Preparation and reactions of polymers and copolymers of 2-methylbut-1-en-3-one, and related studies.

Poly(2-methylbut-1-en-3-one) was prepared by bulk polymerisation with azobisisobutyronitrile as initiator. Six copolymers of 2-methylbut-l-en-3-one and styrene in various ratios were prepared similarly. The homopolymer on treatment in solution with hydrogen chloride gave a product in which water had been condensed from neighbouring acetyl side-chains to give a polymer containing series of conjugated double bonds. The homopolymer was oxidised with aqueous alkaline potassium permanganate to give a copolymer of methacrylic acid and 3-niethylbut-3-en-2-oxo-1-oic acid. The homopolymer was reduced with lithium aluminium hydride in tetrahydrofuran to give a product containing 70% of secondary alcohol groups. The homopolymer was treated with hydroxylamine hydrochloride in pyridine to give a product containing oxime groups, oxime anhydride groups and unreacted ketone groups. The 1:2-copolymer was brominated to give a product in which all the methyl ketone side-chains had been converted to bromomethyl ketone side-chains. The brominated 1:2-copolymer was reacted with thiourea to give a copolymer in which all the bromine had been replaced by isothiourea groups. Where possible low molecular weight analogues of the polymers were prepared, based on 2,2-dimethylbutan-3-one. The infra-red spectra of the polymers and polymeric derivatives were compared with those of the low molecular weight analogues. The reactivities of the above polymeric compounds are discussed in relation to the characteristics of the corresponding molecular models

Modelling potential drivers of fish kill events in Sulaibikhat Bay, Kuwait

Water Qualit

The Planetary Nebulae Population in the Nuclear Regions of M31: the SAURON view

Following a first study of the central regions of M32 that illustrated the power of integral-field spectroscopy (IFS) in detecting and measuring the [O III]{\lambda}5007 emission of PNe against a strong stellar background, we turn to the very nuclear PN population of M31, within 80 pc of its centre. We show that PNe can also be found in the presence of emission from diffuse gas and further illustrate the excellent sensitivity of IFS in detecting extragalactic PNe through a comparison with narrowband images obtained with the Hubble Space Telescope. We find the nuclear PNe population of M31 is only marginally consistent with the generally adopted form of the PNe luminosity function (PNLF). In particular, this is due to a lack of PNe with absolute magnitude M5007 brighter than -3, which would only result from a rather unfortunate draw from such a model PNLF. We suggest that the observed lack of bright PNe in the nuclear regions of M31 is due to a horizontal-branch population that is more tilted toward less massive and hotter He-burning stars, so that its progeny consists mostly of UV-bright stars that fail to climb back up the asymptotic giant branch (AGB) and only of few, if any, bright PNe powered by central post-AGB stars. These results are also consistent with recent reports on a dearth of bright post-AGB stars towards the nucleus of M31, and lend further support to the idea that the metallicity of a stellar population has an impact on the way the horizontal branch is populated and to the loose anticorrelation between the strength of the UV-upturn and the specific number of PNe that is observed in early-type galaxies. Finally, our investigation also serves to stress the importance of considering the same spatial scales when comparing the PNe population of galaxies with the properties of their stellar populations.Comment: 11 pages, 10 figures, accepted for publication on Monthly Notices of the Royal Astronomical Societ

Probing the stellar populations of early-type galaxies: the SAURON survey

The SAURON project will deliver two-dimensional spectroscopic data of a sample of nearby early-type galaxies with unprecedented quality. In this paper, we focus on the mapping of their stellar populations using the SAURON data, and present some preliminary results on a few prototypical cases.Comment: 12 pages, 6 figures. ASP Conference, Galaxies: the Third Dimension, Cozumel. Version with higher resolution figures available at http://www-obs.univ-lyon1.fr/eric.emsellem/papers/cozumel_emsellem.ps.g

