136 research outputs found

    Stability of liquid bridges subject to an eccentric rotation

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    A cylindrical liquid bridge supported between two circular-shaped disks in isorotation is considered. The effect of an offset between the rotation axis and the axis of the two supporting disks (eccentricity) on the stability of the static liquid bridge is investigated. A numerical method is used to find stable and unstable shapes and to determine the stability limit for different values of eccentricity. The calculated stability limits are compared with analytical results, recovering the same behavior. Numerical results have been also compared with the results of an experiment aboard TEXUS-23, recovering the stability limit and the equilibrium shapes

    Chaotic Synchronization in a Small Network of a Class of Power Systems via Contraction Analysis

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    This paper presents a synchronization analysis of networks of a class of power systems using the contraction theory for nonlinear systems. This analysis is characterized by not being based on Lyapunov's stability theory, that is, it is not required to determine a Lyapunov candidate function. Moreover, from the contraction conditions, robustness of the synchronization can be obtained, in this sense, the analysis method is robust. The analysis consists in identifying or proposing a virtual or auxiliary system which is contracting in a region of the state space. It is intended that in this region the trajectories of the systems on the network converge to those of the virtual system and then obtain the synchronization of the systems in the network. The contribution consists in applying this nontraditional analysis to the problem of chaotic synchronization of a network of a class of power systems

    High-pressure structural phase transitions in CuWO4

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    We study the effects of pressure on the structural, vibrational, and magnetic behavior of cuproscheelite. We performed powder x-ray diffraction and Raman spectroscopy experiments up to 27 GPa as well as ab initio total-energy and lattice-dynamics calculations. Experiments provide evidence that a structural phase transition takes place at 10 GPa from the low-pressure triclinic phase (P-1) to a monoclinic wolframite-type structure (P2/c). Calculations confirmed this finding and indicate that the phase transformation involves a change in the magnetic order. In addition, the equation of state for the triclinic phase is determined: V0 = 132.8(2) A3, B0 = 139 (6) GPa and = 4. Furthermore, experiments under different stress conditions show that non-hydrostatic stresses induce a second phase transition at 17 GPa and reduce the compressibility of CuWO4, B0 = 171(6) GPa. The pressure dependence of all Raman modes of the triclinic and high-pressure phases is also reported and discussed.Comment: 33 pages, 9 figures, 5 table

    Quantifying the Impact on Stormwater Management of an Innovative Ceramic Permeable Pavement Solution

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    [EN] Stormwater management in cities has traditionally been based on centralized systems, evacuating runoff as quickly as possible through drainage networks that collect and convey the runoff to the final point of treatment or the receiving water body. In recent years, a different approach focused on the use of Sustainable Urban Drainage Systems (SUDS) represents a paradigm shift, promoting a decentralized management as close to the runoff source as possible. Among these techniques, permeable pavements represent an effective solution for reducing runoff and providing pollutant treatment. This contribution describes the results obtained from an innovative ceramic permeable pavement developed as part of the LIFE CERSUDS project in the city of Benicassim (Spain). This pavement, composed by modules built from ceramic tiles in stock, allows water infiltration, runoff treatment and water reuse as part of a SUDS built in 2018 and monitored from September 2018 to September 2019. The purpose of the research was to demonstrate the hydraulic performance of the proposed solution through monitoring of runoff quantity and quality variables. Monitoring data analysis have shown positive results, reducing peak runoff rates and the volume of water which is conducted downstream. From the hydrological point of view, the system capacity shown a 100% runoff management for events up to 15-25 mm of precipitation. This is a very significant threshold since these values represent, respectively, the 81% and 91% percentiles for the study area. System performance was confirmed in terms of runoff management and water infiltration. This demonstration case study represents a reference example of urban retrofitting actions which integrate social, economic and environmental aspects.This research was developed within the LIFE CERSUDS project and was financed by the LIFE Programme 2014-2020 of the European Union for the Environment and Climate Action [Reference LIFE15 CCA/ES/000091] with the collaboration of the Generalitat Valenciana through IVACE.Castillo-Rodríguez, JT.; Andrés Doménech, I.; Martín Monerris, M.; Escuder Bueno, I.; Perales-Momparler, S.; Mira-Peidro, J. (2021). Quantifying the Impact on Stormwater Management of an Innovative Ceramic Permeable Pavement Solution. Water Resources Management. 35(4):1251-1271. https://doi.org/10.1007/s11269-021-02778-7S1251127135

