Transport critical current of Solenoidal MgB2/Cu Coils Fabricated Using a Wind-Reaction In-situ Technique

In this letter, we report the results of transport Jc of solenoid coils upto 100 turns fabricated with Cu-sheathed MgB2 wires using a wind-reaction in-situ technique. Despite the low density of single core and some reaction between Mg and Cu-sheath, our results demonstrate the decrease in transport Jc with increasing length of MgB2 wires is insignificant. Solenoid coils with diameter as small as 10 mm can be readily fabricated using a wind-reaction in-situ technique. The Jc of coils is essentially the same as in the form of straight wires. A Jc of 133,000 A/cm2 and 125,000 A/cm2 at 4 K and self field has been achieved for a small coil wound using Cu-sheathed tape and Cu-sheathed wire respectively. These results indicate that the MgB2 wires have a great potential for lage scale applicationsComment: 6 pages, 4 figures, 1 tabl

"Medicine is still against Black people": Mapping and visualising intersections of social inequalities, community mistrust, and vaccine hesitancy in online and physical spaces in the UK and US

Funded by the British Academy, this report is part of a research project entitled “Mapping and visualising intersections of social inequalities, community mistrust, and vaccine hesitancy in online and physical spaces in the UK and US”. The report investigates social, cultural, and political factors underlying vaccine hesitant beliefs and ideas among minoritised communities in the United Kingdom (UK) and the United States of America (US). The data is collected through interviews and focus groups with vaccine-hesitant individuals within various religiously, ethnically, and racially minoritised communities, interviews with medical practitioners, and through thematic analysis of vaccine communication in Twitter and Telegram during the COVID-19 pandemic

The double Ringel-Hall algebra on a hereditary abelian finitary length category

In this paper, we study the category $\mathscr{H}^{(\rho)}$ of semi-stable coherent sheaves of a fixed slope $\rho$ over a weighted projective curve. This category has nice properties: it is a hereditary abelian finitary length category. We will define the Ringel-Hall algebra of $\mathscr{H}^{(\rho)}$ and relate it to generalized Kac-Moody Lie algebras. Finally we obtain the Kac type theorem to describe the indecomposable objects in this category, i.e. the indecomposable semi-stable sheaves.Comment: 29 page

Graphene micro-substrate induced high electron-phonon coupling in MgB2

Electron-phonon coupling strength was studied in graphene-MgB2 composites to explore the possibilities for a higher superconducting transition temperature (Tc). For the first time in the experimental work on MgB2, the Raman active E2g mode was split into two parts: a softened mode corresponding to tensile strain and a hardened mode attributed to the carbon substitution effect. The tensile strain effect is suggested to improve Tc of graphene-MgB2 composites because it increases the electron-phonon coupling strength of MgB2

Enhancement of Critical Current Density in low level Al-doped MgB2

Two sets of MgB2 samples doped with up to 5 at. % of Al were prepared in different laboratories using different procedures. Decreases in the a and c lattice parameters were observed with Al doping confirming Al substitution onto the Mg site. The critical temperature (Tc) remained largely unchanged with Al doping. For 1 - 2.5 at.% doping, at 20K the in-field critical current densities (Jc's) were enhanced, particularly at lower fields. At 5K, in-field Jc was markedly improved, e.g. at 5T Jc was enhanced by a factor of 20 for a doping level of 1 at.% Al. The improved Jcs correlate with increased sample resistivity indicative of an increase in the upper critical field, Hc2, through alloying.Comment: 17 pages, 4 figures, to be published in Superconductor Science and Technolog

State of the art in tundish with induction heating (IH) for clean steel casting

The electrical magnetic field plays an essential role in controlling the molten steel flow, heat transfer and migration of inclusions. Electromagnetic induction heating technology utilizes the force or heat effect of the electromagnetic field or simultaneously uses force and heat effect to control molten metal flow, heat transfer and the movement of non-metallic inclusion in the metallurgical process, to optimize the metallurgical process, improve production efficiency, quality, and performance. In this work, the development of IH in continuous casting tundish was outlined. The current theoretical and experimental research on electromagnetic induction heating for molten steel flow and heat transfer were introduced. Meanwhile, the electromagnetic purification mechanism and research progress of non-metallic inclusions in molten steel were analyzed. Finally, the prospects for the application of electromagnetic IH are proposed