## Geometry of the toroidal N-helix: optimal-packing and zero-twist

Publication: Research - peer-review › Journal article – Annual report year: 2012

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**Geometry of the toroidal N-helix: optimal-packing and zero-twist.** / Olsen, Kasper; Bohr, Jakob.

Publication: Research - peer-review › Journal article – Annual report year: 2012

### Harvard

*New Journal of Physics*, vol 14. DOI: 10.1088/1367-2630/14/2/023063

### APA

*New Journal of Physics*,

*14*. DOI: 10.1088/1367-2630/14/2/023063

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### MLA

*New Journal of Physics*. 2012. 14. Available: 10.1088/1367-2630/14/2/023063

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### Bibtex

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### RIS

TY - JOUR

T1 - Geometry of the toroidal N-helix: optimal-packing and zero-twist

AU - Olsen,Kasper

AU - Bohr,Jakob

PY - 2012

Y1 - 2012

N2 - Two important geometrical properties of N-helix structures are influenced by bending. One is maximizing the volume fraction, which is called optimal-packing, and the other is having a vanishing strain-twist coupling, which is called zero-twist. Zero-twist helices rotate neither in one nor in the other direction under pull. The packing problem for tubular N-helices is extended to bent helices where the strands are coiled on toruses. We analyze the geometry of open circular helices and develop criteria for the strands to be in contact. The analysis is applied to a single, a double and a triple helix. General N-helices are discussed, as well as zero-twist helices for N > 1. The derived geometrical restrictions are gradually modified by changing the aspect ratio of the torus.

AB - Two important geometrical properties of N-helix structures are influenced by bending. One is maximizing the volume fraction, which is called optimal-packing, and the other is having a vanishing strain-twist coupling, which is called zero-twist. Zero-twist helices rotate neither in one nor in the other direction under pull. The packing problem for tubular N-helices is extended to bent helices where the strands are coiled on toruses. We analyze the geometry of open circular helices and develop criteria for the strands to be in contact. The analysis is applied to a single, a double and a triple helix. General N-helices are discussed, as well as zero-twist helices for N > 1. The derived geometrical restrictions are gradually modified by changing the aspect ratio of the torus.

KW - Physics

KW - Coiled Carbon Nanotubes

KW - Self-Contact

KW - Dna Configurations

KW - Elastic Stability

KW - End Conditions

KW - Mechanics

KW - Plasmids

KW - Ideal

KW - Transitions

KW - Shapes

U2 - 10.1088/1367-2630/14/2/023063

DO - 10.1088/1367-2630/14/2/023063

M3 - Journal article

VL - 14

JO - New Journal of Physics

T2 - New Journal of Physics

JF - New Journal of Physics

SN - 1367-2630

ER -