42 Design and development of shelter structures, modular structures, storage structures, and temporary housing and work structures for military, humanitarian, commerical, residential, industrial, and dining applications; design and development of shelter structures, modular structures, storage structures, temporary housing structures, and temporary work structures; design and development of shelter structures, modular structures, and temporary housing and work structures for use as housing units, medical units, school units, storage units, and operations and communication centers