Unconventional mechanism of virtual-state population through dissipation

Virtual states are a central concept in quantum mechanics. By definition, the probability of finding a quantum system in a virtual state should be vanishingly small at all times. In contrast to this notion, we report a phenomenon occurring in open quantum systems by which virtual states can acquire a sizable population in the long-time limit, even if they are not directly coupled to any dissipative channel. This means that the situation in which the virtual state remains unpopulated can be metastable. We describe this effect by introducing a two-step adiabatic elimination method, which we termed hierarchical adiabatic elimination, that allows one to obtain analytical expressions of the timescale of metastability in general open quantum systems. We show how these results can be relevant for practical questions such as the generation of stable and metastable entangled states in dissipative systems of interacting qubit

Unconventional mechanism of virtual-state population through dissipation

Virtual states are a central concept in quantum mechanics. By definition, the probability of finding a quantum system in a virtual state should be vanishingly small at all times. In contrast to this notion, we report a phenomenon occurring in open quantum systems by which virtual states can acquire a sizable population in the long-time limit, even if they are not directly coupled to any dissipative channel. This means that the situation in which the virtual state remains unpopulated can be metastable. We describe this effect by introducing a two-step adiabatic elimination method, which we termed hierarchical adiabatic elimination, that allows one to obtain analytical expressions of the timescale of metastability in general open quantum systems. We show how these results can be relevant for practical questions such as the generation of stable and metastable entangled states in dissipative systems of interacting qubit

Obtención de recubrimientos superhidrofugantes para materiales de construcción, mediante el uso de nanopartículas de sílice funcionalizadas

El agente de degradación más importante de los materiales de construcción es el agua. Por esta razón, el desarrollo de productos capaces de evitar la penetración de agua en estos materiales es fundamental para incrementar su durabilidad. En este Trabajo, se propone un procedimiento de síntesis simple, de bajo coste y con posibilidad de aplicación a escala industrial, para producir recubrimientos superhidrofugantes sobre piedras y otros materiales de construcción.60 páginas

Arqueología informática: diseño e implementación de calculadoras mecánicas Odhner con Scratch

[ES] El Aritmómetro de Odhner fue inventado en 1873 en Rusia por Willgodt Theophil Odhner, un inmigrante sueco. Esta calculadora de rueda de pines fue realmente exitosa, pero a pesar de ello la producción se detuvo cuando la fábrica fue nacionalizada y cerrada durante la revolución rusa de 1917. Sin embargo, su legado no acabó ahí, dado que hasta mediados del siglo 20 varias compañías independientes alrededor del mundo se encargaron de fabricar clones de dicho aparato. En este trabajo se realiza una breve investigación sobre las máquinas de cálculo más relevantes que hubo a lo largo de la historia hasta llegar a la de Odhner, la cual es analizada en más detalle, estudiando también el contexto histórico de aquella época. Finalmente, se desarrolla un simulador de este aritmómetro en el lenguaje de programación visual Scratch.[CA] L’aritmòmetre d’Ohner fou inventat en 1873 en Rússia per Willgodt Theophil Odhner, un immigrant suec. Aquesta calculadora de roda de pins va ser realment exitosa, però malgrat açò la producció es va detindre quan la fàbrica va ser nacionalitzada i tancada durant la revolució russa de 1917. No obstant, el seu llegat no va acabar ací, ja que fins a mitjan segle 20 diverses companyies es van encarregar de fabricar clons d’aquest aparell. En aquest treball es realitza una breu investigació sobre les màquines de càlcul que va haver al llarg de la història fins arribar a la d’Odhner, la qual és analitzada en més detall, estudiant també el context històric d’aquella època. Finalment, es desenvolupa un simulador d’aquest aritmòmetre en el llenguatge de programació visual Scratch.[EN] Odhner arithmometer was invented in Russia in 1873 by Willgodt Theophil Odhner, a Swedish immigrant. This pinwheel calculator was really successful, but despite this production came to a halt when the factory was nationalised and closed during the Russian revolution of 1917. However, its legacy did not end there, since various independent companies around the world took it upon themselves to produce clones of said tool. On this paper a brief investigation about the most relevant calculating machines throughout history is carried out, until Odhner’s is reached, which is analysed in more detail, also studying the historical context of the time. Finally, a simulator of this arithmometer is developed using the visual programming language Scratch.González Sánchez, A. (2020). Arqueología informática: diseño e implementación de calculadoras mecánicas Odhner con Scratch. http://hdl.handle.net/10251/150917TFG

Desarrollo de una librería multicuerpo con EcosimPro

En el presente Proyecto de Fin de Carrera se analiza la filosofía de modelado de sistemas multicuerpo, y se estudia como llevar a cabo este tipo de programación en una herramienta de modelado y simulación no-causal llamada EcosimPro. En este documento se explica qué es y como se trabaja con la programación multicuerpo. Por otro lado, se analiza el funcionamiento del programa Ecosimpro y se compara con otro programa similar llamado Modelica. Por último, se crea una librería de programación multicuerpo en EcosimPro, y posteriormente se simula un experimento tomado de Modelica para poder comparar los resultados. _____________________________________________________________________________________________________________________________This Project examines the philosophy of multibody systems modeling, and considers how to perform this type of programming with a non-casual modeling tool called EcosimPro. This document explains how to work with multibody programming. On the other hand, analizes how the program EcosimPro works and is compared with another similar program called Modelica. Finally, it has created a programming multibody library in EcosimPro, subsequently, it has simulated an experiment taken from Modelica to compare the results.Ingeniería Técnica en Mecánic

