Induced chirality through electromagnetic coupling between chiral molecular layers and plasmonic nanostructures

We report a new approach for creating chiral plasmonic nanomaterials. A previously unconsidered, far-field mechanism is utilized which enables chirality to be conveyed from a surrounding chiral molecular material to a plasmonic resonance of an achiral metallic nanostructure. Our observations break a currently held preconception that optical properties of plasmonic particles can most effectively be manipulated by molecular materials through near-field effects. We show that far-field electromagnetic coupling between a localized plasmon of a nonchiral nanostructure and a surrounding chiral molecular layer can induce plasmonic chirality much more effectively (by a factor of 10(3)) than previously reported near-field phenomena. We gain insight into the mechanism by comparing our experimental results to a simple electromagnetic model which incorporates a plasmonic object coupled with a chiral molecular medium. Our work offers a new direction for the creation of hybrid molecular plasmonic nanomaterials that display significant chiroptical properties in the visible spectral region.     

Experimental and computational study on sintering of ceramic coating layers with complex porous structures

This study investigated the sintering behavior of an yttria-stabilized zirconia coating for thermal barrier coatings (TBCs) with a complicated porous structure via both experiment and simulation using the finite element method for samples with only a coating (free coating) and samples with coating on a substrate (constrained coating). Sintering and grain growth proceeded from the bottom of the coating, and the coating bent convex upward in the free coating. In the constrained coating, sintering and grain growth proceeded in a manner similar to the free coating; however, the degrees of sintering and grain growth were small. Furthermore, sintering and grain growth were delayed because of substrate constraints. As a simulation result, the free coating was bent in a manner similar to the experiment. The experimental results could be reproduced in terms of time dependency and temperature dependency. The decrease in the porosity of the constrained coating was delayed compared with that in the free coating because of substrate constraints. This simulation result was able to reproduce the experimental results. Thus, the sintering behavior for the complex porous structures of TBCs can be predicted by experimental research and simulation, which could aid in the development of a prediction technology for the delamination of coatings (TBC lifetime).     

REX-J: Japanese referring expression corpus of situated dialogs

Identifying objects in conversation is a fundamental human capability necessary to achieve efficient collaboration on any real world task. Hence the deepening of our understanding of human referential behaviour is indispensable for the creation of systems that collaborate with humans in a meaningful way. We present the construction of REX-J, a multi-modal Japanese corpus of referring expressions in situated dialogs, based on the collaborative task of solving the Tangram puzzle. This corpus contains 24 dialogs with over 4?h of recordings and over 1,400 referring expressions. We outline the characteristics of the collected data and point out the important differences from previous corpora. The corpus records extra-linguistic information during the interaction (e.g. the position of pieces, the actions on the pieces) in synchronization with the participants’ utterances. This in turn allows us to discuss the importance of creating a unified model of linguistic and extra-linguistic information from a new perspective. Demonstrating the potential uses of this corpus, we present the analysis of a specific type of referring expression (“action-mentioning expression”) as well as the results of research into the generation of demonstrative pronouns. Furthermore, we discuss some perspectives on potential uses of this corpus as well as our planned future work, underlining how it is a valuable addition to the existing databases in the community for the study and modeling of referring expressions in situated dialog.     

Clustering triple microbeads in a dynamic microarray for timing-controllable bead-based reactions

In this study, we developed a dynamic microfluidic device that enables the clustering of three different types of microbeads in a trapping spot and the rearrangement of contacting modes of the clustered microbeads. To achieve these two functions, two features are added to the conventional dynamic microfluidic device. (1) To trap multiple beads, an extended trapping spot with sub-by-pass channels and a valve was employed. (2) To rearrange the clustered microbeads, trapping spots that work only by backward flow were added. The design of the microfluidic device was realized by calculations based on fluidic resistance. By using the designed device, we successfully clustered different types of hydrogel microbeads including target materials, and observed reactions between clustered microbeads. In addition, by rearranging the contacting modes of the clustered microbeads, the reaction could be initiated/terminated at the desired time. We found that this dynamic microfluidic device is applicable to the quantitative analysis of chemical reactions between small amounts of multiple materials.     

