2,810 research outputs found

    Zonal flows and long-distance correlations during the formation of the edge shear layer in the TJ-II stellarator

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    A theoretical interpretation is given for the observed long-distance correlations in potential fluctuations in TJ-II. The value of the correlation increases above the critical point of the transition for the emergence of the plasma edge shear flow layer. Mean (i.e. surface averaged, zero-frequency) sheared flows cannot account for the experimental results. A model consisting of four envelope equations for the fluctuation level, the mean flow shear, the zonal flow amplitude shear, and the averaged pressure gradient is proposed. It is shown that the presence of zonal flows is essential to reproduce the main features of the experimental observations.Comment: 19 pages, 7 figure

    Estudio comparativo con microscopio electrónico de barrido de la degradación de una lámina impermeable de cloruro de polivinilo plastificado en diferentes condiciones

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    This paper discusses the analysis of several samples of a plasticized polyvinyl chloride (PVC-P) waterproofing membrane. The samples were extracted from different areas of the same flat roof, which was in service for over 12 years. An original sample of an identical PVC-P membrane that was not installed on the roof was also analyzed. The analysis of the materials was carried out using a scanning electron microscope (SEM). An elemental analysis of every sample was also performed by energy dispersive X-ray spectroscopy (EDS). Micrographs and the elemental composition of the samples were compared with the data obtained in the analysis of the original sample. The results show dehydrochlorination of the polymer in two of the samples studied and great deterioration that was not visible to the naked eye in the sample that was totally exposed to the weather.Este estudio discute el análisis de varias muestras de una membrana impermeable de cloruro de polivinilo plastificado (PVC-P). Las muestras fueron extraídas de diferentes áreas de la misma cubierta plana, que estuvo en servicio durante más de 12 años. Una muestra original de idéntica membrana de PVC-P que no estuvo instalada en la cubierta fue también analizada. El análisis de los materiales se llevó a cabo utilizando un microscopio electrónico de barrido (MEB). Además se realizó un análisis elemental sobre cada una de las muestras mediante espectroscopía de dispersión de energía de rayos X (EDS). Las micrografías, y la composición elemental de las muestras, se comparan con los datos obtenidos en el análisis de la muestra original. Los resultados muestran deshidrocloración del polímero en dos de las muestras estudiadas, y un gran deterioro de la muestra totalmente expuesta a la intemperie, que no era visible a simple vista

    The importance of pelvic ring stabilization as a life-saving measure in pre-hospital - A case report commented by autopsy

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    Hip fractures with unstable pelvic ring have great morbidity and mortality rates. These fractures result from high energy trauma such as falls from heights, road accidents and collapsing structures or other similar mechanisms of action. We report the case of a 63 years old man, construction worker, who stood inside a ditch during a wall construction when he was surprised by this collapse, which resulted in direct trauma to the right thigh and pelvis. The autopsy revealed diaphysis fracture of the right femur with an open book pelvic fracture with severe hemorrhagic infiltration and hematoma of the pelvic muscles without arterial injury. Bone bleeding and the vascular damage associated with disruption of the sacroiliac ligaments promote a very significant bleeding. Simple maneuvers such as sheet circumferential compression to promote pelvic ring closure are effective on stabilizing and closure of the sacroiliac joint. Hip manipulation of the fracture was performed during the necropsy to demonstrate and prove how a simple sheet contention can promote stabilization of the pelvic ring by closing the sacroiliac joints in open book fractures.info:eu-repo/semantics/publishedVersio

    The CWKB particle production and classical condensate in de Sitter spacetime

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    The complex time WKB approximation is an effective tool in studying particle production in curved spacetime. We use it in this work to understand the formation of classical condensate in expanding de Sitter spacetime. The CWKB leads to the emergence of thermal spectrum that depends crucially on horizons (as in de Sitter spacetime) or observer dependent horizons (as in Rindler spacetime). A connection is sought between the horizon and the formation of classical condensate. We concentrate on de Sitter spacetime and study the cosmological perturbation of k=0k=0 mode with various values of m/H0m/H_0. We find that for a minimally coupled free scalar field for m2/H02<2m^2/H_0^2<2, the one-mode occupation number grows more than unity soon after the physical wavelength of the mode crosses the Hubble radius and soon after diverges as N(t)O(1)[λphys(t)/H01]2ν21/4N(t)\sim O(1)[\lambda_{phys}(t)/{H_0^{-1}}]^{2\sqrt{\nu^2-1/4}}, where ν(9/4m2/H02)1/2\nu\equiv (9/4 -m^2/{H_0^2})^{1/2}. The results substantiates the previous works in this direction. We also find the correct oscillation and behaviour of N(z)N(z) at small zz from a single expression using CWKB approximation for various values of m/H0m/H_0. We also discuss decoherence in relation to the formation of classical condensate. We also find that the squeezed state formalism and CWKB method give identical results.Comment: 19 pages, revtex, 5 figure

    Targetability of hyaluronic acid nanogel to cancer cells: In vitro and in vivo studies

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    We have, in previous work developed, characterized and evaluated the biocompatibility of an engineered hyaluronic acid nanogel. Here we assess the targetability of a hyaluronic acid nanogel towards CD44 overexpressing cells, in vitro and in vivo. Results obtained by flow cytometry and confocal fluorescence microscopy shows that nanogel is greatly internalized by non-small cancer lung cells (A549 cells), that overexpress CD44 receptors. The biodistribution and tumor targetability of the nanogel labelled with a near-infrared (NIR) probe were performed, in mice, through a non-invasive imaging system. Results revealed nanogel high targetability towards an induced subcutaneous A549 tumor. Nanogels pharmacokinetics was evaluated also in healthy animals, and Alexa Fluor 680 labelled nanogel exhibited higher accumulation in liver, kidneys and skin. Also, a comparative biodistribution study was performed, using two NIR imaging probes, Cy5.5 and Alexa Fluor 680.The authors thank the FCT Strategic Project of UID/BIO/04469/ 2013 unit, the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124FEDER-027462) and the Project “BioHealth - Biotechnology and Bioengineering approaches to improve health quality”, Ref. NORTE07-0124-FEDER-000027, co-funded by the Programa Operacional Regional do Norte (ON.2 – O Novo Norte), QREN, FEDER. We would like to acknowledge also the support of FCT for the PhD grant reference SFRH/BD/61516/2009. We would also like to thank Bioimaging department on Molecular Medicine Institute (IMM) in Lisbon, namely Dr. José Rino and Dr. António Temudo. Also thank the animal facilities in IMM (Lisbon), specially Dra. Dolores Bonaparte and Dra. Joana Marques. Also, we would like to acknowledge the special contribution of Professor Fatima Baltazar in ICVS (Braga) for kindly grant us CFBE and A549 cell lines.info:eu-repo/semantics/publishedVersio
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