Reports of Intergovernmental Panel on Climate Change raised the issue of adaptation to impacts caused by climate change. Mitigation efforts appeared difficult and their effects are delayed. In this respect adaptation is required as it helps to reduce losses and adjust economies to actual challenges. In the paper the concept of adaptation is reviewed and related terms such as vulnerability and adaptive capacity are introduced. Typologies of adaptation are presented as well as the institutional dimension of the efforts. Further, several examples of adaptation options are described, with emphasis on the role of policies. Also difficulties in the introduction of the adaptation options are discussed. Finally, the issue of adaptation assessment is raised. It is argued that difficulties with precise assessment of adaptation costs and benefits are to a certain extent unavoidable. This constitutes, however, one of the constraints to successful adaptation.
The ONIOM(B3PW91:HF) hybrid method has been evaluated for the purposes of modeling butyltin chlorides, XnSnCl4-n (X = n-butyl, sec-butyl, isobutyl, tert-butyl; n = 1, 2, 3). Three different partitioning schemes of a molecule within ONIOM(B3PW91:HF) were taken into account. For each of these partitioning schemes, conformational analyses of the XnSnCl4-n molecules were performed and then several molecular properties of the resulting rotamers were calculated. The values of molecular properties obtained by ONIOM(B3PW91:HF) were compared in a statistical manner with the reference values calculated by B3PW91. A careful choice of partitioning scheme for XnSnCl4-n allowed ONIOM(B3PW91:HF) to achieve a significant saving in computational cost, together with a relatively small decrease in the accuracy of the XnSnCl4-n molecular properties routinely obtained from conformational analysis (structural parameters, etc.). Unfortunately, the hybrid method turned out to be ineffective in reproducing the 1H, 13C and 119Sn NMR chemical shifts in XnSnCl4-n accurately. [...]
The effect of alloying on the adsorption of atomic hydrogen was studied using density functional theory (DFT). In the study the (100) surfaces of Pd-Ag, Pd-Pt, Pd-Au, Pt-Ag, and Pt-Au alloys were considered by means of a cluster model. The structural and energetic properties of the H atom adsorbed on the Pd4Me (Me = Ag, Pt, Au) and Pt4Me (Me = Pd, Ag, Au) clusters were calculated and compared with the H-atom adsorption on monometallic clusters. The effect of alloying on the H-atom adsorption is evident for all the investigated bimetallic systems. However, it strongly depends on the second metal atom, Me, is placed in the surface layer or in the subsurface one. In general, the H atom adsorbed in a site containing the second metal exhibits different properties from those characteristic of its adsorption on Pd(100) and Pt(100). Hence, the modified interaction between atomic hydrogen and the alloyed surfaces may increase the selectivity of the catalytic hydrogenation reactions on such surfaces.
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