Hybrid modelling methodology for system design

In the face of rapid development in information technology coupled with a growing dynamism in global markets, manufacturing systems have to be re-constructed for short term or long term goal. Such innovations promise to lead to a new competitive stage, which typically involve design of function, information and behaviour of systems. In order to design the system, simulation has often been chosen. However, simulation has proved limited and fails to aid design of such a complex systems because of consuming much computing time and cost, especially when modelling larger systems. Thus, there is a need to seek a new approach, in a way that results in simulating such a large manufacturing system with less demand on computing time and cost. This study researches into a hybrid modelling approach to minimise these limitations. It includes proposing a hybrid modelling methodology and developing a hybrid modelling tool. The methodology integrates simulation and metamodelling techniques. The metamodel employed in the study possesses, not only characteristics of conventional metamodels in terms of representing relationships in quantity, but also in time lapse. This is the originality of the study and the significant distinction between this research and application of metamodelling in conventional ways. The hybrid modelling tool is developed to support and demonstrate the identified hybrid methodology. LISP has been used as the software language for the hybrid modelling tool. The result of this work concludes that the hybrid modelling approach is capable of simulating a complex manufacturing system with less demands on the computer. The work reported in this thesis has been carried out in conjunction with the EPSRC research project, Hierarchical Manufacturing System Modelling (HMSM) (GR/F96549), to produce an Integrated Design and Modelling Methodology (IDEM). The project was initially a collaborative research program including Loughborough University of Technology (LUT), Morris Crane Ltd., of Loughborough and GEC Large Machine, of Rugby. The experience of these collaborators has proved most valuable in supporting the research, and have provided a cross section of views and comments. The research reported in this thesis is set in the context of the HMSM Research group at Loughborough

Multiresponsive Square Hybrid Nanosheets of POSS-Ended Hyperbranched Poly(ether amine) (hPEA)

We demonstrated a novel square hybrid nanosheet with a ultrathin thickness for the first time, which was fabricated by self-assembly of hyperbranched poly­(ether amine) (hPEA526) containing anthracene (AN) moieties and heptaisobutyl polyhedral oligomeric silsesquioxane (POSS). TEM and AFM images reveal that the average edge length and thickness of the hybrid nanosheets formed by <b>HP1</b> is 1.2 ± 0.2 μm and 4.5 ± 0.5 nm, respectively. POSS prefers the ordered crystallized aggregation in the formation of the regular square nanosheets, which is confirmed by WAXD and DSC studies. Moreover, these nanosheets are cross-linked through dimerization of anthracene moieties which makes the nanosheets more stable. The other functional moieties such as naphthalene, pyrene, and dodecane can also be easily introduced into the hybrid nanosheets through the same way. The obtained hybrid nanosheets exhibit the multiresponses to temperature and pH, and their dispersion in water can be controlled by temperature. The fluorescence of the hybrid nanosheets decreases with the increasing temperature and pH. The discovery of the hybrid nanosheets is believed to provide a potential guiding significance on the preparation of the functional nanosheets by self-assembly of polymers

Size-Tunable Nanosheets by the Crystallization-Driven 2D Self-Assembly of Hyperbranched Poly(ether amine) (hPEA)

We reported the preparation of uniform square nanosheets with tunable size by the living crystallization-driven 2D self-assembly of hyperbranched poly­(ether amine) capped with heptaisobutyl polyhedral oligomeric silsesquioxane (POSS). The nanosheets of <b>HP1</b> containing both anthracene (AN) and POSS moieties in a solution of 1,4-dioxane and water can be fragmented after the melting of the POSS moieties upon heating and can be regenerated after the recrystallization of POSS moieties, which was confirmed by microdifferential scanning calorimetry (μDSC) and dynamic light scattering (DLS) studies and transmission electron microscopy (TEM) images. The obtained fragmented nanosheets (<b>HP1-NSs</b>) with a relatively small size were used as seeds for the 2D epitaxial living growth of <b>HP1</b> unimers to fabricate uniform square nanosheets with tunable edge lengths from ∼0.5 to ∼4.5 μm, which is dependent on the unimer-to-seed ratio. Furthermore, dual-component nanosheets can also be obtained by random cocrystallization of <b>HP1</b> with another type of hPEA capped with POSS and ferrocene (<b>HP2</b>). This crystallization-driven 2D self-assembly behavior of POSS-capped hPEA might provide potential significance in the preparation of functional nanosheets with different sizes and components, which could be further used as templates for inorganic nanosheets and 2D-platforms for metal nanoparticles

