions (e.g., pH), the hydrolysis of urea leads to calcium carbonate precipitation in the presence of Ca^(2+). The rate of carbonate precipitation via hydrolysis of urea can be up to 〖10〗^14 times faster than natural process.
The objective of this research was to ascertain the effectiveness of EICP for soil improvement via hydrolysis of urea (ureolysis) catalyzed by plant-extracted urease enzyme. Elements of this work include: 1) systematic experiments to identify an optimum EICP treatment solution; 2) evaluation of the mechanical properties of EICP-treated soil under different treatment conditions and with varying carbonate contents; 3) investigation of the potential for enhancing the EICP stabilization process by including xanthan gum, natural sisal fiber, and powdered of dried non-fat milk in the EICP treatment solution; and 4) bench-scale studies of the use of EICP to make sub-horizontal columns of cemented soil for soil nailing and vertical columns of cemented soil for foundation support. As part of this research, the effect of three preparation methods (mix-and-compact, percolation, and injection) was also examined as was the influence of the grain size of soil. The results of this study should help make the EICP technique an attractive option for geotechnical engineers for ground improvement and stimulate the development and use of other biogeotechnical techniques for civil engineering purposes.
Over the past decade, research has commenced on biologically-mediated solutions like microbially induced carbonate precipitation (MICP) and biologically-inspired solutions like EICP for non-disruptive ground improvement. Both of these approaches rely upon hydrolysis of urea catalyzed by the enzyme urease. Under the right environmental conditions (e.g., pH), the hydrolysis of urea leads to calcium carbonate precipitation in the presence of Ca^(2+). The rate of carbonate precipitation via hydrolysis of urea can be up to 〖10〗^14 times faster than natural process.
The objective of this research was to ascertain the effectiveness of EICP for soil improvement via hydrolysis of urea (ureolysis) catalyzed by plant-extracted urease enzyme. Elements of this work include: 1) systematic experiments to identify an optimum EICP treatment solution; 2) evaluation of the mechanical properties of EICP-treated soil under different treatment conditions and with varying carbonate contents; 3) investigation of the potential for enhancing the EICP stabilization process by including xanthan gum, natural sisal fiber, and powdered of dried non-fat milk in the EICP treatment solution; and 4) bench-scale studies of the use of EICP to make sub-horizontal columns of cemented soil for soil nailing and vertical columns of cemented soil for foundation support. As part of this research, the effect of three preparation methods (mix-and-compact, percolation, and injection) was also examined as was the influence of the grain size of soil. The results of this study should help make the EICP technique an attractive option for geotechnical engineers for ground improvement and stimulate the development and use of other biogeotechnical techniques for civil engineering purposes.
ContributorsAlmajed, Abdullah A. (Author) / Kavazanjian, Edward (Thesis advisor) / Zapata, Claudia (Committee member) / Hamdan, Nasser M (Committee member) / Arizona State University (Publisher)
Created2017
Description
Recent research efforts have been directed to improve the quality of pavement design procedures by considering the transient nature of soil properties due to environmental and aging effects on pavement performance. The main purpose of this research study was to investigate the existence of subgrade soil moisture changes that may have arisen due to thermal and hydraulic gradients at the Atlantic City NAPTF and to evaluate their effect on the material stiffness and the California Bearing Ratio (CBR) strength parameter of the clay subgrade materials. Laboratory data showed that at the same water content, matric suction decreases with increasing temperature; and at the same suction, hydraulic conductivity increases with increasing temperature. Models developed, together with moisture/temperature data collected from 30 sensors installed in the test facility, yielded a maximum variation of suction in field of 155 psi and changes in hydraulic conductivity from 2.9E-9 m/s at 100% saturation to 8.1E-12 at 93% saturation. The maximum variation in temperature was found to be 20.8oC at the shallower depth and decreased with depth; while a maximum variation in moisture content was found to be 3.7% for Dupont clay and 4.4% for County clay. Models developed that predicts CBR as a function of dry density and moisture content yielded a maximum variation of CBR of 2.4 for Dupont clay and 2.9 for County clay. Additionally, models were developed relating the temperature with the bulk stress and octahedral stress applied on the subgrade for dual gear, dual tandem and triple tandem gear types for different tire loads. It was found that as the temperature increases the stresses increase. A Modified Cary and Zapata model was used for predicting the resilient modulus(Mr) of the subgrade. Using the models developed and the temperature/moisture changes observed in the field, the variation of suction, bulk and octahedral stresses were estimated, along with the resilient modulus for three different gear types. Results indicated that changes in Mr as large as 9 ksi occur in the soils studied due to the combined effect of external loads and environmental condition changes.
ContributorsThirthar Palanivelu, Pugazhvel (Author) / Zapata, Claudia E (Thesis advisor) / Kavazanjian, Edward (Committee member) / Houston, Sandra (Committee member) / Underwood, Shane (Committee member) / Arizona State University (Publisher)
Created2017
Description
A numerical model for design of the geomembrane elements of waste containment systems has been validated by laboratory testing. Due to the absence of any instrumented case histories of seismic performance of geomembrane liner systems, a large scale centrifuge test of a model geomembrane-lined landfill subject to seismic loading was conducted at the University of California at Davis Centrifuge Test facility as part of National Science Foundation Network for Earthquake the Engineering Simulation Research (NEESR) program. Data collected in the large scale centrifuge test included waste settlement, liner strains and earthquake accelerations at various locations throughout the model. This data on landfill and liner seismic performance has been supplemented with additional laboratory and small scale centrifuge tests to determine the parameters required for the numerical model, including strength and stiffness of the model materials, interface shear strengths, and interface stiffness. The numerical model explicitly assesses the forces and strains in the geomembrane elements of a containment system to subject to both static and seismic loads the computer code FLACTM, a finite difference program for non-linear analysis of continua. The model employs a beam element with zero moment of inertia and with interface elements on both sides to model to represent the geomembrane elements in the liner system. The model also includes non-linear constitutive models for the stress-strain behavior of geomembrane beam elements and an elastic-perfectly plastic model for the load-displacement behavior of the beam interfaces. Parametric studies are conducted with the validated numerical model to develop recommendations for landfill design, construction, and construction quality assurance.
ContributorsWu, Xuan (Ph.D. in civil and environmental engineering) (Author) / Kavazanjian, Edward (Thesis advisor) / Zapata, Claudia (Committee member) / Jang, Jaewon (Committee member) / Arizona State University (Publisher)
Created2017