Search results for "Raman Spectroscopy"
showing 10 items of 1007 documents
Collisional Relaxation Processes Studied by Coherent Raman Spectroscopy for Major Species Present in Combustions
1992
The effects of collisional relaxation processes on the Q-branch profile of major species present in combustions have been studied by high resolution stimulated Raman spectroscopy. Particular interest has focused on the following collisional systems: N2-N2, O2-O2, CO2-CO2, O2-N2, N2-CO2 and N2-H2O. For each colliding pair, starting from accurate determinations of line broadening coefficients over a wide temperature range, state-to-state rates for rotational energy transfers have been deduced by using various fitting laws. Among these rate laws, special attention has been paid to the temperature dependence of the energy corrected scaling (ECS) law combined with a hybrid exponential-power law …
Improvement of Raman Spectra of SAPO-5 by Chromium(III)-Induced Luminescence Quenching
1995
Impulsive excitation of high vibrational states in I2–Xe complex on the electronic ground state
2010
Abstract High vibrational states, up to ν = 22, are excited and investigated on the ground electronic state of a 1:1 I 2 –Xe complex isolated in solid Kr using femtosecond CARS technique and spontaneous resonant Raman measurements. The results show that this system is a promising candidate for investigations of coherent control of bimolecular reactions by using vibrational wavepackets on the ground electronic state.
On the biradicaloid nature of long quinoidal oligothiophenes: experimental evidence guided by theoretical studies.
2007
Raman measurements in the intermediate phase of [N(CH3)4]2ZnI4
1991
Abstract Raman spectra and deviation angle of the indicatrix have been measured in the intermediate phase, between the two transition temperatures T c1 = 255 K and T c2 = 217 K. The results are consistent with the existence, in this phase, of large domains, piled up along the c-axis (Pnma notation).
Structure and Photocatalytic Properties of TiO2-WO3Composites Prepared by Electrophoretic Deposition
2015
In this work TiO2-WO3 composite films containing different oxide concentrations were prepared by electrophoretic deposition on steel substrates. Composite coating structures were analyzed by X -ray diffraction, Raman spectra and scanning electron microscopy. The results showed an even distribution of WO3 particles in the entire composite layer. Light absorption measurements were used for photocatalytic properties evaluation. It was found that the removal ratio of methylene blue depends on the (TiO2):(WO3) concentration ratio. The most effective photodegradation was determined for the sample that was electrophoretically deposited from the suspension with the molar content ratio n(TiO2):n(WO3…
Optimisation algorithms in the case of mineral detection using Raman Analysis
2013
Abstract Raman analysis can be used to analyse the existence of minerals in an ore sample. Especially the interest here is to analyse given ore sample rapidly, to find out what minerals it contains. Rapid analysis would enable more rapid exploration of minerals as analysis could be carried out on-site. For this study, ore samples were collected from two mines in Northern Finland, Kittila and Kevitsa. An optimisation algorithm was constructed to form a linear combination of reference spectra which best represent the measured spectrum from an ore sample. The reference spectra were collected from a public source. It was found that solving for an optimal summation of reference spectra can be a …
Methods for the vibrational spectroscopy analysis of beers
2009
The main possibilities and drawbacks of vibrational spectroscopy techniques, infrared (both in the middle and near infrared ranges) and Raman, for the analysis of beers have been reviewed taking into consideration methods proposed in the scientific literature for the determination of as many as possible compounds and parameters of beers. Details about the procedures available and comments on the future developments in this field have been based on the experience of authors and extended checking of the characteristics of the procedures published till now.
High Resolution Coherent Anti-Stokes Raman Spectroscopy (CARS) Of O 2 And CO 2
1988
With the help of high spectral quality (linewidth , 6 MHz) injection-locked flashlamp-pumped dye lasers, high resolution Coherent Anti-Stokes Raman Spectroscopy (CARS) has been applied to the study of the Q-branches of 0 2 and CO 2 . The Q-branch linewidths of 02 were obtained from the first nine transitions (J 2 = 1 to 17) recorded at pressures from 0.094 to 1 atm at room temperature. A least squares program was employed to fit calculated spectra to experimental spectra by adjusting different parameters. The collisional broadening coefficients we have obtained are consistent with available Raman data. We have also studied the Q-branch of the fundamental v1 band of CO 2 in the Fermi resonan…