The electronic structure of Ti2 and Ti2(+)

The Ti(2) and Ti(2)(+) molecular systems have been studied through multireference variational and single reference coupled-cluster methods coupled with large basis sets. Potential energy curves have been constructed for 30 (Ti(2)) and 2 (Ti(2)(+)) states and the usual spectroscopic parameters have been extracted. The main feature of the potential curves is the existence of van der Waals minima (Ti(2)) around 7 bohr irrespective of the molecular symmetry, and 4s(2)-4s(1) interactions (Ti(2)(+)) around 6 bohr. Numerous avoided crossings lead to stronger covalent bonds emanating from 4s(1)-4s(1) atomic distributions. The X-state of the neutral species is formally a (3)Δ(g) state with the first excited state lying within 1 kcal/mol. The removal of the symmetry defining e(-) leads to the X(2)Σ(g)(+) state of Ti(2)(+).     

Oxide thickness and roughness factor as parameters for TiO<Subscript>2</Subscript>-dye sensitized solar cells performance

Oxide surface roughness in connection to oxide thickness has proved to be a key parameter for the performance of a dye sensitised solar cell. In this work, the numerical simulation of the system TiO₂-photo sensitive dye of a dye sensitized TiO₂ solar cell focuses on these two parameters. The steady-state numerical model used is based on the continuity and transport equations for charge species involved in the system, in connection to Poisson’s equation. Light absorbance is set dependent upon TiO₂ porosity and resulting electron density after illumination is derived as a function of the illuminating beam characteristics and material properties. Electron lifetime in the bulk is set dependent upon electron distribution with electron lifetime at the surface taking into consideration surface recombination. An effective dielectric constant dependent also upon the porosity of TiO₂ is used in the model. Results for different values of the TiO₂ thickness and surface roughness leading to optimum values for the cell performance are found in accordance with results reported in the literature.     

Delayed Capital Injections for a Risk Process with Markovian Arrivals

Methodology and Computing in Applied Probability - In this paper we propose a generalisation to the Markov Arrival Process (MAP) risk model, by allowing for a delayed receipt of required capital...     

Optimum oxide thickness for dye-sensitized solar cells—effect of porosity and porous size. A numerical approach

The microstructure of the metal semiconductor oxide which forms the heart of a dye-sensitized solar cell (DSSC) has proved to play a key role in the enhancement of photoelectric conversion efficiency of the cell. In this work, a numerical simulation of the system TiO₂ photo-sensitive dye of a TiO₂ DSSC focuses on the effect that the oxide porosity and the size of the pores have on the cell's performance. The steady-state numerical model used is based on the continuity and transport equations for charge species involved in the system, in connection to Poisson's equation. Light absorption coefficient is set dependent on both porosity and the size of pores in TiO₂. At a first approximation, electron mobility is considered dependent upon porosity following an iteration procedure dependent also upon local field in the oxide. An effective dielectric constant dependent upon the porosity of TiO₂, as well, is used in the model. Electron lifetime in the bulk is set dependent upon electron distribution following the iteration procedure with electron lifetime at the surface taking into consideration surface recombination. Results for different values of TiO₂ porosity and pores' size in connection to the oxide thickness are discussed and found in accordance with results reported in the literature.     

C?C Bond Formation via Carbon-Centered Radicals Generated from Dicarbonyl(η5-cyclopentadienyl) organoiron Complexes

Irradiation of benzyldicarbonyl(η⁵-cyclopentadienyl)iron complex ( 2 ) leads to hemolytic cleavage of the Fe? C bond. In the presence of activated alkenes, radical addition occurs and both saturated and unsaturated addition products 7–9 are formed. Photolysis of alkyliron complexes 2 , 3 and 20 in the presence of acrylonitrile leads to the same products as the irradiation of the respective acyliron complexes 28–30 . This indicates that, under photolytical conditions, alkyl and acyl complexes are in equilibrium with each other.     

Über positiv-definite Klassenfunktionen abzählbarer Gruppen

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Über imprimitive Darstellungen lokal-kompakter Gruppen

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