1,868 research outputs found
Molecular simulations of self-assembly and adsorption in non-aqueous media
No full textMolecular simulations are used to investigate key structural and thermodynamic
properties of molecules relevant to non-aqueous chemical formulations. Block and
gradient copolymers are simulated using both coarse-grained and atomistic models
for use as viscosity modifiers and dispersants in lubricants. The second section covers
simulations of asphaltenes, which are a problematic oil contaminant in the shipping
industry. Throughout, simulations are compared to experiments in collaboration
with industry partners Infineum UK, academic groups, and central experimental
facilities.
The first part of the thesis concerns amphiphilic block and gradient copolymers.
Their structures in solution and adsorbed onto surfaces are surveyed using a simple
bead-spring model. Gradient copolymers are found to be more sensitive to temperature,
both in the case of an isolated polymer and when self-assembled into
micelles. The micelles are characterised using simulated scattering profiles, which
compare favourably to existing experimental data. The adsorption of copolymers
onto solid surfaces is modelled with an attractive potential that is selective for the
solvophobic beads. Both types of copolymer form adsorbed films with persistent
micelle-like structures, but the gradient copolymers show a stronger dependence on
the strength of the surface interactions and the temperature. Some comparisions
are made to atomistic simulations of a butyl prop-2-enoate/prop-2-enoic acid (butyl
acrylate/acrylic acid) copolymer in n-dodecane at room temperature.
Amphiphilic copolymers also show surfactant behaviour at liquid-liquid interfaces.
The effects of polymer architecture on the structural and thermodynamic properties
of the liquid-liquid interface are studied using molecular simulations. Block and gradient
copolymer surfactants are represented with coarse-grained, bead-spring models,
where each component of the polymer favours one or the other liquid. Gradient
copolymers have a greater concentration at the interface than do block copolymers,
because the gradient copolymers adopt conformations partially aligned with the interface.
Gradient copolymers are found to be more potent surfactants, reducing
the interfacial tension more than block copolymers at a given surface excess. The
coarse-grained simulations are complemented by atomistic simulations of acrylici
acid/styrene copolymers at the chloroform-water interface, which have been studied
in experiments. The agreement between the simulations (both coarse-grained and
atomistic) and experiments is shown to be excellent.
The second part of the project is focused on asphaltenes, which are aromatic molecules
found in high-molecular-weight fractions of crude oil. They dissolve in aromatic solvents
like toluene, but not in aliphatic solvents like heptane. Low solubility leads to
aggregate formation, and many problems in transport applications. Natural asphaltene
fractions contain complex mixtures of molecules which vary widely between
sources of crude oil, and so the chemical and structural properties are difficult to
characterise. To make a study tractable, three synthetic asphaltenes containing
different oxidation states of sulfur in binary mixtures of toluene and heptane are
studied. Aggregate formation is investigated using a combination of small-angle
neutron scattering (SANS), as part of a collaboration with the University of Leeds,
and molecular-dynamics (MD) simulations. The extent of aggregation is found to
depend strongly on both the composition of the solvent and the functionality of
the sulfur atom. The microscopic structures of the nanoaggregates are detailed using
simulation visualisations, and radial distribution functions involving sulfur and
oxygen atoms. The variations in clustering behaviour between functional groups
and solvents is attributed mainly to the electrostatic interactions between the polar
sulfur-containing functional groups, which stabilise ‘head-to-tail’ configurations
in the sulfoxide aggregates, and more complex branched structures in the sulfone
aggregates.
The work documented in this thesis has had impact beyond just academic interest.
