Persistent current joints are crucial components of superconducting magnets—enabling the production of the high and ultra-stable magnetic fields required, for instance, for magnetic resonance measurements. At this critical juncture when persistent mode magnets containing commercial high temperature superconductors may soon become a reality, it is of value to take stock and evaluate current challenges faced in the field of jointing. This paper provides a review of progress made to date on the production and characterization of joints between the five major technological superconductors—NbTi, Nb3Sn, MgB2, BiSCCO and REBCO, including the materials that are used to make these joints.

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Recent researches have mainly displayed the significant role of stem cells in tissue renewal and homeostasis with their unique capacity to develop different cell types. These findings have clarified the importance of stem cells to improve the effectiveness of any cell therapy for regenerative medicine. Identification of purity and differentiation stages of stem cells are the greatest challenges of stem cell biology and regenerative medicine. The existing methods to carefully monitor and characterize the stem cells have some unwanted effects on the properties of stem cells, and these methods also do not provide real-time information about cellular conditions. These challenges enforce the usage of nondestructive, rapid, sensitive, high quality, label-free, cheep, and innovative chemical monitoring methods. In this context, vibrational spectroscopy provides promissing alternative to get new information into the field of stem cell biology for chemical analysis, quantification, and imaging of stem cells. Raman and infrared spectroscopy and imaging can be used as a new complimentary spectroscopic approaches to gain new insight into stem cell reseaches for future therapeutic and regenerative medicines. In this paper, recent developments in applications of vibrational spectroscopy techniques for stem cell characterization and identification are presented.

Superconducting thin films of Fe y Se 1−x Te x have been successfully grown on a variety of single-crystal substrate materials by radio frequency sputtering, and the effect of processing conditions on the microstructural development and superconducting properties has been investigated. The degree of unit cell anisotropy ( c a ratio), which is known to be linked to the superconducting transition temperature, is found to be sensitive to both Te and Fe content. However, the Te and Fe content cannot be varied independently, as the stable concentration of excess Fe is found to increase with Te content. Large scale compositional variations are found to exist in some samples, and it is believed that sub-micron scale chemical inhomogeneities are present in all samples. Post-deposition heat treatments carried out on the thin films indicate that the ternary Fe(Se, Te) phase is not very thermodynamically stable, partially transforming into Fe(Se, Te) 2 upon heating at modest temperatures for short times.