Resource Sharing via Capability-Based Multiparty Session Types

Multiparty Session Types (MPST) are a type formalism used to model communication protocols among components in distributed systems, by specifying type and direction of data transmitted. It is standard for multiparty session type systems to use access control based on linear or affine types. While useful in offering strong guarantees of communication safety and session fidelity, linearity and affinity run into the well-known problem of inflexible programming, excluding scenarios that make use of shared channels or need to store channels in shared data structures. In this paper, we develop capability-based resource sharing for multiparty session types. In this setting, channels are split into two entities, the channel itself and the capability of using it. This gives rise to a more flexible session type system, which allows channel references to be shared and stored in persistent data structures. We illustrate our type system through a producer-consumer case study. Finally, we prove that the resulting language satisfies type safety

Scanning Electrochemical Microscopy. Theory of the Feedback Mode

The steady-state current that flows between the scanning tlp (a disk ultramicroelectrode imbedded in an Insulating sheath) and a planar sample substrate in a scannlng electrochemical microscope (SECM) operating in the feedback mode is calculated by the finite element method with an exponentlaily expandlng grld, for both conductlve and Insulating samples. For conductlve substrates the tip current, representing, for example, the oxidatkn reactlon of R to 0, is enhanced by flow of R generated at the substrate to the tlp and is a functlon of tiphubstrate distance, d , but not the radius of the lnsuiatlng sheath. For insulating substrates, the tlp current Is decreased by blockage of the diffusion of R to the tip by the substrate and depends upon d and the Insulating sheath radius. The theoretical results are compared to experimental studies

Compaction and subsidence of the Groningen gas field in the Netherlands

The Groningen gas field in the Netherlands is Europe's largest gas field. It has been produced since 1963 and production is expected to continue until 2080. The pressure decline in the field causes compaction in the reservoir which is observed as subsidence at the surface. Measured subsidence is characterized by a delay at the start of production. As linear compaction models cannot explain this behavior, alternative compaction models (e.g. Rate Type Compaction Model and Time Decay model) have been investigated that may explain the measured subsidence. Although the compaction models considered in this study give a good match to this delay, their forecasts are significantly different. Future measurements of subsidence in this area will indicate which type of compaction model is preferred. This will lead to better forecasts of subsidence in future. The pattern of over- and underestimation of the subsidence is similar for the compaction models investigated and tested. The pattern can be explained by differences in modeled porosity and aquifer activity illustrating the improvement of subsurface knowledge on the reservoir using subsidence measurements

Compaction and subsidence of the Groningen gas field in the Netherlands

The Groningen gas field in the Netherlands is Europe’s largest gas field. It has been produced since 1963 and production is expected to continue until 2080. The pressure decline in the field causes compaction in the reservoir which is observed as subsidence at the surface. Measured subsidence is characterized by a delay at the start of production. As linear compaction models cannot explain this behavior, alternative compaction models (e.g. Rate Type Compaction Model and Time Decay model) have been investigated that may explain the measured subsidence. Although the compaction models considered in this study give a good match to this delay, their forecasts are significantly different. Future measurements of subsidence in this area will indicate which type of compaction model is preferred. This will lead to better forecasts of subsidence in future. The pattern of over- and underestimation of the subsidence is similar for the compaction models investigated and tested. The pattern can be explained by differences in modeled porosity and aquifer activity illustrating the improvement of subsurface knowledge on the reservoir using subsidence measurement

Isotach formulation of the rate type compaction model for sandstone

This paper presents a new formulation of the Rate Type Compaction Model (RTCM) for sandstone based on the isotach concept. The RTCM was originally developed to explain the loading rate dependent compaction behaviour observed in laboratory test on unconsolidated and consolidated sandstone samples and the delayed subsidence behaviour above depleting reservoirs. The original RTCM equation has the limitation of being unable to describe transitions between different loading rates, including the transition to a loading rate of zero (creep). The new formulation combines the features of the original RTCM with the isotach concept developed is soft soil geotechnics, which enables transitions between different loading rates, thereby overcoming the limitations of the original RTCM. The isotach formulation of the RTCM model is used to simulate a multiple loading rate experiment on a Rotliegend sandstonwe core sample. The agreement between results of the lab experiment and the proposed isotach RTCM model is excellen