As a result of the simulations, industry partners Infineum have set up a synthetic
program to make gradient copolymers, with the coarse-grained simulations
providing general design rules to inform the molecular structure. The simulations
of asphaltenes, and the collaboration with the University of Leeds, were directly
responsible for the SANS experiments performed. The overarching theme of the
thesis is the use of molecular simulations to guide industry projects and inform
experiments, and the work presented has set a strong foundation for continuing
collaboration with industry, central facilities, and experimental groups
R v G and R [2003] UKHL 50, House of Lords
No full textEssential Cases: Criminal Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in R v G and R [2003] UKHL 50, House of Lords. The document also included supporting commentary from author Jonathan Herring.</p
Stonewall Jackson : gudabenådad general
No full textDiscussion of Swedish author Frans G. Bengtsson's classic 1920s essay on Confederate general Thomas Jonathan Jackson
Stonewall Jackson : gudabenådad general
No full textDiscussion of Swedish author Frans G. Bengtsson's classic 1920s essay on Confederate general Thomas Jonathan Jackson
True Style: The History & Principles of Classic Menswear
No full textG. Bruce Boyer, men’s fashion editor and author of True Style: The History & Principles of Classic Menswear, discussed contemporary men’s dress and its history, styles, principles, and trends. He was joined by Pulitzer Prize- winning journalist Jonathan Capehart; New York Times cultural reporter Guy Trebay, and Michael Bastian; and MFIT Deputy Director Patricia Mears
Paranoia and irony in the Anglophone dectective narrative and the novels of Umberto Eco
No full textThe thesis provides a reading of Umberto Eco's three novels, The Name of the
Rose, Foucault's Pendulum, and The Island of the Day Before, that, while it
acknowledges the importance of the Italian literary tradition in which they stand, also
seeks to explain why their author appeals so frequently to literary models outside
Italy, and in particular the Anglo-American detective genre.
Chapter One explains Eco's relationship to the development of Italian literature
through his lifetime. It is noted that Eco is beginning, both in his semiotics and his
fiction, from a position where post-structuralism has been extensively explored by
neo-avant-gardew riters. Eco positions himself alongsides uchw riters as Italo Calvino
and Jorge Luis Borges, who wish to explore the ludic possibilities of working within
structures, while all the time acknowledging the epistemological limitations of so
doing. Eco's chosen structure, more often than not, is the highly defined genre of
the detective story.
From here, the following chapters engage in close readings of the three novels,
with particular emphasis on The Name of the Rose and Foucault's Pendulum,
demonstrating that they explore problems of interpretation central to the detective
narrative. In doing this, they display an intimate knowledge of generic developments
within the detective tradition, and of the philosophical and aesthetic uses made of the
genre by other writers. The embedding of intertextual references to other detective
narratives within Eco's novels is an important factor, as they come together to form
a narrative of epistemological inquiry that itself follows Eco's philosophical progress
through the years. In short, the novels, inter alia, map a systematic inquiry into the
possibility of systematic inquiry. They reserve the space to engage in such an ironic
and self-referential project precisely through their fictionality
Jonathan Safran Foer’s Tree of Codes: book design and digital sculpturing
No full textThe intricate literary experiment Tree of Codes, in which American author Jonathan Safran Foer reworks a story originally written by Jewish-Polish writer Bruno Schulz, enforces a haptic as well as textual experience of the destruction caused during the Shoah. At the same time, it re-evaluates processes of writing, book-making, and reading, showing the interactive traits and possibilities of the ‘classic’ material book as it inserts itself in a medial context determined by digital and computational techniques
The sentiments of a Church-of-England man : a study of Swift's politics
No full textThis contextualist study re-examines the contested critical
question of Jonathan Swift's political character. It is
concerned with the historical meaning of Swift's texts
and attempts to recover their original political impact.
Politically-literate contemporaries claimed to read Jacobite
Tory politics in Swift's texts. Rather than dismiss the
judgement of Swift's contemporaries, this study asks whether
there is anything about Swift's political writing in polemical
context that could have led contemporaries to construe
the politics of his texts as Jacobite Tory. The conclusion
this study reaches is that aspects of Swift's political
rhetoric are consonant with Tory and Jacobite polemic.
While contesting current conceptions of Swift as a Whig,
this study offers a partial revision of that scholarship
which describes Swift as a non-Jacobite Tory.
The thesis is based on an analysis of Swift's prose, poetry
and correspondence and contemporary (mainly printed) sources
books, pamphlets, poems on affairs of state and newspapers.
