27 research outputs found
On the importance of parallel magnetic-field fluctuations for electromagnetic instabilities in STEP
No full textThis paper discusses the importance of parallel perturbations of the magnetic-field in gyrokinetic simulations of electromagnetic instabilities and turbulence at mid-radius in the burning plasma phase of the conceptual high-β, reactor-scale, tight-aspect-ratio tokamak STEP. Previous studies have revealed the presence of unstable hybrid kinetic ballooning modes (hKBMs) and subdominant microtearing modes at binormal scales approaching the ion Larmor radius. In this STEP plasma it was found that the hKBM requires the inclusion of parallel magnetic-field perturbations to be linearly unstable. Here, the extent to which the inclusion of fluctuations in the parallel magnetic-field can be relaxed is explored through gyrokinetic simulations. In particular, the frequently used MHD approximation (dropping δB∥ and setting the ∇B drift frequency equal to the curvature drift frequency) is discussed and simulations explore whether this approximation is useful for modelling STEP plasmas. It is shown that the MHD approximation can reproduce some of the linear properties of the full STEP gyrokinetic system, but is too stable at low ky and nonlinear simulations using the MHD approximation result in very different transport states. It is demonstrated that the MHD approximation is challenged by the high β′ values in STEP, and that the approximation improves considerably at lower β′ . Furthermore, it is shown that the sensitivity of STEP to δB∥ fluctuations is primarily because the plasma sits close to marginality and it is shown that in slightly more strongly driven conditions the hKBM is unstable without δB∥. Crucially, it is demonstrated that the state of large transport typically predicted by local electromagnetic gyrokinetic simulations of STEP plasmas is not solely due to δB∥ physics
Samoyedic Diary : Early Years of Visual Anthropology in the Soviet Arctic
No full textACKNOWLEDGMENTS The author appreciates the comments and remarks of Craig Campbell (University of Texas, Austin) and of all the participants in the workshop dedicated to the commemoration of Vladimir G. Bogoras, held on May 14, 2015, in the framework of the joint anthropological seminar of the Department of Ethnography of Siberia at the Museum of Anthropology and Ethnography of the Russian Academy of Sciences and the European University at Saint Petersburg. The author also thanks Joselyne Dudding (Museum of Archaeology and Anthropology, University of Cambridge) and David G. Anderson (University of Aberdeen) for a discussion of Ethel John Lindgren's cinematic and photographic materials, which helped in the understanding and contextualization of the Prokofievs’ chronicles. The author is also grateful to Nikolai B. Vakhtin (European University at Saint Petersburg) for his comments on the first version of the article. I am very thankful to Olga Pak for her translation of this article. A Russian version will be published in Antropologicheskii Forum (2016, no. 29). FUNDING This article was written with support from the projects ‘‘Etnos:A life history of theetnosconcept among the Peoplesof the North’’ (European Social Research Council ES=K006428=1) and ‘‘EtnosandMinzu: Histories and Politics ofIdentity Governance in Eurasia’’ (The Leverhulme Trust, IN-2012-138). In addition the Russian Science Foundation(RNF 14-18-02785) supported the archival work in Saint Petersburg during the last stage of the research.Peer reviewe
Exploring small area demand for grocery retailers in tourist areas
No full textNewing, A., Clarke, G.P. and Clarke, M. 2014. Exploring small area demand for grocery retailers in tourist areas. Tourism Economics, 20(2), pp.407-427This paper uses data from a major loyalty card scheme to draw insights about the characteristics of grocery expenditure by tourists. The authors explore the volume, value and composition of store based visitor expenditure using consumer data from the loyalty card scheme. They focus on grocery spending at selected stores in Cornwall, a popular tourist destination in South West England. Theloyalty card data provide a valuable source rarely available for academic investigations. The authors are able to analyse visitor spend by socio-economic and geodemographic characteristics, drawing a range of comparisons with residential demand from within the store catchment areas. They demonstrate that visitor grocery expenditure is complex and varies by store, destination and type of customer. The paper presents evidence to suggest that the current approaches used to estimate sales uplift and local-level economic impact from visitor demand are unable to account for the complexities of this form of expenditure. Based on these insights, the authors recommend that sophisticated modelling is employed to estimate the impact of visitor expenditure
