Empirical line lists and absorption cross sections for methane at high temperature

Hot methane is found in many "cool" sub-stellar astronomical sources including brown dwarfs and exoplanets, as well as in combustion environments on Earth. We report on the first high-resolution laboratory absorption spectra of hot methane at temperatures up to 1200 K. Our observations are compared to the latest theoretical spectral predictions and recent brown dwarf spectra. The expectation that millions of weak absorption lines combine to form a continuum, not seen at room temperature, is confirmed. Our high-resolution transmittance spectra account for both the emission and absorption of methane at elevated temperatures. From these spectra, we obtain an empirical line list and continuum that is able to account for the absorption of methane in high temperature environments at both high and low resolution. Great advances have recently been made in the theoretical prediction of hot methane, and our experimental measurements highlight the progress made and the problems that still remain.Comment: 9 pages, 5 figures and 3 tables. For associated online data see http://dx.doi.org/10.1088/0004-637X/813/1/1

Students' views on what aids their learning of school science in Lagos state, Nigeria

In Nigeria, school science education is believed to be impeded by multiple issues, in part resulting from limitations on funding, but there is a dearth of research that attends to the views of learners themselves. The aim of this study was to explore the views of secondary students in Lagos, Nigeria about the school science teaching they received. A multiple case study research design was employed and semi-structured individual (n = 26) and group (n = 4) interviews were undertaken with 14–17-year-old students from four non-fee-paying, mixed-sex public secondary schools. Sampling was purposive, so that the four schools were fairly typical of secondary schools in Lagos, while the interviewed students were preparing to study science at university and follow science career pathways and included both students who were engaged in terms of their participation in class and those who appeared withdrawn. Analysis was undertaken within a theoretical framework derived partly from Vygotsky’s socio-cultural theory of teaching and learning and partly from Watkins’ theories of learning. Students articulated how certain teaching methods, such as learning with and from others in group work, using familiar examples as applications of knowledge and undertaking practical work, were felt to aid their learning of science. These views align with the sorts of approaches to teaching and learning advocated by both Vygotsky and Watkins. It was concluded that there exists quite a gap between what the students said were effective ways of their being taught science and what were often their experiences. Some of the differences are to do with funding shortages but others are to do with pedagogy and terminal assessment

Global shocks, economic growth and financial crises: 120 years of New Zealand experience

We identify the timing of currency, banking crises and sudden stops in New Zealand from 1880 to 2008, and consider the extent to which empirical models can explain New Zealand’s crisis history. We find that the cross country evidence on the determinants of crises fits New Zealand experience reasonably well. A number of the risk factors that correlate with crises internationally–such as domestic imbalances, external debt, and currency mismatches–were elevated for New Zealand when the country had more frequent crises and have improved in the recent (more stable) period. However, a time-series analysis of New Zealand growth over 120 years shows that global factors–such as the US growth rate and terms of trade–explain New Zealand growth fairly well, and that crisis dummy variables do not have significant additional explanatory power. This suggests that having sound institutions and policies may help avoid severe domestic crises, but will not be sufficient to avoid the domestic economic impact of the global business cycle.

Towards the C20-C32 fragment of the phorboxazoles

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Analytical and experimental studies of vehicle pollution dispersion

Using a dual approach of wind tunnel experimentation and the development of an analytical model, the dispersion of pollutants from road vehicles has been investigated. A series of novel tests were conducted in an environmental wind tunnel which looked at the dispersion of propane in the wake of a 1=50th scale model of a lorry which was fired across the wind tunnel using a special rig. Time histories of concentration and air flow were taken as the lorry sped across the tunnel. Two experimental scenarios were investigated. The first, a simulation of a typical rural boundary layer, confirmed the existence of a wake behind the moving lorry. Concentration measurements revealed that the dispersion was largely Gaussian in nature and that at low cross wind speeds the vehicle-induced turbulence was the dominant mixing effect. Measurements were taken as the lorry passed along a model of an idealized urban street canyon. Time histories for individual firings exhibited two peaks as the propane was swept around the canyon in the resident vortex. Ensemble averages of several firings allowed a quantitative assessment of the rate of dispersal from the canyon to be made. A computer model has been developed which predicts the dispersion of vehicular pollutants in both the rural and the urban street canyon environments. The model, based around the Gaussian Puff Method, extends the range of applicability of earlier models in several areas. It is a transient model which enables the investigation of traffic congestion and non-steady above canyon wind fields. It is also the first model to include individual vehicles as sources of both pollutant and turbulence. A detailed sensitivity study is presented, followed by an application of the model which attempts to predict probability distributions of pollutant in a street canyon. Finally, a comparison between the analytical model and the experimental program is presented which demonstrates that the model is capable of modelling a real situation to a good degree of accuracy but also demonstrates that further validation is required

