21 resultados para OMEGA LIMITS

em Aston University Research Archive


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Purpose - The idea that knowledge needs to be codified is central to many claims that knowledge can be managed. However, there appear to be no empirical studies in the knowledge management context that examine the process of knowledge codification. This paper therefore seeks to explore codification as a knowledge management process. Design/methodology/approach - The paper draws on findings from research conducted around a knowledge management project in a section of the UK Post Office, using a methodology of participant-observation. Data were collected through observations of project meetings, correspondence between project participants, and individual interviews. Findings - The principal findings about the nature of knowledge codification are first, that the process of knowledge codification also involves the process of defining the codes needed to codify knowledge, and second, that people who participate in the construction of these codes are able to interpret and use the codes more similarly. From this it can be seen that the ability of people to decodify codes similarly places restrictions on the transferability of knowledge between them. Research limitations/implications - The paper therefore argues that a new conceptual approach is needed for the role of knowledge codification in knowledge management that emphasizes the importance of knowledge decodification. Such an approach would start with one's ability to decodify rather than codify knowledge as a prerequisite for knowledge management. Originality/value - The paper provides a conceptual basis for explaining limitations to the management and transferability of knowledge. © Emerald Group Publishing Limited.

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Purpose: To determine the validity of covering a corneal contact transducer probe with cling film as protection against the transmission of Creutzfeldt-Jakob disease (CJD). Methods: The anterior chamber depth, lens thickness and vitreous chamber depth of the right eyes of 10 subjects was recorded, under cycloplegia, with and without cling film covering over the transducer probe of a Storz Omega Compu-scan Biometric Ruler. Measurements were repeated on two occasions. Results: Cling film covering did not influence bias or repeatability. Although the 95% limits of agreement between measurements made with and without cling film covering tended to exceed the intrasessional repeatability, they did not exceed the intersessional repeatability of measurements taken without cling film. Conclusions: The results support the use of cling film as a disposable covering for corneal contact A-scan ultrasonography to avoid the risk of spreading CJD from one subject to another. © 2003 The College of Optometrists.

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Recent studies have stressed the importance of ‘open innovation’ as a means of enhancing innovation performance. The essence of the open innovation model is to take advantage of external as well as internal knowledge sources in developing and commercialising innovation, so avoiding an excessively narrow internal focus in a key area of corporate activity. Although the external aspect of open innovation is often stressed, another key aspect involves maximising the flow of ideas and knowledge from different sources within the firm, for example through knowledge sharing via the use of cross-functional teams. A fully open innovation approach would therefore combine both aspects i.e. cross-functional teams with boundary-spanning knowledge linkages. This suggests that there should be complementarities between the use cross-functional teams with boundary-spanning knowledge linkages i.e. the returns to implementing open innovation in one innovation activity is should be greater if open innovation is already in place in another innovation activity. However, our findings – based on a large sample of UK and German manufacturing plants – do not support this view. Our results suggest that in practice the benefits envisaged in the open innovation model are not generally achievable by the majority of plants, and that instead the adoption of open innovation across the whole innovation process is likely to reduce innovation outputs. Our results provide some guidance on the type of activities where the adoption of a market-based governance structure such as open innovation may be most valuable. This is likely to be in innovation activities where search is deterministic, activities are separable, and where the required level of knowledge sharing is correspondingly moderate – in other words those activities which are more routinized. For this type of activity market-based governance mechanisms (i.e. open innovation) may well be more efficient than hierarchical governance structures. For other innovation activities where outcomes are more uncertain and unpredictable and the risks of knowledge exchange hazards are greater, quasi-market based governance structures such as open innovation are likely to be subject to rapidly diminishing returns in terms of innovation outputs.

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In this article we compare the current debate about global warming with the earlier discourse of Limits to Growth (LtG) of the 1970's. We are especially interested in the similarities of and differences between the two cases and therefore compare the policy challenges and lessons to be drawn. While the two debates differ on important issues, they share a technocratic orientation to public policy, and susceptibility to similar pitfalls. In both debates alarming scenarios about future catastrophes play an important role. We suggest that climate change policy discourse needs to focus more closely on the social, economic, and political dimensions of climate change, as opposed to its excessive emphasis on emission reduction targets. We also argue that an excessive faith in the market mechanisms to supply global warming mitigation technologies is problematic. In this respect, we provide a reality check regarding the political implications of emission targets and timetables and suggest how policy issues can be moved forward.

