Tropospheric reactions of the haloalkyl radicals formed from hydroxyl radical reaction with a series of alternative fluorocarbons

In the present assessment, the hydrogen containing halocarbons being considered as alternatives to the the presently used chlorofluorocarbons are the hydrochlorofluorocarbons (HCFCs) 123 (CF3CHCl2), 141b (CFCl2CH3), 142b (CF2ClCH3), 22 (CHF2Cl) and 124 (CF3CHFCl) and the hydrofluorocarbons (HFCs) 134a (CF3CH2F), 152a (CHF2CH3) and 125 (CF3CHF2). All of these HCFCs and HFCs will react with the hydroxyl (OH) radical in the troposphere, giving rise to haloalkyl radicals which then undergo a complex series of reactions in the troposphere. These reactions of the haloalkyl radicals formed from the initial OH radical reactions with the HCFCs and HFCs under tropospheric conditions are the focus here

Roger Atkinson’s reflections on David Hillson’s Risk Doctor briefing

Roger Atkinson's reflections on David Hillson's Risk Doctor briefin

Local density of states of a d-wave superconductor with inhomogeneous antiferromagnetic correlations

The tunneling spectrum of an inhomogeneously doped extended Hubbard model is calculated at the mean field level. Self-consistent solutions admit both superconducting and antiferromagnetic order, which coexist inhomogeneously because of spatial randomness in the doping. The calculations find that, as a function of doping, there is a continuous cross over from a disordered ``pinned smectic'' state to a relatively homogeneous d-wave state with pockets of antiferromagnetic order. The density of states has a robust d-wave gap, and increasing antiferromagnetic correlations lead to a suppression of the coherence peaks. The spectra of isolated nanoscale antiferromagnetic domains are studied in detail, and are found to be very different from those of macroscopic antiferromagnets. Although no single set of model parameters reproduces all details of the experimental spectrum in BSCCO, many features, notably the collapse of the coherence peaks and the occurence of a low-energy shoulder in the local spectrum, occur naturally in these calculations.Comment: 9 pages, 5 figure

Space|Time|Place : enabling participation in design research for higher education staff

This paper explores the value of design research to better inform design pedagogy in Higher Education. It describes a programme of initiatives aimed at giving staff involved in delivering undergraduate and postgraduate design courses the space, time and place to fully engage with practice-based design research and describes the results of that research. These initiatives aimed to address a perennial problem in design education in the UK. Although being actively involved in research is recognized at the highest levels as beneficial to better staff morale and resulting in better informed teaching, the daily pressures of working in Higher Education combine to restrict the very people who wish to engage with research from doing so. To retain the initial momentum Space/Time/Place provided, the staff established a Community of Practice (COP) ((Lave and Wenger)). The goal of a COP is to bring the peripheral members of the community into full participation within the community guided by more experienced peers who form the core group of the COP. The Space/Time/Place COP met to develop the initial discussions into bids to secure funding for further practice based research. The Community of Practice meetings were supplemented by the use of social media platforms. The strength of support the Space/Time/Place event and Community of Practice have engendered in the staff is undeniable. The outcomes of Space/Time/Place will be exhibited in a group exhibition and used by the authors to model and broker the impact of this approach to other lecturers across the department, faculty and University

Heterogeneous reactions of particulate matter-bound PAHs and NPAHs with NO3/N2O5, OH radicals, and O3 under simulated long-range atmospheric transport conditions: reactivity and mutagenicity.

The heterogeneous reactions of ambient particulate matter (PM)-bound polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) with NO3/N2O5, OH radicals, and O3 were studied in a laboratory photochemical chamber. Ambient PM2.5 and PM10 samples were collected from Beijing, China, and Riverside, California, and exposed under simulated atmospheric long-range transport conditions for O3 and OH and NO3 radicals. Changes in the masses of 23 PAHs and 20 NPAHs, as well as the direct and indirect-acting mutagenicity of the PM (determined using the Salmonella mutagenicity assay with TA98 strain), were measured prior to and after exposure to NO3/N2O5, OH radicals, and O3. In general, O3 exposure resulted in the highest relative degradation of PM-bound PAHs with more than four rings (benzo[a]pyrene was degraded equally well by O3 and NO3/N2O5). However, NPAHs were most effectively formed during the Beijing PM exposure to NO3/N2O5. In ambient air, 2-nitrofluoranthene (2-NF) is formed from the gas-phase NO3 radical- and OH radical-initiated reactions of fluoranthene, and 2-nitropyrene (2-NP) is formed from the gas-phase OH radical-initiated reaction of pyrene. There was no formation of 2-NF or 2-NP in any of the heterogeneous exposures, suggesting that gas-phase formation of NPAHs did not play an important role during chamber exposures. Exposure of Beijing PM to NO3/N2O5 resulted in an increase in direct-acting mutagenic activity which was associated with the formation of mutagenic NPAHs. No NPAH formation was observed in any of the exposures of the Riverside PM. This was likely due to the accumulation of atmospheric degradation products from gas-phase reactions of volatile species onto the surface of PM collected in Riverside prior to exposure in the chamber, thus decreasing the availability of PAHs for reaction

