Research on WASH sector, environment and water resources in the Central Rift Valley of Ethiopia

Peer ReviewedPostprint (published version

Anatomical and functional brain approach along short abrupt changes in G-levels

To conduct experiments under abrupt changes in g-levels, a single-engine aerobatic aircraft has been used, providing 6-8 seconds of reduced gravity, preceded and followed by 5-7 seconds of hypergravity periods. Due to the specific conditions of the flight and previous findings [1], the hypothesis of the present work lies on the idea that some sensory inputs could have a notorious effect on brain final responses when gravity is altered. Therefore, this study focuses on the evaluation of such hypothesis, based on the analysis of the evolution in time of intracranial activity of limbic, visual and auditory cortices. Five subjects (N=5, age 41¿14 years) have flown in parabolic flight with their eyes both open and closed. Electroencephalogram signals were recorded with an Emotive Epoc headset, synchronized with a triaxial accelerometer. The intracranial brain bioelectric activity (standardized current density) throughout the parabola, was calculated by applying Standard Low Resolution Brain Electromagnetic Tomography, and it was analyzed for the limbic, visual and auditory cortices. Intracranial activity of the Temporal, Parietal and Occipital lobes were carried out as well in order to compare the different periods/phases of the flight. Results detected a lower brain activity during the hypogravity phase in all lobes and cortices, only in the case of open eyes. The bioelectrical brain activity along the parabola showed similar patterns in all lobes and cortices, when visual inputs are highlighted. Suppressing the sight, two major behaviors were detected in brain activity: one for temporal lobe and auditory cortex, and second one for the rest of the lobes and visual cortex. It Seemed that, flying with closed eyes, other sensory stimuli were enhanced, in this case the auditory cortex. To confirm the validity of the results two-way ANOVA (factors lobe/phases) and Fisher post hoc test have been applied on mean intracranial activity values in all cases. Spectral entropy evolution in time has been considered as a fast indicator of the sudden extracranial brain activity variation during short g-changes. For open eyes, spectral entropy values indicated a slight decrease at the onset of the hypogravity phase, whereas in case of closed eyes, this change was detected in the last seconds of the parabola, even though these fluctuations were statistically non-significant. Results suggest that some of the sensory inputs can indeed have an impact on brain final response, when gravity conditions are altered.Peer ReviewedPostprint (published version

New multifunctional sulfonato-containing metal phosphonates proton conductors

Anchoring of acidic functional groups to organic linkers acting as ligands in metal phosphonates has been demonstrate to be a valid strategy to develop new proton conductor materials, which exhibit tunable properties and are potentially applicable to proton exchange membranes, such as those used in PEMFCs [1,2]. In this work, the structural and proton conductivity properties of several families of divalent and trivalent metal amino-sulfophosphonates are presented. The chosen ligand, (H2O3PCH2)2-N-(CH2)2-SO3H, was reacted with the appropriate metal salt using highthrough-put screening and/or microwave-assisted synthesis. Different crystal structures haven been solved displaying a variety of metal ligand coordination modes, in whose frameworks acidic groups contribute to create strong H-bond networks; together with lattice and bound water molecules. Proton conductivity values oscillate between 10-4 and 10-2 S.cm-1, at 80 ºC and 95 % relative humidity, most of them showing activation energies characteristic of a Grotthuss-type proton transport mechanism.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. MINECO: MAT2016-77648-R Junta de Andalucía: P-12-FQM-1656 y FQM-11

Fullerene-based molecular nanobridges: A first-principles study

Building upon traditional quantum chemistry calculations, we have implemented an {\em ab-initio} method to study the electrical transport in nanocontacts. We illustrate our technique calculating the conductance of C$_{60}$ molecules connected in various ways to Al electrodes characterized at the atomic level. Central to a correct estimate of the electrical current is a precise knowledge of the local charge transfer between molecule and metal which, in turn, guarantees the correct positioning of the Fermi level with respect to the molecular orbitals. Contrary to our expectations, ballistic transport seems to occur in this system.Comment: 4 pages in two-column forma

Preparation of N-doped Carbon/Metal Phosphides as Promising Trifunctional Electrocatalysts Toward the OER, ORR and HER

