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The optimization and advanced study of a laser-plasma electron injector are presented based on a truncated ionization injection scheme for high quality beam production. The smilei code is used with laser envelope approximation and a low number of particles per cell to reach computation time performances enabling the production of a large number of accelerator configurations. The developed and tested workflow is a possible approach for the production of a large dataset for laser-plasma accelerator optimization. A selection of functions of merit used to grade generated electron beams is discussed. Among the significant number of configurations, two specific working points are presented in detail. All data generated are left open to the scientific community for further study and optimization.

Introduction The use of internet among children and adolescent has risen in the last decade. In addition, suicide is the second cause of death among adolescents. Previous research have indicated the relation between Problematic Internet Use (PIU) and different mental health problems. Nonetheless there is a lack of studies analyzing the relation between suicide behaviour and PIU Objectives The main objective of the present work was to analyze the relation between Problematic Internet Use and suicide behaviour and depression in adolescents Methods A total of 1036 adolescents (450 males) were randomly selected. Mean age was 15,21 (SD = 1,23). The Adolescent Behavioural Suicide Scale SENTIA, The Reynolds Adolescent Depression Scale Short Form (RADS-SF), and The Compulsive Internet Use Scale (CIUS) were used. A Manova was performed with two groups (risk and non-risk to PIU) as independent variables and suicide and depression scores as dependent variables Results The results revealed a statiscally signifficant association between PIU and both depression and suicide behaviour (λ = 0.245, F(2,81,000) = 15.549, P ≤ 0.001, η² = 0.116). In particular, adolescents at a higher risk for PIU obtained higher scores on suicide behaviours and depression. Conclusions Results found in the present study reveal that adolescents have moderate prevalence rates for PIU. Also adolescents at risk for PIU with a total of more than 3 hour sof internet use everyday were at a higher risk for suicide. Prevention strategies should be devote to intervene in internet use as it maybe a variable affecting suicide behaviour. Disclosure No significant relationships.

Iron oxide nanostructures are promising materials for photoelectrochemical applications such as water splitting. In this work, electrochemical anodization of iron is used to form different iron oxide nanostructures, and the influence of different anodization parameters was studied in order to find the most suitable nanostructure for photocatalysis applications. On the one hand, hydrodynamic conditions were evaluated by stirring the electrode at different rotation speeds during the electrochemical anodization to check their influence on the formation of the nanostructures. On the other hand, different heating rates during the annealing treatment were studied for obtaining efficient iron oxide nanostructures. The synthesized nanostructures were characterized by different techniques such as photocurrent density vs. potential measurements, Field Emission Scanning Electron Microscopy, Raman spectroscopy and Incident Photon-to-electron Conversion Efficiency (IPCE). The results revealed that the best heating rate during the annealing treatment is 15 °C·min-1 and that the hydrodynamic conditions allow the formation of nanotubular iron oxide structures achieving ~0.1 mA·cm-2 at 0.5 V (vs. Ag/AgCl) in the water splitting measurements. Moreover, all the nanostructures are mainly composed by hematite (a-Fe2O3) with some amount of magnetite (Fe3O4) in their structure. Finally, the IPCE measurements showed that the best rotation speed during the electrochemical anodization for the formation of an efficient iron oxide nanostructure for photocatalysis applications is 1,000 rpm.

Nowadays, hematite (a-Fe2O3) has emerged as a promising photocatalyst for efficient degradation of organic pollutants due to its properties such as suitable band-gap (~2.1 eV), stability against photocorrosion, abundance and low cost. However, some drawbacks such as low carrier mobility and short hole diffusion length limit its efficiency. In order to overcome these issues, self-ordered nanotubes can be synthetized. Anodization is one of the simplest and most economic techniques to produce nanostructures with high control. In the present study, self-ordered hematite nanotubes were synthetized by two-step electrochemical anodization. In two-step anodization, a first-step was actually a pretreatment to form well-ordered nanoporous template in which well-ordered nanotubes are grown by a second-step. The formed nanotubes were characterized by different methods such as Field Emission Scanning Microscopy and Raman spectroscopy to determine their morphology and crystalline structure, respectively. Furthermore, the obtained nanotubes were characterized by means of photocurrent density versus potential measurements (water splitting) to evaluate their efficiency as photocatalyst. Good results were obtained as the achieved photocurrent density was 0.079mA cm-2 at 0.58 V (vs. Ag/AgCl), which indicates that the nanotubes synthetized by two-step anodization aresuitable photocatalysts for degradation of organic pollutants.