Search results for "version"
showing 10 items of 1591 documents
Adenine and 2-aminopurine: Paradigms of modern theoretical photochemistry
2006
Distinct photophysical behavior of nucleobase adenine and its constitutional isomer, 2-aminopurine, has been studied by using quantum chemical methods, in particular an accurate ab initio multiconfigurational second-order perturbation theory. After light irradiation, the efficient, ultrafast energy dissipation observed for nonfluorescent 9H-adenine is explained here by the nonradiative internal conversion process taking place along a barrierless reaction path from the initially populated 1 (ππ* L a ) excited state toward a low-lying conical intersection (CI) connected with the ground state. In contrast, the strong fluorescence recorded for 2-aminopurine at 4.0 eV with large decay lifetime …
Energy transfer in diiodoBodipy-grafted upconversion nanohybrids.
2015
Steady-state and time-resolved emission studies on nanohybrids consisting of NaYF4:Yb,Er and a diiodo-substituted Bodipy (UCNP-IBDP) show that the Yb(3+) metastable state, formed after absorption of a near-infrared (NIR) photon, can decay via two competitive energy transfer processes: sensitization of IBDP after absorption of a second NIR photon and population of Er(3+) excited states.
On the role of the triplet state in the cis/trans isomerization of rhodopsin: A CASPT2//CASSCF study of a model chromophore
2011
The possibility of population of the lowest-lying triplet state (T1) in the early events of the photochemical isomerization process of a model chromophore of Rhodopsin (Rh) has been analyzed using multireference perturbation theory (CASPT2//CASSCF) methods. It is shown that the characteristics of the isomerization process namely small S1−T1 gap, presence of hydrogen out of plane active vibrational modes, and existence of a dense manifold of vibrational states, render possible the fulfilment of the conditions needed for the population of T1. The possible consequences for the photochemistry and photophysics of Rh are also discussed. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111:3431–3…
Development of sustainable ORC applications in the tertiary sector: a case study in the Mediterranean climate
2022
Abstract In recent decades, climate change strong advancement has led many countries, especially the most developed ones, to a greater sense of environmental responsibility. On a global, European and national level, adaptation/mitigation strategies and actions aimed at improving energy-environmental sustainability and resilience in the tertiary sectors have been increasingly intensified. In this sector, therefore, plays a fundamental role the integration/introduction of technologies able to operate an efficient conversion of energy, such as indeed Organic Rankine Cycle (ORC) plant, other than renewable energy sources, in order to reduce both energy consumption and pollutant emissions. Withi…
Electrochemical conversion of Carbon Dioxide: effect of operating parameters and of the reactor on the performances of the process.
2017
Determination of absolute internal conversion coefficients using the SAGE spectrometer
2016
A non-reference based method to determine internal conversion coefficients using the SAGE spectrometer is carried out for transitions in the nuclei of 154Sm, 152Sm and 166Yb. The Normalised-Peak-to-Gamma method is in general an efficient tool to extract internal conversion coefficients. However, in many cases the required well-known reference transitions are not available. The data analysis steps required to determine absolute internal conversion coefficients with the SAGE spectrometer are presented. In addition, several background suppression methods are introduced and an example of how ancillary detectors can be used to select specific reaction products is given. The results obtained for …
The Emotion Regulation Cecklist Italian Translation Validation for parents and teacher versions.
2014
Our research explored the factor structure and the reliability of the Italian version of the Emotion Regulation Checklist [ERC; Shields, A.,& Cicchetti, D. (1997). Emotion regulation among school-age children: The development and validation of a new criterion Q-sort scale. Developmental Psychology, 33, 906-916], an instrument that has been widely adopted in studies using parents and/or teachers as informants. We carried out two studies evaluating the properties of the Italian ERC (ERC-I) when completed by parents and teachers, respectively. Study 1 participants were kindergarten and elementary school children for whom the ERC was completed by their mothers. Study 2 involved kindergarten and…
Efficient Conversion of Light to Chemical Energy : Directional, Chiral Photoswitches with Very High Quantum Yields
2020
Abstract Photochromic systems have been used to achieve a number of engineering functions such as light energy conversion, molecular motors, pumps, actuators, and sensors. Key to practical applications is a high efficiency in the conversion of light to chemical energy, a rigid structure for the transmission of force to the environment, and directed motion during isomerization. We present a novel type of photochromic system (diindane diazocines) that converts visible light with an efficiency of 18 % to chemical energy. Quantum yields are exceptionally high with >70 % for the cis–trans isomerization and 90 % for the back‐reaction and thus higher than the biochemical system rhodopsin (64 %). T…
Hybrid Energy Storage Modeling And Innovative Solutions For Energy Storage Management Systems
2022
La presente tesi riguarda la modellazione di diverse fonti di accumulo di energia elettrica, in particolare batterie e supercondensatori (SC), e di nuove configurazioni di metodi di gestione di sistemi di accumulo di energia ibridi . Il crescente bisogno di domanda di energia e il desiderio di raggiungere uno sviluppo sostenibile, si riflettono nell'uso di Generatori Distribuiti (DG) basati sulle Fonti energetiche Rinnovabili (FER). L'uso di un controllo di supervisione intelligente e il raggruppamento locale della domanda e della generazione possono portare a notevoli miglioramenti nell'efficienza, affidabilità e resilienza del sistema elettrico. Il problema principale della DG basata sull…
Up-conversion and Photoluminescence in Er3+ Single Crystal MgAl-spinel
2015
Abstract Traditional and up-conversion luminescence of MgAl 2 O 4 single crystal doped with erbium ions obtained by the Verneuil method has been investigated. The time resolved spectral measurements of the green and red up-conversion luminescence bands show that a build-up part is present in the up-conversion luminescence kinetics. This means that energy transfer process is involved in the creation of the luminescence. Considering rather small concentration of Er 3+ in the material (0.12 mass %), the expected up-conversion mechanism should be excited state absorption since the average distance between erbium ions is high. The above-mentioned considerations suggest that clustering of the act…