Hydrothermally treated vermiculites: Ability to support products for CO2 adsorption and geological implications

The proposal of this research was to obtain products with higher porosity and specific surface area than the raw vermiculite for its possible application as a support material for CO2 adsorption. In addition, it was proposed to analyze the possible geological implications of the products resulting from the hydrothermal treatment of vermiculites in relation to their genesis. Hydrothermal treatment in the presence of CO2, at low temperature and pressure conditions, was carried out in two vermiculites from Uganda and China, with different behavior to thermal exfoliation and microwave irradiation. The untreated and treated samples were characterized by several techniques: X-ray diffraction (XRD) for obtaining the mineral composition; thermogravimetry (TG - DTG) for analyzing the thermal behavior; and BET isotherms for obtaining textural parameters. In addition, the hydrothermal solutions were characterized by the pH and the measuring of the lixiviated elements with inductively coupled plasma mass spectrometry (ICP-MS). Vermiculite can be a suitable support for CO2 adsorbents, based on the SBET and Qm values, and it is susceptible to carbonation. The hydrothermal treatment produced water loss in the expanded vermiculites by CO2 replacement; as consequence, amorphization occurred in the purer Ugandan sample, and vermiculitization occurred in the less pure sample from China.The vermiculitization process indicates that the geological origin of vermiculite may be hydrothermal from phlogopite.Ministry of Science and Innovation, Spain (MICINN) Spanish Government PCI2019-111931-2European Regional Development Fund (ERDF) - Next Generation / EU progra

Carbonate Minerals’ Precipitation in the Presence of Background Electrolytes: Sr, Cs, and Li with Different Transporting Anions

Carbonate minerals are largely associated with many geological and biological environments as well as several industrial and technological processes. The crystalline characteristics of these mineral phases can be modified by background salts present in the solution due to the effect of different electrolytes on the dynamics of ion-water interactions and ionic strength during precipitation. In the current research, we studied the effect of the presence of several electrolytes (i.e., Cs, Li, and Sr), combined with chloride and carbonate as transporting anions, on the growth and mineral evolution processes of carbonate precipitation in solution. The electrolyte composition during the reaction (experimental times from 24 h up to 30 days) determined the formation of specific calcium carbonate polymorphs. The Li presence induced the formation of vaterite which was progressively transformed into calcite during the reaction time, while Cs stabilized the calcite formation. The Sr presence in the system caused the precipitation of strontianite with modifications in its cell parameters and the structural arrangement of the carbonate molecular group. During the mineral evolution considering chloride and carbonate experimental set-ups, several compositional and cell parameters/crystallinity variations of the carbonated phases were also observed. A better understanding of the relationship between the compositional properties of the aqueous solvent and the crystallization mechanisms can contribute to a deeper comprehension of the mineral precipitation and transformation in different multicomponent solutions that occur in natural environments and in controlled synthesis processesSpanish Ministry of Economy and Competitiveness, grant number PCI2019-111931-2European Regional Development Fund (ERDF)—Next Generation/EU progra

Comparative Study of the Mineralogy and Chemistry Properties of Elephant Bones: Implications during Diagenesis Processes

Elephants are currently the largest terrestrial mammals, along with their extinct ancestor the mammoth. These species are of great interest due to their geographic distribution and ecological importance. However, the bone mineral characteristics of their skeleton as well as their alteration during burial processes over millions of years have been poorly investigated. In the current research, we analyzed the compositional and structural mineral properties of different types (i.e., long and flat bones) of elephant and mammoth bones. For this purpose, we performed a comparative study between these bone types using complementary analytical techniques based on X-ray diffraction, thermogravimetry, Fourier transform infrared spectroscopy, scanning electron microscopy, and inductively coupled plasma spectroscopic analysis. The chemical composition of the samples shows a relative loss of a considerable percentage of water and organic matter components for the fossilized bone, accompanied by a higher bone mineralization degree and the presence of other crystalline phases (i.e., calcite and pyrite) related to a certain degree of diagenesis alteration. Our results also show a variation in the crystalline properties of mammoth bone related to the recrystallization process during the dissolution–precipitation transformation through diagenetic burial. This research provides relevant information for understanding the mineral properties of different types of bones and their possible changes during diagenesis.Spanish Government CGL2015-64683-P PID2020-116660GB-I00European Regional Development Fund (ERDF)-Next Generation-EU progra

