Energy Technology Data Exchange (ETDEWEB)
Saitowitz-Fenton, S.J. [University of Capetown, (South Africa). Dept of Archaeology
1997-12-31
Luxury goods, used in Muslim and medieval long distance trade between ca. AD 900-1250, found an important market among the Iron Age peoples of southern Africa. Indirect evidence of this trade can be seen in the form of archaeological collections of glass beads at sites throughout Africa and Southeast Asia. Texts, chronicles, glass weights, scribal notes and receipts confirm that it was already a successful industrial centre with a history of glass-making when the Fatimids gained control of Egypt. In this study the author addressed three aspects of research to investigate the trade networks associated with internal and foreign contact: (1) the manufacturing origins of the beads, (2) who brought them to southern Africa, and (3) their dispersal in the region. Glass material from Egypt, Palestine, Syria and Southeast Asia was used for comparison, and as possible source material. Scientific techniques were used to confirm these operations. The beads were described, classified, and sampled selectively for physical and chemical analysis. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) used to determine the rare earth element (REE) shows that a particular glass, used to make beads in Egypt, is the same as that used to make some of the beads found at sites in the northern and eastern Transvaal. They document the existence of a trade link with the Mediterranean via the Red Sea 1000 years ago. Until now, both the origin of this contact and the extent of indigenous responses were largely unknown. These findings cast a different light on maritime trade along the east coast of Africa a millennium ago, and on external influences which helped to launch significant political developments in southern Africa.
Microstructural evaluation of oxide layers in CaO-added Mg alloys
International Nuclear Information System (INIS)
Highlights: • Oxidation layer thickness of CaO added AM60 increases with increasing amounts of CaO. • Effect of CaO is that the columnar grains on AM60 grow along the [1 0 0]MgO. • A initial oxidation layer thickness and ignition temperature is closely connected. • The columnar oxide layer formed due to Ca, which dissolved from CaO. - Abstract: A transmission electron microscopy analysis was conducted on the oxide layers of Mg–5.5Al–0.25Mn (AM60) alloys with different levels of CaO content formed in a thermogravimetric analyzer (TGA) system at 450 °C for 7 h. It was found that the oxide layer in AM60 + CaO grew as a columnar structure and, resultantly, that the oxide layers had different thicknesses with different levels of CaO content. The columnar oxide grains that were formed on the Mg + CaO alloy grew on the [1 0 0]MgO, resulting in a more compact and thicker initial oxide layer compared to the normal oxide layer. The columnar growth of the oxide layer in AM60 + CaO formed due to the Ca, which dissolved from CaO
Gas Metal Arc Welding Using Novel CaO-Added Mg Alloy Filler Wire
Directory of Open Access Journals (Sweden)
Minjung Kang
2016-07-01
Full Text Available Novel “ECO Mg” alloys, i.e., CaO-added Mg alloys, which exhibit oxidation resistance during melting and casting processes, even without the use of beryllium or toxic protection gases such as SF6, have recently been introduced. Research on ECO Mg alloys is still continuing, and their application as welding filler metals was investigated in this study. Mechanical and metallurgical aspects of the weldments were analysed after welding, and welding behaviours such as fume generation and droplet transfer were observed during welding. The tensile strength of welds was slightly increased by adding CaO to the filler metal, which resulted from the decreased grain size in the weld metal. When welding Mg alloys, fumes have been unavoidable so far because of the low boiling temperature of Mg. Fume reduction was successfully demonstrated with a wire composed of the novel ECO Mg filler. In addition, stable droplet transfer was observed and spatter suppression could be expected by using CaO-added Mg filler wire.
Solid solution formation and microstructure of UO2 added with Nb and Ca
International Nuclear Information System (INIS)
Preparation of UO2 fuels added with Nb and Ca has been done by mixing UO2 with Nb2O5 and CaUO4 oxides respectively and heating them at 1390degC in stream of helium. Characterization has been then carried out with aid of X-ray diffraction analysis and metallography. The results can be summarized as follows. Nb could dissolve and form solid solution in UO2 with y up to 0.01, where y = Nb/(Ub+U) atomic ratio. The effect of Ca on the change of lattice parameter of the UO2 could be explained well using the simple ionic model, and according to this model, Ca occupies uranium sublattice of the UO2 (substitutional mechanism). Observation of the microstructure of the fuels showed that Nb created large grains and pores. The pores enlarged whether a liquid second phase was present or not. However, the grains did not enlarge and tended to be spherical when the liquid second phase was present. The structure of the liquid second phase could not be determined, but it had a melting point of 1328degC as confirmed by DTA. The evaluation also showed that Ca created small grains and pores. The difference in the grain and pore structure between (Nb,U)O2+x and (Ca,U)O2+x fuels was considered to be strongly due to the different lattice defect created by Nb and Ca, where Nb created a uranium vacancy which is considered to enhance the grain and pore growth and Ca created an oxygen vacancy which is considered to be less effective to enhance grain and pore growth. (author)
Lindquist, Ole
1994-01-01
Thesis also available on the Fishernet Project's website: http://fishernet.is/en/whale-a-seal-hunting By way of introduction the thesis considers Norse whaling history, in general, concepts like 'whaling tradition', 'whaling culture', and describes the approach to the divers studies of cetaceans in Norse peasant fisherman economy and culture and of Norse whaling techniques, ca 900-1900 AD. It is argued that the Icelandic littoral and in...
Cabaleri, Nora G.; Benavente, Cecilia A.
2013-02-01
The Las Chacritas Member is the lower part of the Cañadón Asfalto Formation (Jurassic). The unit is a completely continental limestone succession with volcanic contributions that were deposited during the development of the Cañadón Asfalto Rift Basin (Chubut province, Patagonia, Argentina). A detailed sedimentological analysis was performed in the Fossati depocenter to determine the paleoenvironments that developed in the context of this rift. The Las Chacritas Member represents a carbonate paleolake system with ramp-shaped margins associated with wetlands that were eventually affected by subaerial exposure and pedogenesis. This process is represented by three main subenvironments: a) a lacustrine setting sensu stricto (lacustrine limestone facies association), represented by Mudstones/Wackestones containing porifera spicules (F1), Intraclastic packstones (F6) and Tabular stromatolites (F10) in which deposition and diagenesis were entirely subaqueous; b) a palustrine setting (palustrine limestone facies association) containing Microbial Mudstones (F2), Intraclastic sandy packstone with ostracode remains (F3), Oncolitic packstone (F5), Brecciated limestone (F7) and Nodular-Mottled limestone (F8) representing shallow marginal areas affected by groundwater fluctuations and minor subaerial exposure; and c) a pedogenic paleoenvironment (pedogenic limestone facies association) including Intraclastic limestone (F4) and Packstones containing Microcodium (F9) facies displaying the major features of subaerial exposure, pedogenic diagenesis and the development of paleosols. The fluvial-palustrine-lacustrine succession shows a general shallow upward trend in which contraction-expansion cycles are represented (delimited by exposure and surface erosion). The variations in the successive formations reflect the responses to fluctuations in a combination of two major controls, the tectonic and local climatic variables. The predominance of the palustrine facies associations was
Hereford, R.
2002-01-01
Valley-fill alluvium deposited from ca. A.D. 1400 to 1880 is widespread in tributaries of the Paria River and is largely coincident with the Little Ice Age epoch of global climate variability. Previous work showed that alluvium of this age is a mappable stratigraphic unit in many of the larger alluvial valleys of the southern Colorado Plateau. The alluvium is bounded by two disconformities resulting from prehistoric and historic arroyo cutting at ca. A.D. 1200-1400 and 1860-1910, respectively. The fill forms a terrace in the axial valleys of major through-flowing streams. This terrace and underlying deposits are continuous and interfinger with sediment in numerous small tributary valleys that head at the base of hillslopes of sparsely vegetated, weakly consolidated bedrock, suggesting that eroded bedrock was an important source of alluvium along with in-channel and other sources. Paleoclimatic and high-resolution paleoflood studies indicate that valley-fill alluviation occured during a long-term decrease in the frequency of large, destructive floods. Aggradation of the valleys ended about A.D. 1880, if not two decades earlier, with the beginning of historic arroyo cutting. This shift from deposition to valley entrenchment near the close of the Little Ice Age generally coincided with the beginning of an episode of the largest floods in the preceding 400-500 yr, which was probably caused by an increased recurrence and intensity of flood-producing El Nin??o events beginning at ca. A.D. 1870.
The period AD 900 to 1300, internationally referred to as the Medieval Warm Period, is a critical time for the archaeological record of the Southwestern USA. During the Medieval Warm Period both alluvial and eolian sedimentation increased, but not to the magnitude of the middle Holocene (the Altithe...
DENSIDAD Y DISTRIBUCIÓN SOBRE CSMA/CA EN REDES IEEE 802.11G EN MODO AD HOC
José Domínguez
2009-01-01
El propósito principal de la presente investigación, fue determinar la influencia de la densidad y distribución de hosts sobre el control de acceso al medio en redes IEEE 802.11g, tomando como variables fundamentales la densidad y distribución de los mismos y el protocolo CSMA/CA para el acceso al medio de transmisión. La investigación fue de tipo explicativa, con un diseño experimental puro. La misma se basó en los postulados teóricos de Bates (2003), Comer (2000), León García (2001), Sta...
Holwerda, Femke M; Pol, Diego; Rauhut, Oliver W M
2015-01-01
The early Middle Jurassic is regarded as the period when sauropods diversified and became major components of the terrestrial ecosystems. Not many sites yield sauropod material of this time; however, both cranial and postcranial material of eusauropods have been found in the Cañadón Asfalto Formation (latest Early Jurassic-early Middle Jurassic) in Central Patagonia (Argentina), which may help to shed light on the early evolution of eusauropods. These eusauropod remains include teeth associated with cranial and mandibular material as well as isolated teeth found at different localities. In this study, an assemblage of sauropod teeth from the Cañadón Asfalto Formation found in four different localities in the area of Cerro Condor (Chubut, Argentina) is used as a mean of assessing sauropod species diversity at these sites. By using dental enamel wrinkling, primarily based on the shape and orientation of grooves and crests of this wrinkling, we define and describe three different morphotypes. With the exception of one taxon, for which no cranial material is currently known, these morphotypes match the local eusauropod diversity as assessed based on postcranial material. Morphotype I is tentatively assigned to Patagosaurus, whereas morphotypes II and III correspond to new taxa, which are also distinguished by associated postcranial material. This study thus shows that enamel wrinkling can be used as a tool in assessing sauropod diversity.
Yuan, W. X.; Hark, S. K.
2010-03-01
CaCu3Ti4O12 (CCTO), an unusual perovskite-like ceramic, is known for its extraordinarily high (˜10^4) and relatively frequency independent dielectric constant. It has drawn a lot of attention recently because of its potential applications in microelectronics and microwave devices. In this investigation, HfO2 powder was added to a pre-reacted CCTO powder, which was synthesized by a conventional solid-state reaction, at different concentrations from 1 to 70 wt% and the mixture was sintered into disc-shaped ceramic samples. The effects of adding HfO2 on the microstructure and dielectric properties of CCTO ceramics were investigated. In general, we found that the dielectric constant tends to increase with HfO2 addition up to 8 wt% and then decrease with further addition. Moreover, the dielectric loss was also influenced by the addition of HfO2, and a low loss tangent of ˜0.035 was obtained. The ac conductivity, impedance, complex dielectric permittivity and electric modulus graphs were used to analyze the data. These observations were explained on the basis of the internal-barrier-layer capacitor model with Maxwell-Wagner relaxations.
Norse Greenland dietary economy ca. AD 980-ca. AD 1450
DEFF Research Database (Denmark)
Arneborg, J.; Lynnerup, Niels; Heinemeier, Jan;
2012-01-01
An initial study of the C values for human bone collagen of 27 Norse Greenlanders in the late 1990s suggested a change in the Norse diet from predominantly terrestrial to predominantly marine food. This shift may well indicate a change in diet; the question left open by the limited initial isotop...
Ignacio H. Escapa; Juliana Sterli; Diego Pol; Laura Nicoli
2008-01-01
The plant and tetrapod fossil record of the Cañadón Asfalto Formation (Middle to Late Jurassic) found in Cerro Cóndor area (Chubut Province) is summarized here. The flora is dominated by conifers (Araucariaceae, Cupressaceae sensu lato) but also includes ferns and equisetaleans. The tetrapod fauna is composed of dinosaur taxa described in the 70's as well as other remains recently described and other vertebrate groups such as amphibians, turtles, and mammals. The amphibian remains have been i...
Directory of Open Access Journals (Sweden)
Elvira Latorre Blanco
2011-12-01
Full Text Available Se presenta una caracterización de 257 artefactos metálicos asignados a los períodos Intermedio Tardío y Tardío (ca. 900-1536 DC de la cultura Diaguita asentada en el norte semiárido de Chile. Los resultados indican un trabajo en metales centrado en el cobre o aleaciones con alto porcentaje de cobre, cuya manufactura se realizó mediante la deformación plástica en frío. Se propone un repertorio de 21 categorías morfológicas, de las cuales las más frecuentes corresponden a anzuelos de momentos preincaicos y ornamentos, especialmente aros, en el período Tardío. A partir de estos resultados, se discute tanto el impacto del dominio inca sobre la manufactura y uso de metales, así como aspectos relacionados con la producción y uso de metales por parte de las poblaciones diaguitas chilenas.This paper presents a characterization of 257 metal artifacts assigned to the Late Intermediate and Late periods (ca. 900-1536 AD of the Diaguita culture of semiarid northern Chile. The results indicate metalwork focused on copper, or alloys with a high percentage of copper, manufactured by cold plastic deformation. A repertoire of 21 morphological categories is proposed, the most frequent of which are pre-Inca fishhooks and ornaments, especially rings, in the Late Period. On the basis of these results we discuss the impact of Inca rule on the manufacture and use of metals, such as their production and use, by the Diaguita population.
Jurassic tetrapods and flora of Cañadón Asfalto Formation in Cerro Cóndor area, Chubut Province
Directory of Open Access Journals (Sweden)
Ignacio H. Escapa
2008-12-01
Full Text Available The plant and tetrapod fossil record of the Cañadón Asfalto Formation (Middle to Late Jurassic found in Cerro Cóndor area (Chubut Province is summarized here. The flora is dominated by conifers (Araucariaceae, Cupressaceae sensu lato but also includes ferns and equisetaleans. The tetrapod fauna is composed of dinosaur taxa described in the 70's as well as other remains recently described and other vertebrate groups such as amphibians, turtles, and mammals. The amphibian remains have been interpreted as representatives of a new species of Notobatrachus, considered one of the most basal members of the anuran lineage. Similarly, turtle remains have been recently recognized as a new species of basal turtle, bringing valuable information about the early evolution of this group. The dinosaur remains are largely dominated by saurischian taxa, represented by basal forms of Eusauropoda and Tetanurae. In addition, three different mammalian species have been identified and considered as early representatives of an endemic Gondwanan mammalian fauna. The fossil record of this formation represents the most completely known biota from the continental Middle to Late Jurassic of the Southern Hemisphere and one of the most complete of the entire world.
Directory of Open Access Journals (Sweden)
Nora Cabaleri
2010-05-01
Full Text Available El depocentro Cerro Cóndor representa la secuencia estratigráfica del Jurásico continental más completa de la cuenca de Cañadón Asfalto y de Sudamérica austral. Se sitúa en la Patagonia extraandina, en ambas márgenes del río Chubut medio. La sedimentación en esta cuenca pull apart, acompañada por efusiones de basalto olivínico, comenzó en el Jurásico Medio temprano. Predominan en la Formación Cañadón Asfalto los depósitos lacustres caracterizados por asociaciones de facies carbonáticas y siliciclásticas intercaladas con rocas lávicas en la base y depósitos piroclásticos hacia el techo de la unidad. Se describe el desarrollo de facies a lo largo de un corte norte-sur que abarca las secciones de estancia El Torito y de los cañadones Los Loros, Las Chacritas, Carrizal, Asfalto y Lahuincó. Las facies/microfacies carbonáticas están representadas por mudstones, wackestones,packstones, grainstones y calizas microbialíticas características de ambientes litorales, marginales y palustres. En la Formación Cañadón Asfalto se distinguen un miembro inferior (Las Chacritas, constituido por calizas, lutitas, areniscas y conglomerados, intercalados con basaltos olivínicos y por otro superior (Puesto Almada compuesto por tobas, tufitas, lutitas y areniscas. El primero es portador de una asociación palinológica de edad bajociano-bathoniana y el segundo de dinosaurios de edad tithoniana. Se describen detalladamente e ilustran las secciones estratigráficas de ambos miembros de la formación en sus localidades tipo, cañadón Las Chacritas y estancia el Torito y se reconstruyen los paleoambientes del depocentro desde el Aaleniano al Tithoniano. La edad del miembro Puesto Almada en su localidad tipo se obtuvo mediante una datación radimétrica (K/Ar de biotitas provenientes de una delgada capa de toba volcánica (147,1 ± 3,3 Ma, Tithoniano proveniente de la parte superior de la unidad.The Cerro Cóndor depocenter represents the
Densidad y distribución sobre CSMA/CA en redes IEEE 802.11g en modo AD HOC
Directory of Open Access Journals (Sweden)
José Domínguez
2010-09-01
Full Text Available El propósito principal de la presente investigación, fue determinar la influencia de la densidad y distribución de hosts sobre el control de acceso al medio en redes IEEE 802.11g, tomando como variables fundamentales la densidad y distribución de los mismos y el protocolo CSMA/CA para el acceso al medio de transmisión. La investigación fue de tipo explicativa, con un diseño experimental puro. La misma se basó en los postulados teóricos de Bates (2003, Comer (2000, León García (2001, Stallings (2005, Tanenbaum (2003, entre otros. El procedimiento a utilizar fue diseñado por el investigador y consistió de cuatro (04 fases: Enfoque teórico, experimentación, Recolección y análisis de los datos y elaboración de conclusiones y recomendaciones. La cantidad de hosts a utilizar en la red se ubicó en seis 06 equipos portátiles con especificaciones técnica similares. Para la recolección de la información se diseño un (1 instrumento, tipo formato de datos, en el cual se registraron diez (10 parámetros diferentes para evaluar el desempeño de la red en diversos escenarios. Seguidamente se tabularon los datos en cuadros, para proceder al análisis cuantitativo de los mismos. Se concluye que la densidad y distribución de los hosts en redes IEEE 802.11g afectan el acceso al medio de transmisión.Palabras clave: Densidad, distribución, red, ad hoc, control de acceso al medio.
Directory of Open Access Journals (Sweden)
Ignacio H. Escapa
2008-12-01
Full Text Available The plant and tetrapod fossil record of the Cañadón Asfalto Formation (Middle to Late Jurassic found in Cerro Cóndor area (Chubut Province is summarized here. The flora is dominated by conifers (Araucariaceae, Cupressaceae sensu lato but also includes ferns and equisetaleans. The tetrapod fauna is composed of dinosaur taxa described in the 70's as well as other remains recently described and other vertebrate groups such as amphibians, turtles, and mammals. The amphibian remains have been interpreted as representatives of a new species of Notobatrachus, considered one of the most basal members of the anuran lineage. Similarly, turtle remains have been recently recognized as a new species of basal turtle, bringing valuable information about the early evolution of this group. The dinosaur remains are largely dominated by saurischian taxa, represented by basal forms of Eusauropoda and Tetanurae. In addition, three different mammalian species have been identified and considered as early representatives of an endemic Gondwanan mammalian fauna. The fossil record of this formation represents the most completely known biota from the continental Middle to Late Jurassic of the Southern Hemisphere and one of the most complete of the entire world.Se resume brevemente el registro de plantas y tetrápodos fósiles de la Formación Cañadón Asfalto (Jurásico Medio a Superior en el área de Cerro Cóndor, provincia de Chubut. La flora está conformada por coníferas de las familias Araucariaceae y Cupressaceae sensu lato dominando la asociación, la cual se completa con helechos y equisetales en proporciones menores. La fauna de tetrápodos se compone por los clásicos dinosaurios descriptos en los 70`s, a los que se suman nuevos restos pertenecientes a este grupo, así como anfibios, tortugas y mamíferos coleccionados en la última década. Los restos de anfibios han sido interpretados como representantes de una nueva especie de Notobatrachus, considerado
Directory of Open Access Journals (Sweden)
Nora Cabaleri
2010-05-01
Full Text Available El depocentro Cerro Cóndor representa la secuencia estratigráfica del Jurásico continental más completa de la cuenca de Cañadón Asfalto y de Sudamérica austral. Se sitúa en la Patagonia extraandina, en ambas márgenes del río Chubut medio. La sedimentación en esta cuenca pull apart, acompañada por efusiones de basalto olivínico, comenzó en el Jurásico Medio temprano. Predominan en la Formación Cañadón Asfalto los depósitos lacustres caracterizados por asociaciones de facies carbonáticas y siliciclásticas intercaladas con rocas lávicas en la base y depósitos piroclásticos hacia el techo de la unidad. Se describe el desarrollo de facies a lo largo de un corte norte-sur que abarca las secciones de estancia El Torito y de los cañadones Los Loros, Las Chacritas, Carrizal, Asfalto y Lahuincó. Las facies/microfacies carbonáticas están representadas por mudstones, wackestones,packstones, grainstones y calizas microbialíticas características de ambientes litorales, marginales y palustres. En la Formación Cañadón Asfalto se distinguen un miembro inferior (Las Chacritas, constituido por calizas, lutitas, areniscas y conglomerados, intercalados con basaltos olivínicos y por otro superior (Puesto Almada compuesto por tobas, tufitas, lutitas y areniscas. El primero es portador de una asociación palinológica de edad bajociano-bathoniana y el segundo de dinosaurios de edad tithoniana. Se describen detalladamente e ilustran las secciones estratigráficas de ambos miembros de la formación en sus localidades tipo, cañadón Las Chacritas y estancia el Torito y se reconstruyen los paleoambientes del depocentro desde el Aaleniano al Tithoniano. La edad del miembro Puesto Almada en su localidad tipo se obtuvo mediante una datación radimétrica (K/Ar de biotitas provenientes de una delgada capa de toba volcánica (147,1 ± 3,3 Ma, Tithoniano proveniente de la parte superior de la unidad.
Directory of Open Access Journals (Sweden)
Durán Barceló, Javier
2012-01-01
Full Text Available Aunque ya estaba catalogado desde 1745 y de nuevo en 1800, los modernos estudiosos no tuvieron noticia de la existencia de este manuscrito del siglo XV de Alfonso de Palencia hasta que Bartolomé José Gallardo lo describió. Gallardo describe el manuscrito Ad Alfonsum de Velasco in funebrem Abulensis praesulis cuando éste se encontraba a modo de préstamo en la Real Academia de la Historia, en Madrid, a mediados del siglo XIX. En aquella época la RAH procuraba la publicación de las obras de Alfonso de Palencia y seguramente a aquellos esfuerzos se debe que se conserve actualmente en la RAH una copia moderna de este manuscrito medieval, el cual fue devuelto a su propietaria. La primera edición del texto la hicieron en 1982 Brian Tate y Rafael Alemany Ferrer basándose para ello en la copia decimonónica. Pues, dado que Gallardo había dado una información confusa acerca de la localización del manuscrito medieval, los modernos editores no pudieron localizarlo. Este trabajo resuelve finalmente el problema de la localización del manuscrito original, conservado en la Universidad Complutense de Madrid. Gracias a este hallazgo mi edición del texto se basa directamente en el original medieval sobre el que intento dilucidar algunas lecturas difícilesAlthough it had been catalogued in 1745 and again in 1800, it was not until Bartolomé José Gallardo reported the existence of this 15th century manuscript of Alfonso de Palencia when scholars became aware of its existence. Gallardo described the manuscript Ad Alfonsum de Velasco in funebrem Abulensis praesulis when it was borrowed by the Royal Academy of History, in Madrid, in mid 19th century. At that time the Academy was involved in the edition of the works of Alfonso de Palencia and for this reason a hand written copy of the medieval manuscript remained in the Academy, while the original was returned to its owner. Based on this 19th century copy, Brian Tate and Rafael Alemany Ferrer published
Commendador, Amy S; Dudgeon, John V; Finney, Bruce P; Fuller, Benjamin T; Esh, Kelley S
2013-10-01
Ecological and environmental evidence suggests that Rapa Nui was among the most marginally habitable islands in Eastern Polynesia, with only a fraction of the biotic diversity found on archipelagos to the west, and capable of sustaining many fewer cultigens traditionally transported by Polynesian colonizers. However, archaeological evidence for human dietary adaptations under such restrictions is limited. Little is known about the particulars of the subsistence base and dietary changes on Rapa Nui that may be associated with a hypothesized late prehistoric decline in the quality and diversity of food sources. To better understand prehistoric Rapa Nui diet we examined stable carbon and nitrogen isotope compositions of human teeth along with archaeological faunal material thought to comprise the Rapa Nui food web. Our results indicate that contrary to previous zooarchaeological studies diet was predominantly terrestrial throughout the entire sequence of occupation, with reliance on rats, chickens and C3 plants. While a few individuals may have had access to higher trophic level marine resources, this is evident only later in time (generally post-AD 1600). A decline in (15)N through time was observed, and may be attributed to declines in available terrestrial proteins; however, presently we cannot rule out the effect of changing soil and plant baseline δ(15)N. Our results also suggest differential access to higher trophic level marine resources among contemporaneous populations, but more research is required to clarify this observation. PMID:23996514
Anabalon, Andres; Choque, David
2016-01-01
We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We discuss the role of these solutions for the existence of first order phase transitions for planar hairy black holes within these theories.
In, Chi-Seung; Yeo, Dong-Hun; Shin, Hyo-Soon; Nahm, Sahn; Choi, Won-Youl
2015-04-01
In accordance with the trend for mobile terminals to be high intensity and to have thinner layers, low temperature co-fired ceramics (LTCC) materials with outstanding dielectric loss characteristics and diverse dielectric constants have been in demand, and the need for high-strength materials that can withstand external shocks has increased. Ca[(Li1/3Nb2/3)1- x Ti x ]O3- δ (CLNT) has a quality factor over 14,000 and τ f ≤ 10 when the dielectric constant is 41 ˜ 46, but its sintering temperature is high at 1150 °C. Therefore, it cannot be used as a LTCC component. This study aimed to lower the sintering temperature to 900 °C by adding a low-melting-point glass such as B2O3·SiO2·BaO and B2O3·SiO2·Al2O3. As the glass content in CLNT was increased from 10 wt% to 20 wt%, the density and the Q·f0 property decreased, and the dielectric constant rose. When B2O3·SiO2·BaO was added to CLNT at 15 wt%, the dielectric constant was found to be 27, the Q·f0 property to be 3470, and the τ f to be -18 ppm/°C. When B2O3·SiO2·Al2O3 was added to CLNT at 10 wt%, the dielectric constant was 20, the Q·f0 property was 3990, and the τ f was -15 ppm/°C. As such, in both cases, excellent dielectric properties were observed.
... Restaurant Deciphering the Menu Ordering Your Meal Eating Fast Food Dining Out Tips by Cuisine Physical Activity Fitness ... Learn more about reading food labels . Limit your consumption of foods with high amounts of added sugars, ...
Maldacena, Juan; Maoz, Liat
2004-01-01
We construct a few Euclidean supergravity solutions with multiple boundaries. We consider examples where the corresponding boundary field theory is well defined on each boundary. We point out that these configurations are puzzling from the AdS/CFT point of view. A proper understanding of the AdS/CFT dictionary for these cases might yield some information about the physics of closed universes.
Complexity Growth for AdS Black Holes
Cai, Rong-Gen; Wang, Shao-Jiang; Yang, Run-Qiu; Peng, Rong-Hui
2016-01-01
We further investigate the Complexity-Action (CA) duality conjecture for stationary anti de-Sitter (AdS) black holes and derive some exact results for the growth rate of action within Wheeler-DeWitt (WDW) patch at late time approximation, which is dual to the growth rate of quantum complexity of holographic state. Based on the results from the general $D$-dimensional Reissner-Nordstr\\"{o}m (RN)-AdS black hole, rotating/charged Ba\\~{n}ados-Teitelboim-Zanelli (BTZ) black hole, Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a new complexity bound but leave unchanged the conjecture that the stationary AdS black hole in Einstein gravity is the fastest computer in nature.
Powers, Shelley
2007-01-01
Ajax can bring many advantages to an existing web application without forcing you to redo the whole thing. This book explains how you can add Ajax to enhance, rather than replace, the way your application works. For instance, if you have a traditional web application based on submitting a form to update a table, you can enhance it by adding the capability to update the table with changes to the form fields, without actually having to submit the form. That's just one example.Adding Ajax is for those of you more interested in extending existing applications than in creating Rich Internet Applica
Electrodeposition of Ca Metal in CaCl2-CaO Molten Salt
Institute of Scientific and Technical Information of China (English)
GUO; Jun-kang; WANG; Chang-shui; CAO; Long-hao; OUYANG; Ying-gen
2013-01-01
To realize the continuouscalciothermic reduction in molten salts,the electrodeposition behavior of Ca metal in CaCl2-CaO molten salt was investigated by cylic voltammetry.The cyclic voltammograms at the scan rate of 100 mV/s are shown in Fig.1.As is shown,the electrodeposition potential of Ca deviated from-1.66 V to-0.97 V after CaO was added to molten CaCl2 and the decomposition of CaO
María Soledad Gheggi; Verónica Isabel Williams
2013-01-01
We present data on carbon and nitrogen isotopic composition of human bones from Tolombón (Calchaqui Valley, Salta) and Esquina de Huajra (Quebrada de Humahuaca, Jujuy) sites located in Northwest Argentina (NWA). Both are complex archaeological residential settlements ascribed to the Regional Development Period (ca. 900–1430 A.D.), the Inca Period (ca. 1430–1536 A.D.), and the Early Colonial Period (ca. 1536–1600 A.D.). Twelve samples of human bones were collected and analyzed, including remai...
Liu, Lijuan; Cui, Mingqi; Hu, Yongfeng; Zheng, Lei; Zhao, Yidong; Ma, Chenyan; Xi, Shibo; Yang, Dongliang; Guo, Zhiying; Wang, Jie
2012-01-01
This work is concerned with the Ca transformations during the pyrolysis of Ca(OH)2 or CaCO3-added coals. Ca K-edge X-ray absorption near edge structure (XANES) spectroscopy was applied to determine the forms of Ca in chars prepared from the pyrolysis of Ca-added coal. Results showed that Ca(OH)2 and CaSO4 existed in both the Ca(OH)2-added chars and the CaCO3-added chars, while CaS and CaO only existed in the chars prepared from the Ca(OH)2-added coal. Moreover, it was found that carboxyl Ca was formed during pyrolysis for either the Ca(OH)2-added coal or the CaCO3-added coals.
