Tool support for reasoning in display calculi

We present a tool for reasoning in and about propositional sequent calculi. One aim is to support reasoning in calculi that contain a hundred rules or more, so that even relatively small pen and paper derivations become tedious and error prone. As an example, we implement the display calculus D.EAK of dynamic epistemic logic. Second, we provide embeddings of the calculus in the theorem prover Isabelle for formalising proofs about D.EAK. As a case study we show that the solution of the muddy children puzzle is derivable for any number of muddy children. Third, there is a set of meta-tools, that allows us to adapt the tool for a wide variety of user defined calculi

Analyzovanie tesniacých vlastností skrutkového spoja s oceľovým tesnením použitím metódy konečných prvkov

This article deals with study of contact pressure/gap distribution on a bolted joint of a hydrostatic transmission. The study was performed via numerical analyses with support of ANSYS a finite element method software package. The main focus in the results evaluation is aimed on evaluation of the contact pressure/gap on the bolted joint after tightening individual bolts and after applying operational loads on the hydrostatic unit. Operational loads in the analyses were represented by applying of an operational pressure into the individual areas of the unit. The operational pressure was applied in two time steps of the Finite Element Method analysis to simulate normal and reverse mode of the hydrostatic transmission. Numerical results were verified through experimental measurements carried out by using FujiFilm tests.Tento článok sa zaoberá skúmaním rozloženia kontaktného tlaku resp. kontaktnej vôle skrutkového spoja hydrostatického prevodníka. Skúmanie týchto ukazovateľov bolo realizované numerickými analýzami s využitím konečno-prvkového softvéru ANSYS Workbench. Cieľom príspevku je vyhodnotenie kontaktného tlaku/vôle skrutkového spoja po uťahovaní jednotlivých skrutiek a po aplikácii prevádzkového zaťaženia hydrostatickej jednotky. Prevádzkové zaťaženie v analýzach predstavovalo aplikáciu prevádzkového tlaku do jednotlivých oblastí jednotky. Pracovný tlak bol aplikovaný v dvoch časových krokoch konečno- prvkovej analýzy, nakoľko bol simulovaný normálny a reverzný chod hydrostatického prevodníka. Numerické výsledky boli následne porovnané s experimentálnymi meraniami, ktoré boli vykonané pomocou FujiFilm testov

Nominal String Diagrams

We introduce nominal string diagrams as string diagrams internal in the category of nominal sets. This requires us to take nominal sets as a monoidal category, not with the cartesian product, but with the separated product. To this end, we develop the beginnings of a theory of monoidal categories internal in a symmetric monoidal category. As an instance, we obtain a notion of a nominal PROP as a PROP internal in nominal sets. A 2-dimensional calculus of simultaneous substitutions is an application

Neon diffusion kinetics and implications for cosmogenic neon paleothermometry in feldspars

Observations of cosmogenic neon concentrations in feldspars can potentially be used to constrain the surface exposure duration or surface temperature history of geologic samples. The applicability of cosmogenic neon to either application depends on the temperature-dependent diffusivity of neon isotopes. In this work, we investigate the kinetics of neon diffusion in feldspars of different compositions and geologic origins through stepwise degassing experiments on single, proton-irradiated crystals. To understand the potential causes of complex diffusion behavior that is sometimes manifest as nonlinearity in Arrhenius plots, we compare our results to argon stepwise degassing experiments previously conducted on the same feldspars. Many of the feldspars we studied exhibit linear Arrhenius behavior for neon whereas argon degassing from the same feldspars did not. This suggests that nonlinear behavior in argon experiments is an artifact of structural changes during laboratory heating. However, other feldspars that we examined exhibit nonlinear Arrhenius behavior for neon diffusion at temperatures far below any known structural changes, which suggests that some preexisting material property is responsible for the complex behavior. In general, neon diffusion kinetics vary widely across the different feldspars studied, with estimated activation energies (Ea) ranging from 83.3 to 110.7 kJ/mol and apparent pre-exponential factors (D0) spanning three orders of magnitude from 2.4 × 10−3 to 8.9 × 10−1 cm2 s−1. As a consequence of this variability, the ability to reconstruct temperatures or exposure durations from cosmogenic neon abundances will depend on both the specific feldspar and the surface temperature conditions at the geologic site of interest

