Burying straw men in imaginary graves: a reply to Kewley-Port, Watson, and Foyle (1988)

Kewley-Port, Watson, and Foyle [J. Acoust. Soc. Am. 83, 1133-1145 (1988)] describe a study that uses several different procedures to measure thresholds for stimuli whose components differ in temporal onset. Unfortunately, misunderstandings and misconceptions (shared with other recent publications) resulted in conclusions that are both unnecessary and unwarranted. The Kewley-Port et al. article is discussed in terms of often replicated published findings on temporal order thresholds, and current misconceptions of perceptual concepts and models.     

Computational modelling of TiO2 surfaces sensitized by organic dyes with different anchoring groups: adsorption modes, electronic structure and implication for electron injection/recombination

We present a Density Functional Theory investigation aimed to model the possible adsorption modes to the TiO(2) surface of two representative TPA-based dyes, termed L0 and rh-L0, having the two mostly employed anchoring groups, namely the cyanoacrylic and rhodanine-3-acetic acids respectively. The bidentate coordination with proton transfer to a nearby surface oxygen is found to be the energetically favored anchoring mode for both dyes. The calculations show that the different dye anchoring groups give rise to a very different electronic coupling between the dye and the manifold of unoccupied semiconductor states, thus implying different electron injection mechanisms. The strongly coupled L0 dye possibly shows an adiabatic electron injection mechanism, while a non-adiabatic electron injection can be foreseen for the weakly coupled rh-L0 dye. The different orientation with respect to the TiO(2) surface for the two classes of dyes, implying different distances of the donor group from the oxide surface, together with the different electron injection mechanisms might account for the faster recombination reaction measured for the rhodanine-based dyes.