Directory of Open Access Journals (Sweden)
María Soledad Gheggi
2013-01-01
Full Text Available We present data on carbon and nitrogen isotopic composition of human bones from Tolombón (Calchaqui Valley, Salta and Esquina de Huajra (Quebrada de Humahuaca, Jujuy sites located in Northwest Argentina (NWA. Both are complex archaeological residential settlements ascribed to the Regional Development Period (ca. 900–1430 A.D., the Inca Period (ca. 1430–1536 A.D., and the Early Colonial Period (ca. 1536–1600 A.D.. Twelve samples of human bones were collected and analyzed, including remains from individuals of both sexes and different ages at death. We also present the carbon and nitrogen isotopic composition of modern plants from nearby areas in order to start building an isotopic ecology of the area and compile available information on food consumption from different lines of evidence. The isotopic results obtained reveal the consumption of C4 plants, which for the area are maize and amaranth, combined with animal proteins. The integration of these results with the broader database was useful to discuss the political and economical implications of the findings, especially in the context of this area under the Inca domination.
Online Ad Assignment with an Ad Exchange
Dvořák, Wolfgang; Henzinger, Monika
2016-01-01
Ad exchanges are becoming an increasingly popular way to sell advertisement slots on the internet. An ad exchange is basically a spot market for ad impressions. A publisher who has already signed contracts reserving advertisement impressions on his pages can choose between assigning a new ad impression for a new page view to a contracted advertiser or to sell it at an ad exchange. This leads to an online revenue maximization problem for the publisher. Given a new impression to sell decide whe...
Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.
2016-06-01
We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.
Costa, Miguel S; Oliveira, Miguel; Penedones, João; Santos, Jorge E
2015-01-01
We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global $AdS_{4}$ with conformal boundary $S^{2}\\times\\mathbb{R}_{t}$. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic $AdS$ behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an $AdS$ soliton that includes the full backreaction of the electric field on the $AdS$ geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both $AdS$ soliton and black hole phases. The corresponding phase diagram generalizes the Hawkin...
Indian Academy of Sciences (India)
S N Ekbote; G K Padam; M Sharma; N K Arora; B S Khurana; R C Goel; D K Suri; N Mehra; B K Das
2001-12-01
Bulk tube conductors of Bi1.84Pb0.4Sr2Ca2.2Cu3O10+ with addition of silver varying from 0 to 25 wt% (not reported earlier) were systematically studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), electrical transport and a.c. susceptibility techniques. The tube conductors formed by cold isostatic pressing (CIP) of the powders obtained from spray drying method have been made successfully. It was found that Ag addition has not only affected the formation of the desired Bi-2223 phase and the microstructure of these large bulk tube samples thereby influencing on the critical current (c), it also reduces the contact resistance to minimize the cryogen losses. These variations have been found to be Ag content dependent. An optimized value of 10 wt% Ag has been found to produce the best quality tubes showing reproducible c value > 120 Amp at 77 K which is in general a requirement to energies of the cryogen free conventional/HTSC superconducting magnets below 20 K.
Institute of Scientific and Technical Information of China (English)
王海涛
2005-01-01
首先介绍了Ad Hoc网络的基本概念、技术特点以及关键技术等,然后较为全面地归纳了Ad Hoc网络的典型应用,最后讨论了Ad Hoc网络的发展趋势和有待解决的问题.
Elliot-Ripley, Matthew; Winyard, Thomas
2015-01-01
We study the baby Skyrme model in a pure AdS background without a mass term. The tail decays and scalings of massless radial solutions are demonstrated to take a similar form to those of the massive flat space model, with the AdS curvature playing a similar role to the flat space pion mass. We also numerically find minimal energy solutions for a range of higher topological charges and find that they form concentric ring-like solutions. Popcorn transitions (named in analogy with studies of toy...
Maldacena, Juan M.
2001-01-01
We propose a dual non-perturbative description for maximally extended Schwarzschild Anti-de-Sitter spacetimes. The description involves two copies of the conformal field theory associated to the AdS spacetime and an initial entangled state. In this context we also discuss a version of the information loss paradox and its resolution.
Current status of AdS instability
CERN. Geneva
2016-01-01
arXiv:1403.6471 and thoroughly developed in arXiv:1407.6273. On the other hand the negative cosmological constant allows for the existence of stable, time-periodic, asymptotically AdS solutions of Einstein equations [arXiv:1303.3186].
AdS braneworld with Backreaction
Bilic, Neven
2014-01-01
We review the tachyon model derived from the dynamics of a 3-brane moving in the AdS5 bulk. The bulk geometry is based on the Randall-Sundrum II model extended to include the radion. The effective tachyon Lagrangian is modified due to the back-reaction of the brane on the bulk geometry.
Superradiant instability in AdS
Ganchev, Bogdan
2016-01-01
The phenomenon of superradiance in the context of asymptotically global AdS spacetimes is investigated with particular accent on its effect on the stability of the systems under consideration. To this end, the concept of an asymptotically AdS spacetime is explained, together with its implications on the boundary conditions at $\\mathcal{I}$, as well as the Newman-Penrose-Teukolsky formalism, whereby the Teukolsky master equation in a most general form for Kerr-AdS is given. Furthermore, work done in the cases of RN-AdS and Kerr-AdS is laid out in a concise manner, putting emphasis on the important steps taken in determining the endpoint of the superradiant instability in the two configurations. For the former this turns out to be a black hole with reduced charge and a static charged scalar condensate around it, whereas for the latter two of the more probable outcomes are presented, both of which imply a violation of one of the cosmic censorships.
Instability corners in AdS space
Dimitrakopoulos, Fotios V; Lippert, Matthew; Yang, I-Sheng
2014-01-01
We investigate whether arbitrarily small perturbations in global AdS space are generically unstable and collapse into black holes on the time scale set by gravitational interactions. We argue that current evidence, combined with our analysis, strongly suggests that a set of nonzero measure in the space of initial conditions does not collapse on this time scale. On the other hand, existing results do not provide an equally strong indication whether the unstable solutions also form a set of nonzero measure. We perform an analysis in position space to address this puzzle, and our formalism allows us to directly address the vanishing-amplitude limit. We show that gravitational self-interaction leads to tidal deformations which are equally likely to focus or defocus energy, and we sketch the phase diagram accordingly. We also clarify the connection between gravitational evolution in global AdS and holographic thermalization.
Elliot-Ripley, Matthew
2015-01-01
We study the baby Skyrme model in a pure AdS background without a mass term. The tail decays and scalings of massless radial solutions are demonstrated to take a similar form to those of the massive flat space model, with the AdS curvature playing a similar role to the flat space pion mass. We also numerically find minimal energy solutions for a range of higher topological charges and find that they form concentric ring-like solutions. Popcorn transitions (named in analogy with studies of toy models of holographic QCD) from an n layer to an n+1-layer configuration are observed at topological charges 9 and 27 and further popcorn transitions for higher charges are predicted. Finally, a point-particle approximation for the model is derived and used to successfully predict the ring structures and popcorn transitions for higher charge solitons.
AdS solutions through transgression
Energy Technology Data Exchange (ETDEWEB)
Donos, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Gauntlett, J.P. [Imperial College, London (United Kingdom). Blackett Lab.]|[Imperial College, London (United Kingdom). The Institute for Mathematical Sciences; Kim, Nakwoo [Kyung Hee Univ., Seoul (Korea). Dept. of Physics and Research Inst. of Basic Science
2008-07-15
We present new classes of explicit supersymmetric AdS{sub 3} solutions of type IIB supergravity with non-vanishing five-form flux and AdS{sub 2} solutions of D=11 supergravity with electric four-form flux. The former are dual to two-dimensional SCFTs with (0,2) supersymmetry and the latter to supersymmetric quantum mechanics with two supercharges. We also investigate more general classes of AdS{sub 3} solutions of type IIB supergravity and AdS{sub 2} solutions of D=11 supergravity which in addition have non-vanishing three-form flux and magnetic four-form flux, respectively. The construction of these more general solutions makes essential use of the Chern-Simons or ''transgression'' terms in the Bianchi identity or the equation of motion of the field strengths in the supergravity theories. We construct infinite new classes of explicit examples and for some of the type IIB solutions determine the central charge of the dual SCFTs. The type IIB solutions with non-vanishing three-form flux that we construct include a two-torus, and after two T-dualities and an S-duality, we obtain new AdS3 solutions with only the NS fields being non-trivial. (orig.)
LATS refining ladle slag modifying with CaO-CaF2
Institute of Scientific and Technical Information of China (English)
Hongming Wang; Guirong Li; Zhongming Ren; Bo Li; Xuejun Zhang; Guomin Shi
2007-01-01
To reduce the slag sticking onto the snorkel of the ladle during the ladle alloying treatment station (LATS) process, CaO-CaF2 (the mass ratio of CaO/CaF2 is 1:1) was employed as the modifier of the LATS refining ladle slag. The effect of CaO-CaF2 on the melting point, viscosity, and desulfurizing capability of the ladle slag was investigated. The melting point of the unmodified ladle slag is 1439°C. When adding 20wt% CaO-CaF2, the melting point is decreased to 1327°C. At 1500°C, the viscosity of the unmodified ladle slag is 6.5 Pa·s, which can be decreased lower than 2 Pa·s by adding more than 10wt% CaO-CaF2. The experimental results of desulfurization of the melts show that the desulfurizing power of the ladle slag can be enhanced by adding CaO-CaF2.
Refined Holographic Entanglement Entropy for the AdS Solitons and AdS black Holes
Ishihara, Masafumi; Ning, Bo
2012-01-01
We consider the refinement of the holographic entanglement entropy on a disk region for the holographic dual theories to the AdS solitons and AdS black holes, including the corrected ones by the Gauss-Bonnet term. The AdS soliton is dual to a gapped system with an IR fixed-point. The refinement is obtained by extracting the UV-independent piece of the holographic entanglement entropy. We then study the renormalization group (RG) flow of the refinement by tuning the linear size of the chosen disk region. Our main results are (i) the RG flow of the refinement decreases monotonically for most of the cases; (ii) there is no topological entanglement entropy for AdS$_5$ soliton even with Gauss-Bonnet correction; (iii) for the AdS black holes, the refinement obeys the volume law at IR regime, and the transition between UV and IR regimes is a smooth crossover; however, the crossover will turn into phase transition by the Gauss-Bonnet correction; (iv) for the AdS solitons, there are discontinuous phase transitions bet...
Refined holographic entanglement entropy for the AdS solitons and AdS black holes
International Nuclear Information System (INIS)
We consider the refinement of the holographic entanglement entropy for the holographic dual theories to the AdS solitons and AdS black holes, including the corrected ones by the Gauss–Bonnet term. The refinement is obtained by extracting the UV-independent piece of the holographic entanglement entropy, the so-called renormalized entanglement entropy which is independent of the choices of UV cutoff. Our main results are: (i) the renormalized entanglement entropies of the AdSd+1 soliton for d=4,5 are neither monotonically decreasing along the RG flow nor positive-definite, especially around the deconfinement/confinement phase transition; (ii) there is no topological entanglement entropy for AdS5 soliton even with Gauss–Bonnet correction; (iii) for the AdS black holes, the renormalized entanglement entropy obeys an expected volume law at IR regime, and the transition between UV and IR regimes is a smooth crossover even with Gauss–Bonnet correction; (iv) based on AdS/MERA conjecture, we postulate that the IR fixed-point state for the non-extremal AdS soliton is a trivial product state
DEFF Research Database (Denmark)
Liu, Yawu; Mattila, Jussi; Ruiz, Miguel �ngel Mu�oz;
2013-01-01
To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool) and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA) on MRI...
Minces, P; Minces, Pablo; Nunez, Carmen
2006-01-01
Correlation functions of one-unit spectral flowed states in string theory on AdS_3 are considered. We present a formalism which allows to explicitly find the modified Knizhnik-Zamolodchikov and null vector equations to be satisfied by amplitudes of states in w=1 sectors. We give a precise prescription to solve this system of linear differential equations in cases that are relevant to obtain three and four point functions involving spectral flowed string states. We specifically compute three point functions with two and three one-unit spectral flowed operators and also discuss four point functions.
Institute of Scientific and Technical Information of China (English)
李丛言; 盛宝英; 韩凤; 齐志国; 张瑞雪
2015-01-01
目的 研究胱氨酸干预下AD模型鼠海马CA1区神经干细胞凋亡影响因子NPM的表达变化情况.方法 取Wistar大鼠66只,随机分为正常组、AD模型组与胱氨酸治疗组,规定ld、3d、7d、14 d、21 d5个测定时间点,利用免疫印迹法及PCR方法测定NPM因子的表达情况,TUNEL细胞凋亡检测法测定各组大鼠细胞凋亡数.结果 进行实验3d后,NPM的表达开始升高(P＜0.01),具有统计意义,并于14 d达到峰值,且胱氨酸治疗组AD模型鼠的NPM表达始终高于AD模型组AD模型鼠.参与实验的大鼠实验开始3d后细胞凋亡数明显增加并于14 d达到峰值,但胱氨酸治疗组大鼠的细胞凋亡数始终低于AD模型组.结论 胱氨酸可以抑制AD致伤的神经干细胞的凋亡,其促进NPM因子表达上调可能是其抑制细胞凋亡的机制之一.
DEFF Research Database (Denmark)
Jensen, Per Anker; Katchamart, Akarapong
2011-01-01
Purpose: To investigate how Facilities Management (FM) can add value and develop a management concept that can assist facilities managers in implementing value adding strategies and practices. Theory: The study is based on the management model for FM included in the European FM standards, recent...... theories on added value of FM and real estate and the related concept of Value Management from building projects. The study is related to the EuroFM research group on The Added Value of FM. Design/methodology/approach: The study outlines a preliminary theoretical based management concept, which...... the relevance of the basic concept and provides an important example of how Value Adding Management can be implemented and added value measured. Originality/value: The study develops a concept of Value Adding Management, which is new in FM literature. It is expected to increase the awareness of the impacts...
Bena, Iosif; Heurtier, Lucien; Puhm, Andrea
2016-05-01
It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.
Adamo, Tim; Williams, Jack
2016-01-01
We consider the application of twistor theory to five-dimensional anti-de Sitter space. The twistor space of AdS$_5$ is the same as the ambitwistor space of the four-dimensional conformal boundary; the geometry of this correspondence is reviewed for both the bulk and boundary. A Penrose transform allows us to describe free bulk fields, with or without mass, in terms of data on twistor space. Explicit representatives for the bulk-to-boundary propagators of scalars and spinors are constructed, along with twistor action functionals for the free theories. Evaluating these twistor actions on bulk-to-boundary propagators is shown to produce the correct two-point functions.
Low energy 40Ca + 40Ca collisions
International Nuclear Information System (INIS)
This paper deals with the classical microscopic study of 40Ca + 40Ca collisions. Fusion cross-sections (σsub(CF)) for various incident energies, energy variations with time, shape deformation and the life time of resonance scattering (T) have been studied. Comparison of 40Ca + 40Ca results with those of 16O + 16O have also been made. (author)
ADS National Programmes: India
International Nuclear Information System (INIS)
Initial preliminary studies in India on ADS concepts were aimed toward applications such as, one way coupled booster reactor concept, thorium burner concept, enhancement of breeding rate of thorium– fueled fast reactors, and to incinerate Pu and minor actinides discharged from heavy water and fast reactors. These studies led to a roadmap on development of ADS subsystems in India, which was chalked out initially in June 2001. It was realized in these studies that the most challenging subsystem in terms of technology development and capital investment for ADS in India would be the high intensity proton accelerator, and that it must be accomplished in phased manner. Of the two alternative accelerator types, viz. the cyclotron and linear accelerator (linac), it is concluded that only linac would provide the necessary intense beam current for ADS applications. The energy amplifier (EA) scheme, with lead (45.5%) bismuth (55.5%) eutectic (LBE) as target & coolant, which was proposed in the early nineties would be one of the desired configurations of ADS for Indian applications. Additionally, subcritical reactor core of Indian Advanced Heavy Water Reactor (AHWR), with advantages of its low fission power density, and neutron economy is also a candidate among various ADS reactor configurations. These options of ADS configurations for thorium utilization are based on the neutronic properties of 233U isotope as fissile fuel, which are more or less similar in thermal and in moderately fast neutron spectra
Institute of Scientific and Technical Information of China (English)
周源; 李志刚; 周阿剑; 姜婧; 王鑫; 韩向博; 朴赞勋; 宋萌
2015-01-01
目的:探讨音乐电针是否通过减少β淀粉样蛋白1-42(Aβ1-42)的表达,改善阿尔茨海默病(AD)模型快速老化小鼠亚系(SAMP8)小鼠学习记忆行为能力.方法:将20只8月龄SAMP8雄性鼠随机分为模型组、音乐电针组,每组各10只,另设10只抗快速老化小鼠亚系(SAMR1)雄性鼠为正常对照组.音乐电针组针刺百会、印堂后,穴位接人音乐电针仪,选用节奏明朗、速度与力度适中的音乐处方,调节强度以使动物不挣扎嘶叫保持安静为度,每次20 min,1次/d,共15 d;正常组、模型组用相同方法每天用鼠袋束缚20 min.以Moms水迷宫检测小鼠学习记忆能力,免疫组织化学法检测小鼠海马CA3区Aβ1-42表达的影响.结果:Morrs水迷宫检测显示,模型组逃避潜伏期较正常组增加、空间探索实践穿越平台次数减少,靶象限路程占总路程之比明显减少;音乐电针组逃避潜伏期较模型组减少、空间探索实验穿越平台次数增多,靶象限路程占总路程之比明显增多.免疫组化检测显示,正常组的阳性细胞数量少,着色浅;模型组的阳性细胞较正常组明显增多,染色深;音乐电针组的阳性细胞及颜色介于正常组和模型组之间.结论:音乐电针治疗能减少SAMP8小鼠CA3区Aβ1-42的表达,同时能提高AD模型小鼠的学习记忆能力.
John Wiley & Sons
2004-01-01
"Assimilating the most up-to-date information on research and development activities in this rapidly growing area, Mobile Ad Hoc Networking covers physical, data link, network, and transport layers, as well as application, security, simulation, and power management issues in sensor, local area, personal, and mobile ad hoc networks. Each of the book's sixteen chapters has been written by a top expert and discusses in-depth the most important topics in the field. Mobile Ad Hoc Networking is an excellent reference and guide for professionals seeking an in-depth examination of topics that also provides a comprehensive overview of the current state-of-the-art."--Jacket.
Hoy, Darrell; Jain, Kamal; Wilkens, Christopher A.
2012-01-01
A single advertisement often benefits many parties, for example, an ad for a Samsung laptop benefits Microsoft. We study this phenomenon in search advertising auctions and show that standard solutions, including the status quo ignorance of mutual benefit and a benefit-aware Vickrey-Clarke-Groves mechanism, perform poorly. In contrast, we show that an appropriate first-price auction has nice equilibria in a single-slot ad auction --- all equilibria that satisfy a natural cooperative envy-freen...
Bena, Iosif; Puhm, Andrea
2015-01-01
It was argued in arXiv:1203.4227 that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically-AdS_3 x S^3/Z_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.
ADS National Programmes: Italy
International Nuclear Information System (INIS)
Following a preliminary design developed in 1998, based on the Energy Amplifier concept proposed by CERN, a first configuration of a lead-bismuth Eutectic cooled Experimental ADS (LBE-XADS) was worked out in the period 1999–2001, under the aegis of MURST, by a group of Italian organizations led by Ansado Nucleare, with the aim of assessing the feasibility of a small sized (80 MWth) ADS. At the end of 1997 a joint effort of ENEA (National Agency for New Technology, Energy and the Environment) and INFN (National Institute for Nuclear Physics) led to the approval of a national programme by MURST (Minister for University and Scientific and Technological Research) named TRASCO (TRAsmutazione SCOrie) aiming at the study of physics and technologies needed to design an ADS for radioactive waste transmutation. The programme consisted of research subprogrammes on accelerator, neutronics, thermalhydraulics analysis, beam window technology, and material technology and compatibility with Pb and Pb-Bi. At now, most of the activities in support to the ADS development carried out at national level are part of EU-funded Projects. These activities are complemented by the programme agreement (AdP -Accordo di programma), signed between ENEA and the Ministry of Economic Development, which provides in general a range of activities aimed at the development of sustainable nuclear fission systems. Several universities and the national industry are involved, besides ENEA, in the activities
ADS National Programmes: China
International Nuclear Information System (INIS)
In China the conceptual study of an ADS concept which lasted for about five years ended in 1999. As one project of the National Basic Research Programme of China (973 Programme) in energy domain, which is sponsored by the China Ministry of Science and Technology (MOST), a five year programme of fundamental research of ADS physics and related technology was launched in 2000 and passed national review at the end of 2005. From 2007, another five year 973 Programme Key Technology Research of Accelerator Driven Subcritical System for Nuclear waste Transmutation started. The research activities were focused on HPPA physics and technology, reactor physics of external source driven subcritical assembly, nuclear data base and material study. For HPPA, a high current injector consisting of an ECR ion source, LEBT and an RFQ accelerating structure of 3.5 MeV has been built and were being improved. In reactor physics study, a series of neutron multiplication experimental study has been carrying out. The VENUS I facility has been constructed as the basic experimental platform for neutronics study in ADS blanket. VENUS I a zero power subcritical neutron multiplying assembly driven by external neutron produced by a pulsed neutron generator or 252Cf neutron source. The theoretical, experimental and simulation studies on nuclear data, material properties and nuclear fuel circulation related to ADS are carried out in order to provide the database for ADS system analysis. China Institute of Atomic Energy (CIAE), Institute of High Energy Physics (IHEP) and other Chinese institutes carried out the MOST project together. Besides CIAE, China Academy of Science (CAS) pays more and more attention to Advanced Nuclear Fuel Cycles (ANFC). A large programme of ANFC, including ADS and Th based nuclear fuel cycle, has been launched by CAS
Rashvand, Habib
2013-01-01
Motivated by the exciting new application paradigm of using amalgamated technologies of the Internet and wireless, the next generation communication networks (also called 'ubiquitous', 'complex' and 'unstructured' networking) are changing the way we develop and apply our future systems and services at home and on local, national and global scales. Whatever the interconnection - a WiMAX enabled networked mobile vehicle, MEMS or nanotechnology enabled distributed sensor systems, Vehicular Ad hoc Networking (VANET) or Mobile Ad hoc Networking (MANET) - all can be classified under new networking s
DEFF Research Database (Denmark)
Hillersdal, Line
in the context of the 'ad libitum meal'. The analytical interest is thus what kind of eaters and bodies are enacted in the meal test and what ideas of prevention and treatment are embedded in their standards. Drawing from ongoing empirical work among Danish obesity researchers performing scientific meal tests I...... ask what make up food stuff and eaters in the meal tests? More specifically I explore a scientific testing of changes in taste preferences before and after weight-loss surgery using an ad libitum buffet with a selection of different foods and another testing the effect of exercise on appetite also...
ADS National Programmes: Belgium
International Nuclear Information System (INIS)
The Belgian activities in the field of Accelerator Driven Systems (ADS) are mainly related to the MYRRHA project development. MYRRHA is an accelerator driven, multi purpose fast neutron spectrum facility for R&D, cooled by a lead-bismuth eutectic. SCK•CEN has started the MYRRHA project as a national programme with several national & international bilateral collaboration agreements; the project has now evolved as an European integrated project in the frame of the IPEUROTRANS (European Commission, Sixth Framework Programme). The MYRRHA ‘Draft-2’ predesign file (completed in the early 2005) has been proposed to the partners as a basis for the XT-ADS machine. After a detailed investigation of potential alternatives, the MYRRHA concept (for the subcritical core, the primary coolant system, the accommodation of experimental rigs, the reactor vessel and the spallation target) has been kept with some modifications to achieve the XT-ADS objectives. The most recent version of the XT-ADS design was presented in the 2007 TWG meeting
Israel, D
2005-01-01
We study the exact construction of D-branes in Lorentzian AdS(3). We start by defining a family of conformal field theories that gives a natural Euclidean version of the SL(2,R) CFT and does not correspond to H(3)+, the analytic continuation of AdS(3). We argue that one can recuperate the exact CFT results of Lorentzian AdS(3), upon an analytic continuation in the moduli space of these conformal field theories. Then we construct exact boundary states for various symmetric and symmetry-breaking D-branes in AdS(3).
Localization on $AdS_2\\times S^1$
David, Justin R; Gupta, Rajesh Kumar; Narain, Kumar
2016-01-01
Conformal symmetry relates the metric on $AdS_2 \\times S^{1}$ to that of $S^3$. This implies that under a suitable choice of boundary conditions for fields on $AdS_2$ the partition function of conformal field theories on these spaces must agree which makes $AdS_2 \\times S^{1}$ a good testing ground to study localization on non-compact spaces. We study supersymmetry on $AdS_2\\times S^1$ and determine the localizing Lagrangian for ${\\cal N}=2$ supersymmetric Chern-Simons theory on $AdS_2\\times S^1$. We evaluate the partition function of ${\\cal N}=2$ supersymmetric Chern-Simons theory on $AdS_2 \\times S^1$ using localization, where the radius of $S^1$ is $q$ times that of $AdS_2$. With boundary conditions on $AdS_2\\times S^1$ which ensure that all the physical fields are normalizable and lie in the space of square integrable wave functions in $AdS_2$, the result for the partition function precisely agrees with that of the theory on the $q$-fold covering of $S^3$.
Biphasic decay of the Ca transient results from increased sarcoplasmic reticulum Ca leak
Sankaranarayanan, Rajiv; Li, Yatong; Greensmith, David J.; Eisner, David A.
2016-01-01
Key points Ca leak from the sarcoplasmic reticulum through the ryanodine receptor (RyR) reduces the amplitude of the Ca transient and slows its rate of decay.In the presence of β‐adrenergic stimulation, RyR‐mediated Ca leak produces a biphasic decay of the Ca transient with a fast early phase and a slow late phase.Two forms of Ca leak have been studied, Ca‐sensitising (induced by caffeine) and non‐sensitising (induced by ryanodine) and both induce biphasic decay of the Ca transient.Only Ca‐sensitising leak can be reversed by traditional RyR inhibitors such as tetracaine.Ca leak can also induce Ca waves. At low levels of leak, waves occur. As leak is increased, first biphasic decay and then slowed monophasic decay is seen. The level of leak has major effects on the shape of the Ca transient. Abstract In heart failure, a reduction in Ca transient amplitude and contractile dysfunction can by caused by Ca leak through the sarcoplasmic reticulum (SR) Ca channel (ryanodine receptor, RyR) and/or decreased activity of the SR Ca ATPase (SERCA). We have characterised the effects of two forms of Ca leak (Ca‐sensitising and non‐sensitising) on calcium cycling and compared with those of SERCA inhibition. We measured [Ca2+]i with fluo‐3 in voltage‐clamped rat ventricular myocytes. Increasing SR leak with either caffeine (to sensitise the RyR to Ca activation) or ryanodine (non‐sensitising) had similar effects to SERCA inhibition: decreased systolic [Ca2+]i, increased diastolic [Ca2+]i and slowed decay. However, in the presence of isoproterenol, leak produced a biphasic decay of the Ca transient in the majority of cells while SERCA inhibition produced monophasic decay. Tetracaine reversed the effects of caffeine but not of ryanodine. When caffeine (1 mmol l−1) was added to a cell which displayed Ca waves, the wave frequency initially increased before waves disappeared and biphasic decay developed. Eventually (at higher caffeine concentrations), the
DEFF Research Database (Denmark)
Holmgreen, Lise-Lotte
2014-01-01
The article asks whether it is not the responsibility of corporations to address the issue of women being underrepresented in Danish management jobs. In other words, it is argued that corporations should be encouraged to engage more actively in the recruitment of both men and women for management...... jobs by discursively constructing job ads that appeal to both sexes. This argument is part of the broader field of corporate social responsibility, corporate citizenship, and stakeholder management, which involves discussions of the obligations of corporations to acknowledge and mitigate...... the increasingly widespread impact that their activities have on communities and social structures. The article emphasises the need for more active engagement on the part of corporations by analysing the discursive construction of preferred candidates in a small sample of Danish management job ads. By means...
Ca-Dependent Folding of Human Calumenin
Mazzorana, Marco; Hussain, Rohanah; Sorensen, Thomas
2016-01-01
Human calumenin (hCALU) is a six EF-hand protein belonging to the CREC family. As other members of the family, it is localized in the secretory pathway and regulates the activity of SERCA2a and of the ryanodine receptor in the endoplasmic reticulum (ER). We have studied the effects of Ca2+ binding to the protein and found it to attain a more compact structure upon ion binding. Circular Dichroism (CD) measurements suggest a major rearrangement of the protein secondary structure, which reversibly switches from disordered at low Ca2+ concentrations to predominantly alpha-helical when Ca2+ is added. SAXS experiments confirm the transition from an unfolded to a compact structure, which matches the structural prediction of a trilobal fold. Overall our experiments suggest that calumenin is a Ca2+ sensor, which folds into a compact structure, capable of interacting with its molecular partners, when Ca2+ concentration within the ER reaches the millimolar range. PMID:26991433
ADS National Programmes: France
International Nuclear Information System (INIS)
Studies related to nuclear reactors and radioactive waste started at the French National Centre for Scientific research, CNRS, as a result of the French law on radioactive waste that was published in 1991. They were initially organized around the programme PACE (Physique pour l’Aval du Cycle Electronucléaire = physics of the back end of the nuclear fuel cycle), which became PACEN (Physique pour l’Aval du Cycle et production d’Energie Nucléaire = Physics of the back end of the nuclear fuel cycle and production of nuclear energy) in 2006. Research on accelerator driven systems was from the beginning part of this programme. This research is mainly funded by the National Institute for Nuclear end Particle Physics (IN2P3) of CNRS and within the EURATOM European programmes (FP5, 6 and 7). The programme took place in several stages, and covered various scientific fields, benefitting from expertise of CNRS in the field. More specifically, it aimed and still aims to: – Test and verify the feasibility and design of the ADS concept, in terms of neutronics, physics of materials, design of the accelerator and tests of its prototypical components that have been built (or are at present under construction); – Measure and-or improve nuclear data related to radioactive waste transmutation. Today, most of the activities in support to ADS development carried out by CNRS focus on accelerator developments, GUINEVERE (Generator of Uninterrupted Intense NEutron at the lead VEnus REactor) experiment, ADS core studies, deployment scenarios and nuclear data measurements. The CEA R&D programmes on ADS are mainly focused on the European project EUROTRANS of the 6th Framework programme (2005–2010) and continued in the FREYA project of the 7th Framework Programme
Shelah, Saharon
2011-01-01
We address the following question: Can we expand an NIP theory by adding a linear order such that the expansion is still NIP? Easily, if acl(A)=A for all A, then this is true. Otherwise, we give counterexamples. More precisely, there is a totally categorical theory for which every expansion by a linear order has IP. There is also an \\omega-stable NDOP theory for which every expansion by a linear order interprets bounded arithmetic.
