Recent Decisions

Comments on recent decisions by John F. Murray, William C. Rindone, Eugene G. Griffin, John G. Curran, John P. Callahan, and William J. Ragan

Recent Decisions

Comments on recent decisions by William C. Rindone, Ray F. Drexler, Eugene G. Griffin, Ronald Patrick Smith, and John G. Curran

The finite index basis property

We describe in this paper a connection between bifix codes, symbolic dynamical systems and free groups. This is in the spirit of the connection established previously for the symbolic systems corresponding to Sturmian words. We introduce a class of sets of factors of an infinite word with linear factor complexity containing Sturmian sets and regular interval exchange sets, namely the class of tree sets. We prove as a main result that for a uniformly recurrent tree set S, a finite bifix code X on the alphabet A is S-maximal of S-degree d if and only if it is the basis of a subgroup of index d of the free group on

Passenger Mobility in a Discontinuous Space: Modelling Access/Egress to Maritime Barrier in a Case Study

The present study analyses a transport system in a discontinuous space. Classical specifications of transport models cannot be applied directly when evaluating the influence of territorial discontinuity and related barriers on user behaviour. Adjustments are required for this specific case because studies relative to discontinuous spaces are limited. The influence concerns the different travel components (access, barrier, on board, and egress) and could impact travel choices (departure time, destination, mode, and path). In this paper, the models refer to access and egress components with a focus on the mode of travel choice level. The paper focusses on the influence of discontinuity, introducing some adjustments to the classical demand models used to simulate discontinuity crossing. The main variables influencing the user’s choice, and their relative weight in discontinuous space, are investigated. These elements are fundamental for any planning and design procedures to improve the quality of mobility. In the paper, the case study of the Strait of Messina in southern Italy is analysed. In this case, the barrier is constituted by the sea that physically separates the two shores. In this work, only strait crossings via hydrofoil, from Reggio Calabria to Messina, are considered in random sample interviews

Small Angle X-ray Scattering and Transmission Electron Microscopy of Water Containing Phase Separated Soda Lime Silica Glasses

The phase separation characteristics of a soda-lime-silica glass composition located in the metastable liquid immiscibility region were studied as a function of water content in the glass structure. The water content was varied by the batching process, using dry and gel batches, and by melting under different water vapour partial pressures. The glasses were analysed for their water contents which were evaluated as a function of the raw materials and melting atmosphere. Variations in the phase separation characteristics as a function of water content were observed by small angle x-ray scattering measurements and transmission electron microscopy. The most profound effect was an increase in nucleation frequency with increasing water content in the glass