Logic programming in the context of multiparadigm programming: the Oz experience

Oz is a multiparadigm language that supports logic programming as one of its major paradigms. A multiparadigm language is designed to support different programming paradigms (logic, functional, constraint, object-oriented, sequential, concurrent, etc.) with equal ease. This article has two goals: to give a tutorial of logic programming in Oz and to show how logic programming fits naturally into the wider context of multiparadigm programming. Our experience shows that there are two classes of problems, which we call algorithmic and search problems, for which logic programming can help formulate practical solutions. Algorithmic problems have known efficient algorithms. Search problems do not have known efficient algorithms but can be solved with search. The Oz support for logic programming targets these two problem classes specifically, using the concepts needed for each. This is in contrast to the Prolog approach, which targets both classes with one set of concepts, which results in less than optimal support for each class. To explain the essential difference between algorithmic and search programs, we define the Oz execution model. This model subsumes both concurrent logic programming (committed-choice-style) and search-based logic programming (Prolog-style). Instead of Horn clause syntax, Oz has a simple, fully compositional, higher-order syntax that accommodates the abilities of the language. We conclude with lessons learned from this work, a brief history of Oz, and many entry points into the Oz literature.Comment: 48 pages, to appear in the journal "Theory and Practice of Logic Programming

Gap width modification on fully screen-printed coplanar Zn|MnO2 batteries

Fully printed primary zinc-manganese dioxide (Zn|MnO2) batteries in coplanar configuration were fabricated by sequential screen printing. While electrode dimensions and transferred active masses were kept at constant levels, electrode separating gaps were incrementally enlarged from 1 mm to 5 mm. Calendering of solely zinc anodes increased interparticle contact of active material within the electrodes while the porosity of manganese dioxide based electrodes was maintained by non-calendering. Chronopotentiometry revealed areal capacities for coplanar batteries up to 2.8 mAh cm−2. Galvanostatic electrochemical impedance spectroscopy measurements and short circuit measurements were used to comprehensively characterise the effect of gap width extension on bulk electrolyte resistance and charge transfer resistance values. Linear relationships between nominal gap widths, short circuit currents and internal resistances were evidenced, but showed only minor impact on actual discharge capacities. The findings contradict previous assumptions to minimise gap widths of printed coplanar batteries to a sub-millimetre range in order to retain useful discharge capacities. The results presented in this study may facilitate process transfer of printed batteries to an industrial environment

Willem Blok and modal logic

We present our personal view on W.J. Blok's contribution to modal logic

W. Rautenberg

Abstract. We present our personal view on W.J. Blok’s contribution to modal logic

The effect of electrode calendering on the performance of fully printed Zn∣MnO2 batteries

Primary zinc–carbon batteries with a coplanar battery architecture were prepared by screen printing. Prior to battery activation by printing of an acidic zinc chloride electrolyte, printed zinc and manganese dioxide electrodes were compacted by calendering. Material densification of the electodes resulted in electrode layer thickness reduction on both sides, modified micropore surface area and volume on the cathode side. Galvanostatic impedance measurements and chronopotentiometry were used to characterise fabricated batteries with the individually prepared electrode configurations. While calendering of both electrodes of the batteries showed adverse effects by an increase of internal resistances and a reduction of discharge capacities, exclusive calendering of the zinc anode increased the active material utilisation by electrochemical cell reaction and thus the discharge efficiency of the battery