Artefact generation in second life with case-based reasoning

Launched in 2003, Second Life is a computer-based pseudo-environment accessed via the Internet. Although a number of individuals and companies have developed a presence (lands) in Second Life, there is no appropriate methodology in place for undertaking such developments. While some existing methods have been adapted by users to their individual needs, this paper explores the development of a method for developing lands specifically within Second Life. This method is based on case-based reasoning (CBR) as this method has a number of similarities with Second Life itself. A system was designed based on CBR with some modifications to work in accordance with Second Life. In this paper, the system and its modifications are discussed and its application to the development of space within Second Life is evaluated. From tracking its progress against previous specifications and future activity, an updated version of the CBR web tool component covering the latest changes and improvements in the tool is introduced here.     

The role of nuclear data for fusion technology studies

Nuclear data are of fundamental importance in studies of nuclear technology. In these studies, experiments to measure cross sections and decay properties and simulations of the design of fission power plants, fusion devices and accelerators are included. The large amount of data required is stored in computer readable formats in data libraries and the most common of these are the general purpose files used for neutronics or transport calculations. These files also contain the standards against which most measurements are made. The other class of libraries are the special purpose ones containing decay data, fission yields and cross section data for dosimetry and activation.This paper gives examples of what data are available and describes their use for various fusion applications. The focus will be on neutron-induced activation data with examples of how the reactions of particular importance can be identified. All data should be accompanied by estimates of the uncertainty. This is best achieved by including covariance data; however, this is extremely challenging and only a subset of the available data has such uncertainty data. The general principles of how covariance matrices are used are outlined.     

Factorial design analysis for dye-sensitized hydrogen generation from water

A factorial design at two levels and four factors has been carried out in order to investigate the potential for hydrogen generation using Eosin Y-sensitized TiO₂/Pt catalyst under visible solar light in presence of triethanolamine (TEOA) as electron donor. The solution pH was found to be a significant parameter, and was maintained at pH 7.0 throughout the investigation. Visible light irradiation time (I-time) showed highest positive effect on hydrogen generation followed by initial Eosin Y concentration (for dye-sensitization) and the TEOA concentration while Pt content (wt %) in TiO₂ showed negative effect toward hydrogen generation. Experimental data were analyzed using both “Pareto analysis” as well as conventional regression analysis techniques. A regression function is proposed that satisfactorily predicts hydrogen generation.     

37—THE EFFECT OF THE MODE OF DRYING ON THE FRACTURE MORPHOLOGY OF JUTE FIBRES: OBSERVATIONS BY SCANNING ELECTRON MICROSCOPY

An investigation is described in which the fracture morphology of jute fibre dried by different means after retting was examined by scanning electron microscopy. It was observed that, in directly dried fibres, an initial transverse crack subsequently develops into an extensive longitudinal one. In indirectly dried fibres, the crack propagation is found to be exclusively across the fibres, like that of the brittle fracture of isotropic materials. The difference in the fracture mode is assumed to be due to the difference between the mode of re-formation of hydrogen bonds in the two cases.     

Characterization of commercial double-walled carbon nanotube material: composition, structure, and heat capacity

A purified commercial double-walled carbon nanotube (DWCNT) sample was investigated by transmission electron microscopy (TEM), thermogravimetry (TG), and Raman spectroscopy. Moreover, the heat capacity of the DWCNT sample was determined by temperature-modulated differential scanning calorimetry in the range of temperature between −50 and 290 °C. The main thermo-oxidation characterized by TG occurred at 474 °C with the loss of 90 wt% of the sample. Thermo-oxidation of the sample was also investigated by high-resolution TG, which indicated that a fraction rich in carbon nanotube represents more than 80 wt% of the material. Other carbonaceous fractions rich in amorphous coating and graphitic particles were identified by the deconvolution procedure applied to the derivative of TG curve. Complementary structural data were provided by TEM and Raman studies. The information obtained allows the optimization of composites based on this nanomaterial with reliable characteristics.