Extra-Heavy Crude Oil Viscosity Reduction Using and Reusing Magnetic Copper Ferrite Nanospheres

The main objective of this study is the synthesis, use, and reuse of magnetic copper ferrite nanospheres (CFNS) for extra-heavy oil viscosity reduction. The CFNS were synthesized using a solvothermal method resulting in mean particle size of 150 nm. Interactions of CFNS with the crude oil were evaluated through asphaltene adsorption isotherms, as well as static and dynamic rheology measurements for two cycles at 25 ◦C. Adsorption and desorption experiments corroborated that most of the asphaltenes adsorbed can be removed for nanoparticle reuse. During the rheology tests, nanoparticles were evaluated in the first cycle at different concentrations from 300 to 1500 mg/L, leading to the highest degree of viscosity reduction of 18% at 500 mg/L. SiO2 nanoparticles were evaluated for comparison issues, obtaining similar results regarding the viscosity reduction. After measurements, the CFNS were removed with a magnet, washed with toluene, and further dried for the second cycle of viscosity reduction. Rheology tests were performed for a second time at a fixed concentration of 500 mg/L, and slight differences were observed regarding the first cycle. Finally, changes in the extra-heavy oil microstructure upon CFNS addition were observed according to the significant decrease in elastic and viscous moduli.Spanish Project ref. RTI2018-099,224-B-I00 from ERDF/Ministry of Science, Innovation and UniversitiesState Research Agency. M.V.L.-RJunta de Andalucía, Spain, RNM-366 research grou

A Rewriting Logic Semantics for ATL

As the complexity of model transformation (MT) grows, the need to rely on formal semantics of MT languages becomes a critical issue. Formal semantics provide precise speci cations of the expected behavior of transformations, allowing users to understand them and to use them properly, and MT tool builders to develop correct MT engines, compilers, etc. In addition, formal semantics allow modelers to reason about the MTs and to prove their correctness, something specially important in case of large and complex MTs (with, e.g., hundreds or thousands of rules) for which manual debugging is no longer possible. In this paper we give a formal semantics of the ATL 3.0 model transformation language using rewriting logic and Maude, which allows addressing these issues. Such formalization provides additional bene ts, such as enabling the simulation of the speci cations or giving access to the Maude toolkit to reason about them

Specification and simulation of queuing network models using Domain-Specific Languages

Queuing Network Models (QNMs) provide powerful notations and tools for modeling and analyzing the performance of many different kinds of systems. Although several powerful tools currently exist for solving QNMs, some of these tools define their own model representations, have been developed in platform-specific ways, and are normally difficult to extend for coping with new system properties, probability distributions or system behaviors. This paper shows how Domain Specific Languages (DSLs), when used in conjunction with Model-driven engineering techniques, provide a high-level and very flexible approach for the specification and analysis of QNMs. We build on top of an existing metamodel for QNMs (PMIF) to de ne a DSL and its associated tools (editor and simulation engine), able to provide a high-level notation for the specification of different kinds of QNMs, and easy to extend for dealing with other probability distributions or system properties, such as system reliability.Ministerio de Ciencia e Innovación TIN2011-2379

A Domain Specific Visual Language for Modeling Power-Aware Reliability in Wireless Sensor Networks

Reliability is an attribute that appears in all quality models, so it is important to take it into account when developing any kind of system. Its evaluation at latter stages of the software development may force the re-engineering of im-portant parts of the system, something very costly. This is why it should be raised to the system design phase. Among the systems where reliability is a crucial issue, some wireless sensor network (WSN) protocols aim to extend the networks lifetime as much as possible, so a more reliable network will live longer. Following a model-driven engineering (MDE) approach, we propose the use of domain speci c visual lan- guages (DSVLs) to model the reliability of systems based on components by means of in-place behavioral rules and by modeling how the state of the components changes. We have developed as well a DSVL for modeling and analyzing reliability properties of a WSN protocol based on local in- formation, namely directional source-aware routing protocol (DSAP).Ministerio de Ciencia e Innovación TIN2011-2379

