Quantum computing and materials science: A practical guide to applying quantum annealing to the configurational analysis of materials

Using quantum computers for computational chemistry and materials science will enable us to tackle problems that are intractable on classical computers. In this paper, we show how the relative energy of defective graphene structures can be calculated by using a quantum annealer. This simple system is used to guide the reader through the steps needed to translate a chemical structure (a set of atoms) and energy model to a representation that can be implemented on quantum annealers (a set of qubits). We discuss in detail how different energy contributions can be included in the model and what their effect is on the final result. The code used to run the simulation on D-Wave quantum annealers is made available as a Jupyter Notebook. This Tutorial was designed to be a quick-start guide for the computational chemists interested in running their first quantum annealing simulations. The methodology outlined in this paper represents the foundation for simulating more complex systems, such as solid solutions and disordered systems

Las políticas del retorno y el discurso político sobre el exilio en la democracia argentina : encuentros y desencuentros del nos-otros

La migración política, a la que se suele identificar con el término exilio, cobra protagonismo como campo de estudio en Argentina a partir de los exiliados de la última dictadura militar. La democracia movilizó el retorno; pero también la decisión de permanecer en el país de destino. Los que retornaron se convirtieron en repatriados; los que se quedaron en la sociedad de refugio, en migrantes. En estas idas y venidas, la repatriación fue consecuencia de una serie de medidas tanto del Estado argentino como de organismos internacionales. El retorno de los exiliados visibilizó un espacio narrativo de encuentros y desencuentros sobre el exilio, generado por un discurso político en pro de políticas de reparación y apoyo para el retorno frente a representaciones maniqueas que dividían a las víctimas de la última dictadura militar en dos grupos: “los que se fueron" y “los que se quedaron". Esta fricción interna ha hecho que el discurso político se mueva de un modo ambiguo a la hora de llevar a la agenda del debate democrático el reconocimiento de los exiliados como víctimas de los violentos sucesos acaecidos en nuestro país durante la década de 1970 hasta la caída de la dictadura militar. Se entiende que el exilio y el retorno son fenómenos sociales que entrelazan sentidos colectivos e individuales en una pluralidad de experiencias y de identidades políticas que involucran a los exiliados y a sus hijos/as. Nuestro objetivo en este trabajo, de carácter exploratorio, es incursionar en proyectos concretos y en las diferencias políticas que propiciaron o no el retorno y que nos obligan a repensar el lugar de los exiliados y de sus hijos/as en la Argentina. Nos interesa realizar un rastreo histórico que permita descubrir la dimensión política y el impacto del exilio-retorno desde el regreso de democracia hasta la actualidad.Fil: García Vázquez, Cristina B.. Universidad Nacional del ComahueFil: Camino Vela, Francisco. Universidad Nacional del ComahueFil: Schierloh, Melina. Universidad Nacional del Comahu

Quantum computing and materials science: A practical guide to applying quantum annealing to the configurational analysis of materials

Using quantum computers for computational chemistry and materials science will enable us to tackle problems that are intractable on classical computers. In this paper, we show how the relative energy of defective graphene structures can be calculated by using a quantum annealer. This simple system is used to guide the reader through the steps needed to translate a chemical structure (a set of atoms) and energy model to a representation that can be implemented on quantum annealers (a set of qubits). We discuss in detail how different energy contributions can be included in the model and what their effect is on the final result. The code used to run the simulation on D-Wave quantum annealers is made available as a Jupyter Notebook. This Tutorial was designed to be a quick-start guide for the computational chemists interested in running their first quantum annealing simulations. The methodology outlined in this paper represents the foundation for simulating more complex systems, such as solid solutions and disordered systems

