Neste trabalho foram analisadas amostras de matéria orgânica de solos (MOS) de área de floresta nativa (SFN) e de solos de uma área vizinha, local de mineração de xisto, que vem sendo reabilitada há 30 anos (SFR). As espectroscopias de ressonância paramagnética eletrônica (RPE, banda X) e ressonância magnética nuclear (RMN) de 13C com as amostras no estado sólido foram utilizadas para avaliar a recuperação do solo reabilitado após a mineração do xisto. Estudos de correlação heteroespectral bidimensional dos resultados obtidos por RPE e RMN 13C foram utilizados para obter informações sobre a estrutura da matéria orgânica do solo e suas interações com o oxicátion paramagnético residual VO2+. As estruturas orgânicas hidrofílicas, que correlacionaram positivamente com o oxicátion metálico VO2+, são do tipo ácido urônico, determinadas por RMN 13C, e negativamente com o sinal do radical livre orgânico (RLO) associado a átomos de oxigênio (g = 2,0042). As estruturas hidrofóbicas aromáticas se correlacionaram positivamente com o sinal de RPE do RLO associado a átomos de carbono (g = 2,0022). Os dados das duas técnicas espectroscópicas magnéticas aplicadas às amostras de ambos os solos (SFN e SFR) mostram que o processo usado na recuperação dos solos de mineração vem sendo efetivo.

In this work, native forest soil (NFS) organic matter (SOM) sample and SOM samples from a neighboring forest soil area of an oil shale mine which is being rehabilitated for thirty years (RFS) were analyzed. X-band electron paramagnetic resonance (EPR) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopies were used to evaluate the soil reclamation of the Brazilian oil shale mining process. Two-dimensional heterospectral correlation studies of the results obtained from EPR and 13C NMR were used to obtain information about SOM structures and their interactions with residual paramagnetic metal ion. The signal of the residual metallic oxycation, VO2+ correlated positively with uronic acid-type hydrophilic organic structures, determined from the 13C NMR spectra, and correlated negatively with the organic free radical (OFR) signal associated with oxygen atoms (g = 2.0042). The hydrophobic aromatic structures correlate positively with the EPR OFR signal associated with carbon atoms (g = 2.0022). The data from the two spectroscopic magnetic techniques show that the used recuperation process is effective.

We discuss the applications of Nuclear Magnetic Resonance (NMR) to quantum information processing, focusing on the use of quadrupole nuclei for quantum computing. Various examples of experimental implementation of logic gates are given and compared to calculated NMR spectra and their respective density matrices. The technique of Quantum State Tomography for quadrupole nuclei is briefly described, and examples of measured density matrices in a two-qubit I = 3/2 spin system are shown. Experimental results of density matrices representing pseudo-Bell states are given, and an analysis of the entropy of theses states is made. Considering an NMR experiment as a depolarization quantum channel we calculate the entanglement fidelity and discuss the criteria for entanglement in liquid state NMR quantum information. A brief discussion on the perspectives for NMR quantum computing is presented at the end.