ALBERT

Notes: Abstract: This paper describes a conceptual framework for building expert systems in repair domains. A specific example of the use of this framework in building an expert system for a field service repair problem is given. The example system is designed to assist field service technicians in troubleshooting and repairing electronic systems at the board level. This system, a Field Service Advisor (Fieldserve), is designed (1) to diagnose single or multiple defects in electronic systems, (2) to guide a technician through appropriate repair procedures, (3) to verify diagnoses and monitor repair effectiveness and (4) to maintain records for subsequent evaluation and quality control.

Notes: Assuming that complete information is available about (a) the chemical reactions (mechanism, stoichiometry, thermodynamics, and kinetics) and (b) the turbulent flow field in a reactor (mean velocities and turbulence parameters), we would like to calculate directly the time evolution of the temperature and the concentrations of all species present. No general method is yet available to satisfy this goal. Starting from the phenomena of reaction, molecular diffusion, and laminar deformation in laminated structures, which are formed by the action of vorticity, mixing in liquids at sub-Kolmogorov scales can be quantitatively described. This approach requires the compositions of the fluids incorporated into the vortices to be known. Thus, for example, when a reagent solution (B) is slowly added to a huge volume of a second reagent solution (A) in a stirred tank reactor, fresh B mixes with the average A composition. (Slowly means that the addition time is much greater than the time needed for turbulent and molecular transport to homogenize the tank contents.) Progress of the reactions is then determined essentially by the interaction between the fine-scale mixing (near the Batchelor concentration scale) and the chemical kinetics.A convenient way to evaluate this modeling compares predicted and measured product distributions (or selectivities) for fast multiple reactions. (Up to now, this has been done for dilute solutions, which exhibited concentration, rather than also temperature segregation.) Advantages compared to working with single reactions can include enhanced sensitivity, inclusion of a wider range of flow fields than turbulent pipe flow, e.g., well-stirred systems, and practical relevance of controlling product distributions in the manufacture of chemicals. The effects on the product distributions of fast reactions of operating parameters such as stoichiometric and volumetric feed ratios, reagent concentrations, feed location, impeller speed, size and shape, viscosity, and type of reaction can be well described. Present efforts concentrate on relaxing the assumption of slow feed addition and of describing reactors where not only fine-scale, but also coarse-scale inhomogeneities occur. A simplified model for the engulfment frequency between fluids having different compositions is being evaluated. Some progress has been made, but the way in which fluid elements mix with each other is still not fully known.

Notes: [Auszug] It is shown here how mass spectrometry (MS) can be used for on–line data acquisition in fermentation. MS was applied in this work to analyze gas and liquid phases. Gas phase analysis allows fast and accurate measurement of all gases of interest (O2, N2, CO2, Ar, He etc.). Liquid phase ...

Notes: [Auszug] The problem of whey disposal or its meaningful utilization has plagued the dairy industry for many decades. In some countries, like Switzerland and Norway, where the art of cheese making in small plants still prevails, whey is disposed of locally by pig-feeding or by manufacture of whey cheese. ...

Notes: Summary Petrographic and geochemical data are presented for the Lac Shortt lamprophyre dyke swarm. The primary mineralogy in all samples has been largely destroyed either by alteration at the time of emplacement or by subsequent metamorphism. Most of the dykes are ultramafic lamprophyres. Extended trace element plots (ETP) for these dykes feature a characteristic double dome pattern, with one dome extending between Sr and Zr and the other between Zr and Yb. One ultramafic dyke was selected for detailed study. The ETP and rare earth element (REE) curves for the analyses of this dyke are essentially parallel, indicating the relative immobility of both groups of elements during the subsequent events. Significant correlation coefficients between the high field strength elements using phosphorus as representative of these elements, and the major element concentrations suggests that these were also relatively immobile. Pearce plots and principal component analyses reveal that olivine and apatite fractionation controlled the chemical variation across the control dyke. A plot of Nb anomalies against silica for Precambrian ultramafic and cafe-alkaline lamprophyres reveals two clear groupings—the former has no such anomalies in contrast to the latter which possesses this feature. A calc-alkaline lamprophyre dyke from the Lac Shortt Mine features significant Nb depletion on ETP suggesting that magmas with low Si02 content Si02 = 35.85 weight and chondrite normalized La = 1458) may be related to this catagory of lamprophyre.

Notes: Summary An average chemical composition is proposed for granulite terranes of the lower continental crust based on a data base of 1685 analyses of granulite facies rocks. Both Archean and Post-Archean granulites are included in the file. Discriminant analysis was used to study possible compositional differences between Archean and Post-Archean granulites. Results show no convincing difference between the two age groups using major elements, the REE, or a combination of (K2O, U, Th, Rb and Ba) however a combination of (Cr, Ni, Zr, Nb, V and Co) is promising. The main constraint is the limited number of chemical analyses which contain all the elements of each combination and the difficulty of evaluating the fundamental requirements for use of discriminant analysis which would permit more numerical methods of analyzing the results to be applied.