Development of groundwater radon continuous monitors: Comparison between α scintillation and γ spectrometry systems

Two temporised continuous monitoring systems, designed to measure the radon concentration in natural environments, mainly groundwater, were assembled, tested and cross-check compared, evaluating the background noise, sensitivity, calibration values and soundest application in the Earth Science framework. The two systems have been customised by DINCE Laboratory, based on best-fitting criteria selected according to the ING laboratory, partially in the frame of two EC funded, Geochemical Seismic Zonation (GSZ) and Automatic Geochemical Monitoring of Volcanoes, addressed to earthquake prediction research and prototype developing, aimed to seismic and volcanic risks surveillance. Following best-fitting criteria of the radon monitoring aimed to natural risk research, both systems are operative by discrete temporised sampling of an aliquot of groundwater, with a minimal interval of six hours. During their functioning at the ENEA Centre of Frascati (Rome), the test-site chosen, both systems provided a continuous and reliable response

Nest guarding behaviour of a temperate wrasse differs between sites off Mediterranean CO2 seeps

Organisms may respond to changing environmental conditions by adjusting their behaviour (i.e., behavioural plasticity). Ocean acidification (OA), resulting from anthropogenic emissions of carbon dioxide (CO2), is predicted to impair sensory function and behaviour of fish. However, reproductive behaviours, and parental care in particular, and their role in mediating responses to OA are presently overlooked. Here, we assessed whether the nesting male ocellated wrasse Symphodus ocellatus from sites with different CO2 concentrations showed different behaviours during their breeding season. We also investigated potential re-allocation of the time-budget towards different behavioural activities between sites. We measured the time period that the nesting male spent carrying out parental care, mating and exploring activities, as well as changes in the time allocation between sites at ambient (~400 μatm) and high CO2 concentrations (~1000 μatm). Whilst the behavioural connectance (i.e., the number of linkages among different behaviours relative to the total amount of linkages) was unaffected, we observed a significant reduction in the time spent on parental care behaviour, and a significant decrease in the guarding activity of fish at the high CO2 sites, with a proportional re-allocation of the time budget in favour of courting and wandering around, which however did not change between sites. This study shows behavioural differences in wild fish living off volcanic CO2 seeps that could be linked to different OA levels, suggesting that behavioural plasticity may potentially act as a mechanism for buffering the effects of ongoing environmental change. A reallocation of the time budget between key behaviours may play a fundamental role in determining which marine organisms are thriving under projected OA

Lumped parameters multi-fidelity digital twins for prognostics of electromechanical actuators

The growing affirmation of on-board systems based on all-electric secondary power sources is causing a progressive diffusion of electromechanical actuators (EMA) in aerospace applications. As a result, novel prognostic and diagnostic approaches are becoming a critical tool for detecting fault propagation early, preventing EMA performance deterioration, and ensuring acceptable levels of safety and reliability of the system. These approaches often require the development of various types of multiple numerical models capable of simulating the performance of the EMA with different levels of fidelity. In previous publications, the authors already proposed a high-fidelity multi-domain numerical model (HF), capable of accounting for a wide range of physical phenomena and progressive failures in the EMA, and a low-fidelity digital twin (LF). The LF is directly derived from the HF one by reducing the system degrees of freedom, simplifying the EMA control logic, eliminating the static inverter model and the three-phase commutation logic. In this work, the authors propose a new EMA digital twin, called Enhanced Low Fidelity (ELF), that, while still belonging to the simplified types, has particular characteristics that place it at an intermediate level of detail and accuracy between the HF and LF models. While maintaining a low computational cost, the ELF model keeps the original architecture of the three-phase motor and the multidomain approach typical of HF. The comparison of the preliminary results shows a satisfactory consistency between the experimental equipment and the numerical models

