Abstract
In recent years, with the rise of a growing economic and technological interest in lithium mineral resources, there has been a parallel concern, on the part of some local populations and even national environmental groups, for a hypothetical contamination problem that this type of exploitations may cause on the quality of groundwater. Thus, the present study was based on an evaluation of an open-pit quarry, in the so-called Alijó quarry, located in the North of Portugal, in the parish of Canedo, Ribeira de Pena municipality and Vila Real district. This exploitation, under concession by the company José Aldeia Lagoa & Filhos, SA, has been going on for at least 11 years and mainly supplies the ceramic and glass industry. It is in this context that this work is carried out. The general objectives are to assess signs of impacts that extractive activities, carried out in the open-pit exploitation area of Alijó, may have caused on the surrounding subsoil. In this sense, it was necessary to consider the aforementioned hypothesis of the existence of possible sources of water drainage with ionic anomalies for the surrounding environment. If this hypothesis were confirmed, then the level of underground conductivity would have to be proportionally high and obtainable through equivalent low values of electrical resistivity (high electrical conductivity). The current study was limited to geophysical tools along with a few chemical analysis of water samples collected in the open-pit exploration for control purposes. The signs we sought for could possibly be manifested in the form of anomalous concentrations of some of the elements of the mineralization of this lithiniferous pegmatite and whose effects could, hypothetically, be measured in the form of anomalous low values of underground electrical resistivity, as well as anomalous pH valuespresent in the drainage water. To this end, a study mainly supported by the electrical resistivity method was carried out. This method is based on the measurement of electrical resistivity variations of different subsoil geological materials, since rocks and soils, depending on their mineralogical composition, texture, porosity, fracturing and the content/chemical composition of the water contained in them, could exhibit anomalous, low electrical resistivity. The results revealed that no low resistivity values were found, typical of areas that normally exhibit natural or anthropogenic geochemical anomalies, or even, in more extreme cases, contaminations with acid drainages whose acidity and resistivity would be even lower and more anomalous.

Abstract
The Alto do Sobrido and Ribeiro da Serra Mines, are two antimony-gold mines located in Gondomar, Portugal, and are part of the Dúrico-Beirão Mining District (DBMD). In this work, we use four geophysical methods, such as gravity, radiometry, magnetic and electromagnetic, to improve the knowledge about these mineralizations and the lithologies and structures associated with them. These four methods allowed us to study these mineralizations through different physical properties. The gravimetric method allowed us to add more data to the hypothesis that the gold-antimony mineralizations of the DBMD could be genetically associated with a non-outcropping granite intrusion, which functioned either as a heat engine that promoted the circulation of fluids and/or as a source of fluids and metals itself. A 2D model was proposed, created with both modelling and inversion, to show that the presence of this granite could indeed fit the response of the negative anomalies found in the residual anomaly. The radiometric method was used mainly as a mapping tool, where we were able to distinguish between some of the lithologies of the area, like the Lower Ordovician quartzites and the metasediments of the Middle Ordovician to the Carboniferous, but also to observe different element concentrations within the Pre-Ordovician Schist-Greywacke Complex (SGC). These variations within the SGC lithology don’t have a clear explanation as to why they occur. Still, we believe that they could occur due to the influence of the abovementioned non-outcropping granite. With the very low frequency (VLF) electromagnetic method, it was possible to locate areas of lower resistivities that correspond to the location of several known mineralized veins, as well as the probable location for a new vein. It was also possible to observe some weathered rocks near faults and fractures associated with the Dúrico-Beirão Shear Zone (DBSZ). With the magnetic method, it is possible to contribute to areas with the prevalence of lithologies and minerals with higher magnetic susceptibilities. Several magnetic anomalies found near the Alto do Sobrido mining works correspond to the mineralized veins paragenesis. Other anomalies appear to be related to the location of faults and fractures associated with the DBSZ. The use of all these methods allowed us to observe the mineralization responses and its associated lithologies and structures through the different geophysical properties while adding knowledge about the genesis of these mineralizations and possibly the location of new mineralized veins.

Abstract
The region West of Estarreja is topographically flat and, from the geological point of view, characterized by Quaternary and Cretaceous formations that lie discordantly over Pre-Cambrian schists. The topography of this contact is poorly known and, therefore, is investigated here. Data from drilling, electrical resistivity profiles and gravity mapping, over a 30 km2 area bounded on the Eastern side by the “Norte” Railway line and on the Western by the Ria de Aveiro that separates Murtosa from Torreira, are jointly interpreted to produce a robust model for the topography of the bedrock. Hence, NW-SE alignments, inferred by previous works, are clearly identified. Bedrock depressions are also proposed and agree with previous geophysical models from areas to the South of the region herein investigated. © 2022 LNEG – Laboratório Nacional de Energia e Geologia IP.

