Cultural differences in prejudice between individual- and group-oriented cultures

The present dissertation investigated cultural differences in the degree and dynamics of prejudice between individual- and group-oriented cultures. In Study 1, in the US where personal responsibility and individual's capitalistic/meritocratic achievements are emphasized, participants reported greater distance to groups based on personal qualities (e.g., heavy drinkers) than in South Korea, and competition for employment was positively associated with prejudice toward various groups (but not in South Korea). In South Korea where the holistic/essential quality, the self-ingroup overlap, and relationships within ingroups are emphasized, participants reported greater distance to groups perceived as essentially different from the majority (e.g., different race) than in the US. In Study 2, the emphasis on individual achievements consistently predicted social hierarchy beliefs in the US (but not in South Korea), whereas the emphasis on roles/positions within ingroups consistently predicted both social and biological hierarchy beliefs in South Korea (but not in the US). In Study 3, the emphasis on individual uniqueness was negatively associated with social distance to non-normative groups (e.g., homosexuals) only in the US, whereas the value of conformity with norms/conventions predicted social distance to low SES (e.g., poor/uneducated/homeless), non-normative, and value-based (e.g., people whose opinions are different from mine in religious issues) target groups both in the US and South Korea. Conformity with norms/conventions also predicted social distance to racial/ethnic outgroups (e.g., non-Koreans to South Korean participants) only in South Korea. In addition, essentialism was associated with social distance to low SES groups in the US, whereas essentialism was associated with social distance to low SES, non-normative, and racial/ethnic groups in South Korea. Overall, the present research provided empirical evidence that cultural norms/values are associated with differences in the degree and dynamics of prejudice between individual- and group-oriented cultures

Synergy between Fe and Ni in the optimal performance of (Ni,Fe)OOH catalysts for the oxygen evolution reaction

The oxygen evolution reaction (OER) is critical to solar production of fuels, but the reaction mechanism underlying the performance for a best OER catalyst, Fe-doped NiOOH [(Ni,Fe)OOH], remains highly controversial. We used grand canonical quantum mechanics to predict the OER mechanisms including kinetics and thus overpotentials as a function of Fe content in (Ni,Fe)OOH catalysts. We find that density functional theory (DFT) without exact exchange predicts that addition of Fe does not reduce the overpotential much. However, DFT with exact exchange predicts dramatic improvement in performance for (Ni,Fe)OOH, leading to an overpotential of 0.42 V and a Tafel slope of 23 mV/decade (dec), in good agreement with experiments, 0.3–0.4 V and 30 mV/dec. We reveal that the high spin d^4 Fe(IV) leads to efficient formation of an active O radical intermediate, while the closed shell d^6 Ni(IV) catalyzes the subsequent O–O coupling, and thus it is the synergy between Fe and Ni that delivers the optimal performance for OER

Photochemically deposited Ir-doped NiCo oxyhydroxide nanosheets provide highly efficient stable electrocatalysts for the oxygen evolution reaction

To achieve practical production of fuel from water, it is essential to develop efficient and durable electrocatalysts for the oxygen evolution reaction (OER). We report here that doping NiCoOOH nanosheets with 8% Ir leads to a low overpotential of only 260 mV for 50 mA/cm², far better than previous OER catalysts. We synthesized this catalyst using a novel photochemical deposition method that leads to a uniform distribution of dopant, large catalytic active area, high interfacial charge transfer efficiency, good adhesion between catalyst and matrix, and long lifetime. Moreover, these nanosheets show significant stable performance for 70 h in alkaline media. Our density functional theory calculations show that Ir and Co both play essential bifunctional roles in stabilizing the key O radical intermediate on Ir and promoting the O–O bond coupling on Co, which are optimum for the 8% Ir

Synergy between Fe and Ni in the optimal performance of (Ni,Fe)OOH catalysts for the oxygen evolution reaction

The oxygen evolution reaction (OER) is critical to solar production of fuels, but the reaction mechanism underlying the performance for a best OER catalyst, Fe-doped NiOOH [(Ni,Fe)OOH], remains highly controversial. We used grand canonical quantum mechanics to predict the OER mechanisms including kinetics and thus overpotentials as a function of Fe content in (Ni,Fe)OOH catalysts. We find that density functional theory (DFT) without exact exchange predicts that addition of Fe does not reduce the overpotential much. However, DFT with exact exchange predicts dramatic improvement in performance for (Ni,Fe)OOH, leading to an overpotential of 0.42 V and a Tafel slope of 23 mV/decade (dec), in good agreement with experiments, 0.3–0.4 V and 30 mV/dec. We reveal that the high spin d^4 Fe(IV) leads to efficient formation of an active O radical intermediate, while the closed shell d^6 Ni(IV) catalyzes the subsequent O–O coupling, and thus it is the synergy between Fe and Ni that delivers the optimal performance for OER

