Elliptic curves with torsion group Z/6Z\Z /6\Z

We exhibit several families of elliptic curves with torsion group isomorphic to $\Z/6\Z$ and generic rank at least $3$. Families of this kind have been constructed previously by several authors: Lecacheux, Kihara, Eroshkin and Woo. We mention the details of some of them and we add other examples developed more recently by Dujella and Peral, and MacLeod. Then we apply an algorithm of Gusi\'c and Tadi\'c and we find the exact rank over \Q(t) to be 3 and we also determine free generators of the Mordell-Weil group for each family. By suitable specializations, we obtain the known and new examples of curves over \Q with torsion $\Z/6\Z$ and rank $8$, which is the current record

Effect of electrochemical charging on the hydrogen embrittlement susceptibility of a low-alloyed tempered martensitic steel submitted to high internal pressure

The influence of hydrogen on the mechanical behavior of a quenched and tempered 42CrMo4 steel has been evaluated by means of high internal pressure fracture tests carried out on hydrogen precharged notched cylindrical specimens. The notched cylindrical specimens were precharged for 3 h time with 1.2 mA/cm2 in two different aqueous media: 1 M H2SO4 added with 0.25 g/l As2O3 and 3.5% of NaCl solution. Hydraulic fracture tests were performed at different ramps of pressure: 7000, 220, 80, 60 and 30 MPa/h, respectively. Hydrogen damage was more marked when the acid aqueous medium (1 M H2SO4 + 0.25 g/l As2O3) was employed. In this case, a higher hydrogen concentration was introduced, leading to hydrogen decohesion micromechanisms (HEDE) near the notched region, especially when tests were performed at 60 MPa/h. Hydrogen embrittlement susceptibility is discussed in terms of the microstructural singularities and the operative fracture micromechanisms observed in each case

Characterization of competing distortions in YFe2O4

We report the structural changes of three YFe2O4-δ (δ<0.1) specimens using high resolution synchrotron x-ray powder diffraction between 80 and 300 K. All samples adopt a rhombohedral cell at room temperature (space group R3m). This cell becomes unstable for the three samples on cooling, and the oxygen-poor specimen (δ∼0.1) shows a single transition at 240 K. The nearly stoichiometric (δ≤0.03) compounds exhibit two structural transitions with decreasing temperature at about 240 and 200 K. Each transition is revealed by an anomaly in the heat capacity measurements and a jump in the electric resistivity. Below 240 K, a strong splitting of some diffraction peaks is accompanied by the occurrence of superstructure peaks that follow the propagation vector k=(1/7,-2/7,9/7). The cell symmetry is then triclinic, and the structural transition is characterized by an expansion of the c axis coupled to a contraction of the other two lattice parameters. There are 49 nonequivalent sites for Fe atoms with a maximum charge disproportionation of ∼0.5e-. Upon cooling at 200 K, the previous superstructure peaks begin to vanish, and finally they are replaced by a new set of superstructure peaks following the propagation vector k=(1/4,1/2,1/4) with respect to the rhombohedral cell. The transition is also reflected in sudden changes in the lattice parameters that seem to smooth the changes observed in the previous transition. The new cell is also triclinic, and there are 48 nonequivalent Fe sites with a maximum charge disproportionation of ∼0.7e-. Both phases coexist in a wide temperature range because this second transition is not completed at 80 K. A symmetry mode analysis indicates a complicated pattern for the charge distribution in the Fe sublattice of both distorted structures but clearly discard any bimodal distribution of only two types of Fe cations. Therefore, the sharp jumps in the electric resistivity at the phase transitions are clearly correlated with two different structural changes. Finally, the oxygen stoichiometry seems to be a key factor in the stabilization of the different distorted structures.We are thankful for financial support from the Spanish Ministerio de Economía y Competitividad (MINECO) (Projects No. MAT2012-38213-C02-1-2 and No. MAT2015-68760-C2-1-2, cofunded by the European Regional Development Fund [ERDF] allocated by the European Union) and Diputacion General de Aragón (DGA, project E69).Peer Reviewe

CuentosIE: can a chatbot about “tales with a message” help to teach emotional intelligence?