Spectroscopic properties of Er doped and Er, Nd codoped fluoride glasses under simulated sunlight illumination

We investigated the fluorescence characteristics of Er codoped Nd doped ZBLAN glasses proposed for solar pumped fiber laser (SPFL) under simulated sunlight. Er is used as a sensitizer because it absorbs a part of the ultraviolet and visible light where is no absorption of Nd. Under simulated sunlight illumination, Er singly doped fluoride glass displayed four emission bands with peaks at 550, 848, 977 and 1533 nm attributed to the ⁴S_3/2-⁴I_15/2, ⁴S_3/2-⁴I_13/2, ⁴I_11/2-⁴I_15/2 and ⁴I_13/2-⁴I_15/2 electronic transitions of Er, respectively. The quantum efficiency measurement was carried out using an integrating sphere and under the simulated sunlight excitation showed a maximum of 73% for 0.5 mol.% of ErF₃ in ZBLAN glass. In Nd, Er codoped fluoride glass, the 1.05 μm emission of Nd was observed under 380 nm excitation what supposes the energy transfer from Er to Nd in ZBLAN glasses as Nd has no absorption at the wavelength. Er, Nd codoped fluoride glasses are promising as a sensitized laser media for solar pumped fiber lasers.     

Characterization of Spaghetti Prepared Under Different Drying Conditions

Spaghetti dried at low (max. 50 °C), high (max. 70 °C), and very high (max. 85 °C) temperatures were characterized by their color, surface structure, rupture strength, texture analysis, and sauce retention capacity. The texture and sauce retention capacity were estimated for cooked spaghetti. The color of the spaghetti's methanol extracts, as evaluated through absorbance at 440 and 466 nm, did not depend on the drying temperature. A trend was observed in the surface texture of spaghetti, as estimated by atomic force microscopy and mercury intrusion porosimetry, where the surface was rougher when dried at higher temperatures than at low temperatures. Furthermore, the rupture strength was also higher for the spaghetti dried at higher temperatures. This result can be ascribed to the formation of stronger gluten networks, promoted by denaturation of gluten at the higher temperatures. However, the hardness of cooked spaghetti was not affected by the drying temperature, a result attributable to the action of water sorption to offset any differences in hardness among the spaghettis dried at the 3 different temperatures. The sauce retention capacity of cooked spaghetti was evaluated using a dextran solution as a simulated sauce, and by this method, the capacity of the spaghetti dried at a low temperature was shown to be significantly lower than that of the spaghetti dried at higher temperatures. This can be ascribed to the smoother surface of cooked spaghetti dried at the lower temperature and also to the leakage of amylose onto the surface during cooking.     

Measurement of Moisture Profiles in Pasta During Rehydration Based on Image Processing

A method using an image processing technique was developed to measure the moisture profile in pasta during its rehydration process. The method is based on the increase in sample color brightness with increasing moisture content. Compared to currently used methods, this method has the advantage that moisture contents around 0.1 kg-H₂O/kg-d.m. can be easily measured at a spatial resolution of 1.6 μm. The moisture profiles obtained by this method suggested that penetration of water into small holes and cracks on the pasta surface, water diffusion in the pasta, and structural relaxation of the protein matrix play important roles in the rehydration mechanism. It was also suggested that starch granule gelatinization prevented water migration into the interior portion of the pasta.     

Tensile elongation of high‐fluid polypropylene/ethylene–propylene rubber blends: Dependence on molecular weight of the components and propylene content of the rubber

We studied tensile behavior of low‐molecular‐weight (MW) polypropylene (PP)/ethylene–propylene rubber (EPR; 70/30) blends from the viewpoint of the MWs of PP and EPR and the compatibility between PP and EPR. The value of the melt flow rate of PP varied from 30 to 700 g/10 min at 230°C. We studied the compatibility between PP and EPR by varying the propylene content in EPR (27 and 68 wt %). At the initial elongation stage, crazes were observed in all blends. When blends included EPR with 27 wt % propylene, the elongation at break of the low‐MW PP improved little. The blends with EPR and 68 wt % propylene content were elongated further beyond their yielding points. The elongation to rupture was increased with increasing MW of EPR. Molecular orientation of the low‐MW PP was manifested by IR dichroism measurements and X‐ray diffraction patterns. The blends of low‐MW PP and EPR could be elongated by the partial dissolution of EPR of high‐MW in the PP amorphous phase. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 46–56, 2002     

Orientation Mediated Enhancement on Magnetic Hyperthermia of Fe3O4 Nanodisc

A two‐step chemical approach to synthesize high quality Fe₃O₄ nanodisc is reported. The magnetic hyperthermia properties of the nanodisc and isotropic nanoparticles are investigated systematically. The results suggest that the nanodisc shows much higher specific absorption rate (SAR) than isotropic nanoparticles. This is attributed to the parallel alignment of nanodisc with respect to the alternating current magnetic field, which is confirmed by good agreement between experimental results and micromagnetic simulation. It is found that such parallel alignment could enhance the SAR value by a factor of ≈2 with respect to the randomly oriented case. The above results indicate that the nanodisc provides an excellent thermal seed for magnetic hyperthermia. This study sheds the light on the magnetic hyperthermia mechanism of magnetic nanodisc and it also opens the window to explore high efficiency thermal seeds by controlling the orientation of magnetic nanostructures.