Enhanced rock-slope failure following ice-sheet deglaciation : timing and causes

This research was supported by NERC Cosmogenic Isotope Analysis Facility [Grant Number: 9046.0308]The temporal pattern of rock-slope failures (RSFs) following Late Pleistocene deglaciation on tectonically stable terrains is controversial: previous studies variously suggest (1) a rapid response due to removal of supporting ice (‘debuttressing’), (2) a progressive decline in RSF frequency, and (3) a millennial-scale delay before peak RSF activity. We test these competing models through beryllium-10 (10Be) exposure dating of five closely-spaced quartzite RSFs on the Isle of Jura, Scotland, to establish the relationship between timing of failure and those of deglaciation, episodes of rapid warming and periods of rapid glacio-isostatic uplift. All five dated RSFs occurred at least 720–2240 years after deglaciation, with the probability of failure peaking ~2 ka after deglaciation, consistent with millennial-scale delay model (3). This excludes debuttressing as an immediate cause of failure, though it is likely that time-dependent stress release due to deglacial unloading resulted in progressive development of failure planes within the rock. Thaw of permafrost ice in joints is unlikely to have been a prime trigger of failure as some RSFs occurred several centuries after the onset of interstadial warming. Conversely, the timespan of the RSFs coincides with the period of maximum glacio-isostatic crustal uplift, suggesting that failure was triggered by uplift-driven seismic events acting on fractured rock masses. Implications of this and related research are: (1) that retreat of the last Pleistocene ice sheets across tectonically-stable mountainous terrains was succeeded by a period of enhanced rock-slope failure due to deglacial unloading and probably uplift-driven seismicity; (2) that the great majority of RSFs in the British Isles outside the limits of Loch Lomond Stadial (= Younger Dryas) glaciation are of Lateglacial (pre-Holocene) age; and (3) numerous RSFs must also have occurred inside Loch Lomond Stadial (LLS) glacial limits, but that runout debris was removed by LLS glaciers.PostprintPeer reviewe

Tri-Nodal Social Entanglements in Iron Age Sicily: Material and Social Transformation

Indigenous Iron Age Sicilian populations underwent a series of complex social transformations following the establishment of neighboring Greek and Phoenician trade posts in the eighth through fifth centuries BC. This paper employs the theory of cultural hybridity to explore indigenous Iron Age Elymian responses to the socially entangled atmosphere. Prolonged contact and interaction with foreigners fostered numerous alterations to Elymian pottery, architecture, and language. Such archaeologically visible changes are discussed, accounting for the development of a complex social middle ground encompassing the Elymi, Greeks, and Phoenicians. Additionally, this paper offers an agenda for future research focusing on the development of mixed-style material culture within complex social entanglements

Material Expressions of Social Change: Indigenous Sicilian Responses to External Influences in the First Millennium B.C.

Following the arrival of Greek colonists and Phoenician traders in the seventh century BC, indigenous Iron Age Sicilian populations underwent an intensive process of social transformation. As a result, many new behaviors, including those associated with Greek-style feasting and commensality, were introduced to indigenous Sicilians, together with the associated material culture. This study explores Iron Age indigenous Sicilian social responses to these interactions, focusing on the feast as a conduit of change and the concomitant transformation of feasting accoutrements. Vessel form, manufacturing technique, and surface treatment impact the emblemic ceramic styles used to communicate ethnic affiliations in the various social middle grounds that developed to mitigate cultural differences. These morphologic variables are compared in order to identify mixed-style vessels resulting from social entanglement. Social as well as economic interpretations of the development of mixed-style pottery are posited. Compositional X-ray fluorescence (XRF), X-ray diffraction (XRD), and ceramic petrography of a sub-sample of pottery vessels from seven sites across the island are used to model and map the production and manufacture of mixed-style feasting vessels. The results of this study suggest that economic as well as social forces led to the development of mixed-style vessels manufactured at multiple population centers in response to interactions with foreign colonists and merchants

