1,721,806 research outputs found
Aspects of the coastal dynamics of Poole and Christchurch Bays, Dorset
No full textThe research detailed in this thesis attempts to illustrate to the coast protection planner the importance of acquiring a detailed knowledge of local coastal processes prior to the design and construction of coast protection schemes, and seeks to emphasise the desirability of abandoning the present segmented approach to coast protection planning in favour of a more closely integrated planning process. Aspects of both the past and the present coastal dynamics of Poole and Christchurch Bays are examined and used to predict probable future short and long term coastal changes. The chronological development of the two bays is discussed, and the significance of various submarine features assessed. The past and most probable future evolution of the plan geometry of the two bays is considered in conjunction with the general concepts of log-spiral (crenulate) shaped bay development and stability. Some fundamental problems experienced with the application of the model based concepts to natural bays are discussed. The coastal dynamics of Hengistbury Long Beach, Poole Bay are considered in detail, both with respect to the coastal processes which operate in the immediate vicinity of the beach and with respect to the dynamics of the Poole and Christchurch Bay physiographic unit as a whole. The results of a single sand, and two shingle tracer experiments are described. The major limitations of existing shingle tracer techniques are discussed and details are given of a new aluminium pebble tracer, designed specifically to overcome these limitations. The considerable scope believed to exist for the further development and application of the technique is described. The value of tracer experiments in general as a means of determining volumetric rates of longshore sediment transport is assessed. Finally, an appraisal is given of the current coast protection planning process, and of the future requirements for coast protection within Poole and Christchurch Bays. The requirement for further research is also discussed.</p
Peach Ceri — West Indian Migration to Britain; Wright Peter L. — The Coloured Worker in British Industry
No full textT. G. Peach Ceri — West Indian Migration to Britain; Wright Peter L. — The Coloured Worker in British Industry. In: Population, 25ᵉ année, n°1, 1970. pp. 175-176
Peach Ceri — West Indian Migration to Britain; Wright Peter L. — The Coloured Worker in British Industry
No full textT. G. Peach Ceri — West Indian Migration to Britain; Wright Peter L. — The Coloured Worker in British Industry. In: Population, 25ᵉ année, n°1, 1970. pp. 175-176
Novel chiral cyclopentadienyl metal complexes
No full textThe synthesis and applications of transition metal complexes containing cyclopentadienyl-phosphorus and amine bidentate ligands have been reviewed and the work of other research groups discussed. The synthesis of the known three-carbon linked ligand rac[3-cyclohexyl-3-(3H-iden-1-yl)propyl]-diphenyl-phosphine 201 has been optimised. This involves the novel 1,4-catalytic addition of idenyl lithium to an α,β-unsaturated ester. Complexation with RuC12(PPh3)3 to form its ruthenium(II) complex rac-401, has also been optimised. Complete control over the induction of chirality at the metal centre and high induction of planar chirality (66% d.e.) remain. Its cationic version rac-402 has been synthesised, however, the attempted synthesis of its tetrahydroindenyl analogue rac-403 failed. The novel three-carbon linked chiral ligand (S)-[3-cyclohexyl-3-(3H-iden-1-yl)-propyl]diphenyl-phosphine, (S)-201 has been synthesised with an overall yield of 26% after 7 steps in 98% e.e. This involved initial asymmetric hydrogenation of 330 using a chiral bidentate phosphine-ruthenium complex and was achieved in 81% yield and 99% e.e. This displacement of the secondary mesylate 335 with idene, via an SN2 mechanism, was the key step with enantiomeric purity being maintained. (S)-201 has been complexed with RuC12(PPh3)3 to form its ruthenium(Ii) complex (S)-401, with 67% d.e. induction of planar chirality and complete control over the induction of chirality at the metal centre. Its cationic version (S)-402 has been synthesised, however, the attempted synthesis of its tetrahydroindenyl analogue (S)-403 failed. X-ray structures of five of the above organometallic complexes have been obtained, as well as size X-ray structures of intermediates formed during the syntheses of their ligands. (Formulae not provided).</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Investigation of damage in laminated carbon fibre composites using high resolution computed tomography
No full textLaminated fibre reinforced polymer matrix composites have been used in design and manufacture for more than 50 years, exploiting desirable material properties such as high specific strength and stiffness, enabling large weight savings to be made on structural components. To take full advantage of this class of materials a comprehensive knowledge of behaviour under different service conditions is required. This thesis illustrates the degree to which this is currently achieved, and describes the motivation and progression of an experimental and theoretical analysis of the static damage growth in carbon fibre reinforced polymers.Notched carbon fibre-epoxy cross-ply composite samples have been manufactured and loaded in uni-axial tension. Synchrotron radiation computed tomography (SRCT) has been used to characterise in 3-D the initiation and evolution of damage during in situ loading. Characteristic splitting, off-axis matrix cracking, interlaminar cracking and fibre failure within the samples were identified and the interaction of the damage mechanisms during crack growth has been evaluated. Splitting in the plies aligned with the loading direction was studied in greater detail, including measurements of crack opening displacement and shear deformation at crack flanks.3-D finite element models of splitting have been developed based on the observed damage and specimen microstructure from the SRCT results. Thermal residual stress and mechanical loading conditions were simulated for comparison with the experimental findings. Effects of local microstructural inhomogeneities were also embedded in models of varying complexity to assess the degradation of the results or model predictions due to simplifications or homogenisation. Significant discrepancy was found between the measured experimental data and finite element predictions due to simplifications in the model. Likely candidates for the over-prediction of crack growth include the effects of transverse ply cracks, delaminations and the lack of symmetrical damage formulation. Of particular significance is the confirmation that, via qualitative observations and quantitative data extraction, SRCT has facilitated the first known instance of direct full field comparison of model predictions for composite damage for a practical engineering layup
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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