Formation of atom wires on vicinal silicon

The formation of atomic wires via pseudomorphic step-edge decoration on vicinal silicon surfaces has been analyzed for Ga on the Si(112) surface using Scanning Tunneling Microscopy and Density Functional Theory calculations. Based on a chemical potential analysis involving more than thirty candidate structures and considering various fabrication procedures, it is concluded that pseudomorphic growth on stepped Si(112), both under equilibrium and non-equilibrium conditions, must favor formation of Ga zig-zag chains rather than linear atom chains. The surface is non-metallic and presents quasi-one dimensional character in the lowest conduction band.Comment: submitte

Electrification of the boat fleet of the Albufera Natural Park of Valencia: methodology, economic and environmental assessments

[EN] This article presents a methodology for calculating the energy needs to propose the electrification of a fleet of small boats. A technical, economic and environmental analysis of the transition to electric mobility of the fleet of boats in the wetland of the Albufera Natural Park of Valencia (Spain) is presented and analysed. The environmental benefits of this transition are explored and an economic assessment is done, including the evaluation of the necessary public incentives to capture all the benefits related to this transition and make it feasible.This work was supported in part by the Spanish public administration under the grant FPU2016/00962 and by the Cátedra de Transición Energética Urbana (Las Naves-UPV).Bejarano-Cáceres, DS.; Ribó-Pérez, DG.; Alcázar-Ortega, M. (2020). Electrification of the boat fleet of the Albufera Natural Park of Valencia: methodology, economic and environmental assessments. Renewable Energy and Power Quality Journal. 18:144-149. https://doi.org/10.24084/repqj18.254S1441491

Ga-induced atom wire formation and passivation of stepped Si(112)

We present an in-depth analysis of the atomic and electronic structure of the quasi one-dimensional (1D) surface reconstruction of Ga on Si(112) based on Scanning Tunneling Microscopy and Spectroscopy (STM and STS), Rutherford Backscattering Spectrometry (RBS) and Density Functional Theory (DFT) calculations. A new structural model of the Si(112)6 x 1-Ga surface is inferred. It consists of Ga zig-zag chains that are intersected by quasi-periodic vacancy lines or misfit dislocations. The experimentally observed meandering of the vacancy lines is caused by the co-existence of competing 6 x 1 and 5 x 1 unit cells and by the orientational disorder of symmetry breaking Si-Ga dimers inside the vacancy lines. The Ga atoms are fully coordinated, and the surface is chemically passivated. STS data reveal a semiconducting surface and show excellent agreement with calculated Local Density of States (LDOS) and STS curves. The energy gain obtained by fully passivating the surface calls the idea of step-edge decoration as a viable growth method toward 1D metallic structures into question.Comment: Submitted, 13 pages, accepted in Phys. Rev. B, notational change in Fig.

Electrochemical degradation of norfloxacin using BDD and new Sb-doped SnO2 ceramic anodes in an electrochemical reactor in the presence and absence of a cation-exchange membrane

[EN] Electrochemical oxidation of Norfloxacin (NOR) in sodium sulphate media has been comparatively studied in an undivided and in a divided electrolytic cell both containing either a boron doped diamond (BDD) or a novel Sb-doped SnO2 ceramic anode under galvanostatic operation. The electro-oxidation was found to occur with first order kinetics mainly when using both anodes. The results showed the great oxidizing power of BDD in relation to the ceramic anode to convert NOR and all the intermediate accumulated into CO2. In the case of the BDD, although a 92% of TOC abatement was achieved, the complete mineralization was not possible probably due to the carboxylic acids still present in solution. On the contrary, for the ceramic electrode, which presented a maximum value of TOC removal of about 63%, the total mineralization of the aromatic oxidation intermediates was not reached under the experimental conditions. The use of a membrane divided cell showed positive aspects in terms of molecule degradation, degree of mineralization and current efficiency since prevents the intermediate products formed during the NOR oxidation process from being reduced on the cathode.Mora-Gómez, J.; Ortega Navarro, EM.; Mestre, S.; Pérez-Herranz, V.; García Gabaldón, M. (2019). Electrochemical degradation of norfloxacin using BDD and new Sb-doped SnO2 ceramic anodes in an electrochemical reactor in the presence and absence of a cation-exchange membrane. Separation and Purification Technology. 208:68-75. https://doi.org/10.1016/j.seppur.2018.05.017S687520

