A mould for manufacturing a packing member from a liquid ceramic composition. The mould including a first part and a second part, in which the first and/or second mould parts are resiliently deformable and the first part and/or the second part include a plurality of open mould cavities. The first and second parts are operable to engage to form closed mould cavities, and the mould is operable to be moved from an open position in which the first and second parts are partially spaced by the deformation of a mould part and in which position mould cavities are open, to a partially closed position by reducing the deformation of the mould part and in which position some of the mould cavities are closed, and then to a closed position by further reducing the deformation of the mould part and in which position the first and second parts are engaged such that the mould cavities are closed.

A system for controlling hydrogen production from water-reactive aluminum includes a regulator. For example, the regulator may include a plurality of discrete objects and a retainer. Each one of the discrete objects includes aluminum in an activated form reactable with water to produce hydrogen. The retainer may encase the plurality of discrete objects collectively in an elongate shape having an axial dimension greater than a radial dimension. Within the elongate shape, the plurality of discrete objects may define voids therebetween. The retainer may be permeable across its thickness such that water may enter the retainer to react with the activated form of aluminum of the discrete objects in a local concentration that promotes heat generation for rapid reaction while water about the retainer may globally cool the material in the retainer, with the combination promoting rapid and efficient reaction of aluminum to produce hydrogen.

A spacer array including a plurality of spacers. Each spacer defines a longitudinal axis and includes a main body, a leading pin, and a trailing pin. The main body has a main body cross-sectional dimension. The leading pin extends from the main body and is upstream of the main body. The leading pin has a leading pin cross-sectional dimension. The trailing pin extends from the main body and is downstream of the main body. The trailing pin has a trailing pin cross-sectional dimension. The main body cross-sectional dimension is greater than the leading pin cross-sectional dimension and the trailing pin cross-sectional dimension.