Evaluation of the remineralizing capacity of silver diamine fluoride on demineralized dentin under pH-cycling conditions

Objective: (1) to determine the effects of the silver diamine fluoride (SDF) and sodium fluoride (NaF) in demineralized dentin exposed to an acid challenge by pH-cycling, (2) to evaluate the remineralizing capacity of SDF/NaF products based on the physicochemical and mechanical properties of the treated dentin surfaces. Methodology: In total, 57 human molars were evaluated in different stages of the experimental period: sound dentin – negative control (Stage 1), demineralized dentin – positive control (Stage 2), and dentin treated with SDF/NaF products + pH-c (Stage 3). Several commercial products were used for the SDF treatment: Saforide, RivaStar, and Cariestop. The mineral composition and crystalline and morphological characteristics of the dentin samples from each experimental stage were evaluated by infrared spectroscopy (ATR-FTIR), X-ray diffraction, and electron microscopy (SEM-EDX) analytical techniques. Moreover, the mechanical response of the samples was analyzed by means of the three-point bending test. Statistics were estimated for ATR-FTIR variables by Wilcoxon test, while the mechanical data analyses were performed using Kruskal-Wallis and Mann Whitney U tests. Results: Regarding the chemical composition, we observed a higher mineral/organic content in the SDF/NaF treated dentin + pH-c groups (Stage 3) than in the positive control groups (Saforide p=0.03; Cariestop p=0.008; RivaStar p=0.013; NaF p=0.04). The XRD results showed that the crystallite size of hydroxyapatite increased in the SDF/NaF treated dentin + pH-c groups (between +63% in RivaStar to +108% in Saforide), regarding the positive control. SEM images showed that after application of the SDF/NaF products a crystalline precipitate formed on the dentin surface and partially filled the dentin tubules. The flexural strength (MPa) values were higher in the dentin treated with SDF/NaF + pH-c (Stage 3) compared to the positive control groups (Saforide p=0.002; Cariestop p=0.04; RivaStar p=0.04; NaF p=0.02). Conclusions: The application of SDF/NaF affected the physicochemical and mechanical properties of demineralized dentin. According to the results, the use of SFD/NaF had a remineralizing effect on the dentin surface even under acid challenge

Formación de Estroncianita y Witherita a través del Reemplazamiento de Cristales de Calcita

Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEMinisterio de EconomíaMinisterio de Universidadespu

Life-history traits of the giant squid Architeuthis dux revealed from stable isotope signatures recorded in beaks

Peer reviewedPreprin

Impacts of Use and Abuse of Nature in Catalonia with Proposals for Sustainable Management

This paper provides an overview of the last 40 years of use, and in many cases abuse, of the natural resources in Catalonia, a country that is representative of European countries in general, and especially those in the Mediterranean region. It analyses the use of natural resources made by mining, agriculture, livestock, logging, fishing, nature tourism, and energy production and consumption. This use results in an ecological footprint, i.e., the productive land and sea surface required to generate the consumed resources and absorb the resulting waste, which is about seven times the amount available, a very high number but very similar to other European countries. This overexploitation of natural resources has a huge impact on land and its different forms of cover, air, and water. For the last 25 years, forests and urban areas have each gained almost 3% more of the territory at the expense of agricultural land; those municipalities bordering the sea have increased their number of inhabitants and activity, and although they only occupy 6.7% of the total surface area, they account for 43.3% of the population; air quality has stabilized since the turn of the century, and there has been some improvement in the state of aquatic ecosystems, but still only 36% are in good condition, while the remainder have suffered morphological changes and different forms of nonpoint source pollution; meanwhile the biodiversity of flora and fauna remains still under threat. Environmental policies do not go far enough so there is a need for revision of the legislation related to environmental impact and the protection of natural areas, flora, and fauna. The promotion of environmental research must be accompanied by environmental education to foster a society which is more knowledgeable, has more control and influence over the decisions that deeply affect it. Indeed, nature conservation goes hand in hand with other social and economic challenges that require a more sustainable vision. Today's problems with nature derive from the current economic model, which is environmentally unsustainable in that it does not take into account environmental impacts. Lastly, we propose a series of reasonable and feasible priority measures and actions related to each use made of the country's natural resources, to the impacts they have had, and to their management, in the hope that these can contribute to improving the conservation and management of the environment and biodiversity and move towards sustainability

