Predictive closed-loop power control for frequency-division duplexwireless systems

A novel method for performing uplink closed-loop power control is proposed, namely with uplink prediction and downlink-derived predictor coefficients. The lack of correlation between the fading processes on uplink and downlink (due to frequency division duplex and frequency selective fading) is circumvented by using the uplink fading history, together with a set of link-independent, autoregressive coefficients     

Spectroscopic evidence for the bulk polymerization of N-vinyl carbazole in the presence of single-walled carbon nanotubes

The bulk polymerization reaction of N-vinylcarbazole (VK) at 70 °C in the presence of single-walled carbon nanotubes (SWNTs) leads to a new composite, whose optical properties were studied by photoluminescence (PL), surface enhanced Raman scattering (SERS) and Fourier transform infrared (FTIR) spectroscopies. A dramatic reduction of the poly(N-vinylcarbazole) (PVK) PL efficiency and a change in the vibrational structure of the PL spectrum of this polymer were observed by adding SWNTs to the synthesis mixture. Steric hindrance effects were evidenced both in SERS spectra of the VK when it interacts mechanico-chemically with SWNTs and in FTIR spectra of the un-doped PVK/SWNTs' composites. Cyclic voltammetry was used to demonstrate the doping process of PVK in PVK/SWNTs' composite.     

Secondary data — the Poor Relative of Business Continuity

Cable & Wireless Plc acquired Exodus on the 1st February 2002.You think you’ve got BCP covered because you take regular backups and store them safely off site and perhaps even encrypt them … Think again. There is a whole plethora of devices and programs that facilitate your users accessing that data after you have dutifully restored it from your backup medium of choice. These facilitators contain secondary data and this data needs backing up and security measures as well, otherwise your primary data will resemble a newly restored vintage car: great looks, but no leaded gasoline available to run on.     

Polymer-Derived SiOC/ZrO2 Ceramic Nanocomposites with Excellent High-Temperature Stability

Polymer-derived SiOC/ZrO₂ ceramic nanocomposites have been prepared using two synthetic approaches. A commercially available polymethylsilsesquioxane (MK Belsil PMS) was filled with nanocrystalline zirconia particles in the first approach. The second method involved the addition of zirconium tetra( n -propoxide), Zr(OⁿPr)₄, as zirconia precursor to polysilsesquioxane. The prepared materials have been subsequently cross-linked and pyrolyzed at 1100°C in argon atmosphere to provide SiOC/ZrO₂ ceramics. The obtained SiOC/ZrO₂ materials were characterized by means of X-ray diffraction, elemental analysis, Raman spectroscopy as well as transmission electron microscopy. Furthermore, annealing experiments at temperatures from 1300° to 1600°C have been performed. The annealing experiments revealed that the incorporation of ZrO₂ into the SiOC matrix remarkably increases the thermal stability of the composites with respect to crystallization and decomposition at temperatures exceeding 1300°C. The results obtained within this study emphasize the enormous potential of polymer-derived SiOC/ZrO₂ composites for high-temperature applications.     

Fabrication of Sub‐10 nm Metallic Lines of Low Line‐Width Roughness by Hydrogen Reduction of Patterned Metal–Organic Materials

The fabrication of very narrow metal lines by the lift‐off technique, especially below sub‐10 nm, is challenging due to thinner resist requirements in order to achieve the lithographic resolution. At such small length scales, when the grain size becomes comparable with the line‐width, the built‐in stress in the metal film can cause a break to occur at a grain boundary. Moreover, the line‐width roughness (LWR) from the patterned resist can result in deposited metal lines with a very high LWR, leading to an adverse change in device characteristics. Here a new approach that is not based on the lift‐off technique but rather on low temperature hydrogen reduction of electron‐beam patterned metal naphthenates is demonstrated. This not only enables the fabrication of sub‐10 nm metal lines of good integrity, but also of low LWR, below the limit of 3.2 nm discussed in the International Technology Roadmap for Semiconductors. Using this method, sub‐10 nm nickel wires are obtained by reducing patterned nickel naphthenate lines in a hydrogen‐rich atmosphere at 500 °C for 1 h. The LWR (i.e., 3 σ_LWR) of these nickel nanolines was found to be 2.9 nm. The technique is general and is likely to be suitable for fabrication of nanostructures of most commonly used metals (and their alloys), such as iron, cobalt, nickel, copper, tungsten, molybdenum, and so on, from their respective metal–organic compounds.