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Fourier transform visible spectroscopy, in conjunction with VUV photons produced by a synchrotron, is employed to investigate the photodissociation of CH3CN. Emission is observed from both the CN(B2Sigma+ - X2Sigma+) and CH(A2Delta - X2PI) transitions; only the former is observed in spectra recorded at 10.2 and 11.5 eV, whereas both are detected in the 16 eV spectrum. The rotational and vibrational temperatures of both the CN(B2Sigma+) and CH(A2Delta) radical products are derived using a combination of spectral simulations and Boltzmann plots. The CN(B2Sigma+) fragment displays a bimodal rotational distribution in all cases. Trot(CN(B2Sigma+)) ranges from 375 to 600 K at lower K' and from 1840 to 7700 K at higher K' depending on the photon energy used. Surprisal analyses indicate clear bimodal rotational distributions, suggesting CN(B2Sigma+) is formed via either linear or bent transition states, respectively, depending on the extent of rotational excitation in this fragment. CH(A2Delta) has a single rotational distribution when produced at 16 eV which results in Trot(CH(A2Delta)) = 4895 +- 140 K in nu' = 0 and 2590 +- 110 K in nu' = 1. From thermodynamic calculations, it is evident that CH(A2Delta) is produced along with CN(X2Sigma+) + H2. These products can be formed by a two step mechanism (via excited CH3* and ground state CN(X2Sigma+) or a process similar to the "roaming" atom mechanism; the data obtained here are insufficient to definitively conclude whether either pathway occurs. A comparison of the CH(A2Delta) and CN(B2Sigma+) rotational distributions produced by 16 eV photons allows the ratio between the two excited fragments at this energy to be determined. An expression that considers the rovibrational populations of both band systems results in a CH(A2Delta):CN(B2Sigma+) ratio of (1.2 +- 0.1):1 at 16 eV, thereby indicating that production of CH(A2Delta) is significant at 16 eV.

Fourier transform visible emission spectroscopy is used to investigate the reaction [C.sub.2]H + [O.sub.2] a CH([A.sup.2][DELTA]) + C[O.sub.2]. The rotational excitation has indicated a bent geometry for the final intermediate of this reaction before dissociation to products and the vibrational excitation has involved an elongation of the C-H bond from the compressed transition state to the final CH(A) state.

An investigation is done on the reaction C(sub 2) H + O((super 3)P) giving CH(A) + CO using Fourier transform visible (FTVIS) emission spectroscopy. It is concluded that CH(A) florescence is a suitable probe to obtain detailed information about the state-resolved dynamics of the C(sub 2)H + O((super 3)P) reaction using FTVIS spectroscopy and C(sub 2)H + O((super 3)P) reaction may play important role in low-pressure C(sub 2)H(sub 2)/O/H flames.

The C(super 2)H + O[(super 3)P] reaction is investigated using time-resolved Fourier transform infrared spectroscopy. The time dependencies of the CO and CO2 species are measured experimentally and simulated to determine conditions under which contributions from the several processes that give the same product can be differentiated.

Abstract Background There is renewed interest in magnetic hyperthermia as a treatment modality for cancer, especially when it is combined with other more traditional therapeutic approaches, such as the co-delivery of anticancer drugs or photodynamic therapy. Methods The influence of bimagnetic nanoparticles (MNPs) combined with short external alternating magnetic field (AMF) exposure on the growth of subcutaneous mouse melanomas (B16-F10) was evaluated. Bimagnetic Fe/Fe3O4 core/shell nanoparticles were designed for cancer targeting after intratumoral or intravenous administration. Their inorganic center was protected against rapid biocorrosion by organic dopamine-oligoethylene glycol ligands. TCPP (4-tetracarboxyphenyl porphyrin) units were attached to the dopamine-oligoethylene glycol ligands. Results The magnetic hyperthermia results obtained after intratumoral injection indicated that micromolar concentrations of iron given within the modified core-shell Fe/Fe3O4 nanoparticles caused a significant anti-tumor effect on murine B16-F10 melanoma with three short 10-minute AMF exposures. We also observed a decrease in tumor size after intravenous administration of the MNPs followed by three consecutive days of AMF exposure 24 hrs after the MNPs injection. Conclusions These results indicate that intratumoral administration of surface modified MNPs can attenuate mouse melanoma after AMF exposure. Moreover, we have found that after intravenous administration of micromolar concentrations, these MNPs are capable of causing an anti-tumor effect in a mouse melanoma model after only a short AMF exposure time. This is a clear improvement to state of the art.

Understanding plasmonic enhancement of nanoscale magnetic materials is important to evaluate their potential for application. In this study, the Faraday rotation (FR) enhancement of gold coated Fe2O3 nanoparticles (NP) is investigated experimentally and theoretically. The experiment shows that the Faraday rotation of a Fe2O3 NP solution changes from approximately 3 rad/Tm to 10 rad/Tm as 5 nm gold shell is coated on a 9.7 nm Fe2O3 core at 632 nm. The results also show how the volume fraction normalized Faraday rotation varies with the gold shell thickness. From the comparison of experiment and calculated Faraday rotation based on the Maxwell-Garnett theory, it is concluded that the enhancement and shell dependence of Faraday rotation of Fe2O3 NPs is a result of the shifting plasmon resonance of the composite NP. In addition, the clustering of the NPs induces a different phase lag on the Faraday signal, which suggests that the collective response of the magnetic NP aggregates needs to be considered even in solution. From the Faraday phase lag, the estimated time of the full alignment of the magnetic spins of bare (cluster size 160 nm) and gold coated NPs (cluster size 90 nm) are found to be 0.65 and 0.17 μs. The calculation includes a simple theoretical approach based on the Bruggeman theory to account for the aggregation and its effect on the Faraday rotation. The Bruggeman model provides a qualitatively better agreement with the experimentally observed Faraday rotation and points out the importance of making a connection between component properties and the average 'effective' optical behavior of the Faraday medium containing magnetic nanoparticles. [ABSTRACT FROM AUTHOR]

The photo dissociation dynamics of bromoform is investigated using Fourier transform visible fluorescence spectroscopy (FTVIS) in the 10-20 eV excitation energy range through the analysis of the internal state distributions of the CH(A) fragment. The analysis of the CH(A) rotational populations has shown hotter rotational populations for the femtosecond experiment, also indicating sequential dissociation of the bromoform in the femtosecond experiment.

C2H2 + O[(super 3)P] and HCCO + O[(super 3)P] reactions are investigated using Fourier transform infrared (FTIR) emission spectroscopy. The result showed that the bimodal CO(epsilon) distribution for the HCCO + O[(super 3)P] reaction suggests a sequential dissociation process.