Studies in bacterial phosphotriesterase evolution, dynamics, and engineering

the author deposited 12/06/201

What Moves Yields in Australia?

In this paper, we measure how the fixed-interest market in Australia assesses and responds to new economic information. We use high-frequency data, precise announcement times and market-based forecasts to measure the reaction of bill and bond yields to news. The period covered is from January 1994 to September 1997. We find that announcements about US economic news have had a large impact on yields in Australia – especially bond yields. Of the domestic announcements, the market responds to: monetary policy announcements, the CPI, the labour force and AWOTE, as well as a range of other economic statistics. We also find that the fixed-interest market seems to distinguish between the information contained in different economic announcements and that traders systematically respond to the size and direction of any unanticipated component of these announcements. The results suggest that the market perceives that information on prices, employment and wages is more important in the Reserve Bank’s decisions about monetary policy than are other indicators of economic activity. Taken in sum, the results also suggest some consistency of response to news in the fixed-interest market in Australia.news; economic announcements; financial markets; interest rates

Tell Khaiber: An administrative centre of the Sealand period

Excavations at Tell Khaiber in southern Iraq by the Ur Region Archaeological Project have revealed a substantial building (hereafter the Public Building) dating to the mid-second millennium b.c. The results are significant for the light they shed on Babylonian provincial administration, particularly of food production, for revealing a previously unknown type of fortified monumental building, and for producing a dated archive, in context, of the little-understood Sealand Dynasty. The project also represents a return of British field archaeology to long-neglected Babylonia, in collaboration with Iraq's State Board for Antiquities and Heritage. Comments on the historical background and physical location of Tell Khaiber are followed by discussion of the form and function of the Public Building. Preliminary analysis of the associated archive provides insights into the social milieu of the time. Aspects of the material culture, including pottery, are also discussed

Optical activity of the super-atom molecular orbital (SAMO) states in Li@ C60+ conformers

Super Atom Molecular Orbitals (SAMOs) are electronic excited states found in fullerenes in which an electron is excited to one or, more generally, several virtual orbitals with hydrogen like character. The photoexcitation mechanism of the SAMO states strongly depends on the symmetry of the fullerene. For instance the SAMOs of the spherical C60 fullerene are not optically active while breaking the symmetry by adding a dopant can make the SAMO states optically active. In this proceeding we investigate the optical activity of the SAMO states in several conformers of the Li@C60+ fullerene and we show that the position of the lithium atom inside the fullerene cage strongly affects the computed oscillator strengths and transition dipole moments of the SAMO states

Visible and ultraviolet photoelectron spectroscopy of fullerenes using femtosecond laser pulses

Photoelectron spectra are presented for C60 excited with fs pulses of wavelengths 532 and 267 nm. The spectra indicate a quick redistribution of the excitation energy. Excitation of SAMO states is observed with 532 nm excitation, but due to the relatively large photon energy of the 267 nm pulses, these orbitals are not populated for this wavelength

Sublimation of Li@C60

R.S. acknowledges financial support from the Scottish Funding Council thorugh SRD-Grant (HR07003) and H.J.C. from an EPSRC DTG studentship (EP/M508214/1).Experiments that probe the fundamental properties of endohedral fullerenes often require the preparation of molecular beams or thin films of the neutral molecules. It is challenging to cleanly sublime this class of molecules without producing some thermal degradation. We report combined gas phase and scanning tunnelling microscopy studies that probe the thermal decay of commercial [Li+C60]PF6- in a quartz ampoule and provide treatment conditions that will allow the sublimation of intact, neutral Li@C60 accompanied by a well-characterised component of neutral C60. The decay of the material at appropriate temperatures can be modelled with the assumption of a second order decay process in the oven yielding Arrhenius parameters that can predict the ratio of Li@C60 to C60 in the sublimed material.Publisher PDFPeer reviewe

On competitive gas adsorption and absorption phenomena in thin films of ionic liquids

Although there has been a lot of interest in materials that feature thin films of ionic liquids on the surface of porous materials, fundamental understanding of gas–liquid interfacial processes is still lacking, hindering the development of novel adsorbents and adsorption models for practical applications. Herein, we investigated the mechanism of competitive gas adsorption on and absorption in thin films of ionic liquid, [BMIM]+[PF6]−, exposed to the gas phase containing carbon dioxide and nitrogen. To estimate correct quantitative contributions of these processes, we performed classical molecular dynamics simulations of the gas–liquid interfacial systems. Adsorption of gases proceeds through the formation of an adsorbed gas layer on the surface of the ionic liquid and partial dissolution of the gas in the bulk liquid phase. To characterize the competition between these two processes we introduced a parameter, the equipartition thickness of the film of ionic liquid, which relates the contributions of gas dissolved in the liquid phase and gas adsorbed on the surface of the film to the total amount adsorbed. At a given temperature, the equipartition thickness is constant for a specific gas-ionic liquid pair in the Henry's law regime, where uptake is proportional to the applied gas pressure. Through the combination of computational and available experimental studies, we propose how a single property, the equipartition thickness, may govern the development of task-specific porous materials and predict their performance as well as thermodynamics of gas adsorption