Increased fluid flow activity in shallow sediments at the 3 km Long Hugin Fracture in the central North Sea

The North Sea hosts a wide variety of seafloor seeps that may be important for transfer of chemical species, such as methane, from the Earth's interior to its exterior. Here we provide geochemical and geophysical evidence for fluid flow within shallow sediments at the recently discovered, 3-km long Hugin Fracture in the Central North Sea. Although venting of gas bubbles was not observed, concentrations of dissolved methane were significantly elevated (up to six-times background values) in the water column at various locations above the fracture, and microbial mats that form in the presence of methane were observed at the seafloor. Seismic amplitude anomalies revealed a bright spot at a fault bend that may be the source of the water column methane. Sediment porewaters recovered in close proximity to the Hugin Fracture indicate the presence of fluids from two different shallow (<500m) sources: (i) a reduced fluid characterized by elevated methane concentrations and/or high levels of dissolved sulfide (up to 6 mmol L−1), and (ii) a low-chlorinity fluid (Cl ∼305 mmol L−1) that has low levels of dissolved methane and/or sulfide. The area of the seafloor affected by the presence of methane-enriched fluids is similar to the footprint of seepage from other morphological features in the North Sea

Changing educational roles and competences during the COVID crisis. A case study from Turin, Italy

Adopting the point of view of teachers and educators, authors explore how educational relationships with immigrant students changed and how these changes have impacted their cognitive and emotional skills in a specific Italian context. Arguments are built on the data collected in micro case studies carried out in spring 2020 in formal and non-formal educational contexts in Northern Italy

Monitoring Subsurface CO

An overview is given of various currently applied monitoring techniques for CO2 storage. Techniques are subdivided in correspondence to their applicability for monitoring three distinct realms. These are: - the atmosphere and the near- surface; - the overburden (including faults and wells); - the reservoir with its seals. Another subdivision can be made with respect to time, i.e. first monitoring during the injection and storage process and subsequently monitoring for the long term (after abandonment of the field). In this perspective, the importance of characterisation and monitoring before injection is addressed

The data acquisition system (DAS) for the improved CERN SC

A digital data acquisition system (DAS) based on a minicomputer is described which registers the failure sequences in various equipment areas of the CERN synchrocyclotron (henceforward referred to as the SC). The avalanches of failure signals which occur from time to time are tapped from the alarm/security systems, time-resolved to 10 msec and recorded on a printer in order to aid SC failure diagnosis. The mechanisms of the DAS and its relation to the SC equipment are explained in some detail. All programs were constructed at assembler language level for speed and for ease of on-line program maintenance. The alarm sequences recorded have been of considerable help during the running in of the new radiofrequency system. Now that the new SC is operational, the DAS furnishes useful data from several equipment areas to the operators and engineers

Performance of retrofitted steel structures subjected to fatigue loading

Steel structures today are edging towards the end of their design life, as the frequency and magnitude of loadings are becoming significantly greater in comparison to the initial design loads at the time of construction. Deterioration from prolonged exposure to environmental conditions including weathering and climate change, as well as the effects of human error, also influence the design life of these older steel structures. This paper will focus on developing a comparison between the fatigue performance of old and new steel structures. The fatigue resistance of both the old and new steel structures is evaluated by investigating and analysing the stresses at critical locations within the structures. Retrofitting techniques are applied to both the old and new structures and analysed in terms of their capacity to increase resistance to fatigue failure and extend the design life of steel structure. The research herein consists of both experimental studies and numerical analysis. Fatigue induced cracking is introduced into the FE model to investigate the post-damage performance of the old and new structures. Retrofitting methods are introduced into the FE model to investigate improvements in the fatigue performance of the old and new girders. An overall conclusion determines the extent of increasing design life, enhancing profitable engineering and focus on sustainability in terms retrofitting an old structure