Decidable and undecidable logics with a binary modality

We give an overview of decidability results for modal logics having a binary modality. We put an emphasis on the demonstration of proof-techniques, and hope that this will also help in finding the borderlines between decidable and undecidable fragments of usual first-order logic.Research supported by the Hungarian National Foundation for Scientific Research grants no. T16448, F17452, T7255. Research of the first author is also supported by a grant of Logic Graduate School of Eötvös Loránd University Budapest     

Measured and non-free vortex design results of axial flow fans

The research is about the determination of developing flow pattern in the axial flow fan impeller. A measuring method and a sizing method of axial flow fans used in a research project have been studied. In this way it has been determined the spatial distribution of static pressure directly behind the impeller as well as the spatial distribution and direction of total pressure in a fixed system to the blade channel. There is an opportunity to identify the high loss region in the impeller: to determine the pressure loss and the hydraulic efficiency at each point. The article shows the results of comparison between the measurement data and the sizing results in the case of one in the agricultural-field utilized cooling fan. The impeller was designed by the help of the fore slanted blades in circumference direction as well as the non-free vortex theory. The basic theories of the design method of the blades and the realization of measurement results are analyzed, too. This paper was presented at the 9^th Asian International Conference on Fluid Machinery (AICFM9), Jeju, Korea, October 16–19, 2007.     

Both Gas Chromatography and an Electronic Nose Reflect Chemical Polymorphism of Juniper Shrubs Browsed or Avoided by Sheep

Chemical polymorphism may contribute to variation in browsing damage by mammalian herbivores. Earlier, we demonstrated that essential oil concentration in juniper, Juniperus communis, was negatively associated with herbivore browsing. The aim of the present study was to characterize the volatile chemical composition of browsed and non-browsed J. communis. By using either gas chromatography with flame ionization detection (GC-FID) or an electronic nose device, we could separate sheep-browsed or non-browsed juniper shrubs by their essential oil pattern and complex odor matrix. The main components of the essential oil from J. communis were monoterpenes. We distinguished three chemotypes, dominated either by α-pinene, sabinene, or δ-3-carene. Shrubs belonging to the α-pinene- or sabinene-dominated groups were browsed, whereas all individuals with the δ-3-carene chemotype were unused by the local herbivores. The electronic nose also separated the browsed and non-browsed shrubs indicating that their odor matrix could guide sheep browsing. Responses of sheep could integrate the post-ingestive effects of plant secondary metabolites with sensory experience that stems from odor–phytotoxin interactions. Chemotype diversity could increase the survival rate in the present population of J. communis as certain shrubs could benefit from relatively better chemical protection against the herbivores.     

Sources of doubt: actors,forums, and language of climate change skepticism

Scientometrics - The paper investigates the reference corpus of a climate change contrarian report. We categorized the journal abstracts according to the endorsement positions on anthropogenic...     

Insights on Antioxidant Assays for Biological Samples Based on the Reduction of Copper Complexes—The Importance of Analytical Conditions

Total antioxidant capacity assays are recognized as instrumental to establish antioxidant status of biological samples, however the varying experimental conditions result in conclusions that may not be transposable to other settings. After selection of the complexing agent, reagent addition order, buffer type and concentration, copper reducing assays were adapted to a high-throughput scheme and validated using model biological antioxidant compounds of ascorbic acid, Trolox (a soluble analogue of vitamin E), uric acid and glutathione. A critical comparison was made based on real samples including NIST-909c human serum certified sample, and five study samples. The validated method provided linear range up to 100 µM Trolox, (limit of detection 2.3 µM; limit of quantification 7.7 µM) with recovery results above 85% and precision <5%. The validated developed method with an increased sensitivity is a sound choice for assessment of TAC in serum samples.     

Ecological Evaluation of the Baja-Bezdan Canal (Hungary–Serbia) for Reconstruction Planning

Complying with the objectives of the European Union Water Framework Directive, the water management organisations of Hungary and Serbia launched a common project in 2010 in order to improve the status of the channel crossing the national border. During reconstruction planning they intended to take ecological aspects into consideration. Therefore the evaluation of ecological state has been carried out for the Baja-Bezdan channel complemented by on-the-spot monitoring and biological examinations. Such a detailed survey of the channel has no precedent to date. Besides the evaluation, ecology-based proposals were phrased, which not only serve the sustainable functioning of the channel, but also help to preserve its flora and fauna.     

Cleaning Interval Graphs

We investigate a special case of the Induced Subgraph Isomorphism problem, where both input graphs are interval graphs. We show the NP-hardness of this problem, and we prove fixed-parameter tractability of the problem with non-standard parameterization, where the parameter is the difference |V(G)|?|V(H)|, with G and H being the larger and the smaller input graph, respectively. Intuitively, we can interpret this problem as “cleaning” the graph G, regarded as a pattern containing extra vertices indicating errors, in order to obtain the graph H representing the original pattern. We also prove W[1]-hardness for the standard parameterization where the parameter is |V(H)|.     

Obtaining a Planar Graph by Vertex Deletion

In the?k-Apex problem the task is to find at most?k vertices whose deletion makes the given graph planar. The graphs for which there exists a solution form a minor closed class of graphs, hence by the deep results of Robertson and Seymour (J.?Comb. Theory, Ser.?B 63(1):65–110, 1995; J.?Comb. Theory, Ser.?B 92(2):325–357, 2004), there is a cubic algorithm for every fixed value of?k. However, the proof is extremely complicated and the constants hidden by the big-O notation are huge. Here we give a much simpler algorithm for this problem with quadratic running time, by iteratively reducing the input graph and then applying techniques for graphs of bounded treewidth.