AdS 3-manifolds and Higgs bundles
DEFF Research Database (Denmark)
Alessandrini, Daniele; Li, Qiongling
2015-01-01
In this paper we investigate the relationships between closed AdS 3-manifolds and Higgs bundles. We have a new way to construct AdS structures that allows us to see many of their properties explicitly, for example we can recover the very recent formula by Tholozan for the volumes. We also find...
Evaporation of large black holes in AdS
International Nuclear Information System (INIS)
The AdS/CFT correspondence offers a new perspective on the long-standing black hole information paradox. However, to be able to use the available gauge/gravity machinery one is forced to consider so-called 'large' black holes in AdS, and these objects are thermodynamically stable - they do not evaporate. We describe a simple toy model that allows large AdS black holes to decay, by coupling the emitted radiation to an external scalar field propagating in an auxiliary space. This effectively changes the properties of the boundary of AdS, making it partly absorbing. We demonstrate that the evaporation process never ceases by explicitly presenting (a) the transmission coefficient for a wave scattering from the bulk into auxiliary space and (b) the greybody factor for a black 3-brane in an AdS background. Therefore, the model provides an interesting framework to address the information paradox using AdS/CFT techniques.
Institute of Scientific and Technical Information of China (English)
李小艳
2010-01-01
There is the trend that now people appreciate those who are slim and regard slim even thin people beautiful. The thinner a person is, the more beautiful. Women, born to pursuit beauty, try various means to follow the trend. We all watch TV, and find a lot of advertisements on diet. The effect of them is tremendous. We all know the fact that it is not at all the better mouse trap will catch mouse. The sales methods are more important. If an advertisement is very interesting and seemingly effective, people will be lured by the ad and then try some of the products.
Bao, R; Bao, Ruoyu; Lykken, Joseph
2005-01-01
In the same sense that AdS_5 warped geometries arise naturally from Type IIB string theory with stacks of D3 branes, AdS_7 warped geometries arise naturally from M theory with stacks of M5 branes. We compactify two spatial dimensions of AdS_7 to get AdS_5 x \\Sigma^2, where \\Sigma^2 is e.g. a torus T^2 or a sphere S^2. The metric for \\Sigma inherits the same warp factor as appears in the AdS_5. Bulk fields generically have both Kaluza-Klein and winding modes associated with \\Sigma. In the effective 5d action these will contribute exotic new excitations. We analyze the 5d spectrum in detail for the case of a bulk scalar or a graviton in AdS_5 x T^2, in a setup which mimics the first Randall-Sundrum model. The results display several novel features, some of which might be observed in experiments at the LHC. For example, we obtain TeV scale string winding states without lowering the string scale. This is due to the double warping which is a generic feature of winding states along compactified AdS directions. Expe...
International Nuclear Information System (INIS)
In this article we construct the chirality and Dirac operators on fuzzy AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space. (author)
Dirac Operator on Noncommutative AdS_2
Fakhri, H
2003-01-01
In this article we construct the chirality and Dirac operators on noncommutative AdS_2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated with AdS_2. It is shown that the degeneracy of the spectrum present in the commutative AdS_2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.
Fakhri, Hossein; Imaanpur, Ali
2003-03-01
In this article we construct the chirality and Dirac operators on noncommutative AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.
H. Fakhri; Imaanpur, A.
2003-01-01
In this article we construct the chirality and Dirac operators on noncommutative AdS_2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated with AdS_2. It is shown that the degeneracy of the spectrum present in the commutative AdS_2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.
Radius-dependent gauge unification in AdS5
Choi, Kiwoon; Kim, Hyung Do; Kim, Ian-Woo
2002-01-01
We examine the relation of the 4-dimensional low energy coupling of bulk gauge boson in a slice of AdS5 to the 5-dimensional fundamental couplings as a function of the orbifold radius R. This allows us to address the gauge coupling unification in AdS5 by means of the radius running as well as the conventional momentum running. We then compute the radius dependence of 1-loop low energy couplings in generic AdS5 theory with 4-dimensional supersymmetry, and discuss the low energy predictions whe...
Towards integrability for AdS3/CFT2
Sfondrini, Alessandro
2014-01-01
We review the recent progress towards applying worldsheet integrability techniques to the $AdS_3/CFT_2$ correspondence to find its all-loop S matrix and Bethe-Yang equations. We study in full detail the massive sector of $AdS_3\\times S^3\\times T^4$ superstrings supported by pure Ramond-Ramond (RR) fluxes. The extension of this machinery to accommodate massless modes, to the $AdS_3\\times S^3\\times S^3\\times S^1$ pure-RR background and to backgrounds supported by mixed background fluxes is also reviewed. While the results discussed here were found elsewhere, our exposition is original.
Computer Simulation for Effect of Tb3+ on Ca2+Speciation in Human Plasma
Institute of Scientific and Technical Information of China (English)
卢兴; 王悦; 张海元; 王进平; 牛春吉; 倪嘉缵
2002-01-01
Effect of Tb3+ on Ca2+ speciation in human plasma was studied by means of the computer program of MINTEQA2. When Tb3+ ions are not added into the system, Ca2+ ions mostly distribute in free Ca2+ (74.7%) and the surplus distributes in Ca2+ complexes, such as [CaHCO3]+(7.9%), [Ca(Lac)]+(6.4%), CaHPO4 (1.3%), [CaHistidinateThreoninateH3]3+(2.4%), [CaCitrateHistidinateH2] (2.3%) and CaCO3(1.1%). Tb3+ can compete with Ca2+ for inorganic as well as biological ligands. An increase of concentration of Tb3+ in the system results in an increase of content of free Ca2+ and a decrease of contents of Ca2+ complexes.
Conical singularities in AdS space time
International Nuclear Information System (INIS)
Full text: In recent years, the study of conformal gauge theories from 10-D has been motivated by the AdSd+1/CFTd correspondence, first conjectured by J. Maldacena. The aim of this work is to consider the d = 4 case by analysing the configuration of the N coincident D3 branes. In this context, the work shows that there is a duality between type IIB string theory in AdS5 x S5 and N = 4 SU(N) Super Yang-Mills Theory in the IR. The AdS5/CFT4 correspondence brought also new approaches to the strong coupling problem in QCD. Nowadays, there is a whole line of works that focus on the low dimensional correspondence AdS4/CFT3, like the application to graphene and topological insulators, and the AdS3/CFT2 correspondence, related with the entanglement entropy. In this work, we consider the vortex configuration solution to the AdS4 and AdS3 space-time. The most important motivation is to discuss the boundary theory resulting from these solutions. We have examined a straightforward approach to a holographic computation of the graphene and entanglement entropy in the presence of the conical singularity. After this analysis, we consider the scalar field in the bulk in the presence of this metrics and work out the compactification modes. Taking the holographic point of view, we study and discuss the resulting Green function. (author)
Directory of Open Access Journals (Sweden)
Hong-Chuan Yang
2007-01-01
Full Text Available We study the energy-efficient configuration of multihop paths with automatic repeat request (ARQ mechanism in wireless ad hoc networks. We adopt a cross-layer design approach and take both the quality of each radio hop and the battery capacity of each transmitting node into consideration. Under certain constraints on the maximum tolerable transmission delay and the required packet delivery ratio, we solve optimization problems to jointly schedule the transmitting power of each transmitting node and the retransmission limit over each hop. Numerical results demonstrate that the path configuration methods can either significantly reduce the average energy consumption per packet delivery or considerably extend the average lifetime of the multihop route.
ADS National Programmes: Netherlands
International Nuclear Information System (INIS)
The ADS related activities within the Netherlands are concentrated at NRG. From 2000 to 2006, NRG supported SCK•CEN in their development of MYRRHA. The support was mainly devoted to Computational Fluid Dynamics (CFD) simulations for the windowless target option. This collaboration was prolonged within the framework of the EU FP6 EUROTRANS project. Eventually this lead to a solution strategy for the hydraulic (without heat transfer) evaluation of a windowless target with one free surface using an Eulerian-Eulerian modeling approach. As a second free surface was added to the target design later, this approach would need to be revisited. The developed approach was applied to an assess the feasibility of a three feeder windowless target design. This preliminary assessment confirmed that there were no serious show stoppers for a three feeder design. Another study undertaken using related to the windowless target was a preliminary assessment of the risk of lead-bismuth splashing in case of a sudden heat deposition by the beam, e.g. at beam startup or beam interuptions. Within the framework of the EU FP7 CDT project, a window target is currently being assessed thermalhydraulicly in collaboration with SCK•CEN. Within the EU FP5 ASCHLIM project, the state of the art with regard to turbulence modelling for CFD approaches was determined. It was concluded that accurate simulation of heat transport in HLM was not feasible, especially in natural or mixed convection regimes. Within the EU FP7 THINS project this issue is currently being treated. NRG assists the commercial CFD code vendor CD adapco in implementing and testing a promising, academically tested, algebraic heat flux model
Borsato, Riccardo; Sfondrini, Alessandro; Stefanski, Bogdan; Torrielli, Alessandro
2013-01-01
We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3 x S3 x T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly-coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their sub-leading order and compare it with recent one-loop perturbative results, and co
Borsato, Riccardo; Ohlsson Sax, Olof; Sfondrini, Alessandro; Stefański, Bogdan, Jr.; Torrielli, Alessandro
2013-09-01
We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3×S3×T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their subleading order and compare it with recent one-loop perturbative results and comment on their weak-coupling expansion.
Chaos and hydrodynamics near AdS$_2$
Jensen, Kristan
2016-01-01
We revisit AdS$_2$ holography with the Sachdev-Ye-Kitaev models in mind. Our main result is to rewrite a generic theory of gravity near an AdS$_2$ throat as a novel hydrodynamics coupled to the correlation functions of a conformal quantum mechanics. This gives a prescription for the computation of $n$-point functions in the dual quantum mechanics. We thereby find that the dual is maximally chaotic.
Discrimination in Online Ad Delivery
Sweeney, Latanya
2013-01-01
A Google search for a person's name, such as "Trevon Jones", may yield a personalized ad for public records about Trevon that may be neutral, such as "Looking for Trevon Jones?", or may be suggestive of an arrest record, such as "Trevon Jones, Arrested?". This writing investigates the delivery of these kinds of ads by Google AdSense using a sample of racially associated names and finds statistically significant discrimination in ad delivery based on searches of 2184 racially associated person...
ADS National Programmes: Germany
International Nuclear Information System (INIS)
The German R&D programme for ADS development is related to the partitioning and transmutation of spent fuel. This programme is implemented mainly by the three national research centres belonging to the Helmholtz Association, i.e. Karlsruhe Institute of Technology (KIT), Forschungszentrum Jülich (FZJ) in cooperation with the Technical University of Aachen (RWTH Aachen) and the Helmholtz Zentrum Dresden Rossendorf (HZDR). The main purpose of this R&D programme is the prospect to manage the high level radioactive waste such as to reduce the burden on a final repository. P&T does not eliminate the need for a final repository whatever the strategy, but it allows the reduction of the radio-toxicity associated with radioactive waste, the increase of the repository capacity as a consequence of the reduction of masses to be stored and their associated residual heat load. Different fuel cycle scenarios to implement P&T can be envisaged. These scenarios have been evaluated to identify the impact of P&T on the characteristics, number and deployment pace of the installations of the fuel cycle (reprocessing, fuel fabrication, storage etc). Almost all activities conducted in the R&D programme are embedded in European and international projects and initiatives. In the following more details on the relevant components of the R&D programme are summarized
Constructing the AdS dual of a Fermi liquid: AdS Black holes with Dirac hair
\\vCubrović, Mihailo; Schalm, Koenraad
2010-01-01
We provide new evidence that the holographic dual to a strongly coupled charged Fermi Liquid has a non-zero fermion density in the bulk. We show that the pole-strength of the stable quasiparticle characterizing the Fermi surface is encoded in the spatially averaged AdS probability density of a single normalizable fermion wavefunction in AdS. Recalling Migdal's theorem which relates the pole strength to the Fermi-Dirac characteristic discontinuity in the number density at $\\ome_F$, we conclude that the AdS dual of a Fermi liquid is described by occupied on-shell fermionic modes in AdS. Encoding the occupied levels in the total probability density of the fermion field directly, we show that an AdS Reissner-Nordstr\\"{o}m black hole in a theory with charged fermions has a critical temperature, at which the system undergoes a first-order transition to a black hole with a non-vanishing profile for the bulk fermion field. Thermodynamics and spectral analysis confirm that the solution with non-zero AdS fermion-profil...
Different views of AEGIS / AD-6 Experiment (AD facility) AD-6
Maximilien Brice
2012-01-01
Different views of AEGIS / AD-6 Experiment (AD facility) in July of 2012. The visible parts are the positron accumulator (blue structures on top of of the antiproton extraction line) and the 5T magnet which traps the antiprotons.
Global geometric properties of AdS space and the AdS/CFT correspondence
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The Poisson kernels and relations between them for a massive scalar field in a unit ball Bn with Hua's metric and conformal flat metric are obtained by describing the Bn as a submanifold of an (n+1)-dimensional embedding space. Global geometric properties of the AdS space are discussed. We show that the(n+1)-dimensional AdS space AdSn+1 is isomorphic to RP1×Bn and boundary of the AdS is isomorphic to RP1×Sn-1. Bulk-boundary propagator and the AdS/CFT like correspondence are demonstrated based on these global geometric properties of the RP1×Bn.
Clark, T E
2016-01-01
Coset methods are used to determine the action of a co-dimension one brane (domain wall) embedded in (d+1)-dimensional AdS space in the Carroll limit in which the speed of light goes to zero. The action is invariant under the non-linearly realized symmetries of the AdS-Carroll spacetime. The Nambu-Goldstone field exhibits a static spatial distribution for the brane with a time varying momentum density related to the brane's spatial shape as well as the AdS-C geometry. The AdS-C vector field dual theory is obtained.
Entanglement entropy for free scalar fields in AdS
Sugishita, Sotaro
2016-01-01
We compute entanglement entropy for free massive scalar fields in anti-de Sitter (AdS) space. The entangling surface is a minimal surface whose boundary is a sphere at the boundary of AdS. The entropy can be evaluated from the thermal free energy of the fields on a topological black hole by using the replica method. In odd-dimensional AdS, exact expressions of the Renyi entropy S_n are obtained for arbitrary n. We also evaluate 1-loop corrections coming from the scalar fields to holographic entanglement entropy. Applying the results, we compute the leading difference of entanglement entropy between two holographic CFTs related by a renormalization group flow triggered by a double trace deformation. The difference is proportional to the shift of a central charge under the flow.
Detailed ultraviolet asymptotics for AdS scalar field perturbations
Evnin, Oleg
2016-01-01
We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.
Asymptotically AdS spacetimes with a timelike Kasner singularity
Ren, Jie
2016-07-01
Exact solutions to Einstein's equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution's appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.
Microstates at the boundary of AdS
Mathur, Samir D
2011-01-01
The bound states of the D1D5 brane system have a known gravitational description: flat asymptotics, an anti-de Sitter region, and a 'cap' ending the AdS region. We construct perturbations that correspond to the action of chiral algebra generators on Ramond ground states of D1D5 branes. Abstract arguments in the literature suggest that the perturbation should be pure gauge in the AdS region; our perturbation indeed has this structure, with the nontrivial deformation of the geometry occurring at the 'neck' between the AdS region and asymptotic infinity. This 'non-gauge' deformation is needed to provide the nonzero energy and momentum carried by the perturbation. We also suggest implications this structure may have for the majority of microstates which live at the cap.
Null warped AdS in higher spin gravity
Breunhoelder, Veronika; Grumiller, Daniel; Prohazka, Stefan
2015-01-01
We equip three-dimensional spin-3 gravity in the principal embedding with a new set of boundary conditions that we call "asymptotically null warped AdS". We find a chiral copy of the Polyakov-Bershadsky algebra as asymptotic symmetry algebra, reminiscent of the situation in topologically massive gravity with strict null warped AdS boundary conditions. We prove the invertibility of the map between zuvielbein and metric variables and construct a global gauge transformation to half of AdS spin-3 gravity in the diagonal embedding. This explains why the theory is chiral and why the Polyakov-Bershadsky algebra arises. We then introduce chemical potentials, derive the entropy, free energy, and the holographic response functions, and conclude with a discussion.
New massive gravity and AdS(4) counterterms.
Jatkar, Dileep P; Sinha, Aninda
2011-04-29
We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory. PMID:21635026
Towards integrability for AdS3/CFT2
International Nuclear Information System (INIS)
We review the recent progress towards applying worldsheet integrability techniques to the AdS3/CFT2 correspondence to find its all-loop S matrix and Bethe–Yang equations. We study in full detail the massive sector of AdS3×S3×T4 superstrings supported by pure Ramond–Ramond (RR) fluxes. The extension of this machinery to accommodate massless modes, to the AdS3×S3×S3×S1 pure-RR background and to backgrounds supported by mixed background fluxes is also reviewed. While the results discussed here were found elsewhere, our presentation sometimes deviates from the one found in the original literature in an effort to be pedagogical and self-contained. (topical review)
Logarithmic conformal field theories and AdS correspondence
Khorrami, A. M. Ghezelbash. M.; Aghamohammadi, A
1998-01-01
We generalize the Maldacena correspondence to the logarithmic conformal field theories. We study the correspondence between field theories in (d+1)-dimensional AdS space and the d-dimensional logarithmic conformal field theories in the boundary of $AdS_{d+1}$. Using this correspondence, we get the n-point functions of the corresponding logarithmic conformal field theory in d-dimensions.
Phases of Global AdS Black Holes
Basu, Pallab; Subramanian, P N Bala
2016-01-01
We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ($AdS_4$) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.
Phases of global AdS black holes
Basu, Pallab; Krishnan, Chethan; Subramanian, P. N. Bala
2016-06-01
We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ( AdS 4) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.
Mixed-symmetry fields in AdS(5), conformal fields, and AdS/CFT
Metsaev, R R
2014-01-01
Mixed-symmetry arbitrary spin massive, massless, and self-dual massive fields in AdS(5) are studied. Light-cone gauge actions for such fields leading to decoupled equations of motion are constructed. Light-cone gauge formulation of mixed-symmetry anomalous conformal currents and shadows in 4d flat space is also developed. AdS/CFT correspondence for normalizable and non-normalizable modes of mixed-symmetry AdS fields and the respective boundary mixed-symmetry anomalous conformal currents and shadows is studied. We demonstrate that the light-cone gauge action for massive mixed-symmetry AdS field evaluated on solution of the Dirichlet problem amounts to the light-cone gauge 2-point vertex of mixed-symmetry anomalous shadow. Also we show that UV divergence of the action for mixed-symmetry massive AdS field with some particular value of mass parameter evaluated on the Dirichlet problem amounts to the action of long mixed-symmetry conformal field, while UV divergence of the action for mixed-symmetry massless AdS fi...
Compact AdS space, Brane geometry and the AdS/CFT correspondence
Boschi-Filho, H; Boschi-Filho, Henrique; Braga, Nelson R. F.
2002-01-01
The AdS/CFT correspondence can be realized in spaces that are globally different but share the same asymptotic behavior. Two known cases are: a compact AdS space and the space generated by a large number of coincident branes. We discuss the physical consistency, in the sense of the Cauchy problem, of these two formulations. We show that the role of the boundary in the compact AdS space is equivalent to that of the flat asymptotic region in the brane space. We also show, by introducing a second coordinate chart for the pure AdS space, that a point at its spatial infinity corresponds to a horizon in the brane system.
BRST Quantization of String Theory in AdS(3)
Pakman, A
2003-01-01
We study the BRST quantization of bosonic and NSR strings propagating in AdS(3) x N backgrounds. The no-ghost theorem is proved using the Frenkel-Garland-Zuckerman method. Regular and spectrally-flowed representations of affine SL(2,R) appear on an equal footing. Possible generalizations to related curved backgrounds are discussed.
Logarithmic AdS waves and Zwei-Dreibein gravity
Bergshoeff, Eric A.; Goya, Andres F.; Merbis, Wout; Rosseel, Jan
2014-01-01
We show that the parameter space of Zwei-Dreibein Gravity (ZDG) in AdS(3) exhibits critical points, where massive graviton modes coincide with pure gauge modes and new 'logarithmic' modes appear, similar to what happens in New Massive Gravity. The existence of critical points is shown both at the li
Internet Advertising. Google AdWords versus Facebook Ads
Directory of Open Access Journals (Sweden)
Paul PAŞCU
2014-05-01
Full Text Available This article describes how to use the applications for Internet advertising, Google AdWords and Facebook Ads. Our attempt is to present the advantages and disadvantages of each of them, the costs and benefits, a useful aspect for companies that plan to start advertising campaigns on the Internet.
Penrose inequality for asymptotically AdS spaces
Energy Technology Data Exchange (ETDEWEB)
Itkin, Igor [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Oz, Yaron, E-mail: yaronoz@post.tau.ac.il [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel)
2012-02-28
In general relativity, the Penrose inequality relates the mass and the entropy associated with a gravitational background. If the inequality is violated by an initial Cauchy data, it suggests a creation of a naked singularity, thus providing means to consider the cosmic censorship hypothesis. We propose a general form of Penrose inequality for asymptotically locally AdS spaces.
Internet Advertising. Google AdWords versus Facebook Ads
Paul PAŞCU
2014-01-01
This article describes how to use the applications for Internet advertising, Google AdWords and Facebook Ads. Our attempt is to present the advantages and disadvantages of each of them, the costs and benefits, a useful aspect for companies that plan to start advertising campaigns on the Internet.
Directory of Open Access Journals (Sweden)
Yawu Liu
Full Text Available To compare the accuracies of predicting AD conversion by using a decision support system (PredictAD tool and current research criteria of prodromal AD as identified by combinations of episodic memory impairment of hippocampal type and visual assessment of medial temporal lobe atrophy (MTA on MRI and CSF biomarkers.Altogether 391 MCI cases (158 AD converters were selected from the ADNI cohort. All the cases had baseline cognitive tests, MRI and/or CSF levels of Aβ1-42 and Tau. Using baseline data, the status of MCI patients (AD or MCI three years later was predicted using current diagnostic research guidelines and the PredictAD software tool designed for supporting clinical diagnostics. The data used were 1 clinical criteria for episodic memory loss of the hippocampal type, 2 visual MTA, 3 positive CSF markers, 4 their combinations, and 5 when the PredictAD tool was applied, automatically computed MRI measures were used instead of the visual MTA results. The accuracies of diagnosis were evaluated with the diagnosis made 3 years later.The PredictAD tool achieved the overall accuracy of 72% (sensitivity 73%, specificity 71% in predicting the AD diagnosis. The corresponding number for a clinician's prediction with the assistance of the PredictAD tool was 71% (sensitivity 75%, specificity 68%. Diagnosis with the PredictAD tool was significantly better than diagnosis by biomarkers alone or the combinations of clinical diagnosis of hippocampal pattern for the memory loss and biomarkers (p≤0.037.With the assistance of PredictAD tool, the clinician can predict AD conversion more accurately than the current diagnostic criteria.
Coset construction of AdS particle dynamics
Heinze, Martin; Megrelidze, Luka
2016-01-01
We analyze dynamics of the AdS$_{N+1}$ particle realized on the coset SO$(2,N)/$SO$(1,N)$. Hamiltonian reduction provides the physical phase space in terms of the coadjoint orbit obtained by boosting a timelike element of ${\\frak so}(2,N)$. We show equivalence of this approach to geometric quantization and to the SO$(N)$ covariant oscillator description, for which the boost generators entail a complicated operator ordering. As an alternative scheme, we introduce dual oscillator variables and derive their algebra at the classical and the quantum level. This simplifies the calculations of the commutators for the boost generators and leads to unitary irreducible representations of ${\\frak so}(2,N)$ for all admissible values of the mass parameter. We furthermore discuss a SO$(N)$ covariant supersymmetric extensions of the oscillator quantization, with its realization for superparticles in AdS$_2$ and AdS$_3$ given by recent works.
Entanglement temperature and perturbed AdS3 geometry
Levine, G. C.; Caravan, B.
2016-06-01
Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .
AdS5 backgrounds with 24 supersymmetries
Beck, S.; Gutowski, J.; Papadopoulos, G.
2016-06-01
We prove a non-existence theorem for smooth AdS 5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D = 11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS 5 × S 5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if gravitational duals for strictly mathcal{N}=3 superconformal theories in 4-dimensions exist, they are either singular or their internal spaces are not compact.
AdS5 Backgrounds with 24 Supersymmetries
Beck, S W; Papadopoulos, G
2016-01-01
We prove a non-existence theorem for smooth AdS5 solutions with connected, compact without boundary internal space that preserve strictly 24 supersymmetries. In particular, we show that D=11 supergravity does not admit such solutions, and that all such solutions of IIB supergravity are locally isometric to the AdS_5 * S^5 maximally supersymmetric background. Furthermore, we prove that (massive) IIA supergravity also does not admit such solutions, provided that the homogeneity conjecture for massive IIA supergravity is valid. In the context of AdS/CFT these results imply that if strictly N=3 superconformal theories in 4-dimensions exist, their gravitational dual backgrounds are either singular or their internal spaces are not compact.
Self-dual warped AdS3 black holes
Chen, Bin; Ning, Bo
2010-12-01
We study a new class of solutions of three-dimensional topological massive gravity. These solutions can be taken as nonextremal black holes, with their extremal counterparts being discrete quotients of spacelike warped AdS3 along the U(1)L isometry. We study the thermodynamics of these black holes and show that the first law is satisfied. We also show that for consistent boundary conditions, the asymptotic symmetry generators form only one copy of the Virasoro algebra with central charge cL=(4νℓ)/(G(ν2+3)), with which the Cardy formula reproduces the black hole entropy. We compute the real-time correlators of scalar perturbations and find a perfect match with the dual conformal field theory (CFT) predictions. Our study provides a novel example of warped AdS/CFT correspondence: the self-dual warped AdS3 black hole is dual to a CFT with nonvanishing left central charge. Moreover, our investigation suggests that the quantum topological massive gravity asymptotic to the same spacelike warped AdS3 in different consistent ways may be dual to different two-dimensional CFTs.
Ultraviolet asymptotics for quasiperiodic AdS_4 perturbations
Craps, Ben; Jai-akson, Puttarak; Vanhoof, Joris
2015-01-01
Spherically symmetric perturbations in AdS-scalar field systems of small amplitude epsilon approximately periodic on time scales of order 1/epsilon^2 (in the sense that no significant transfer of energy between the AdS normal modes occurs) have played an important role in considerations of AdS stability. They are seen as anchors of stability islands where collapse of small perturbations to black holes does not occur. (This collapse, if it happens, typically develops on time scales of the order 1/epsilon^2.) We construct an analytic treatment of the frequency spectra of such quasiperiodic perturbations, paying special attention to the large frequency asymptotics. For the case of a self-interacting phi^4 scalar field in a non-dynamical AdS background, we arrive at a fairly complete analytic picture involving quasiperiodic spectra with an exponential suppression modulated by a power law at large mode numbers. For the case of dynamical gravity, the structure of the large frequency asymptotics is more complicated....
Kolmogorov-Zakharov spectrum in AdS gravitational collapse.
de Oliveira, H P; Pando Zayas, Leopoldo A; Rodrigues, E L
2013-08-01
We study black hole formation during the gravitational collapse of a massless scalar field in asymptotically D-dimensional anti-de Sitter AdS(D) spacetimes for D = 4, 5. We conclude that spherically symmetric gravitational collapse in asymptotically AdS spaces is turbulent and characterized by a Kolmogorov-Zakharov spectrum. Namely, we find that after an initial period of weakly nonlinear evolution, there is a regime where the power spectrum of the Ricci scalar evolves as ω(-s) with the frequency, ω, and s ≈ 1.7 ± 0.1.
Technology of Ad hoc Networks%Ad hoc技术
Institute of Scientific and Technical Information of China (English)
曹常义
2002-01-01
Ad hoc技术是从无线移动Ad hoc网络(WMANET)抽象出来的一个一般性概念,该项技术所标称的是自组识、多跳的一个临时分布式系统,是一种网络构架技术.它要面临多项难题.本文就是从OSI模型的角度把Ad hoc技术分层介绍,最后给出了一种WMANET应用方案.
The Ca(2+)/Calmodulin/CaMKK2 Axis: Nature's Metabolic CaMshaft.
Marcelo, Kathrina L; Means, Anthony R; York, Brian
2016-10-01
Calcium (Ca(2+)) is an essential ligand that binds its primary intracellular receptor calmodulin (CaM) to trigger a variety of downstream processes and pathways. Central to the actions of Ca(2+)/CaM is the activation of a highly conserved Ca(2+)/CaM kinase (CaMK) cascade that amplifies Ca(2+) signals through a series of subsequent phosphorylation events. Proper regulation of Ca(2+) flux is necessary for whole-body metabolism and disruption of Ca(2+) homeostasis has been linked to various metabolic diseases. Here we provide a synthesis of recent advances that highlight the roles of the Ca(2+)/CaMK axis in key metabolic tissues. An appreciation of this information is critical to understanding the mechanisms by which Ca(2+)/CaM-dependent signaling contributes to metabolic homeostasis and disease.
Universal isolation in the AdS landscape
Danielsson, U H; Vargas, S C
2016-01-01
We study the universal conditions for quantum non-perturbative stability against bubble nucleation for pertubatively stable AdS vacua based on positive energy theorems. We also compare our analysis with the pre-existing ones in the literature carried out within the thin-wall approximation. The aforementioned criterion is then tested in two explicit examples describing massive type IIA string theory compactified on $S^3$ and $S^3\\,\\times\\,S^3$, respectively. The AdS landscape of both classes of compactifications is known to consist of a set of isolated points. The main result is that all critical points respecting the Breitenlohner-Freedaman (BF) bound also turn out be stable at a non-perturbative level. Finally, we speculate on the possible universal features that may be extracted from the above specific examples.
Thermodynamics of Einstein-Proca AdS Black Holes
Liu, Hai-Shan; Pope, C N
2014-01-01
We study static spherically-symmetric solutions of the Einstein-Proca equations in the presence of a negative cosmological constant. We show that the theory admits solutions describing both black holes and also solitons in an asymptotically AdS background. Interesting subtleties can arise in the computation of the mass of the solutions and also in the derivation of the first law of thermodynamics. We make use of holographic renormalisation in order to calculate the mass, even in cases where the solutions have a rather slow approach to the asymptotic AdS geometry. By using the procedure developed by Wald, we derive the first law of thermodynamics for the black hole and soliton solutions. This includes a non-trivial contribution associated with the Proca "charge." The solutions cannot be found analytically, and so we make use of numerical integration techniques to demonstrate their existence.
