Abstract
Almost two years have passed since COVID-19 was officially declared a pandemic by the World Health Organization. However, it still holds a tight grasp on the entire human population. Several variants of concern, one after another, have spread throughout the world. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron variant may become the fastest spreading virus in history. Therefore, it is more than evident that the use of personal protective equipment (PPE) will continue to play a pivotal role during the current pandemic. This work depicts an integrative approach attesting to the effectiveness of ultra-violet-C (UV-C) energy density for the sterilization of personal protective equipment, in particular FFP2 respirators used by the health care staff in intensive care units. It is increasingly clear that this approach should not be limited to health care units. Due to the record-breaking spreading rates of SARS-CoV-2, it is apparent that the use of PPE, in particular masks and respirators, will remain a critical tool to mitigate future pandemics. Therefore, similar UV-C disinfecting rooms should be considered for use within institutions and companies and even incorporated within household devices to avoid PPE shortages and, most importantly, to reduce environmental burdens.

Abstract
Over the years, many techniques have been developed for the stabilisation of bone fractures. The study of the adhesion of bone-to-bone cement is an important step towards the development of new immobilization systems. Although bone cement has been used for more than fifty years, very few studies have been performed regarding the evaluation of fracture properties. In this work, numerical and experimental investigations were conducted to evaluate the strain energy release rate under mode I loading in a bone-cement bonded joint, using the Double Cantilever Beam (DCB) test. Cohesive zone laws were also measured combining the finite element method with non-linear elastic fracture mechanics. This has been made in a cortical bone bonded joint with polymethylmethacrylate (PMMA). Consistent results have been obtained regarding fracture toughness in a widely used bone-to-bone cement joint in many biomedical applications.

Abstract
The seashore is the front door to the oceans and the sustain of many societies. However, humans still seem to be unable to unlock new paradigms to project sustainable growth of marine and coastal ecosystems. One of the reasons for this is the lack of knowledge about the natural processes that systematically change their balance. Thus, a new generation of tools is needed to gather data to validate and predict geostatistical models and protect this important resource. This manuscript reports the design and validation of a multi-parameter marine station installed in the estuary of Cavado - Portugal. For the last two years, the station has hosted several own-developed sensors to monitor water parameters, and it was designed to send the monitoring data, in real-time, to a public website so the information can be shared with the communities. So far, the monitoring station has been able to produce data about hydraulic and environmental dynamics, such as water column height or sediment displacement, as well as seasonal events and other extreme phenomena occurrences such as floods. The proposed monitoring system, built in a low-power and low-cost philosophy, aims to allow massive replication all over the coastal areas and to deliver qualitative and quantitative data for better management and planning of the littoral.

Abstract
<p>The management of natural hazards is a vital concern for the sustainable development of any country and information is the single most important factor to tackle the risks from natural hazards within the risk reduction phase, and to manage response during a crisis. To cope with these challenges it is required, on one hand, to collect baseline information on the natural systems to understand their current state, to identify changes and predict or forecast their future behaviour and, on the other hand, to update information during crisis to review and determine management strategies.</p><p>One major difficulty to this approach is the economic weight of the classic monitoring systems, requiring heavy investments, costly maintenance, and substantial human resources. To overcome these obstacles, an alternative concept was developed based on low-cost and fast deployable wireless sensors networks made by autonomous devices, each capable to communicate to a cloud computing service that compiles and processes data, producing information readily accessible via web.</p><p>The 2021 eruption of the Cumbre Vieja volcano presented an excellent opportunity for a proof of concept of this idea. A trial run was set up on this challenging environment, focusing mainly on the detection and measurement of eruptive products, targeting the measurement of eruptive plume components, such as carbon dioxide (CO<sub>2</sub>), sulphur dioxide (SO<sub>2</sub>) and ash (particle matter, PM), and the monitoring of lava flows entering the sea. Besides the sensor’s setups, also the automatic data processing and different communications were tested.</p><p>The experiment consisted of a proximal network of different stations measuring CO<sub>2</sub>, SO<sub>2</sub>, PM<sub>10</sub>, PM<sub>2.5</sub>, temperature, and humidity; a set of trials to intercept the eruptive plume with weather balloons to measure in-situ the same parameters; a distal aethalometer to detect particles from the distal plume; and a set of buoys to monitor hydroacoustic and environmental parameters in the proximity of the lava deltas. The proximal network allowed for a continuous monitoring with information immediately available via web, with good spatial and temporal correlations between different parameters. The atmospheric soundings allowed to measure particle mass concentrations and sulphur dioxide along a profile of the eruptive plume and characterize its vertical profile, with in situ measurements, while back trajectory of air parcel analyses and aethalometer measurements carried out at Izaña Atmospheric Observatory (2367 m.a.s.l.) showed attenuation variability that could be associated with small volcanic particles transported to at least 140 km from the source. The buoys trial allowed to record the acoustic environment near the lava deltas and to test the design and configurations of the device regarding sensors integration and communications.</p><p>The Cumbre Vieja eruption experiment allowed to try-out a fast deployment low-cost multi-sensor system with good results on volcanic plume characterization and real-time data production that proved to be useful for managing volcanic crisis and demonstrated the relevance of this alternative monitoring concept.</p>