Saturated hydrocarbon content in olive fruits and crude olive pomace oils

40 Páginas; 14 Tablas; 5 FigurasOlive fruits contain an n-alkane series of saturated hydrocarbons mainly in the pulp. Lower amounts of a complex mixture of paraffins, unresolved by gas chromatography (UCM – unresolved complex mixture), have been found in cuticle, stone (woody shell and seed), olive leaves, and talc used as an aid to olive oil extraction. The amounts of both kinds of hydrocarbons are related to the olive cultivar and are transferred to oils in a proportion depending on the oil-obtaining process (centrifugation or solvent extraction). In olive oil obtained by centrifugation, only n-alkanes were detected. However, in olive oil extracted by second centrifugation, small amounts of UCM paraffins were detected together with the n-alkanes. Olive pomace oils showed a very variable content of both types of hydrocarbons according to the different obtaining process, such as double centrifugation, solvent extraction or centrifugation followed by solvent extraction. ‘White mineral oil’ used in oil extraction machinery is the source of the high concentrations of UCM paraffins found in some olive and olive pomace oils. In the case of second centrifugation olive oil, a maximum limit of 50 mg kg−1 of UCM is suggested, whereas in the case of crude olive pomace oil, it amounts to 250 mg kg−1 plus an additional minimum of 1.0 for the n-alkanes/UCM ratio.The technical expertise of Mrs Rosario González Cordones is acknowledged for her assistance in the laboratory. This work was supported by a grant of the Spanish Ministry of Agriculture, Food, and EnvironmentPeer reviewe

The `s-rule' exclusion principle and vacuum interpolation in worldvolume dynamics

We show how the worldvolume realization of the Hanany-Witten effect for a supersymmetric D5-brane in a D3 background also provides a classical realization of the `s-rule' exclusion principle. Despite the supersymmetry, the force on the D5-brane vanishes only in the D5 `ground state', which is shown to interpolate between 6-dimensional Minkowski space and an $OSp(4^*|4)$-invariant $adS_2\times S^4$ geometry. The M-theory analogue of these results is briefly discussed.Comment: 25 pages, 9 figures, LaTeX JHEP styl

Sago Palm Flour Weight in Different Environmental Conditions: A Mathematical Model

For the past decades, the demand for starch from the sago palm (Metroxylon sagu Rottb.) from the starch industry is increasing because of the palm’s high starch yield and low cost of production. This study presented a model which illustrates the relationship of sago palm flour weight with respect to its age depending on sago palm environmental condition (i.e., dry, wet, or submerged). Five different growth models were considered in this study, namely, the quadratic, cubic, quartic, power, and logarithmic models, which were ran using a metaheuristic approach, specifically genetic algorithm (GA), in order to estimate the weights associated with the independent variable age and to generate an estimate for the dependent variable flour weight. GA performance was measured using sum of squared residuals (SSR) as the fitness function while the accuracy of the models were measured using the mean absolute percentage error (MAPE). The results show that the best fit model models for dry, wet, and submerged environmental conditions are cubic, cubic, and quartic models, respectively. The best fit models generated SSR values closer to the tolerance value of 0.000001 and have MAPE values of 2.820, 1.366, and 4.316, respectively, which indicate high accuracy. These models will help aide potential investors or land owners to identify the maximum potential starch yield of sago palm in areas where data with respect to growth stages are only available

Starch Yield Based on Physical Dimensions and Age of Sago Palm: A Mathematical Model

This study employed firefly algorithm (FA) to generate a mathematical model of sago palm’s potential starch yield based on the physical dimensions, namely, diameter breast height (DBH), palm height, and age. Three environmental conditions (i.e., dry, wet, and submerged) were taken into consideration in the modelling process using the general linear and nonlinear models. Moreover, the resulting models were assessed using sum of squared residuals (SSR) as FA’s fitness function and mean absolute percentage error (MAPE) for the models’ accuracy. Results show that general linear models are the best fit models for the sago palms growing in the three different environmental conditions with respect to the considered parameters. These models were used to quantitatively describe the underlying relationships between the starch yield with respect to the physical dimensions and age in order to determine the maximum potential starch yield of sago palm for the different environmental conditions. The models estimate that the maximum potential starch yield for dry, wet, and submerged environmental conditions are as follows: 0.75 m, 0.35 m, and 0.75 m for DBH, respectively; 10.5 m for palm height for all three; and 11.5 years, 15.5 years, and 15.5 years for age, respectively. These results will be able to aid farmers and potential investors in maximizing their sago starch produce. This will also help them as a guide for identifying harvestable sago palms which can be incorporated in their harvest plan