Improving the family orientation process in Cuban Special Schools trough Nearest Prototype classification

Cuban Schools for children with Affective – Behavioral Maladies (SABM) have as goal to accomplish a major change in children behavior, to insert them effectively into society. One of the key elements in this objective is to give an adequate orientation to the children’s families; due to the family is one of the most important educational contexts in which the children will develop their personality. The family orientation process in SABM involves clustering and classification of mixed type data with non-symmetric similarity functions. To improve this process, this paper includes some novel characteristics in clustering and prototype selection. The proposed approach uses a hierarchical clustering based on compact sets, making it suitable for dealing with non-symmetric similarity functions, as well as with mixed and incomplete data. The proposal obtains very good results on the SABM data, and over repository databases

Towards an HH-theorem for granular gases

The $H$-theorem, originally derived at the level of Boltzmann non-linear kinetic equation for a dilute gas undergoing elastic collisions, strongly constrains the velocity distribution of the gas to evolve irreversibly towards equilibrium. As such, the theorem could not be generalized to account for dissipative systems: the conservative nature of collisions is an essential ingredient in the standard derivation. For a dissipative gas of grains, we construct here a simple functional $\mathcal H$ related to the original $H$, that can be qualified as a Lyapunov functional. It is positive, and results backed by three independent simulation approaches (a deterministic spectral method, the stochastic Direct Simulation Monte Carlo technique, and Molecular Dynamics) indicate that it is also non-increasing. Both driven and unforced cases are investigated

Laser floating zone growth of Yb, or Nd, doped (Lu0.3Gd0.7)2SiO5 oxyorthosilicate single-crystal rods with efficient laser performance

Disordered crystals are being presently developed to enlarge the fluorescence bandwidth of trivalent lanthanides incorporated for generation of ultrashort (femtosecond) laser pulses in mode-locked oscillators and amplifiers, but crystal disorder induces a reduction of thermal conductivity which hampers the uniform crystal cooling after growth, leading to internal stresses. This is particularly remarkable when using the Laser Floating Zone (LFZ) growth technique; thus so far laser operation has been obtained only for LFZ-grown crystals with high thermal conductivity (κ ≥ 10 W m−1 °C−1) but without disorder, i.e. YAG, Y2O3 or REVO4. To overcome this limitation we present the LFZ growth of (Lu0.351Gd0.630Yb0.019)2SiO5 and (Lu0.307Gd0.612Nd0.081)2SiO5 refractory (melting point ≈ 1950 °C) oxyorthosilicate single-crystal rods with dimensions suitable for high power diode laser pumping, despite these crystals having medium/low thermal conductivity, κ < 4 W m−1 °C−1. Rods with ≈10 mm length and ≈1.75 mm diameter were grown in air under a CO2 laser at 10 mm h−1. X-ray diffraction analyses confirm the monoclinic C2/c structure of the obtained crystals. For the chosen ≈0.3Lu/0.7Gd ratio some of the crystals are transparent and free of macro-defects. The continuous wave laser performance of Yb3+ and Nd3+ incorporated ions is demonstrated under Ti-sapphire laser pumping in an astigmatism compensated Z-shaped optical cavity. The laser performance of these LFZ oxyorthosilicates is found to be comparable to that reported in Czochralski (Cz) grown crystals. The faster pulling rate (almost one order of magnitude larger for LFZ than for Cz), the high crystal composition purity, and the absence of crucible or atmosphere control make the LFZ technique a low cost alternative for the present needs of diode laser pumped mode-locked medium/high power laser oscillators.This work is funded by FEDER funds (COMPETE 2020 Programme), by national funds through FCT – Portuguese Foundation for Science and Technology (UID/CTM/50025/2019) as well as by Ministerio de Ciencia Innovación y Universidades (RTI2018-094859-B-I00, also FEDER co-fund) of Spain. F. Rey-García acknowledges European Union (H2020-FET-OPEN/0426), Xunta de Galicia (ED431E 2018/08) and FCT (SFRH/BPD/108581/2015) projects.Peer reviewe

Laser Floating Zone: General Overview Focusing on the Oxyorthosilicates Growth

This chapter reviews the laser floating zone (LFZ) technique, also known as the laser-heated pedestal growth (LHPG), focusing on the recently produced rare-earth-doped oxyorthosilicate fibers. LFZ has been revealed as a suitable prototyping technique since high-quality crystals can be developed in short time with low consumption of precursor materials in a crucible-free processing that ensures to practically avoid by-products. Moreover, additional advantages are the possibility to treat and melt highly refractory materials together with the easy way for tailoring the final microstructural characteristics and this way the macroscopic physical properties. Thus, refractory rare-earth (RE) doped oxyorthosilicates following the formula RE2SiO5 have been recently produced by the LFZ technique for tuning laser emission parameters. The oxyorthosilicates have high chemical stability and allow incorporation of many rare-earth ions yielding different applications, such as laser host materials, gamma ray detectors or scintillators, environmental barrier coatings (EBCs) and waveguides, among others. Thus, different kinds of oxyorthosilicates were produced by the LFZ technique, and the detailed effects of the main processing parameters on crystal’s characteristics are discussed in this chapter

A Multiinstitutional Spanish Master’s Program in Ecosystem Restoration: Vision and Four-Year Experience