Reward and punishment enhance motor adaptation in stroke

Background and objective: The effects of motor learning, such as motor adaptation, in stroke rehabilitation are often transient, thus mandating approaches that enhance the amount of learning and retention. Previously, we showed in young individuals that reward and punishment feedback have dissociable effects on motor adaptation, with punishment improving adaptation and reward enhancing retention. If these findings were able to generalise to patients with stroke, they would provide a way to optimise motor learning in these patients. Therefore, we tested this in 45 patients with chronic stroke allocated in three groups. / Methods: Patients performed reaching movements with their paretic arm with a robotic manipulandum. After training (day 1), day 2 involved adaptation to a novel force field. During the adaptation phase, patients received performance-based feedback according to the group they were allocated: reward, punishment or no feedback (neutral). On day 3, patients readapted to the force field but all groups now received neutral feedback. / Results: All patients adapted, with reward and punishment groups displaying greater adaptation and readaptation than the neutral group, irrespective of demographic, cognitive or functional differences. Remarkably, the reward and punishment groups adapted to similar degree as healthy controls. Finally, the reward group showed greater retention. / Conclusions: This study provides, for the first time, evidence that reward and punishment can enhance motor adaptation in patients with stroke. Further research on reinforcement-based motor learning regimes is warranted to translate these promising results into clinical practice and improve motor rehabilitation outcomes in patients with stroke

Multiple interannual records of young-of-the-year identify an important area for the protection of the shortfin mako, Isurus oxyrinchus

The shortfin mako (Isurus oxyrinchus) is the second most fishery-exploited pelagic shark in the Mediterranean Sea, thus its conservation status is a cause for concern. Despite the species has been listed in fishery and trade regulations to hinder its population decline, the lack of knowledge on its distribution patterns and habitats essential for its persistence still hampers the implementation of sound conservation actions. Combining data from local expert knowledge, opportunistic catch records, and Baited Remote Underwater Videos, we show evidence of the interannual presence of young-of-the-year (YOY) I. oxyrinchus in the Pelagie Archipelago (Central Mediterranean Sea). A total of twenty-one individuals ranging 71–92.5 cm FL were incidentally caught (on average 2.3 YOY/1000 hooks) or documented on BRUVS in July and August over three consecutive years. These data coupled with questionnaires administered to longline fishers identify one specific area used by YOY in the summer months. Our study presents the most abundant record of YOY shortfin makos in the Mediterranean Sea within such a restricted time and limited area providing important information for improving the protection of this critically endangered species

Diagnostics of electro-mechanical actuators based upon the back-EMF reconstruction

Electrical systems are gradually replacing the more traditional hydraulic and pneumatic solutions for the transmission of secondary energy for onboard aircraft equipment. Therefore fault detection and health management strategies properly conceived for electrical devices are becoming a highly relevant topic for research and development in the aerospace disciplines. One possible practical implementation of these methodologies would be the identification of parameters for diagnostic and prognostic monitoring, which are highly sensitive to incipient faults but, at the same time, are less influenced by operating conditions (external loads, command input, temperatures, etc.). In this paper, the authors evaluated the effectiveness of counter-electromotive force (back-EMF) coefficient as a prognostic parameter, emphasizing a novel sampling approach that significantly lower the computational effort required while maintaining a good back-EMF coefficient curve reconstruction. The approach is virtual sensor-like, using only already available data for the correct operation of the BLDC motor. The proposed method was tested by evaluating the back-EMF coefficient reconstruction as a function of some progressive failures typical of EMA motors, such as inter-turn partial shorts and rotor static eccentricity. Its robustness to external disturbances has been tested by evaluating different actuation commands and operating conditions. As expected, the back-EMF signal shows a marked dependence on the considered failure modes and, at the same time, a suitable insensitivity to the other external factors

Design and development of innovative FBG-based fiber optic sensors for aerospace applications

