1,480 research outputs found
Interacting color strings as the origin of the liquid behavior of the quark-gluon plasma
We study the radial distribution function of the color sources (strings) formed in hadronic collisions and
the requirements to obtain a liquid. As a repulsive interaction is needed, we incorporate a concentric core in
the strings as well as the probability that a string allows core-core overlaps. We find systems where the
difference between the gas-liquid and confined-deconfined phase transition temperatures is small. This
explains the experimentally observed liquid behavior of the quark-gluon plasma above the confineddeconfined
transition temperature.J. E. R. acknowledges financial support from Consejo Nacional de Ciencia y Tecnología (postdoctoral fellowship Grant No. 289198). B. D. was partially supported by a DGAPA-UNAM postdoctoral fellowship and acknowledges support from the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Union’s Horizon 2020 programme under the Marie Sklodowska-Curie grant agreement No. 801538. C. P.
has received financial support from Xunta de Galicia (Centro singular de investigación de Galicia), by European Union ERDF, and by the “María de Maeztu” Units of Excellence program MDM-2016-0692 and the Spanish Research State Agency. We thank Nestor Armesto and David Vergara for their valuable comments. J. E. R. acknowledges financial support from Consejo Nacional de Ciencia y Tecnología (postdoctoral fellowship
Grant No. 289198). B. D. was partially supported by a DGAPA-UNAM postdoctoral fellowship and acknowledges support from the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Union’s Horizon 2020 programme under the Marie
Sklodowska-Curie grant agreement No. 801538. C. P. has received financial support from Xunta de Galicia (Centro singular de investigación de Galicia), by European Union ERDF, and by the “María de Maeztu” Units of Excellence program MDM-2016-0692 and the Spanish Research State Agency. We thank Nestor Armesto and David Vergara for their valuable comments.Publicad
¿Depurar el agua en Almería? ¿Para qué? El uso de las controversias socioquímicas en la prensa
Les difícils relacions entre científics i periodistes per entendre's mútuament serveixen de punt de partida per construir una
«divulgació química» que es transformi en una «comunicació científica com a procés educatiu», problematitzada i que posi
en conflicte els mites, creences o concepcions alternatives de la societat, escolar o no. Les notícies sobre depuració d'aigua
ens permeten transformar el consens en controvèrsia i reflexionar sobre les implicacions per a periodistes i docents.The mutual misunderstandings between scientists and journalists serve as a starting point to build a «chemical
divulgation» which was transformed into a «science communication as an educational process», problematized
conflicts myths, beliefs or alternative conceptions of society, be they scholarly or not. News about water purification
allows us to transform the consensus into controversy and reflect on the implications for journalists and teachers.Las difíciles relaciones entre científicos y periodistas para entenderse mutuamente sirven de punto de partida para construir una «divulgación química» que se transforme en una «comunicación científica como proceso educativo»,
problematizada y que ponga en conflicto los mitos, creencias o concepciones alternativas de la sociedad, escolar o no. Las noticias sobre depuración de agua nos permiten transformar el consenso en controversia y reflexionar sobre las implicaciones para periodistas y docentes
A decentralized framework for multi-agent robotic systems
Over the past few years, decentralization of multi-agent robotic systems has become an important research area. These systems do not depend on a central control unit, which enables the control and assignment of distributed, asynchronous and robust tasks. However, in some cases, the network communication process between robotic agents is overlooked, and this creates a dependency for each agent to maintain a permanent link with nearby units to be able to fulfill its goals. This article describes a communication framework, where each agent in the system can leave the network or accept new connections, sending its information based on the transfer history of all nodes in the network. To this end, each agent needs to comply with four processes to participate in the system, plus a fifth process for data transfer to the nearest nodes that is based on Received Signal Strength Indicator (RSSI) and data history. To validate this framework, we use differential robotic agents and a monitoring agent to generate a topological map of an environment with the presence of obstacles
Spatial variations in the effective elastic thickness of the lithosphere in Southeast Asia
As a proxy for long-term lithospheric strength, detailed information on lateral effective elastic thickness (Te) variations can aid in understanding the distribution pattern of surface deformation and its response to long-term forces. Here we present high-resolution maps of spatial variations of Te for the complex SE Asian region by analyzing the coherence of topography and Bouguer gravity anomaly data. We find that after considering the gravity deficit of less dense sediment, the recovered Te maps are more representative of the geology, particularly in elongated rift basins. The results show that the Te variation pattern in SE Asia, in general, agrees well with its tectonic provinces and major tectonic boundaries. The oceanic basins, the Indosinian suture zones between the Indochina and Sibumasu blocks, and the Makassar Strait are characterized by low Te, while moderate and high Te values are recovered in the Khorat plateau, West Burma, the Singapore Ridge, the Con Song Swell, Borneo, the northern Australian margin and the Molucca Sea. The Te pattern in the south Indonesian margin is complicated by the approach and collision of oceanic plateaus and seamounts with the fore-arc region. The heterogeneous strength features are consistent with the complex assemblage of different