Density Functional Calculation of the Photoelectron Emission Spectra of BiSCl Crystal and Molecular Clusters

The photoelectron emission spectra of BiSCl crystal and molecular clusters have been calculated by the Density Functional Theory (DFT) method. Molecular clusters consists from 2 to 20 molecules in one double chain along z(c) axis. Total and partial density of states of BiSCl crystal and clusters have been weighted with atomic photoemission emission cross-section. The molecular clusters have been investigated including all normal modes of vibration. Theoretical results of BiSCl crystal and molecular clusters have been compared with experimental X-ray photoelectron emission spectra (XPS) of BiSI crystal.     

Permeability of acetic acid through organic films at the air-aqueous interface

Recent field studies of collected aerosol particles, both marine and continental, show that the outermost layers contain long-chain (C >or= 18) organics. The presence of these long-chain organics could impede the transport of gases and other volatile species across the interface. This could effect the particle's composition, lifetime, and heterogeneous chemistry. In this study, the uptake rate of acetic acid vapor across a clean interface and through films of long-chain organics into an aqueous subphase solution containing an acid-base indicator (bromocresol green) was measured under ambient conditions using visible absorption spectroscopy. Acetic acid is a volatile organic compound (VOC) and is an atmospherically relevant organic acid. The uptake of acetic acid through single-component organic films of 1-octadecanol (C(18)H(38)O), 1-triacontanol (C(30)H(62)O), cis-9-octadecen-1-ol (C(18)H(36)O), and nonacosane (C(29)H(60)) in addition to two mixed films containing equimolar 1-triacontanol/nonacosane and equimolar 1-triacontanol/cis-9-octadecen-1-ol was determined. These species represent long-chain organic compounds that reside at the air-aqueous interface of atmospheric aerosols. The cis-9-octadecen-1-ol film had little effect on the net uptake rate of acetic acid vapor into solution; however, the uptake rate was reduced by almost one-half by an interfacial film of 1-triacontanol. The measured uptake rates were used to calculate the permeability of acetic acid through the various films which ranged from 1.5 x 10(-3) cm s(-1) for 1-triacontanol, the least permeable film, to 2.5 x 10(-2) cm s(-1) for cis-9-octadecen-1-ol, the most permeable film. Both mixed films had permeabilities that were between that of the single-component films comprising the mixture. This shows that the permeability of a mixed film may not be solely determined by the most permeable species in the mixture. The permeabilities of all the films studied here are discussed in relation to their molecular properties, pressure-area isotherms, and atmospheric implications.     

Quantification of the evolution of shape storage and recovery in thermally responsive shape memory polymers

This study demonstrates the relevance of strain and stress storage/recovery profiles for the thermomechanical behaviour of thermally responsive Shape Memory Polymers (SMPs). It is shown how these experimentally determined profiles may be used for the development, calibration and validation of continuum-based models describing the shape memory effect in polymeric materials. The presented methodology applies both to small and finite strain deformation problems under the assumption of constant strain and cooling/heating rates. (© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

On the geometry of Kawaguchi spaces

In the paper, with the use of the E. Cartan exterior forms method, the theory of linear and affine connections of the generalized Kawaguchi space of order two is constructed. It is proved that the linear connection of this space incorporates intrinsic antiquaternional structures, the conditions of their complete integrability are found, and the affine connections associated with the above-mentioned structures are constructed. Translated from Lietuvos Matematikos Rinkinys, Vol. 40, No. 3, pp. 321–334, July–September, 2000. Translated by R. Lapinskas     

Ultrafast nuclear dynamics induced by photodetachment of Ag2- and Ag2O2-: oxygen desorption from a molecular silver surface

Femtosecond nuclear dynamics of mass-selected neutral Ag2 and Ag2O2 clusters are investigated with the 'negative ion-to neutral-to positive ion'(NeNePo) technique. For the bare silver dimer, wave packet dynamics occurring in the neutral electronic ground state and in the first excited triplet state are observed after photodetachment from the anion with 3.05 eV photon energy. While the dynamics in the ground state lead to an oscillatory structure in the NeNePo-pump-probe spectra with a vibrational constant of 185 cm-1, the dynamics in the triplet state are assigned to a bound-free transition leading to dissociation. Photodetachment from the Ag2O2- complex results in the desorption of O2. The experimental data clearly show the influence of the desorbing oxygen ligand on the nuclear dynamics of the silver dimer inducing a red shift in the vibrational frequency and an intensity enhancement of the oscillatory signal.