Hybrid Core–Shell Microspheres from Coassembly of Anthracene-Containing POSS (POSS-AN) and Anthracene-Ended Hyperbranched Poly(ether amine) (hPEA-AN) and Their Responsive Polymeric Hollow Microspheres

We demonstrated a novel core–shell microsphere (CSM) fabricated from coassembly of anthracene-ended hyperbranched poly­(ether amine) (hPEA-AN) and anthracene containing polyhedral oligomer silsesquioxane (POSS-AN). The obtained CSMs are cross-linked through photodimerization of anthracene and possess the well-defined core–shell structure according to the images of SEM, TEM, and AFM. The shell of the obtained CSM is comprised of hPEA-AN, while POSS-AN prefers the ordered crystallized aggregation in the core. The size of the obtained CSMs is uniform and tunable. With the increasing content of hPEA-AN in the coassembly, the diameter of CSMs decreased from 930 to 616 nm, while the thickness of shell increased from 95 to 170 nm. Moreover, polymeric hollow microsphere (PHM) was prepared by removing the POSS-AN core of CSM in hydrofluoric acid (HF). The obtained PHM is amphiphilic and fluorescent, and its size is responsive to environmental stimulus such as temperature and pH. PHM can be used in the encapsulation and controlled release of guest molecules. Moreover, the controlled release of guest molecules from PHM can be monitored by itself fluorescence change

Responsive Fluorescent Nanorods from Coassembly of Fullerene (C₆₀) and Anthracene-Ended Hyperbranched Poly(ether amine) (AN-hPEA)

We herein demonstrated a novel multiresponsive fluorescent nanorod based on C₆₀, which is fabricated through the versatile coassembly of fullerene C₆₀ and anthracene-ended hyperbranched poly­(ether amine) (AN-hPEA). The supramolecular nanorods (C₆₀@AN-hPEA) can be further cross-linked through photodimerization of anthracene, and the size of the obtained nanorods is 2–12 μm in length and 50–90 nm in diameter. C₆₀@AN-hPEA nanorods are amphiphilic, responsive, and fluorescent. The fluorescence of C₆₀@AN-hPEA nanorods in aqueous solution is responsive to temperature and pH. The C₆₀@AN-hPEA-1/4 nanorods exhibit the interesting temperature-enhanced fluorescence, while the fluorescence intensity of AN-hPEA without C₆₀ decreases with the increasing temperature. Detailed fluorescence study revealed that the temperature-enhanced fluorescence behavior of C₆₀@AN-hPEA-1/4 nanorods might be ascribed to the static quenching of the excited anthracene by C₆₀

CO₂‑Responsive Polymer Single-Chain Nanoparticles and Self-Assembly for Gas-Tunable Nanoreactors