In this article, we present CuentosIE (TalesEI: chatbot of tales with a message to develop Emotional Intelligence), an educational chatbot on emotions that also provides teachers and psychologists with a tool to monitor their students/patients through indicators and data compiled by CuentosIE. The use of “tales with a message” is justified by their simplicity and easy understanding, thanks to their moral or associated metaphors. The main contributions of CuentosIE are the selection, collection, and classification of a set of highly specialized tales, as well as the provision of tools (searching, reading comprehension, chatting, recommending, and classifying) that are useful for both educating users about emotions and monitoring their emotional development. The preliminary evaluation of the tool has obtained encouraging results, which provides an affirmative answer to the question posed in the title of the article.The research work conducted is part of the R&D projects “CORTEX: Conscious Text Generation” (PID2021-123956OB-I00), funded by MCIN/ AEI/10.13039/501100011033/ and the project “NL4DISMIS: Natural Language Technologies for dealing with dis- and misinformation with grant reference (CIPROM/2021/021)” funded by the Generalitat Valenciana. Furthermore, it has been funded by the BALLADEER project (PROMETEO/2021/088) from the Consellería Valenciana and by the AETHER-UA (PID2020-112540RB-C43) project from the Spanish Ministry of Science and Innovation

Dissolution and gettering of iron during contact co-firing

The dissolution and gettering of iron is studied during the final fabrication step of multicrystalline silicon solar cells, the co-firing step, through simulations and experiments. The post-processed interstitial iron concentration is simulated according to the as-grown concentration and distribution of iron within a silicon wafer, both in the presence and absence of the phosphorus emitter, and applying different time-temperature profiles for the firing step. The competing effects of dissolution and gettering during the short annealing process are found to be strongly dependant on the as-grown material quality. Furthermore, increasing the temperature of the firing process leads to a higher dissolution of iron, hardly compensated by the higher diffusivity of impurities. A new defect engineering tool is introduced, the extended co-firing, which could allow an enhanced gettering effect within a small additional tim

Family physicians' views on participating in prevention of major depression. The predictD-EVAL qualitative study

Background The predictD intervention, a multicomponent intervention delivered by family physicians (FPs), reduced the incidence of major depression by 21% versus the control group and was cost-effective. A qualitative methodology was proposed to identify the mechanisms of action of these complex interventions. Purpose To seek the opinions of these FPs on the potential successful components of the predictD intervention for the primary prevention of depression in primary care and to identify areas for improvement. Method Qualitative study with FPs who delivered the predictD intervention at 35 urban primary care centres in seven Spanish cities. Face-to-face semi-structured interviews adopting a phenomenological approach. The data was triangulated by three investigators using thematic analysis and respondent validation was carried out. Results Sixty-seven FPs were interviewed and they indicated strategies used to perform the predictD intervention, including specific communication skills such as empathy and the activation of patient resources. They perceived barriers such as lack of time and facilitators such as prior acquaintance with patients. FPs recognized the positive consequences of the intervention for FPs, patients and the doctor-patient relationship. They also identified strategies for future versions and implementations of the predictD intervention. Conclusions The FPs who carried out the predictD intervention identified factors potentially associated with successful prevention using this program and others that could be improved. Their opinions about the predictD intervention will enable development of a more effective and acceptable version and its implementation in different primary health care settings

Brazilian Buffalo Genetic Variability by Cross-Specific Microsatellite Set

Buffaloes (Bubalus bubalis) are widely distributed and were introduced to Brazil in 1895. Most of the molecular genetic characterization of buffaloes has been done with cross-specific (cattle) markers, but few of them include Brazilian populations. Nineteen commonly used cattle microsatellites were tested to develop a multiplexed set of microsatellites and characterize Brazilian buffalo. Three PCR mixes were finally developed with the 11 markers that succeed in amplify and were polymorphic (58%). The average number of alleles was 5.42, with an average observed and expected heterocigozity of 0.441 and 0.695, respectively. As it was expected, Brazilian buffalo variability was lower than the previously reported from the domestication centres (China and India), but higher than the seriously selected European populations. The exclusion power calculated for the eleven markers in Brazilian buffalo was 0.9999999996, this allows its use in DNA based traceability.Instituto de Genética Veterinari