123 research outputs found
are the East German workers still affected by the experience under communist regime?
No full textThesis(Master) --KDI School:Master of Development Policy,2017This research aims to find the impact of the institutional differences between the regimes of East and West Germany on job satisfaction and discretion. By using the division of Germany for 45 years after the World War II as a natural experimental setting with the data from the German Socio-Economic Panel (SOEP) from 1990 to 2009, I find that the workers of East German origin (the Easterners) have a lower level of job satisfaction after 20 years of the German reunification compared to their western counterparts. In addition, when the same amount of job discretion is granted, the Easterners exhibited a higher level of job satisfaction since they might be more appreciative of job discretion that they could not experience under the communist regime. However, this phenomenon disappeared after ten years. I also investigate the impact of migration to the region of West Germany after the reunification from East Germany. I found that among Easterners, migrants had higher job satisfaction than non-migrants but migrants experienced lesser increase in job satisfaction determined by job discretion.I. Introduction
II. Literature review
III. Hypothesis, Data, and Empirical Strategy
IV. Result
V. Discussion and Conclusion
VI. ReferencesOutstandingmasterpublishedKyungwon LIM
Ultrafast Continuum IR Generation and Its Application in IR Spectroscopy
No full textThe spectral range of femtosecond time-resolved infrared spectroscopy is limited by the bandwidth of mid-IR pulses (100~400 cm−1) generated from the combination of Ti:Sapphire amplifier, Optical Parametric Amplifier (OPA), and Difference Frequency Generation (DFG). To overcome this limitation, we implement a compact continuum mid-IR source producing ultrafast pulses that span the frequency range from 1000 to 4200 cm−1 (from 10 to 2.4 μm), which utilize the mixing of fundamental, second-harmonic, and third-harmonic of 800 nm pulse in the air. After building an IR spectrometer with continuum IR and a monochromator, we found that the distortion of the measured IR spectrum originated from the contamination of higher-order diffraction. We used bandpass filters to eliminate the higher-order contributions and correct the measured IR spectrum. We further characterized the spectral properties of fundamental, second-harmonic, and third-harmonic fields after the plasmonic filamentation process, which helps to improve the efficiency of the continuum IR generation. Using the generated continuum IR pulses, we measured the IR absorption spectrum of a water–benzonitrile mixture, which was found to be consistent with the spectrum obtained with a commercial FT-IR spectrometer. The present work will be useful for the efficient generation of continuum IR pulses for IR pump-probe and two-dimensional IR spectroscopy experiments in the future
Dynamic Water Promotes Lithium-Ion Transport in Superconcentrated and Eutectic Aqueous Electrolytes
No full textSuperconcentrated aqueous electrolytes have shown promise as safe and high-voltage lithium-ion battery (LIB) electrolytes. However, the interplay of lithium-ion solvation structure and dynamics with fast Li-ion transport has not been elucidated yet. Here, we combine the ultrafast femtosecond mid-IR spectroscopy, dielectric relaxation spectroscopy, pulsed-field gradient NMR, and molecular dynamics simulation for investigating the solvation structure and Li-ion transport mechanism in superconcentrated aqueous electrolytes. We found the existence of water molecules with vibrational and rotational properties very similar to those of bulk water, even at extremely high salt concentrations (28 m). Our experimental results show that the electrolytes have a heterogeneous solvation environment, and bulk-like water molecules promote fast Li-ion transport. We anticipate that the molecular understanding of the superconcentrated aqueous electrolytes obtained here would facilitate the design of solvation structures to overcome the limit of dilute LIB electrolytes.11Nsciescopu
Direct observation of protein structural transitions through entire amyloid aggregation processes in water using 2D-IR spectroscopy
No full text© 2022 The Royal Society of ChemistryAmyloid proteins that undergo self-assembly to form insoluble fibrillar aggregates have attracted much attention due to their role in biological and pathological significance in amyloidosis. This study aims to understand the amyloid aggregation dynamics of insulin (INS) in H2O using two-dimensional infrared (2D-IR) spectroscopy. Conventional IR studies have been performed in D2O to avoid spectral congestion despite distinct H-D isotope effects. We observed a slowdown of the INS fibrillation process in D2O compared to that in H2O. The 2D-IR results reveal that different quaternary structures of INS at the onset of the nucleation phase caused the distinct fibrillation pathways of INS in H2O and D2O. A few different biophysical analysis, including solution-phase small-angle X-ray scattering combined with molecular dynamics simulations and other spectroscopic techniques, support our 2D-IR investigation results, providing insight into mechanistic details of distinct structural transition dynamics of INS in water. We found the delayed structural transition in D2O is due to the kinetic isotope effect at an early stage of fibrillation of INS in D2O, i.e., enhanced dimer formation of INS in D2O. Our 2D-IR and biophysical analysis provide insight into mechanistic details of structural transition dynamics of INS in water. This study demonstrates an innovative 2D-IR approach for studying protein dynamics in H2O, which will open the way for observing protein dynamics under biological conditions without IR spectroscopic interference by water vibrations.11Nsciescopu