AdS nonlinear instability: moving beyond spherical symmetry
Dias, Oscar J C
2016-01-01
Anti-de Sitter (AdS) is conjectured to be nonlinear unstable to a weakly turbulent mechanism that develops a cascade towards high frequencies, leading to black hole formation [1,2]. We give evidence that the gravitational sector of perturbations behaves differently from the scalar one studied in [2]. In contrast with [2], we find that not all gravitational normal modes of AdS can be nonlinearly extended into periodic horizonless smooth solutions of the Einstein equation. In particular, we show that even seeds with a single normal mode can develop secular resonances, unlike the spherically symmetric scalar field collapse studied in [2]. Moreover, if the seed has two normal modes, more than one resonance can be generated at third order, unlike the spherical collapse of [2]. We also show that weak turbulent perturbative theory predicts the existence of direct and inverse cascades, with the former dominating the latter for equal energy two-mode seeds.
Perturbative entanglement thermodynamics for AdS spacetime: Renormalization
Mishra, Rohit
2015-01-01
We study the effect of charged excitations in the AdS spacetime on the first law of entanglement thermodynamics. It is found that `boosted' AdS black holes give rise to a more general form of first law which includes chemical potential and charge density. To obtain this result we have to resort to a second order perturbative calculation of entanglement entropy for small size subsystems. At first order the form of entanglement law remains unchanged even in the presence of charged excitations. But the thermodynamic quantities have to be appropriately `renormalized' at the second order due to the corrections. We work in the perturbative regime where $T_{thermal}\\ll T_E$.
Smoothed Transitions in Higher Spin AdS Gravity
Banerjee, Shamik; Hellerman, Simeon; Hijano, Eliot; Lepage-Jutier, Arnaud; Maloney, Alexander; Shenker, Stephen
2012-01-01
We consider CFTs conjectured to be dual to higher spin theories of gravity in AdS_3 and AdS_4. Two dimensional CFTs with W_N symmetry are considered in the lambda=0 (k --> infinity) limit, where they are conjectured to be described by continuous orbifolds. The torus partition function is computed, using reasonable assumptions, and equals that of a free field theory. We find no phase transition at temperatures of order one; the usual Hawking-Page phase transition is removed by the highly degenerate light states associated with conical defect states in the bulk. Three dimensional Chern-Simons-matter CFTs with vector-like matter are considered on T^3, where the dynamics is described by an effective theory for the eigenvalues of the holonomies. Likewise, we find no evidence for a Hawking-Page phase transition at large level k.
Ambitwistors, oscillators and massless fields on $AdS_5$
Uvarov, D V
2016-01-01
Positive energy unitary irreducible representations of $SU(2,2)$ can be constructed with the aid of bosonic oscillators in (anti)fundamental representation of $SU(2)_L\\times SU(2)_R$ that are closely related to Penrose twistors. Starting with the correspondence between the doubleton representations, homogeneous functions on projective twistor space and on-shell $SL(2,\\mathbb C)$ generalized Weyl curvature spinors and their low-spin counterparts, we study in the similar way the correspondence between the massless representations, homogeneous functions on ambitwistor space and, via the Penrose transform, with the gauge fields on Minkowski boundary of $AdS_5$. The possibilities of reconstructing massless fields on $AdS_5$ and some applications are also discussed.
The Mixed Phase of Charged AdS Black Holes
Directory of Open Access Journals (Sweden)
Piyabut Burikham
2016-01-01
Full Text Available We study the mixed phase of charged AdS black hole and radiation when the total energy is fixed below the threshold to produce a stable charged black hole branch. The coexistence conditions for the charged AdS black hole and radiation are derived for the generic case when radiation particles carry charge. The phase diagram of the mixed phase is demonstrated for both fixed potential and charge ensemble. In the dual gauge picture, they correspond to the mixed phase of quark-gluon plasma (QGP and hadron gas in the fixed chemical potential and density ensemble, respectively. In the nuclei and heavy-ion collisions at intermediate energies, the mixed phase of exotic QGP and hadron gas could be produced. The mixed phase will condense and evaporate into the hadron gas as the fireball expands.
Semiclassical Virasoro Blocks from AdS$_3$ Gravity
Hijano, Eliot; Perlmutter, Eric; Snively, River
2015-01-01
We present a unified framework for the holographic computation of Virasoro conformal blocks at large central charge. In particular, we provide bulk constructions that correctly reproduce all semiclassical Virasoro blocks that are known explicitly from conformal field theory computations. The results revolve around the use of geodesic Witten diagrams, recently introduced in arXiv:1508.00501, evaluated in locally AdS$_3$ geometries generated by backreaction of heavy operators. We also provide an alternative computation of the heavy-light semiclassical block -- in which two external operators become parametrically heavy -- as a certain scattering process involving higher spin gauge fields in AdS$_3$; this approach highlights the chiral nature of Virasoro blocks. These techniques may be systematically extended to compute corrections to these blocks and to interpolate amongst the different semiclassical regimes.
Semiclassical Virasoro blocks from AdS3 gravity
Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River
2015-12-01
We present a unified framework for the holographic computation of Virasoro conformal blocks at large central charge. In particular, we provide bulk constructions that correctly reproduce all semiclassical Virasoro blocks that are known explicitly from conformal field theory computations. The results revolve around the use of geodesic Witten diagrams, recently introduced in [1], evaluated in locally AdS3 geometries generated by backreaction of heavy operators. We also provide an alternative computation of the heavy-light semiclassical block — in which two external operators become parametrically heavy — as a certain scattering process involving higher spin gauge fields in AdS3; this approach highlights the chiral nature of Virasoro blocks. These techniques may be systematically extended to compute corrections to these blocks and to interpolate amongst the different semiclassical regimes.
Alday-Maldacena duality and AdS Plateau problem
Morozov, A.
2008-01-01
A short summary of approximate approach to the study of minimal surfaces in AdS, based on solving Nambu-Goto equations iteratively. Today, after partial denunciation of the BDS conjecture, this looks like the only constructive approach to understanding the ways of its possible modification and thus to saving the Alday-Maldacena duality. Numerous open technical problems are explicitly formulated throughout the text.
One loop gauge couplings in AdS5
Choi, Kiwoon; Kim, Ian-Woo
2002-01-01
We calculate the full 1-loop corrections to the low energy coupling of bulk gauge boson in a slice of AdS5 which are induced by generic 5-dimensional scalar, Dirac fermion, and vector fields with arbitrary Z_2 times Z_2' orbifold boundary conditions. In supersymmetric limit, our results correctly reproduce the results obtained by an independent method based on 4-dimensional effective supergravity. This provides a nontrivial check of our results and assures the regularization scheme-independen...
Universal Kounterterms in Lovelock AdS gravity
Kofinas, Georgios; Olea, Rodrigo
2008-01-01
We show the universal form of the boundary term (Kounterterm series) which regularizes the Euclidean action and background-independent definition of conserved quantities for any Lovelock gravity theory with AdS asymptotics (including Einstein-Hilbert and Einstein-Gauss-Bonnet). We discuss on the connection of this procedure to the existence of topological invariants and Chern-Simons forms in the corresponding dimensions.
Mellin amplitudes for $AdS_5\\times S^5$
Rastelli, Leonardo
2016-01-01
We revisit the calculation of holographic correlation functions in IIB supergravity on $AdS_5\\times S^5$. Results for four-point functions simplify drastically when expressed in Mellin space. We conjecture a compact formula for the four-point functions of one-half BPS singe-trace operators of arbitrary weight. Our methods rely on general consistency conditions and eschew detailed knowledge of the supergravity effective action.
N=2 supersymmetric sigma-models in AdS
Butter, Daniel
2011-01-01
We construct the most general N=2 supersymmetric nonlinear sigma-model in four-dimensional anti-de Sitter (AdS) space in terms of N=1 chiral superfields. The target space is shown to be a non-compact hyperkahler manifold restricted to possess a special Killing vector field. A remarkable property of the sigma-model constructed is that the algebra of OSp(2|4) transformations is closed off the mass shell.
AdS sub 3 gravity and conformal field theories
Behrndt, K; Gaida, I
1999-01-01
We present a detailed analysis of AdS sub 3 gravity, the BTZ black hole and the associated conformal field theories (CFTs). In particular we focus on the non-extreme six-dimensional string solution with background metric AdS sub 3 x S sup 3 near the horizon. In addition we introduce momentum modes along the string, corresponding to a BTZ black hole, and a Taub-NUT soliton in the transverse Euclidean space. We show that the AdS sub 3 space-time of this configuration has the spatial geometry of an annulus with a Liouville model at the outer boundary and a two-dimensional black hole at the inner boundary. These CFTs provide the dynamical degrees of freedom of the three-dimensional effective model and, together with the CFT corresponding to S sup 3 , provide a statistical interpretation of the corresponding Bekenstein-Hawking entropy. We test the proposed exact black hole entropy, which should hold to all orders in alpha', by an independent field theoretical analysis including higher-order curvature corrections. ...
SUSY properties of warped AdS$_3$
Jeong, Jaehoon; Yoshida, Kentaroh
2014-01-01
We examine supersymmetric properties of null-warped AdS$_3$, or alternatively Schrodinger geometries, dual to putative warped CFTs in two dimensions. We classify super Schrodinger subalgebras of the superalgebra psu(1, 1$|$2) $\\oplus$ psu(1, 1$|$2) , corresponding to the superconformal algebra of the AdS$_3 \\times$ S$^3$ geometry. We comment on geometric realisations and provide a string theory description with enhanced supersymmetry in terms of intersecting D3-branes. For type IIB supergravity solutions based on T$^{1,1}$, we consider the relationship between five-dimensional Schrodinger solutions and their three-dimensional null-warped counterparts, corresponding to R symmetry twists. Finally, we study a family of null-warped AdS$_3$ solutions in a setting where there is an ambiguity over the R symmetry and confirm that, for examples admitting a KK reduction to three dimensions, the minimisation of a real superpotential of the three-dimensional gauged supergravity captures the central charge and R symmetry.
AdS Field Theory from Conformal Field Theory
Fitzpatrick, A Liam
2012-01-01
We provide necessary and sufficient conditions for a Conformal Field Theory to have a description in terms of a perturbative Effective Field Theory in AdS. The first two conditions are well-known: the existence of a perturbative `1/N' expansion and an approximate Fock space of states generated by a finite number of low-dimension operators. We add a third condition, that the Mellin amplitudes of the CFT correlators must be well-approximated by functions that are bounded by a polynomial at infinity in Mellin space, or in other words, that the Mellin amplitudes have an effective theory-type expansion. We explain the relationship between our conditions and unitarity, and provide an analogy with scattering amplitudes that becomes exact in the flat space limit of AdS. The analysis also yields a simple connection between conformal blocks and AdS diagrams, providing a new calculational tool very much in the spirit of the S-Matrix program. We also begin to explore the potential pathologies associated with higher spin ...
N=2 AdS supergravity and supercurrents
Butter, Daniel
2011-01-01
We consider the minimal off-shell formulation for four-dimensional N=2 supergravity with a cosmological term, in which the second compensator is an improved tensor multiplet. We use it to derive a linearized supergravity action (and its dual versions) around the anti-de Sitter (AdS) background in terms of three N=2 off-shell multiplets: an unconstrained scalar superfield, vector and tensor multiplets. This allows us to deduce the structure of the supercurrent multiplet associated with those supersymmetric theories which naturally couple to the supergravity formulation chosen, with or without a cosmological term. Finally, our linearized N=2 AdS supergravity action is reduced to N=1 superspace. The result is a sum of two N=1 linearized actions describing (i) old minimal supergravity; and (ii) an off-shell massless gravitino multiplet. We also derive dual formulations for the massless N=1 gravitino multiplet in AdS. As a by-product of our consideration, we derive the consistent supergravity extension of the N=1 ...
A Novel Approach for Attacks Mitigation in Mobile Ad Hoc Networks Using Cellular Automatas
Directory of Open Access Journals (Sweden)
Himadri Nath Saha
2012-04-01
Full Text Available Many security schemes for mobile ad-hoc network(MANET have been proposed so far but none of them has been successful in combating the different types of attacks that a mobile ad-hoc network often faces. This paper is providing one way of mitigating attacks in mobile ad-hoc networks by authenticating the node who tries to access this network .This scheme has been applied by using cellular automata (CA. Our simulation results show how cellular automata(CA is implemented for user authentication and secure transmission in MANET.
California Department of Resources — California Spatial Information System (CaSIL) is a project designed to improve access to geo-spatial and geo-spatial related data information throughout the state...
Production of high added value products from eggshells
Castro, Inês; Pinto, D. B.; Maciel, José; Araújo, Ana; Vicente, A.A.; Rocha, Cristina M. R.
2014-01-01
There are an increasing number of food companies addressing sustainable-manufacturing practices as part of social responsibility reporting. The egg processing industry produces several tons of eggshell residues which are a major environmental problem and represent a significant cost for these industries (ca. 0.6 % of sales). The main goal of this work is to produce high added value products, namely collagen and bioactive peptides, using the remnant of collagen extraction from the eggshell mem...
Entanglement Temperature and Perturbed AdS$_3$ Geometry
Levine, Gregory
2015-01-01
In analogy to the first law of thermodynamics, the increase in entanglement entropy $\\delta S$ of a conformal field theory (CFT) is proportional to the increase in energy, $\\delta E$, of the subsystem divided by an effective entanglement temperature, $T_E$. Extending this analogy, we study entanglement entropy when the subsystem is perturbed by applying an external field, expressed as a coupling to a local marginal operator in the CFT. We show that the resulting entropy change is associated with a change in the entanglement temperature itself, leading to an equation analogous to the Clausius relation. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature, $\\delta T_E(x)$ of the CFT and the perturbation of the bulk AdS metric. Using the AdS$_3$ minimal surface as a probe, we can construct bulk metric perturbations from an exact numerical computation of the entanglement temperature in a two dimensional $c=1$ boundary theory deformed by a marginal perturbati...
Ultraviolet asymptotics and singular dynamics of AdS perturbations
Craps, Ben; Vanhoof, Joris
2015-01-01
Important insights into the dynamics of spherically symmetric AdS-scalar field perturbations can be obtained by considering a simplified time-averaged theory accurately describing perturbations of amplitude epsilon on time-scales of order 1/epsilon^2. The coefficients of the time-averaged equations are complicated expressions in terms of the AdS scalar field mode functions, which are in turn related to the Jacobi polynomials. We analyze the behavior of these coefficients for high frequency modes. The resulting asymptotics can be useful for understanding the properties of the finite-time singularity in solutions of the time-averaged theory recently reported in the literature. We highlight, in particular, the gauge dependence of this asymptotics, with respect to the two most commonly used gauges. The harsher growth of the coefficients at large frequencies in higher-dimensional AdS suggests strengthening of turbulent instabilities in higher dimensions. In the course of our derivations, we arrive at recursive rel...
Effect of CaO composition on oxidation and burning behaviors of AM50 Mg alloy
Institute of Scientific and Technical Information of China (English)
Jin-Kyu LEE; Shae K. KIM
2011-01-01
Oxidation and burning behaviors were studied for CaO added AM50 Mg composites which were manufactured by conventional melting and casting processes without SF6 protective gas. CaO added AM50 Mg composites show the stable oxidation resistance. while AM50 Mg alloys show the poor oxidation resistance. The effects of CaO addition on the burning resistance under ambient, nitrogen and dry air atmospheres were examined for CaO added AM50 Mg composites. With increasing CaO addition, the burning temperature increases under ambient, nitrogen and dry air atmospheres. The burning temperatures of small test specimen under all conditions greatly increase even by 0.3% CaO (mass fraction) addition into AM50 Mg alloys.
Ca2+ paradox injury mediated through TRPC channels in mouse ventricular myocytes.
Kojima, Akiko; Kitagawa, Hirotoshi; Omatsu-Kanbe, Mariko; Matsuura, Hiroshi; Nosaka, Shuichi
2010-12-01
BACKGROUND AND PURPOSE The Ca(2+) paradox is an important phenomenon associated with Ca(2+) overload-mediated cellular injury in myocardium. The present study was undertaken to elucidate molecular and cellular mechanisms for the development of the Ca(2+) paradox. EXPERIMENTAL APPROACH Fluorescence imaging was performed on fluo-3 loaded quiescent mouse ventricular myocytes using confocal laser scanning microscope. KEY RESULTS The Ca(2+) paradox was readily evoked by restoration of the extracellular Ca(2+) following 10-20 min of nominally Ca(2+)-free superfusion. The Ca(2+) paradox was significantly reduced by blockers of transient receptor potential canonical (TRPC) channels (2-aminoethoxydiphenyl borate, Gd(3+), La(3+)) and anti-TRPC1 antibody. The sarcoplasmic reticulum (SR) Ca(2+) content, assessed by caffeine application, gradually declined during Ca(2+)-free superfusion, which was further accelerated by metabolic inhibition. Block of SR Ca(2+) leak by tetracaine prevented Ca(2+) paradox. The Na(+) /Ca(2+) exchange (NCX) blocker KB-R7943 significantly inhibited Ca(2+) paradox when applied throughout superfusion period, but had little effect when added for a period of 3 min before and during Ca(2+) restoration. The SR Ca(2+) content was better preserved during Ca(2+) depletion by KB-R7943. Immunocytochemistry confirmed the expression of TRPC1, in addition to TRPC3 and TRPC4, in mouse ventricular myocytes. CONCLUSIONS AND IMPLICATIONS These results provide evidence that (i) the Ca(2+) paradox is primarily mediated by Ca(2+) entry through TRPC (probably TRPC1) channels that are presumably activated by SR Ca(2+) depletion; and (ii) reverse mode NCX contributes little to the Ca(2+) paradox, whereas inhibition of NCX during Ca(2+) depletion improves SR Ca(2+) loading, and is associated with reduced incidence of Ca(2+) paradox in mouse ventricular myocytes.
Writing CFT correlation functions as AdS scattering amplitudes
Penedones, Joao
2010-01-01
We explore the Mellin representation of conformal correlation functions recently proposed by Mack. Examples in the AdS/CFT context reinforce the analogy between Mellin amplitudes and scattering amplitudes. We conjecture a simple formula relating the bulk scattering amplitudes to the asymptotic behavior of Mellin amplitudes and show that previous results on the flat space limit of AdS follow from our new formula. We find that the Mellin amplitudes are particularly useful in the case of conformal gauge theories in the planar limit. In this case, the four point Mellin amplitudes are meromorphic functions whose poles and their residues are entirely determined by two and three point functions of single-trace operators. This makes the Mellin amplitudes the ideal objects to attempt the conformal bootstrap program in higher dimensions.
Self-Dual Warped AdS$_3$ Black Holes
Chen, Bin; Ning, Bo
2010-01-01
We propose a new class of solutions of three-dimensional topological massive gravity. These solutions are non-extremal black holes, with their extremal counterparts being discrete quotients of spacelike warped AdS$_3$ along the $U(1)_L$ isometry. We study the thermodynamics of these black holes and show that the first law is satisfied. We also show that for consistent boundary conditions, the asymptotic symmetry generators form only one copy of the Virasoro algebra with central charge $c_L = \\frac{4\
Coherent Cascade: Collapsing Solutions in Global AdS
Freivogel, Ben
2015-01-01
We analyze the gravitational dynamics of a classical scalar field that sometimes leads to blackhole formation in asymptotically AdS spacetime at the shortest nonlinear time scale. We present strong evidence that the dynamics is governed by a "coherent cascade", with all modes remaining in phase as the energy flows to higher frequencies into a power-law spectrum. Using a coherent phase ansatz, we analytically find these power-law solutions. We show how the particular power is determined by the scaling properties of the interaction coefficients. Our result agrees with existing numerical results in 4+1 dimensions, and makes predictions in higher dimensions.
Entanglement Entropy and Duality in AdS(4)
Bakas, Ioannis
2015-01-01
Small variations of the entanglement entropy \\delta S and the expectation value of the modular Hamiltonian \\delta E are computed holographically for circular entangling curves in the boundary of AdS(4), using gravitational perturbations with general boundary conditions in spherical coordinates. Agreement with the first law of thermodynamics, \\delta S = \\delta E, requires that the line element of the entangling curve remains constant. In this context, we also find a manifestation of electric-magnetic duality for the entanglement entropy and the corresponding modular Hamiltonian, following from the holographic energy-momentum/Cotton tensor duality.
M-Theory solutions with AdS factors
Gauntlett, J P; Pakis, S; Waldram, D; Gauntlett, Jerome P.; Kim, Nakwoo; Pakis, Stathis; Waldram, Daniel
2002-01-01
Solutions of D=7 maximal gauged supergravity are constructed with metrics that are a product of a n-dimensional anti-de Sitter (AdS) space, with n=2,3,4,5, and certain Einstein manifolds. The gauge fields have the same form as in the recently constructed solutions describing the near-horizon limits of M5-branes wrapping supersymmetric cycles. The new solutions do not preserve any supersymmetry and can be uplifted to obtain new solutions of D=11 supergravity, which are warped and twisted products of the D=7 metric with a squashed four-sphere. Some aspects of the stability of the solutions are discussed.
M-theory solutions with AdS factors
Energy Technology Data Exchange (ETDEWEB)
Gauntlett, Jerome P [Department of Physics, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Kim, Nakwoo [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1, D-14476 Golm (Germany); Pakis, Stathis [Department of Physics, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom); Waldram, Daniel [Department of Physics, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)
2002-08-07
Solutions of D=7 maximal gauged supergravity are constructed with metrics that are a product of an n-dimensional anti-de Sitter (AdS) space, with n=2, 3, 4, 5, and certain Einstein manifolds. The gauge fields have the same form as in the recently constructed solutions describing the near-horizon limits of M5-branes wrapping supersymmetric cycles. The new solutions do not preserve any supersymmetry and can be uplifted to obtain new solutions of D=11 supergravity, which are warped and twisted products of the D=7 metric with a squashed four-sphere. Some aspects of the stability of the solutions are discussed.
Thermal Fluctuations in a Charged AdS Black Hole
Pourhassan, B
2015-01-01
In this paper, we will analyze the effects of thermal fluctuations on a charged AdS black hole. This will be done by analyzing the corrections to black hole thermodynamics due to these thermal fluctuations. We will demonstrate that the entropy of this black hole get corrected by logarithmic term. We will also calculate other corrections to other important thermodynamic quantities for this black hole. Finally, we will use the corrected value of the specific heat to analyze the phase transition in this system.
Duality invariance of s≥32 fermions in AdS
Directory of Open Access Journals (Sweden)
S. Deser
2014-11-01
Full Text Available We show that in D=4 AdS, s≥3/2 partially massless (PM fermions retain the duality invariances of their flat space massless counterparts. They have tuned ratios m2/M2≠0 that turn them into sums of effectively massless unconstrained helicity ±(s,⋯,32 excitations, shorn of the lowest (non-dual helicity ±12-rung and — more generally — of succeeding higher rung as well. Each helicity mode is separately duality invariant, like its flat space counterpart.
Small black holes in global AdS spacetime
Jokela, Niko; Pönni, Arttu; Vuorinen, Aleksi
2016-04-01
We study the properties of two-point functions and quasinormal modes in a strongly coupled field theory holographically dual to a small black hole in global anti-de Sitter spacetime. Our results are seen to smoothly interpolate between known limits corresponding to large black holes and thermal AdS space, demonstrating that the Son-Starinets prescription works even when there is no black hole in the spacetime. Omitting issues related to the internal space, the results can be given a field theory interpretation in terms of the microcanonical ensemble, which provides access to energy densities forbidden in the canonical description.
Internal Structure of Charged AdS Black Holes
Bhattacharjee, Srijit; Virmani, Amitabh
2016-01-01
When an electrically charged black hole is perturbed its inner horizon becomes a singularity, often referred to as the Poisson-Israel mass inflation singularity. Ori constructed a model of this phenomenon for asymptotically flat black holes, in which the metric can be determined explicitly in the mass inflation region. In this paper we implement the Ori model for charged AdS black holes. We find that the mass function inflates faster than the flat space case as the inner horizon is approached. Nevertheless, the mass inflation singularity is still a weak singularity: although spacetime curvature becomes infinite, tidal distortions remain finite on physical objects attempting to cross it.
AdS Chern-Simons Gravity induces Conformal Gravity
Aros, Rodrigo
2013-01-01
The leitmotif of this paper is the question of whether four- and higher even-dimensional Conformal Gravities do have a Chern-Simons pedigree. We show that Weyl gravity can be obtained as dimensional reduction of a five-dimensional Chern-Simons action for a suitable (gauged-fixed, tractor-like) five-dimensional AdS connection. The gauge-fixing and dimensional reduction program admits a readily generalization to higher dimensions for the case of certain conformal gravities obtained by contractions of the Weyl tensor.
Most general AdS_3 boundary conditions
Grumiller, Daniel
2016-01-01
We consider the most general asymptotically anti-de Sitter boundary conditions in three-dimensional Einstein gravity with negative cosmological constant. The metric contains in total twelve independent functions, six of which are interpreted as chemical potentials (or non-normalizable fluctuations) and the other half as canonical boundary charges (or normalizable fluctuations). Their presence modifies the usual Fefferman-Graham expansion. The asymptotic symmetry algebra consists of two sl(2)_k current algebras, the levels of which are given by k=l/(4G_N), where l is the AdS radius and G_N the three-dimensional Newton constant.
Belin, Alexandre; Hung, Ling-Yan
2015-01-01
We discuss properties of interpolating geometries in three dimensional gravity in the presence of a chiral anomaly. This anomaly, which introduces an unbalance between left and right central charges, is protected under RG flows. For this simple reason it is impossible to gap a system with such an anomaly. Our goal is to discuss how holography captures this basic and robust feature. We demonstrate the absence of a mass gap by analysing the linearized spectrum and holographic entanglement entropy of these backgrounds in the context of AdS$_3$/CFT$_2$.
ADS National Programmes: Russian Federation
International Nuclear Information System (INIS)
Studies on accelerator driven systems (ADS), which be used as burners of long lived radioactive waste accrued due to operation of thermal reactors, first of all, minor actinides (MA), are carried out in some Russian research institutes (ITEP, SSC RF - IPPE, VNIIEF, JINR, RSC KI, IYaI RAN, OKB ‘GIDROPRESS’, VNIITF etc.). These researches are mainly connected with studying physical processes existing in ADS and their parameters and with design studies and substantiation of experimental ADS facilities. One of the most important directions of researches is the acquirement of quite precise and reliable nuclear data on MA with reference to conditions existing in ADS. Now a coordinated programme of researches on measurement and estimation of nuclear data for 22 isotopes of U, Pu, Np, Am, Cm, Bk and Cf in neutron energy range from 0.05 eV up to 30 MeV has been prepared. Development of different variants of ADS has put a task of comparison of their efficiency as burners of MA
Accomazzi, Alberto; Kurtz, M. J.; Henneken, E. A.; Grant, C. S.; Thompson, D.; Luker, J.; Chyla, R.; Murray, S. S.
2014-01-01
In the spring of 1993, the Smithsonian/NASA Astrophysics Data System (ADS) first launched its bibliographic search system. It was known then as the ADS Abstract Service, a component of the larger Astrophysics Data System effort which had developed an interoperable data system now seen as a precursor of the Virtual Observatory. As a result of the massive technological and sociological changes in the field of scholarly communication, the ADS is now completing the most ambitious technological upgrade in its twenty-year history. Code-named ADS 2.0, the new system features: an IT platform built on web and digital library standards; a new, extensible, industrial strength search engine; a public API with various access control capabilities; a set of applications supporting search, export, visualization, analysis; a collaborative, open source development model; and enhanced indexing of content which includes the full-text of astronomy and physics publications. The changes in the ADS platform affect all aspects of the system and its operations, including: the process through which data and metadata are harvested, curated and indexed; the interface and paradigm used for searching the database; and the follow-up analysis capabilities available to the users. This poster describes the choices behind the technical overhaul of the system, the technology stack used, and the opportunities which the upgrade is providing us with, namely gains in productivity and enhancements in our system capabilities.
No Holography for Eternal AdS Black Holes
Avery, Steven G
2013-01-01
It is generally believed that the eternal AdS black hole is dual to two conformal field theories with compact spatial sections that are together in a thermofield double state. We argue that this proposal is incorrect, and by extension so are the "entanglement=geometry" proposal of Van Raamsdonk and "ER=EPR" proposal of Maldacena and Susskind. We show that in the bulk there is an interaction needed between the two halves of the Hilbert space for connectivity across the horizon; however, there is no such interaction between the CFTs. This rules out the possibility of the dual to the CFTs being the eternal AdS black hole. We argue the correct dual "geometries" resemble the exterior of the black hole outside the stretched horizon but cap off before the global horizon. This disallows the possibility of a shared future (and past) wedge where Alice falling from one side can meet Bob falling from the other. We expect that in the UV complete theory the aforementioned caps will be fuzzballs.
Quantum cat map dynamics on AdS$_2$
Axenides, Minos; Nicolis, Stam
2016-01-01
We present a toy model for the chaotic unitary scattering of single particle wave packets on the radial AdS$_2$ geometry of extremal BH horizons. Based on our recent work for the discretization of the AdS$_2$ space-time, which describes a finite and random geometry, by modular arithmetic, we investigate the validity of the eigenstate thermalization hypothesis (ETH), as well as that of the fast scrambling time bound conjecture (STB), for an observer with time evolution operator the quantum Arnol'd cat map (QACM). We find that the QACM, while possessing a linear spectrum, has eigenstates, which can be expressed in closed form, are found to be random and to satisfy the assumptions of the ETH.The implications are that the dynamics is described by a chaotic, unitary, single particle S-matrix, which completely delocalizes and randomizes initial gaussian wave packets . Applying results obtained by Dyson and Falk for the periods of the Arnol'd Cat Map(ACM),which are related to its mixing time, we also find that the t...
AdS Twistors for Higher Spin Theory
International Nuclear Information System (INIS)
We construct spectra of supersymmetric higher spin theories in D = 4, 5 and 7 from twistors describing massless (super-)particles on AdS spaces. A massless twistor transform is derived in a geometric way from classical kinematics. Relaxing the spin-shell constraints on twistor space gives an infinite tower of massless states of a 'higher spin particle', generalizing previous work of Bandos et al.. This can generically be done in a number of ways, each defining the states of a distinct higher spin theory, and the method provides a systematic way of finding these. We reproduce known results in D = 4, minimal supersymmetric 5- and 7-dimensional models, as well as supersymmetrisations of Vasiliev's Sp-models as special cases. In the latter models a dimensional enhancement takes place, meaning that the theory lives on a space of higher dimension than the original AdS space, and becomes a theory of doubletons. This talk was presented at the XIX-th Max Born Symposium 'Fundamental Interactions and Twistor-Like Methods', September 2004, in Wroclaw, Poland
AdCell: Ad Allocation in Cellular Networks
Alaei, Saeed; Liaghat, Vahid; Pei, Dan; Saha, Barna
2011-01-01
With more than four billion usage of cellular phones worldwide, mobile advertising has become an attractive alternative to online advertisements. In this paper, we propose a new targeted advertising policy for Wireless Service Providers (WSPs) via SMS or MMS- namely {\\em AdCell}. In our model, a WSP charges the advertisers for showing their ads. Each advertiser has a valuation for specific types of customers in various times and locations and has a limit on the maximum available budget. Each query is in the form of time and location and is associated with one individual customer. In order to achieve a non-intrusive delivery, only a limited number of ads can be sent to each customer. Recently, new services have been introduced that offer location-based advertising over cellular network that fit in our model (e.g., ShopAlerts by AT&T) . We consider both online and offline version of the AdCell problem and develop approximation algorithms with constant competitive ratio. For the online version, we assume tha...
