Search

Aim. Our purposes were to investigate: (a) differences in mood states between high and low performers at the beginning and end of the Girobio 2012 cycling race, and in respect to both actual and perceived performance; and (b) whether the participants’ mood states predicted actual and perceived performance. Methods. Profile of Mood States (POMS) of 72 elite cyclists were assessed the day prior to the first (T0) and last stage (T1). At the end of the race, we created two rankings, one based on the total time spent to complete the race (actual ranking) and one based on the average of self-evaluations provided at the end of each stage (perceived ranking). We compared high and low performers, considering both rankings, using a general measure of mood; i.e. the Total Mood Disturbance. Results. Total Mood Disturbance differed among high and low performers. In particular, high performers’ mood disturbance did not differ between T0 and T1, whereas low performing cyclists showed higher levels of mood disturbance at the end of the race. Furthermore, we found that mood disturbance at T0 did not predict either actual or perceived performance. Conclusions. The cyclists’ mood states at the beginning of the race are not reliable predictors of performance throughout the race. High performing cyclists maintained a more positive mood profile than their low performing counterparts at the beginning and end of a multi-stage race.

© 2015 American Chemical Society. Thin films of organic semiconductors have been widely studied at different length scales for improving the electrical response of devices based on them. Hitherto, a lot of knowledge has been gained about how molecular packing, morphology, grain boundaries, and defects affect the charge transport in organic thin film transistors. However, little is known about the impact of an electric field on the organic semiconductor microstructure and the consequent effect on the device performances. To fill this gap, we investigated the evolution of the structure of pentacene thin film transistors during device operation by in situ real time X-ray diffraction measurements and theoretical calculations. We observed for the first time the occurrence of a reversible structural strain taking place during the bias application mainly due to reorientation at the terrace edges of monolayer islands under the effect of electrical field. Strain exhibits the same trend of the threshold voltage hinting to the existence of a direct correlation between the phenomenon of bias stress and the structural modification.

We report on an artificial synapse, an organic synapse-transistor (synapstor) working at 1 volt and with a typical response time in the range 100-200 ms. This device (also called NOMFET, Nanoparticle Organic Memory Field Effect Transistor) combines a memory and a transistor effect in a single device. We demonstrate that short-term plasticity (STP), a typical synaptic behavior, is observed when stimulating the device with input spikes of 1 volt. Both significant facilitating and depressing behaviors of this artificial synapse are observed with a relative amplitude of about 50% and a dynamic response < 200 ms. From a series of in-situ experiments, i.e. measuring the current-voltage characteristic curves in-situ and in real time, during the growth of the pentacene over a network of gold nanoparticles, we elucidate these results by analyzing the relationship between the organic film morphology and the transport properties. This synapstor works at a low energy of about 2 nJ/spike. We discuss the implications of these results for the development of neuro-inspired computing architectures and interfacing with biological neurons., Comment: Full paper with supporting information

A light-emitting OFET with pronounced ambipolar current characteristic has been prepared by co-evaporation of α-quinquethiophene (α-5T) as hole-transport material and ditridecyl-perylene-tetracarboxylic diimide (P13) as electron-transport material. The light intensity is controlled by both the drain-source voltage VDS and the gate voltage VG. Here, we demonstrate the general concept of adjusting electron and hole mobilities by co-evaporation of two different organic semiconductors.