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The thesis is concerned with the electron properties of single-polepiece magnetic electron lenses especially under conditions of extreme polepiece saturation. The electron optical properties are first analysed under conditions of high polepiece permeability. From this analysis, a general idea can be obtained of the important parameters that affect ultimate lens performance. In addition, useful information is obtained concerning the design of improved lenses operating under conditions of extreme polepiece saturation, for example at flux densities of the order of 10 Tesla. It is shown that in a single-polepiece lens , the position and shape of the lens exciting coil plays an important role. In particular, the maximum permissible current density in the windings,rather than the properties of the iron, can set a limit to lens performance. This factor was therefore investigated in some detail. The axial field distribution of a single-polepiece lens, unlike that of a conventional lens, is highly asymmetrical. There are therefore two possible physical arrangements of the lens with respect to the incoming electron beam. In general these two orientations will result in different aberration coefficients. This feature has also been investigated in some detail. Single-pole piece lenses are thus considerably more complicated electron- optically than conventional double polepiece lenses. In particular, the absence of the usual second polepiece causes most of the axial magnetic flux density distribution to lie outside the body of the lens. This can have many advantages in electron microscopy but it creates problems in calculating the magnetic field distribution. In particular, presently available computer programs are liable to be considerably in error when applied to such structures. It was therefore necessary to find independent ways of checking the field calculations. Furthermore, if the polepiece is allowed to saturate, much more calculation is involved since the field distribution becomes a non-linear function of the lens excitation. In searching for optimum lens designs, care was therefore taken to ensure that the coil was placed in the optimum position. If this condition is satisfied there seems to be no theoretical limit to the maximum flux density that can be attained at the polepiece tip. However , under iron saturation condition, some broadening of the axial field distribution will take place, thereby changing the lens aberrations . Extensive calculations were therefore made to find the minimum spherical and chromatic aberration coefficients . The focal properties of such lens designs are presented and compared with the best conventional double-polepiece lenses presently available.

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The thesis examines and explains the development of occupational exposure limits (OELs) as a means of preventing work related disease and ill health. The research focuses on the USA and UK and sets the work within a certain historical and social context. A subsidiary aim of the thesis is to identify any short comings in OELs and the methods by which they are set and suggest alternatives. The research framework uses Thomas Kuhn's idea of science progressing by means of paradigms which he describes at one point, `lq ... universally recognised scientific achievements that for a time provide model problems and solutions to a community of practitioners. KUHN (1970). Once learned individuals in the community, `lq ... are committed to the same rules and standards for scientific practice. Ibid. Kuhn's ideas are adapted by combining them with a view of industrial hygiene as an applied science-based profession having many of the qualities of non-scientific professions. The great advantage of this approach to OELs is that it keeps the analysis grounded in the behaviour and priorities of the groups which have forged, propounded, used, benefited from, and defended, them. The development and use of OELs on a larger scale is shown to be connected to the growth of a new profession in the USA; industrial hygiene, with the assistance of another new profession; industrial toxicology. The origins of these professions, particularly industrial hygiene, are traced. By examining the growth of the professions and the writings of key individuals it is possible to show how technical, economic and social factors became embedded in the OEL paradigm which industrial hygienists and toxicologists forged. The origin, mission and needs of these professions and their clients made such influences almost inevitable. The use of the OEL paradigm in practice is examined by an analysis of the process of the American Conference of Governmental Industrial Hygienists, Threshold Limit Value (ACGIH, TLV) Committee via the Minutes from 1962-1984. A similar approach is taken with the development of OELs in the UK. Although the form and definition of TLVs has encouraged the belief that they are health-based OELs the conclusion is that they, and most other OELs, are, and always have been, reasonably practicable limits: the degree of risk posed by a substance is weighed against the feasibility and cost of controlling exposure to that substance. The confusion over the status of TLVs and other OELs is seen to be a confusion at the heart of the OEL paradigm and the historical perspective explains why this should be. The paradigm has prevented the creation of truly health-based and, conversely, truly reasonably practicable OELs. In the final part of the thesis the analysis of the development of OELs is set in a contemporary context and a proposal for a two-stage, two-committee procedure for producing sets of OELs is put forward. This approach is set within an alternative OEL paradigm. The advantages, benefits and likely obstacles to these proposals are discussed.

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This thesis is about the relationship between schooling and the economic and political structures which constrain its institutional framework. It focusses on teachers, as mediators of structural constraints, and on middle schools, as institutions which occupy a functionally transitional place between the primary and secondary traditions. In approaching the problem of linking the different perspectives of macro and micro sociologies, I argue the view that the individual mediates the contradictions between the socially cooperative processes of production and the competitive individualism which legitimates the private appropriation of wealth and income. The link is observable in the schooling process as a pattern of contradictions and tensions mediated by the rhetoric of equality of opportunity. In order to elucidate the link, the processes within the boundaried institutions must be viewed in the context of those changing tensions within the state administrative systems, which reverberate into schools as economic and political constraints. Framed within the ideology of the Flowden Report (1967), middle schooling was set within a discourse which stressed cooperative relationships rather than competitive standards. Since the mid-1970s, administrative policies have heightened the competitive battle for declining resources and attacked the Plowden ideology. Focussing the fieldwork on six middle schools in one local authority, T use an eclectic methodology to relate economic and political policies, generated in the state administrative system, to the situation in the schools between 1979 and 1981. The methodology incorporates a time dimension in order to highlight the tensions as they play upon teachers' changing definitions of the changing situation. I conclude that the intersubjective socio-cultural relations of schooling cannot be properly explained without making explicit the changing tensions in the rule/resource relationships which teachers mediate through their particular institutions.