    Effect of binary raw materials replacement (quartz and feldspar) for porcelain chamotte on the electro-technical siliceous porcelain properties

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    The hurry for ecological practices and waste control has emerged as an obligation in modern times, demanding precise strategies to restrain waste accumulation and to stimulate recycling and reuse actions to lower the climate effect. The replacement of binary raw materials for porcelain chamotte waste in siliceous porcelain was studied to obtain eco-friendly high-voltage porcelain. Quartz and feldspar were progressively replaced by 5, 10, and 15 wt.% of porcelain chamotte in a conventional siliceous electro-technical porcelain composition. The replacement effect on sintered samples at 1250°C under industrial heat treatment was evaluated by measuring the linear shrinkage, bulk density, porosity, flexural strength, and microhardness technological properties. Phase analysis was carried out by X-ray diffraction. Microstructural characteristics were studied using a scanning electron microscope. The results showed that chamotte-containing samples reached bulk densities of about 2.36 g/cm3 and a porosity percentage near zero. The maximum flexural strength value at glazed states was 87.8 MPa, for 15 wt.% scrap-containing samples. X-ray diffraction studies revealed a higher mullite phase content in chamotte-containing samples. Scanning electronic microscopy images of the polished and etched specimens show the presence of quartz grains and secondary mullite needles embedded in a feldspathic vitreous matrix. The properties reached by the chamotte-containing samples are attractive since the values obtained in terms of flexural strength, density, and porosity are compared to those reported for conventional siliceous porcelain were obtained. The most noticeable result was observed in flexural resistance. The glazed porcelain bodies showed a flexural strength improvement of about 15%. Then, these porcelain compositions suggest an alternative to produce a more sustainable, affordable, and environmentally-friendly porcelain insulator product

    Association between bullying and major depressive disorder in a psychiatric consultation

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    Assess if there is a significant association between being bullied and presenting depressive symptoms. Materials and methods: In the March---October period of the present year, 8---16-year-old children and adolescents that attended psychiatric consultation for the first time in Dr. Eleuterio González Hospital were included in this study. Test Bull-S was used to determine the presence of bullying (Victim subtype); to evaluate depression 2 instruments were used according to age: Children’s Depression Rating Scale-Revised (CDRS-R) for 8---12-year olds and the Birleson Depression Self-Rating Scale (DSRS) for 13---16-year olds. A total of 147 clinical patients were studied (73 women and 74 men). Data were captured in excel and the Statistical Package for the Social Sciences (SPSS) program was used for statistical analysis. Results: A very significant association was found between being bullied and presenting depression (X2 = .289, p = .0004). Conclusions: These data are in agreement with national and international studies, therefore, reinforcing the evidence of such association. This is why we suggest inquiring about bullying in children and adolescents whose chief complaint is depressive symptomatolog

    High-pressure phase transitions and compressibility of wolframite-type tungstates