Investigation of a new chiral auxiliary derived chemoenzymatically from toluene: Experimental and computational study
No full textA tricyclic chiral auxiliary, prepared from the enzymatically derived cis-arene dihydrodiol metabolite of toluene, was investigated as a means of asymmetric induction in several different reactions. The auxiliary was converted to an oxaziridine and its utility in hydroxylation, providing low levels of enantiomeric excess, was compared with that of Davisâ s oxaziridine. Insight into the origin of stereoinduction in this reaction is provided and is based on computational Monte Carlo Multiple Minimum (MCMM) searches using the OPLS3 forcefield. The use of the auxiliary group in the alkylation of appended esters proved disappointing. Diels-Alder cycloaddition of an acrylate, derived from the auxiliary group, with cyclohexadiene furnished a mixture of diastereomeric adducts in essentially equal amounts. The adducts were separated and the corresponding enantiomeric residues were isolated with good enantiomeric excess. Evidence of reasonable levels of asymmetric induction in the above processes was lacking. Experimental and spectral data are provided for all key compounds.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
pyrokinetics
No full text<h2>What's Changed</h2>
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<li>Bugfix/docker publishing issues by @LiamPattinson in https://github.com/pyro-kinetics/pyrokinetics/pull/293</li>
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<p><strong>Full Changelog</strong>: https://github.com/pyro-kinetics/pyrokinetics/compare/v0.6.0...v0.6.1</p>If you use this software, please cite it as below
pyrokinetics
No full textPython library to run and analyse gyrokinetics simulationsIf you use this software, please cite it as below
Author Correction: Amine hemilability enables boron to mechanistically resemble either hydride or proton
No full text"PROTON SPONGES": A RIGID ORGANIC SCAFFOLD TO REVEAL THE QUANTUM STRUCTURE OF THE INTRAMOLECULAR PROTON BOND
No full textAuthor Institution: Yale University, P. O. Box 208107, New Haven, CT, 06520; Johns Hopkins University, 3400 North Charles Street, Baltimore, MD, 21218; Brock University, St. Catherines, ON, Canada L2S 3A1Spectroscopic analysis of systems containing charged hydrogen bonds (e.g. the Zundel ion, ) in a vibrationally cold regime is useful in decongesting numerous anharmonic features common to room temperature measurements.[Roscioli, J. R.; et. al. Science 2007] This approach has been extended to conjugate acids of the "Proton Sponge" family of organic compounds, which contain strong intramolecular hydrogen bonds between proton donor (D) and acceptor (A) groups at the 1- and 8-positions. By performing vibrational predissociation spectroscopy on cryogenically cooled ions, we explore how the proximity and spatial orientation of D and A moieties relates to the spectroscopic signature of the shared proton. In the cases studied (), we observe strong anharmonic couplings between the shared proton and dark states that persist at these cryogenic temperatures. This leads to intense NH stretching features throughout the nominal CH stretching region (). Isotopic substitution has verified that the oscillator strength of these broad features is driven by NH stretching. Furthermore, the study of A = O(C=O)Ph has provided a spectroscopic snapshot of the shared proton at work as an active catalytic moiety fostering ester hydrolysis by first order acylium fission (). This is apparent by the high frequency carbonyl stretch at , which is a consequence of the strong hydrogen bond to the ether-ester oxygen atom. Thus, these "Proton Sponges" are useful model systems that unearth the quantum structure and reactivity of shared proton interactions in organic compounds
Cervical cytology and the diagnosis of cervical cancer in older women
