351 research outputs found
The evaluation challenge
For years writers concerned with information literacy (IL) – essentially the knowledge, skills and understanding needed to find and use information effectively – have stressed the importance of learners evaluating the material with which they come into contact whilst searching. As many commentators explain, the need to make sound judgements has become especially important today, since so much information searching now involves the World Wide Web. The evaluative framework proposed in this article was designed with the aim of helping to narrow the gap between discoveries emerging from research and the teaching of IL
Young people and the evaluation of information on the World Wide Web: Principles, practice and beliefs
A recurrent theme in LIS literature is the tendency of young people not to evaluate rigorously the information with which they come into contact. Although many information literacy models stress the need to take a critical approach, the reality of behaviour is often very different. Recent research conducted in an English high school has explored the importance that teenagers attach to ten particular evaluative criteria. 149 youngsters contributed data via an online questionnaire. Participants felt that information on the Web should be current/topical, free from spelling and grammatical errors and easily verifiable elsewhere but authorship was much less of a priority to them. The findings are likely to be of special relevance to information literacy teachers who are defining priorities for their own programmes
Facilitating pupil thinking about information literacy
Whilst information literacy is frequently taught through the imposition on learners of an established framework, this paper suggests a different approach by taking a lead from James Herring’s ideas. Specifically, it provides guidance to school-based information professionals who would like to encourage their pupils to devise their own flexible, information literacy models which are unique to them. Drawing on existing material in information science and wider thought, it proposes areas for coverage and considers how information professionals may support the dynamic process of model construction. It is recommended that those who are intent on facilitating the creation of personal information literacy models help pupils to identify the roles they take on in their lives, to reflect on the information needs that result, to ascertain the information they require in particular situations, to explore their information-seeking activities, to consider means by which information can be captured and to give thought as to how the information they have accessed may be used. This framework is, however, by no means rigid and readers are, of course, free to make their own adjustments
Thermodynamically stable lithium silicides and germanides from density-functional theory calculations
Density-functional-theory (DFT) calculations have been performed on the Li-Si
and Li-Ge systems. Lithiated Si and Ge, including their metastable phases, play
an important technological r\^ole as Li-ion battery (LIB) anodes. The
calculations comprise structural optimisations on crystal structures obtained
by swapping atomic species to Li-Si and Li-Ge from the X-Y structures in the
International Crystal Structure Database, where X={Li,Na,K,Rb,Cs} and
Y={Si,Ge,Sn,Pb}. To complement this at various Li-Si and Li-Ge stoichiometries,
ab initio random structure searching (AIRSS) was also performed. Between the
ground-state stoichiometries, including the recently found LiSi
phase, the average voltages were calculated, indicating that germanium may be a
safer alternative to silicon anodes in LIB, due to its higher lithium insertion
voltage. Calculations predict high-density LiSi and LiGe
layered phases which become the ground state above 2.5 and 5 GPa
respectively and reveal silicon and germanium's propensity to form dumbbells in
the LiSi, stoichiometry range. DFT predicts the stability of
the LiGe , LiGe and LiGe
phases and several new Li-Ge compounds, with stoichiometries LiGe,
LiGe, LiGe and LiGe.Comment: 10 pages, 5 figure
Product innovation in a new technology based firm
This thesis examines the "state of the art" of product innovation in new technology In the UK. The roles in innovation attributed to small and large firms are examined. Growing attention is being focused upon the small firm sector as a seedbed for Innovation and government policy has been changing to encourage the entrepreneurial new technology based firm (NTBF). The novel perspective of this research results from working in such a firm. It provides a longitudinal study of the management of innovation in conjunction with the corporate strategy of the firm. Given that the researcher was a participant and observer in the firm studied, the research is akin to action research in methodology but is better described as grounded theory. Theoretical concepts are drawn from the prescriptive literature describing corporate strategy, and from the empirical literature which has evaluated new product success and failure. Models of the Innovation process are discussed and appropriate strategies and reasons for product innovation failure in NTBFs are described. The strategy, structure and new product development progress of the company are examined, using both the researcher's observations and company documents. This provides information on the methods and practices adopted for product innovation in a NTBF. The thesis analyses the performance of the firm In terms of product innovation. The models and strategies derived from the literature are then tested in the light of the experience of the company. Conclusions are drawn regarding strategies for innovation in NTBFs and about the innovation process in general. The importance of a NTBF adopting a synergistic strategy is shown. Links are established between the existence of synergy in the strategy and coupling in the management of innovation. Innovation is shown to be a laterally interdisciplinary exercise and therefore the "pipeline model" Is criticised. Finally a set of guidelines Is produced for the managers of NTBFs
Hydrogen/nitrogen/oxygen defect complexes in silicon from computational searches
Point defect complexes in crystalline silicon composed of hydrogen, nitrogen,
and oxygen atoms are studied within density-functional theory (DFT). Ab initio
Random Structure Searching (AIRSS) is used to find low-energy defect
structures. We find new lowest-energy structures for several defects: the
triple-oxygen defect, {3O}, triple oxygen with a nitrogen atom, {N, 3O}, triple
nitrogen with an oxygen atom, {3N,O}, double hydrogen and an oxygen atom,
{2H,O}, double hydrogen and oxygen atoms, {2H,2O} and four
hydrogen/nitrogen/oxygen complexes, {H,N,O}, {2H,N,O}, {H,2N,O} and {H,N,2O}.
We find that some defects form analogous structures when an oxygen atom is
replaced by a NH group, for example, {H,N,2O} and {3O}, and {H,N} and {O}. We
compare defect formation energies obtained using different oxygen chemical
potentials and investigate the relative abundances of the defects.Comment: 9 pages, 13 figure
Energetics of hydrogen/lithium complexes in silicon analyzed using the Maxwell construction
We have studied hydrogen/lithium complexes in crystalline silicon using
density-functional-theory methods and the ab initio random structure searching
(AIRSS) method for predicting structures. A method based on the Maxwell
construction and convex hull diagrams is introduced which gives a graphical
representation of the relative stabilities of point defects in a crystal and
enables visualization of the changes in stability when the chemical potentials
are altered. We have used this approach to study lithium and hydrogen
impurities in silicon, which models aspects of the anode material in the
recently-suggested lithium-ion batteries. We show that hydrogen may play a role
in these anodes, finding that hydrogen atoms bind to three-atom lithium
clusters in silicon, forming stable {H,3Li} and {2H,3Li} complexes, while the
{H,2Li} complex is almost stable.Comment: (5 pages, 4 figures
Lithiation of silicon via lithium Zintl-defect complexes
An extensive search for low-energy lithium defects in crystalline silicon
using density-functional-theory methods and the ab initio random structure
searching (AIRSS) method shows that the four-lithium-atom substitutional point
defect is exceptionally stable. This defect consists of four lithium atoms with
strong ionic bonds to the four under-coordinated atoms of a silicon vacancy
defect, similar to the bonding of metal ions in Zintl phases. This complex is
stable over a range of silicon environments, indicating that it may aid
amorphization of crystalline silicon and form upon delithiation of the silicon
anode of a Li-ion rechargeable battery.Comment: 4 pages, 3 figure
Relative effectiveness of robot-assisted and standard laparoscopic prostatectomy as alternatives to open radical prostatectomy for treatment of localised prostate cancer : a systematic review and mixed treatment comparison meta-analysis
© 2013 The Authors. BJU International © 2013 BJU International.Peer reviewedPublisher PD
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