Aziridine-Metathesis based Approaches to Alkaloid Synthesis

The aim of the project is to synthesise (-)-morphine utilising aziridine and metathesischemistry. The thesis is divided into three chapters.Chapter 1 provides brief reviews on the subjects of total synthesis of morphine; ringrearrangementmetathesis (RRM) and regioselective ring-opening of aziridines.Chapter 2 focuses on the research findings in the past three years. Two routes, A and B,were investigated in attempts to synthesise morphine (Scheme 1). In route A, sulfonylcyclopentene II was prepared from ring-closing metathesis of a diene precursor, whichwas synthesised from lithiated cinnamylsulfone and butadiene monoxide. Subsequently,RRM reactions of several [alpha]-SO2Ph allyl derivatives of II were investigated and someinteresting results were obtained. The synthesis of 2,3-trans vinylaziridine III wasachieved in seven steps beginning with a Grignard reaction of (4-methoxyphenyl)magnesium bromide with butadiene monoxide. Subsequently, somehighly regioselective ring-opening reactions of III with sulfur-stabilised anionicnucleophiles were achieved. However, in an attempt to synthesise compound I from IIand III, no reaction was observed. This led to the investigation of route B, in which fivemethods for the synthesis of compound IV were investigated. The practical approachdeployed a novel Al-mediated substitution of the 4-tosyl group of the tosyltetrahydropyridine counterpart of IV, prepared from V and III, with a phenylthio group.Chapter 3 provides the experimental details and characterisation data.Imperial Users onl

The effect of social security payroll tax reductions on employment and wages: an evaluation of the 2003 French reform

public policy evaluation, payroll tax cuts, labour cost, semi-parametric estimations

The 3.3 micron emission feature: Map of the galactic disk, 10 deg less than 1 less than 35 deg, - 6 deg less than b less than 6 deg

The 3.3 micron aromatic feature has been detected in the diffuse galactic emission with the AROME balloon-borne instrument. The results are presented in the form of an map of the 3.3 micron feature's intensity. The AROME instrument consists in a Cassegrain telescope with wobbling secondary mirrors and a liquid/solid nitrogen cooled photometer. The instrumental output is modified by the impulse response of the system. So the galactic surface brightness was restored in Fourier space by an inverse optimal filtering. The map of the feature's intensity is presented for a region of galactic coordinates. All the known H II giant molecular cloud complexes are visible in the 3.3 micron feature emission showing a good correlation with the infrared dust emission

Growth, reproduction and feeding biology of Malapterurus electricus (Gmelln,1789) in lower Benue River, Nigeria

The reproductive biology, food and feeding habit and growth pattern of Malapterurus electricus (Gmelin) were investigated using a sample of 50 males and 67 females collected from the River Benue in Makurdi. The mean standard lengths of males and females were 18.9 ~ 1.49cm and 17. 8 ± 0.43 cm respectively, while the mean total weights were 195.7 ± 50.4g for males and 130.1 ± 21.7gfor females. The mean condition factors were 2.32 ± 0.02 (males) and 2.09 ± 0.01 (females). Malapterurus electricus in River Benue exhibited isometric growth and their main food items were fish and arthropod. The species attained sexual maturity at a mean standard length of 16.7 ± 2.3cmin males and 17.4 ± 3.2cm in females. The mean fecundity was 2331 ± 970.2 eggs. The results were discussed in relation to the need for a full understanding of the basic biology of this important ornamental fish

Physio-Chemical and Mechanical Behaviour of(Pinussylvestris) as Binders on Foundry Core Strength

The mechanical potential of sand core binders made withPinussylvestris has been examined. Ota silica base sand bonded with 6% of cassava starch in admixed proportion of Pinussylvestris was tested for tensile, compressive strength and permeability to establish the binding efficiency. Tensile strength of the green baked core were oven baked at 50°C, 100°C, 150°C and 200°C.The cylindrically shaped permeability specimens were tested with permeability meter. Study revealed thatPinussylvestris showed an improve properties at 6% cassava starch at 200°C

The HIRLAM fast radiation scheme for mesoscale numerical weather prediction models

