Structural, electronic and optical properties of CuInS2 single crystals.

The single crystals of MSe2 (M = Nb, Mo, Ta and W) were grown through vapour phase by screw dislocation mechanism. The development of stresses by variation in high temperature of the dual zones involved, resulting into slip lines and vapour inclusion, might possibly lead to generation of favourable screw dislocation sites. The morphology of as grown crystals has been studied by TEM. From this analysis, the general rule that nanoparticles of compounds, crystallizing in layered structures tend to form closed shapes. The formation of closed shapes reduces the number of dangling bonds on the periphery of the layers.

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In this two part paper, we describe the design and implementation of a secure online e-auction system called SeTiA (Secure TIFR Auction System).Various protocols have been developed/adapted to cater to different auction mechanisms, negotiations, payments, certified email, etc. Specifically, the system includes the classical auctions (English, Dutch, sealed bid first and second price), multi-unit bids, combinational (bundle) auctions, and call markets (wherein buyers and sellers are matched repeatedly over time). Further, the system provides features such as bid confidentiality (open or sealed), bid cancellations, identity confidentiality, auction closure (expiration time or timeout). With the growing number of online transactions over the Internet, security of negotiations and transactions is a serious issue. In this system, we achieve various levels of security using the SPKI/SDSI framework, as well as secure payment systems. In the first part of the paper, we shall discuss new algorithmic mechanisms for multi-unit and combinational auctions, along with matching and pricing issues.