Phase Separation Driven by External Fluctuations

The influence of external fluctuations in phase separation processes is analysed. These fluctuations arise from random variations of an external control parameter. A linear stability analysis of the homogeneous state shows that phase separation dynamics can be induced by external noise. The spatial structure of the noise is found to have a relevant role in this phenomenon. Numerical simulations confirm these results. A comparison with order-disorder noise induced phase transitions is also made.Comment: 4 pages, 4 Postscript figures included in text. LaTeX (with Revtex macros

Natural coagulants: analysis of potential use for drinking water treatment in developed and developing countries

[EN] Drinking water must be colorless, odorless and tasteless, and free of substances or micro-organisms that can cause disease. The process to obtain drinking water is purification, understood as the treatment to make water suitable for human consumption. Water purification is traditionally composed of a sequence of standard treatments including coagulation-flocculation, sedimentation, filtration, and disinfection. Some compounds named coagulants are used for coagulation-flocculation, which is the stage in which the suspended matter is removed and the water is clarified. Coagulants are usually synthetic, therefore represent a high cost and are difficult to gets in some areas, especially in developing countries. In addition, their use is being revised and restricted in different international standards, in order to control or prohibit its use because of the possible hazard effects that the remains of these products in treated water can cause to people. In contrast to synthetic coagulants, there are several natural compounds with coagulation properties which have some advantages such as easy availability and safety. At present, scientific community is paying more attention to natural coagulants as legal restrictions to synthetic ones are becoming more severe. This paper is a review of natural coagulants as an alternative to chemical coagulants, in which their potential application in the treatment of drinking water is analysed.García-Fayos, B.; Arnal Arnal, JM.; Sancho, M. (2018). Natural coagulants: analysis of potential use for drinking water treatment in developed and developing countries. Desalination and Water Treatment. 103:307-314. https://doi.org/10.5004/dwt.2018.22005S30731410

Tracking of learning level on design and safety skills in two core subjects of the chemical engineering degree at UPV

[EN] Chemical engineers develop their profession in areas in which design of processes and safety of installations, equipment and procedures designed are especially relevant due to the impact and consequences that a failure of these items represent. Therefore, curriculum of chemical engineers chemical engineering should include these disciplines as a valuable skill. In the Universitat Politècnica of València (UPV), design and safety competence training is worked in the curriculum of chemical engineering degree through several subjects. "Experimentation in Chemical Engineering III" (EIq3) from 3rd course, semester B and "Industrial Processes of Chemical Engineering" (PIIQ) from 4th course semester A, are core courses specially focussed on the development of several activities to work these skills. In EIq3 students design a production process to obtain oil from almond for cosmetic purposes. This design project includes: lab work to study and understand the stages of the production process and its performance, drawing of block and flow diagram of the process by using Autocad and recommendation of basic safety measures in the installation. In the following semester, students of PIIQ study different production processes and design a process to obtain olive oil. This design includes drawing of block and flow diagram of the full process, selection and justification of safety measures needed and its implementation in the installation through its drawing in the flow diagram. Safety is also strengthened through an activity of safety presentation about an item related to the installation that students should prepare and defense. This work collects and analyses the evolution of the learning level and its deepness into safety and design skills through the analysis of the results obtained along the several control points stablished in EIq3 and PIIQ courses. These control points are: deliverables of academic works at the beginning of EIq3, assessment of design project and written exam at the end of EIq3 and academic results at the end of PIIQ of several academic years. Progressive work along these two consecutive courses in safety and design skills have allowed to obtain a deeper degree of learning in these disciplines and better results in a medium term compared with the previous academic years in which these activities and methodology were not performed in both subjects.García-Fayos, B.; Sancho, M.; Arnal Arnal, JM. (2019). Tracking of learning level on design and safety skills in two core subjects of the chemical engineering degree at UPV. IATED. 6484-6491. https://doi.org/10.21125/inted.2019.1571S6484649

Development of a rubric for the evaluation of "design and project" competence in an experimental subject of chemical engineering degree

[EN] "Experimentation in Chemical Engineering III" is the last experimental core course of the Chemical Engineering Degree at the Universitat Politècnica València (UPV). It is a practical course of 4.5 ECTS which is taught in the 2nd semester of the 3rd year, in which students perform experimental sessions related to the subject "Separation Processes¿ taught in the previous semester. The subject has to work the competence "Design and Project", both in its specific and transversal approach. In order to develop suitably such competence, in 2016 it was requested an ¿Innovation and Education Improvement Project¿ (PIME), through the Institute of Education Sciences of the UPV, with the aim of integrate the Project Oriented Learning (POL) as the main methodology. The Project was implemented during the academic year 2017-2018 and the main objective was to perform experimental sessions to obtain data that would be used in the design project. Transition to POL methodology implied the design and development of new activities [1] and a change in the way that the evaluation was performed. The design project was the main learning product obtained and it is used to assess the development of the ¿Design and project¿ competence in the students. The tool used to evaluate the design project is a rubric. Rubric includes the evaluation criteria and their different levels of achievement and scoring, and allows a more homogeneous assessment by all the lecturers that evaluate the project. This paper describes the development process of the rubric and presents the final version which is currently used in the subject after two years of implementation that includes several changes made. This work will also describe the way that score of each item contributes to the final grade of the project and of the competence. The rubric presented can be applied to other subjects in which similar design projects would be performed, after adapting it to the particular context of each subject.Sancho, M.; García-Fayos, B.; Arnal Arnal, JM. (2019). Development of a rubric for the evaluation of "design and project" competence in an experimental subject of chemical engineering degree. IATED. 6395-6403. https://doi.org/10.21125/inted.2019.1552S6395640