Abstract
<p>The Alto do Sobrido (AS) and Ribeiro da Serra (RS) Mines are old Sb-Au explorations. These are located in Gondomar, Portugal, on the inverse limb of the well-known structure called Valongo Anticline. In the AS Mine, the mineralization occurs near the contact between the Schist-Greywacke Complex (CXG) (Precambrian and/or Cambrian(?)) and the breccia of the base of the Carboniferous. In the RS Mine, the mineralization occurs only on the CXG. In both mines, the Sb-Au mineralization occurs in quartz veins and some stockworks.</p><p>A spatial correlation between the Sb-Au mineralization and the post-orogenic granites occurs in the Dúrico-Beirã Region according to Gumiel & Arribas (1987). Couto et al. (2007) also acquired data that suggests a genetic connection between this mineralization and non-outcropping granites. These granites may have been the source of fluids and a heat source that improved hydrothermal circulation and they have been observed in one of the RS Mine’s galleries.</p><p>With this hypothesis in mind, we intend to compare the data from a radiometric survey, which is a method that is radiometrically sensitive to K, Th and U at the near-surface, to the data from a gravimetric survey, which is a method that is sensitive to density anomalies at greater depths, in order to show if these granites could have chemically influenced its embedding rocks.</p><p>To make this comparison, we used the residual anomaly map from our gravimetric survey and the four maps obtained in the radiometric survey (total concentrations, K, eTh and eU). Firstly, we normalized all the grid maps to obtain grids with values between -1 and 1. Once this was complete, we multiplied each of the four radiometry maps to the residual anomaly map, obtaining the comparison maps.</p><p>On the resulting maps, we can observe high values in 3 different areas. The first corresponds to a lower value of gravimetric anomaly and a lower value of concentrations of all the elements. This area is located where the hypothesized non-outcropping granites are situated. The second area corresponds to high values on both methods. This matches the location of the lithologies from the Middle Ordovician to the Carboniferous, which are rocks of higher densities and higher concentration values of K, eTh and eU. The third area consists of lower gravimetric anomalies and lower concentrations of K and eU, and coincides with the location of the Ordovician quartzites. This area isn’t as visible on the eTh map, which is consistent with what was observed on the field.</p><p>We consider this approach to be a practical method to correlate the results of these two methods and an attempt to understand how the granite located at depth could have influenced these lithologies that today outcrop.</p><p><strong>References</strong></p><p>Gumiel, P., Arribas, A., 1987. Antimony Deposits in the Iberian Peninsula. Economic Geology, Volume 82, pp 1453-1463.</p><p>Couto, H., Borges, F. S., Roger, G., 2007. Late Palaeozoic orogenic gold-antimony deposits from the Dúrico-Beirã area (North Portugal) and their relation with hidden granitic apexes. Ninth Biennial SGA Meeting, Dublin. pp 609-612.</p>

Abstract
Robust wireless communication networks are a cornerstone of the modern world, allowing data to be transferred quickly and reliably. Establishing such a network at sea, a Maritime Internet of Things (MIoT), would enhance services related to safety and security at sea, environmental protection, and research. However, given the remote and harsh nature of the sea, installing robust wireless communication networks with adequate data rates and low cost is a difficult endeavor. This paper reviews recent MIoT systems developed and deployed by researchers and engineers over the past few years. It contains an analysis of short-range and long-range over-the-air radio-frequency wireless communication protocols and the synergy between these two in the pursuit of an MIoT. The goal of this paper is to serve as a go-to guide for engineers and researchers that need to implement a wireless sensor network at sea. The selection criterion for the papers included in this review was that the implemented wireless communication networks were tested in a real-world scenario.

Abstract
A linear electromagnetic energy harvesting device for underwater applications, fabricated with a simple manufacturing process, was developed to operate with movement frequencies from 0.1 to 0.4 Hz. The generator has two coils, and the effect of the combination of the two coils was investigated. The experimental study has shown that the energy capture system was able to supply energy to several ocean sensors, producing 7.77 mJ per second with wave movements at 0.4 Hz. This study shows that this energy is enough to restore the energy used by the battery or the capacitor and continue supplying energy to the sensors used in the experimental work. For an ocean wave frequency of 0.4 Hz, the generator can supply power to 8 sensors or 48 sensors, depending on the energy consumed and its optimization.