tectonic units, and significant deformation during Cenozoic tectonic events. In the Indochina Peninsula, the extruded displacement during the India-Eurasia collision might have been partitioned and absorbed by the combined mechanism of the extrusion and viscous tectonic models. As a result, the offshore displacements of the major strike-slip faults in the South China Sea are much smaller than originally assumed, thus having less effect on the development of the South China Sea than other mechanisms such as the slab pull of the proto-South China Sea. Since the displacement driven by the boundary tectonic forces has been greatly absorbed and decreased by subduction and deformation in the active margins and adjacent weak regions, the motion velocity of the interior regions is greatly lower than the boundary active margins, and they are largely free of seismicity and volcanism. Our results suggest that East Borneo might share a similar crustal basement, and represent a broad tectonic zone of the destroyed Meso-Tethys Ocean extending from West-Middle Java, through East Borneo to northern Borneo of the Sarawak and Sabah. The Indosinian zones between the Indochina and Sibumasu blocks might extend further southeastward across Billiton Island to offshore of southern Borneo, and the Singapore platform and SW Borneo might belong to the same block. The results also show that the internal load fraction F is high in the coastal area of South China, the northern margin of the South China Sea, and the coastal area of Indochina, which, in general, agrees with the distribution of a high-velocity lower crustal layer and Late Cenozoic basaltic rocks
Vitamin C content of rotifers enriched with the microalga Isochrysis AFF. galbana (T-ISO) collected from different growth conditions.
The aim of our study was to evaluate if different vitamin C contents in T-iso from different growth phases and conditions would lead to correspondingly different vitamin C contents in rotifers enriched with these microalgae.We conclude that the vitamin C content of rotifers can be manipulated by enrichment with cultures of T-iso with different vitamin C content, obtained by different growth conditions. However, special care should be taken to ensure that DW:rotifer ratios in the enrichments do not vary much or are above the ratio when maximum ingestion rates are reached. Acknowledgments: This work was supported by project P08-AGR-3695, Junta de Andalucía, Spain and by Interreg Project ECOAQUA, financed by the EDRF (European Regional Development Fund). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.El objetivo de nuestro estudio fue evaluar si los diferentes contenidos de vitamina C en T-iso de diferentes fases y condiciones de crecimiento llevaría a diferentes contenidos de vitamina C en los rotíferos enriquecidos con estas microalgas Nosotros concluimos que el contenido de vitamina C de rotíferos puede ser manipulado mediante el enriquecimiento con cultivos de T-iso con diferente contenido en vitamina C, obtenidos por diferentes condiciones de crecimiento. Sin embargo, se debe tener especial cuidado para asegurar que en peso seco, las relaciones de rotíferos en los enriquecimientos no varían mucho y están por encima de la tasa cuando se alcanzan los niveles máximos de ingestión. Agradecimientos: Este trabajo fue apoyado por el proyecto P08-AGR-3695, Junta de Andalucía, España y por Interreg EcoAqua proyecto, financiado por el FEDER (Fondo Europeo de Desarrollo Regional). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.</p
Oxidative Stress in Cystic Fibrosis
Airway infection leads to progressive damage of the lungs in patients with cystic fibrosis (CF). Oxidative stress has been implicated as a causative factor in the aetiology of that process. Supplementation with antioxidant micronutrients (vitamin E, vitamin C, ß-carotene and selenium), docosahexaenoic acid or glutathione might therefore be helpful in maintaining an adequate redox balance. Current literature suggests a relationship between oxidative status and lung function. In this chapter we will summarize the main pathways of oxidative stress, focusing on results of new antioxidant treatments
Analog Models of Fold-and-Thrust Wedges in Progressive Arcs: A Comparison With the Gibraltar Arc External Wedge
The timing and kinematics of the different types of structures and the associated
vertical-axis rotations that permit an arcuate external wedge to acquire progressively
its curved shape throughout its deformation history—known as progressive arcs—are
key questions in natural cases of arcuate fold-and-thrust belts that we want to address
through analog modeling. We present laboratory models of fold-and-thrust belts formed
with a backstop that deforms in map view to simulate progressive arcs in a thin-skinned
tectonic regime. Our setup makes use of a deformable backstop rigid enough to push
from behind the initial parallelepiped but deformable in map view. This innovative design
permits us to increase the amplitude of the arc indenting in the model as its radius
of curvature decreases, that is, it simulates a progressive arc. Taking the Gibraltar Arc
external wedge situated in the western Mediterranean to scale our models in terms of
rheology, velocities, and sizes, four types of experiments were made. We varied the type
of substratum (sand or silicone), the silicone thickness, and the width and length of the
initial analog pack in order to test the influence of each of these parameters on the
resulting fold-and-thrust belts. All experiments led to the formation of arcuate wedges
where strain was partitioned into: (a) arc-perpendicular shortening, accommodated by
thrusts which main structural trend is broadly subparallel to the indenter shape and
with divergent transport directions, and (b) arc-parallel stretching, accommodated by
normal and conjugate strike-slip faults. The normal and strike-slip faults contributed to the
fold-and-thrust belt segmentation and the formation of independent blocks that rotated
clockwise and counterclockwise depending on their position within the progressive arc.
