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1 – 10 of over 33000G.G. Chowdhury and Sudatta Chowdhury
A number of digital libraries have been set up in the course of various research and development activities in different parts of the world during the last few years. How do these…
Abstract
A number of digital libraries have been set up in the course of various research and development activities in different parts of the world during the last few years. How do these digital libraries fair in terms of information retrieval features? This paper looks into this question by reviewing the information retrieval features of 20 digital libraries chosen from around the globe. The first part of the paper briefly describes the features of the chosen digital libraries in terms of their nature and content. The second part looks into the information retrieval features of each digital library. Unique features of some digital libraries have been indicated. Major areas of research that would improve the information retrieval features of the future digital libraries have been indicated.
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Thomas Durand and Marie Dubreuil
Technology has always inspired social change, but its scale and complexity have begun to bewilder even the politicians and policymakers. Several recent national foresight studies…
Abstract
Technology has always inspired social change, but its scale and complexity have begun to bewilder even the politicians and policymakers. Several recent national foresight studies point to a need for socio‐organizational or “soft” technologies to help Europe manage change and respond to major new economic opportunities. Research is required in fields such as neuro‐linguistic programming, the psychology of knowledge management and the ergonomics of the man‐machine interface. “Electronic pets” showed that we can learn to love machines – now the challenge is to embed technology in such a way as to marry science with society.
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E.E. Abd El Aal, A. Abd El Aal and S.M. Abd El Haleem
The effect of the addition of aggressive salts such as LiCl, NaCl, KCl, RbCl and MgCl2 on the steady‐state potential of a Zn electrode previously equilibrated in a passivating…
Abstract
The effect of the addition of aggressive salts such as LiCl, NaCl, KCl, RbCl and MgCl2 on the steady‐state potential of a Zn electrode previously equilibrated in a passivating chromate solution is established. S‐shaped curves are obtained for the variation of the steady‐state potential with the quantity of aggressive salt added. For each inhibitor concentration, Cinh, the addition of aggressive ions up to a certain concentration has no effect on the passivity of Zn. However, higher Cl ion concentration causes destruction of the passive film and initiation of pitting corrosion. Destruction of passivity occurs after an induction period which decreases with the increase in the concentration of the attacking ion and/or the decrease in that of the inhibiting ions. The concentration of aggressive ion, Cagg, that can be tolerated by a certain concentration of the inhibiting ions, Cinh, is given by the relation : log Cinh =K + n log CCl−, where K and n are constants. The efficiency of these salts in initiating pitting corrosion increases in the order RbCl ≤ MgCl2, ≤ KCl < NaCl < LiCl. The change in the degree of aggressivity of these salts could be attributed either to the incorporation of the cations in the passive film or to their effect on pH.