Period Changes in Intergenerational Income Mobility between Welfare State Contexts in South Korea and the United States

Thesis (Ph.D.)--University of Washington, 2019Social mobility has stalled or declined in most advanced welfare states in an era of rising inequality, implying that socioeconomic disadvantages persist across generations and questioning the permeable class structure premised by a capitalist democracy. Welfare state policies aim to enhance upward social mobility for the citizenry by reducing inequality and promoting inclusive growth; however, social mobility is rarely examined as embedded within the institutional and sociocultural contexts of alternative forms of the market economy welfare state. Although South Korea and the United States have generally similar residual and limited welfare state regimes, this dissertation finds that the intergenerational income mobility (IGM) trends in recent decades differ remarkably between the two countries; thus, this paradox becomes the focus of the dissertation. This dissertation analyzes cross-national differences in IGM in South Korea and the United States for two birth cohorts representing contrasting period effects: between 1980-1995 and 1996-2015, using data from the Korean Labor and Income Panel Study in South Korea and the Panel Study of Income Dynamics in the United States. It then conducts a historically informed comparative analysis of between-country mobility differences as contextualized by different philosophical underpinnings of the welfare state—Confucian familial orientation in South Korea vs. libertarian individualistic orientation in the United States. This study presents findings in four areas. First, findings suggest no period effects on IGM in both countries, though the Korean IGM improved and the U.S.’s IGM eroded. Second, results suggest that women’s IGM in Korea changed: shifting from less to more mobile than that of men between the two study periods; whereas in the United States, IGM eroded for both men and women, with the erosion of IGM particularly pronounced among women. Third, results indicate that not only income but also family structure impacts IGM in both countries. Finally, this dissertation theorizes that it is plausible that more favorable IGM trends in Korea might in part be attributable to the benefits of its Confucian Welfare State orientation, which emphasizes promoting family system support and responsibility, over the more individualistic orientation of the American welfare state

Recyclable and Mendable Cellulose-Reinforced Composites Crosslinked with Diels–Alder Adducts

Owing to their natural abundance and exceptional mechanical properties, cellulose fibers (CFs) have been used for reinforcing polymers. Despite these merits, dispersing hydrophilic CFs in a hydrophobic polymer matrix is challenging. To address this, an amphiphilic ammonium salt was employed as the dispersant for CFs in this study. The hydrophobic CFs were mixed with a healable polymer to produce CF-reinforced composites. As the thermosetting polymer was crosslinked with Diels–Alder (DA) adducts, it was mended and recycled via a retro DA reaction at 120 °C. Interestingly, the CF-reinforced polymer composites were mended and recycled as well. When 5 wt % of the hydrophobic CFs was added to the polymer, maximum tensile strength, elongation at break, Young’s modulus, and toughness increased by 70%, 183%, 75%, and 420%, respectively. After recycling, the CF-reinforced composites still featured better mechanical properties than recycled polymer

Hierarchical patterns of three-dimensional block-copolymer films formed by electrohydrodynamic jet printing and self-assembly

Self-assembly of block-copolymers provides a route to the fabrication of small (size, <50 nm) and dense (pitch, <100 nm) features with an accuracy that approaches even the demanding specifications for nanomanufacturing set by the semiconductor industry. A key requirement for practical applications, however, is a rapid, high-resolution method for patterning block-copolymers with different molecular weights and compositions across a wafer surface, with complex geometries and diverse feature sizes. Here we demonstrate that an ultrahigh-resolution jet printing technique that exploits electrohydrodynamic effects can pattern large areas with block-copolymers based on poly(styrene-block-methyl methacrylate) with various molecular weights and compositions. The printed geometries have diameters and linewidths in the sub-500 nm range, line edge roughness as small as similar to 45 nm, and thickness uniformity and repeatability that can approach molecular length scales (similar to 2 nm). Upon thermal annealing on bare, or chemically or topographically structured substrates, such printed patterns yield nanodomains of block-copolymers with well-defined sizes, periodicities and morphologies, in overall layouts that span dimensions from the scale of nanometres (with sizes continuously tunable between 13 nm and 20 nm) to centimetres. As well as its engineering relevance, this methodology enables systematic studies of unusual behaviours of block-copolymers in geometrically confined films