Selective oxidation of n-butane to maleic anhydride under oxygen-deficient conditions over V-P-O mixed oxides

The selective oxidation of n-butane to maleic anhydride over V-P-O mixed oxides was studied under oxygen deficient conditions. The mixed oxides were prepared with P/V atomic ratios ranging from 0.7 to 1.0. Catalysts with P/V <1.0 did not show any selectivity to maleic anhydride formation, regardless of whether or not (VO)2P2O7 was present. For catalysts with P/V = 1.0, containing (VO)2P2O7 and/or the so-called. β-phase, the selectivity was strongly influenced by the actual surface V5+/V4+ ratio. This ratio is determined by the temperature, the crystal phases present in the catalyst and the composition of the gas mixture. Optimal selectivity was obtained at 425°C with 15% butane in air and a butane/oxygen ratio of 0.9

Conditional Reactive Systems

We lift the notion of nested application conditions from graph transformation systems to the general categorical setting of reactive systems as defined by Leifer and Milner. This serves two purposes: first, we enrich the formalism of reactive systems by adding application conditions for rules; second, it turns out that some constructions for graph transformation systems (such as computing weakest preconditions and strongest postconditions and showing local confluence by means of critical pair analysis) can be done very elegantly in the more general setting

Proving Termination of Graph Transformation Systems using Weighted Type Graphs over Semirings

We introduce techniques for proving uniform termination of graph transformation systems, based on matrix interpretations for string rewriting. We generalize this technique by adapting it to graph rewriting instead of string rewriting and by generalizing to ordered semirings. In this way we obtain a framework which includes the tropical and arctic type graphs introduced in a previous paper and a new variant of arithmetic type graphs. These type graphs can be used to assign weights to graphs and to show that these weights decrease in every rewriting step in order to prove termination. We present an example involving counters and discuss the implementation in the tool Grez

Interleague Play And The Big Mac Attack: Estimating The Within-Season Demand For Major League Baseball

Estimation of game-by-game attendance allows the testing of special attendance factors.  In this study the attendance factors of interest are the drawing power of star players (especially homerun hitter Mark McGuire) and particular scheduling circumstances.  The scheduling of interleague games (between the separate National and American League teams) is still a league experiment and deserves close scrutiny with respect to its attendance impact.  Claims by league officials that interleague play increases attendance have not been subject to standard statistical controls.  The opportunity cost of an interleague game was examined by economists before baseball adopted this experiment to increase attendance.

The Attendance Boost Is Over-Rated For Interleague Baseball, And The Big Mac Attack Is A Hit On The Road: All This And More From The Within-Season Demand Model For Major League Baseball

The theory of microeconomic demand is seldom estimated with a rich set of data, yet there is no shortage of statistics in professional sports.&nbsp; Using the sports industry enables economists to extend traditional theory of demand to include products that change daily (the visiting team) as well as the circumstances of their consumption (e.g., the day of the week).&nbsp; In fact the home games of professional sports are never identical from one game to the next.&nbsp; This variation allows one to estimate the quantity response to each of a multitude of factors

Decidability and Expressiveness of Finitely Representable Recognizable Graph Languages

Recognizable graph languages are a generalization of regular (word) languages to graphs (as well as arbitrary categories). Recently automaton functors were proposed as acceptors of recognizable graph languages. They promise to be a useful tool for the verification of dynamic systems, for example for invariant checking. Since automaton functors may contain an infinite number of finite state sets, one must restrict to finitely representable ones for implementation reasons. In this paper we take into account two such finite representations: primitive recursive automaton functors - in which the automaton functor can be constructed on-the-fly by a primitive recursive function -, and bounded automaton functors - in which the interface size of the graphs (cf. path width) is bounded, so that the automaton functor can be explicitly represented. We show that the language classes of both kinds of automaton functor are closed under boolean operations, and compare the expressiveness of the two paradigms with hyperedge replacement grammars. In addition we show that the emptiness and equivalence problem are decidable for bounded automaton functors, but undecidable for primitive recursive automaton functors

Treewidth, Pathwidth and Cospan Decompositions

We will revisit the categorical notion of cospan decompositions of graphs and compare it to the well-known notions of path decomposition and tree decomposition from graph theory. More specifically, we will define several types of cospan decompositions with appropriate width measures and show that these width measures coincide with pathwidth and treewidth. Such graph decompositions of small width are used to efficiently decide graph properties, for instance via graph automata

National Pastime to Dismal Science: Using Baseball to Illustrate Economic Principles

The game of baseball has enormous appeal to students and economists. By using baseball examples in teaching economics, the professor creates the atmosphere of fun while covering substantive topics in economics. This paper enables professors to enrich their principles course with illustrations, outlines, and annotations. The paper also provides the motivation and the suggested content of a special topics course on Baseball Economics, a sure winner in any Economics Department.Economics

A Logic on Subobjects and Recognizability

Abstract. We introduce a simple logic that allows to quantify over the subobjects of a categorical object. We subsequently show that, for the category of graphs, this logic is equally expressive as second-order monadic graph logic (msogl). Furthermore we show that for the more general setting of hereditary pushout categories, a class of categories closely related to adhesive categories, we can recover Courcelle&apos;s result that every msogl-expressible property is recognizable. This is done by giving an inductive translation of formulas of our logic into so-called automaton functors which accept recognizable languages of cospans

Parental wellbeing after diagnosing a child with biliary atresia:A prospective cohort study

PURPOSE: To determine anxiety, stress, and quality of life (QoL) in parents of children who are diagnosed with biliary atresia (BA). METHODS: Parents of BA patients (0-3 years) completed validated questionnaires at three time points: at first hospitalization (T0); 1-2 months post diagnosis (T1); and 2-3 years post diagnosis (T2). Results are presented in medians (min-max). RESULTS: We included 52 parents (age 31 [24-51 y], 31 females) of 30 BA patients. In fathers, neither anxiety nor stress levels significantly differed from reference values. Mothers reported significantly higher anxiety levels compared to reference values (T0: 48 vs 35, p = 0.001; T1: 43 vs 35, p = 0.03; T2: 37 vs 35, p = 0.04), which significantly decreased over time (-23% between T0 and T2: p = 0.04). Stress in mothers was significantly higher at T1 than at T2 (+35%, p = 0.02), but was not significantly different from reference values at each time point (T0: 17 vs 14, p = 0.07; T1: 18 vs 14, p = 0.09; T2: 13 vs 14, p = 0.52).The overall QoL in mothers and fathers was rather unaffected. CONCLUSIONS: Particularly mothers of infants diagnosed with BA report high anxiety levels up to three years after diagnosis. The overall QoL of parents is rather unaffected after diagnosing BA in their child. LEVEL OF EVIDENCE: Level 2