No full textThis is the final version of the article. Available from the publisher via the DOI in this record.OBJECTIVES: Most non-screen-detected cervical cancers are advanced stage. We assess the potential for cytology to expedite diagnosis when used outside of routine call and recall screening for cervical cancer. METHODS: Two cohorts of women with cytology that did not appear to have been taken as part of routine screening, nested within a census of cervical cytology, in England between April 2007 and March 2010 were studied: 93,322 women aged 40-69 at first cytology, and 14,668 women aged ≥70. The diagnostic performance of high grade cervical squamous intraepithelial lesion (HSIL) or worse cytology was estimated. We also estimated case-fatality from stage distribution in women aged ≥66 with and without cytology in the year prior to diagnosis. RESULTS: There were 259 cancers diagnosed in women aged 40-69 at first cytology, and 78 in women aged ≥70. The sensitivity of cytology ≥ HSIL for cancer was 89% and 83% respectively, and the number of women needed to test to identify one cancer was 404 (95% confidence interval [CI]: 355-462) and 226 (95% CI: 177-292) respectively. Women aged ≥66 with cytology within a year of diagnosis had earlier stage cancers than those without, corresponding to a 17-22% reduction in case fatality. CONCLUSIONS: Cervical cytology is an excellent identifier of cancer among women tested outside routine screening call and recall. Its use as a triage tool, for instance in women with vague gynaecological symptoms, could facilitate earlier stage diagnosis and reduce cervical cancer mortality.This work was supported by Cancer Research UK [C8162/10406
and C8162/12537]. The corresponding author had full access to
all the data in the study and had final responsibility for the
decision to submit for publication. The funder had no input in
the analysis or interpretation of the data or the writing of the
paper
Marketing for Small Business: The Development of a Practical and Conceptual Contribution towards a new Paradigm 1986 to 2011
No full textThis thesis is about the role, nature and importance of marketing within small firms. The definition for small firms’ used here is organisations’ with up to 50 employees. This is the definition used by The Department for Business, Innovation and Skills (2012). There are over four million of such commercial organisations in the UK and they account for over half of the UK’s GDP and over half of the UK’s employment (The Department for Business Innovation and Skills November 2011 /12). Most firms’ in the UK are small and yet the marketing for small firms’ seems to be a neglected area in the standard text books and in the mainstream business school curriculum. Why is this and what can be done to make the subject of marketing more relevant and more appropriate to the smaller enterprise? This doctorial submission is based on published work. There are 24 individual pieces of work making up the submission. All of the works submitted are related to the subject of marketing for small business. Throughout the works’ submitted the author addresses a fundamental question which has occupied his mind for many years. This question is highly pertinent to the developing subject of marketing within small firms’ (Gilmore and Coviello, 1999). The question is ‘is conventional marketing theory and practice from the ‘classical school’ applicable to all types of organisations no matter what their size’? The fundamental question this work addresses is do smaller firms need a different sort of marketing, more suited to their particular needs (Nyman, Berck, and Worsdorfer, 2006; Reynolds and Day, 2011; Hills and Hultman, 2011; Shaw, 2002; Gilmore, 2011; McAuley, 2011; Hills and LaForge, 1992)? The author can find no real evidence of any need for a totally new paradigm although some areas of the standard business school ‘model’ of marketing management might need some important adaptation to make it more suitable for the majority of smaller firms’. The key approach would seem to be standardisation as far as possible then necessary adaptation. The collection of papers and related materials making up this thesis submission conclude that in many cases the central core hub of marketing that has become known as the ‘classicist philosophy of strategic marketing management’ is appropriate in many areas (Drucker, 1954). It can often be employed to the smaller enterprise with beneficial commercial effects (see Reynolds, 2007; Brennan, Baines, and Garneau, 2003). The author has attempted to demonstrate that a body of work has developed and evolved over time in a purposeful manner and with a common theme. The material submitted here, placed into three separate but related categories, has been structured to have an overall thematic shape. The ‘grand theme’ interwoven into this account is marketing for small business. The author does not claim to have investigated every vestige of the subject but does feel that over the years he has made a contribution to the knowledge in this area. Each of the three sub - themes used in this work are related and can be integrated into a ‘grand narrative’ or ‘story line’. This ‘grand narrative’ is encapsulated in the title of this thesis which is; ‘Marketing for small business: The development of a practical and conceptual contribution towards a new paradigm 1986 to 2011’