Smooth Causal Patches for AdS Black Holes
Raju, Suvrat
2016-01-01
We review the paradox of low energy excitations about an AdS black hole. An appropriately chosen unitary operator in the boundary theory can create a locally strong excitation near the black hole horizon, whose global energy is small as a result of the gravitational redshift. The paradox is that this seems to violate a general rule of statistical mechanics, which states that an operator with energy parametrically smaller than $k T$ cannot create a significant excitation in a thermal system. When we carefully examine the position dependence of the boundary unitary operator that produces the excitation and the bulk observable necessary to detect the anomalously large effect, we find that they do not both fit in a single causal patch. This follows from a remarkable property of position space AdS correlators that we establish explicitly, and resolves the paradox in a generic state of the system, since no combination of observers can both create the excitation and observe its effect. As a special case of our analy...
Facilities Management and Added Value
DEFF Research Database (Denmark)
Jensen, Per Anker
2010-01-01
Aim: This paper aims to present different models of the concept of the added value of Facilities Management (FM), including the FM Value Map, which forms the basis of research group in EuroFM, and to present some of the results of this research collaboration. Approach and methodology: The paper...... is based on literature reviews of the most influential journals within the academic fields of FM, Corporate Real Estate Management and Business to Business Marketing and discussions between participants of the research group working on a further exploration and testing of the FM Value Map. Conclusions......: The research shows a number of different definitions and focus points of Added Value of FM, dependent on the academic field and the area of application. The different research perspectives explored a holistic view on the added value of FM by the integration of an external market based view (with a focus...
Online Ad Slotting With Cancellations
Constantin, Florin; Muthukrishnan, S; Pal, Martin
2008-01-01
Many advertisers buy advertisements (ads) on the Internet or on traditional media and seek simple, online mechanisms to reserve ad slots in advance. Media publishers represent a vast and varying inventory, and they too seek automatic, online mechanisms for pricing and allocating such reservations. In this paper, we present and study a simple model for auctioning such ad slots in advance. Bidders arrive sequentially and report which slots they are interested in. The seller must decide immediately whether or not to grant a reservation. Our model allows a seller to accept reservations, but possibly cancel the allocations later and pay the bidder a cancellation compensation (bump payment). Our main result is an online mechanism to derive prices and bump payments that is efficient to implement. This mechanism has many desirable properties. It is individually rational; winners have an incentive to be honest and bidding one's true value dominates any lower bid. Our mechanism's efficiency is within a constant fractio...
Role of Ca resistance in competitive survival of fluorescent Pseudomonas in soil with high salinity
International Nuclear Information System (INIS)
The Ca2+-resistant strain HR2-6 of Pseudomonas putida was isolated from spinach root grown in a greenhouse in high salinity soil. Since Ca often accumulates in greenhouse soils in Japan due to many years of Ca applications, the role of Ca2+ resistance in the survival of the strain was investigated. To conduct the investigation, Ca2+-sensitive mutants were obtained with UV-irradiation. The Ca2+-sensitive mutant CAS-1 was found to grow as well as the wild type HR2-6 in a TSB medium without added Ca2+, but with 150 mM and 200 mM Ca2+ added, the growth of the Ca2+-sensitive mutants were 7- and 56-fold lower than that of the wild type. In sterile spinach-greenhouse soil (a non-competitive environment), populations of the Ca2+-sensitive mutant and wild-type strain were similar, but in nonsterile greenhouse soil (a competitive environment), populations of the Ca2+-sensitive mutant were 112-fold lower than the wild type after 50 days. These data suggest that Ca2+ resistance can be an important factor in the survival of P. putida in soil that has an accumulation of Ca
International Nuclear Information System (INIS)
Conclusions: • The YALINA facility is a unique installation which was designed as a zero power model of real ADS. • It is intended to study neutronics and kinetics of the sub-critical reactors driven by external neutron sources. • The successful operation of this facility is a scientific contribution from the Republic of Belarus, as well as the international team from EC and USA. • The experimental data are used to benchmark and validate methods and computer codes for designing and licensing ADS
Adding momentum to supersymmetric geometries
Energy Technology Data Exchange (ETDEWEB)
Lunin, Oleg, E-mail: olunin@albany.edu [Department of Physics, University at Albany (SUNY), Albany, NY 12222 (United States); Mathur, Samir D., E-mail: mathur.16@osu.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States); Turton, David, E-mail: turton.7@osu.edu [Department of Physics, Ohio State University, Columbus, OH 43210 (United States)
2013-03-11
We consider general supersymmetric solutions to minimal supergravity in six dimensions, trivially lifted to IIB supergravity. To any such solution we add a traveling wave deformation involving the additional directions. The deformed solution is given in terms of a function which is harmonic in the background geometry. We also present a family of explicit examples describing microstates of the D1-D5 system on T{sup 4}. In the case where the background contains a large AdS region, the deformation is identified as corresponding to an action of a U(1) current of the D1-D5 orbifold CFT on a given state.
Adding momentum to supersymmetric geometries
Lunin, Oleg; Turton, David
2012-01-01
We consider general supersymmetric solutions to minimal supergravity in six dimensions, trivially lifted to IIB supergravity. To any such solution we add a travelling-wave deformation involving the additional directions. The deformed solution is given in terms of a function which is harmonic in the background geometry. We also present a family of explicit examples describing microstates of the D1-D5 system on T^4. In the case where the background contains a large AdS region, the deformation is identified as corresponding to an action of a U(1) current of the D1-D5 orbifold CFT on a given state.
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
@@ 什么是CA? CA(Certificaton Authority)是认证机构的国际通称,是指对数字证书的申请者发放、管理、取消数字证书的机构.CA的作用是检查证书持有者身份的合法性,并签发证书(在证书上签字),以防证书被伪造或篡改.
DEFF Research Database (Denmark)
Antila, Kari; Lötjönen, Jyrki; Thurfjell, Lennart;
2013-01-01
Alzheimer's disease (AD) is the most common cause of dementia affecting 36 million people worldwide. As the demographic transition in the developed countries progresses towards older population, the worsening ratio of workers per retirees and the growing number of patients with age-related illnes...
Holographic properties in three-dimensional AdS soliton using $AdS_3/CFT_2$
Peng, Yan
2016-01-01
We study the holographic description of a superconductor by the $AdS_{3}/CFT_{2}$ correspondence. The system is constructed with a Maxwell field and a charged scalar field coupled in the (2+1)-dimensional AdS soliton background. With analytical methods, we obtain the exact expression for the critical chemical potential as $\\mu_{c} = 1 + \\sqrt{1+m^2}$, which has also been generalized to higher dimensions as $\\mu_c \\thickapprox a + \\sqrt{m^2-m_{BF}^2}$ in this work. Around the phase transition points, we find a correspondence between the value of the scalar field at the tip and the scalar operator at infinity. We also arrive at the classical second order phase transition threshold exponent $\\beta=\\frac{1}{2}$ as the same as the mean field theory near the critical chemical potential. As the condensation becomes heavier, we show surprisingly that superconducting phases exist only in a certain range of the chemical potential, which is very different from higher-dimensional cases. And for the small enough negative ...
D. David (David); L.F. Hoogerheide (Lennart); H.K. van Dijk (Herman)
2008-01-01
textabstractThis short note presents the R package AdMit which provides flexible functions to approximate a certain target distribution and it provides an efficient sample of random draws from it, given only a kernel of the target density function. The estimation procedure is fully automatic and thu
Anti-tumor activity of self-charged (Eu,Ca):WO3 and Eu:CaWO4 nanoparticles
Indian Academy of Sciences (India)
Cao Lin; Cao Jiexin; Wang Cong; Che Ping; Pan De’an; Alex A Volinsky
2012-10-01
Non-stoichiometric (Eu,Ca):WO3 and Eu:CaWO4 nanoparticles with anti-tumor activity are synthesized in a sol–gel method by adding excessive Eu3+ and Ca2+ ions to tungsten oxide crystal structure. Colorimetric assay shows that 10 nm (Eu,Ca):WO3 and Eu:CaWO4 nanoparticles can effectively inhibit growth of mammary cancer cells without any harm to normal cells. Nanoparticles are characterized by X-ray diffraction, high resolution transmission electron microscopy and fluorescence optical spectrometry. Nanomaterials, insoluble in synthesized water, have complicated self-charging surfaces that trap mammary cancer cells. Surface self-charging effect is suggested as the inhibition mechanism.
Bootstrapping Pure Quantum Gravity in AdS3
Bae, Jin-Beom; Lee, Sungjay
2016-01-01
The three-dimensional pure quantum gravity with negative cosmological constant is supposed to be dual to the extremal conformal field theory of central charge $c=24k$ in two dimensions. We employ the conformal bootstrap method to analyze the extremal CFTs, and find numerical evidence for the non-existence of the extremal CFTs for sufficiently large central charge ($k \\ge 20$). We also explore near-extremal CFTs, a small modification of extremal ones, and find similar evidence for their non-existence for large central charge. This indicates, under the assumption of holomorphic factorization, the pure gravity in the weakly curved AdS$_3$ do not exist as a consistent quantum theory.
On Information Loss in AdS$_3$/CFT$_2$
Fitzpatrick, A Liam; Li, Daliang; Wang, Junpu
2016-01-01
We discuss information loss from black hole physics in AdS$_3$, focusing on two sharp signatures infecting CFT$_2$ correlators at large central charge $c$: 'forbidden singularities' arising from Euclidean-time periodicity due to the effective Hawking temperature, and late-time exponential decay in the Lorentzian region. We study an infinite class of examples where forbidden singularities can be resolved by non-perturbative effects at finite $c$, and we show that the resolution has certain universal features that also apply in the general case. Analytically continuing to the Lorentzian regime, we find that the non-perturbative effects that resolve forbidden singularities qualitatively change the behavior of correlators at times $t \\sim S_{BH}$, the black hole entropy. This may resolve the exponential decay of correlators at late times in black hole backgrounds. By Borel resumming the $1/c$ expansion of exact examples, we explicitly identify 'information-restoring' effects from heavy states that should correspo...
An Investigation of AdS2 Backreaction and Holography
Engelsöy, Julius; Verlinde, Herman
2016-01-01
We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski and develop an 1D effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1D version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.
Correlation Functions of Winding Strings in AdS_3
Minces, Pablo
2008-01-01
We review certain results for amplitudes of spectral flowed operators in string theory on AdS_3. We present the modified Knizhnik-Zamolodchikov and null vector equations to be satisfied by correlators including w=1 operators. We then discuss the three point function of two w=1 and one w=0 operators in the x-basis, and perform a consistency check on the definition of the w=1 operator. We finally exhibit the steps in the calculation of the winding conserving four point functions for operators in arbitrary spectral flowed sectors, both in the m- and x-basis, under the only assumption that at least one of the operators is in the spectral flowed image of the highest weight discrete representation.
Thermodynamics of charged Lovelock: AdS black holes
Energy Technology Data Exchange (ETDEWEB)
Prasobh, C.B.; Suresh, Jishnu; Kuriakose, V.C. [Cochin University of Science and Technology, Department of Physics, Cochin (India)
2016-04-15
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime. (orig.)
Thermodynamics of charged Lovelock: AdS black holes
Prasobh, C. B.; Suresh, Jishnu; Kuriakose, V. C.
2016-04-01
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.
Thermodynamics of charged Lovelock: AdS black holes
International Nuclear Information System (INIS)
We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second-order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime. (orig.)
An investigation of AdS2 backreaction and holography
Engelsöy, Julius; Mertens, Thomas G.; Verlinde, Herman
2016-07-01
We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski [1] and develop a 1d effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1d version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.
International Programmes on ADS: The Asian ADS Network
International Nuclear Information System (INIS)
As the management of radioactive wastes is a common issue for all the countries utilizing nuclear energy and also for those intending to start it, international multilateral collaboration must be of great importance for effective research and development of transmutation technology for long lived nuclides. Collaboration in Asian region, however, had been less active in comparison to European countries, though nuclear power generation would increase significantly in Asia. Considering this context, the former Japan Atomic Energy Research Institute (JAERI) convened the ‘International Symposium on Accelerator driven Transmutation Systems and Asia ADS Network Initiative’ on March 24 and 25, 2003 at Tokyo, Japan in cooperation with Kyoto University, Osaka University, High Energy Accelerator Research Organization and Tokyo Institute of Technology. Through the discussion in the symposium, common understanding was developed in Japanese, Korean and Chinese scientists concerning the importance of establishing an international network among Asian countries to facilitate information exchange for R&D of ADS. Based on this understanding, five workshops were held so far. The workshop covers the national R&D programmes on ADS including subcritical reactor physics, cross-section measurements, high energy particle physics, accelerator technology, material technology and MA fuel technology. From the fifth workshop, information exchange for R&D on innovative fast reactors for nuclear transmutation was also included
Energy Technology Data Exchange (ETDEWEB)
Fitzpatrick, A.Liam; /Boston U.; Kaplan, Jared; /SLAC
2012-02-14
We show that suitably regulated multi-trace primary states in large N CFTs behave like 'in' and 'out' scattering states in the flat-space limit of AdS. Their transition matrix elements approach the exact scattering amplitudes for the bulk theory, providing a natural CFT definition of the flat space S-Matrix. We study corrections resulting from the AdS curvature and particle propagation far from the center of AdS, and show that AdS simply provides an IR regulator that disappears in the flat space limit.
Functional foods for added value
Mark-Herbert, Cecilia
2002-01-01
In this study innovation involves the development of a new product category; i.e. new products, new processes and new business. The development process is conveyed in narratives where a radically new product group, functional foods, is developed. These high-tech food products are associated with added value for the food business as well as for individuals and society at large. In the past decades Swedish food companies have faced an increasing competition. With increased competitive pressures...
International Programmes on ADS: ISTC
International Nuclear Information System (INIS)
The International Science and Technology Center (ISTC) is an intergovernmental organization, created to serve the goal of improving global safety and security. The European Union, Japan, the Russian Federation and the United States of America, on the basis of a multinational agreement, established ISTC in 1992. The ISTC focused its efforts on funding research projects related to key safety and security technologies including advanced nuclear technology. Since the first ISTC funded project in 1994, Accelerator Driven Systems, Transmutation research and a holistic approach to the nuclear fuel cycle were the areas where ISTC made a real impact on international development in these fields. Given the international dimension of the problem, the research communities of the ISTC member states quickly realized that ISTC projects offered a very flexible and fruitful cooperation platform to address many difficult issues of the nuclear fuel cycle. Highly competent expert communities of ISTC member states benefited from a well defined and transparent mode of operation of ISTC and objective oriented project funding strategy. The ISTC projects related to transmutation of radioactive waste and ADS can be classified in the following thematic areas: - ADS concepts; - Accelerator development; - Spallation target studies; - Nuclear data and spallation process studies; - Minor actinides studies related to ADS; - Partitioning and extraction
Directory of Open Access Journals (Sweden)
J. Swart
1988-09-01
Full Text Available As instructed by the Central Board of the South African Nursing Association during 1985, an investigation was launched into the function of the C.A. Not hard Library, namely to provide optimal information to members. The underlying philosophy concerned with the establishment of the library was to provide a service which is not available elsewhere. The investigation revealed however, that various training institutions in the country meet this need. As a result of the findings, as presented in the article, the C.A. Northard Library was closed on 1 December 1985 as a lending library. A unique Nursing reference library is being established in its place, with the emphasis in the future on the S. A. Nursing Association’s role in the promotion of Nursing research.
Magnetic Mass in 4D AdS Gravity
Araneda, Rene; Miskovic, Olivera; Olea, Rodrigo
2016-01-01
We provide a fully-covariant expression for the diffeomorphic charge in 4D anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to the action. The couplings of these topological invariants are such that the Weyl tensor and its dual appear in the on-shell variation of the action, and such that the action is stationary for asymptotic (anti) self-dual solutions in the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the self-duality condition is global, both the action and the total charge are identically vanishing. Therefore, for such configurations the magnetic mass equals the Ashtekhar-Magnon-Das definition.
Magnetic mass in 4D AdS gravity
Araneda, René; Aros, Rodrigo; Miskovic, Olivera; Olea, Rodrigo
2016-04-01
We provide a fully covariant expression for the diffeomorphic charge in four-dimensional anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to the action. The couplings of these topological invariants are such that the Weyl tensor and its dual appear in the on-shell variation of the action and such that the action is stationary for asymptotic (anti-)self-dual solutions in the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the self-duality condition is global, both the action and the total charge are identically vanishing. Therefore, for such configurations, the magnetic mass equals the Ashtekhar-Magnon-Das definition.
Towards Timelike Singularity via AdS Dual
Bhowmick, Samrat
2016-01-01
It is well known that Kasner geometry with spacelike singularity can be extended to bulk AdS-like geometry, furthermore one can study field theory on this Kasner space via its gravity dual. In this paper, we show that there exists a Kasner-like geometry with timelike singularity for which one can construct a dual gravity description. We then study various minimal surfaces including spacelike geodesics. Finally, we compute correlators of highly massive operators in the boundary field theory with a geodesic approximation.
Canonical energy and hairy AdS black holes
Hyun, Seungjoon; Park, Sang-A.; Yi, Sang-Heon
2016-08-01
We propose the modified version of the canonical energy which was introduced originally by Hollands and Wald. Our construction depends only on the Euler-Lagrange expression of the system and thus is independent of the ambiguity in the Lagrangian. After some comments on our construction, we briefly mention on the relevance of our construction to the boundary information metric in the context of the AdS/CFT correspondence. We also study the stability of three-dimensional hairy extremal black holes by using our construction.
International Nuclear Information System (INIS)
We present a comprehensive analysis of the AdS/Ricci-flat correspondence, a map between a class of asymptotically locally AdS spacetimes and a class of Ricci-flat spacetimes. We provide a detailed derivation of the map, discuss a number of extensions and apply it to a number of important examples, such as AdS on a torus, AdS black branes and fluids/gravity metrics. In particular, the correspondence links the hydrodynamic regime of asymptotically flat black p-branes or the Rindler fluid with that of AdS. It implies that this class of Ricci-flat spacetimes inherits from AdS a generalized conformal symmetry and has a holographic structure. We initiate the discussion of holography by analyzing how the map acts on boundary conditions and holographic 2-point functions
Sulfide capacities of CaO-CaF2-CaCl2 melts
Simeonov, Simeon; Sakai, Toshihiko; Maeda, Masafumi
1992-06-01
The sulfide capacityC_{s^{2 - } } = ({text{pct S}}^{{text{2 - }}} )(p_{{text{O}}_{text{2}} } /p_{{text{S}}_{text{2}} } )^{1/2} ) of CaO-CaF2-CaCl2 slag was determined at temperatures from 1000 °C to 1300 °C by equilibrating molten slag, molten silver, and CO-CO2-Ar gas mixture. The sulfide capacity increases with replacing CaCl2 by CaF2 in slags of constant CaO contents. The sulfide capacity also increases with increasing temperature as well as with increasing CaO content at a constant ratio of CaF2/CaCl2 of unity. A linear relationship between the sulfide capacity and carbonate capacity in literature was observed on a logarithmic scale.
Stability of charged global AdS4 spacetimes
Arias, Raúl; Mas, Javier; Serantes, Alexandre
2016-09-01
We study linear and nonlinear stability of asymptotically AdS4 solutions in Einstein-Maxwell-scalar theory. After summarizing the set of static solutions we first examine thermodynamical stability in the grand canonical ensemble and the phase transitions that occur among them. In the second part of the paper we focus on nonlinear stability in the microcanonical ensemble by evolving radial perturbations numerically. We find hints of an instability corner for vanishingly small perturbations of the same kind as the ones present in the uncharged case. Collapses are avoided, instead, if the charge and mass of the perturbations come to close the line of solitons. Finally we examine the soliton solutions. The linear spectrum of normal modes is not resonant and instability turns on at extrema of the mass curve. Linear stability extends to nonlinear stability up to some threshold for the amplitude of the perturbation. Beyond that, the soliton is destroyed and collapses to a hairy black hole. The relative width of this stability band scales down with the charge Q, and does not survive the blow up limit to a planar geometry.
Stability of Charged Global AdS$_4$ Spacetimes
Arias, Raúl; Serantes, Alexandre
2016-01-01
We study linear and nonlinear stability of asymptotically AdS$_4$ solutions in Einstein-Maxwell-scalar theory. After summarizing the set of static solutions we first examine thermodynamical stability in the grand canonical ensemble and the phase transitions that occur among them. In the second part of the paper we focus on nonlinear stability in the microcanonical ensemble by evolving radial perturbations numerically. We find hints of an instability corner for vanishingly small perturbations of the same kind as the ones present in the uncharged case. Collapses are avoided, instead, if the charge and mass of the perturbations come to close the line of solitons. Finally we examine the soliton solutions. The linear spectrum of normal modes is not resonant and instability turns on at extrema of the mass curve. Linear stability extends to nonlinear stability up to some threshold for the amplitude of the perturbation. Beyond that, the soliton is destroyed and collapses to a hairy black hole. The relative width of t...
Goodman, Alyssa
We will create the first interactive sky map of astronomers' understanding of the Universe over time. We will accomplish this goal by turning the NASA Astrophysics Data System (ADS), widely known for its unrivaled value as a literature resource, into a data resource. GIS and GPS systems have made it commonplace to see and explore information about goings-on on Earth in the context of maps and timelines. Our proposal shows an example of a program that lets a user explore which countries have been mentioned in the New York Times, on what dates, and in what kinds of articles. By analogy, the goal of our project is to enable this kind of exploration-on the sky-for the full corpus of astrophysical literature available through ADS. Our group's expertise and collaborations uniquely position us to create this interactive sky map of the literature, which we call the "ADS All-Sky Survey." To create this survey, here are the principal steps we need to follow. First, by analogy to "geotagging," we will "astrotag," the ADS literature. Many "astrotags" effectively already exist, thanks to curation efforts at both CDS and NED. These efforts have created links to "source" positions on the sky associated with each of the millions of articles in the ADS. Our collaboration with ADS and CDS will let us automatically extract astrotags for all existing and future ADS holdings. The new ADS Labs, which our group helps to develop, includes the ability for researchers to filter article search results using a variety of "facets" (e.g. sources, keywords, authors, observatories, etc.). Using only extracted astrotags and facets, we can create functionality like what is described in the Times example above: we can offer a map of the density of positions' "mentions" on the sky, filterable by the properties of those mentions. Using this map, researchers will be able to interactively, visually, discover what regions have been studied for what reasons, at what times, and by whom. Second, where
Stabilizing ER Ca2+ channel function as an early preventative strategy for Alzheimer's disease.
Directory of Open Access Journals (Sweden)
Shreaya Chakroborty
Full Text Available Alzheimer's disease (AD is a devastating neurodegenerative condition with no known cure. While current therapies target late-stage amyloid formation and cholinergic tone, to date, these strategies have proven ineffective at preventing disease progression. The reasons for this may be varied, and could reflect late intervention, or, that earlier pathogenic mechanisms have been overlooked and permitted to accelerate the disease process. One such example would include synaptic pathology, the disease component strongly associated with cognitive impairment. Dysregulated Ca(2+ homeostasis may be one of the critical factors driving synaptic dysfunction. One of the earliest pathophysiological indicators in mutant presenilin (PS AD mice is increased intracellular Ca(2+ signaling, predominantly through the ER-localized inositol triphosphate (IP(3 and ryanodine receptors (RyR. In particular, the RyR-mediated Ca(2+ upregulation within synaptic compartments is associated with altered synaptic homeostasis and network depression at early (presymptomatic AD stages. Here, we offer an alternative approach to AD therapeutics by stabilizing early pathogenic mechanisms associated with synaptic abnormalities. We targeted the RyR as a means to prevent disease progression, and sub-chronically treated AD mouse models (4-weeks with a novel formulation of the RyR inhibitor, dantrolene. Using 2-photon Ca(2+ imaging and patch clamp recordings, we demonstrate that dantrolene treatment fully normalizes ER Ca(2+ signaling within somatic and dendritic compartments in early and later-stage AD mice in hippocampal slices. Additionally, the elevated RyR2 levels in AD mice are restored to control levels with dantrolene treatment, as are synaptic transmission and synaptic plasticity. Aβ deposition within the cortex and hippocampus is also reduced in dantrolene-treated AD mice. In this study, we highlight the pivotal role of Ca(2+ aberrations in AD, and propose a novel strategy to
Medvedeva, Yuliya V; Weiss, John H
2014-08-01
Ca(2+) and Zn(2+) have both been implicated in the induction of acute ischemic neurodegeneration. We recently examined changes in intracellular Zn(2+) and Ca(2+) in CA1 pyramidal neurons subjected to oxygen glucose deprivation (OGD), and found that Zn(2+) rises precede and contribute to the onset of terminal Ca(2+) rises ("Ca(2+) deregulation"), which are causatively linked to a lethal loss of membrane integrity. The present study seeks to examine the specific role of intramitochondrial Zn(2+) accumulation in ischemic injury, using blockers of the mitochondrial Ca(2+) uniporter (MCU), through which both Zn(2+) and Ca(2+) appear able to enter the mitochondrial matrix. In physiological extracellular Ca(2+), treatment with the MCU blocker, Ruthenium Red (RR), accelerated the Ca(2+) deregulation, most likely by disrupting mitochondrial Ca(2+) buffering and thus accelerating the lethal cytosolic Ca(2+) overload. However, when intracellular Ca(2+) overload was slowed, either by adding blockers of major Ca(2+) entry channels or by lowering the concentration of Ca(2+) in the extracellular buffer, Ca(2+) deregulation was delayed, and under these conditions either Zn(2+) chelation or MCU blockade resulted in similar further delays of the Ca(2+) deregulation. In parallel studies using the reactive oxygen species (ROS) indicator, hydroethidine, lowering Ca(2+) surprisingly accelerated OGD induced ROS generation, and in these low Ca(2+) conditions, either Zn(2+) chelation or MCU block slowed the ROS generation. These studies suggest that, during acute ischemia, Zn(2+) entry into mitochondria via the MCU induces mitochondrial dysfunction (including ROS generation) that occurs upstream of, and contributes to the terminal Ca(2+) deregulation.
International Programmes on ADS: IAEA
International Nuclear Information System (INIS)
The IAEA recognizes that there are four major challenges facing the long term development of nuclear energy as a part of the world’s energy mix: improvement of the economic competitiveness, meeting increasingly stringent safety requirements, adhering to the criteria of sustainable development, and public acceptance. Meeting the sustainability criteria is the driving force behind IAEA’s activity in the area of innovative transmutation reactor technology development and, in particular, Accelerator Driven Systems. The framework for all the IAEA activities in the ADS area is the Technical Working Group on Fast Reactors (TWG-FR). In response to strong common R&D needs in the Member States, the TWG-FR acts as a catalyst for international information exchange and collaborative R&D. It provides a forum for exchange of non-commercial scientific and technical information, and a forum for international cooperation on generic research and development programmes on advances in fast reactors and fast spectrum accelerator driven systems. Its present members are the following 15 IAEA Member States: Belarus, Brazil, China, France, Germany, India, Italy, Japan, Kazakhstan, Republic of Korea, Russian Federation, Sweden, Switzerland, United Kingdom, and United States of America, as well as 3 international organizations: ISTC, OECD-NEA, and EU (EC). As observers, the TWG-FR has welcomed Argentina and Belgium. Last but not least, the IAEA is providing the ADS Research and Development Database. It contains information about ADS related R&D programmes, existing and planned experimental facilities as well as programmes, methods and data development efforts, design studies, and so forth
ADS activities in the Netherlands
International Nuclear Information System (INIS)
The problem of long-lived nuclear waste was under consideration in the Netherlands during a number of years. Within this framework different reactor concepts have been considered. One of the most promising concepts appears to be the Accelerator Driven System (ADS) or Fast Energy Amplifier (FEA), as it has been proposed by C. Rubbia of CERN. To unite the effort on accelerator driven reactor concepts in the Netherlands, KEMA, NIKHEF, ECN, KVI, and IRI have joined their forces in a co-operative program since 1996. Cupertino covers the technical fields of nuclear data, reactor physics, and innovative fuels. (author)
Sembiring, Firdaus
2011-01-01
The prepared of film coating calcium alginate chitosan with examined the characteristic has been studied. Making of the film coating performed with interaction polikationik chitosan and polianionik alginate, then added with CaCl2 so that forms astringent. Khelat Ca-alginat chitosan has thickness of 200µm. Analysis SEM shows surface morphology of Ca-alginat chitosan experiences creasing at its surface after experiencing diffusion. Effectivity test Ca-alginat chitosan proved from broadness free...
Context: The effect of added sugar intake on ectopic fat accumulation is a subject of debate. Objective: A systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to examine the potential effect of added sugar intake on ectopic fat depots. Data Sources: MEDLINE, CA...
Entanglement Entropy of AdS Black Holes
Directory of Open Access Journals (Sweden)
Maurizio Melis
2010-11-01
Full Text Available We review recent progress in understanding the entanglement entropy of gravitational configurations for anti-de Sitter gravity in two and three spacetime dimensions using the AdS/CFT correspondence. We derive simple expressions for the entanglement entropy of two- and three-dimensional black holes. In both cases, the leading term of the entanglement entropy in the large black hole mass expansion reproduces exactly the Bekenstein-Hawking entropy, whereas the subleading term behaves logarithmically. In particular, for the BTZ black hole the leading term of the entanglement entropy can be obtained from the large temperature expansion of the partition function of a broad class of 2D CFTs on the torus.
