We present a method for producing accurate calculated T1 and spin density nuclear magnetic resonance images. A modified Carr-Purcell-Meiboom-Gill pulse sequence is used to obtain a series of images containing both T1 and T2 dependence. The image series is first analyzed to remove the T2 dependence. The resulting images are then analyzed, pixel by pixel, to generate an image containing T1 values and an image containing values proportional to spin density (SD). Tests performed on two phantoms containing solutions of various known T1's and H2O/D2O concentrations indicate that the T1 image values are accurate to better than 11% and the relative SD values agree to within one standard deviation.
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http://dx.doi.org/10.1118/1.595790 | DOI Listing |
Environ Res
January 2025
School of Environment and Energy Engineering, Anhui Jianzhu University, Hefei, 230601, China.
The efficient degradation of SAs is a significant challenge for the treatment of wastewater. To address this, the FeS@BC was prepared by calcining a mixture of pyrite and biomass, and used to activate peroxydisulfate (PDS) to degrade sulfadiazine (SDZ). The effect of carbon sources (wheat straw, rice husk, and corn cob) on catalytic activity of FeS@BC were investigated by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), total Fe dissolution and free radical quantification.
View Article and Find Full Text PDFMolecules
January 2025
Istituto di Biostrutture e Bioimmagini-CNR (IBB-CNR), Via De Amicis 95, I-80145 Napoli, Italy.
We perform DFT calculations with different hybrid (ωB97X-D and M05-2X) and double hybrid (B2PLYP-D3 and ωB2PLYP) functionals to characterize the lowest energy triplet excited states of naphthalene monomer and dimers in different stacking arrangements and to simulate their absorption spectra. We show that both excimer and localized triplet minima exist. In the former, the spin density is delocalized over the two monomers, adopting a face-to-face arrangement with a short inter-molecular distance.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
Laboratory for Heteroepitaxial Growth of Functional Materials & Devices, Department of Chemical & Biological Engineering, State University of New York (SUNY) at Buffalo, Buffalo, NY 14260, USA.
This study analyzes the calculation of the critical current density by means of Bean's critical state model, using the equation formulated by Gyorgy et al. and other similar equations derived from it reported in the literature. While estimations of using Bean's model are widely performed, improper use of different equations with different magnetic units and pre-factors leads to confusion and to significant errors in the reported values of .
View Article and Find Full Text PDFJ Magn Reson
January 2025
Center for Magnetic Resonance Research, University of Minnesota, 2021 6th Street SE, Minneapolis, MN 55455, USA. Electronic address:
In this work the effect of the geometric phase on time evolution of the density matrix was evaluated during nonadiabatic radiofrequency (RF) pulses with Sine amplitude modulation (AM) and Cosine frequency modulation (FM) functions of the RAFF (Relaxations Along a Fictitious Field) family, and the polarization between two energy level ½ spin system coupled by dipolar interaction was evaluated during the application of RF irradiation. The dependencies of the diagonal density matrix elements and the polarization on the rotational correlation times and the time during RF pulses were evaluated. The general treatment of the density matrix elements along with the polarization generated during RF pulses was unavailable thus far, and for the first time was here derived for the nonadiabatic case of the RAFF pulses.
View Article and Find Full Text PDFJ Comput Chem
January 2025
Department of Chemistry, Gottwald Center for the Sciences, University of Richmond, Richmond, Virginia, USA.
The energies and geometries of the lowest lying singlet and triplet states of the four diradicals formed by removing two H atoms from thiophene have been characterized. We utilized the highly correlated, multireference methods configuration interaction with single and double excitations with and without the Pople correction for size-extensivity (MR-CISD+Q and MR-CISD) and averaged quadratic coupled cluster theory (MR-AQCC). CAS (8,7) and CAS (10,8) active spaces involving σ, σ*, π, and π* orbitals were employed along with the cc-pVDZ and cc-pVTZ basis sets.
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