The design and evaluation of an auditory way-finding system in a train station

Previous studies have shown that auditory cues contribute to the identification of several components of a public space such as the volume, but also the type of activity to which the space is dedicated. This paper demonstrates that solutions to improve way-finding in a public place can be based on providing additional auditory information. A methodical approach in three phases is proposed and applied in the case of a train station. First, problems encountered by travellers in a train station are identified by way of an ergonomic study under real conditions with recruited travellers. The results reveal three kinds of problems: orientation errors, lack of confirmation of direction, and lack of information about the remaining distance to be covered. In the second phase, functional and environmental specifications were developed in order to create sound signals for each identified problem. A sound designer proposed several non-speech sound signals based on two schemas: a pair of sounds for the orientation and confirmation functions, and a timeline sequence for the remaining distance. Finally, in the third phase, the sound signals were installed in the train station using an experimental broadcasting system and were evaluated in a second ergonomic study using the same method. The results show that the number of orientation errors decreased and that participants felt more confident during their walk. Sound signals for the orientation and confirmation functions were understood and used by the participants. However, the timeline sequence signalling remaining distance was not understood.     

A high-sensitivity terahertz sensing method using a metallic mesh with unique transmission properties

Metallic meshes work as band-pass filters in the terahertz (THz) region, with their transmission spectra acutely affected by the refractive index of the material inside and above the metallic-mesh openings. We used a metallic mesh for high-sensitivity observations by focusing on the “dip,” that is, a sudden change in transmittance that only appeared when the THz wave was obliquely incident onto the metallic mesh. Here we consider the interference between apertures of the metallic mesh in the diagonal direction and explain the dip using finite-difference time-domain (FDTD) electromagnetic simulations.     

Characterization of interface of Al-Ni/a-Si for thin film transistor using high-resolution Rutherford backscattering spectrometry

High-resolution Rutherford backscattering spectrometry (HRBS) in combination with grazing angle argon sputtering was carried out to characterize the interface of aluminum-nickel (Al-Ni) alloy and amorphous-silicon films in a thin film transistor (TFT) for liquid crystal display (LCD). After thinning the top Al-Ni layer by a 1-keV Ar sputtering, the sensitivity of the interface oxygen was improved to be twice higher than that before sputtering. The results revealed that the oxygen at the interface relates to the contact characteristics.     

Synthesis of Dinuclear Mo−Fe Hydride Complexes and Catalytic Silylation of N2

Two transition-metal atoms bridged by hydrides may represent a useful structural motif for N₂ activation by molecular complexes and the enzyme active site. In this study, dinuclear Mo^IV-Fe^II complexes with bridging hydrides, Cp^RMo(PMe₃)(H)(μ-H)₃FeCp* ( 2 a ; Cp^R=Cp*=C₅Me₅, 2 b ; Cp^R=C₅Me₄H), were synthesized via deprotonation of Cp^RMo(PMe₃)H₅ ( 1 a ; Cp^R=Cp*, 1 b ; Cp^R=C₅Me₄H) by Cp*FeN(SiMe₃)₂, and they were characterized by spectroscopy and crystallography. These Mo−Fe complexes reveal the shortest Mo−Fe distances ever reported (2.4005(3) Å for 2 a and 2.3952(3) Å for 2 b ), and the Mo−Fe interactions were analyzed by computational studies. Removal of the terminal Mo−H hydride in 2 a – 2 b by [Ph₃C]⁺ in THF led to the formation of cationic THF adducts [Cp^RMo(PMe₃)(THF)(μ-H)₃FeCp*]⁺ ( 3 a ; Cp^R=Cp*, 3 b ; Cp^R=C₅Me₄H). Further reaction of 3 a with LiPPh₂ gave rise to a phosphido-bridged complex Cp*Mo(PMe₃)(μ-H)(μ-PPh₂)FeCp* ( 4 ). A series of Mo−Fe complexes were subjected to catalytic silylation of N₂ in the presence of Na and Me₃SiCl, furnishing up to 129±20 equiv of N(SiMe₃)₃ per molecule of 2 b . Mechanism of the catalytic cycle was analyzed by DFT calculations.     

KINETIC STUDIES ON THE ACID-CATALYZED PUMMERER REACTION OF α-(METHYLSULFINY)ACETOPHENONES

Abstract

The kinetic behavior of the acid-catalyzed Pummerer reaction of α-(methylsulfinyl)acetophenones in dilute hydrochloric acid has been studied in detail. The kinetic data were analyzed in the light of correlations between the reaction rates and acidity functions, activation parameters, solvent isotope effects, polar effects of substituents, etc. Moreover, ¹⁸O-tracer experiments were also carried out using acid media containing H₂ ¹⁸O. Based on these observations, a plausible mechanism for this reaction has been discussed.