Goldstone bosons and fluctuating hydrodynamics with dipole and momentum conservation

We develop a Schwinger-Keldysh effective field theory describing the hydrodynamics of a fluid with conserved charge and dipole moments, together with conserved momentum. The resulting hydrodynamic modes are highly unusual, including sound waves with quadratic (magnon-like) dispersion relation and subdiffusive decay rate. Hydrodynamics itself is unstable below four spatial dimensions. We show that the momentum density is, at leading order, the Goldstone boson for a dipole symmetry which appears spontaneously broken at finite charge density. Unlike an ordinary fluid, the presence or absence of energy conservation qualitatively changes the decay rates of the hydrodynamic modes. This effective field theory naturally couples to curved spacetime and background gauge fields; in the flat spacetime limit, we reproduce the "mixed rank tensor fields" previously coupled to fracton matter.Comment: 20+10 pages. v2, v3: minor edit

A High Resolution Radio Survey of Class I Protostars

We report the results of a survey of low mass Class I protostars in the cm continuum. In the initial survey, seven sources in the Taurus star formation were observed with the VLA at 0``.25 resolution. All seven sources drive CO outflows and display Herbig-Haro flows in the optical or near infrared wavebands. 4/7 sources were detected, two of which are new discoveries in systems of very low luminosity, one being the lowest luminosity system detected to date in the cm continuum. Notably, three sources were not detected to a 3-sigma limit of 0.10 mJy/beam, which indicates that significant cm continuum emission is not a universal feature of Class I systems with outflow activity. Subsequent observations of HH30, a more evolved Class II system, found no emission to a 3-sigma limit of 0.03 mJy/beam. After comparison with near infrared data, we suggest that the discriminating feature of the detected systems is a relatively high ionisation fraction in the stellar wind. Temporal variability of the outflow may also play a role. The one relatively bright source, IRAS 04016+2610 (L1489 IRS), is clearly resolved on a 0``.4 scale at 2 cm and 3.5 cm. Follow-up imaging with MERLIN did not detect this source with a 0``.04 beam, indicating that the radio emission is generated in a region with a radius of about 25 au, which is broadly similar to the radius of the bipolar cavities inferred from models of near infrared data. Interpretation of this system is complicated by the existence of a quadrupolar outflow, which we originally detected through polarimetric imaging. We present a near infrared H2 image in which a bow shock in the secondary outflow is clearly seen. This complicated structure may have been caused by a gravitational interaction between two protostars.Comment: Accepted by MNRAS. 16 pages, 5 figures, 9 postscript files, 1 Latex fil

A New Type of Supramolecular Fluid Based on H₂O-Alkylammonium/Phosphonium Solutions

Here we show that by adjusting the concentration of tetrabutyl ammonium and phosphonium salts in water (approximate to 1.5-2.0 m), hydrophobic solvation triggers the formation of a unique, highly incompressible supramolecular liquid, with a dynamic structure similar to clathrates, involving essentially all H2O molecules of the solvent. Despite the increasing local order, the thermal diffusivity, and compressibility of these supramolecular liquids is strongly decreased with respect to bulk water due to slower relaxation dynamics. The results presented in this paper open an avenue to design a new family of supramolecular fluids, stable under atmospheric conditions, which can find important technological applications in energy storage and conversion

The First 1 1/2 Years of TOTEM Roman Pot Operation at LHC

Since the LHC running season 2010, the TOTEM Roman Pots (RPs) are fully operational and serve for collecting elastic and diffractive proton-proton scattering data. Like for other moveable devices approaching the high intensity LHC beams, a reliable and precise control of the RP position is critical to machine protection. After a review of the RP movement control and position interlock system, the crucial task of alignment will be discussed.Comment: 3 pages, 6 figures; 2nd International Particle Accelerator Conference (IPAC 2011), San Sebastian, Spain; contribution MOPO01

Glycolysis of high resilience flexible polyurethane foams containing polyurethane dispersion polyol