Current Trends in Korean Adolescents’ Social Purpose

In the research presented we investigated the features of Korean adolescents’ social purpose as compared with other life goals in terms of different aspects of psychological well-being (study 1). We also examine the perceptions of high achieving Korean adolescents on social purpose and factors affecting it (study 2).The results of study 1 showed that the pursuit of social purpose significantly predicted psychological well-being compared to the other two life goals. Results of study 2 showed Korean adolescents value and pursue social purpose as a life goal. They explicitly accepted their social responsibility to serve their country in line with idyllic Confucianism values and Collectivistic roles. However, further analysis revealed that they had implicitly pursued individualistic desires of materialistic wealth and fame in parallel with their explicit social purpose. Implications of the results are discussed from the socio-cultural perspective on social purpose in regards to how to understand the features of social purpose that Korean adolescents have and how to foster its development

Scaled Effective Solvent Method for Predicting the Equilibrium Ensemble of Structures with Analysis of Thermodynamic Properties of Amorphous Polyethylene Glycol–Water Mixtures

Water-soluble polymers such as polyethylene glycol (PEG) are critical components of industrial processes ranging from drug delivery to water purification. However, the understanding of the microscopic structure of these polymers in water and of the thermodynamics of the mixtures is limited because available experimental techniques (such as SLS and SANS) give little information about conformations and provide even the radius of gyration only in the dilute limit (~<5 wt % PEG). Computer simulations employing Monte Carlo (MC) and molecular dynamics (MD) techniques can provide an atomistic molecular structure; however, such approaches have difficulties in predicting the equilibrium polymer configurations of high-molecular-weight polymers at normal densities and in obtaining entropies and free energies directly from the MD. Here, we develop the scaled effective solvent (SES) method to predict the equilibrium ensemble of polymer configurations, which we illustrate for the case of a 20 kDa PEG (455 monomers) at a 25 wt % PEG aqueous solution (3339 waters per PEG chain). We evaluate the free energy and entropy of the members of this ensemble including explicit water, validating that it leads to average sizes (R_g) observed experimentally and that all members of the ensemble have favorable free energies. With the SES method validated to provide well-equilibrated polymer chains in water, it should be useful for predicting ensembles of polymer chains in polymer melts and in solvents

Ga-doped Pt-Ni Octahedral Nanoparticles as a Highly Active and Durable Electrocatalyst for Oxygen Reduction Reaction

Bimetallic PtNi nanoparticles have been considered as a promising electrocatalyst for oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) owing to their high catalytic activity. However, under typical fuel cell operating conditions, Ni atoms easily dissolve into the electrolyte, resulting in degradation of the catalyst and the membrane-electrode assembly (MEA). Here, we report gallium-doped PtNi octahedral nanoparticles on a carbon support (Ga-PtNi/C). The Ga-PtNi/C shows high ORR activity, marking an 11.7-fold improvement in the mass activity (1.24 A mgPt-1) and a 17.3-fold improvement in the specific activity (2.53 mA cm-2) compare to the commercial Pt/C (0.106 A mgPt-1 and 0.146 mA cm-2). Density functional theory calculations demonstrate that addition of Ga to octahedral PtNi can cause an increase in the oxygen intermediate binding energy, leading to the enhanced catalytic activity toward ORR. In a voltage-cycling test, the Ga-PtNi/C exhibits superior stability to PtNi/C and the commercial Pt/C, maintaining the initial Ni concentration and octahedral shape of the nanoparticles. Single cell using the Ga-PtNi/C exhibits higher initial performance and durability than those using the PtNi/C and the commercial Pt/C. The majority of the Ga-PtNi nanoparticles well maintain the octahedral shape without agglomeration after the single cell durability test (30,000 cycles). This work demonstrates that the octahedral Ga-PtNi/C can be utilized as a highly active and durable ORR catalyst in practical fuel cell applications