This paper provides an overview of the HLRADIA shortwave (SW) and longwave (LW) broadband radiation schemes used in the HIRLAM numerical weather prediction (NWP) model and available in the HARMONIE-AROME mesoscale NWP model. The advantage of broadband, over spectral, schemes is that they can be called more frequently within the model, without compromising on computational efficiency. In mesoscale models fast interactions between clouds and radiation and the surface and radiation can be of greater importance than accounting for the spectral details of clear-sky radiation; thus calling the routines more frequently can be of greater benefit than the deterioration due to loss of spectral details. Fast but physically based radiation parametrizations are expected to be valuable for high-resolution ensemble forecasting, because as well as the speed of their execution, they may provide realistic physical perturbations. Results from single-column diagnostic experiments based on CIRC benchmark cases and an evaluation of 10 years of radiation output from the FMI operational archive of HIRLAM forecasts indicate that HLRADIA performs sufficiently well with respect to the clear-sky downwelling SW and longwave LWfluxes at the surface. In general, HLRADIA tends to overestimate surface fluxes, with the exception of LW fluxes under cold and dry conditions. The most obvious overestimation of the surface SW flux was seen in the cloudy cases in the 10-year comparison; this bias may be related to using a cloud inhomogeneity correction, which was too large. According to the CIRC comparisons, the outgoing LW and SW fluxes at the top of atmosphere are mostly overestimated by HLRADIA and the net LW flux is underestimated above clouds. The absorption of SW radiation by the atmosphere seems to be underestimated and LW absorption seems to be overestimated. Despite these issues, the overall results are satisfying and work on the improvement of HLRADIA for the use in HARMONIE-AROME NWP system is ongoing. In a HARMONIE-AROME 3-D forecast experiment we have shown that the frequency of the call for the radiation parametrization and choice of the parametrization scheme makes a difference to the surface radiation fluxes and changes the spatial distribution of the vertically integrated cloud cover and precipitation.Peer reviewe

Aziridine–Metathesis based Approaches to Alkaloid Synthesis

The aim of the project is to synthesise (–)-morphine utilising aziridine and metathesis chemistry. The thesis is divided into three chapters. Chapter 1 provides brief reviews on the subjects of total synthesis of morphine; ringrearrangement metathesis (RRM) and regioselective ring-opening of aziridines. Chapter 2 focuses on the research findings in the past three years. Two routes, A and B, were investigated in attempts to synthesise morphine (Scheme 1). In route A, sulfonyl cyclopentene II was prepared from ring-closing metathesis of a diene precursor, which was synthesised from lithiated cinnamylsulfone and butadiene monoxide. Subsequently, RRM reactions of several α-SO2Ph allyl derivatives of II were investigated and some interesting results were obtained. The synthesis of 2,3-trans vinylaziridine III was achieved in seven steps beginning with a Grignard reaction of (4- methoxyphenyl)magnesium bromide with butadiene monoxide. Subsequently, some highly regioselective ring-opening reactions of III with sulfur-stabilised anionic nucleophiles were achieved. However, in an attempt to synthesise compound I from II and III, no reaction was observed. This led to the investigation of route B, in which five methods for the synthesis of compound IV were investigated. The practical approach deployed a novel Al-mediated substitution of the 4-tosyl group of the tosyl tetrahydropyridine counterpart of IV, prepared from V and III, with a phenylthio group. Chapter 3 provides the experimental details and characterisation data

The ALADIN system and its canonical model configurations AROME CY41T1 and ALARO CY40T1

The ALADIN System is a numerical weather prediction (NWP) system developed by the international ALADIN consortium for operational weather forecasting and research purposes. It is based on a code that is shared with the global model IFS of the ECMWF and the ARPEGE model of Meteo-France. Today, this system can be used to provide a multitude of high-resolution limited-area model (LAM) configurations. A few configurations are thoroughly validated and prepared to be used for the operational weather forecasting in the 16 partner institutes of this consortium. These configurations are called the ALADIN canonical model configurations (CMCs). There are currently three CMCs: the ALADIN baseline CMC, the AROME CMC and the ALARO CMC. Other configurations are possible for research, such as process studies and climate simulations. The purpose of this paper is (i) to define the ALADIN System in relation to the global counterparts IFS and ARPEGE, (ii) to explain the notion of the CMCs, (iii) to document their most recent versions, and (iv) to illustrate the process of the validation and the porting of these configurations to the operational forecast suites of the partner institutes of the ALADIN consortium. This paper is restricted to the forecast model only; data assimilation techniques and postprocessing techniques are part of the ALADIN System but they are not discussed here