1987-02-20
3 CBS-owned television stations and NBC's New York television station announced yesterday that they would begin accepting condom advertising. In addition, the ABC network announced it will begin running a 30-second public service message with Dr. C. Everett Koop, the US surgeon general, saying that condoms are the best protection against sexual transmission of AIDS. CBS said it will allow the 4 television stations and 18 radio stations it owns to accept condom advertising based on the attitudes of the local viewing or listening community. WCBS-TV in New York, WCAU-TV in Philadelphia and KCBS-TV in Los Angeles said they would accept such ads. CBS also owns a television station in Chicago. WCAU will air condom ads after 11 p.m. only, beginning probably next week, said Paul Webb, a station spokesman. "We recognize the legitimate sensitivities of some members of the community in regard to this issue," said Steve Cohen, the WCAU general manager. "However, it is the judgment of this station that the importance of providing information about the AIDS epidemic and means of prevention is an overriding consideration." NBC's New York television station, WNBC, announced that it will accept condom advertising and public service announcements. PMID:12269166
Axenides, Minos; Linardopoulos, Georgios
2013-01-01
We study membrane configurations in AdS_{7/4}xS^{4/7}. The membranes are wrapped around the compact manifold S^{4/7} and are dynamically equivalent to bosonic strings in AdS_5. We thus conveniently identify them as "stringy membranes". For the case of AdS_7xS^4, their construction is carried out by embedding the Polyakov action for classical bosonic strings in AdS_5, into the corresponding membrane action. Therefore, every string configuration in AdS_5 can be realized by an appropriately chosen stringy membrane in AdS_7xS^4. We discuss the possibility of this being also the case for stringy membranes in AdS_4xS^7/Z^k (k > 1 or k = 1). By performing a stability analysis to the constructed solutions, we find that the (membrane) fluctuations along their transverse directions are organized in multiple Lam\\'{e} stability bands and gaps in the space of parameters of the configurations. In this membrane picture, strings exhibit a single band/gap structure. Since the spectrum of quadratic fluctuations is important fo...
DEFF Research Database (Denmark)
Schröder, Philipp J.H.; Sørensen, Allan
2010-01-01
Real-world industries are composed from heterogeneous firms and substantial intra-industry reallocations take place, i.e. high productivity firms squeeze out low productivity firms. Previous tax-tool comparisons have not included these central forces of industry structure. This paper examines a...... general equilibrium monopolistic competition model with heterogeneous firms and intra-industry reallocations. We show that the welfare superiority of ad valorem over unit taxes under imperfect competition is not only preserved but amplified. The additional difference between the tools arises because unit...... taxes distort relative prices, which in turn reduces average industry productivity through reallocations (the survival and increased market share of lower productivity firms). Importantly, numerical solutions of the model reveal that the relative welfare loss from using the unit tax increases...
MUSICAL ARRANGEMENT OF MEDIA ADS
Directory of Open Access Journals (Sweden)
Chernyshov Alexander V.
2015-01-01
Full Text Available The music-compositional principles of commercial and political advertising and also the self-promotion of electronic media (radio, television, Internet are considered in this mediatext: from the elementary beeps, symbolic functions, emblems/logos and musical brands to the sound engineering technology to underscore the product's name and the complex synthesis between music and intra movements and color-light design of frames. Simultaneously examines, how the musical arrangement of ethereal advertising is involved in creation the emotional drama or bravado which reach the level of explicit or associative counterpoint 'music with the advertised object or subject' and which extend to expression of cultural image of all the broadcast channel. The article explores the works of the next genres like infomercial, teleshopping, film-ad, and autonomous commercials that have been produced in European countries or USA.
Increased hippocampal excitability in the 3xTgAD mouse model for Alzheimer's disease in vivo.
Directory of Open Access Journals (Sweden)
Katherine E Davis
Full Text Available Mouse Alzheimer's disease (AD models develop age- and region-specific pathology throughout the hippocampal formation. One recently established pathological correlate is an increase in hippocampal excitability in vivo. Hippocampal pathology also produces episodic memory decline in human AD and we have shown a similar episodic deficit in 3xTg AD model mice aged 3-6 months. Here, we tested whether hippocampal synaptic dysfunction accompanies this cognitive deficit by probing dorsal CA1 and DG synaptic responses in anaesthetized, 4-6 month-old 3xTgAD mice. As our previous reports highlighted a decline in episodic performance in aged control mice, we included aged cohorts for comparison. CA1 and DG responses to low-frequency perforant path stimulation were comparable between 3xTgAD and controls at both age ranges. As expected, DG recordings in controls showed paired-pulse depression; however, paired-pulse facilitation was observed in DG and CA1 of young and old 3xTgAD mice. During stimulus trains both short-latency (presumably monosynaptic: 'direct' and long-latency (presumably polysynaptic: 're-entrant' responses were observed. Facilitation of direct responses was modest in 3xTgAD animals. However, re-entrant responses in DG and CA1 of young 3xTgAD mice developed earlier in the stimulus train and with larger amplitude when compared to controls. Old mice showed less DG paired-pulse depression and no evidence for re-entrance. In summary, DG and CA1 responses to low-frequency stimulation in all groups were comparable, suggesting no loss of synaptic connectivity in 3xTgAD mice. However, higher-frequency activation revealed complex change in synaptic excitability in DG and CA1 of 3xTgAD mice. In particular, short-term plasticity in DG and CA1 was facilitated in 3xTgAD mice, most evidently in younger animals. In addition, re-entrance was facilitated in young 3xTgAD mice. Overall, these data suggest that the episodic-like memory deficit in 3xTgAD mice
Blomeyer, Christoph A; Bazil, Jason N; Stowe, David F; Dash, Ranjan K; Camara, Amadou K S
2016-06-01
The manner in which mitochondria take up and store Ca(2+) remains highly debated. Recent experimental and computational evidence has suggested the presence of at least two modes of Ca(2+) uptake and a complex Ca(2+) sequestration mechanism in mitochondria. But how Mg(2+) regulates these different modes of Ca(2+) uptake as well as mitochondrial Ca(2+) sequestration is not known. In this study, we investigated two different ways by which mitochondria take up and sequester Ca(2+) by using two different protocols. Isolated guinea pig cardiac mitochondria were exposed to varying concentrations of CaCl2 in the presence or absence of MgCl2. In the first protocol, A, CaCl2 was added to the respiration buffer containing isolated mitochondria, whereas in the second protocol, B, mitochondria were added to the respiration buffer with CaCl2 already present. Protocol A resulted first in a fast transitory uptake followed by a slow gradual uptake. In contrast, protocol B only revealed a slow and gradual Ca(2+) uptake, which was approximately 40 % of the slow uptake rate observed in protocol A. These two types of Ca(2+) uptake modes were differentially modulated by extra-matrix Mg(2+). That is, Mg(2+) markedly inhibited the slow mode of Ca(2+) uptake in both protocols in a concentration-dependent manner, but not the fast mode of uptake exhibited in protocol A. Mg(2+) also inhibited Na(+)-dependent Ca(2+) extrusion. The general Ca(2+) binding properties of the mitochondrial Ca(2+) sequestration system were reaffirmed and shown to be independent of the mode of Ca(2+) uptake, i.e. through the fast or slow mode of uptake. In addition, extra-matrix Mg(2+) hindered Ca(2+) sequestration. Our results indicate that mitochondria exhibit different modes of Ca(2+) uptake depending on the nature of exposure to extra-matrix Ca(2+), which are differentially sensitive to Mg(2+). The implications of these findings in cardiomyocytes are discussed.
Thermodynamic and classical instability of AdS black holes in fourth-order gravity
International Nuclear Information System (INIS)
We study thermodynamic and classical instability of AdS black holes in fourth-order gravity. These include the BTZ black hole in new massive gravity, Schwarzschild-AdS black hole, and higher-dimensional AdS black holes in fourth-order gravity. All thermodynamic quantities which are computed using the Abbot-Deser-Tekin method are used to study thermodynamic instability of AdS black holes. On the other hand, we investigate the s-mode Gregory-Laflamme instability of the massive graviton propagating around the AdS black holes. We establish the connection between the thermodynamic instability and the GL instability of AdS black holes in fourth-order gravity. This shows that the Gubser-Mitra conjecture holds for AdS black holes found from fourth-order gravity
Which AdS3 configurations contribute to the SCFT2 elliptic genus?
Murthy, S.V.; Nawata, S.
2011-01-01
According to the AdS=CFT duality, the superconformal index of a superconformal eld theory should have an AdS interpretation as a Euclidean functional integral with periodic boundary conditions on the fermions. Unlike the thermal case, the Euclidean continuation of the supersymmetric AdS black hole d
Armenta, Almudena; Guerrero, Teresa
2012-01-01
Esta publicación se realiza con motivo de la exposición titulada BOTANyCA celebrada en el Real Jardín Botánico de Madrid del 10 al 21 de octubre de 2012. Dicha exposición fue llevada a cabo por el Grupo de Investigación, Arte, Ciencia y Naturaleza de la Universidad Complutense de Madrid en colaboración con el Real Jardín Botánico. Comisariado de la exposición: Almudena Armenta y Teresa Guerrero. Coordinación técnica: Esther García Guillén y Marga Juárez Canga. Artistas participantes: Almudena...
c-a from the N=1 superconformal index
Ardehali, Arash Arabi; Szepietowski, Phillip
2014-01-01
We present a prescription for obtaining the difference of the central charges, c-a, of a four dimensional superconformal quantum field theory from its single-trace index. The formula is derived from a one-loop holographic computation, but is expected to be valid independent of holography. We demonstrate the prescription with several holographic and non-holographic examples. As an application of our formula, we show the AdS/CFT matching of c-a for arbitrary toric quiver CFTs without adjoint matter that are dual to smooth Sasaki-Einstein 5-manifolds.
Penedones, Joao
2016-01-01
We introduce the AdS/CFT correspondence as a natural extension of QFT in a fixed AdS background. We start by reviewing some general concepts of CFT, including the embedding space formalism. We then consider QFT in a fixed AdS background and show that one can define boundary operators that enjoy very similar properties as in a CFT, except for the lack of a stress tensor. Including a dynamical metric in AdS generates a boundary stress tensor and completes the CFT axioms. We also discuss some applications of the bulk geometric intuition to strongly coupled QFT. Finally, we end with a review of the main properties of Mellin amplitudes for CFT correlation functions and their uses in the context of AdS/CFT.
Recurring Anomaly Detection System (ReADS)
National Aeronautics and Space Administration — Overview: ReADS can analyze text reports, such as aviation reports and problem or maintenance records. ReADS uses text clustering algorithms to group loosely...
Material Developing for ADS Beam Window
Institute of Scientific and Technical Information of China (English)
XUYong-li; XUYuan-chao; LIHua-qing; NINGGuang-sheng; WANFa-rong; ZHAOFei
2003-01-01
The irradiation damage and the chemical interaction with the coolant for the ADS target and the structure materials are the key issues in ADS engineering. The developing of the materials that are irradiation and corrosion resistance is the important topic in ADS program in many countries. In this case,a topic of the material developing for the beam window has been proposed in our ADS program.
Condom ads promote illicit sex.
Kippley, J F
1994-01-01
Written in 1987, this opinion was republished in the wake of US President Bill Clinton's AIDS prevention media campaign promoting condom use which began January 1994, targeted at young adults aged 18-25. The author staunchly opposes condom use even though he admits that people do not consider abstinence from sex to be a serious option for the prevention of HIV/STD infection. He believes that there is no moral use of sex with a condom and that condoms have always been a sign of immorality, be it prostitution, adultery, fornication, or marital contraception. Likewise, the author laments the success enjoyed by Planned Parenthood in achieving the social acceptance of marital contraception and sex outside of marriage. The complete social acceptance of homosexual activity, however, remains to be achieved. Magazines, newspapers, and television receive income in exchange for publishing or airing advertisements. Finding offensive advertisements which promote the use of condoms against HIV infection, the author recommends writing letters of complaint to the responsible media sources. If the television stations or publications in question continue to advertise condoms to the public, stop watching them or end one's subscriptions to the particular printed media. Such action taken collectively among many individuals will reduce product sales and income, and potentially sway corporate policy against condom ads. PMID:12345946
Directory of Open Access Journals (Sweden)
Manasvi Kalra,
2016-02-01
Full Text Available The apps consist of advertisements to promote their products. Not all of them are appropriate to resume. Therefore various algorithms have been used in order to block those apps from existence but none of them is completely successful. In our app we are using an antivirus which can by default block those spy apps and remove them from the web page. The algorithm which has been used makes use of various ant viruses in the background which detect irrelevant and intimate apps and then our algorithm will demolish them. Certain apps are non-trustworthy where one click can spy all the mobile data. They block those apps and works on security. We are working on secure ads for mobile apps. It can also work as a basic antivirus where it detects the viruses like malwares in any of your installed apps or downloads. It will create a popup of discarding or keeping it. Mobile applications can be downloaded from anywhere like amazon, googleplay, apps store etc. There is no rigorous verification of an application when it is uploaded to the market. One can easily develop a malicious application and upload it to the app market. The user itself is responsible for accepting the risk of an app available from secondary markets. Therefore, we have decided to develop this app to make the market more secure and bounded. In future, It will take the mobile market while consuming minimal additional resources and preserving user privacy.
Symmetry Breaking, Central Charges and the AdS_2/CFT_1 Correspondence
Cadoni, Mariano; Mignemi, Salvatore
2000-01-01
When two-dimensional Anti-de Sitter space (AdS_2) is endowed with a non-constant dilaton the origin of the central charge in the Virasoro algebra generating the asymptotic symmetries of AdS_2 can be traced back to the breaking of the SL(2,R) isometry group of AdS_2. We use this fact to clarify some controversial results appeared in the literature about the value of the central charge in these models.
Accessing the nuclear symmetry energy in Ca+Ca collisions
Directory of Open Access Journals (Sweden)
Chbihi A.
2012-07-01
Full Text Available The status of the analysis of the INDRA-VAMOS experiement performed at GANIL, using the reactions 40,48Ca+40,48Ca reactions at 35AMeV, are presented. Isotopic distributions of fragments produced in multifragmentation events provide information on the importance of the surface term contribution in the symmetry energy by comparison to AMD predictions.
Reactivity monitoring in ADS systems
International Nuclear Information System (INIS)
Monitoring reactivity in an ADS should be performed on-line with a simple, accurate and robust technique. Within the range of experimental reactor techniques, no single technique can be selected which meet these requirements. Therefore a combination of different techniques has to be chosen in a way that various off-line techniques serve as a calibration for the on-line measurement technique. As an on-line measurement technique, the current/flux reactivity indicator is the most simple and robust solution. It is based on the fact that in a subcritical multiplying medium with a driving source the flux level is proportional to the driving source intensity, hence the beam current, and the reactivity level. However, since the proportionality constant depends on a number of core dependent parameters and detector characteristics, this current-to-flux indicator has to be calibrated on a regular basis. For this calibration, one could benefit from the occurrence of accelerator beam trips to determine the reactivity level in dollars by means of a prompt jump analysis of the flux level change. Hence, the prompt jump reactivity indicator could act as a first calibration tool of the current-to-flux indicator. Since the prompt jump indicator still relies on the value for the effective delayed neutron fraction to determine reactivity level, complementary techniques have to be used to obtain a more accurate determination of the reactivity. Techniques based on reactor noise methods such as RAPJA technique which is combination of the Rossi-alpha method and Prompt jump analysis can be used in this respect. In the future the bi-spectral ratio from the Cf - source driven noise analysis could be used for this purpose. (author)
Historical Literature in the ADS
Eichhorn, G.; Kurtz, M. J.; Accomazzi, A.; Grant, C. S.
1997-12-01
The Astrophysics Data System at http://adswww.harvard.edu is in the process of scanning the historical astronomical literature and making it available through the World Wide Web. We have scanned several volumes from the early 1800's of the "Astronomische Nachrichten", and the "Monthly Notices of the Royal Astronomical Society", the two oldest astronomical journals. We also have several of the early volumes of the "Astrophysical Journal" and the "Astronomical Journal" available. For all the journals that we cover, we have scanned volume 1. These early volumes can be accessed on a page-by-page basis. We plan to continue to scan this historical literature and complete these journals within the next year. We are also collaborating with a preservation project at Harvard University. This project will microfilm selected parts of astronomical Observatory reports. We plan to scan these microfilms to produce electronic images of these reports and put them on-line in the ADS. We hope to eventually cover most of the astronomical literature. In order to organize the scanned pages into articles, we need tables of contents (ToC). The early issues of the journals did not have printed ToC pages, so this needs to be done by hand. We do not have the financial resources to build these ToCs. We are looking for collaborators who would be willing to work with us in building these ToCs for the older journals and observatory reports. If you are interested in such a project, please contact the first author at gei@cfa.harvard.edu.
Light-cone AdS/CFT-adapted approach to AdS fields/currents, shadows, and conformal fields
Metsaev, R R
2015-01-01
Light-cone gauge formulation of fields in AdS space and conformal field theory in flat space adapted for the study of AdS/CFT correspondence is developed. Arbitrary spin mixed-symmetry fields in AdS space and arbitrary spin mixed-symmetry currents, shadows, and conformal fields in flat space are considered on an equal footing. For the massless and massive fields in AdS and the conformal fields in flat space, simple light-cone gauge actions leading to decoupled equations of motion are found. For the currents and shadows, simple expressions for all 2-point functions are also found. We demonstrate that representation of conformal algebra generators on space of currents, shadows, and conformal fields can be built in terms of spin operators entering the light-cone gauge formulation of AdS fields. This considerably simplifies the study of AdS/CFT correspondence. Light-cone gauge actions for totally symmetric arbitrary spin long conformal fields in flat space are presented. We apply our approach to the study of tota...
Ca2+ transport by mitochondria from L1210 mouse ascites tumor cells.
Reynafarje, B; Lehninger, A L
1973-06-01
Mitochondria isolated from the ascites form of L1210 mouse leukemia cells readily accumulate Ca(2+) from the suspending medium and eject H(+) during oxidation of succinate in the presence of phosphate and Mg(2+), with normal stoichiometry between Ca(2+) uptake and electron transport. Ca(2+) loads up to 1600 ng-atoms per mg of protein are attained. As is the case in mitochondria from normal tissues, Ca(2+) uptake takes precedence over oxidative phosphorylation. However, Ca(2+) transport by the L-1210 mitochondria is unusual in other respects, which may possibly have general significance in tumor cells. The apparent affinity of the L1210 mitochondria for Ca(2+) in stimulation of oxygen uptake is about 3-fold greater than in normal liver mitochondria; moreover, the maximal rate of Ca(2+) transport is also considerably higher. Furthermore, when Ca(2+) pulses are added to L1210 mitochondria in the absence of phosphate or other permeant anions, much larger amounts of Ca(2+) are bound and H(+) ejected per atom of oxygen consumed than in the presence of phosphate; up to 7 Ca(2+) ions are bound per pair of electrons passing each energy-conserving site of the electron-transport chain. Such "superstoichiometry" of Ca(2+) uptake can be accounted for by two distinct types of respiration-dependent interaction of Ca(2+) with the L1210 mitochondria. One is the stimulation of oxygen consumption, which is achieved by relatively low concentrations of Ca(2+) (K(m) congruent with 8 muM) and is accompanied by binding of Ca(2+) up to 40 ng-atoms per mg of protein. The second process, also dependent on electron transport, is the binding of further Ca(2+) from the medium in exchange with previously stored membrane-bound protons, in which the affinity for Ca(2+) is much lower (K(m) congruent with 120 muM).
Protein domain organisation: adding order
Directory of Open Access Journals (Sweden)
Kummerfeld Sarah K
2009-01-01
Full Text Available Abstract Background Domains are the building blocks of proteins. During evolution, they have been duplicated, fused and recombined, to produce proteins with novel structures and functions. Structural and genome-scale studies have shown that pairs or groups of domains observed together in a protein are almost always found in only one N to C terminal order and are the result of a single recombination event that has been propagated by duplication of the multi-domain unit. Previous studies of domain organisation have used graph theory to represent the co-occurrence of domains within proteins. We build on this approach by adding directionality to the graphs and connecting nodes based on their relative order in the protein. Most of the time, the linear order of domains is conserved. However, using the directed graph representation we have identified non-linear features of domain organization that are over-represented in genomes. Recognising these patterns and unravelling how they have arisen may allow us to understand the functional relationships between domains and understand how the protein repertoire has evolved. Results We identify groups of domains that are not linearly conserved, but instead have been shuffled during evolution so that they occur in multiple different orders. We consider 192 genomes across all three kingdoms of life and use domain and protein annotation to understand their functional significance. To identify these features and assess their statistical significance, we represent the linear order of domains in proteins as a directed graph and apply graph theoretical methods. We describe two higher-order patterns of domain organisation: clusters and bi-directionally associated domain pairs and explore their functional importance and phylogenetic conservation. Conclusion Taking into account the order of domains, we have derived a novel picture of global protein organization. We found that all genomes have a higher than expected
Flat Currents of Green-Schwarz Superstring in AdS2 × S2 Background
Institute of Scientific and Technical Information of China (English)
无
2006-01-01
From the κ symmetric action of ⅡB string in AdS2 × S2 background given by Zhou, we derive the equations of motion. By using the twisted dual transformation which was introduced by Hou, we construct the flat currents, conserving non-local charge with one free parameter, for the superstring in AdS2 × S2.
Effects of ad placement and type on consumer responses to podcast ads.
Ritter, Eric A; Cho, Chang-Hoan
2009-10-01
The purpose of this study was to understand the effects of podcast ad placement and podcast ad type on consumers' perceived intrusiveness, perceived irritation, attitude toward the ad, and ad avoidance. Our 2 x 2 (traditional ad vs. sponsorship by beginning vs. middle) experimental study found that sponsorships generated better consumer responses than did traditional ads and that podcast ads placed at the beginning of audio podcasts yielded better consumer responses than those placed in the middle. Implications for marketers and advertisers are discussed. PMID:19817565
From the generalized uncertainty relations on fuzzy AdS2 to the Poincare geometry
International Nuclear Information System (INIS)
The positive and discrete unitary irreps of SU(1,1) are used to construct fuzzy (Euclidean) AdS2. Two different types of uncertainty relation involving the Weyl-Heisenberg and a weaker type are studied. It is shown that there are no generalized coherent states which simultaneously minimize the Weyl-Heisenberg uncertainty relations among three non-commuting embedding coordinates of the fuzzy AdS2. However, generalized squeezed states that simultaneously satisfy the three weaker uncertainty relations do exist, and reproduce some properties of the classical AdS2. Up to a common scaling factor in terms of the irrep label, the expectation values of the non-commuting coordinates over such states are described in the same manner as the classical AdS2, in terms of the Poincare coordinates. The expectation values on the fuzzy AdS2 tend to their corresponding values in the commutative limit. (orig.)
Directory of Open Access Journals (Sweden)
Sara Sanz-Blasco
Full Text Available Dysregulation of intracellular Ca(2+ homeostasis may underlie amyloid beta peptide (Abeta toxicity in Alzheimer's Disease (AD but the mechanism is unknown. In search for this mechanism we found that Abeta(1-42 oligomers, the assembly state correlating best with cognitive decline in AD, but not Abeta fibrils, induce a massive entry of Ca(2+ in neurons and promote mitochondrial Ca(2+ overload as shown by bioluminescence imaging of targeted aequorin in individual neurons. Abeta oligomers induce also mitochondrial permeability transition, cytochrome c release, apoptosis and cell death. Mitochondrial depolarization prevents mitochondrial Ca(2+ overload, cytochrome c release and cell death. In addition, we found that a series of non-steroidal anti-inflammatory drugs (NSAIDs including salicylate, sulindac sulfide, indomethacin, ibuprofen and R-flurbiprofen depolarize mitochondria and inhibit mitochondrial Ca(2+ overload, cytochrome c release and cell death induced by Abeta oligomers. Our results indicate that i mitochondrial Ca(2+ overload underlies the neurotoxicity induced by Abeta oligomers and ii inhibition of mitochondrial Ca(2+ overload provides a novel mechanism of neuroprotection by NSAIDs against Abeta oligomers and AD.
AGRICULTURAL VALUE ADDED: PROSPECTS FOR NORTH DAKOTA
Lambert, David K.; Lim, Siew Hoon; Tweeten, Kathleen M.; Leistritz, F. Larry; Wilson, William W.; McKee, Gregory J.; Nganje, William E.; DeVuyst, Cheryl Sinn; Saxowsky, David M.
2006-01-01
Introduction: This report provides an overview of the important factors affecting investments in agricultural value-added ventures. The introductory section outlines current research on factors important in the location of economic activity. Research applied to specific agricultural value-added ventures, such as food manufacturing and livestock feeding and finishing operations, are discussed. A listing of resources available to entrepreneurs considering value-added investments concludes the i...
Zhang, Jia-Lin; Cai, Rong-Gen; Yu, Hongwei
2014-01-01
We study the thermodynamics and thermodynamic geometry of a five-dimensional Schwarzschild AdS black hole in AdS 5 × S 5 spacetime by treating the cosmological constant as the number of colors in the boundary gauge theory and its conjugate quantity as the associated chemical potential. It is found that the chemical potential is always negative in the stable branch of black hole thermodynamics and it has a chance to be positive, but appears in the unstable branch. We calculate the scalar curva...
Ad-Coop Positioning System (ACPS)
DEFF Research Database (Denmark)
Frattasi, Simone; Monti, Marco
2008-01-01
In this paper, we propose an innovative solution for positioning determination in 4G wireless networks by introducing the Ad-Coop Positioning System (ACPS). The ACPS is supported by a hybrid cellular ad-hoc architecture, where the cellular network has a centralized control over the ad-hoc...... connections among pairs of mobiles. Specifically, peer-to-peer (P2P) communications are exploited in a mesh fashion within cellular-established clusters for cooperation-aided localization purposes (from that, the word ad-coop is derived). The major contribution of this work is the design of the data fusion...... to conventional hybrid positioning techniques in cellular networks....
Changes of inclusion, texture and magnetic property of non-oriented Si steel treated by Ca alloy
Lv, X.; Zhang, F.; Chen, X.
2015-04-01
Based on the industrial production of non-oriented Si steel, Ca treatment by Ca alloy adding during the RH refining process was studied. The changes of inclusion, crystal texture and microstructure, and its effect on magnetic properties of final steel sheets were analyzed. The results showed that, in present work, Ca treatment can improve the texture proportion of {110} and {111} significantly, and the formation of MnS and AlN inclusions were restrained. Meanwhile, the recrystallization effects of hot rolled strip get bad and the fiber structure enhanced obviously. The grain size of finished steel sheets increased as the increase of Ca alloy adding amount quickly, and then decreased. Compared with the non-Ca treatment charge, the numbers of inclusions whose size below 1.0μm will decrease by 68.06%, 87.50% and 94.94%, the texture proportion of {110} and {111} was 30.3%, 39.1%, 17.6% and 2.8%, 5.5%, 20.6%, while the correspondent Ca alloy adding amount is 0.67 kg/t steel, 1.00 kg/t steel and 1.67 kg/t steel, respectively. In addition, the core loss gradually decreases to a stable level as the increasing of Ca added, and the magnetic induction decreases quickly after slow increasing, respectively. The optimal Ca treatment mode depends on the chemical compositions of steel grades.
On shape dependence of holographic entanglement entropy in AdS4/CFT3
Fonda, Piermarco; Tonni, Erik
2015-01-01
We study the finite term of the holographic entanglement entropy of finite domains with smooth shapes and for four dimensional gravitational backgrounds. Analytic expressions depending on the unit vectors normal to the minimal area surface are obtained for both stationary and time dependent spacetimes. The special cases of AdS4, asymptotically AdS4 black holes, domain wall geometries and Vaidya-AdS backgrounds have been analysed explicitly. When the bulk spacetime is AdS4, the finite term is the Willmore energy of the minimal area surface viewed as a submanifold of the three dimensional flat Euclidean space. For the static spacetimes, some numerical checks involving spatial regions delimited by ellipses and non convex domains have been performed. In the case of AdS4, the infinite wedge has been also considered, recovering the known analytic formula for the coefficient of the logarithmic divergence.
Half BPS states in AdS5 x Yp,q
International Nuclear Information System (INIS)
We study a class of solutions of IIB supergravity which are asymptotically AdS5 x Yp,q. They have an R x SO(4) x SU(2) x U(1) isometry and preserve half of the 8 supercharges of the background geometry. They are described by a set of second order differential equations that we have found and analysed in a previous paper, where we studied 1/8 BPS states in the maximally supersymmetric AdS5 x S5 background. These geometries correspond to certain chiral primary operators of the N = 1 superconformal quiver theories, dual to IIB theory on AdS5 x Yp,q. We also show how to recover the AdS5 x Yp,q backgrounds by suitably doubling the number of preserved supersymmetries. We then solve the differential equations perturbatively in a large AdS5 radius expansion, imposing asymptotic AdS5 x Yp,q boundary conditions. We compute the global baryonic and mesonic charges, including the R-charge. As for the computation of the mass, i.e. the conformal dimension Δ of the dual field theory operators, which is notoriously subtle in asymptotically AdS backgrounds, we adopt the general formalism due to Wald and collaborators, which gives a finite result, and verify the relation Δ = 3R/2, demanded by the N = 1 superconformal algebra
National Oceanic and Atmospheric Administration, Department of Commerce — Sonoma County Vegetation Mapping and LiDAR Consortium retained WSI to provide lidar and Orthophoto data and derived products in Sonoma County, CA. A classified LAS...
CaPTC hosts the 'Biennial Science of Global Prostate Cancer Disparities in Black Men' conference to address the growing global public health problem of prostate cancer among Black men in industrialized and developing countries.
International Nuclear Information System (INIS)
CaWave User's Guide explains how to use the CaWave functions which were specifically written in PV-WAVE command language and C language for EPICS users. CaWave consists of a special set of external channel access functions which provides the PV-WAVE users with easy and flexible access of channel information across the IOC networks. It also provides a complete set of process variable event monitoring functions. This document also gives examples how a PV-WAVE user can interface to channel access devices. It is assumed that the user is already familiar with using PV-WAVE. Few simple example modules of using PV-WAVE command language with CaWave functions are also given in this document
New pyrometallurgical process of EAF dust treatment with CaO addition
Chairaksa-Fujimoto, Romchat; Inoue, Yosuke; Umeda, Naoyoshi; Itoh, Satoshi; Nagasaka, Tetsuya
2015-08-01
The non-carbothermic zinc pyrometallurgical processing of electric arc furnace (EAF) dust was investigated on a laboratory scale. The main objective of this process was to convert highly stable zinc ferrite (ZnFe2O4), which accounts for more than half of total zinc in the EAF dust, into ZnO and Ca2Fe2O5 by CaO addition. The EAF dust was mixed with CaO powder in various ratios, pressed into pellets, and heated in a muffle furnace in air at temperatures ranging from 700 to 1100°C for a predetermined holding time. All ZnFe2O4 was transformed into ZnO and Ca2Fe2O5 at a minimum temperature of 900°C within 1 h when sufficient CaO to achieve a Ca/Fe molar ratio of 1.1 was added. However, at higher temperatures, excess CaO beyond the stoichiometric ratio was required because it was consumed by reactions leading to the formation of compounds other than ZnFe2O4. The evaporation of halides and heavy metals in the EAF dust was also studied. These components could be preferentially volatilized into the gas phase at 1100°C when CaO was added.
