The EURADOS CR-39 Quality task for the optimisation and harmonisation of personal neutron dosimetry with CR-39 (PADC).

CR-39 (PADC) nuclear track detectors are among the most widespread devices used for personal neutron dosimetry; however, some issues related to the variable material quality of the CR-39 polymer hinder the performance of CR-39-based dosemeters. For this reason, the Working Group 2 (WG2) of the European Radiation Dosimetry Group (EURADOS) has recently launched the CR-39 Quality task, a project aimed at improving and harmonising personal neutron dosimetry with CR-39 in Europe. Whitin this task, a close collaboration among researchers, individual monitoring services and dosemeter grade CR-39 manufacturers is achieved, thus facilitating the direct dialog between producer and consumer to reach an optimised material for personal neutron dosimetry applications.

Measurements in pulsed neutron fields.

Dosimetry in pulsed and mixed radiation fields represents an important challenge in radiation measurements, because in several accelerator technologies, the acceleration occurs in bunches of particles with short time duration, producing intense radiation pulses spaced by a relatively long time of beam off. The stray mixed radiation field generated around these installations maintains the same time structure as the primary beam and causes a problem in workplace fields' monitoring. Active neutron detectors normally used in steady neutron fields, specifically REM-counters and Bonner sphere spectrometers, can suffer pulsed fields because of the high dead time losses during the bursts and are often inadequate for pulsed field monitoring. This work reviews the efforts of European Radiation Dosimetry Group (EURADOS), and in particular of the Working Group 11 'High Energy Radiation Fields', to define the problem, characterize instrumentation and to propose solutions to the issue of pulsed and mixed radiation fields. Despite the EURADOS initiative, several open issues still remain. A metrological traceability for pulsed neutron fields is missing. There is still room for the optimization and better characterization of available instruments. Initiatives of education and training are required.

Digital twins for land-based aquaculture: A case study for rainbow trout ( Oncorhynchus mykiss).

The virtual, digital counterpart of a physical object, referred as digital twin, derives from the Internet of Things (IoT), and involves real-time acquisition and processing of large data sets. A fully implemented system ultimately enables real-time and remote management, as well as the reproduction of real and forecasted scenarios. Under the emerging framework of Precision Fish Farming, which brings control-engineering principles to fish production, we set up digital twin prototypes for land-based finfish farms. The digital twin is aimed at supporting producers in optimizing feeding practices, oxygen supply and fish population management with respect to 1) fish growth performances; 2) fish welfare, and 3) environmental loads. It relies on integrated mathematical models which are fed with data from in-situ sensors and from external sources, and simulate several dynamic processes, allowing the estimation of key parameters describing the ambient environment and the fishes. A conceptual application targeted at rearing cycles of rainbow trout ( Oncorhynchus mykiss) in an operational in-land aquafarm in Italy is presented. The digital twin takes into account the disparate levels of automation and control that are found within this farm, and considerations are made on preferential directions for future developments. In spite of its potential, and not only in the aquaculture sector, the development of digital twins is still at its early stage. Furthermore, Precision Fish Farming applications in land-based systems as well as targeted at rainbow trout are novel developments.

A digital twin is set up for a rainbow trout ( Oncorhynchus mykiss) aquaculture farm located in northern Italy. The farm is equipped with large-scale basins, and are supplied by freshwater from the neighbouring Sarca river. Generally speaking, digital twins are virtual, digital representations which mirror and are connected to real objects, enabling real-time and remote management, as well as the reproduction of real or forecasted scenarios. This is a pioneer application aimed at supporting producers in optimizing feeding practices, oxygen supply and fish population management with respect to 1) fish growth performances; 2) fish welfare, and 3) environmental loads. The digital twin relies on sensors, Big Data, IoT (Internet of Things) and predictive mathematical models. In spite of its potential, and not only in the aquaculture sector, the development of digital twins is still at its early stage. Furthermore, Precision Fish Farming applications in land-based systems as well as targeted at rainbow trout are novel developments.