The 26 January 2001 M 7.6 Bhuj, India, Earthquake: Observed and Predicted Ground Motions

Although local and regional instrumental recordings of the devastating 26, January 2001, Bhuj earthquake are sparse, the distribution of macroseismic effects can provide important constraints on the mainshock ground motions. We compiled available news accounts describing damage and other effects and interpreted them to obtain modified Mercalli intensities (MMIs) at >200 locations throughout the Indian subcontinent. These values are then used to map the intensity distribution throughout the subcontinent using a simple mathematical interpolation method. Although preliminary, the maps reveal several interesting features. Within the Kachchh region, the most heavily damaged villages are concentrated toward the western edge of the inferred fault, consistent with western directivity. Significant sediment-induced amplification is also suggested at a number of locations around the Gulf of Kachchh to the south of the epicenter. Away from the Kachchh region, intensities were clearly amplified significantly in areas that are along rivers, within deltas, or on coastal alluvium, such as mudflats and salt pans. In addition, we use fault-rupture parameters inferred from teleseismic data to predict shaking intensity at distances of 0–1000 km. We then convert the predicted hard-rock ground-motion parameters to MMI by using a relationship (derived from Internet-based intensity surveys) that assigns MMI based on the average effects in a region. The predicted MMIs are typically lower by 1–3 units than those estimated from news accounts, although they do predict near-field ground motions of approximately 80%g and potentially damaging ground motions on hard-rock sites to distances of approximately 300 km. For the most part, this discrepancy is consistent with the expected effect of sediment response, but it could also reflect other factors, such as unusually high building vulnerability in the Bhuj region and a tendency for media accounts to focus on the most dramatic damage, rather than the average effects. The discrepancy may also be partly attributable to the inadequacy of the empirical relationship between MMI and peak ground acceleration (PGA), when applied to India. The MMI–PGA relationship was developed using data from California earthquakes, which might have a systematically different stress drop and therefore, a different frequency content than intraplate events. When a relationship between response spectra and MMI is used, we obtain larger predicted MMI values, in better agreement with the observations

Information system's project management and the phenomenon of trust.

The aim of this research was to investigate how the continual low success rate of IS projects could be improved through an evaluation of success and failure factors. A literature review revealed a comprehensive but uncoordinated history of research into the identification of the critical factors. This proved to be inconclusive, but did indicate that project management contributed more to the failures than the technology. A model for expressing the complexity of IS project environments is proposed to aid project teams with their strategy. Also, the criteria for measuring success of both project managemenat nd IS projects has been extended. Although many disciplines had considered trust as a success factor, this was missing within the domain of project management. To examine the effect of trust in an IS project environment a game termed Project Paradox was designed and run. A lack of trust was found to be compounded by conflicting objectives inherent within IS projects. It is recommended that the issues relating to trust should be considered and managed as an integral part of a risk analysis. To enable this to be realised in practice a framework for a Trust Audit is proposed. The thesis concludes with a number of research initiatives aimed at improving the success rate of IS projects

Elite formation, power and space in contemporary London

In this paper we examine elite formation in relation to money power within the city of London. Our primary aim is to consider the impact of the massive concentration of such power upon the city’s political life, municipal and shared resources and social equity. We argue that objectives of city success have come to be identified and aligned with the presence of wealth elites while wider goals, of access to essential resources for citizens, have withered. A diverse national and global wealth-elite is drawn to a city with an almost unique cultural infrastructure, fiscal regime and ushering butler class of politicians. We consider how London is being made for money and the monied – in physical, political and cultural terms. We conclude that the conceptualisation of elites as wealth and social power formations operating within urban spatial arenas is important for capturing the nature of new social divisions and changes

Power spectrum of many impurities in a d-wave superconductor

Recently the structure of the measured local density of states power spectrum of a small area of the \BSCCO (BSCCO) surface has been interpreted in terms of peaks at an "octet" of scattering wave vectors determined assuming weak, noninterfering scattering centers. Using analytical arguments and numerical solutions of the Bogoliubov-de Gennes equations, we discuss how the interference between many impurities in a d-wave superconductor alters this scenario. We propose that the peaks observed in the power spectrum are not the features identified in the simpler analyses, but rather "background" structures which disperse along with the octet vectors. We further consider how our results constrain the form of the actual disorder potential found in this material.Comment: 5 pages.2 figure

Welcome to Pikettyville? Mapping London's Alpha Territories

This paper considers the influence of the burgeoning global ‘super-rich’ on contemporary socio-spatialization processes in London in the light of a contemporary re-reading of Pahl’s classic volume, Whose City? It explores if a turn to ‘big data’ – in the form of commercial geodemographic classifications – can offer any additional insights to a sociological approach to the study of the ‘super-rich’ that extends the ‘spatialization of class’ thesis further ‘up’ the class structure