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    This paper reports an investigation on the phase diagram and compressibility of wolframite-type tungstates by means of x-ray powder diffraction and absorption in a diamond-anvil cell and ab initio calculations. X-ray diffraction experiments show that monoclinic wolframite-type MgWO4 suffers at least two phase transitions, the first one being to a triclinic polymorph with a structure similar to that of CuWO4 and FeMoO4-II. The onset of each transition is detected at 17.1 and 31 GPa. In ZnWO4 the onset of the monoclinic-triclinic transition has been also found at 16.7 GPa. This transition does not involve any change in the atomic coordination as confirmed by x-ray absorption measurements. These findings are supported by density-functional theory calculations, which predict the occurrence of additional transitions upon further compression. Calculations have been also performed for wolframite-type MnWO4, which is found to have an antiferromagnetic configuration. In addition, our study reveals details of the local-atomic compression in MgWO4 and ZnWO4. In particular, below the transition pressure the ZnO6 and equivalent polyhedra tend to become more regular, whereas, the WO6 octahedra remain almost unchanged. Fitting the pressure-volume data we obtained the equation of state for the low-pressure phase of MgWO4 and ZnWO4. These and previous results on MnWO4 and CdWO4 are compared with the calculations. The compressibility of wolframite-type tungstates is also systematically discussed. Finally Raman spectroscopy measurements and lattice dynamics calculations are presented for MgWO4

    LPS promotes Th2 dependent sensitisation leading to anaphylaxis in a Pru p 3 mouse model

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    Pru p 3 is the major peach allergen in the Mediterranean area. It frequently elicits severe reactions, limiting its study in humans, raising the need for animal models to investigate the immunological mechanisms involved. However, no anaphylaxis model exists for Pru p 3. We aimed to develop a model of peach anaphylaxis by sensitising mice with Pru p 3 in combination with lipopolysaccharide (LPS) as an adjuvant. Four groups of mice were sensitised intranasally: untreated; treated with Pru p 3; treated with LPS; treated with Pru p 3 + LPS. After sensitisation mice were intraperitoneally challenged with Pru p 3 and in vivo and in vitro parameters were evaluated. Only mice in the Pru p 3 + LPS group showed anaphylaxis symptoms, including a decrease in temperature. Determination of in vitro parameters showed a Th2 response with an increase of Pru p 3-specific IgE and IgG1. Moreover, at the cellular level, we found increased levels of IgE and IgG1 secreting Pru p 3-specific cells and a proliferative CD4+ T-cell response. These results demonstrate that Pru p 3-specific anaphylaxis can be generated after nasal sensitisation to Pru p 3 in combination with LPS. This is a promising model for evaluating food allergy immunotherapies.Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" PI12 / 02481Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" PI15 / 00559Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD 07/0064Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD12 / 0013/0001Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD07 / 0064/0003Unión Europea, Ministerio de Economía y Competitividad, Instituto de Salud "Carlos III" RD12 / 0013/0016Unión Europea, Ministerio de Andalucía Economía y Conocimiento CTS-7433Unión Europea, Ministerio de Andalucía Economía y Conocimiento C-0044-2012 SAS2013Unión Europea, Ministerio de Andalucía Economía y Conocimiento Ref. CD14 / 00242Unión Europea, Ministerio de Andalucía Economía y Conocimiento BIO2013- 41403-

    Shaping public Opinion for confrontation : catalan independence claims as represented in spanish, catalan, valencian, and basque editorials

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    Editorials represent a newspaper's principal means of ideological positioning and serve to identify the attitude of each newspaper and its readership to some of the main actors in any given conflict, especially those that are political in nature. Catalonia's independence movement has experienced a surge in recent years. The turning point came in July 2010, after Spain's constitutional court ruled against some aspects of Catalonia's Statute of Autonomy (the legislation regulating the relationship between the Catalan autonomous community and the Spanish state). The ruling annulled some of the articles of the statute. The demonstration in support of Catalan independence that took place on September 11, 2012, was considered the most important among several mass rallies held for this purpose over successive years on Catalonia's National Day. This article presents the results of a qualitative and quantitative analysis of editorial articles published around these two key dates, with the goal of studying each newspaper's treatment of political actors and their degree of identification with these actors. Their use of arguments aimed at persuading readers and legitimizing a given position during the specified time periods in 2010 and 2012 will also be studied. The study focuses on the editorial articles published by several newspapers in four distinct regional contexts: Catalonia, Valencia, the Basque Country, as well as the whole of Spain. The analyzed articles were published a few days before and after July 10, 2010, and September 11, 2012
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