Some new or neglected polemical contexts and analogues
for Swift's works are suggested. Chapter 1 considers some
of the problems and contested issues in interpretation
of Swift's political biography and writing. Chapter 2
witnesses Swift's combination of High Church attitudes
with a radical political critique of Whig establishment.
Swift is read in juxtaposition with Jacobite Tory authors
such as George Granville, Lord Lansdowne. Chapter 3 relocates
A Tale of a Tub in historical context to reveal the satire's
relation to High Church Tory polemical languages. Chapter
4 discusses the disaffected Tory aspect of Gulliver's
Travels. Chapter 5 attempts to register the complexity
of the textual evidence of Swift's attitude to Jacobitism.
Detailed attention is given to his politically-revealing
attitudes to the Dutch. A coda briefly describes Swift's
discontent with the Revolution settlement, examines this
Church-of-England Man's sentiments on the crucial ideological
issue of resistance, and suggests the importance of Hugo
Grotius in Swift's political thought
Phytoecdysteroids: understanding their anabolic activity
No full textPhytoecdysteroids, polyhydroxylated ketosteroids, are the plant analogues of insect growth hormones. Although their role in insect molting is well characterized, their function in plants is less clear. Lacking the properties of classic plant hormones, phytoecdysteroids may be involved in plant growth and defense. One of the main benefits of phytoecdysteroids may be their therapeutic effects on mammals, including humans. Their claimed medicinal properties include anabolic, adaptogenic, hepatoprotective, and hypoglycemic activity. Although ethnobotanical use has been supported by some evidence, the research is quite limited, lacking the scientific rigor necessary to be convincing.
Two ecdysteroid containing plants, Ajuga turkestanica, and Spinacia olearaceae (Spinach), were selected as beneficial sources of phytoecdysteroids. Cultivation, analysis of ecdysteroid content, and characterization of anabolic activity were performed to support future medicinal use.
Phytoecdysteroids' anabolic activity, one of their most interesting properties due to the claimed lack of androgenic effect, was studied. Anabolic activity was confirmed in animal studies and a cellular model of skeletal muscle. The cellular model was used to characterize ecdysteroids' effect on protein incorporation and to elucidate the signal transduction pathway involved. Ecdysteroid's lack of androgenic activity was confirmed in vivo and in vitro, with ecdysteroids showing no specific binding to the androgen receptor.
Identification of mammalian nuclear receptors homologous with the insect nuclear ecdysone receptor led to binding and activation assays of potential receptors using ecdysteroids. The discovery of a lesser known membrane bound G Protein Coupled Receptor (GPCR) insect ecdysone receptor, DoEcR, suggested the existence of a hypothetical mammalian membrane bound GPCR ecdysone receptor.
Use of specific inhibitors supported the involvement of G protein signaling, Phospholipase C (PLC), Inositol Phosphate 3 Receptor (IP3R), and Akt. Ecdysteroid stimulated activation of Akt confirmed its role in the anabolic effect. Ecdysteroid generated increases in intracellular calcium were also characterized, with the rapid flux in Ca2+ linked with Akt activation and anabolic activity. The evidence produced suggests the involvement of a putative mammalian GPCR ecdysteroid receptor mediating the anabolic effect through the rapid activation of the PLC/IP3R pathway, generating Ca2+ flux which leads to activation of the Phosphoinositide 3 Kinase/Akt pathway, eventually causing increases in protein incorporation.Ph.D.Includes bibliographical references (p. 131-142)by Jonathan Isaac Gorelick-Feldma
An Open Framework for Integrating Widely Distributed Hypermedia Resources
No full textThe success of the WWW has served as an illustration of how hypermedia functionality can enhance access to large amounts of distributed information. However, the WWW and many other distributed hypermedia systems offer very simple forms of hypermedia functionality which are not easily applied to existing applications and data formats, and cannot easily incorporate alternative functions which would aid hypermedia navigation to and from existing documents that have not been developed with hypermedia access in mind. This paper describes the extension to a distributed environment of the open hypermedia functionality of the Microcosm system, which is designed to support the provision of hypermedia access to a wide range of source material and application, and to offer straightforward extension of the system to incorporate new forms of information access
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