Since 2006, an innovative, multiinstitutional Spanish Master in Ecosystem Restoration (MER) is jointly offered by four major public universities in Madrid. In view of the high student demand—about 900 applications this academic year for only 30 places, a remarkable 75% rate of professional poststudy employment in a period of economic crisis, and the high number (> 40) of prestigious organizations involved in the program, we consider the MER program, although still young, to be very promising for the long term. We explain the process to create the MER and achieve the results obtained thus far. We describe its organization, report its vital statistics in terms of students, and identify some strengths and weaknesses observed to date. The MER program has evolved as a network of knowledge and experience that links universities, lecturers, researchers, students, private and public companies, NGOs, and administration centers. Our aim is to help other groups that may want to launch similar graduate-level ecological restoration degree programs

Soil P and cation availability and crop uptake in a forage rotation under conventional and reduced tillage

Long-term conservation tillage can modify vertical distribution of nutrients in soil profiles and alter nutrient availability and yields of crops

Landscape- and field-scale control of spatial variation of soil properties in Mediterranean montane meadows

Las figuras que contiene el documento se localizan al final del mismoSoil properties of terrestrial ecosystems are controlled by a variety of factors that operate at different scales. We tested the role of abiotic and biotic factors that potentially influence spatial gradients of total ion content, acidity, carbon, total nitrogen, and total phosphorous in topsoil. We studied a network of Mediterranean montane meadows that spans a 2000-m altitudinal gradient. The analyzed factors were grouped into two spatial scales: a landscape scale (climate and land form) and a field scale (topography, soil texture, soil moisture, and plant community composition). Total ion content and acidity are the major and independent variation trends of soil geochemistry. Soil acidity, carbon, and nitrogen increased along the altitudinal gradient whereas there was no relationship between total ion content and phosphorous and elevation. Climate had no direct influence on the analyzed gradients; all effects of climate were indirect through plant community composition and/or soil moisture. The results point to three types of models that explain the gradients of soil chemical composition: (1) a predominantly biotic control of carbon and nitrogen, (2) a predominantly abiotic control of acidity, and (3) a combined biotic and abiotic control of total ionic content. No direct or indirect effects explained the gradient of phosphorous. In our study region (central Spain), climate is predicted to turn more arid and soils will lose moisture. According to our models, this will result in less acid and fertile soils, and any change in plant community composition will modify gradients of soil carbon, nitrogen, total ion content, and acidity

Efectos de varios factores ambientales sobre las tasas de descomposición en encinares mediterráneos

Resumen de una presentación realizada en: I Simposio sobre Interacciones Planta-Suelo (ICA-CSIC, Madrid, 25-26 Febrero 2016)[ES] Los encinares son ecosistemas de gran valor que están sufriendo un proceso de decaimiento, lo que puede afectar a su capacidad para almacenar carbono. Se plantea este proyecto de tesis para estudiar el efecto del decaimiento de encinares sobre las tasas de descomposición de la hojarasca, las raíces y las herbáceas, y los factores medioambientales que la controlan. Los factores que se pretende estudiar son: la calidad de la materia en descomposición, el clima, la fotodegradación, y el efecto de diferentes conjuntos de fauna del suelo. El efecto de dichos factores sobre la descomposición se analizará a través de 4 experimentos con bolsas de descomposición. Experimento 1: Efecto del clima, de la fotodegradación y de la calidad de la hojarasca sobre las tasas de descomposición. Se ha diseñado un experimento factorial para el seguimiento de las tasas de descomposición de herbáceas y de hojas y raíces de encinas, situando bolsas en 8 encinares afectados distribuidos por el territorio peninsular español. Experimento 2: Efecto de la microfauna, la mesofauna y la macrofauna del suelo sobre los procesos de descomposición de hojarasca. Se estudiará mediante tratamientos de exclusión de fauna del suelo. Experimento 3: Efecto interactivo de la temperatura, precipitación y radiación solar sobre la descomposición de hojarasca. Se utilizarán mesocosmos para someter bolsas de hojarasca de herbáceas a dos niveles para cada uno de esos tres factores, con todas las interacciones entre ellos. Experimento 4: Contribución de diferentes procesos abióticos (fotodegradación y degradación térmica), bióticos (descomposición microbiana) así como su interacción en la descomposición de la materia orgánica. Se realizará con herbáceas bajo condiciones controladas de laboratorio. Estos experimentos permitirán describir de una manera mecanicista un proceso tan relevante para las interacciones planta-suelo como es la descomposición así como los factores medioambientales que la controlan.Peer reviewe

Extended description of tunnel junctions for distributed modeling of concentrator multi-junction solar cells

One of the key components of highly efficient multi-junction concentrator solar cells is the tunnel junction interconnection. In this paper, an improved 3D distributed model is presented that considers real operation regimes in a tunnel junction. This advanced model is able to accurately simulate the operation of the solar cell at high concentraions at which the photogenerated current surpasses the peak current of the tunnel junctionl Simulations of dual-junction solar cells were carried out with the improved model to illustrate its capabilities and the results have been correlated with experimental data reported in the literature. These simulations show that under certain circumstances, the solar cells short circuit current may be slightly higher than the tunnel junction peak current without showing the characteristic dip in the J-V curve. This behavior is caused by the lateral current spreading toward dark regions, which occurs through the anode/p-barrier of the tunnel junction