2,893 research outputs found

    Graph complexes in deformation quantization

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    Kontsevich's formality theorem and the consequent star-product formula rely on the construction of an LL_\infty-morphism between the DGLA of polyvector fields and the DGLA of polydifferential operators. This construction uses a version of graphical calculus. In this article we present the details of this graphical calculus with emphasis on its algebraic features. It is a morphism of differential graded Lie algebras between the Kontsevich DGLA of admissible graphs and the Chevalley-Eilenberg DGLA of linear homomorphisms between polyvector fields and polydifferential operators. Kontsevich's proof of the formality morphism is reexamined in this light and an algebraic framework for discussing the tree-level reduction of Kontsevich's star-product is described.Comment: 39 pages; 3 eps figures; uses Xy-pic. Final version. Details added, mainly concerning the tree-level approximation. Typos corrected. An abridged version will appear in Lett. Math. Phy

    Symmetric Spaces and Star representations II : Causal Symmetric Spaces

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    We construct and identify star representations canonically associated with holonomy reducible simple symplectic symmetric spaces. This leads the a non-commutative geometric realization of the correspondence between causal symmetric spaces of Cayley type and Hermitian symmetric spaces of tube type.Comment: 13 page

    NANTEN 12CO (J=1-0) observations around the star WR 55

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    Context: A complete study of the molecular and ionized gas in the environs of the nebula RCW 78 around WR 55 is presented. Aims: The aim of this work is to investigate the spatial distribution, physical characteristics, and kinematical properties of the molecular gas linked to the galactic nebula RCW 78 to achieve a better understanding of its interaction with the star and with the ionized gas. Methods: This study was based on 12CO(1-0) fully sampled observations of a region of ~0.45{\deg} in size around the star WR 55 and the nebula RCW 78 obtained with the 4-m NANTEN telescope, radio continuum archival data at 1.4 and 4.85 GHz, obtained from SGPS and PMNRAO Southern Radio Survey, respectively, and available infrared MIPSGAL images at 24 microns. Results: A molecular gas component in the velocity range from ~ -58 to -45 km s-1, compatible with the velocity of the ionized gas, was found to be associated with the optical nebula. Adopting a distance of ~ 5 kpc, the mass of this molecular component is about 3.4 x 10^4 Msun. The analysis of the molecular data revealed the presence of a velocity gradient, in agreement with the Halpha line. New radiocontinuum flux density determinations confirm the thermal nature of RCW 78. This indicates that the ionized gas in RCW 78 arises from photoionization of the molecular gas component in the velocity range from -58 km s-1 to -45 km s-1. A molecular concentration at a velocity of -56.1 km s-1 (identified as C1) is very likely associated with the star HD 117797 and with a collection of candidate YSOs, lying at a distance of 3.9 kpc, while the rest of the molecular gas at velocities between -56 and -46 km s-1 constitute an incomplete ring-like structure which expands around WR 55 at a velocity of about ~ 5 km s-1. Mechanical energy and time requirements indicate that WR 55 is very capable of sustaining the expansion of the nebula.Comment: 14 pages, 10 figures.Accepted for publication in A&

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

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    [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

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    [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

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

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    [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

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

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    [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

    La Iconografía Musical Como Materia Interdisciplinar Su Presencia En Los Estudios Musicales Universitarios En España

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    En el presente artículo se pretende poner en relieve la naturaleza interdisciplinar de la iconografía musical como materia en relación a cuestiones epistemológicas y metodológicas. Para ello, además de establecer un estado de la cuestión, se acotan los términos “disciplina” e “interdisciplina”, y en este último caso, se delimitan sus categorías. Además, se indaga acerca de la presencia de la iconografía musical como materia académica en los estudios de Grado de Musicología en España a través de sus planes de estudios. Se concluye que su presencia en el ámbito universitario es aceptable a tenor de los porcentajes obtenidos, si bien como materia optativa, y que conviene delimitar todavía ciertos preceptos en relación a la iconografía musical, especialmente de tipo metodológico. This article aims to highlight the interdisciplinary nature of music iconography as a subject in relation to epistemological and methodological issues. In addition, to establishing the state of the question, the terms “discipline” and “interdisciplinary” are delimited, as well as their categories. Furthermore, it investigates about the presence of music iconography as an academic subject in Musicology Degree in Spain through its curriculum. It is concluded that its presence in the university field is acceptable, although as an optional subject, and that certain precepts should still be defined in relation to music iconography, especially in a methodological aspects

    The infrared and molecular environment surrounding the Wolf-Rayet star WR130

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    We present a study of the molecular CO gas and mid/far infrared radiation arising from the environment surrounding the Wolf-Rayet (W-R) star 130. We use the multi-wavelength data to analyze the properties of the dense gas and dust, and its possible spatial correlation with that of Young Stellar Objects (YSOs). We use CO J=1-0 data from the FCRAO survey as tracer of the molecular gas, and mid/far infrared data from the recent WISE and Herschel space surveys to study the dust continuum radiation and to identify a population of associated candidate YSOs. The spatial distribution of the molecular gas shows a ring-like structure very similar to that observed in the HI gas, and over the same velocity interval. The relative spatial distribution of the HI and CO components is consistent with a photo-dissociation region. We have identified and characterized four main and distinct molecular clouds that create this structure. Cold dust is coincident with the dense gas shown in the CO measurements. We have found several cYSOs that lie along the regions with the highest gas column density, and suggest that they are spatially correlated with the shell. These are indicative of regions of star formation induced by the strong wind and ionization of the WR star.Comment: 15 pages, 12 figures, 6 Tables. Accepted for publication in MNRA
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