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In this presentation we will discuss the implications of the so called Nonlinear Shannon Limit. We will compare technologies including new fibres for long haul transmission and techniques to expand the capacity of existing standard single mode fibres.

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Objective-We previously demonstrated that upregulation of intermediate-conductance Ca2+ -activated K+ channels (KCa 3.1) is necessary for mitogen-induced phenotypic modulation in isolated porcine coronary smooth muscle cells (SMCs). The objective of the present study was to determine the role of KCa3.1 in the regulation of coronary SMC phenotypic modulation in vivo using a swine model of postangioplasty restenosis. Methods and Results-Balloon angioplasty was performed on coronary arteries of swine using either noncoated or balloons coated with the specific KCa3.1 blocker TRAM-34. Expression of KCa3.1, c-jun, c-fos, repressor element-1 silencing transcription factor (REST), smooth muscle myosin heavy chain (SMMHC), and myocardin was measured using qRT-PCR in isolated medial cells 2 hours and 2 days postangioplasty. KCa3.1, c-jun, and c-fos mRNA levels were increased 2 hours postangioplasty, whereas REST expression decreased. SMMHC expression was unchanged at 2 hours, but decreased 2 days postangioplasty. Use of TRAM-34 coated balloons prevented KCa3.1 upregulation and REST downregulation at 2 hours, SMMHC and myocardin downregulation at 2 days, and attenuated subsequent restenosis 14 and 28 days postangioplasty. Immunohistochemical analysis demonstrated corresponding changes at the protein level. Conclusion-Blockade of KCa3.1 by delivery of TRAM-34 via balloon catheter prevented smooth muscle phenotypic modulation and limited subsequent restenosis. © 2008 American Heart Association, Inc.

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The growth of heteroepitaxially strained semiconductors at the nanoscale enables tailoring of material properties for enhanced device performance. For core/shell nanowires (NWs), theoretical predictions of the coherency limits and the implications they carry remain uncertain without proper identification of the mechanisms by which strains relax. We present here for the Ge/Si core/shell NW system the first experimental measurement of critical shell thickness for strain relaxation in a semiconductor NW heterostructure and the identification of the relaxation mechanisms. Axial and tangential strain relief is initiated by the formation of periodic a/2 〈110〉 perfect dislocations via nucleation and glide on {111} slip-planes. Glide of dislocation segments is directly confirmed by real-time in situ transmission electron microscope observations and by dislocation dynamics simulations. Further shell growth leads to roughening and grain formation which provides additional strain relief. As a consequence of core/shell strain sharing in NWs, a 16 nm radius Ge NW with a 3 nm Si shell is shown to accommodate 3% coherent strain at equilibrium, a factor of 3 increase over the 1 nm equilibrium critical thickness for planar Si/Ge heteroepitaxial growth. © 2012 American Chemical Society.

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Dr. Alexander Tille (1866–1912) was one of the key-figures in Anglo-German intercultural transfer towards the end of the 19th century. As a lecturer in German at Glasgow University he was the first to translate and edit Nietzsche’s work into English. Writers such as W. B. Yeats were influenced by Nietzsche and used Tille’s translations. Tille’s social Darwinist reading of the philosopher’s oeuvre, however, had a narrowing impact on the reception of Nietzsche in the Anglo-Saxon world for decades. Through numerous publications Tille disseminated knowledge about British authors (e.g., Robert Louis Stevenson, William Wordsworth) in Germany and about German authors (e.g., Johann Wolfgang von Goethe) in Britain. His role as mediator also extended into areas such as history, religion, and industry. During the Boer war, however, Tille’s outspoken pro-German nationalism brought him in conflict with his British host society. After being physically attacked by his students he returned to Germany and published a highly anglophobic monograph. Tille personifies the paradox of Anglo-German relations in the pre-war years, which deteriorated despite an increase in intercultural transfer and knowledge about the respective Other.

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In recent years, offshoring and outsourcing have transformed fundamentally nationally based auto sectors into global networks of design, production and distribution across the global value chains coordinated by the major automotive Original Equipment Manufacturers (OEMs). As manufacturing activities tended to be shifted to low-labour cost locations in Asia, Africa and Latin America, high-end design, R&D, product development have stayed anchored mostly to high-cost and high knowledge-intensive home economy locations (perhaps with the except of some design and styling activities which are often located in major end markets around the world. However, very recently the weaknesses of and risks inherent in such global value chains (GVCs) have been exposed, triggering attempts to rethink their nature and also raising possibilities to reshore some manufacturing activities to home countries. A combination of a more competitive exchange rate (despite the very recent appreciation of sterling), increased transport costs, rising wages in key areas of China, and a greater awareness of supply chain resilience have all contributed to a perceived change in some business fundamentals. The potential for some supply chain relocalisation also links in with the servitisation of manufacturing including the auto sector and shift to a hybrid model where manufacturing and services are increasingly intertwined. However, there are limits as to how far this can go and these raise some important questions and issues over the possible role for industrial policy.