Solvation Structure around Li+Ions in Organic Carbonate Electrolytes: Spacer-Free Thin Cell IR Spectroscopy
No full text© 2021 American Chemical Society.Organic carbonate electrolytes are widely used materials for lithium-ion batteries. However, detailed solvation structures and solvent coordination numbers (CNs) of lithium cations in such solutions have not been accurately described nor determined yet. Because transmission-type IR spectroscopy is not of use for measuring the carbonyl stretch modes of electrolytes due to their absorption saturation problem, we here show that simple spacer-free thin cell IR spectroscopy can provide quantitative information on the number of solvating carbonate molecules around each lithium ion. We could estimate the solvent (carbonate) CNs of lithium ions in dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, propylene carbonate, and butylene carbonate over a wide range of lithium salt concentrations accurately, and they are compared with the previous results obtained with attenuated total reflection IR spectroscopy technique. We anticipate that our spacer-free thin cell approach will potentially be used to investigate the solvation dynamics, chemical exchange process, and vibrational energy transfers between solvating carbonate molecules in lithium salt electrolytes when combined with time-resolved IR spectroscopy.11Nsciescopu
A value chain process model of consumer co-creation activities
No full textWith path-breaking advances in technology, consumers have become more informed, connected, and empowered than ever before in hypermedia computer-mediated environments (CMEs). No longer passive recipients in the value creation process, consumers are increasingly active participants co-creating value through interactions with companies and other stakeholders. This has also triggered theoretical evolutions in the marketing discipline, extending from exchange to value creation to value co-creation paradigm. Now, value co-creation has emerged as the central theme in contemporary marketing with a growing body of literature to advance our understanding around the concept. However, there is lack of consensus on the definition, theoretical domains, or process of value co-creation, creating a need to provide an integration of the different existing perspectives around the concept in the literature with empirical validation of the process. By integrating two primary theoretical perspectives on co-creation in the literature (technology and innovation management perspective and service science perspective), my dissertation examines the antecedents and consequences of a wide spectrum of consumer value co-creation activities, ranging from pre-launch (i.e. co-ideation, co-test, co-design, and co-finance) to post-launch (co-promotion, co-distribution, co-maintenance, and co-price). The objective of this paper is to empirically examine the entire process of value co-creation from the marketer-initiated co-production efforts, such as B2C and C2C interaction, equity, and knowledge sharing, to consumers’ value-in-use through experience, relationship, customization, and satisfaction across a variety of value co-creation activities. Using the online video gaming industry as a context for data collection, a total of 561 online video game players completed the survey. Survey-based data collected to test the proposed framework was analyzed using structural equation modeling approach. The results show that pre-launch and post-launch co-creation have different sets of significant antecedents and consequences. As for the drivers of dual forms of interaction (B2C and C2C interaction) knowledge sharing has a positive effect on both B2C interaction and C2C interaction while equity positively impacts B2C interaction only. The influence of consumer motivations varies depending on the nature of interactions. While economic motivation is the only primary predictor for B2C interaction, C2C interaction is found to be influenced by social motivation and psychological motivation. As for the consequences of C2C and B2C interactions, they have different effect on consumer participation in pre- and post-launch co-creation activities. C2C interaction has positive effect on both pre- and post-launch co-creation activities, while B2C interaction has direct positive impact only on pre- not on post-launch co-creation activities; yet indirect effect on post-launch co-creation activities through C2C interaction. Interestingly, this indicates that C2C interaction fully mediates the relationship between B2C interaction and consumer participation in post-launch co-creation activities. Consumers’ co-created outcomes (i.e. value-in-use) are influenced differently depending on consumer participation in pre- vs. post-launch stages. While perceived level of customer relationship and satisfaction are highly influenced regardless of the types of consumer co-creation participation, experience is impacted only by post-launch co-creation participation while personalization is impacted only by pre-launch co-creation participation.Ph.D.Includes bibliographical referencesby Kyungwon Le