Application of ultrafiltration for drinking water production in decentralised systems: 20 years of the AQUAPOT project

[EN] Access to drinking water is a basic human right which has become an international goal. However, despite the efforts made in the framework of the Millennium Development Goals of the United Nations, about 700 million people are still without access to an adequate source of drinking water in rural areas of developing countries, especially in Africa Sub-Saharan. The AQUAPOT project, developed by the "Instituto Universitario de Seguridad, Radiofisica y Medioambiental (ISIRYM)" of the "Universitat Politecnica de Valencia (UPV)", both in Spain, has been focused research on the design, development and installation of decentralised drinking water systems as an alternative to existing water management systems in developing areas. AQUAPOT systems are based on ultrafiltration technology and have been successfully applied in different localities in Ecuador and Mozambique to produce safe drinking water for human consumption. The present paper describes the main actions carried out within the project AQUAPOT over the last 20 years. It describes the main features of the installed plants and the protocol to choose the best location; it also shows the main results achieved within the project, and discusses the lessons learned throughout the years in relation to the operation of the plants as well as the quality of the treated water.Arnal Arnal, JM.; García-Fayos, B.; Sancho, M. (2018). Application of ultrafiltration for drinking water production in decentralised systems: 20 years of the AQUAPOT project. Desalination and Water Treatment. 103:296-306. https://doi.org/10.5004/dwt.2018.21989S29630610

Estudio de prevalencia de Helicobacter spp. : en 70 perros mediante test de ureasa

En el presente artículo se realiza un estudio de prevalencia de Helicobacter spp. En 70 perros, atendidos en el Hospital Clínico Veterinario de la Facultad de Madrid. Estos animales fueron divididos en dos grupos: animales con enfermedad digestiva y animales sin enfermedad digestiva. Para este estudio se ha utilizado la técnica de la ureasa en biopsias gástricas tomadas por endoscopia. El fundamento de esta técnica se basa en la actividad ureasa que presentan estas bacterias espirales. Los resultados obtenidos determinan una prevalencia de Helicobacter spp. Del 64, 3% (45 de los 70 perros). No hemos encontrado diferencias estadísticamente significativas entre animales sin enfermedad digestiva y animales con enfermedad digestiva. Estos resultados parecen reforzar la teoría de que Helicobacter spp. No es patógeno en el perro, si bien parece necesaria la realización de nuevas investigaciones en este campo

Mitochondria and chromaffin cell function

Producción CientíficaChromaffin cells are an excellent model for stimulus– secretion coupling. Ca2+ entry through plasma membrane voltage-operated Ca2+ channels (VOCC) is the trigger for secretion, but the intracellular organelles contribute subtle nuances to the Ca2+ signal. The endoplasmic reticulum amplifies the cytosolic Ca2+ ([Ca2+]C) signal by Ca2+- induced Ca2+ release (CICR) and helps generation of microdomains with high [Ca2+]C (HCMD) at the subplasmalemmal region. These HCMD induce exocytosis of the docked secretory vesicles. Mitochondria close to VOCC take up large amounts of Ca2+ from HCMD and stop progression of the Ca2+ wave towards the cell core. On the other hand, the increase of [Ca2+] at the mitochondrial matrix stimulates respiration and tunes energy production to the increased needs of the exocytic activity. At the end of stimulation, [Ca2+]C decreases rapidly and mitochondria release the Ca2+ accumulated in the matrix through the Na+/Ca2+ exchanger. VOCC, CICR sites and nearby mitochondria form functional triads that co-localize at the subplasmalemmal area, where secretory vesicles wait ready for exocytosis. These triads optimize stimulus–secretion coupling while avoiding propagation of the Ca2+ signal to the cell core. Perturbation of their functioning in neurons may contribute to the genesis of excitotoxicity, ageing mental retardation and/or neurodegenerative disorders

Control architecture of the ATLAS 2020 lower-limb active orthosis

This paper outlines the control details implemented in the wearable gait exoskeleton ATLAS 2020 for improving the therapy of SMA children. This paper discusses the control challenges of a gait-training wearable exoskeleton for SMA children. Such device would also increase these children's quality of life, achieving a reduction of disability and increased functional independence.Peer reviewe

External Fluctuations in a Pattern-Forming Instability

The effect of external fluctuations on the formation of spatial patterns is analysed by means of a stochastic Swift-Hohenberg model with multiplicative space-correlated noise. Numerical simulations in two dimensions show a shift of the bifurcation point controlled by the intensity of the multiplicative noise. This shift takes place in the ordering direction (i.e. produces patterns), but its magnitude decreases with that of the noise correlation length. Analytical arguments are presented to explain these facts.Comment: 11 pages, Revtex, 10 Postscript figures added with psfig style (included). To appear in Physical Review