CO₂-responsive polymer single-chain nanoparticles (SCNPs) and self-assembled micellar aggregates are investigated as gas-controlled, rate- and size-tunable nanoreactors of gold nanoparticles (AuNPs). On one hand, SCNPs are prepared from a random copolymer of poly­{(<i>N</i>,<i>N</i>-dimethylaminoethyl methacrylate)-<i>co</i>-4-methyl-[7-(methacryloyl)­oxy-ethyl-oxy]­coumarin} (P­(DMAEMA-<i>co</i>-CMA)). When dispersed in aqueous solution, individual nanoparticles can undergo reversible swelling/shrinking under alternating CO₂/N₂ stimulation as a result of the reversible protonation/deprotonation of tertiary amine groups. On the other hand, tadpole-like single-chain “Janus” nanoparticles (SCJNPs) are prepared using an amphiphilic diblock copolymer of PS-<i>b</i>-P­(DMAEMA-<i>co</i>-CMA) (PS is hydrophobic polystyrene). This type of SCJNPs can self-assemble into core–shell micellar aggregates in aqueous solution. Under CO₂/N₂ stimulation, the collective swelling/shrinking of SCJNPs within the micelle results in large, reversible volume change. Both P­(DMAEMA-<i>co</i>-CMA) SCNPs and PS-<i>b</i>-P­(DMAEMA-<i>co</i>-CMA) SCJNP micelles are explored as gas-tunable nanoreactors for AuNPs. The rate of AuNP formation increases under CO₂ stimulation and decreases upon N₂ bubbling, which makes it possible to tune the reaction rate up and down (on/off switching) by using the two gases. Moreover, using the micelles of SCJNPs, whose volume can be controlled over a wide range by adjusting the CO₂ stimulation strength, variable-size AuNPs and their aggregates are obtained with continuous redshift of the surface plasmon resonance (SPR) into the long-wavelength visible light region

Numbers of <i>C9orf72</i> repeats in white blood cell DNA of monozygous twins.

<p>T: twin pair, M: member,</p>¶<p>and §: CNS donors as well (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070007#pone-0070007-t001" target="_blank">Table 1</a>), NA: not applicable,</p>†<p>: cause and age of death,</p><p>♦: triplet, MZ: monozygous, DZ: dizygous, PMA: progressive muscular atrophy.</p

Early and late onset somatic mutations.

<p>In the human cell lineage, germline progenitor cells that produce the gametes (at the horizontal dashed line) are formed before the somatic cell lineages start dividing. The progenitor cells and their daughter cells for 4 somatic cell lines are shown. (A) Here a somatic mutation has occurred in a CNS progenitor cell, which is passed on to its daughter cells (red-filled circles) but which leaves the other cell lines intact. Comparing DNA from both the CNS and from white blood cells will reveal this somatic mutation. (B) The somatic mutation here has affected an early stem cell, so most or all of the somatic cell lines will contain the mutation. This mutation can be detected if one monozygous twin has a white blood cell mutation and the other does not.</p

Size of <i>C9orf72</i> hexanucleotide repeats in CNS and WBC paired samples.

<p>WBC repeats were not tested when CNS repeats were less than 8 in number (except for 3 samples).</p>¶<p>and §: twins as well as CNS donor (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070007#pone-0070007-t002" target="_blank">Table 2</a>), NT: not tested.</p

Highly Efficient SO₂ Absorption and Its Subsequent Utilization by Weak Base/Polyethylene Glycol Binary System

A binary system consisting of polyethylene glycol (PEG, proton donor)/PEG-functionalized base with suitable basicity was developed for efficient gas desulfurization (GDS) and can be regarded as an alternative approach to circumvent the energy penalty problem in the GDS process. High capacity for SO₂ capture up to 4.88 mol of SO₂/mol of base was achieved even under low partial pressure of SO₂. Furthermore, SO₂ desorption runs smoothly under mild conditions (N₂, 25 °C) and no significant drop in SO₂ absorption was observed after five-successive absorption–desorption cycles. On the other hand, the absorbed SO₂ by PEG₁₅₀MeIm/PEG₁₅₀, being considered as the activated form of SO₂, can be directly transformed into value-added chemicals under mild conditions, thus eliminating the energy penalty for SO₂ desorption and simultaneously realizing recycle of the absorbents. Thus, this SO₂ capture and utilization (SCU) process offers an alternative way for GDS and potentially enables the SO₂ conversion from flue gas to useful chemicals as a value-added process