Pure-in-phase correlation spectroscopy

The two-dimensional PICSY experiment (pure-in-phase correlation spectroscopy Vincent et al., 1992, 1993) can also be regarded as a highly selective E.TACSY experiment. In these experiments, coherence transfer is accomplished by doubly selective rf irradiation with relatively low rf amplitudes, which are on the order of 50 Hz for each sideband. Hence, the polarization state of a passive spin remains essentially undisturbed if mir where is the smallest frequency difference between... 

Broadband Hartmann-Hahn transfer can also be of assistance in alternative approaches to determine coupling constants that do not rely on E.COSY-type multiplets that are separated by large one-bond couplings. The homonuclear two-dimensional PICSY (pure in-phase correlation spectroscopy) experiment (Vincent et al., 1992, 1993), which is based on selective Hartmann-Hahn transfer using doubly selective irradiation, can... 

Mismatch-optimized IS transfer Nuclear Overhauser enhancement Nuclear Overhauser effect spectroscopy Numerically optimized isotropic-mbdng sequence Preservation of equivalent pathways Pure in-phase correlation spectroscopy Planar doubly selective homonuclear TACSY Relayed correlation spectroscopy Radiofrequency... 

Observations were made of lipid-protein phases in which the structure is determined mainly by the protein. Raman spectroscopy is a useful method for structure analysis of such phases. The structures described above were analyzed successfully by an x-ray diffraction technique. Lipid-protein complexes, however, are often amorphous, and alternative methods to study their structures are therefore needed. It was demonstrated that Raman spectroscopy can be used to obtain structural information about lipid-protein interaction (16, 17). It is thus possible to determine the conformation as well as the type of environment of the lipid molecules. With the protein, interpretation is more complicated. It is usually possible to determine whether the complex has the same protein conformation as the component used in the preparation, or, if a change occurs, it may be possible to correlate it with denaturation of the pure protein. For complexes formed by long-chain alkyl phosphates and insu-... 

Attempts to correlate the catalytic activity of unpromoted and potassium-promoted iron Fischer-Tropsch catalysts to their bulk phase compositions as determined using Mossbauer spectroscopy are reported. The CO-conversion of both catalysts declined with time-on-stream. Samples of the umnpromoted catalyst were primarily Fe C and this phase gradually decreased to become essentially pure Fe O after 450 hours time-on-stream. In contrast, the potassium-promoted catalyst was primarily Fe C after pretreatment and remained this phase during 400 hours of synthesis. Thus, both Fe C and Fe C phases are about equally active for Fischer-Tropsch synthesis but exhibit much different stability during the course of the synthesis reaction. 

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