Abstract
<p>Volcanic gases and particulate matter (PM) can be hazardous for population not only during an eruptive event, but also during the post-eruption phase, even at significant distances from the volcanic edifice. Volcanic plume dispersion can be affected by diverse factors, such as the weather conditions (<em>e.g</em>., wind speed and direction, rainfall) and/or the topography. Several studies have showed that gas concentrations and PM impacts on the quotidian life during a volcanic crisis can be significant, highlighting the importance of setting up permanent monitoring systems.</p><p>Instruments with carbon dioxide (CO<sub>2</sub>), sulphur dioxide (SO<sub>2</sub>)<sub></sub>and particulate matter (PM<sub>2.5</sub> and PM<sub>10</sub>) low-cost sensors were developed in order to easily and continuously monitor any volcanic area, and the 2021 Cumbre Vieja eruption was chosen as test site to deploy and validate the instrumentation. A network of nine instruments was set up around the volcanic eruption site, covering both the north and south areas of the lava flows, at distances varying between 1.6 and 7 km from the volcano craters. Five instruments were designed to work autonomously in the field, powered by batteries, and the electrical network powered the other four sensors. All nine instruments broadcasted the recorded data via LoRa communication.</p><p>The network settled after the 9<sup>th</sup> December 2021, closer to the ending of the eruptive period, recorded maximum CO<sub>2</sub> concentrations of 1585 ppm at station named “Perm-2”, located at about 4.8 km distance from the volcanic craters, on the 21<sup>st</sup> December 2021. Regarding particulate matter, even if the 24 hour-mean standards set by the World Health Organization (WHO) for the PM<sub>2.5</sub> and PM<sub>10</sub> (25 mg/m<sup>3</sup> and 50 mg/m<sup>3</sup>, respectively) were not exceeded during the monitored period, maximum concentrations were also recorded for these two parameters (470 and 874 mg/m<sup>3</sup>) at “Perm-2” in the 21<sup>st</sup> December. For the same period, the station located closer to the volcano craters measured maximum SO<sub>2</sub> concentrations of 1.11 ppm. Maximum PM values were recorded also at other two monitoring sites in the same day, suggesting spatial and temporal correlation between the different parameters. In this particular case, and considering that maximum concentrations were registered during the night in the exclusion zone, one can reject the potential association of the measured values with suspended ashes resulting from sweeping and cleaning activities. For other periods, particularly after the ending of the eruption, this association must be considered. The highest concentrations of particles post-eruption were measured in the 31<sup>st</sup> December 2021 and 3<sup>rd</sup> January 2022.</p><p>The installed instruments seem to be adequate for an easier and faster deploy during a volcanic crises, allowing recognizing the presence of hazardous gas and particulate matter concentrations, crucial to reduce potential health effects on the population, even after the end of the eruptive phase.</p>

Abstract
Autonomous Underwater Vehicles (AUVs) are seen as a safe and cost-effective platforms for performing a myriad of underwater missions. These vehicles are equipped with multiple sensors which, combined with their long endurance, can produce large amounts of data, especially when used for video capturing. These data need to be transferred to the surface to be processed and analyzed. When considering deep sea operations, where surfacing before the end of the mission may be unpractical, the communication is limited to low bitrate acoustic communications, which make unfeasible the timely transmission of large amounts of data unfeasible. The usage of AUVs as data mules is an alternative communications solution. Data mules can be used to establish a broadband data link by combining short-range, high bitrate communications (e.g., RF and wireless optical) with a Delay Tolerant Network approach. This paper presents an enhanced version of UDMSim, a novel simulation platform for data muling communications. UDMSim is built upon a new realistic AUV Motion and Localization (AML) simulator and Network Simulator 3 (ns-3). It can simulate the position of the data mules, including localization errors, realistic position control adjustments, the received signal, the realistic throughput adjustments, and connection losses due to the fast SNR change observed underwater. The enhanced version includes a more realistic AML simulator and the antenna radiation patterns to help evaluating the design and relative placement of underwater antennas. The results obtained using UDMSim show a good match with the experimental results achieved using an underwater testbed. UDMSim is made available to the community to support easy and faster evaluation of underwater data muling oriented communications solutions and to enable offline replication of real world experiments.