In recent years aeronautical systems are becoming increasingly complex, as they are often required to perform various functions. New intelligent systems are required capable of self-monitoring their operation parameters, able to estimate their health status, and possibly perform diagnostic or prognostic functions. For these purposes, these systems frequently need to acquire several different signal types; although it is sometimes possible to implement virtual sensor techniques, it is usually necessary to implement dedicated sensing hardware. On the other hand, the installation of the required sensors can, however, significantly increase the complexity, the weight, the costs and the failure rate of the entire system. To overcome these drawbacks, new types of optical sensors, minimally invasive for measuring the system parameters and having a high spatial resolution and a minimum added complexity are now available. Fiber Bragg Gratings (FBGs) sensors are suitable for measuring various technical parameters in static and dynamic mode and meet all these requirements. In aerospace, they can replace several traditional sensors, both in structural monitoring and in other system applications, including mechatronic systems diagnostics and prognostics. This work reports the results of our experimental research aimed at evaluating and validating different FBG installation solutions such as deformation, bending, vibration, and temperature sensors. These were compared with numerical simulations results and measurements performed with traditional strain gauges and accelerometers

Preliminary Analysis on Environmental and Intrinsic Factors on FBG-Based Vibration Sensors

In recent years, optical-based sensors have sparked interest for the many advantages over traditional, electrical-based sensors, such as EMI insensitivity, ease of multiplexing on a single line, resilience to hostile environment and very compact size and global weight saving due to signal cables reduction. Considering said properties, optical sensors offer a compelling alternative to traditional sensing elements. One type of optical sensor is the Fiber Braggs Gratings sensors (FBG), which is a type of sensor that reflects a very narrow band of wavelengths, called Bragg wavelength, while being transparent for others; this behavior is achieved by local variations of the core refractive index. The Bragg wavelength can be easily correlated with physical changes in the sensor itself, due to either physical strain or temperature variation. It should be noted that the achievable measurement accuracy is thus comparable to the Bragg wavelength. However, for any practical application, FBGs need to be bonded to a support or surface; in this case, there is a lack of understanding of the effects of temperature and humidity variations on the combined sensor-glue system. In this work, a setup, intended to characterize the sensitivity of the fiber-glue combination to humidity and temperature will be presented

Innovative actuator fault identification based on back electromotive force reconstruction

The ever increasing adoption of electrical power as secondary form of on-board power is leading to an increase in the usage of electromechanical actuators (EMAs). Thus, in order to maintain an acceptable level of safety and reliability, innovative prognostics and diagnostics methodologies are needed to prevent performance degradation and/or faults propagation. Furthermore, the use of effective prognostics methodologies carries several benefits, including improved maintenance schedule capability and relative cost decrease, better knowledge of systems health status and performance estimation. In this work, a novel, real-time approach to EMAs prognostics is proposed. The reconstructed back electromotive force (back-EMF), determined using a virtual sensor approach, is sampled and then used to train an artificial neural network (ANN) in order to evaluate the current system status and to detect possible coils partial shorts and rotor imbalances

Autonomy in students attending last year of high schools: A study about guidance activities performed

The ending of high school raises, in students of last year, questions about what to do once they finished school. The wide variety of possible paths to choose, places youth at a crossroads that inevitably involves making decisions about the future. Vocational guidance can accompany young people and help them to identify what path to start and to consider the reasons for their choice. In this sense, guidance is currently conceived as a process that contributes to build a life project, setting goals, planning and developing strategies for it. One of the objectives of Psychology of Orientation, at present, is favor the construction of life, educational and job projects, being one of the objectives, the group approach (Aisenson, 2007). Year after year, the Direccion Técnica Programa Orientación al Estudiante (DOE) – Subsecretaria de Coordinación Académica, Secretaría de Asuntos Académicos, Universidad de Buenos Aires - develops orientation groups destined to students of the last year of high school, that come from public or private educational establishments in the Autonomous City of Buenos Aires, the outskirts of the city and other places all over Argentina, who approach the DOE in a personal and spontaneous manner demanding vocational guidance. Our objectives are describe sociodemographic profile of young people consultants of vocational guidance group developed in DOE, present activities of vocational guidance done before their participation in the groups from the perspective of adolescent autonomy and analyse group device appraisal in the setting up of study and work project.Facultad de Psicologí