Morphology and kinematics of the ionised gas in early-type galaxies

We present results of our ongoing study of the morphology and kinematics of the ionised gas in 48 representative nearby elliptical and lenticular galaxies using the SAURON integral-field spectrograph on the 4.2m William Herschel Telescope. Making use of a recently developed technique, emission is detected in 75% of the galaxies. The ionised-gas distributions display varied morphologies, ranging from regular gas disks to filamentary structures. Additionally, the emission-line kinematic maps show, in general, regular motions with smooth variations in kinematic position angle. In most of the galaxies, the ionised-gas kinematics is decoupled from the stellar counterpart, but only some of them present signatures of recent accretion of gaseous material. The presence of dust is very common in our sample and is usually accompanied by gas emission. Our analysis of the [OIII]/Hbeta emission-line ratios, both across the whole sample as well as within the individual galaxies, suggests that there is no unique mechanism triggering the ionisation of the gas.Comment: 8 pages, 2 figures, submitted to "Adaptive Optics-Assisted Integral-Field Spectroscopy", Rutten R.G.M., Benn C.R., Mendez J., eds., May 2005, La Palma (Spain), New Astr. Rev. For full resolution PS, see http://www.strw.leidenuniv.nl/~jfalcon/JFB_AOmeeting_color_hires.ps.g

SAURON Observations of Disks in Early-Type Galaxies

We briefly describe the SAURON project, aimed at determining the intrinsic shape and internal dynamics of spheroids. We focus here on the ability of SAURON to identify gaseous and stellar disks and to measure their morphology and kinematics. We illustrate some of our results with complete maps of NGC3377, NGC3623, and NGC4365.Comment: 4 pages, 4 figures (newpasp.sty). To appear in ASP Conf. Series "Galaxy Disks and Disk Galaxies", eds. J.G. Funes S.J. & E.M. Corsini. Version with full resolution images available at http://www.strw.leidenuniv.nl/~bureau/pub_list.htm

Littoral undersea warfare: a case study in process modelling for functionality and introperability of complex systems

The goal of this investigation is to demonstrate the application of a process modelling approach to architect a System of Systems (SoS) capable of conducting Anti-Submarine Warfare (ASW) operations projecting to the year 2025. Process modelling is a methodology for architectural analysis for complex systems whose operation is characterised by ‘processes’ whose sequential execution may be scaled-up to understand overall system behaviour. It is ideally suited to address complexity and interoperability issues of an ASW SoS. New contributions of this work include the successful implementation of a process modelling approach to architect an ASW SoS and a cohesive set of results analysing its operation with future projections to the year 2025. We believe this work may serve as a foundation for future systems engineering research addressing interoperability and performance of complex systems whose function is closely tied to time-dependent processes, with particular application to military and security systems

Supermassive black holes from OASIS and SAURON integral-field kinematics

Supermassive black holes are a key element in our understanding of how galaxies form. Most of the progress in this very active field of research is based on just ~30 determinations of black hole mass, accumulated over the past decade. We illustrate how integral-field spectroscopy, and in particular our OASIS modeling effort, can help improve the current situation.Comment: 4 pages, 2 figures, LaTeX. To appear in the proceedings of IAU Symposium 245 "Formation and Evolution of Galaxy Bulges", M. Bureau, E. Athanassoula, and B. Barbuy, ed

Fast and Slow Rotators: The build-up of the Red Sequence

Using the unique dataset obtained within the course of the SAURON project, a radically new view of the structure, dynamics and stellar populations of early-type galaxies has emerged. We show that galaxies come in two broad flavours (slow and fast rotators), depending on whether or not they exhibit clear large-scale rotation, as indicated via a robust measure of the specific angular momentum of baryons. This property is also linked with other physical characteristics of early-type galaxies, such as: the presence of dynamically decoupled cores, orbital structure and anisotropy, stellar populations and dark matter content. I here report on the observed link between this baryonic angular momentum and a mass sequence, and how this uniquely relates to the building of the red sequence via dissipative/dissipationless mergers and secular evolution.Comment: 4 pages, 1 figure. To appear in the Proceedings of IAU Symposium 245 "Formation and Evolution of Galaxy Bulges", Eds M. Bureau, E. Athanassoula, and B. Barbu