Search results for "Planetary Science"

The effect of elastic strain on the microstructure of free surfaces of stressed minerals in contact with an aqueous solution

2001

The influence of gradients in bulk elastic strain energy on the dissolution and growth behaviour of minerals in rocks is commonly considered negligible. We experimentally observed, however, that regular arrays of macroscopically visible etch grooves may develop on the originally smooth free surfaces of soluble crystals held in an undersaturated aqueous solution if the crystals are only elastically stressed. These grooves are oriented perpendicular to the compressive stress. They disappear soon after the stress is taken off. The formation of the grooves is well explained by recent theories on the instability of the surface of stressed solids. Development of such instabilities could significa…

Shear strength of a compacted scaly clay in variable saturation conditions

2015

Scaly clays are stiff and highly fissured clays often used as construction materials. This paper presents the results of triaxial compression tests carried out on saturated and unsaturated samples of a compacted scaly clay. Complementary investigation on the microstructural features and their evolution with the amount of water stored into the material are also presented in order to shed light on the evolution of the micro- and macroporosity with suction. The water retention behaviour of the compacted scaly clay is also addressed. The results from the controlled suction triaxial tests are used to discuss the applicability of a single-shear strength criterion to compacted double-structured cl…

Spatio-temporal changes in degassing behavior at Stromboli volcano derived from two co-exposed SO2 camera stations

2022

Improving volcanic gas monitoring techniques is central to better understanding open-vent, persistently degassing volcanoes. SO2 cameras are increasingly used in volcanic gas studies, but observations are commonly limited to one single camera alone viewing the volcanic plume from a specific viewing direction. Here, we report on high frequency (0.5 Hz) systematic measurements of the SO2 flux at Stromboli, covering a 1-year long observation period (June 2017-June 2018), obtained from two permanent SO2 cameras using the same automated algorithm, but imaging the plume from two different viewing directions. Our aim is to experimentally validate the robustness of automatic SO2 camera for volcano …

Helium–strontium isotope constraints on mantle evolution beneath the Roman Comagmatic Province, Italy

2004

- European Social Fund - Scottish Universities - Carnegie Trust for the Universities of Scotland.

Strontium and argon isotopic homogenization of pelitic sediments during low-grade regional metamorphism: The pan-African upper Damara sequence of Nor…

1979

Abstract The fine mineral fractions extracted from pelitic sediments of the Eocambrian upper Damaran Mulden Group were subjected to a detailed isotopic study by the Rb-Sr and K-Ar methods in combination with a mineralogical analysis by X-ray diffractometry. The sediments contain two major parageneses of metamorphic origin which can be related to two separate low-grade regional metamorphic events of anchizonal intensity with temperatures between 250 and 300°C and pressures up to 2 kbar. These events are dated at about 535 m.y. and 455 m.y. respectively (with λ( 87 Rb) = 1.42 × 10 −11 yr −1 ). Anomalously high K-Ar ages on samples from specific stratigraphic horizons can be related to open sy…

CyProF – Insights from a Framework for Designing Cyber-Physical Systems in Production Environments

2016

Abstract There is little experience in integrating cyber-physical systems (CPS) in production environments nowadays. A coordinated framework with reference architecture, methodology and procedural model can support the adaption of CPS by providing a pre-defined structure and guidelines. This paper describes such a framework, named CyProF, for designing CPS-based solutions in production environments. Engineers are supported by this framework in handling the complexity during the design phase. Additionally, this paper explains how the framework was used in a use case to reduce engineering efforts for a CPS-based demonstrator.

Selecting industrial robots for milling applications using AHP

2017

Abstract Industrial robots are usually used for pick-and-place applications, which require only point-to-point motion control. However, the recent developments, both in robot technology and in Computer Automated Machining (CAM) software, allow the use of these equipment in applications which require continuous path control, such as multi-axis milling processes. However, the producers do not offer robots specifically developed for this kind of application, thus the user has to choose the most appropriate robot for this goal from a wide range of general purpose robot types. This research work proposes a method based upon Analytic Hierarchy Process (AHP) for selecting the industrial robot for …

Recent advances in space-time statistics with applications to environmental data: An overview

2003

[1] This paper introduces a special section based on general environmental scientific problems, with a particular focus on using atmospheric data. All the papers and authors provide the methodology to study, analyze, predict, and evaluate the spatial-temporal behavior and the complicated spatial-temporal structure of the data. The overall aim is to present up-to-date developments in spatial and spatiotemporal statistics in the field of the atmosphere, to present on-going research, and to discuss important problems to be addressed in the near future.

The TriMCo corpus of Slavic and Baltic dialects: structure, goals and case studies

2019

Structure finding in cosmological simulations: the state of affairs

2013

The ever increasing size and complexity of data coming from simulations of cosmic structure formation demands equally sophisticated tools for their analysis. During the past decade, the art of object finding in these simulations has hence developed into an important discipline itself. A multitude of codes based upon a huge variety of methods and techniques have been spawned yet the question remained as to whether or not they will provide the same (physical) information about the structures of interest. Here we summarize and extent previous work of the "halo finder comparison project": we investigate in detail the (possible) origin of any deviations across finders. To this extent we decipher…