Subpicosecond photoinduced Stark spectroscopy in fullerene-based devices

Published versio

La construcción de la agenda de los medios. El debate del estatut en la prensa española

El estudio de las agendas de los medios se ha basado fundamentalmente en los efectos que éstas tienen sobre la audiencia, aplicando la teoría de la Agenda Setting. Sin embargo, para calibrar estas influencias es interesante conocer cómo se configuran las agendas, y profundizar en el proceso de Agenda Building. En este artículo se explora el modo de construcción de la agenda en el caso del debate sobre el Estatut en el Parlamento español, siguiendo un modelo de procesos que atiende a tres criterios conformadores de la agenda: la selección de la noticia, quién accede a los medios y con qué enfoques o frames lo hace. A través de un análisis de contenido de siete diarios, las conclusiones ayudan a comprender los tipos de cobertura aplicados, las diferencias entre periódicos y los procesos de creación de las agendas

Simulation of the response of a silicon pixel detector

A model to simulate the response of a silicon pixel detector is described. The effects of geometrical charge sharing, electronic noise threshold dispersion, capacitive coupling between pixel channels and d -rays production have been taken into account. The model has been tested on the Omega3chip, which is the direct predecessor of the ALICE pixel detector, to be used in the inner tracking system of the ALICE experiment. The model is able to reproduce the experimental data and the resulting parameters are consistent with the measurements made on the Omega3chip. Key words:silicon pixel, simulation PACS:07.05.T,29.40.

The pixel detector based tracklet reconstruction algorithm in ALICE

This note describes a method to reconstruct signals in the two silicon pixel detector layers compatible with tracks coming from the main interaction vertex, namely tracklets. The basic algorithm strategy and its performance are illustrated

Long-living optical gain induced by solvent viscosity in a push-pull molecule

The combination of continuum and ultrafast pump-probe spectroscopy with DFT and TDDFT calculations, in viscous and non-viscous environments, is effective in unraveling important features of the twisted intramolecular charge transfer mechanism in a new push-pull molecule that possesses aggregation induced emission properties. Long-living optical gain is found when this mechanism is inhibited, highlighting the importance of the environment rigidity in the design of materials for photonic applications

Deep blue light amplification from a novel triphenylamine functionalized fluorene thin film

The development of high performance optically pumped organic lasers operating in the deep blue still remains a big challenge. In this paper, we have investigated the photophysics and the optical gain characteristics of a novel fluorene oligomer functionalized by four triphenylamine (TPA) groups. By ultrafast spectroscopy we found a large gain spectral region from 420 to 500 nm with a maximum gain cross-section of 1.5 × 10-16 cm2 which makes this molecule a good candidate for photonic applications. Amplified Spontaneous Emission measurements (ASE) under 150 fs and 3 ns pump pulses have revealed a narrow emission at 450 nm with a threshold of 5.5 μJcm-2 and 21 μJcm-2 respectively. Our results evidence that this new fluorene molecule is an interesting material for photonic applications, indeed the inclusion of TPA as a lateral substituent leads to a high gain and consequently to a low threshold blue organic ASE

Study of a New Trigger on Multiplicity and Primary Interaction Vertex using the ALICE Silicon Pixel Detector

New trigger inputs for the ALICE Central Trigger Processor (CTP) are proposed. They are based on the use of Fast Multiplicity (FM) output signals generated by the ALICE Silicon Pixel Detector (SPD). These can be used for a multiplicity based centrality trigger and for a fast on-line computation of the primary vertex. A simple algorithm for primary vertex location at the trigger level is proposed. The precision that can be achieved with this method on centrality selection and primary vertex location, is discussed for interactions with different pseudo-rapidity density level. The feasibility of background rejection is also considered

Photoinduced transient stark spectroscopy in organic semiconductors: a method for charge mobility determination in the picosecond regime.

Published versio