It has been suggested that edge-barrier pinning might cause the critical current density (Jc) in bridged superconducting films to increase. Subsequent work indicated that this edge-barrier effect does not impact bridges larger than 1 μm. However, we provide a theoretical assessment with supporting experimental data suggesting edge-barrier pinning can significantly enhance Jc for bridges of a few microns or even tens of microns thus skewing any comparisons among institutions. As such, when reporting flux pinning and superconductor processing improvements for Jc comparisons, the width of the sample has to be taken into consideration as is currently done with film thickness.

We present the results of numerical analysis of normal zone propagation in a stack of Y Ba2Cu3O7−x coated conductors which imitates a pancake coil. Our main purpose is to determine whether the quench protection quality of such coils can be substantially improved by increased contact resistance between the superconducting film and the stabilizer. We show that with increased contact resistance the speed of normal zone propagation increases, the detection of a normal zone inside the coil becomes possible earlier, when the peak temperature inside the normal zone is lower, and stability margins shrink. Thus, increasing contact resistance may become a viable option for improving the prospects of coated conductors for high Tc magnets applications.

The paper presents results from an experimental investigation on the freezing and thawing behavior of internally cured concrete. Air-entrained internally cured concrete was tested in a series of mixtures. The internally cured concrete was designed where a portion of the normal-weight fine aggregate was replaced with an equivalent volume of pre-wetted lightweight fine aggregate. The internally cured concrete was then exposed to cyclic freezing and thawing following the ASTM C666A procedure. This work was performed to determine whether properly designed, internally cured, air-entrained concrete may have an increased susceptibility to freeze–thaw damage. It is shown that when concrete is designed with a low water/cement ratio (w/c) (approximately 0.42 or lower) and a volume of internal curing water is added to match the chemical shrinkage volume, the internally cured concrete mixtures showed a very low potential for freeze–thaw damage (comparable to that of conventional concrete). The work did show that when water remains in the lightweight aggregates (because of a higher w/c that may not draw the water from the aggregate or when substantially more internal curing water is used than necessary), freeze–thaw damage may occur.

The use of superabsorbent polymers (SAPs) to produce internally cured concrete has been shown to be effective in reducing the potential for restrained shrinkage cracking of high performance concrete mixtures. However, not much is known regarding the freeze-thaw durability of concrete mixtures that incorporate SAPs for internal curing (IC). When SAP particles desorb (or partially desorb) the "water" (pore fluid) they contain for the purposes of IC, some believe that the void space created by these particles can provide enough empty voids to accommodate the additional volume caused by water expansion upon freezing. This paper investigates the freeze-thaw durability of internally cured concrete by the use of SAPs. It has been shown that internally cured concretes made using SAP demonstrate good freeze-thaw performance when the concrete is air entrained. When the SAP was used in concrete without air entrainment it did not provide sufficient freeze-thaw durability.