n the last years, high resilience polyurethane foams (HR foams) production has experienced an intensive growth as a consequence of their wide application field, causing an important increment of the generated waste. HR foams containing PU dispersions polyols are the last tendency in the HR foam industry, due to the improvement of the flame retardant properties and the emissions reduction of volatile compounds in comparison to the traditional graft polymeric HR polyols. In this work the extension of the glycolysis process to the recycling of this kind of foams has been carried out. Diethylene glycol (DEG), glycerol 99% PS and crude glycerol, coming from the biodiesel production, have been assayed as glycolysis agents. All of these glycolysis agents provided a split phase product with an upper phase mainly constituted by a traditional HR polyol and a bottom phase consisting of the excess of glycolysis agent and several reaction byproducts. However, the polyol content in the final product has been greater with the employment of glycerol. Moreover, flexible and rigid foams have been synthesized by using the recycled polyols or the glycolysis bottom phase, respectively. This way, it is achieved a global and sustainable recycling process for the valorization of two waste substances: the HR PU foam and the crude glycerol.En los últimos años, la producción de espumas de poliuretano de alta resiliencia (espumas HR) ha experimentado un intenso crecimiento como consecuencia de su amplio campo de aplicación, provocando un importante incremento de los residuos generados. Las espumas HR que contienen polioles de dispersión de PU son la última tendencia en la industria de las espumas HR, debido a la mejora de las propiedades ignífugas y la reducción de las emisiones de compuestos volátiles en comparación con los tradicionales polioles HR de injerto. En este trabajo se ha llevado a cabo la extensión del proceso de glicólisis al reciclado de este tipo de espumas. Se han ensayado como agentes de glicólisis el dietilenglicol (DEG), el glicerol 99% PS y el glicerol crudo, procedente de la producción de biodiesel. Todos estos agentes de glicólisis proporcionaron un producto de fase dividida con una fase superior constituida principalmente por un poliol HR tradicional y una fase inferior formada por el exceso de agente de glicólisis y varios subproductos de la reacción. Sin embargo, el contenido de poliol en el producto final ha sido mayor con el empleo de glicerol. Además, se han sintetizado espumas flexibles y rígidas utilizando los polioles reciclados o la fase de fondo de glicólisis, respectivamente. De esta forma, se consigue un proceso de reciclaje global y sostenible para la valorización de dos sustancias residuales: la espuma de PU HR y el glicerol crudo

AOLI: Near-diffraction limited imaging in the visible on large ground -based telescopes

The combination of Lucky Imaging with a low order adaptive optics system was demonstrated very successfully on the Palomar 5m telescope nearly 10 years ago. It is still the only system to give such high-resolution images in the visible or near infrared on ground-based telescope of faint astronomical targets. The development of AOLI for deployment initially on the WHT 4.2 m telescope in La Palma, Canary Islands, will be described in this paper. In particular, we will look at the design and status of our low order curvature wavefront sensor which has been somewhat simplified to make it more efficient, ensuring coverage over much of the sky with natural guide stars as reference object. AOLI uses optically butted electron multiplying CCDs to give an imaging array of 2000 x 2000 pixels.Science and Technology Facilities CouncilThis is the author accepted manuscript. The final version is available from SPIE via http://dx.doi.org/10.1117/12.223090

Flexible polyurethane foams synthesized employing recovered polyols from glycolysis: Physical and structural properties

Polyurethane (PU) is one of the most important polymers with a global production of 17.565 million tons, which makes its recycling an urgent task. Besides, the main goal of PU recycling is to recover constituent polyol as a valuable raw material that allows to obtain new PU with suitable properties. Split-phase glycolysis can be considered the most interesting PU recycling process since provides high-quality recovered products in terms of polyol purity. The aim of this work was to evaluate several recovered polyols as replacement of the raw flexible polyether polyol in the synthesis of new flexible PU foams. These recovered polyols come from the split-phase glycolysis of different types of PU foams and employing as cleavage agents diethylene glycol or crude glycerol (biodiesel byproduct). The influence of the foam waste type and of the cleavage agent on the foams properties was analyzed. The recovered polyols were evaluated by performing several foaming tests according to the method of free expansion foaming of conventional flexible foam. Synthesized flexible foams containing different proportions of recovered polyols were characterized by means of scanning electron microscopy, density and tensile properties; obtaining similar and sometimes even better values compared to the foams manufactured from commercial polyols.El poliuretano (PU) es uno de los polímeros más importantes con una producción mundial de 17.565 millones de toneladas, lo que hace de su reciclaje una tarea urgente. Además, el objetivo principal del reciclaje de PU es recuperar el poliol constituyente como una materia prima valiosa que permita obtener nuevo PU con propiedades adecuadas. La glucólisis en fase dividida puede considerarse el proceso de reciclaje de PU más interesante, ya que proporciona productos recuperados de alta calidad en términos de pureza de polioles. El objetivo de este trabajo fue evaluar varios polioles recuperados como reemplazo del poliéter poliol flexible crudo en la síntesis de nuevas espumas de PU flexibles. Estos polioles recuperados provienen de la glucólisis en fase dividida de diferentes tipos de espumas de PU y empleando como agentes de escisión dietilenglicol o glicerol crudo (subproducto del biodiésel). Se analizó la influencia del tipo de residuo de espuma y del agente de desdoblamiento sobre las propiedades de las espumas. Los polioles recuperados se evaluaron realizando varios ensayos de espumado según el método de espumado de expansión libre de espuma flexible convencional. Las espumas flexibles sintetizadas que contenían diferentes proporciones de polioles recuperados se caracterizaron mediante microscopía electrónica de barrido, densidad y propiedades de tracción; obteniendo valores similares ya veces incluso mejores en comparación con las espumas fabricadas a partir de polioles comerciales. © 2017 Wiley Periodicals, Inc. J. Appl. polim. ciencia Las espumas flexibles sintetizadas que contenían diferentes proporciones de polioles recuperados se caracterizaron mediante microscopía electrónica de barrido, densidad y propiedades de tracción; obteniendo valores similares ya veces incluso mejores en comparación con las espumas fabricadas a partir de polioles comerciales. © 2017 Wiley Periodicals, Inc. J. Appl. polim. ciencia Las espumas flexibles sintetizadas que contenían diferentes proporciones de polioles recuperados se caracterizaron mediante microscopía electrónica de barrido, densidad y propiedades de tracción; obteniendo valores similares ya veces incluso mejores en comparación con las espumas fabricadas a partir de polioles comerciales

