Pictorial Socratic dialogue and conceptual change

Counter-examples used in a Socratic dialogue aim to provoke reflection to effect conceptual changes. However, natural language forms of Socratic dialogues have their limitations. To address this problem, we propose an alternative form of Socratic dialogue called the pictorial Socratic dialogue. A Spring Balance System has been designed to provide a platform for the investigation of the effects of this pedagogy on conceptual changes. This system allows learners to run and observe an experiment. Qualitative Cartesian graphs are employed for learners to represent their solutions. Indirect and intelligent feedback is prescribed through two approaches in the pictorial Socratic dialogue which aim to provoke learners probe through the perceptual structural features of the problem and solution, into the deeper level of the simulation where Archimedes’ Principle governs

In situ analysis of CO during chemisorption and oxidation on graphite: Supported Pt by FTIR-microspectrometry

For chemisorption and oxidation on Pt/HOPG (highly-orientated pyrolytic) graphite, reflectance Fourier Transform Infrared (FTIR)-microspectrometry reveals a variable state and reactivity for CO. Even for model surface science systems, where surface heterogeneity is minimal, surface diffusion may be too slow relative to the reaction rate to avoid segregation of reactants into surface islands under steady-state conditions. Thus in CO oxidation on Pt (where the relevant surface diffusion coefficients are such that D sub O less than D sub CO) then reactant CO islands exists at the perimeters of which the surface reaction is thought to occur. Furthermore CO can chemisorb on metals in linear and bridge forms to extents which vary with precise faces predominantly exposed coverage, etc. Infrared has long been used to probe the nature of adsorbed CO on model film and heterogeneous surfaces, but it may now be that FTIR-microspectrometry will allow the state of this adsorbate and reactant to be investigated with a spatial resolution of 4.4 microns on model (and real) catalytic surfaces

Fourier transform infrared cell for surface studies at controlled temperatures and in controlled atmospheres with time resolution and spatial resolution

A new micro-Fourier transform infrared cell has been constructed and evaluated using (i) the transformation of aurichalcite crystals at 298-475 K, (ii) the adsorption/desorption of pyridine on a Cu2O/ZnO junction, and (iii) the adsorption of CO on Pt/alumina pellets; it enables spatial and time resolution of processes in such diverse samples held at known thermal and baric conditions. The potential of this cell in catalytic and analytical science is considered

Interpretation of dispersion relations for bounded systems

Constructing normal modes for bounded systems from infinite dispersion relation roots for interpretation of plasma wave and instability studies on finite cylinder

Sediment transport and erosion in the Fourchon area of Lafourche parish

NASA aerial photography in the form of color infrared and color positive transparencies is used as an aid in evaluating the rate and effect of erosion and sediment transport in Bay Champagne Louisiana

Analysis of Pt/SnO(sub x) during catalysis of CO oxidation

Temperature-programmed reduction using 6kPaH2 suggests that a sample consisting of 3 percent Pt supported directly on SnO2 is, under conditions of catalysis of CO oxidation used here, best represented as 3 percent Pt/SnO sub x, since the support is likely to partially reduced, probably in the vicinity of the metal/oxide interface. Catalytic measurements at 421 to 424 K show that this 3 percent Pt/SnO sub x is significantly more active per unit area of Pt than 6 percent Pt/SiO2 in catalyzing the oxidation of CO. In situ micro-FTIR reveals that while the latter has predominantly linearly bound CO on the surface under reaction conditions, the Pt/SnO sub x also has a species absorbing at 2168 cm(exp -1) which may be CO upon Pt in a positive oxidation state or weakly chemisorbed CO on zero-valent Pt. This may be directly involved in the low temperature oxidation of CO on the Pt/SnO sub x, since being weakly held the activation energy for its surface diffusion to the metal/oxide interface will be low; such mobile species could allow the high rates of surface transport and an increase in the fraction of the surface over which the CO oxidation occurs. FTIR also reveals carbonate-type species on the P/SnO sub c surface

Calorimetry, activity, and micro-FTIR analysis of CO chemisorption, titration, and oxidation on supported Pt

The value of in situ analysis on CO chemisorption, titration and oxidation over supported Pt catalysts using calorimetry, catalytic and micro-FTIR methods is illustrated using silica- and titania-supported samples. Isothermal CO-O and O2-CO titrations have not been widely used on metal surfaces and may be complicated if some oxide supports are reduced by CO titrant. However, they can illuminate the kinetics of CO oxidation on metal/oxide catalysts since during such titrations all O and CO coverages are scanned as a function of time. There are clear advantages in following the rates of the catalyzed CO oxidation via calorimetry and gc-ms simultaneously. At lower temperatures the evidence they provide is complementary. CO oxidation and its catalysis of CO oxidation have been extensively studied with hysteresis and oscillations apparent, and the present results suggest the benefits of a combined approach. Silica support porosity may be important in defining activity-temperature hysteresis. FTIR microspectroscopy reveals the chemical heterogeneity of the catalytic surfaces used; it is interesting that the evidence with regard to the dominant CO surface species and their reactivities with regard to surface oxygen for present oxide-supported Pt are different from those seen on graphite-supported Pt

Designing and specifying mobility within the multiagent systems engineering methodology

Recently, researchers have created many platforms and applications for mobile agents; however, current Agent-Oriented Software Engineering (AOSE) methodologies have yet not fully integrated the unique properties of these mobile agents. This paper attempts to bridge the gap between current AOSE methodologies and mobile agent systems by incorporating mobility into the established Multiagent Systems Engineering (MaSE) methodology. We accomplished this by adding a move command to the MaSE analysis models and then defined the required transformations to incorporate the required functionality into the design. Finally, we translated the design models into Java-based agents that operate within a mobile agent environment. 1

Rapid Karst Development in an English Quartzitic Sandstone

 Na izdankih Fellskih peščenjakov v pokrajini Northumberland v Angliji, se pojavlja več kraških oblik, med njimi tudi jame. Kraške oblike so nastale v holocenu, saj je bilo območje v Devenzijski hladni dobi pokrito z ledenikom. Predvidevamo, da je nastanek teh oblik povezan z incepcijo tektonske dejavnosti in hitro arenizacijo (selektivnim preperevanjem vlažnih) kamnitih površin. V članku razpravljamo tudi o omejenosti splošno sprejetih definicij termina kras. Many karst features, including caves, have been found in the outcrop of the Fell Sandstone in Northumberland, England. These features are Holocene in age, since the area was glaciated during the Devensian cold stage. It is suggested that tectonic inception and selective arenisation of rock faces that remain damp are responsible for these karst features. The limitations of textbook definitions of the term karst are discussed