Características del alpechín: modelos y análisis estadístico

A synthesis of the work carried out on Olive Mill Wastewater (OMW) characterisation is given, covering articles published over the last 50 years. Data on OMW characterisation found in the literature are summarised and correlations between them and with phenolic compounds content are sought. This permits the characteristics of an OMW to be estimated from one simple measurement: the phenolic compounds concentration. A model based on OMW characterisations accounting 6 countries was developed along with a model for Portuguese OMW. The statistical analysis of the correlations obtained indicates that Chemical Oxygen Demand of a given OMW is a second-degree polynomial function of its phenolic compounds concentration. Tests to evaluate the regressions significance were carried out, based on multivariable ANOVA analysis, on visual standardised residuals distribution and their means for confidence levels of 95 and 99 %, validating clearly these models. This modelling work will help in the future planning, operation and monitoring of an OMW treatment plant.Presentamos una síntesis de los trabajos realizados en los últimos 50 años relacionados con la caracterización del alpechín. Realizamos una recopilación de los datos publicados, buscando correlaciones entre los datos relativos al alpechín y los compuestos fenólicos. Esto permite la determinación de las características del alpechín a partir de una sola medida: La concentración de compuestos fenólicos. Proponemos dos modelos, uno basado en datos relativos a seis países y un segundo aplicado únicamente a Portugal. El análisis estadístico de las correlaciones obtenidas indica que la demanda química de oxígeno de un determinado alpechín es una función polinómica de segundo grado de su concentración de compuestos fenólicos. Se comprobó la significancia de esta correlación mediante la aplicación del análisis multivariable ANOVA, y además se evaluó la distribución de residuos y sus promedios a un nivel de fiabilidad del 95 y 99 %. Este trabajo ayudará al diseño futuro de plantas de tratamiento de alpechín, así como a su funcionamiento y control

Energy densities in the strong-interaction limit of density functional theory

We discuss energy densities in the strong-interaction limit of density functional theory, deriving an exact expression within the definition (gauge) of the electrostatic potential of the exchange-correlation hole. Exact results for small atoms and small model quantum dots are compared with available approximations defined in the same gauge. The idea of a local interpolation along the adiabatic connection is discussed, comparing the energy densities of the Kohn-Sham, the physical, and the strong-interacting systems. We also use our results to analyze the local version of the Lieb-Oxford bound, widely used in the construction of approximate exchange-correlation functionals.Comment: 12 page

A demonstration circuit to support e-learning on IEEE 1149.1/4 infrastructures

Teaching electronics in engineering encompasses several issues related to the specific technical subjects and the educational model considered. The first embraces a set of specific scientific concepts while the second usually includes a big number of laboratorial classes. Electronic design usually includes analog and digital components that are developed using different technologies, an analog device usually consisting of the association of different components, while a digital device is nowadays designed using hardware programming languages. In any case, circuit design should include the intended mission circuit but also additional circuitry in order to support debug and test operations. The additional functionalities included for this purpose assume special importance during the circuit prototype validation phase. The most common errors result from the use of programmable and configurable devices (e.g. microcontrollers, FPGA) although those resulting from analogue components are usually harder to diagnosis and correct. A structured way to face those issues is the use of IEEE1149.1/4 test infrastructures. Laboratorial classes on advanced subjects like this are one of the reasons why electronics is an expensive engineering education. Remote labs are presently being advertised as a mean to make the educational model more cost effective. Part of the laboratorial classes can be performed autonomously by the student, using remote circuits to verify if the developed code matches the intended result. Furthermore, as the remote laboratories are intrinsically based on ICT, it is easy to produce and use students' knowledge information to optimize the educational model. This document presents part of an IEEE1149.1/4 remote access educational platform for use on electronics courses.info:eu-repo/semantics/publishedVersio