Ultrafast resonant optical scattering from single gold nanorods: Large nonlinearities and plasmon saturation

We measure nonlinear optical scattering from individual Au nanorods excited by ultrafast laser pulses on resonance with their longitudinal plasmon mode. Isolating single rods removes inhomogeneous broadening and allows the measurement of a large nonlinearity, much greater than that of nanorod ensembles. Surprisingly, the ultrafast nonlinearity can be attributed entirely to heating of conduction electrons and does not exhibit any response associated with coherent plasmon oscillation. This indicates a previously unobserved damping of strongly driven plasmons.Comment: Revised tex

The social dimension of urban design as a means of engendering community engagement in urban regeneration

PhD ThesisThe contribution to knowledge of this thesis is to suggest the potential of urban design through an integrated linkage between the social role of urban design and community engagement in urban regeneration as a response of the advocacy of participative urban design approach and the academic debate of community engagement. This thesis explores the social dimension of urban design in urban regeneration with the contexts of urban policies in England and South Korea. The thesis progresses a detailed empirical investigation of urban design in both countries’ urban regeneration practices, principally Scotswood and Walker Riverside in Newcastle upon Tyne, UK and Singil in Seoul, South Korea. It illustrates that urban design plays various roles in urban regeneration in physical and social aspects, concerning improving physical environments, local resident’s liveability, and tackling social problems. It also identifies challenges for urban design in urban regeneration in relation to various tensions in the practice of urban regeneration. How local communities are engaged in the wider process of urban regeneration practices is illustrated in this thesis. The exploration of urban regeneration practices explains the mechanisms for identifying community views in relation to urban design. It identifies factors affecting community engagement and channels for community engagement in the process of urban design in urban regeneration and underlines community engagement in the management of end-products of urban design. The thesis concludes with a discussion about the social dimension and the potentials of urban design in urban regeneration. It highlights that urban design plays a role in community engagement, as a means of engendering community engagement in urban regeneration. It discusses the potential of urban design as a process of integration, as a responsible process to the social consequences of urban regeneration, and as proactive actions for the delivery of better urban design and as reactive actions for the iii management of the built environment. It also recommends actions in the process of urban design for local communities in Korean urban regeneration practices. Overall, this thesis highlights that there is a need to be a shift in the perspectives of urban design in urban regeneration towards urban design as a collaborative and an ongoing process of making better places, concerning not only improving existing urban environment and the quality of life for users, but also the management of the built environments the legacy of urban regeneration

Common Mode Noise Reduction for an LLC Resonant Converter by Using Passive Noise Cancellation

This paper describes the application of a passive noise cancellation method to a prototype inductor-inductor-capacitor (LLC) resonant converter by placing a compensation winding in a transformer to reduce common mode noise. The connection method for the compensation winding is investigated. A circuit analysis is implemented for the displacement currents between the primary and secondary windings in the transformer. The analyzed displacement currents are verified by performing a circuit simulation and a proper compensation winding connection that reduces common mode noise is found. The measurement results show that common mode noise is reduced effectively up to 20 dB in the 1 to 7 MHz frequency region for the prototype LLC resonant converter by using the proposed passive noise cancellation method.clos

Complexation dynamics of CH₃SCN and Li⁺ in acetonitrile studied by two-dimensional infrared spectroscopy

A chemical exchange 2DIR study of ion–molecule complexation dynamics in electrolyte solutions.</p

Experimental Study on Flexural Behavior of TRM-Strengthened RC Beam: Various Types of Textile-Reinforced Mortar with Non-Impregnated Textile

In this study, to compare strengthening efficiency and flexural behaviors of textile- reinforced mortar (TRM) according to various types of strengthening methods without the textile being impregnated, ten specimens were tested. The results showed that TRM was beneficial for uniform distribution of cracks and increased the strengthening efficiency and load-bearing capacity, as textile reinforcement ratio and textile lamination increased and the mesh size of the textile decreased and mechanical end anchorage applied. However, the strengthening effect was shown obviously until the yield load considering structural safety and serviceability.</jats:p

Evaluation of Flexural Behavior of Textile-Reinforced Mortar-Strengthened RC Beam Considering Strengthening Limit

Textile-reinforced mortar (TRM) is a strengthening material in which textiles are attached to reinforced concrete (RC) structures using an inorganic matrix. Although many studies on structural behavior, various factors that affect TRM behavior could not be determined clearly. Especially, the uncertainty in bonds due to inorganic materials was not considered. In this study, the flexural behavior of TRM-strengthened beams was determined considering intermediate crack debonding occurred. The TRM beam strengthening limit and TRM coefficients were defined considering the possibility of premature failure and experimental results of four other research on 22 specimens. Therefore, it is expected that a conservative design would be possible when the suggested strengthening limit coefficient is applied.</jats:p