The Mirrored City: creating claustrophobia and pace in overpopulation through prose

Andrew Lamprell is a jaded journalist living in London some hundred years in the future. He describes himself as a ‘world turner’ and holds little value in his job or society. He has one aspiration, Esme Harper, a celebrity news anchor, who he has become obsessed with. He wishes to woo her and escape to space with the money he has saved from years of a minimalist lifestyle. Andrew is given an exclusive scoop on an underground medical centre by nurse and long-time friend Elizabeth Ruby. The medical centre is operated by a young doctor and a mysterious scarred man who can fly his sky-car out of the permitted zones, something Andrew thought was impossible. After writing the article on the untested drugs that are being sold to people the government have refused medical care to, he rests. The following morning, the article has been published and he has two tickets to Limbo X, the space station in between Earth and the colony on Mars. He soon discovers that the scarred man, Locke, has orchestrated his good fortune and wants something in return. Locke promises Andrew that he will get him Esme Harper, but only if he does as he says. Andrew complies, exploring areas of the country that he thought were uninhabitable. He helps Locke transfer a computer virus into the software of higher-members of society, which quickly spreads, giving Locke complete control of the city. The night before Andrew’s flight to Limbo X, Locke flies him to the London News Service, with a replicate of Esme Harper sitting in the front seat. Locke says he will give her to Andrew, but he refuses. Offended, Locke begins his anarchist plan early, setting off all the fire alarms of the city, cutting the power and the traffic system. Andrew leans over and crashes Locke’s car through a nearby building. Upon waking, Andrew sees the chaos unfolding below and uses the strong android in the passenger seat as a way of getting through the condensed crowds below. He reaches Esme Harper’s apartment, discovering it has been broken into. Three dead men are on the floor and Esme Harper is stood naked in the room. Exposed wires dangle from the insides of her thighs from the assault and a label on her back reads: property of LNS. She greets Andrew

Absolute Electron Scattering Cross Sections for the CF2 Radical

Using a crossed electron-molecular beam experiment, featuring a skimmed nozzle beam with pyrolytic radical production, absolute elastic cross sections for electron scattering from the CF2 molecule have been measured. A new technique for placing measured cross sections on an absolute scale is used for molecular beams produced as skimmed supersonic jets. Absolute differential cross sections for CF2 are reported for incident electron energies of 30–50 eV and over an angular range of 20–135 deg. Integral cross sections are subsequently derived from those data. The present data are compared to new theoretical predictions for the differential and integral scattering cross sections, as calculated with the Schwinger multichannel variational method using the static-exchange and static-exchange plus polarization approximations

Analytical and experimental studies of vehicle pollution dispersion

Using a dual approach of wind tunnel experimentation and the development of an analytical model, the dispersion of pollutants from road vehicles has been investigated. A series of novel tests were conducted in an environmental wind tunnel which looked at the dispersion of propane in the wake of a 1=50th scale model of a lorry which was fired across the wind tunnel using a special rig. Time histories of concentration and air flow were taken as the lorry sped across the tunnel. Two experimental scenarios were investigated. The first, a simulation of a typical rural boundary layer, confirmed the existence of a wake behind the moving lorry. Concentration measurements revealed that the dispersion was largely Gaussian in nature and that at low cross wind speeds the vehicle-induced turbulence was the dominant mixing effect. Measurements were taken as the lorry passed along a model of an idealized urban street canyon. Time histories for individual firings exhibited two peaks as the propane was swept around the canyon in the resident vortex. Ensemble averages of several firings allowed a quantitative assessment of the rate of dispersal from the canyon to be made. A computer model has been developed which predicts the dispersion of vehicular pollutants in both the rural and the urban street canyon environments. The model, based around the Gaussian Puff Method, extends the range of applicability of earlier models in several areas. It is a transient model which enables the investigation of traffic congestion and non-steady above canyon wind fields. It is also the first model to include individual vehicles as sources of both pollutant and turbulence. A detailed sensitivity study is presented, followed by an application of the model which attempts to predict probability distributions of pollutant in a street canyon. Finally, a comparison between the analytical model and the experimental program is presented which demonstrates that the model is capable of modelling a real situation to a good degree of accuracy but also demonstrates that further validation is required