Sustainable energy storage and conversion technologies, such as electrochemical water splitting and fuel cells, attracts increasing attention as alternative processes to advance toward a global decarbonation. However, the high cost, scarcity, and poor stability of the most active electrocatalysts, mainly based on noble metal (Pt, RuO2, IrO2,…), difficult severely their large-scale production and use. In this regard, the development of earth-abundant electrocatalysts, with high activity for the different processes, is needed. Several imidazole-containing metal etidronates, MLIm-n (M2+= Fe, Co, Ni and solid solutions; L= ETID; Im= Imidazole; n= [0, 3]), were prepared using different synthetic procedures. Thermal reduction of MLIm-n in 5%H2–Ar at different temperatures resulted on core–shell N-doped carbon/TMPs with variable content of MP and MxP as crystalline phases. Their electrocatalytic activities have been widely studied by cyclic and linear sweep voltammetry, impedance spectroscopy, transmission electron microscopy, and XPS analysis. Preliminary results reveal that factors such as the presence of the imidazole and the metal coordination environment in the precursor samples determine the final composition and electrochemical properties of the resulting pyrolyzed derivatives. So, the Co2+- derivative, CoLIm-0@800, with a composition CoP/Co2P= 80/20 wt. %, exhibited the best electrocatalytic properties toward OER/ORR/HER as well as good capabilities as anode for overall water splitting in comparison to the expensive reference RuO2 electrocatalyst

A new vertebrate assemblage from the matute formation of the Cameros Basin (Ágreda, Spain): implications for the diversity during the jurassic/cretaceous boundary

Altres ajuts: Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.The Ribota site (Ágreda, Soria, Spain) is a new locality in the Matute Formation (Tithonian-Berriasian) composed of several carbonate layers, outstandingly rich in macrovertebrate remains. Fossils show an unusual replacement of the original bioapatite by quartz, and are found as positive reliefs protruding from lacustrine limestone beds. This type of conservation has allowed the identification of around one hundred vertebrate bone accumulations in an outcrop of more than 10 hectares. Osteichthyans (articulated partial skeletons, cranial material, and isolated postcranial bones and scales), crocodylomorphs (disarticulated cranial material, isolated teeth, vertebrae and osteoderms), turtles (partial carapaces and plastra, but also isolated plates) and pterosaurs (cranial and appendicular elements) have been identified. Around 80 specimens have been collected and a preliminary study of part of the collection (35 specimens) has allowed the identification of at least 5 different taxa: Halecomorphi indet., Neoginglymodi indet., Goniopholididae indet., Testudinata indet., and Pterodactyloidea indet. This new site represents one of the few sites from this time interval preserved in a fully lacustrine environment, so these vertebrate assemblages are unique and composed of different animals that presumably lived around and within the lake. They are dominated by aquatic and amphibian vertebrates and was formed by attrition in this lacustrine environment, possibly far from the lake shoreline. These macrovertebrate assemblages provide new data about the diversity in the faunal ecosystems from the Jurassic/Cretaceous transition of the Iberian Basin Rift System

A first-principles approach to electrical transport in atomic-scale nanostructures

We present a first-principles numerical implementation of Landauer formalism for electrical transport in nanostructures characterized down to the atomic level. The novelty and interest of our method lies essentially on two facts. First of all, it makes use of the versatile Gaussian98 code, which is widely used within the quantum chemistry community. Secondly, it incorporates the semi-infinite electrodes in a very generic and efficient way by means of Bethe lattices. We name this method the Gaussian Embedded Cluster Method (GECM). In order to make contact with other proposed implementations, we illustrate our technique by calculating the conductance in some well-studied systems such as metallic (Al and Au) nanocontacts and C-atom chains connected to metallic (Al and Au) electrodes. In the case of Al nanocontacts the conductance turns out to be quite dependent on the detailed atomic arrangement. On the contrary, the conductance in Au nanocontacts presents quite universal features. In the case of C chains, where the self-consistency guarantees the local charge transfer and the correct alignment of the molecular and electrode levels, we find that the conductance oscillates with the number of atoms in the chain regardless of the type of electrode. However, for short chains and Al electrodes the even-odd periodicity is reversed at equilibrium bond distances.Comment: 14 pages, two-column format, submitted to PR

Structural variability in M2+ 2-hydroxyphosphonoacetate moderate proton conductors