New pyrometallurgical process of EAF dust treatment with CaO addition
Institute of Scientific and Technical Information of China (English)
Romchat Chairaksa-Fujimoto; Yosuke Inoue; Naoyoshi Umeda; Satoshi Itoh; Tetsuya Nagasaka
2015-01-01
The non-carbothermic zinc pyrometallurgical processing of electric arc furnace (EAF) dust was investigated on a laboratory scale. The main objective of this process was to convert highly stable zinc ferrite (ZnFe2O4), which accounts for more than half of total zinc in the EAF dust, into ZnO and Ca2Fe2O5 by CaO addition. The EAF dust was mixed with CaO powder in various ratios, pressed into pellets, and heated in a muffle furnace in air at temperatures ranging from 700 to 1100°C for a predetermined holding time. All ZnFe2O4 was transformed into ZnO and Ca2Fe2O5 at a minimum temperature of 900°C within 1 h when sufficient CaO to achieve a Ca/Fe molar ratio of 1.1 was added. However, at higher temperatures, excess CaO beyond the stoichiometric ratio was required because it was consumed by reactions leading to the formation of compounds other than ZnFe2O4. The evaporation of halides and heavy metals in the EAF dust was also studied. These components could be pref-erentially volatilized into the gas phase at 1100°C when CaO was added.
CA 242, a new tumour marker for pancreatic cancer: a comparison with CA 19-9, CA 50 and CEA.
Haglund, C.; Lundin, J; Kuusela, P.; Roberts, P. J.
1994-01-01
The serum expression of a novel tumour marker, CA 242, defined by monoclonal antibody C 242, was studied in 179 patients with pancreatic cancer. The results were compared with CA 19-9, CA 50 and CEA. CA 242 is a carbohydrate closely related, but not identical, to CA 19-9 and CA 50. The overall sensitivity of the CA 242 assay was 74%: 55% in stage I, 83% in stage II-III and 78% in stage IV disease. The specificity calculated from 112 patients with benign diseases was 91%. CA 19-9 had a higher ...
Using Wikipedia categories for ad hoc search
R. Kaptein; M. Koolen; J. Kamps
2009-01-01
In this paper we explore the use of category information for ad hoc retrieval in Wikipedia. We show that techniques for entity ranking exploiting this category information can also be applied to ad hoc topics and lead to significant improvements. Automatically assigned target categories are good sur
Queueing models for mobile ad hoc networks
Haan, de Roland
2009-01-01
This thesis presents models for the performance analysis of a recent communication paradigm: mobile ad hoc networking. The objective of mobile ad hoc networking is to provide wireless connectivity between stations in a highly dynamic environment. These dynamics are driven by the mobility of stations
Geometric finiteness, holography and quasinormal modes for the warped AdS3 black hole
International Nuclear Information System (INIS)
We show that there exists a precise kinematical notion of holography for the Euclidean warped AdS3 black hole. This follows from the fact that the Euclidean warped AdS3 black hole spacetime is a geometrically finite hyperbolic manifold. For such manifolds a theorem of Sullivan provides a one-to-one correspondence between the hyperbolic structure in the bulk and the conformal structure of its boundary. Using this theorem we obtain the holographic quasinormal modes for the warped AdS3 black hole.
Google Advertising Tools Cashing in with AdSense and AdWords
Davis, Harold
2010-01-01
With this book, you'll learn how to take full advantage of Google AdWords and AdSense, the sophisticated online advertising tools used by thousands of large and small businesses. This new edition provides a substantially updated guide to advertising on the Web, including how it works in general, and how Google's advertising programs in particular help you make money. You'll find everything you need to work with AdWords, which lets you generate text ads to accompany specific search term results, and AdSense, which automatically delivers precisely targeted text and image ads to your website.
An improved AFS phase for AdS3 string integrability
Abbott, Michael C
2015-01-01
We propose a number of modifications to the classical term in the dressing phase for integrable strings in AdS3 x S3 x S3 x S1, and check these against existing perturbative calculations, crossing symmetry, and the semiclassical limit of the Bethe equations. The principal change is that the phase for different masses should start with a term Q_1 Q_2, like the one-loop AdS3 dressing phase, rather than Q_2 Q_3 as for the original AdS5 AFS phase.
Mazhari, N S; Bahamonde, Sebastian; Faizal, Mir; Myrzakulov, Ratbay
2016-01-01
The holographic complexity and fidelity susceptibility have been defined as new quantities dual to different volumes in AdS. In this paper, we will use these new proposals to calculate both of these quantities for a variety of interesting deformations of AdS. We obtain the holographic complexity and fidelity susceptibility for an AdS black hole, Janus solution and a solution with cylindrically symmetry, an inhomogeneous background and a hyperscaling violating background. It is observed that the holographic complexity depends on the size of the subsystem for all these solutions and the fidelity susceptibility does not any such dependence.
On circular strings in (AdS3 × S 3)ϰ
Banerjee, Aritra; Panigrahi, Kamal L.
2016-09-01
The so called one-parameter (often called ϰ) deformed AdS string sigma models have attracted a lot of attention lately in the study of integrability in string theory. We construct various circular string solutions in the (AdS3 × S 3) ϰ background and describe the characteristics of such solutions qualitatively. We study the Bohr-Sommerfeld like quantization for these string states to characterise the motion. Further we find a `long' string limit of such circular strings in the ϰ-deformed AdS3 and find a novel dependence of the oscillation number on the energy in the next to leading order expansion.
On circular strings in $(AdS_3 \\times S^3)_{\\varkappa}$
Banerjee, Aritra
2016-01-01
The so called one-parameter (often called $\\varkappa$) deformed $AdS$ string sigma models have attracted a lot of attention lately in the study of integrability in string theory. We construct various circular string solutions in the $(AdS_3 \\times S^3)_{\\varkappa}$ background and describe the characteristics of such solutions qualitatively. We study the Bohr-Sommerfeld like quantization for these string states to characterise the motion. Further we find a `long' string limit of such circular strings in the $\\varkappa$-deformed $AdS_3$ and find a novel dependence of the oscillation number on the energy in the next to leading order expansion.
The concept of added value of FM
DEFF Research Database (Denmark)
Jensen, Per Anker; van der Voordt, Theo; Coenen, Christian;
2012-01-01
Purpose: This chapter presents research perspectives and theoretical reflections on the concept of added value of FM from a variety of academic fields. Methodology: A literature review of the most influential journals within the academic fields of Facilities Management (FM), Corporate Real Estate...... conceptualization of the concept of added value of FM is of utmost importance for further research into the added value of FM and well-considered, evidence- based Value Adding Management in practice. Research limitations: Due to limited time not all FM-related journals could be included in the literature review....... The included journals were analysed over a time period of ten years, with a focus on interesting topics and less on a thematic cross-paper analysis in-depth. Originality/value: Usually the concept of added value is discussed from a mono-disciplinary point of view. The different backgrounds of the authors add...
Ishii, Takaaki
2015-01-01
We study nonlinear dynamics of the flux tube between an external quark-antiquark pair in $\\mathcal{N}=4$ super Yang-Mills theory using the AdS/CFT duality. In the gravity side, the flux tube is realized by a fundamental string whose endpoints are attached to the AdS boundary. We perturb the endpoints in various ways and numerically compute the time evolution of the nonlinearly oscillating string. As a result, cusps can form on the string, accompanied by weak turbulence and power law behavior in the energy spectrum. When cusps traveling on the string reach the boundary, we observe the divergence of the force between the quark and antiquark. Minimal amplitude of the perturbation below which cusps do not form is also investigated. No cusp formation is found when the string moves in all four AdS space directions, and in this case an inverse energy cascade follows a direct cascade.
Energy Technology Data Exchange (ETDEWEB)
Freivogel, Ben; /Stanford U., Phys. Dept. /LBL, Berkeley; Hubeny, Veronika E.; /LBL, Berkeley /Durham U., Dept. of Math.; Maloney, Alexander; /Stanford U., Phys. Dept.; Myers, Rob; /Perimeter Inst. Theor. Phys. /Waterloo U.; Rangamani, Mukund; /LBL, Berkeley /Durham U., Dept. of Math.; Shenker, Stephen; /Stanford U., Phys. Dept.
2005-10-07
We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.We study the realization of inflation within the AdS/CFT correspondence. We assume the existence of a string landscape containing at least one stable AdS vacuum and a (nearby) metastable de Sitter state. Standard arguments imply that the bulk physics in the vicinity of the AdS minimum is described by a boundary CFT. We argue that large enough bubbles of the dS phase, including those able to inflate, are described by mixed states in the CFT. Inflating degrees of freedom are traced over and do not appear explicitly in the boundary description. They nevertheless leave a distinct imprint on the mixed state. Analytic continuation allows us, in principle, to recover a large amount of nonperturbatively defined information about the inflating regime. Our work also shows that no scattering process can create an inflating region, even by quantum tunneling, since a pure state can never evolve into a mixed state under unitary evolution.
Institute of Scientific and Technical Information of China (English)
YANG Mingbo; CHENG Liang; SHEN Jia; PAN Fusheng
2009-01-01
The effect of Ca addition on the as-cast microstructure and creep properties of Mg-5Zn-5Sn magnesium alloy was investigated. The results indicate that adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy can effectively refine the as-cast microstructure of the alloy, and the CaMgSn phase with high thermal stability is formed in the alloy. In addition, adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy can also improve the creep properties of the alloy. After adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy, the second creep rate of the alloy at 150℃ and 50 MPa for 100 h decreases from 4.67×10~(-8) to 1.43×10~(-8) s~(-1). The strengthening mechanism is mainly attributed to the microstructural refinement and the formation of CaMgSn phase.
González-Vega, J Caroline; Walk, Carrie L; Liu, Yanhong; Stein, Hans H
2014-01-01
An experiment was conducted to test the hypothesis that the standardised digestibility of Ca in calcium carbonate and Lithothamnium calcareum Ca is not different regardless of the level of dietary Ca, and that phytic acid affects the digestibility of Ca in these two ingredients to the same degree. The objectives were to determine where in the intestinal tract Ca absorption takes place and if there are measurable quantities of basal endogenous Ca fluxes in the stomach, small intestine or large intestine. Diets contained calcium carbonate or L. calcareum Ca as the sole source of Ca, 0% or 1% phytic acid and 0.4% or 0.8% Ca. A Ca-free diet was also formulated and used to measure endogenous fluxes and losses of Ca. Nine growing pigs (initial body weight 23.8 ± 1.3 kg) were cannulated in the duodenum and in the distal ileum, and faecal, ileal and duodenal samples were collected. Duodenal endogenous fluxes of Ca were greater (p interaction, p < 0.05). The standardised duodenal digestibility (SDD), standardised ileal digestibility (SID) and standardised total tract digestibility (STTD) of Ca were not different if calcium carbonate was the source of dietary Ca. However, the STTD of Ca in L. calcareum Ca was greater (p < 0.05) than the SID and SDD of Ca. The SDD, SID and STTD of Ca in calcium carbonate were greater (p < 0.05) than those of L. calcareum Ca. In conclusion, under the conditions of this experiment, standardised digestibility of Ca is not affected by the level of phytic acid, but may be affected by dietary Ca level depending on the Ca source. Calcium from calcium carbonate is mostly absorbed before the duodenum, but Ca from L. calcareum Ca is mostly absorbed in the jejunum and ileum. PMID:24646151
Decomposition Reaction of Mixed Rare Earth Concentrate and Roasted with CaO and NaCl
Institute of Scientific and Technical Information of China (English)
Wu Wenyuan; Hu Guangyong; Sun Shuchen; Chen Xudong; Tu Ganfeng
2004-01-01
The reaction of the mixed rare earth concentrate including monazite ( REPO4 ) and bastnaesite ( REFCO3 )decomposed by CaO and NaCl additives at the temperature range from 100 to 1000 ℃ was studied by means of XRD and TG-DTA.The results show that when CaO and NaCl are not added, only REFCO3 can be decomposed at the temperature of 377 ～ 450 ℃.The decomposition products include REOF, RE2O3 and CeO2.However, REFCO3 can not be decomposed.When CaO is added, the decomposition reactions occur at the temperature range from 660 to 750 ℃.CaO has three decomposition functions: ( 1 ) REPO4 can be decomposed by CaO and the decomposition products include RE2O3 and Ca3 (PO4)2; (2) CaO can decompose REOF, and the decomposition products are RE2O3 and CaF2; (3)CaO can decompose REPO4 with CaF2, and the decomposition products are RE2 O3, Ca5 F( PO4 )3.The decomposition ratio of the mixed rare earth concentrate increased obviously, when CaO and NaC1 were added.NaC1 can supply the liquid for the reaction, improve the mass transfer process and accelerate the reaction.At the same time, NaC1 participated in the reaction that REPO4 was decomposed by CaO.
Absorption of /sup 45/Ca during the immersion of the aerial organs of Salicornia stricta
Energy Technology Data Exchange (ETDEWEB)
Langlois, J.; Vilquin, A.
1971-04-01
Immersion of the aerial organs of Salicornia stricta in a nutrient solution with added radioactive /sup 45/Ca resulted in the accumulation of /sup 45/Ca in the aerial organs. There was no accumulation when the roots were immersed in the nutrient solution. Absorption of minerals by the stems and leaves of Salicornia during periodic submersions in the brackish water surrounding the plants, is therefore possible. 17 references, 1 figure, 1 table.
Study Added of Waste Chicken Egg Shell in Soils
Directory of Open Access Journals (Sweden)
Keng Wong Irwan Lie
2016-01-01
Full Text Available Soil is the foundation of structure or construction that will receive the load transfer through to foundation. If the soil has a carrying capacity of small and cannot withstand the load transfer can result in the failure of construction. If the soil has a carrying capacity of small ground it is necessary to stabilize or improve the soil so that an increase in the carrying capacity of the land so that it can be used for construction. One material is commonly used for soil stabilization with the addition of lime. Waste chicken egg shell is waste that is still rarely used, the results of research [1], states that composition egg shell broadly consists of water (1,6% and dry material (98,4%. The total dry ingredients are there, in shell eggs contained mineral elements (95,1% and protein (3,3%. Based on the existing mineral composition, then the egg shells are composed of crystalline CaCO3 (98,43%, MgCO3 (0,84% and Ca3(PO42 (0,75%. This research was done by adding powdered chicken egg shell waste in clay with a composition of 5%, 7,5%, 10% and 14% with physical properties test and soil compaction test.
A Grassmann Path From AdS$_3$ to Flat Space
Krishnan, Chethan; Roy, Shubho
2013-01-01
We show that interpreting the inverse AdS$_3$ radius $1/l$ as a Grassmann variable results in a formal map from gravity in AdS$_3$ to gravity in flat space. The underlying reason for this is the fact that $ISO(2,1)$ is the Inonu-Wigner contraction of $SO(2,2)$. We show how this works for the Chern-Simons actions, demonstrate how the general (Banados) solution in AdS$_3$ maps to the general flat space solution, and how the Killing vectors, charges and the Virasoro algebra in the Brown-Henneaux case map to the corresponding quantities in the BMS$_3$ case. Our results straightforwardly generalize to the higher spin case: the recently constructed flat space higher spin theories emerge automatically in this approach from their AdS counterparts. We conclude with a discussion of singularity resolution in the BMS gauge as an application.
Two gravitational shock waves on the AdS3 brane
International Nuclear Information System (INIS)
A gravitational shock wave is a solution to Einstein equations describing the gravitational field of a massless particle. We obtain such a geometry for a particle moving on a AdS3 brane embedded in a AdS4 bulk (the lower dimensional version of the ''locally localized gravity'' model of Karch and Randall). In order to do this, we use two different techniques. First, we solve directly Einstein equations sourced by a massless particle. Then we boost to the speed of light the AdS3 brane black hole solution of Emparan et al. while sending its mass parameter to zero. Surprisingly, we obtain two different results. We discuss the origin of these two different solutions both in the bulk and in the CFT picture. As a by-product, we derive the expression for the shock wave associated to a transversally accelerating particle in AdS4
Impaired cognition in depression and Alzheimer (AD: a gradient from depression to depression in AD
Directory of Open Access Journals (Sweden)
Narahyana Bom de Araujo
2014-09-01
Full Text Available Objective To assess cognition in major depressed (MD, Alzheimer's disease (AD, and depression in AD elderly. Method Subjects were evaluated by Mini Mental, Rey Auditory Verbal Learning Test, Rey Complex Figure, Digit Span, Similarities, Trail Making A/B, Verbal Fluency and Stroop. One-way ANOVA and multivariate models were used to compare the performance of each group on neuropsychological tests. Results We evaluated 212 subjects. Compared to MD, attention, working memory, processing speed and recall showed significantly better in controls. Controls showed significantly higher performance in all cognitive measures, except in attention compared to AD. Verbal fluency, memory, processing speed and abstract reasoning in MD was significantly higher compared to AD. AD was significantly better in general cognitive state than depression in AD. All other cognitive domains were similar. Conclusion A decreasing gradient in cognition appeared from the control to depression in AD, with MD and AD in an intermediate position.
On Critical Massive (Super)Gravity in adS3
Bergshoeff, Eric A; Rosseel, Jan; Sezgin, Ergin; Townsend, Paul K
2010-01-01
We review the status of three-dimensional "general massive gravity" (GMG) in its linearization about an anti-de Sitter (adS) vacuum, focusing on critical points in parameter space that yield generalizations of "chiral gravity". We then show how these results extend to N=1 super-GMG, expanded about a supersymmetric adS vacuum, and also to the most general `curvature-squared' N=1 supergravity model.
Ad Hoc Network Securing Policy%Ad hoc网络安全策略
Institute of Scientific and Technical Information of China (English)
刘志远; 张曼曼
2006-01-01
本文首先介绍了Ad hoc网络的产生、定义、特点和应用,然后在探讨Ad hoc网络的安全需求的基础上,着重分析了移动Ad hoc网络易于遭受的攻击,最后讨论并提出了Ad Hoc网络的一些安全策略.
On the gauge dependence of the AdS instability problem
Dimitrakopoulos, Fotios V; Pedraza, Juan F; Yang, I-Sheng
2016-01-01
Previous work on the AdS instability problem within the two-time framework (TTF) has found an "oscillating singularity" whose presence depends on the gauge choice. We give a physical interpretation of this singularity as a diverging redshift between the boundary and the center of AdS. This signals a genuine breakdown of the linearized gravity. One can also identify the diverging redshift through a back-reaction calculation purely in the boundary gauge, where the TTF result stays regular.
Ads/CFT correspondence and symmetry breaking
International Nuclear Information System (INIS)
We study, using the dual AdS description, the vacua of field theories where some of the gauge symmetry is broken by expectation values of scalar fields. In such vacua, operators built out of the scalar fields acquire expectation values, and we show how to calculate them from the behavior of perturbations to the AdS background near the boundary. Specific examples include the N = 4 SYM theory, and theories on D3-branes placed on orbifolds and conifolds. We also clarify some subtleties of the AdS/CFT correspondence that arise in this analysis. In particular, we explain how scalar fields in AdS space of sufficiently negative mass-squared can be associated with CFT operators of two possible dimensions. All dimensions are bounded from below by (d-2)/2; this is the unitarity bound for scalar operators in d-dimensional field theory. We further argue that the generating functional for correlators in the theory with one choice of operator dimension is a Legendre transform of the generating functional in the theory with the other choice
Study of ADS-B Data Evaluation
Institute of Scientific and Technical Information of China (English)
ZHANG Jun; LIU Wei; ZHU Yanbo
2011-01-01
In western China,the terrain and meteorological conditions are so complex that it is not suitable to construct new radar stations.Automatic dependent surveillance-broadcast(ADS-B) is a totally new surveillance method,so before practically applied and operated in China,abundant tests and evaluations are necessary to validate the performance of ADS-B and guarantee the operational security.During the flight tests,we collect the data of radar,ADS-B and high accuracy position and compare the performance of ADS-B with radar based on high accuracy position.To solve the asynchronous problem among radar data,ADS-B data and real-time kinematic(RTK) data caused by different update rates,this article proposes the technique of synchronizing multi-surveil- lance data by extrapolating from the data of low update rate to high update rate according to velocity and heading.Meanwhile,because radar data,ADS-B data and RTK data are expressed in different coordinates and cannot be compared each other,this article provides a method to unifying the coordinates of multi-surveillance data.By the analysis and evaluation,we can conclude that the performance of ADS-B is better than radar.
Half BPS states in AdS_5 x Y^{p,q}
Gava, Edi; Milanesi, Giuseppe; O'Loughlin, Martin
2008-01-01
We study a class of solutions of IIB Supergravity which are asymptotically AdS_5 x Y^{p,q}. They have an R x SO(4) x SU(2) x U(1) isometry and preserve half of the 8 supercharges of the background geometry. They are described by a set of second order differential equations that we have found and analysed in a previous paper, where we studied 1/8 BPS states in the maximally supersymmetric AdS_5 x S^5 background. These geometries correspond to certain chiral primary operators of the N=1 superconformal quiver theories, dual to IIB theory on AdS_5 x Y^{p,q}. We also show how to recover the AdS_5 x Y^{p,q} backgrounds by suitably doubling the number of preserved supersymmetries. We then solve the differential equations perturbatively in a large AdS_5 radius expansion, imposing asymptotic AdS_5 x Y^{p,q} boundary conditions. We compute the global baryonic and mesonic charges, including the R-charge. As for the computation of the mass, i.e. the conformal dimension D of the dual field theory operators, which is notor...
Service placement in ad hoc networks
Wittenburg, Georg
2012-01-01
Service provisioning in ad hoc networks is challenging given the difficulties of communicating over a wireless channel and the potential heterogeneity and mobility of the devices that form the network. Service placement is the process of selecting an optimal set of nodes to host the implementation of a service in light of a given service demand and network topology. The key advantage of active service placement in ad hoc networks is that it allows for the service configuration to be adapted continuously at run time. ""Service Placement in Ad Hoc Networks"" proposes the SPi service placement fr
Indian Academy of Sciences (India)
Jacinta S D’souza; Man Mohan Johri
2003-03-01
We have demonstrated the presence of a Ca2+-dependent/calmodulin-stimulated protein kinase (PK) in chloronema cells of the moss Funaria hygrometrica. The kinase, with a molecular mass of 70,000 daltons (PK70), was purified to homogeneity using ammonium sulphate fractionation, DEAE-cellulose chromatography, and calmodulin (CaM)-agarose affinity chromatography. The kinase activity was stimulated at a concentration of 50 M free Ca2+, and was further enhanced 3–5-fold with exogenously added 3–1000 nm moss calmodulin (CaM). Autophosphorylation was also stimulated with Ca2+ and CaM. Under in vitro conditions, PK70 phosphorylated preferentially lysine-rich substrates such as HIIIS and HVS. This PK shares epitopes with the maize Ca2+-dependent/calmodulin-stimulated PK (CCaMK) and also exhibits biochemical properties similar to the maize, lily, and tobacco CCaMK. We have characterized it as a moss CCaMK.
Tactical Ad hoc Network Clustering%战术Ad hoc网分群研究
Institute of Scientific and Technical Information of China (English)
徐长通; 刘行兵; 张聪品
2010-01-01
分级Ad hoc网结构与战术Ad hoc网结构相似,但存在本质差别,分级Ad hoc网群组的形成及群成员产生随机,而战术Ad hoc子网指挥员节点和成员固定.文中分析战术Ad hoc网的特点,定义了节点参数,进行了节点状态描述.通过群组的规划,提出了节点自定位部署算法.
String in AdS Black Hole: A Thermo Field Dynamic Approach
Cantcheff, M. Botta; Gadelha, Alexandre L.; Marchioro, Dafni F. Z.; Nedel, Daniel Luiz
2012-01-01
Based on Maldacena's description of an eternal AdS-black hole, we reassess the Thermo Field Dynamics (TFD) formalism in the context of the AdS/CFT correspondence. The model studied here involves the maximally extended AdS-Schwarschild solution and two (non-interacting) copies of the CFT associated to the global AdS spacetime, along with an extension of the string by imposing natural gluing conditions in the horizon. We show that the gluing conditions in the horizon define a string boundary st...
The Tetrahedron Zamolodchikov Algebra and the AdS5 x S5 S-matrix
Mitev, Vladimir; Tsuboi, Zengo
2012-01-01
The S-matrix of the AdS5 x S5 string theory is a tensor product of two centrally extended su(2|2) S-matrices, each of which is related to the R-matrix of the Hubbard model. The R-matrix of the Hubbard model was first found by Shastry, who ingeniously exploited the fact that, for zero coupling, the Hubbard model can be decomposed into two XX models. In this article, we review and clarify this construction from the AdS/CFT perspective and investigate the implications this has for the AdS5 x S5 S-matrix.
Heat kernels on cone of AdS2 and k-wound circular Wilson loop in AdS5 × S5 superstring
Bergamin, R.; Tseytlin, A. A.
2016-04-01
We compute the one-loop world-sheet correction to partition function of {{AdS}}5× {{{S}}}5 superstring that should be representing k-fundamental circular Wilson loop in planar limit. The 2d metric of the minimal surface ending on k-wound circle at the boundary is that of a cone of AdS2 with deficit 2π (1-k). We compute the determinants of 2d fluctuation operators by first constructing heat kernels of scalar and spinor Laplacians on the cone using the Sommerfeld formula. The final expression for the k-dependent part of the one-loop correction has simple integral representation but is different from earlier results.
Nastase, Horatiu
2007-01-01
These lectures present an introduction to AdS-CFT, and are intended both for begining and more advanced graduate students, which are familiar with quantum field theory and have a working knowledge of their basic methods. Familiarity with supersymmetry, general relativity and string theory is helpful, but not necessary, as the course intends to be as self-contained as possible. I will introduce the needed elements of field and gauge theory, general relativity, supersymmetry, supergravity, strings and conformal field theory. Then I describe the basic AdS-CFT scenario, of ${\\cal N}=4 $ Super Yang-Mills's relation to string theory in $AdS_5\\times S_5$, and applications that can be derived from it: 3-point functions, quark-antiquark potential, finite temperature and scattering processes, the pp wave correspondence and spin chains. I also describe some general properties of gravity duals of gauge theories.
Underweight Seniors May Have Added Alzheimer's Risk
... fullstory_160278.html Underweight Seniors May Have Added Alzheimer's Risk Study links lower body weight to increased ... older adults' risk of the memory-robbing disorder Alzheimer's disease, new research suggests. The study included 280 ...
Zhang, Jia-Lin; Yu, Hongwei
2014-01-01
We study thermodynamics and thermodynamic geometry of a five-dimensional Schwarzschild AdS black hole in $AdS_5\\times{S^5}$ spacetime by treating the cosmological constant as the number of colors in the boundary gauge theory and its conjugate quantity as the associated chemical potential. It is found that the chemical potential is always negative in the stable branch of black hole thermodynamics and it has a chance to be positive, but appears in the unstable branch. We calculate scalar curvatures of the thermodynamical Weinhold metric, Ruppeiner metric and Quevedo metric, respectively and we find that the divergence of scalar curvature is related to the divergence of specific heat with fixed chemical potential in the Weinhold metric and Ruppeiner metric, while in the Quevedo metric the divergence of scalar curvature is related to the divergence of specific heat with fixed number of colors and the vanishing of the specific heat with fixed chemical potential.
Women May Need Added Therapy for Rosacea
... Grants for Rosacea Research Women May Need Added Therapy Rosacea can be a trying condition under the best ... or recommend any particular medications, products, equipment or treatments. Rosacea may vary substantially from one patient to another, ...
Genes Might Explain Hispanics' Added Longevity
... page: https://medlineplus.gov/news/fullstory_160528.html Genes Might Explain Hispanics' Added Longevity Differences in 'genetic ... Services, or federal policy. More Health News on: Genes and Gene Therapy Hispanic American Health Recent Health ...
Multilevel security model for ad hoc networks
Institute of Scientific and Technical Information of China (English)
Wang Changda; Ju Shiguang
2008-01-01
Modern battlefield doctrine is based on mobility, flexibility, and rapid response to changing situations.As is well known, mobile ad hoc network systems are among the best utilities for battlefield activity. Although much research has been done on secure routing, security issues have largely been ignored in applying mobile ad hoc network theory to computer technology. An ad hoc network is usually assumed to be homogeneous, which is an irrational assumption for armies. It is clear that soldiers, commanders, and commanders-in-chief should have different security levels and computation powers as they have access to asymmetric resources. Imitating basic military rank levels in battlefield situations, how multilevel security can be introduced into ad hoc networks is indicated, thereby controlling restricted classified information flows among nodes that have different security levels.
A guide to gauging ad effectiveness.
Cashill, J
1987-09-01
Techniques that have proven successful in private industry can help hospital executives increase their accountability for advertising expenditures. Among these techniques are: The random telephone survey, which can be used to measure whether the hospital's awareness level among the public has increased as the result of a particular ad; The focus group, which assists the hospital in evaluating how it is perceived in relation to other hospitals in its market; The pretest, to determine which ads to eliminate from a campaign and which ones to refine; Educational seminars and direct-response ads; Reliable baseline data on patients and services for use in comparing figures before and after an ad has been used. Above all, careful planning is required to enable the marketing staff to determine what it wishes to accomplish through advertising and to set measurable goals that reflect its expectations for each component of a campaign. PMID:10283482
Trust Based Routing in Ad Hoc Network
Talati, Mikita V.; Valiveti, Sharada; Kotecha, K.
Ad Hoc network often termed as an infrastructure-less, self- organized or spontaneous network.The execution and survival of an ad-hoc network is solely dependent upon the cooperative and trusting nature of its nodes. However, this naive dependency on intermediate nodes makes the ad-hoc network vulnerable to passive and active attacks by malicious nodes and cause inflict severe damage. A number of protocols have been developed to secure ad-hoc networks using cryptographic schemes, but all rely on the presence of trust authority. Due to mobility of nodes and limitation of resources in wireless network one interesting research area in MANET is routing. This paper offers various trust models and trust based routing protocols to improve the trustworthiness of the neighborhood.Thus it helps in selecting the most secure and trustworthy route from the available ones for the data transfer.
International Nuclear Information System (INIS)
This document assumes that you have read and understood the Wingz user's manuals. CaWingz is an external Wingz program which, when combined with a set of script files, provides easy-to-use EPICS channel access interface functions for Wingz users. The external function run allows Wingz user to invoke any Unix processor within caWingz. Few additional functions for accessing static database field and monitoring of value change event is available for EPICS users after release 3.11. The functions, script files, and usage are briefly described in this document. The script files supplied here serve as examples only. Users are responsible for generating their own spreadsheet and script files. CaWingz communicates with IOC through channel access function calls
International Trade Effects of Value Added Taxation
Paul Krugman; Martin Feldstein
1989-01-01
The actual value added tax systems used in many countries differ significantly from the completely general VAT that has been the focus of most economic analyses. In practice, VAT systems exempt broad classes of consumer goods and services. This has important implications for the effect of the VAT on international trade. A value added tax is sometimes advocated as a way of improving a country's international competitiveness because GATT rules permit the tax to be levied on imports and rebated ...