Our experiments allow to simulate and understand the finite deformation mode of the
external wedge of the Gibraltar Arc. Accordingly, they shed light on how an arcuate
fold-and-thrust belt can develop progressively in terms of structural trend and transport
directions, types and distribution of the structures accommodating strain partition, and
timing of vertical-axis rotations.This study was supported by projects RNM-0451, EST1/00231,
CGL2017-89051-P, PGC2018-100914-B-I00, and UPO 1259543
Evaluación del comportamiento mecánico de mezclas asfálticas templadas con 100 % de material reciclado
The use of Half Warm Mixes with high Reclaimed Asphalt content (HWMRA) has the potential to generate significant environmental advantages such as the reduction in consumption of natural resources and the emission of gases into the atmosphere. This paper therefore focuses on demonstrating the viability of using these types of mixes in wearing courses. For this purpose, an HWMRA with 70 % and 100 % Reclaimed Asphalt Pavement (RAP) and emulsion were designed in the laboratory. The performance of the mixes was then assessed and compared with that of conventional Hot Mix Asphalt. In a second stage, the mixes were manufactured in-plant, and laid and compacted in an Accelerated Pavement Test track. The cores were then extracted and tested for stiffness modulus and resistance to fatigue. The results from the tests conducted with both the laboratory specimens and the cores showed that the performance of HWMRA is comparable to that of HMA. These findings encourage greater confidence in promoting the use of these types of sustainable asphalt mixes.La utilización de mezclas asfálticas templadas con alto contenido de asfalto reciclado (HWMRA) conlleva ventajas medioambientales como la reducción del consumo de recursos naturales y la emisión de gases a la atmósfera. Este artículo se centra en mostrar la viabilidad de este tipo de mezclas para capas de rodadura. Para ello, se diseñaron mezclas HWMRA con 70 % y 100 % de asfalto reciclado en el laboratorio y se evaluó y comparó su comportamiento con una mezcla caliente convencional. En una segunda etapa, las mezclas fueron fabricadas en planta, extendidas y compactadas en una pista de ensayo acelerado de pavimentos. A continuación, se extrajeron testigos y se ensayaron para conocer su módulo de rigidez y resistencia a fatiga. Tanto los resultados de laboratorio como tras la fabricación en planta y puesta en obra mostraron que el comportamiento de mezclas HWMRA es comparable al de mezclas calientes convencionales. Dicha conclusión puede aportar confianza a este tipo de mezclas sostenibles promoviendo su mayor utilización
The thermal evolution of Mars as constrained by paleo-heat flows
Lithospheric strength can be used to estimate the heat flow at the time when a given region was deformed, allowing us to constrain the thermal evolution of a planetary body. In this sense, the high (>300 km) effective elastic thickness of the lithosphere deduced from the very limited deflection caused by the north polar cap of Mars indicates a low surface heat flow for this region at the present time, a finding difficult to reconcile with thermal history models. This has started a debate on the current heat flow of Mars and the implications for the thermal evolution of the planet. Here we perform refined estimates of paleo-heat flow for 22 martian regions of different periods and geological context, erived from the effective elastic thickness of the lithosphere or from faulting depth beneath large thrust faults, by considering regional radioactive element abundances and realistic thermal conductivities for the crust and mantle lithosphere. For the calculations based on the effective elastic thickness of the lithosphere we also consider the respective contributions of crust and mantle lithosphere to the total lithospheric strength. The obtained surface heat flows are in general lower than the equivalent radioactive heat production of Mars at the corresponding times, suggesting a limited contribution from secular cooling to the heat flow during the majority of the history of Mars. This is contrary to the predictions from the majority of thermal history models, but is consistent with evidence suggesting a currently fluid core, limited secular contraction for Mars, and recent extensive volcanism. Moreover, the interior of Mars could even have been heating up during part of the thermal history of the planet
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