Recent Work on the Design and Construction of Air Inflated Structures

AbstractOver the last few years our practice has been responsible for the structural design of a number of lightweight structures that achieve their structural stability by inflating elements of fabric structure. The paper will explain the design rationale of key examples; describing the structural forms, methods of analysis and design, and the detailing, materials, and methods of fabrication. The largest and most complex of these structures to date is a demountable stage set structure for the Cirque du Soleil “Toruk: First Flight” show, comprising two 15 metre high and 20 metre wide structures. The stage set structures form ‘trees’ on which acrobats climb and perform. Each structure incorporates a high level access gantry with acrobat suspension and counterweight systems, as well as a secondary inflatable skin cladding. The entire primary structure and cladding system is constructed from inflated fabric elements using internal pressures ranging from 0.5 KN/m2 up to 90 KN/m2, and are deflated down to less than 5% of their erected volume for transport between venues. Other examples of our work described will include temporary pavilions with clear spans of up to 25 metres, using a combination of air tight and air permeable elements. Also a range of wide span structures that we describe as “semi-permanent” that are capable of resisting full environmental wind and snow loading, and that are fully demountable but that can also be erected for extended periods of time in a single location

Predicted transmembrane topologies of OR1 (A), OR2 (B) and OR3 (C), with variable sites highlighted in red.

<p>The double line indicates the membrane region, with extracellular and cytoplasmic sides labelled.</p

Likelihood ratio tests between concatenated sequences.

<p>model A assumes complete homogeneity among genes, while model B assumes different substitution rates but the same pattern of nucleotide substitution for each gene.</p

Summary statistics for odorant receptors OR1, OR2 and OR3 from <i>Ctenopseustis</i> and <i>Planotortrix</i> species.

a<p>number of sequences.</p>b<p>number of codons.</p>c<p>tree length.</p>d<p>transition/transversion ratio.</p>e<p>dN/dS under M0.</p>f<p>dN/dS under M3.</p

Unrooted phylogenetic tree of all lepidopteran odorant receptors within Genbank as of 8 November, 2010.

<p>The neighbour joining tree was constructed from dayhoff amino acid distances. The positions of OR1, OR2 (Orco), and OR3 from <i>Epiphyas postvittana</i> are indicated with arrows (EpOR1, EpOR2, and EpOR3), while the Orco and sex pheromone receptor clades are highlighted by semicircles.</p

Predicted transmembrane topology of OR30 from <i>P</i>. <i>excessana</i> and <i>P</i>. <i>octo</i>.

<p>Variable sites highlighted in red indicating amino acid substitutions in <i>P</i>. <i>octo</i>, black indicating substitutions in <i>P</i>. <i>excessana</i>, red-black indicating independent substitutions in <i>P</i>. <i>octo</i> and <i>P</i>. <i>excessana</i> compared to a predicted common ancestor. The double line indicates the transmembrane region, with extracellular and cytoplasmic sides labelled.</p

PAML analysis of OR30 across endemic New Zealand leafroller moths.

<p>Maximum likelihood tree of OR30 othologues from <i>Ctenopseustis obliquana</i> (CoblOR30), <i>C</i>. <i>herana</i> (CherOR30), <i>Planotortrix octo</i> (PoctOR30) and <i>P</i>. <i>excessana</i> (PexcOR30). dN, dS and dN/dS values were generated using the M3 model.</p

Predicted transmembrane topology of OR7.

<p>Variable sites between <i>P</i>. <i>octo</i> and <i>P</i>. <i>excessana</i> are highlighted. Red dots indicate the position of amino acid substitutions in <i>P</i>. <i>octo</i>, and black dots amino acid substitutions in <i>P</i>. <i>excessana</i> compared to a predicted common ancestor. The double line indicates the transmembrane region, with extracellular and cytoplasmic sides labelled.</p

Amino acid identity matrix for <i>Ctenopseustis</i> and <i>Planotortrix</i> orthologues of OR1, OR2 and OR2.

a<p>Ctenopseustis obliquana.</p>b<p>C. herana.</p>c<p>Planotortrix excessana.</p>d<p>P. octo.</p>e<p>P. notophaea.</p>f<p>Epiphyas postvittana.</p>g<p>BmOR1.</p>h<p>BmOR2.</p>i<p>BmOR49.</p

Ratio of the relative amino acid differences per domain averaged for OR1, OR2 (Orco) and OR3 across <i>Ctenopseustis obliquana</i>, <i>C. herana</i>, <i>Planotortrix octo</i>, <i>P. excessana</i> and <i>P. notophaea</i>.

<p>The ratio for each domain is the average of the number of amino acid differences divided by the number of expected differences. Expected differences were calculated by multiplying the length of the domain by the total number of differences per protein then dividing by the length of the protein. The ratio would be 1 if the amino acid changes occurred at the same rate across the entire protein. N-ter = N terminus; TM1-TM7 = transmembrane domains 1–7; IL1-3 = internal loops 1–3; EL1-3 = external loops 1–3; C-ter = C terminus. ND = not determined.</p