Negotiating Social Entanglements through Feasting in Iron Age and Archaic Western Sicily

Iron Age and Archaic western Sicilians interacted with Greek and Phoenician colonists. The effects of this interaction accumulated over time, introducing new ideas and material culture. Here, western Sicilians transformed their feasting assemblages, reinventing their visual displays of wealth, power, and prestige. This local response created new material culture and expressions of identity.I Siciliani occidentali dell’età del ferro e arcaici interagirono con i coloni greci e fenici. Gli effetti di questa interazione si sono accumulati nel tempo, introducendo nuove idee e cultura materiale. Qui, i Siciliani occidentali hanno trasformato i loro festeggiamenti, reinventando le loro manifestazioni visive di ricchezza, potere e prestigio. Questa risposta locale ha creato una nuova cultura materiale ed espressioni di identità

Middle pleistocene glaciation in Patagonia dated by cosmogenic-nuclide measurements on outwash gravels

The well-preserved glacial record in Argentine Patagonia offers a ~ 1 Ma archive of terrestrial climate extremes in southern South America. These glacial deposits remain largely undated beyond the range of radiocarbon dating at ca. 40 ka. Dating old glacial deposits (> several 105 a) by cosmogenic surface exposure methods is problematic because of the uncertainty in moraine degradation and boulder erosion rates. Here, we show that cobbles on outwash terraces can reliably date ‘old’ glacial deposits in the Lago Pueyrredón valley, 47.5° S, Argentina. Favorable environmental conditions (e.g., aridity and strong winds) have enabled continuous surface exposure of cobbles and preservation of outwash terraces. The data demonstrate that nuclide inheritance is negligible and we therefore use the oldest surface cobbles to date the deposit. 10Be concentrations in outwash cobbles reveal a major glacial advance at ca. 260 ka, concurrent with Marine Isotope Stage 8 (MIS 8) and dust peaks in Antarctic ice cores. A 10Be concentration depth-profile in the outwash terrace supports the age and suggests a low terrace erosion rate of ca. 0.5 mm ka− 1. We compare these data to exposure ages obtained from associated moraines and find that surface boulders underestimate the age of the glaciation by ~ 100 ka; thus the oldest boulders in this area do not date closely moraine deposition. The 10Be concentration in moraine cobbles help to constrain moraine degradation rates. These data together with constraints from measured 26Al/10Be ratios suggest that all moraine boulders were likely exhumed after original deposition. We determine the local Last Glacial Maximum (LGM) occurred at ~ 27–25 ka, consistent with the maximum LGM in other parts of Patagonia

Neolithic Cultural Hybridity: Social Entanglements and the Development of Hybrid Culture in the Western Mediterranean

With the advent and spread of food production technology, Mediterranean populations altered their lifeways, individually adapting to local environments in order to best accommodate the cultigens they would come to rely upon. The subsequent changes in subsistence patterns, domestic architecture, and economic systems characterize the archaeologically recognized transition from Mesolithic to Neolithic culture among indigenous populations. Various explanations accounting for the dispersal and adoption of food production technologies have been posited, including demic diffusion. The purpose of this paper is not to support or negate the demic diffusion model accounting for the spread of agriculture technology, but rather to examine Sicilian and Southern Italian Mesolithic and Neolithic culture via postcolonial theoretical models. Variation in domestic architecture, the adoption of domesticates and the shift to pastoralism all provide evidence supporting the development of Neolithic hybrid cultural entanglements based on elements of Mesolithic lifeways