Granular biomass technology for providing drinking water: microbial versatility and nitrate performance in response to carbon source

AL and RVV are supported by the funds of European Commission through the "European funds for regional development" (EFRE) as well as by the regional Ministry of Economy, Science and Digitalization of Saxony-Anhalt as part of the "Autonomy in old Age" (AiA) research group for "LiLife" Project (Project ID: ZS/2018/11/95324). Authors thank to Mrs. Ilka Kramer for her technical support in sequencing. BMP is supported by the funds of Ministerio de Universidades (Spain Government) and the European Union -NextGenerationEU. The authors would like to acknowledge the support given by the funding proving by LIFE16 ENV/ES/000196 and the RMN270 research group, which was essential for the realization of this research.The aerobic granular biomass technology was optimized for treating nitrate-polluted groundwater based on the biological denitrification processes in order to provide drinking water. Reactors inoculated with granular biomass were operated at progressively lower C/N rate using acetate and methanol to encourage heterotrophic denitrification, in order to meet the recommended requirements described by European Drinking Water Framework Directive. The granulation and long-term stability of granular biomass under low C/N were successful for all stages, demonstrated compactness of granules and absence of filamentous microorganisms. The nitrate removal was similar in methanol- and acetate-fed reactors, occurring in both cases nitrate removal ratios > 80%, and fact allows the selection of one of both depending groundwater polluted case. Also, feeding reactors with 2 C/N ratio showed nitrate removal values of & GE; 95%, treating highly polluted groundwater (100 mg & BULL;L-1). The microbial diversity was higher in the methanol-fed reactor with representative phylotypes as Flavobacterium, Cytophagaceae, NS9 marine group, while species richness was higher in the acetate-fed reactor, which was mainly represented by Flavobacterium genus. Statistical analyses revealed the higher resilience of bacterial population on granules fed with acetate, showing more resistance under drop C/N ratio. Oscillating pollution in groundwater during seasonal periods should be treated using acetate as carbon source for denitrification carried out by granular biomass, while stable pollution concentrations over time allow the use of methanol as a carbon source since the greater microbial diversity allows the elimination of other contaminants present in groundwater.European Union (EU)Regional Ministry of Economy, Science and Digitalization of Saxony-Anhalt ZS/2018/11/95324Ministerio de Universidades (Spain Government)LIFE16 ENV/ES/000196RMN270European Union -NextGenerationE

Enseñanza de la Física (Cinemática y ley de la inercia) a partir de las concepciones de Galileo Galilei, para estudiantes de grado décimo

La propuesta didáctica de este trabajo muestra una perspectiva diferente a la forma tradicional en que se enseña cinemática, que en nuestro contexto es tan operativa y tan poco significativa para los alumnos de grado décimo. Por ello, nos remitimos al creador de ésta, Galileo Galilei, para ver en sus concepciones elementos para lograr una mejor conceptualización por parte de los estudiantes. Y luego, ver la inercia galileana, como un concepto importante dentro de la mecánica. Dicha propuesta, será complementada con animaciones multimedia, como estrategia didáctica para que los estudiantes argumenten y sean críticos de su conocimiento, adoptando una forma dialéctica. Las matemáticas son la clave para entender la naturaleza, pero se busca que los estudiantes puedan vivir de alguna manera dicha idea.Anstract. The methodological approach of this work shows a different perspective to the traditional way it is taught kinematics, which in our context is as little as operational and meaningful for students in grade ten. Therefore, we refer to the creator of this, Galileo Galilei, to see in their conceptions elements to achieve a better conceptualization of the kinematics by students. And then see the Galilean inertia as an important concept in mechanics. This proposal will be complemented with multimedia animations, as a teaching strategy for students to argue and be critical of his knowledge, adopting a dialectical form. Mathematics is the key to understanding nature, but is looking for students to live somehow the idea.Maestrí

Advances in single chain technology

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.-- Review ArticleThe recent ability to manipulate and visualize single atoms at atomic level has given rise to modern bottom-up nanotechnology. Similar exquisite degree of control at the individual polymeric chain level for producing functional soft nanoentities is expected to become a reality in the next few years through the full development of so-called >single chain technology>. Ultra-small unimolecular soft nano-objects endowed with useful, autonomous and smart functions are the expected, long-term valuable output of single chain technology. This review covers the recent advances in single chain technology for the construction of soft nano-objects via chain compaction, with an emphasis in dynamic, letter-shaped and compositionally unsymmetrical single rings, complex multi-ring systems, single chain nanoparticles, tadpoles, dumbbells and hairpins, as well as the potential end-use applications of individual soft nano-objects endowed with useful functions in catalysis, sensing, drug delivery and other uses.Financial support from the Projects MAT2012-31088 (MINECO) and T-654-13 (GV) is acknowledged. M. G.-B. and A. L.-S. are grateful to the University of the Basque Country for their UPV/EHU pre-doctoral grants.Peer Reviewe