The extreme complexity of petroleum products makes the detection and monitoring of their physicochemical properties a persistent challenge in petroleum refining. Low-field nuclear magnetic resonance (LF-NMR) technology, particularly time-domain nuclear magnetic resonance (TD-NMR), is a rapid and non-destructive technique for characterizing fluid states and properties and has become a valuable tool for detecting and monitoring state changes during petroleum refining processes. Because it is simple, cost-effective, and requires minimal sample preparation, LF-NMR is well suited to the determination of composition, content and other key physicochemical parameters when ultra-high resolution analysis is not required. This review summarizes the applications of LF-NMR in petroleum refining processes, including physical property determination, chemical composition analysis, mixture analysis and porous material characterization. Current methodological limitations are also discussed, and future directions are proposed to support safer and high-quality refinery operations.
The properties YGa3(BO3)4 and EuGa3(BO3)4 crystals doped with Mn2+ were investigated by electron paramagnetic resonance (EPR) and X‑ray diffraction methods in the temperature range 4–295 K. It was established that Mn2+ impurity ions substitute trivalent rare‑earth ions while preserving the symmetry of the substitution site. Heating of the crystals is accompanied by a smooth decrease in the splitting of the ground S state (spin S = 5/2) of the manganese ion.
The methods of application of a magnon Bose–Einstein condensate as a multiparticle spinor qubit are proposed. The basic principles of its operation are considered using the example of a Bose–Einstein condensate of magnons in superfluid ^3 He-B. Potential advantages of its application for quantum computing are demonstrated. In particular, a parallel method for reading the results of quantum computations on a multiparticle qubit is proposed. The feasibility of performing quantum computations on yttrium iron garnet films at room temperature is explored.
This review discusses the evolution of quantum optical magnetometers intended for biomagnetic measurements, with particular emphasis on magnetoencephalography. The development of modern optically pumped magnetometers has gradually shifted from the pursuit of ultimate magnetic sensitivity toward suitability for dense multichannel arrays. We describe the evolution of nonzero-field all-optical sensors, including single-beam design, operation in the ultra-low-field regime, vector measurements, and fiber-based optical power distribution. Taken together, these developments demonstrate that high-performance biomagnetic sensing can be achieved without RF excitation and with simplified optical layout, making all-optical nonzero-field Bell–Bloom magnetometers a promising platform for distributed neurodiagnostic systems.
