Mineralogical and thermal characterization of kaolinitic clays from Terra Alta (Catalonia, Spain)

This research characterizes the kaolinitic clays from Cretaceous-Paleocene lateritic depòsits of Terra Alta (south Catalonia) to evaluate their possible applications. The outcrops and quarries belong to the Horta de Sant Joan and Pinell de Brai areas. The chemical composition, mineralogy, rheological behavior, particle size distribution and plasticity are determined. The Fe and Ti4+ contents prevent them from being directly used as raw material for white ceramics. The mineralogy consists of kaolinite with quartz, illite, hematite, and minor K-feldspar and calcite. Most of the area comprises medium plastic clays that are classified as fired clays and can be used as ceramic and construction materials. In Horta de Sant Joan, a kaolinitic-rich level, up to 75 wt % of kaolinite, is highly crystalline with low plasticity and can be classified as flint clay, useful as a refractory clay. The evaluated kaolinitic clays can also be used to obtain a triaxial ceramic when they are mixed with feldspar to act as a fluxing agent and chamotte

Propuesta innovadora en el marco de la formación del profesorado para la enseñanza secundaria en la especialidad biologia geologia

Strategies to train students in cooperative work through leadership are developed in the Máster de Formación del Profesorado. Aims are to motivate learning within a working team with a leader and leader assistant. The leader will encourage team work, accept responsibilities and organize commands properly by planning the study personally and collectively. The leader assistant's should execute jobs commanded by the leader. The teacher will never be its main source of information

The use of tailings to make glass as an alternative for sustainable environmental remediation: the case of Osor, Catalonia, Spain

Tailings from the Osor fluorite mines release large amounts of potentially toxic elements into the environment. This work is a proposal to remove these waste materials and use them as a raw material in the manufacture of glass. The chemical composition of the tailings was determined by X-ray fluorescence and the mineralogy by X-ray diffraction. Waste materials have SiO2, Al2O3 and CaO contents suitable for a glass production, but Na as NaCO3 has to be added. Two glass formulations, with 80-90% of the residue and 10-20% Na2CO3, have been produced. The crystallization temperatures, obtained by differential thermal analysis, were 875 and 901 C, and the melting temperatures were 1220 and 1215 C for the G80-20 and G90-10 glasses, respectively. The transition temperatures of glass were 637 and 628 C. The crystalline phases formed in the thermal treatment to produce devitrification were nepheline, plagioclase and diopside in the G80-20 glass, and plagioclase and akermanite-gehlenite in the G90-10 glass. The temperatures for the fixed viscosity points, the working temperatures and the coeffcient of expansion were obtained. The chemical stability of the glass was tested and results indicate that the potentially toxic elements of the tailings were incorporated into the glass structure

Element Accumulation Patterns of Native Plant Species under the Natural Geochemical Stress

A biogeochemical study of more than 20,000 soil and plant samples from the North Caucasus, Dzungarian Alatau, Kazakh Uplands, and Karatau Mountains revealed features of the chemical element uptake by the local flora. Adaptation of ore prospecting techniques alongside environmental approaches allowed the detection of geochemical changes in ecosystems, and the lessons learned can be embraced for soil phytoremediation. The data on the influence of phytogeochemical stress on the accumulation of more than 20 chemical elements by plants are considered in geochemical provinces, secondary fields of deposits, halos surrounding ore and nonmetallic deposits, zones of regional faults and schist formation, and over lithological contact lines of chemically contrasting rocks overlain by 5-20 m thick soils and unconsolidated cover. We have corroborated the postulate that the element accumulation patterns of native plants under the natural geochemical stress depend not only on the element content in soils and the characteristics of a particular species but also on the values of ionic radii and valences; with an increase in the energy coefficients of a chemical element, its plant accumulation decreases sharply. The contribution of internal factors to element uptake from solutions gives the way to soil phytoremediation over vast contaminated areas. The use of hyperaccumulating species for mining site soil treatment depends on several external factors that can strengthen or weaken the stressful situation, viz., the amount of bedrock exposure and thickness of unconsolidated rocks over ores, the chemical composition of ores and primary halos in ore-containing strata, the landscape and geochemical features of sites, and chemical element migration patterns in the supergene zone

Transición del instituto a la universidad en el ámbito de las ciencias de la tierra