El parásito Saprolegnia diclina (Oomycetes), otra amenaza para la conservación species Atelopus nanay

Peer Reviewe

Uso de suplementos nutricionales y ayudas ergogénicas en jugadores profesionales de tenis.

Introduction: Nutritional supplements and ergogenic aids (NS&EA) are used between training/matches with the goal of enhancing tennis performance. Scientific literature about prevalence and use of NS&EA in professional tennis players is scarce. Objective: The aim of the study was to describe the NS&EA used by professional tennis players during a season. Methods: Using a validated self-administered questionnaire, 62 professional male and 9 professional female tennis players (11% in their gender specific top 100 tennis world ranking (i.e., ATP/WTA)) registered all the used NS&EA. Results: Eighty-one percent of the participants declared taking at least one NS&EA. Strength and conditioning trainers (S&C) and tennis coaches were the professionals who recommended most of the NS&EA in the players outside the TOP-100 (OT100; 50.7% and 39.1%, respectively). However, sports nutritionist were the principal advisors in the top-100 tennis players (T100; 62.5%). Sports drinks were the NS&EA most commonly used by all participants (81.7%). T100 participants used caffeine (p = 0.042), creatine (p = 0.001), iron (p = 0.013) and CHO-protein mix (p = 0.033) significantly more frequently that OT100 players. Conclusions: There is a high prevalence of NS&EA use among professional tennis players independently of their tennis ranking position. However, T100 tennis player have an increased use of certain substances such us caffeine, creatine, iron and CHO-Protein mix. For the rest of the studied NS&EA the use was similar between T100 and OT100 players. It is possible that the differences in NS&EA use between groups could be related to the different professionals on charge of nutritional advice in T100 vs OT100.Introducción: los suplementos nutricionales/ayudas ergogénicas (NS&EA) son utilizados en los entrenamientos/partidos de tenis con el objetivo de mejorar el rendimiento. Sin embargo, la literatura científica se encuentras escasos documentos científicos sobre el uso de estas sustancias en tenistas profesionales. Objetivo: describir el uso de NS&EA utilizados por tenistas profesionales durante una temporada. Métodos: se utilizó un cuestionario validado y se evaluó a 62 tenistas profesionales hombres y 9 mujeres (11% entre los 100 mejores del mundo). Resultados: el 81% de los participantes toman al menos un NS&EA. Los preparadores físicos (S&C) y entrenadores de tenis fueron los profesionales preferidos para recomendar NS&EA entre los jugadores fuera del TOP-100 (OT100, 50,7% y 39,1%, respectivamente). Sin embargo, los nutricionistas deportivos fueron los principales asesores de los jugadores entre los 100 mejores del mundo (T100, 62,5%). Las bebidas deportivas fueron los NS&EA más utilizados entre todos los participantes (81,7%). Los tenistas T100 utilizaron cafeína (p = 0,042), creatina (p = 0,001), hierro (p = 0.013) y mezcla de CHO-proteína (p = 0,033) significativamente más frecuentemente que los jugadores OT100. Conclusiones: existe una gran prevalencia de uso de NS&EA entre los tenistas profesionales. Además, los T100 presentan un mayor uso de ciertas sustancias tales como cafeína, creatina, hierro y CHO-proteína. Para el resto de los NS&EA estudiados, el uso fue similar entre los jugadores T100 y OT100. Finalmente, las diferencias en el uso de NS&EA entre grupos pudieran estar relacionadas con los diferentes profesionales escogidos para el asesoramiento nutricional en T100 vs. OT100.post-print691 K