Geometry and topology of microscopic ribbons

With a focus on the organic molecule that every living organism contains, this report strives to characterise the mechanical properties of DNA. For a contour length that far exceeds the thickness or diameter of a chain, the geometrical and topological configurations can be described by simplified mo...

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Main Author: Cheong, Kyra Kay Yen
Other Authors: Yong Ee Hou
Format: Final Year Project (FYP)
Language:English
Published: Nanyang Technological University 2022
Subjects:
Online Access:https://hdl.handle.net/10356/156991
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author Cheong, Kyra Kay Yen
author2 Yong Ee Hou
author_facet Yong Ee Hou
Cheong, Kyra Kay Yen
author_sort Cheong, Kyra Kay Yen
collection NTU
description With a focus on the organic molecule that every living organism contains, this report strives to characterise the mechanical properties of DNA. For a contour length that far exceeds the thickness or diameter of a chain, the geometrical and topological configurations can be described by simplified models. Starting with the discrete freely jointed chain (FJC) model, the qualitative explanation provided a stepping stone for the development into the continuous limit of the worm-like chain (WLC). The applicability of these models, especially the latter, has demonstrated the ability to accurately predict the behaviour of organic polymers in stretching and twisting experiments conducted by researchers since the 70s. In this report, the computing capacity of a simulation that employs the Monte Carlo method has provided a reliable means of obtaining the geometrical and topological values resulting from the WLC model within certain force regimes. The effect of a combination of external force and torque applied to the model reveals the relationship between the geometrical and topological conformations of the chain. With increasing external force, the extension of the chain rises rapidly, but as full extension is approached, the relative extension becomes smaller as the entropic spring behaviour diminishes. Additionally, applying an external torque to the chain delineates the inability to affect the topological parameter denoted by the linking number. The results of these simulations were compared to past experiments and have shown to be a reliable means of accurately calculating the ensemble averages of measurable properties exhibited by organic polymers, particularly DNA.
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spelling ntu-10356/1569912023-02-28T23:12:08Z Geometry and topology of microscopic ribbons Cheong, Kyra Kay Yen Yong Ee Hou School of Physical and Mathematical Sciences EeHou@ntu.edu.sg Science::Physics With a focus on the organic molecule that every living organism contains, this report strives to characterise the mechanical properties of DNA. For a contour length that far exceeds the thickness or diameter of a chain, the geometrical and topological configurations can be described by simplified models. Starting with the discrete freely jointed chain (FJC) model, the qualitative explanation provided a stepping stone for the development into the continuous limit of the worm-like chain (WLC). The applicability of these models, especially the latter, has demonstrated the ability to accurately predict the behaviour of organic polymers in stretching and twisting experiments conducted by researchers since the 70s. In this report, the computing capacity of a simulation that employs the Monte Carlo method has provided a reliable means of obtaining the geometrical and topological values resulting from the WLC model within certain force regimes. The effect of a combination of external force and torque applied to the model reveals the relationship between the geometrical and topological conformations of the chain. With increasing external force, the extension of the chain rises rapidly, but as full extension is approached, the relative extension becomes smaller as the entropic spring behaviour diminishes. Additionally, applying an external torque to the chain delineates the inability to affect the topological parameter denoted by the linking number. The results of these simulations were compared to past experiments and have shown to be a reliable means of accurately calculating the ensemble averages of measurable properties exhibited by organic polymers, particularly DNA. Bachelor of Science in Applied Physics 2022-05-06T02:57:39Z 2022-05-06T02:57:39Z 2022 Final Year Project (FYP) Cheong, K. K. Y. (2022). Geometry and topology of microscopic ribbons. Final Year Project (FYP), Nanyang Technological University, Singapore. https://hdl.handle.net/10356/156991 https://hdl.handle.net/10356/156991 en application/pdf Nanyang Technological University
spellingShingle Science::Physics
Cheong, Kyra Kay Yen
Geometry and topology of microscopic ribbons
title Geometry and topology of microscopic ribbons
title_full Geometry and topology of microscopic ribbons
title_fullStr Geometry and topology of microscopic ribbons
title_full_unstemmed Geometry and topology of microscopic ribbons
title_short Geometry and topology of microscopic ribbons
title_sort geometry and topology of microscopic ribbons
topic Science::Physics
url https://hdl.handle.net/10356/156991
work_keys_str_mv AT cheongkyrakayyen geometryandtopologyofmicroscopicribbons