Impacts of Use and Abuse of Nature in Catalonia with Proposals for Sustainable Management

This paper provides an overview of the last 40 years of use, and in many cases abuse, of the natural resources in Catalonia, a country that is representative of European countries in general, and especially those in the Mediterranean region. It analyses the use of natural resources made by mining, agriculture, livestock, logging, fishing, nature tourism, and energy production and consumption. This use results in an ecological footprint, i.e., the productive land and sea surface required to generate the consumed resources and absorb the resulting waste, which is about seven times the amount available, a very high number but very similar to other European countries. This overexploitation of natural resources has a huge impact on land and its different forms of cover, air, and water. For the last 25 years, forests and urban areas have each gained almost 3% more of the territory at the expense of agricultural land; those municipalities bordering the sea have increased their number of inhabitants and activity, and although they only occupy 6.7% of the total surface area, they account for 43.3% of the population; air quality has stabilized since the turn of the century, and there has been some improvement in the state of aquatic ecosystems, but still only 36% are in good condition, while the remainder have suffered morphological changes and different forms of nonpoint source pollution; meanwhile the biodiversity of flora and fauna remains still under threat. Environmental policies do not go far enough so there is a need for revision of the legislation related to environmental impact and the protection of natural areas, flora, and fauna. The promotion of environmental research must be accompanied by environmental education to foster a society which is Land 2021, 10, 144 3 of 53 more knowledgeable, has more control and influence over the decisions that deeply affect it. Indeed, nature conservation goes hand in hand with other social and economic challenges that require a more sustainable vision. Today’s problems with nature derive from the current economic model, which is environmentally unsustainable in that it does not take into account environmental impacts. Lastly, we propose a series of reasonable and feasible priority measures and actions related to each use made of the country’s natural resources, to the impacts they have had, and to their management, in the hope that these can contribute to improving the conservation and management of the environment and biodiversity and move towards sustainability.info:eu-repo/semantics/publishedVersio

COSMO: Corrientes Marinas y Seguridad en el Medio Marino

Ejercicio internacional de salvamento y lucha contra la contaminación marina "Polex 24-17" organizado por la Dirección General de Marina Mercante y Salvamento Marítimo del 14 al 16 de junio de 2017 en SantanderDisponer en tiempo real de información sobre las corrientes oceánicas es clave para algunos de los servicios encomendados a la Sociedad de Salvamento y Seguridad Marítima y al Cuerpo Nacional de Policía (CNP). Un alto porcentaje de las emergencias de búsqueda de personas y náufragos, y de los incidentes de contaminación gestionados por Salvamento Marítimo, tienen lugar en zonas cercanas a la costa. Asimismo, el 71% de los casos de restos humanos no identificados (CSI) acontecidos en España durante el período 1968-2015 se da en zonas costeras. El proyecto COSMO busca mejorar la eficacia de las operaciones de búsqueda y de predicción de derivas, y mejorar la proporción de identificaciones positivas acelerando la resolución de casos de recuperación de restos humanosProyecto cofinanciado por el Ministerio de Economía Industria y Competitividad y Fondos FEDER de la UE (COSMO-CTM2016-79474-R, UE)Peer Reviewe