Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

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Self-assembled monolayers of thiolates on metals as a form of nanotechnology.

About Supramolecular Assemblies of π-Conjugated Systems

Graphenes as potential material for electronics.

The application of self-assembled hosts as "molecular flasks" has precipitated a surge of interest in the reactivity and properties of molecules within well-defined confined spaces. The facile and modular synthesis of self-assembled hosts has enabled a variety of hosts of differing sizes, shapes, and properties to be prepared. This Review briefly highlights the various molecular flasks synthesized before focusing on their use as functional molecular containers--specifically for the encapsulation of guest molecules to either engender unusual reactions or unique chemical phenomena. Such self-assembled cavities now constitute a new phase of chemistry, which cannot be achieved in the conventional solid, liquid, and gas phases.

Functional Molecular Flasks : New Properties and Reactions within Discrete, Self-Assembled Hosts

Disc-shaped objects can be induced to form columnar assemblies whether their scale is tens of Angstroms (molecular), tens of nanometers (macromolecular or supramolecular), hundreds of nanometers (colloidal) or tens of microns (‘manufactured’ platelets). The last couple of years have seen rapid progress in the development of conducting columnar systems and in controlling the orientation of discotic mesophases. The first serious commercial development has also emerged. Fuji Film Company has perfected and marketed optical compensating films based on cross-linked nematic discogens with controlled hybrid orientation.

Discotic liquid crystals 25 years on

The main applications and potential applications of discotic liquid crystals are reviewed. At present their most important application is in the manufacture of optical compensating films; films that increase the angle of view in liquid crystal displays. Their use as lubricants and lubricant additives also seems to be developing into a significant area. Progress in the development of other applications is reviewed, including field effect transistors, light-emitting devices, photovoltaic devices and the electronic nose. This is a relatively young field and, as with any new class of materials, it takes time to find applications where their unique properties present a real advantage. However, discotic liquid crystals are already having a significant impact.

Liquid crystals that affected the world: discotic liquid crystals

Mechanism of charge transport in discotic liquid crystals.

Recently, it has been shown that a new class of quasi‐one‐dimensional conductors can be created by doping discotic liquid crystals with appropriate oxidants. This paper reports the elucidation of the mechanism of conduction in these new materials. In particular, the ac conductivity of 2,3,6,7,10,11‐hexahexyloxytriphenylene (HAT6) doped with the Lewis acid AlCl3, has been measured as a function of frequency (10−3–107 Hz), and temperature in its crystalline solid (K), hexagonal discotic liquid crystal (Dho), and isotropic liquid (I) phases. In all three phases the conductivity is independent of frequency at low frequencies, but shows a power law dependence on frequency [σ(ω)∼ωs, s∼0.7–0.8] at higher frequencies. This behavior is characteristic of charge carrier transport by a hopping mechanism. The conductivity data have been analyzed in terms of the Scher and Lax theory to obtain the parameters describing this process. In macroscopically aligned K and Dho phases, the conductivity measured along the column ...

Mechanism of quasi‐one‐dimensional electronic conductivity in discotic liquid crystals

The synthesis of discotic liquid crystal materials based on the triphenylene core normally involves the preparation of hexahydroxytriphenylene. This has traditionally been accomplished by a chloranil promoted trimerization of 1,2-dimethoxy-benzene followed by demethylation of the hexamethoxytriphenylene produced. Hexahydroxytriphenylene is subsequently alkylated to give the required derivative. The overall yield of this three step procedure is low and it is difficult to perform on a large scale. It is herein shown that a modified procedure using iron III chloride instead of chloranil yields hexa-alkoxytriphenylenes in a single step. The reaction is high yielding and can be performed on a large scale. This also provides a better route than those currently available for making the unsymmetrically substituted tri-phenylenes required in the synthesis of polymeric discotic liquid crystals. Some related elaborations of the triphenylene nucleus are also discussed.

Richard J. Bushby

Papers

Discotic liquid crystals 25 years on

Liquid crystals that affected the world: discotic liquid crystals

Mechanism of charge transport in discotic liquid crystals.

Mechanism of quasi‐one‐dimensional electronic conductivity in discotic liquid crystals

The synthesis of triphenylene-based discotic mesogens New and improved routes