Parks as a Visionary or Media Device: An Approach of“ Promise Park” by Moon Kyungwon
No full textThis paper deals wite “Promise Park,” a project initiated by a team including Korean artist Moon Kyungwon and the author himself. “Promise Park” raises the question of what future parks would look like, why parks have existed in the history of civilization, and what kind of role they serve within the urban structure. It approximates the park-like space as a whole, exploring topics such as the motifs and influences parks have carried within modern and contemporary art history, their relation to their predecessor of gardens, and their significance as voids within public spaces.departmental bulletin pape
Revisiting Ultrafast Dynamics in Carbonate-Based Electrolytes for Li-Ion Batteries: Clarifying 2D-IR Cross-Peak Interpretation
No full textUnderstanding chemical exchange in carbonate-based electrolytes employed in Li-ion batteries (LIBs) is crucial for elucidating ion transport mechanisms. Ultrafast two-dimensional (2D) IR spectroscopy has been widely used to investigate the solvation structure and dynamics of Li-ions in organic carbonate-based electrolytes. However, the interpretation of cross-peaks observed in picosecond carbonyl stretch 2D-IR spectra has remained contentious. These cross-peaks could arise from various phenomena, including vibrational couplings between neighboring carbonyl groups in the first solvation shell around Li-ions, vibrational excitation transfers between carbonyl groups in distinct solvation environments, and local heating effects. Therefore, it is imperative to resolve the interpretation of 2D-IR cross-peaks to avoid misinterpretations regarding ultrafast dynamics found in LIB carbonate-based electrolytes. In this study, we have taken a comprehensive investigation of carbonate-based electrolytes utilizing 2D-IR spectroscopy and molecular dynamics (MD) simulations. Through meticulous analyses and interpretations, we have identified that the cross-peaks observed in the picosecond 2D-IR spectra of LIB electrolytes predominantly arise from intermolecular vibrational excitation transfer processes between the carbonyl groups of Li-bound and free carbonate molecules. We further discuss the limitations of employing a picosecond 2D-IR spectroscopic technique to study chemical exchange and intermolecular vibrational excitation transfer processes, particularly when the effects of the molecular photothermal process cannot be ignored. Our findings shed light on the dynamics of LIB electrolytes and resolve the controversy related to 2D-IR cross-peaks. By discerning the origin of these features, we could provide valuable insights for the design and optimization of next-generation Li-ion batteries.11Nsciescopu
Adsorbed Water Structure on Acrylate-Based Biocompatible Polymer Surface
No full text© 2021 American Chemical Society.The role of water in the excellent biocompatibility of the acrylate-based polymers widely used for antibiofouling coating material has been realized previously. Here, we report femtosecond mid-infrared pump-probe spectroscopy of the OD stretch band of HOD molecule adsorbed on highly biocompatible poly(2-methoxyethyl) acrylate [PMEA] and poorly biocompatible poly(2-phenoxyethyl) acrylate [PPEA], both of which reveal that there are two water species with significantly different vibrational lifetime. PMEA interacts more strongly with water than PPEA through the H-bonding interaction between carbonyl (CO) and water. The vibrational lifetime of the OD stretch in PPEA is notably longer by factors of 3 and 7 than those in PMEA and bulk water, respectively. The IR-pump visible-probe photothermal imaging further unravels substantial spatial overlap between polymer CO group and water for hydrated PMEA and a significant difference in surface morphology than those in PPEA, which exhibits the underlying relationships among polymer-water interaction, surface morphology, and biocompatibility.11Nsciescopu
Ultrafast intraband Auger process in self-doped colloidal quantum dots
No full textInvestigating the separate dynamics of electrons and holes has been challenging, although it is critical for the fundamental understanding of semiconducting nanomaterials. n-Type self-doped colloidal quantum dots (CQDs) with excess electrons occupying the low-lying state in the conduction band (CB) have attracted a great deal of attention because of not only their potential applications to infrared optoelectronics but also their intrinsic system that offers a platform for investigating electron dynamics without elusive contributions from holes in the valence band. Here, we show an unprecedented ultrafast intraband Auger process, electron relaxation between spin orbit coupling states, and exciton-to-ligand vibrational energy transfer process that all occur exclusively in the CB of the self-doped beta-HgS CQDs. The electron dynamics obtained by femtosecond mid infrared spectroscopy will pave the way for further understanding of the blinking phenomenon, disproportionate charging in light-emitting diodes, and hot electron dynamics in higher quantum states coupled to surface states of CQDs.11Nsciescopu
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