3,151 research outputs found
Aerodynamic and performance characteristics of a passive leading edge Kruger flap at low Reynolds numbers
No full textAn experimental and numerical study was performed on a Clark Y aerofoil with a
10% chord leading edge Kruger flap to examine its aerodynamic performance at
Reynolds numbers of 0.6 × 106, 1 × 106, and 1.6 × 106, to help to identify the
forces and moments acting on a basic configuration. A detailed comparison of the
numerical and experimental data is presented in this paper. The leading edge
flap was effective at high angles of attack with an increase in CL of up to 18%
over a conventional no flap configuration and delayed separation by up to 3°.
The moments around the Kruger flap rotation point were calculated from the
numerical analysis as an initial stage in the design of a UAV passive flap
system and they are also presented in the p
Experimental and numerical investigation of leading edge Krueger flaps at low Reynolds numbers
No full textRecent publications examining the flight of Eagles have shown that leading edge feather deflections occur on the lower surface of the wings in free flight to create a leading edge flap analogous to a Krueger flap system.
Such passive high lift devices may be adaptable to the lifting surfaces of unmanned air vehicles (UAVs). This work is aimed to an application of a passive leading edge Krueger device which will deploy during the landing and takeoff stages of a UAV flight. Cont/d
External interventions and the duration of civil wars
No full textThe authors combine an empirical model of external intervention, with a theoretical model of civil war duration. Their empirical model of intervention allows them to analyze civil war duration, using"expected"rather than"actual"external intervention as an explanatory variable in the duration model. Unlike previous studies, they find that external intervention is positively associated with the duration of civil war. They distinguish partial third-party interventions that extend the length of war, from multilateral"peace"operations, which have a mandate to restore peace without taking sides - and which typically take place at war's end, or at least when both sides have agreed to a cease-fire. In a future paper, the authors will examine whether partial third-party interventions - whatever their effect on a war's duration - increase the risk of war's recurrence. If that proves true, then even if interventions reduce the length of civil war, they may do so at the cost of further destabilizing the political system, and sowing the seeds of future rebellion.Children and Youth,Peace&Peacekeeping,Post Conflict Reconstruction,Post Conflict Reconstruction,International Affairs,Post Conflict Reconstruction,Social Conflict and Violence,Peace&Peacekeeping,Post Conflict Reconstruction,International Affairs
Dataset for Deep learning enabled design of complex transmission matrices for universal optical components
No full textData comprising Numerical simulation results and deep learning results to supprot article N. J. Dinsdale, P. R. Wiecha, M. Delaney, J. Reynolds, M. Ebert, I. Zeimpekis, D. J. Thomson, G. T. Reed, P. Lalanne, K. Vynck, O. L. Muskens "Deep learning enabled design of complex transmission matrices for universal optical components". ACS Photonics (2020). Each figure has a Readme file attached.</span
Talmudic Quotations in Nicholas of Lyra's Postilla Literalis
No full textThe Postilla literalis super totam Bibliam, written by Nicholas of Lyra (France, 1270- 1349) is remarkable for the extensive use of texts and oral traditions of Jewish origin made by its author. This paper deals with the place of the Talmud among the Jewish sources cited in the Postilla. For Nicholas the Talmud was a new doctrine invented by the Jews sometime in their past but believed to be divine and to be given to Moses in Sinai. When reading Nicholas' Postilla, one finds many citations from medieval Jewish sources, but very few excerpts from the Talmud except as polemic with the purpose of ridiculing and disproving them. It appears that Nicholas avoided direct Talmudic citations within the Postilla, likely due to the hostile attitudes prevalent specifically toward the Talmud within the Christian world he inhabited
Post Penicillin Antibiotics: From acceptance to resistance?
