Towards a Formal Account of Reasoning about Evidence: Argumentation Schemes and Generalisations

This paper studies the modelling of legal reasoning about evidence within general theories of defeasible reasoning and argumentation. In particular, Wigmore's method for charting evidence and its use by modern legal evidence scholars is studied in order to give a formal underpinning in terms of logics for defeasible argumentation. Two notions turn out to be crucial, viz. argumentation schemes and empirical generalisations.     

The ARCHIMEDES Network System: a system for searching and accessing information in multiple multimedia sources

The amount of information available to information workers recently has becomeoverwhelming. This confronts information workers with two majorproblems: finding the information needed, and accessing it; they arecalled the search problem and the access problem, respectively. Asthe main result of our research an architecture is specified of anautomated tool that provides integrated support for searching andaccessing multimedia documents that may be located at arbitraryplaces. The architecture contains a database with information aboutthe documents and with thesaurus-like information. The architecturealso contains a browse mechanism and a query mechanism for inspectingthe database. In the design process of the architecture, severalfundamental questions arose, like “What is a document?”and “ What is a medium kind?”. The developed answers tosome of these questions are considered to have a general characterand thus to be useful also outside the scope of the research at hand.The paper concludes with an overview of the current status of theproject and a discussion of future work.     

Notes on the Asymmetric Hydrogenation of Methyl Acetoacetate in Neoteric Solvents

Asymmetric hydrogenation of methyl acetoacetate to methyl (R)-3-hydroxybutyrate by [(R)- RuCl(binap)(p-cymen)]Cl has been studied in methanol-ionic liquid and methanol- dense CO₂ solvent systems. The ionic pairs triethylhexylammonium and 1-methylimidazolium with bis(trifluoromethane sulfonyl) imide and hexafluorophosphates were used. The role of ionic pairs on the kinetic parameters and (enantio)selectivity has been demonstrated. Although the CO₂ expanded methanol system suffered from a reduction in both reaction rate and product selectivity, this changed in the presence of water. The high selectivity of the optimized methanol-CO₂-water-halide system was designed as a consequence of observed additive effects.     

Intensification of the use of ionic liquids as efficient reaction co-solvents in asymmetric hydrogenations

The “Noyori” Ru-BINAP chiral complex is an industrially used homogeneous catalyst for stereoselective hydrogenations providing valuable fine chemicals with high optical yields. Its pseudo-immobilisation with help of various ionic liquids (ILs) represents an alternative to the not very efficient heterogenisation on inorganic supports. Many ILs are commercially readily available or could simply be produced, but in both cases a problem of their purity is encountered. Presence of even trace impurities may either suppress or promote the reaction progress, and most importantly, the parameter of enantioselectivity. The complex treatment of the reaction system must be always accepted whenever a genuine role of an ionic liquid is discussed. For this purpose a well understood reaction system—asymmetric hydrogenation of methyl-3-oxobutanoate (methylacetoacetate/MAA) to methyl-3-hydroxybutanoate (methylhydroxybutyrate/MHB) over the chiral Noyori type Ru-BINAP catalyst in the ethanol-bmimPF₆ reversibly biphasic mixed phase was chosen. Self-prepared bmimPF₆ ionic liquid was exposed to a series of normalized purification steps based on a theoretical semi-mechanistic model. It provided a clear evidence of the number and duration of necessary purification steps together with an effective “value” of each of them. Another important data were collected in the form of pseudo-ternary phase diagrams for all major components including the model impurities.     

Photochemical grafting of acrylated azo dyes onto polymeric surfaces. VII. Kinetics and mechanism of dye-sensitized photoinitiation of some diacrylates

Photoinitiated grafting and graft polymerization of liquid mixtures, adsorbed onto polypropylene, polycaprolactam, and poly(ethylene terephthalate) films, containing one of four acryloxy-substituted aromatic diazenes and one of four diacrylate comonomers, in the presence of 1,2-diphenyl-2,2-dimethoxyethanone as photoinitiator, were investigated kinetically at 30 ± 2°C. Irradiation was carried out polychromatically, with impinging photoenergy from 2.1 × 10^?8 to 20.5 × 10^?8 einstein s^?1 cm^?2; in some of the runs the ultraviolet radiation was filtered. The ratio R between the molar concentration of photoinitiator and the sum of concentrations of dye and diacrylate varied between 0.005 and 0.095; the ratio M between the molar concentration of dye and diacrylate varied between 0.005 and 0.046. The moles of dye and diacrylate n initially deposited per unit apparent polymeric surface S varied between 2 and 74 μmol cm^?2. No selective effect was shown by the presence of dyes in the comonomer mixture. The surface density of grafted molecules at the end of the grafting process was not affected by the photoinitiator concentration (for 0.030 < R < 0.095), by diacrylate or dye concentrations, or by the kind of polymer substrate. This parameter, on the contrary, clearly depended on n/S, and linearly up to n/S ? 30 μmol cm^?2. Quantum efficiencies for the two consecutive kinetic processes of grafting and graft polymerization (Φ₁ and Φ₂, respectively) were evaluated. The dependency of Φ₁ on R, as well as of Φ₂ on n/S, are critically discussed on the basis of the proposed mechanism involving grafting of an oligomeric chain (Φ₁ values up to the order of 10²) followed by a step-by-step graft polymerization (Φ₂ limiting values of the order of unity). The sensitizing effect of acryloxy-substituted aromatic diazenes on both Φ₁ and Φ₂ is evidenced.     

Development and evaluation of a virtual campus on Second Life: The case of SecondDMI

Video games and new communication metaphors are quickly changing today’s young people habits. Considering the actual e-learning scenarios, embedded in a fully technological enabled environment it is crucial to take advantage of this kind of capabilities to let learning process gain best results.     

Development and classroom experimentation of interactive geometry exercises

Abstract Practical experience in the development of computer-based geometry exercises and their use in the classroom for a course on the equation of a straight line are presented. The task of creating the exercises with an authoring system for geometry is described first. Some didactical problems raised by this work are analysed in detail. The production time is estimated and discussed. A classroom experiment with pupils aged 15/16 is then presented and the teacher's organization problems are given (i.e. time spent on technical instruction, time-sharing between theory and practice, tackling the lack of material). Some pedagogical issues are then discussed.     

Complementary circuits based on solution processed low-voltage organic field-effect transistors

The field of organic electronics is advancing quickly towards ultra low-cost, low-end applications and is expected to provide the necessary technology required for flexible/printed electronics. Here we address the need for solution processed low-voltage complementary logic in order to reduce power consumption of organic circuits and hence enable their use in portable, i.e. battery-powered applications. We demonstrate both p- and n-channel solution processed high performance organic field-effect transistors that operate at voltages below |1.5| V. The reduction in operating voltage is achieved by implementing ultra-thin gate dielectrics based on solution processed self-assembled monolayers. This work demonstrates the feasibility of fabricating low-voltage complementary organic circuits by means of solution processing.