The structural variability of two series of Mg2+- and Zn2+- 2-hydroxyphosphonoacetates have been studied in the range of 25–80 °C and 95 % relative humidity in order to correlate the structure with the proton conductivity properties. In addition to selected previously reported 1D, 2D and 3D materials, a new compound, KZn6(OOCCH(OH)PO3)4(OH)·5H2O (KZn6-HPAA-3D), has been prepared and thoroughly characterized. The crystal structure of this solid, solved ab initio from synchrotron X-ray powder diffraction data, consists of a negatively charged 3D framework with K+ ions, as compensating counterions. It also contains water molecules filling the cavities in contrast to the potassium-free 3D anhydrous NH4Zn(OOCCH(OH)PO3) (NH4Zn-HPAA-3D). In the range of temperature studied, the 1D materials exhibit a 1D → 2D solid-state transition. At 80 °C and 95 % RH, the 2D solids show moderate proton conductivities, between 2.1 × 10 − 5 S·cm − 1 and 6.7 × 10− 5 S·cm− 1. The proton conductivity is slightly increased by ammonia adsorption up to 2.6 × 10 − 4 S·cm − 1, although no ammonia intercalation was observed. As synthesized KZn6-HPAA-3D exhibits a low proton conductivity, 1.6 × 10− 6 S·cm− 1, attributed to the basic character of the framework and a low mobility of water molecules. However, this solid transforms to the 2D phase, Zn(OOCCH(OH)PO3H)·2H2O, upon exposure to dry HCl(g), which enhances the proton conductivity with respect to the as-synthesized 2D material (4.5 × 10− 4 S·cm− 1). On the other hand, NH4Zn-HPAA-3D exhibited a higher proton conductivity, 1.4 × 10− 4 S·cm− 1, than the K+ analog.Proyecto MAT2013-41836-R del MINECO y proyecto P12-FQM-1656 de la Junta de Andalucí

How to measure student's performance in PBL?

[EN] In this paper, we present an analysis of metrics for teamwork efficiency in University degrees, by considering Project Based Learning as a teaching methodology. We defined indicators to evaluate the ability to prioritize tasks, the group communication and the produced value. Such parameters were designed to provide objective information about teamwork efficiency. To test the effectiveness of the proposed indicators, an experiment based on a classic team-building game was performed in the context of the Interactive Technologies Degree at Universitat Politècnica de València. Students were divided into two groups (one from the first course and another the fourth course) and were asked to solve a problem in a limited amount of time. Our hypothesis was that the group corresponding to the fourth course would achieve higher teamwork efficiency because of their experience with the Project Based Learning methodology. After measuring the proposed indicators and other state-of-the-art parameters, we assessed the evolution and improvement of teamwork efficiency by comparing the results of both sets of metrics. Finally, we concluded that the presented metrics can be useful for teamwork efficiency evaluation, but also for students to manage their work.This work has been partially financed by UPV-Innovation Project PIME-I 1776 (2022-2024).Pérez Pascual, MA.; Alberola Oltra, JM.; Marín-Roig Ramón, J.; Toledo Alarcón, JF.; Palacio Samitier, D.; Giménez López, JL.; Heras, S.... (2023). How to measure student's performance in PBL?. IATED. 1-9. https://doi.org/10.21125/inted.2023.08461

Effect of ground-cover management on predatory mites (Acari: Phytoseiidae) in a Mediterranean vineyard

Most predatory mites belong to the family Phytoseiidae (Acari). Throughout the world, phytoseiids are involved in the biological control of phytophagous mites in vineyards. Conservative strategies, including cover-vegetation management, are essential to achieve environmentally friendly viticulture. The abundance and diversity of phytoseiid mites in the grapevine canopy and the vegetal ground cover of a Mediterranean vineyard were surveyed by weekly samplings, from early May until the end of September for two years (2016 and 2017). Three types of soil management without herbicide application were analysed and referred to as "Tillage", "Spontaneous Cover", and "Flower-driven Cover" treatments. Six phytoseiid species were collected on the grapevine canopy, with Typhlodromus pyri being the dominant species (99.5 %). Five phytoseiid species were recorded in the ground cover, with Typhlodromus and Neoseiulus as the major genera. The Flower-driven Cover treatment showed the highest abundance of phytoseiids in the grapevine canopy. However, both species richness and abundance of phytoseiid mites on the ground-cover vegetation were highest in the Spontaneous Cover treatment. These observations suggest that improving vegetation cover would promote both the abundance and diversity of phytoseiid mites in vineyards because the greater supply of pollen would enhance their survival. Therefore, the use of cover crops in vineyards represents a means of improving vineyard ecosystems by conservative biological control