No full textEdited transcript of a Witness Seminar held at the Wellcome Institute for the History of Medicine, in London, on 12 May 1998. First published by the Wellcome Trust, 2000. ©The Trustee of the Wellcome Trust, London, 2000. All volumes are freely available at www.history.qmul.ac.uk/research/modbiomed/wellcome_witnesses/Annotated and edited transcript of a Witness Seminar held on 12 May 1998. Introduction by E M Tansey.Annotated and edited transcript of a Witness Seminar held on 12 May 1998. Introduction by E M Tansey.Annotated and edited transcript of a Witness Seminar held on 12 May 1998. Introduction by E M Tansey.Annotated and edited transcript of a Witness Seminar held on 12 May 1998. Introduction by E M Tansey.The introduction of penicillin during the Second World War led to a revolution in both drug development and therapeutics. Several important themes emerged during the course of the meeting – the discovery of the antimicrobial effects of actinomycetes, streptomycin as specific therapy for TB, scientific research in pharmaceutical company laboratories and the mechanisms whereby the products of that research were manufactured, marketed and utilized in the clinic, the increasing recognition of the clinical successes and the subsequent problems of antibiotic resistance, and the discovery of the mechanisms that transferred resistance. Participants include: Dr Ralph Batchelor, Sir John Crofton, Professor Naomi Datta, Dr Peter Doyle, Professor Harold Lambert, Professor D A Mitchison and Professor Gordon Stewart. Tansey E M, Reynolds L A. (eds) (2000) Post penicillin antibiotics: From acceptance to resistance? Wellcome Witnesses to Twentieth Century Medicine, vol. 6. London: The Wellcome Trust.The Wellcome Trust is a registered charity, no. 210183
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’
Dissociation of erythema and p53 protein expression in human skin following UVB irradiation, and induction of p53 protein and mRNA following application of skin irritants
No full textThe mechanisms mediating the varied effects of ultraviolet radiation (UVR) on human skin are unclear, although a relationship between erythema and DNA damage is suggested by photosensitivity in xeroderma pigmentosum. Increased p53 expression in response to UVR is thought to reflect direct DNA damage, but recent evidence indicates that UVR also activates membrane and cytosolic signal transduction pathways. In this study, we have investigated the relationship between erythema and p53 induction following UVB and whether this p53 response is specific to UVR. p53 protein expression was determined by immunocytochemistry using the monoclonal antibody DO7, and p53 mRNA expression was examined by non-isotopic in situ hybridization. Incremental doses of UVB were administered to the lower back of eight subjects. Immunostaining revealed that p53 positive nuclei were significantly increased 8 h after suberythemogenic doses of UVB (79 +/- 12), compared to normal unirradiated skin (8 +/- 6, p < 0.0005), but no change in p53 mRNA was seen. Higher UVB doses, which resulted in moderate erythema, resulted in a similar or greater induction of p53 protein. Indomethacin (1% w/v), applied immediately after UVB irradiation, significantly inhibited UVB erythema at 8 h in six subjects (p < 0.005), but did not reduce p53 immunostaining. Dithranol (1 microgram/microliter, n = 8), sodium dodecylsulphate (5%, n = 4), and retinoic acid (0.5%, n = 4), applied for 48 h, caused erythema, significantly increased p53 protein levels (p < 0.05), and also increased p53 mRNA. Our results show that in human skin, UVB-induced p53 elevation can be dissociated from erythema and skin irritants can also induce p53 protein. The induction of p53 mRNA by irritants but not UVR suggests different mechanisms of action
Author(s): Ezra Brown and Nicholas Loehr Source
No full textJSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. . Why is PSL(2, 7) = GL(3, 2)? Mathematical Association of America Ezra Brown and Nicholas Loehr 1. INTRODUCTION. The groups of invertible matrices over finite fields are among the first groups we meet in a beginning course in modern algebra. Eventually, we find out about simple groups and that the unique simple group of order 168 has two representations as a group of matrices. And this is where we learn that the group of 2x2 unimodular matrices over a seven-element field, with / and -/ identified, is isomorphic to the group of invertible 3x3 matrices over a 2-element field. In short, it is a fact that PSL(2, 7) = GL(3, 2). Many of us are surprised by this fact: why should a group of 2 x 2 matrices with mod-7 integer entries be isomorphic to a group of 3 x 3 binary matrices? There are a number of proofs of this remarkable theorem. Dickson [1, p. 303] gives a proof based on his general theorem giving uniform sets of generators and relations for the family of groups SL(2, q), where q is any prime power. One checks that the relations appearing in Dickson's presentation of PSL(2, 7) are satisfied by certain generators of GL(3, 2), implying that these groups have the same presentations and are therefore isomorphic. Dummit and Foote [2, show that every simple group of order 168 is necessarily isomorphic to the automorphism group Aut(.F) of the Fano plane T. They then show that Aut(^) = GL(3, 2) and that PSL(2, 7) is a simple group of order 168; the isomorphism theorem follows. Rotman gives the result as an exercise [5, Exercise 9.26, p. 281]. A hint is to begin with a simple group G of order 168 and use the seven conjugates of a Sylow 2-subgroup P of G to construct a sevenpoint projective plane; the proof is similar to Dummit and Foote's proof. Jeurissen [4] proves the result by showing that both PSL(2, 7) and GL(3, 2) are subgroups of index 2 of the automorphism group of a Coxeter graph. Elkies The aim of this paper is to give a proof that PSL(2, 7) = GL(3, 2) that is elementary in the sense that it uses neither simplicity, nor projective geometry, nor block designs. We will not prove the fact that any two simple groups of order 168 are isomorphic, nor will we use this fact in our proof. What makes our proof work is that: (a) we can identify GL(3, 2) with the set of invertible F2-linear transformations on the finite field with eight elements; (b) 7 = 23 -1; (c) the nonzero squares mod 7 are precisely the powers of 2 mod 7; (d) squaring mod 2 is additive (the Freshman's Dream); and (e) the mapping k h+ -i/k mod 7 translates to a bit-switch mod 2 -which is linear. We begin by giving functional descriptions for both groups, determining their sizes
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Nicholas and Anna Ricco Ethics Awards
No full textThis paper was awarded a Nicholas and Anna Ricco Ethics Award for 2013. In this paper, the author discusses the "Triple-P" domains of ethical behavior: (1) the understanding of privacy ethics, (2) regards to piracy and plagiarism, and (3) pilfering and profiteering
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