Molecular Dynamics Simulations of Lead and Lithium in Liquid Phase

Pb17Li is today a reference breeder material in diverse fusion R&D programs worldwide. Extracting dynamic and structural properties of liquid LiPb mixtures via molecular dynamics simulations, represent a crucial step for multiscale modeling efforts in order to understand the suitability of this compound for future Nuclear Fusion technologies. At present a Li-Pb cross potential is not available in the literature. Here we present our first results on the validation of two semi-empirical potentials for Li and Pb in liquid phase. Our results represent the establishment of a solid base as a previous but crucial step to implement a LiPb cross potential. Structural and thermodynamical analyses confirm that the implemented potentials for Li and Pb are realistic to simulate both elements in the liquid phase

The effects of over-indebtedness on individual health

This paper uses data from the 2002-2005-2008 waves of the Spanish Survey of Household Finances (EFF) to investigate whether debts burdens hamper people's health. Several measures of debt strain are constructed, including debt-to-income ratios, the existence of debt arrears and amounts of outstanding debts. The paper also differentiates between mortgage and non-mortgage debts and explores the role of social norm effects in the debt-health relationship. The results, based on a random effects model extended to include a Mundlak term, show that nonmortgage debt payments and debt arrears affect significantly people's health. Furthermore, mild social norm effects are detected, according to which being less indebted than the reference group results, ceteris paribus, in better health

Machine Learning for Screening Large Organic Molecules

Organic semiconductors are promising materials for cheap, scalable and sustainable electronics, light-emitting diodes and photovoltaics. For organic photovoltaic cells, it is a challenge to find compounds with suitable properties in the vast chemical compound space. For example, the ionization energy should fit to the optical spectrum of sun light, and the energy levels must allow efficient charge transport. Here, a machine-learning model is developed for rapidly and accurately estimating the HOMO and LUMO energies of a given molecular structure. It is build upon the SchNet model (Sch\"utt et al. (2018)) and augmented with a `Set2Set' readout module (Vinyals et al. (2016)). The Set2Set module has more expressive power than sum and average aggregation and is more suitable for the complex quantities under consideration. Most previous models have been trained and evaluated on rather small molecules. Therefore, the second contribution is extending the scope of machine-learning methods by adding also larger molecules from other sources and establishing a consistent train/validation/test split. As a third contribution, we make a multitask ansatz to resolve the problem of different sources coming at different levels of theory. All three contributions in conjunction bring the accuracy of the model close to chemical accuracy.Comment: Presented at E-MRS Fall Meeting 2022, Symposium

Does income deprivation affect people's mental well-being?

Incluye bibliografíaEste trabajo utiliza datos de panel de olas 2002-2010 del Panel Socioeconómico Alemán, a fin de evaluar el impacto que la privación en términos de renta familiar tiene sobre el bienestar mental. La heterogeneidad no observable está controlada a través de un modelo de efectos aleatorios que incluye un término de Mundlak y controles explícitos para la personalidad de los individuos. El artículo muestra que, dada una renta familiar, una posición menos favorable en la posición relativa de la distribución de renta se traduce en un menor bienestar mental. Este efecto no es estadísticamente significativo entre las mujeres. Sin embargo, en el caso de los hombres el efecto perjudicial que un aumento de una desviación estándar en la privación de renta tiene sobre el bienestar mental equivale a un pérdida del 30% en la renta familiar permanente. Curiosamente, este impacto difiere entre individuos dotados con diferentes habilidades no cognitivas. Estos resultados sugieren que las políticas, prácticas e iniciativas orientadas a mejorar el bienestar de los ciudadanos europeos requieren una mayor consideración de la renta relativa de los individuosThis paper uses panel data from the 2002-2010 waves of the German Socio-Economic Panel dataset (SOEP) to assess the impact of income deprivation upon individual mental well-being. Unobserved heterogeneity is controlled for by means of a random effects model extended to include a Mundlak term and explicit controls for the respondents’ personality traits. The paper shows that, for a given household income, a less favourable relative position in the income distribution is associated with lower mental well-being. This effect is not statistically significant among women, though. Among men, a one standard deviation increase in income deprivation is found to be as harmful as a reduction in permanent household income of almost 30%. Interestingly, this impact is found to differ among individuals endowed with different sets of non-cognitive skills. We suggest that policies, practices and initiatives aimed at improving well-being among European citizens require a better understanding of individuals’ sensitiveness to others’ incom