Peer ReviewedObjectius de Desenvolupament Sostenible::4 - Educació de QualitatPostprint (published version

Impacts of use and abuse of nature in Catalona with proposal 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

Podem fer ApS virtual?: creació d’una plataforma de difusió d’activitats de ciències de la terra per a estudiants d’ESO [Informe final PID 2020PID-UB/039]

Projecte PID: 2020PID-UB/039El projecte proposa la creació de diverses activitats virtuals, dinàmiques i vives, allotjades en el servidor de la UB, i que serveixin com a plataforma de llançament per a la incorporació, la difusió i la implementació de noves propostes futures amb un marcat caire innovador. Totes s’emmarquen en l’àmbit de l’educació i divulgació científica dins de les assignatures de Treball de Final de Grau (TFG) i de màster (TFM) que es realitzen a les facultats de Ciències de la Terra i Biologia de la Universitat de Barcelona. Aquesta actuació ha impulsat definitivament la metodologia docent d’Aprenentatge-Servei (ApS) a la Facultat de Ciències de la Terra i en ensenyaments que continguin assignatures relacionades amb les Ciències de la Terra i el Medi Ambient, i han millorat la transferència de coneixements geològics cap a la Societat.S’han generat 3 projectes virtuals d'accés gratuït que inclouran conceptes de ciències de caire transversal i dinamitzador, Aquests projectes han estat dissenyats per l’alumnat del grau de geologia, el grau de ciències ambientals i el màster de formació del professorat de l’especialitat de Biologia i Geologia en el marc dels seus TFG i TFM. Les activitats estan relaciones amb el currículum de Ciències de la Terra, i destinades a l’estudiat d’ESO i Batxillerat. El desenvolupament de les activitats, així, implica també la seva implementació i avaluació en almenys un institut pilot.En definitiva, es vol demostrar que la resposta a la pregunta proposada al títol del projecte “Podem fer ApS virtual?” és clarament sí, tot i les aparents restriccions i contradiccions que sembla implicar el propi concepte ApS amb la metodologia docent virtual

Erythropoietin levels are not independently associated with malaria-attributable severe disease in Mozambican children.

BACKGROUND: Severe malaria is difficult to differentiate from other forms of malaria or other infections with similar symptoms. Any parameter associated to malaria-attributable severe disease could help to improve severe malaria diagnosis. METHODOLOGY: This study assessed the relation between erythropoietin (EPO) and malaria-attributable severe disease in an area of Mozambique with moderate malaria transmission. 211 children <5 years, recruited at Manhiça District Hospital or in the surrounding villages, were included in one of the following groups: severe malaria (SM, n = 44), hospital malaria without severity (HM, n = 49), uncomplicated malaria (UM, n = 47), invasive bacterial infection without malaria parasites (IBI, n = 39) and healthy community controls (C, n = 32). Malaria was diagnosed by microscopy and IBI by blood/cerebrospinal fluid culture. PRINCIPAL FINDINGS: Mean EPO concentration in the control group was 20.95 U/l (SD = 2.96 U/l). Values in this group were lower when compared to each of the clinical groups (p = 0.026 C versus UM, p<0.001 C vs HM, p<0.001 C vs SM and p<0.001 C vs IBI). In the 3 malaria groups, values increased with severity [mean = 40.82 U/l (SD = 4.07 U/l), 125.91 U/l (SD = 4.99U/l) and 320.87 U/l (SD = 5.91U/l) for UM, HM and SM, respectively, p<0.001]. The IBI group [mean = 101.75 U/l (SD = 4.12 U/l)] presented lower values than the SM one (p = 0.002). In spite of the differences, values overlapped between study groups and EPO levels were only associated to hemoglobin. Hemoglobin means of the clinical groups were 93.98 g/dl (SD = 14.77 g/dl) for UM, 75.96 g/dl (SD = 16.48 g/dl) for HM, 64.34 g/dl (SD = 22.99 g/dl) for SM and 75.67 g/dl (SD = 16.58 g/dl) for IBI. CONCLUSIONS: Although EPO levels increase according to malaria severity and are higher in severe malaria than in bacteremia, the utility of EPO to distinguish malaria-attributable severe disease is limited due to the overlap of values between the study groups and the main role of hemoglobin in the expression of EPO

Fabrication of glass-based products as remediation alternative for contaminated urban soils of Barcelona

Peer ReviewedPostprint (published version