The exciton scattering (ES) approach attributes excited electronic states in quasi-1D branched polymer molecules to standing waves of quantum quasiparticles (excitons) scattered at the molecular vertices. We extract their dispersion and frequency-dependent scattering matrices at termini, ortho, and meta joints for pi-conjugated phenylacetylene-based molecules from atomistic time-dependent densi...

The calculation of the vibrational structure associated to electronic spectra in large molecules requires a Taylor expansion of the initial and final state potential energy surface (PES) around some reference nuclear structure. Vertical (V) and adiabatic (A) approaches expand the final state PES around the initial-state (V) or final-state (A) equilibrium structure. Simplest models only take int...

Excited-state geometries and electronic spectra of butadiene, acrolein, and glyoxal have been investigated by the symmetry adapted cluster configuration interaction (SAC-CI) method in their s-trans conformation. Valence and Rydberg states below the ionization threshold have been precisely calculated with sufficiently flexible basis sets. Vertical and adiabatic excitation energies were well repr...

Highly accurate excitation spectra are predicted for the low-lying n-π* and π-π* states of uracil for both the gas phase and in water employing the complete active space self-consistent field (CASSCF) and multiconfigurational quasidegenerate perturbation theory (MCQDPT) methods. Implementation of the effective fragment potential (EFP) solvent method with CASSCF and MCQDPT enables the prediction...

Audio-rate modulation of the parameters of physical models is investigated. For example, the resonance frequency of a simple resonator can be modulated smoothly at an audio rate to produce a brighter tone. As with traditional frequency modulation (FM) signal models, complex spectra can be produced through variation of the resonator’s frequency. It is possible to create such hybrid physical/sign...

sour orange is one of native fruits of iran, which are widely used in the food industry, medicine and cosmetics. sour orange peel is rich source of pectin and generally discarded as waste. in this research, response surface methodology (rsm) with box–behnken design was employed to optimize and to study the effects of the independent variables (temperature, time and ph) on the yield of pectin an...

Single-wall carbon nanotubes can be probed optically by elastic light scattering. This effect forms the basis of a technique, termed Rayleigh scattering spectroscopy, for the study of individual nanotubes. Spectroscopic information on the electronic transitions of both semiconducting and metallic nanotubes is obtained by measuring the elastic scattering cross section as a function of photon ene...

There have been many productive methods developed so far for optimization of multiple response surface (MRS) problems. This paper tends to review the most seminal approaches in MRS and discuss the strength and weakness of each of the approaches through existing aspects in MRS. A numerical example is included to compare results by different methods. Finally some of the prominent areas for future...

Abstract In this paper, the dynamical similarity of multi-block catenary arches and columns is discussed, which can be used for simplified design rocking arches. The basic hypothesis that dynamic response similar when shape arch follows thrust line, i.e. it a arch. It validated numerically responses slender are safe reliable approximations those not then overturning acceleration (response) spec...