Abstract: Composite shafts and methods of making the same are described. The composite shafts include a plurality of composite elements arranged about an axis. The composite elements include first and second groups arranged at offset angles ±?. The groups of composite elements are configured to cooperate to allow the shaft to be flexible under bending and/or axial load and stiff under rotational load. The hollow shaft includes one or more axisymmetric radially-outward undulating portions and one or more axisymmetric narrow portions. The composite elements of groups are connected together in the radial direction along the narrow portions and the composite elements of the groups are not connected together in the radial direction along the undulating portions.

Abstract: A wet gypsum accelerator comprising ground product having a median particle size of from about 0.5 micron to about 2 microns and calcium sulfate dihydrate, water, and at least one additive selected from the group consisting of (i) an organic phosphonic compound, (ii) a phosphate-containing compound, or (iii) a mixture of (i) and (ii), is disclosed. Also disclosed are a method of preparing a wet gypsum accelerator, a method of hydrating calcined gypsum to form an interlocking matrix of set gypsum, a set gypsum-containing composition, and a set gypsum-containing product.