La inclusió a les aules d'educació infantil

Treball Final de Grau en Mestre o Mestra d'Educació Infantil. Codi: MI1040. Curs acadèmic: 2016/2017El tema de la inclusió és un tema molt important en la societat a la qual vivim. Després d'estar a una escola educativa i analitzar les característiques i proposta pedagògica utilitzada, vaig veure important tractar aquest tema amb els més menuts, ja que, hi ha una gran quantitat d'alumnat immigrant i amb necessitats educatives especials que són acceptats per tothom però sols l'alumnat amb NEE disposa d'un pla d'actuació, la qual cosa veig necessari tractar el tema de la inclusió més enllà de les NEE. En aquest sentit, la inclusió no sols és donar resposta aquelles persones amb necessitats educatives especials, sinó a totes aquelles que necessiten una ajuda pels motius que sigui (persones d’altres cultures, diferents formes de vida, incorporació tarda al sistema educatiu, historia personal, diversitat sexual, etc.) Aquest tema està sustentat per autors com Gerard Ferrer i Sergi Martínez, Pere Pujolàs, Marta Mata o l'autor de la teoria del reconeixement com és Axel Honneth. Per a la realització de la pràctica educativa, s'han plantejat activitats lúdiques i motivadores. Una volta finalitzades les activitats i per a l'obtenció dels resultats, s'ha realitzat un qüestionari prèviament plantejat a les activitats, per veure si aquestes han aconseguit els objectius proposats i a més, per veure la satisfacció dels nens i nenes. Cada una de les activitats disposa d'una taula d'avaluació diferent perquè totes elles no persegueixen els mateixos objectius. Així, aquest projecte d'investigació té com a objectiu donar a conèixer el tema de la inclusió als més menuts, a més, fomentar el principi d'igualtat i les relacions personals, crear un treball cooperatiu i reforçar el reconeixement com a eina per a la inclusió, tot això seguint una metodologia on l'alumne és el centre del seu aprenentatge relacionant conceptes nous amb conceptes que ja havia adquirit

Australian forested wetlands under climate change:Collapse or proliferation?

Climatically driven perturbations (e.g. intense drought, fire, sea surface temperature rise) can bring ecosystems that are already stressed by long-term climate change and other anthropogenic impacts to a point of collapse. Recent reviews of the responses of Australian ecosystems to climate change and associated stressors have suggested widespread ecosystem collapse is occurring across multiple biomes. Two commonly cited case studies concern forested wetland ecosystems: mangrove forest dieback in northern Australia (2015-16) and riverine forest dieback in the south-east of the continent (2002-09). We present an alternative interpretation that emphasises the dominant signal of climate change effects, rather than the interdecadal signal of climate variability that drives wetland forest dynamics. For both the south-east Australian riverine forests and mangroves of northern Australia, aerial extent remains greater after dieback than in the early 1990s. We interpret dieback and defoliation in both systems as a dry phase response and provide evidence of a current and near-future climate change trajectory of increased areal extent and cover (i.e. tree colonisation and range infilling). In both case studies, climate change-driven increases in tree cover and extent are occurring at the expense of wetland grasslands and the important ecosystem functions they support