The circular dichroism (CD) spectrum of polyproline I1 (PPII) has heretofore been moderately well calculated from exciton theory only at the expense of assuming unreasonable chain conformations and accepting a conservative spectrum in the 180250-nm region (which is not observed). We have incorporated far uv transitions in the polarisability approximation and, together with the r2r* transition, ...

The asymptotic behavior of the optical potential, describing elastic scattering of a charged particle α off a bound state of two charged, or one charged and one neutral, particles at small momentum transfer ∆ α or equivalently at large intercluster distance ρ α , is investigated within the framework of the exact three-body theory. For the three-charged-particle Green function that occurs in the...

The molecular polarisability and hyperpolarisability tensors of a group of donoracceptor polyene molecules are calculated using the time dependent Hartree-Fock code implemented in the MOPAC quantum chemistry program. The results agree with other theoretical and experimental calculations. The values obtained are then used to investigate mutual polarisation of collections of such molecules, e.g. ...

As reported in the literature, several factors, such as scattering cross sections, polarisability and wavelength suitability, contribute to increased SERS enhancement. In general, the advantage of surface-enhanced Raman scattering (SERS)-active Ag nanoparticles (NPs) is their higher SERS enhancement over Au NPs because the molar extinction coefficient of the Ag NPs is the highest of its kind am...

Benzaldehydes are components of atmospheric aerosol that poorly represented in current vapour pressure predictive techniques. In this study the solid state (PSsat) and sub-cooled liquid saturation pressures (PLsat) were measured over a range temperatures (298–328 K) for chemically diverse group benzaldehydes. The selected benzaldehydes allowed effects varied geometric isomers functionalities on...

Reactions in scCO2 are frequently limited by the low polarity of the solvent. This may result in low solute/ product solubility or low catalyst activity. The use of more polar sc fluids such as difluoromethane (HFC 32) can circumvent many of these issues and facilitate reactions that are not possible in CO2. We demonstrate the use of HFC 32 for three types of reaction; an esterification reactio...

Whereas human red blood cells and protoplasts of leaves of Avena sativa show rotation only at discrete frequencies in the kHz-range of a linear alternating electric field, rotation of these cells is observed at practically every frequency in the MHz range (15 to 200 MHz). The cell rotation in the MHz-range can be explained in terms of field induced polarisation and orientation of permanent dipo...

The static mean polarisabilities a and polarisability anisotropies Da of nine molecules have been computed at the B3LYP level by using 6-31111G(3df,2pd), aug-cc-pVDZ and Sadlej basis sets, experimental re or optimised geometries. These molecules are either linear (CO2, CS2, OCS, HCCH) or symmetric top (CH3CCH, CH3Cl, CHCl3, CH3CN, C6H6). A statistical comparison with accurate experimental data ...

32 Driving the interconnect dimensions of microelectronic circuits to smaller sizes, the delay time caused by the electrical resistance of the Aluminium or Copper wires and the capacitors generated by neighbouring wires and the insulating material becomes the essential limiting factor of the performance of the circuits [1-3]. Fig. 1 shows the delay time as a function of the interconnect dimensi...