2,525 research outputs found
Compressible Flows at Small Reynolds Numbers
No full textThe problem of the slow viscous flow of a gas past a sphere is considered. The fluid cannot be treated incompressible in the limit when the Reynolds number Re, and the Mach number M, tend to zero in such a way that Re ~ o(M^2 ). In this case, the lowest order approximation to the steady Navier-Stokes equations of motion leads to a paradox discovered by Lagerstrom and Chester. This paradox is resolved within the framework of continuum mechanics using the classical slip condition and an iteration scheme that takes into account certain terms in the full Navier-Stokes equations that drop out in the approximation used by the above authors. It is found however that the drag predicted by the theory does not agree with R. A. Millikan's classic experiments on sphere drag.
The whole question of the applicability of the Navier-Stokes theory when the Knudsen number M/Re is not small is examined. A new slip condition is proposed. The idea that the Navier-Stokes equations coupled with this condition may adequately describe small Reynolds number flows when the Knudsen number is not too large is looked at in some detail. First, a general discussion of asymptotic solutions of the equations for all such flows is given. The theory is then applied to several concrete problems of fluid motion. The deductions from this theory appear to interpret and summarize the results of Millikan over a much wider range of Knudsen numbers (almost up to the free molecular or kinetic limit) than hitherto Believed possible by a purely continuum theory. Further experimental tests are suggested and certain interesting applications to the theory of dilute suspensions in gases are noted. Some of the questions raised in the main body of the work are explored further in the appendices. </p
C.S. Lewis: Reactions from Women
No full textRecounts the experiences of eight women (including the author) who knew C.S. Lewis
C.S. Lewis’s theory of Sehnsucht as a tool for theorizing L.M. Montgomery’s experience of ‘The Flash'
No full textHigh-k fluoropolymers dielectrics for low-bias ambipolar organic light emitting transistors (Olets)
No full textFunding Information: Author Contributions: Conceptualization, A.A. and C.S.; methodology, A.A. and C.S.; validation, A.A., K.G.-R., and C.S.; data curation, A.A., K.G.-R., and C.S.; writing—original draft preparation, A.A. and C.S.; writing—review and editing, A.A., K.G.-R., and C.S.; supervision, C.S.; project administration, C.S.; funding acquisition, C.S. All authors have read and agreed to the published ver-sion ofFunding:the manuThescript.authors acknowledge the support from the Academy of Finland Flagship Program (Grant No.: 320167, PREIN) and the Aalto seed funding scheme. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Organic light emitting transistors (OLETs) combine, in the same device, the function of an electrical switch with the capability of generating light under appropriate bias conditions. In this work, we demonstrate how engineering the dielectric layer based on high-k polyvinylidene fluoride (PVDF)-based polymers can lead to a drastic reduction of device driving voltages and the improvement of its optoelectronic properties. We first investigated the morphology and the dielectric response of these polymer dielectrics in terms of polymer (P(VDF-TrFE) and P(VDF-TrFE-CFE)) and solvent content (cyclopentanone, methylethylketone). Implementing these high-k PVDF-based dielectrics enabled low-bias ambipolar organic light emitting transistors, with reduced threshold voltages (<20 V) and enhanced light output (compared to conventional polymer reference), along with an overall improvement of the device efficiency. Further, we preliminary transferred these fluorinated high-k dielectric films onto a plastic substrate to enable flexible light emitting transistors. These findings hold potential for broader exploitation of the OLET platform, where the device can now be driven by commercially available electronics, thus enabling flexible low-bias organic electronic devices.Peer reviewe
Intermediate disturbance hypothesis in phytoplankton ecology: proceedings of the 8th Workshop of the International Association of Phytoplankton Taxonomy and Ecology held in Baja (Hungary), 5-15 July 1991
No full textedited by J. Padisa?k, C.S. Reynolds & U. Sommer.x, 199 p. : ill. ; 27 cm
C.S. Lewis: adaptations of life and work
No full textThe author discusses film representations of the life of C.S. Lewis – a famous English Christian writer. She also focuses on adaptations (that include books, television and cinema) of his most famous series The Chronicles of Narnia – series that for already sixty years have been published all over the world
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’
The Nurse of Elfland: Lizzie Endicott and C.S. Lewis
No full textIn Surprised by Joy, C.S. Lewis introduced Lizzie Endicott as the first of two other blessings in his childhood, even before his introduction of Warnie. But apart from his abbreviated 136-word biography, very little is known about the nurse who introduced Lewis to faery tales. Based on the Lewis Family Papers, genealogical research, and personal interviews with Lizzie’s relatives, this article introduces Lizzie to the world of Lewismania. It also suggests various ways in which Lizzie influenced the man and the author that C.S. Lewis became, as well as the mythical worlds he created and Lewis’s anonymous tributes to her
Remembering C.S. Lewis recollections of those who knew him
No full textIn this intimate, candid, and sometimes surprising community biography of the celebrated author and Christian apologist, twenty-four men and women who knew C.S. Lewis, as teacher, colleague, friend, offer their reminiscences and impressions of the complex man behind the critical and academic acclaim
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