Introducing Approximate Model Transformations

Model transformations dealing with very large models need to count on mechanisms and tools to be able to manage them. The usual approach to improve performance in these cases has focused on the use of concurrency and parallelization techniques, which aim at producing the correct output model(s). In this paper we present our initial approach to produce target models that are accurate enough to provide meaningful and useful results, in an efficient way, but without having to be fully correct. We introduce the concept of Approximate Model Transformations.Ministerio de Ciencia e Innovación TIN2011-23795European Commission ICT Policy Support Programme 31785

Otros tiempos, nuevas visiones del liderazgo educativo

La palabra liderazgo condensa una de las líneas de investigación más importantes y recurrentes de los estudios sobre las organizaciones en general y sobre las educativas en particular. No es por casualidad. Una gran cantidad de estudios confirman los efectos positivos del liderazgo sobre una variedad de aspectos organizativos entre los que destacan la cohesión, el clima social y la moral de los miembros de la organización, etc. En el ámbito educativo, el liderazgo aparece como uno de los factores con más incidencia –tras la enseñanza directa en clase- sobre los resultados escolares. Los estudios sobre el liderazgo se encuentran precisamente en este momento en una encrucijada. A pesar de los esfuerzos de muchos estudiosos del tema, dichos estudios no terminan de desembarazarse de las perspectivas reduccionistas que han dominado el campo desde su fundación. Unas perspectivas que han aportado un exceso de recetas y lugares comunes sobre cómo conseguir el éxito en la dirección de personas y grupos que resulta claramente inútil y lejana a quienes asumen tareas de responsabilidad en las instituciones educativas. Esto hace más necesaria que nunca una investigación basada en la práctica, bien fundamentada metodológicamente, que asuma el liderazgo como un fenómeno social complejo y nos proporcione evidencias sobre su relación con otros aspectos relevantes de la práctica escolar

Carbon-based honeycomb monoliths for environmental gas-phase applications

Honeycomb monoliths consist of a large number of parallel channels that provide high contact efficiencies between the monolith and gas flow streams. These structures are used as adsorbents or supports for catalysts when large gas volumes are treated, because they offer very low pressure drop, short diffusion lengths and no obstruction by particulate matter. Carbon-based honeycomb monoliths can be integral or carbon-coated ceramic monoliths, and they take advantage of the versatility of the surface area, pore texture and surface chemistry of carbon materials. Here, we review the preparation methods of these monoliths, their characteristics and environmental applications

On the Modular Specification of Non-Functional Properties in DSVLs

In previous work we have presented an approach to monitor nonfunctional properties of systems modeled in terms of domain specific visual languages using observers. In this work we present an approach to decouple the definition of observers behavior and systems behavior. Having a library with different kinds of observers behavior, and having the behavioral definition of the system, weaving links can be established among them in order to include observers in the system behavioral specification

A Powerful Tool for Optimal Control of Energy Systems in Sustainable Buildings: Distortion Power Bivector

In the field of building constructions, there is undeniably a growing need to optimize the energy systems which are a key target in new modern constructions and industrial buildings. In this sense, energy systems are being traced for the development of energy distribution networks that are increasingly smart, efficient, and sustainable. Modern generation and distribution energy systems, such as microgrids control systems, are being affected by the presence of linear and nonlinear loads, resulting a distorted voltage and current waveforms. Thus, it is stated that industrial and residential building heating and cooling loads behave essentially like sources of harmonics. This paper presents a new framework based on geometric algebra (GA) to the definition of a multivectorial distortion power concept, which is represented by a bivector that is geometrically interpreted to distinguish the rotated distortion and distortion power bivectors in these kinds of loads. Both bivectors, and their relations to the phase angles of distorted voltage are the main subject of this paper to interpret an optimal control of building energy. Numerical examples are used to illustrate of the suggested distortion power concept, as well as the information it provides for energy control in new buildings in a more sustainable way