Narayanan, Sathya; Byun, YoungJoon; Cebrowski Institute; CSUMB, C.S.I.T. Program
2011-01-01
In conjunction with the NPS C.S. Department MWC Group, this research looks at establishing an Ad Hoc Peer-to-Peer network on cell phones, specifically using the Android OS. Work comprised of Android Device, Library, and Application Design. The Library used was AODV (Ad Hoc on demand Distance Vector) and hardware devices must be controlled directly in addition to application enhancements. A prototype has been created and communication was achieved. Future work to include enhancements to contro...
Massive Gravity in Ads and Minkowski Backgrounds
Porrati, M.
2004-01-01
I review some interesting features of massive gravity in two maximally symmetric backgrounds: Anti de Sitter space and Minkowski space. While massive gravity in AdS can be seen as a spontaneously broken, UV safe theory, no such interpretation exists yet in the flat-space case. Here, I point out the problems encountered in trying to find such completion, and possible mechanisms to overcome them.
Security Threats in Mobile Ad Hoc Network
Biswas, Kamanashis; Ali, Md. Liakat
2007-01-01
Mobile Ad Hoc Network (MANET) is a collection of communication devices or nodes that wish to communicate without any fixed infrastructure and pre-determined organization of available links. The nodes in MANET themselves are responsible for dynamically discovering other nodes to communicate. Although the ongoing trend is to adopt ad hoc networks for commercial uses due to their certain unique properties, the main challenge is the vulnerability to security attacks. A number of challenges like o...
Adding stress plot function to NASTRAN
Katoh, S.
1978-01-01
Stress plot function was developed and added to the NASTRAN level 15.5. Computed stress distribution can be displayed by this function, with vectors showing the principal stresses of the finite elements over the specified portions of the structure. NASTRAN is reviewed in the aspect of plotting capabilities. Stress tensor field is examined in preparation of stress display. Then the stress plot function as added to the NASTRAN is described. A sample plotout by this function is shown.
Classical Klein-Gordon solutions, symplectic structures and isometry actions on AdS spacetimes
Dohse, Max
2012-01-01
We study classical, real Klein-Gordon theory on Lorentzian Anti de Sitter ($\\AdS d$) spacetimes with spatial dimension $d$. We give a complete list of well defined and bounded Klein-Gordon solutions for three types of regions on AdS: slice (time interval times all of space), rod hypercylinder (all of time times solid ball in space), and tube hypercylinder (all of time times solid shell in space). Hypercylinder regions are of natural interest for AdS since the neighborhood of the AdS-boundary is a tube. For the solution spaces of our regions we find the actions induced by the AdS isometry group $\\SOgroup{2,d}$. For all three regions we find one-to-one correspondences between initial data and solutions on the regions. For rod and tube regions this initial data can also be given on the AdS boundary. We calculate symplectic structures associated to the solution spaces, and show their invariance under the isometry actions. We compare our results to the corresponding expressions for $(3\\pn1)$-dimensional Minkowski ...
Gauge Symmetries and Holographic Anomalies of Chern-Simons and Transgression AdS Gravity
Mora, Pablo
2014-01-01
We review the issue of gauge and gravitational anomalies with backgrounds, maybe offering a new outlook on some aspects of these questions. We compute the holographic anomalies of hypothetical theories dual, in the sense of the AdS-CFT correspondence, to Chern-Simons AdS gravities. Those anomalies are either gauge anomalies associated to the AdS gauge group of the theory or diffeomorphism anomalies, with each kind related to the other. As a result of using suitable action principles por Chern-Simons AdS gravities, coming from Transgression forms, we obtain finite results without the need for further regularization. Our results are of potential interest for Lovelock gravity theories, as it has been shown that the boundary terms dictated by the transgressions for Chern-Simons gravities are also suitable to regularize Lovelock theories. The Wess-Zumino consistency condition ensures that anomalies of the generic form computed here should appear for these and other theories.
AdS5×S(5) mirror model as a string sigma model.
Arutyunov, Gleb; van Tongeren, Stijn J
2014-12-31
Doing a double Wick rotation in the world sheet theory of the light cone AdS5×S(5) superstring results in an inequivalent, so-called mirror theory that plays a central role in the field of integrability in the AdS-CFT correspondence. We show that this mirror theory can be interpreted as the light cone theory of a free string on a different background. This background is related to dS5×H(5) by a double T-duality, and has hidden supersymmetry. The geometry can also be extracted from an integrable deformation of the AdS5×S(5) sigma model, and we prove the observed mirror duality of these deformed models at the bosonic level as a byproduct. While we focus on AdS5×S(5), our results apply more generally.
Effects of nitrogen ion implantation on Ca2+ concentration and membrane potential of pollen cell
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
The effects of low energy nitrogen ion implantation on Ca2+ concentration and membrane potential of lily (lilium davidii Duch) pollen cell have been studied. The results showed that the Ca2+ concentration was increased when pollen grain was implanted by nitrogen ion with energy 100keV and dose 1013 ions/cra2. However, the increase of Ca2+ concentration was partly inhibited by the addition of Ca2+channel inhibitor depending on dose. And nitrogen ion implantation caused depolarization of pollen cell membrane potential. In other words, membrane potential was increased,but the effect decreased by adding Ca2+ channel inhibitor.However, it was still significantly higher than the membrane potential of control cells. It was indicated that the depolarization of cell membrane potential opened the calcium channel on the membrane that caused the increasing of intraceilular calcium concentration. This might be an earlier step of the effect of low energy nitrogen ion implantation on pollen germination.
Influence of green tea polyphenols on mitochondrial permeabi lity transition pore and Ca2+ transport
Institute of Scientific and Technical Information of China (English)
沈生荣; 于海宁; 金超芳
2002-01-01
The authors investigated the influence of green tea polyphenols (GTPs) on the liver mitochondria permeability transition pore (PTP) opening through mit ochondria swelling and change of mitochondria membrane potential. The data showe d that GTPs had obvious protective effect on the Ca2+-induced PTP opening in a d ose-dependent manner detected by mitochondria swelling. The results were obtain ed by measuring the change of mitochondria membrane potential through Rh 123. Further experiments were conducted to examine the detailed influence of GTP s on Ca2+import and export of mitochondria. The results showed that GTPs h ad rem arkably inhibitory effect on the Ca2+-induced Ca2+ import in mitoch ondria; and t hat they could accelerate Ca2+-release from mitochondria. Our data provid e an al ternate interpretation of the potent protective function of GTPs on cell against apoptosis.
Integrable strings for AdS/CFT
Borsato, Riccardo
2016-01-01
In this PhD thesis we review some aspects of integrable models related to string backgrounds or their deformations. In the first part we develop methods to obtain exact results in the AdS3/CFT2 correspondence. We consider the AdS_3 x S^3 x T^4 background with pure Ramond-Ramond flux and we find the all-loop worldsheet S-matrix by exploiting the symmetries of the model in light-cone gauge. As we naturally include the massless modes on the worldsheet, we derive the full set of Bethe-Yang equations. In the massive sector we give also a spin-chain description and we write down solutions compatible with crossing for the scalar factors which are not constrained by simmetries. In the second part of the thesis we consider the so-called "eta-deformation" of the superstring on AdS_5 x S^5. We first discuss the effects of the deformation at the level of the bosonic sigma-model, and we match the tree-level worldsheet scattering processes to the expansion of the q-deformed S-matrix. To identify the missing Ramond-Ramond f...
ADS specific accelerator developments: Status in Japan
International Nuclear Information System (INIS)
In Japan, JAEA proposes an ADS which consists of a high power proton LINAC, a spallation target of lead-bismuth eutectic (LBE) and a subcritical core. In this proposal, the energy and beam power of the high power proton LINAC are 1.5 GeV and 20–30 MW, respectively. Other specifications of the high power proton linac are described in [4.28]. An important technical aspect that is considered in the JAEA work is the negative impact of very frequent beam trips as experienced in existing intense accelerator facilities. Frequent beam trips cause thermal fatigue problems for ADS components materials, leading to degradation of their structural integrity and reduction of their lifetime. They can also badly erode the availability or the capacity of ADS, resulting in poor economics. In the development of accelerators for ADS, it is vitally important to establish the technologies to achieve a very high degree of reliability. On the other hand, JAEA considers that it is also important in the development of ADS to design structural components to withstand possible thermal fatigues and a power conversion system less sensitive to beam trips. The purpose of the JAEA study is the comparison of beam trip frequencies between requirement from ADS transient analyses and estimation from current experimental data of accelerators
Pecze, László; Blum, Walter; Schwaller, Beat
2015-11-20
In some cell types, Ca(2+) oscillations are strictly dependent on Ca(2+) influx across the plasma membrane, whereas in others, oscillations also persist in the absence of Ca(2+) influx. We observed that, in primary mesothelial cells, the plasmalemmal Ca(2+) influx played a pivotal role. However, when the Ca(2+) transport across the plasma membrane by the "lanthanum insulation method" was blocked prior to the induction of the serum-induced Ca(2+) oscillations, mitochondrial Ca(2+) transport was found to be able to substitute for the plasmalemmal Ca(2+) exchange function, thus rendering the oscillations independent of extracellular Ca(2+). However, in a physiological situation, the Ca(2+)-buffering capacity of mitochondria was found not to be essential for Ca(2+) oscillations. Moreover, brief spontaneous Ca(2+) changes were observed in the mitochondrial Ca(2+) concentration without apparent changes in the cytosolic Ca(2+) concentration, indicating the presence of a mitochondrial autonomous Ca(2+) signaling mechanism. In the presence of calretinin, a Ca(2+)-buffering protein, the amplitude of cytosolic spikes during oscillations was decreased, and the amount of Ca(2+) ions taken up by mitochondria was reduced. Thus, the increased calretinin expression observed in mesothelioma cells and in certain colon cancer might be correlated to the increased resistance of these tumor cells to proapoptotic/pronecrotic signals. We identified and characterized (experimentally and by modeling) three Ca(2+) shuttling pathways in primary mesothelial cells during Ca(2+) oscillations: Ca(2+) shuttled between (i) the endoplasmic reticulum (ER) and mitochondria, (ii) the ER and the extracellular space, and (iii) the ER and cytoplasmic Ca(2+) buffers.
Institute of Scientific and Technical Information of China (English)
周秀会
2007-01-01
结合作者使用 CA On CD 的经验和体会,全面而具体地分析了 CA on CD 的使用功能,明确了其优点及不足之处,同时,针对这些不足之处进行了探索和尝试,提出了利用检索技巧解决这些不足之处的方法。并结合实例详细说明。
Compound Method to Disperse CaCO3 Nanoparticles to Nano-Size in Water.
Gu, Sui; Cai, Jihua; Wang, Jijun; Yuan, Ye; Chang, Dewu; Chikhotkin, Viktor F
2015-12-01
The invalidation of CaCO3 nanoparticles (nCaCO3) is often caused by the fact of agglomeration and inhomogeneous dispersion which limits its application into water-based drilling muds for low permeability reservoirs such as coalbed methane reservoir and shale gas/oil reservoir. Effective methods to disperse nCaCO3 to nano-size (≤ 100 nm) in water have seldom been reported. Here we developed a compound method containing mechanical stirring, ultrasonic treatment, the use of surfactant and stabilizer to disperse nCaCO3 in water. It comprises the steps adding 2% nCaCO3, 1% sodium dodecyl sulfonate (SDS), 2% cetyltrimethyl ammonium bromide (CTAB), 2% OP-10, 3% to 4% biopolymer (XC) in water successively, stirring it at a shear rate of 6000 to 8000 r/min for 15 minutes and treating it with ultrasonic at a frequency of 28 KHz for 30 to 40 minutes. The dispersed nCaCO3 was characterized with scanning electron microscope (SEM), transmission electron microscope (TEM) and particle size distribution (PSD) tests. We found that nCaCO3 could be dispersed to below 100 nm in water and the medium value of nCaCO3 was below 50 nm. This method paved the way for the utilization of nCaCO3 in drilling fluid and completion fluid for low permeability reservoirs such as coal seams and shale gas/oil formations. PMID:26682370
Institute of Scientific and Technical Information of China (English)
ZHAO Huazhang; GE Xiaopeng; LUAN Zhaokun; JIANG Zhanpeng
2004-01-01
The flocculation efficiency of polyaluminum chloride (PAC) is closely related to the distribution and structure of its Al species, and Al13 is the optimal species in PAC for fiocculation. A series of PAC containing Ca was prepared by adding Ca before and after the basifying reaction. The effects of Ca on the Al species were studied by 27Al nuclear magnetic resonance (NMR) and atomic force microscope (AFM) techniques. The experimental results show that the introduction of Ca increases the content of Aim and Al13 in PAC and decreases their chemical shifts in NMR spectra due to the electric repulsion between the positive Ca species and Al species and the formation of Al-O-Ca complexes.With the rise of Ca/AI molar ratio, the Al species in PAC tend to scatter. It is observed that the formerly branch-aggregated clusters are tending to form granule-aggregated ones whose diameter gets smaller and smaller, and the fioccule aggregates are formed at a higher Ca/Al molar ratio. The introduction of Ca to PAC, which increases the Al13 content, is certainly to enhance the fiocculation efficiency of PAC in water treatment.
The diagnostic value of joint detection of serum CA19-9, CA125 and CA242 for cholangiocarcinoma
Institute of Scientific and Technical Information of China (English)
Cui Da-Peng; Han Lei; Liu Zhen-Xian; Yang He; Zhang Ying-Chun
2016-01-01
Objective:To study the diagnostic value of joint detection of serum CA19-9, CA125 and CA242 for cholangiocarcinoma.Methods:A total of 35 patients with cholangiocarcinoma who received surgical resection in our hospital were selected as malignant group, 30 patients with cholelithiasis who received surgical resection in our hospital during the same period were selected as benign group, serum samples were collected before surgery to determine CA19-9, CA125 and CA242 content, and cholangiocarcinoma tissue and normal bile duct tissue were collected after surgery to determine the content of proliferation and invasion molecules. Results:Serum CA19-9, CA125 and CA242 levels of malignant group were significantly higher than those of control group; PROX-1, Ki-67, Bcl-2, Bad, Gab1, LOXL2, TRPM7 and CXCL12 levels in cholangiocarcinoma tissue were higher than those in benign bile duct tissue, and E-cadherin level was lower than that in benign bile duct tissue; serum CA19-9, CA125 and CA242 levels were positively correlated with PROX-1, Ki-67, Bcl-2, Bad, Gab1, LOXL2, TRPM7 and CXCL12 levels, and negatively correlated with E-cadherin level.Conclusion:Joint detection of serum CA19-9, CA125 and CA242 can not only provide reference for the diagnosis of cholangiocarcinoma, but can also provide basis for the evaluation of proliferation, invasion and other malignant biological behaviors.
Institute of Scientific and Technical Information of China (English)
YANG Ming-bo; MA Yan-long; PAN Fu-sheng
2009-01-01
The effects of little Ce addition on the as-cast microstructure and creep properties of Mg-3Sn-2Ca magnesium alloy were investigated. The results indicate that adding 0.5% (mass fraction) Ce to Mg-3Sn-2Ca alloy does not cause the formation of any new phase in the alloy. However, an interesting microstructural change in the as-cast Mg-3Sn-2Ca alloy added with 0.5%Ce is observed. After adding 0.5%Ce to Mg-3Sn-2Ca alloy, not only the volume fraction of CaMgSn phase in the alloy is decreased but also the CaMgSn phases in the alloy are refined. In addition, adding 0.5%Ce to Mg-3Sn-2Ca alloy can also improve the creep-resistant properties of the alloy. After adding 0.5%Ce to Mg-3Sn-2Ca alloy, the second creep rate of the alloy at 150 ℃ and 70 Mpa for 100 h changes from 3.28×10~(-8) to 1.81×10~(-8) s~(-1).
Isotopic Effects on Stereodynamics for Ca+HCI, Ca+DCI, and Ca+TClReactions
Institute of Scientific and Technical Information of China (English)
Li-zhi Wang; Chuan-lu Yang; Jing-juan Liang; Jing Xiao; Qing-gang Zhang
2011-01-01
The vector correlations in Ca+HC1,Ca+DCI,and Ca+TCI reactions have been investigated by means of the quasi-classical trajectory calculations on PES constructed by means of multireference configuration interaction.The distributions of P(θr),P(Φr) and the PDDCSs of (2π/σ)(dσ00/dωt),(2π/σ)(dσ20/dωt),(2π/σ)(dσ22+/dωt),(2π/σ)(dσ21-/dωt) have been calculated based on the surface.The remarkable isotopic effects in the reactions are observed,and the mechanism which may be ascribed to different mass factors is discussed.
On the Thermodynamic Geometry and Critical Phenomena of AdS Black Holes
Sahay, Anurag; Sengupta, Gautam
2010-01-01
In this paper, we study various aspects of the equilibrium thermodynamic state space geometry of AdS black holes. We first examine the Reissner-Nordstrom-AdS (RN-AdS) and the Kerr-AdS black holes. In this context, the state space scalar curvature of these black holes are analysed in various regions of their thermodynamic parameter space. This provides important new insights into the structure and significance of the scalar curvature. We further investigate critical phenomena, and the behaviour of the scalar curvature near criticality, for KN-AdS black holes in two mixed ensembles, introduced and elucidated in our earlier work arXiv:1002.2538 [hep-th]. The critical exponents are identical to those in the RN-AdS and Kerr-AdS cases in the canonical ensemble. This suggests an universality in the scaling behaviour near critical points of AdS black holes. Our results further highlight qualitative differences in the thermodynamic state space geometry for electric charge and angular momentum fluctuations of these.
Interpolating from Bianchi Attractors to Lifshitz and AdS Spacetimes
Kachru, Shamit; Saha, Arpan; Samanta, Rickmoy; Trivedi, Sandip P
2013-01-01
We construct classes of smooth metrics which interpolate from Bianchi attractor geometries of Types II, III, VI and IX in the IR to Lifshitz or $AdS_2 \\times S^3$ geometries in the UV. While we do not obtain these metrics as solutions of Einstein gravity coupled to a simple matter field theory, we show that the matter sector stress-energy required to support these geometries (via the Einstein equations) does satisfy the weak, and therefore also the null, energy condition. Since Lifshitz or $AdS_2 \\times S^3$ geometries can in turn be connected to $AdS_5$ spacetime, our results show that there is no barrier, at least at the level of the energy conditions, for solutions to arise connecting these Bianchi attractor geometries to $AdS_5$ spacetime. The asymptotic $AdS_5$ spacetime has no non-normalizable metric deformation turned on, which suggests that furthermore, the Bianchi attractor geometries can be the IR geometries dual to field theories living in flat space, with the breaking of symmetries being either sp...
Higher spin contributions to holographic fluid dynamics in AdS5/CFT4
Lee, Seungjin; Polyakov, Dimitri
2014-08-01
We calculate the graviton's β function in the AdS string-theoretic sigma model, perturbed by vertex operators for Vasiliev's higher spin gauge fields in AdS5. The result is given by βmn=Rmn+4Tmn(g ,u) (with the AdS radius set to 1 and the graviton polarized along the AdS5 boundary), with the matter stress-energy tensor given by that of conformal holographic fluid in d =4, evaluated at the temperature given by T =1/π. The stress-energy tensor is given by Tmn=gmn+4umun+∑NTmn(N) where u is the vector excitation satisfying u2=-1 and N is the order of the gradient expansion in the dissipative part of the tensor. We calculate the contributions up to N =2. The higher spin excitations contribute to the β function, ensuring the overall Weyl covariance of the matter stress tensor. We conjecture that the structure of gradient expansion in d =4 conformal hydrodynamics at higher orders is controlled by the higher spin operator algebra in AdS5.
AdS and Lifshitz scalar hairy black holes in Gauss-Bonnet gravity
Chen, Bin; Fan, Zhong-Ying; Zhu, Lu-Yao
2016-09-01
We consider Gauss-Bonnet (GB) gravity in general dimensions, which is nonminimally coupled to a scalar field. By choosing a scalar potential of the type V (ϕ )=2 Λ0+1/2 m2ϕ2+γ4ϕ4 , we first obtain large classes of scalar hairy black holes with spherical/hyperbolic/planar topologies that are asymptotic to locally anti- de Sitter (AdS) space-times. We derive the first law of black hole thermodynamics using Wald formalism. In particular, for one class of the solutions, the scalar hair forms a thermodynamic conjugate with the graviton and nontrivially contributes to the thermodynamical first law. We observe that except for one class of the planar black holes, all these solutions are constructed at the critical point of GB gravity where there exist unique AdS vacua. In fact, a Lifshitz vacuum is also allowed at the critical point. We then construct many new classes of neutral and charged Lifshitz black hole solutions for an either minimally or nonminimally coupled scalar and derive the thermodynamical first laws. We also obtain new classes of exact dynamical AdS and Lifshitz solutions which describe radiating white holes. The solutions eventually become AdS or Lifshitz vacua at late retarded times. However, for one class of the solutions, the final state is an AdS space-time with a globally naked singularity.
The Impact of Ad Characteristics on Adolescents’ Attitudes Towards Antismoking Ads
Directory of Open Access Journals (Sweden)
Domen Bajde
2008-03-01
Full Text Available Smoking exerts a considerable burden not only on those who smoke but just as well on society at large. In response, governments and institutions often resort to advertising which aims to discourage smoking. Unfortunately, our knowledge of the workings of antismoking advertising is detrimentally limited. In particular, the literature delving into the impact of antismoking ad characteristics (e. g., ad content, valence, intensity on the overall effectiveness of antismoking advertising is scarce and contradictory. This empirical study aims to enhance the knowledge of antismoking advertising by presenting results of the survey involving Slovene adolescents. The adolescents were first exposed to advertisements of different antismoking ad contents (for the purpose of this study the term ‘ad content’ refers to types of appeals used in antismoking advertising, ad valence and intensity, and later invited to respond to a number of questions measuring their attitudes toward the ads, their attitudes toward smoking, their intentions to smoke, etc. The results indicate that while the different intensity and valence of ads produce varying attitudes toward the ads, we could not confirm these differences based on ad content. Also, we found that adolescent smokers respond to antismoking ads differently than do their nonsmoking peers. Our findings offer several important implications for antismoking advertisers and the research community interested in the workings of antismoking advertising.
Extended supersymmetric sigma models in AdS_4 from projective superspace
Butter, Daniel; Lindstrom, Ulf; Tartaglino-Mazzucchelli, Gabriele
2012-01-01
There exist two superspace approaches to describe N=2 supersymmetric nonlinear sigma models in four-dimensional anti-de Sitter (AdS_4) space: (i) in terms of N=1 AdS chiral superfields, as developed in arXiv:1105.3111 and arXiv:1108.5290; and (ii) in terms of N=2 polar supermultiplets using the AdS projective-superspace techniques developed in arXiv:0807.3368. The virtue of the approach (i) is that it makes manifest the geometric properties of the N=2 supersymmetric sigma-models in AdS_4. The target space must be a non-compact hyperkahler manifold endowed with a Killing vector field which generates an SO(2) group of rotations on the two-sphere of complex structures. The power of the approach (ii) is that it allows us, in principle, to generate hyperkahler metrics as well as to address the problem of deformations of such metrics. Here we show how to relate the formulation (ii) to (i) by integrating out an infinite number of N=1 AdS auxiliary superfields and performing a superfield duality transformation. We al...
Holography of non-relativistic string on AdS5 x S5
International Nuclear Information System (INIS)
We discuss a holographic dual of a non-relativistic (NR) string on AdS5 x S5 . The NR string can be regarded as a semiclassical string around an AdS2 classical solution corresponding to a straight Wilson line in the gauge-theory side. The quadratic action with respect to the fluctuations is composed of free massive and massless scalars, and free massive fermions on the AdS2 world-sheet. We show that the complete agreement of the spectra between the NR string and a conformal quantum mechanics (CQM). Then we show a holographic relation between normalizable modes of the NR string and wave functions in the CQM. Then it may be argued from this result that an AdS2/CFT1 would be realized in AdS5/CFT4. We can really discuss a GKPW-type relation by considering non-normalizable modes of the NR string in Euclidean signature. Those modes give a source term insertion to the Wilson line, which can also be regarded as a small deformation of it
EMRE Is a Matrix Ca(2+) Sensor that Governs Gatekeeping of the Mitochondrial Ca(2+) Uniporter.
Vais, Horia; Mallilankaraman, Karthik; Mak, Don-On Daniel; Hoff, Henry; Payne, Riley; Tanis, Jessica E; Foskett, J Kevin
2016-01-26
The mitochondrial uniporter (MCU) is an ion channel that mediates Ca(2+) uptake into the matrix to regulate metabolism, cell death, and cytoplasmic Ca(2+) signaling. Matrix Ca(2+) concentration is similar to that in cytoplasm, despite an enormous driving force for entry, but the mechanisms that prevent mitochondrial Ca(2+) overload are unclear. Here, we show that MCU channel activity is governed by matrix Ca(2+) concentration through EMRE. Deletion or charge neutralization of its matrix-localized acidic C terminus abolishes matrix Ca(2+) inhibition of MCU Ca(2+) currents, resulting in MCU channel activation, enhanced mitochondrial Ca(2+) uptake, and constitutively elevated matrix Ca(2+) concentration. EMRE-dependent regulation of MCU channel activity requires intermembrane space-localized MICU1, MICU2, and cytoplasmic Ca(2+). Thus, mitochondria are protected from Ca(2+) depletion and Ca(2+) overload by a unique molecular complex that involves Ca(2+) sensors on both sides of the inner mitochondrial membrane, coupled through EMRE.
XPS study of CaO in sodium silicate glass
International Nuclear Information System (INIS)
This paper shows that CaO added to silicate glasses behaves much like Na2O in converting bridging oxygen sites to nonbridging sites. Good correspondence with model predictions was obtained but deviations were still sufficiently large to warrant attention. We speculate that some CaO may remain unreacted or that small-scale phase separation may occur. XPS core level shifts were monitored and possible charge-transfer effects were considered. Preliminary theoretical calculations utilizing a molecular-cluster approach were presented. XPS spectra for various glass compositions were simulated by appropriately combining local densities of state calculated for individual atoms. Dominant spectral features observed experimentally were found in the simulations. In conjunction with experiments, more carefully refined calculations will be subsequently examined. 7 figures
Directory of Open Access Journals (Sweden)
Zsolt Pónya
2014-12-01
Full Text Available During in vitro fertilization of wheat (Triticum aestivum, L. in egg cells isolated at various developmental stages, changes in cytosolic free calcium ([Ca2+]cyt were observed. The dynamics of [Ca2+]cyt elevation varied, reflecting the difference in the developmental stage of the eggs used. [Ca2+]cyt oscillation was exclusively observed in fertile, mature egg cells fused with the sperm cell. To determine how [Ca2+]cyt oscillation in mature egg cells is generated, egg cells were incubated in thapsigargin, which proved to be a specific inhibitor of the endoplasmic reticulum (ER Ca2+-ATPase in wheat egg cells. In unfertilized egg cells, the addition of thapsigargin caused an abrupt transient increase in [Ca2+]cyt in the absence of extracellular Ca2+, suggesting that an influx pathway for Ca2+ is activated by thapsigargin. The [Ca2+]cyt oscillation seemed to require the filling of an intracellular calcium store for the onset of which, calcium influx through the plasma membrane appeared essential. This was demonstrated by omitting extracellular calcium from (or adding GdCl3 to the fusion medium, which prevented [Ca2+]cyt oscillation in mature egg cells fused with the sperm. Combined, these data permit the hypothesis that the first sperm-induced transient increase in [Ca2+]cyt depletes an intracellular Ca2+ store, triggering an increase in plasma membrane Ca2+ permeability, and this enhanced Ca2+ influx results in [Ca2+]cyt oscillation.
Energy Technology Data Exchange (ETDEWEB)
Qi, Liqian; Liu, Jiaxiang; Liu, Qian, E-mail: ljxpost@263.net [Beijing Key Laboratory of Electrochemical Process and Technology for Materials, The State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing (China)
2016-03-15
In this study, we replaced 30% of the cement with steel slag to prepare binding material; additionally, small amounts of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O were added. This was done to study the compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O on the strength of steel slag-cement binding materials. The hydration degree of the steel slag cementitious material was analyzed by XRD, TG and SEM. The results showed that the optimum proportions of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O were 3% and 2%, respectively. Compared with the steel slag-cement binders without adding CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O, the compressive strength increased by 59.9% at 3 days and by 17.8% at 28 days. Acting as the nucleation matrix, CaCO{sub 3} could accelerate the hydration of C{sub 3}S. In addition, CaCO{sub 3} was involved in the hydration reaction, generating a new hydration product, which could stably exist in a slurry. Meanwhile, CaSO{sub 4}·2H{sub 2}O could increase the number of AFt. The compound effect of CaCO{sub 3} and CaSO{sub 4}·2H{sub 2}O enhanced the intensity of steel slag-cement binding materials and improved the whole hydration behavior. (author)
Kay, Bernard S.; Ortíz, L.
2014-05-01
We discuss the relationship between the bulk-boundary correspondence in Rehren's algebraic holography (and in other `fixed-background', QFT-based, approaches to holography) and in mainstream string-theoretic `Maldacena AdS/CFT'. Especially, we contrast the understanding of black-hole entropy from the point of view of QFT in curved spacetime—in the framework of 't Hooft's `brick wall' model—with the understanding based on Maldacena AdS/CFT. We show that the brick-wall modification of a Klein-Gordon field in the Hartle-Hawking-Israel state on dimensional Schwarzschild AdS has a well-defined boundary limit with the same temperature and entropy as the brick-wall-modified bulk theory. One of our main purposes is to point out a close connection, for general AdS/CFT situations, between the puzzle raised by Arnsdorf and Smolin regarding the relationship between Rehren's algebraic holography and mainstream AdS/CFT and the puzzle embodied in the `complementarity principle' proposed by Mukohyama and Israel in their work on the brick-wall approach to black hole entropy. Working on the assumption that similar results will hold for bulk QFT other than the Klein-Gordon field and for Schwarzschild AdS in other dimensions, and recalling the first author's proposed resolution to the Mukohyama-Israel puzzle based on his `matter-gravity entanglement hypothesis', we argue that, in Maldacena AdS/CFT, the algebra of the boundary CFT is isomorphic only to a proper subalgebra of the bulk algebra, albeit (at non-zero temperature) the (GNS) Hilbert spaces of bulk and boundary theories are still the `same'—the total bulk state being pure, while the boundary state is mixed (thermal). We also argue from the finiteness of its boundary (and hence, on our assumptions, also bulk) entropy at finite temperature, that the Rehren dual of the Maldacena boundary CFT cannot itself be a QFT and must, instead, presumably be something like a string theory.
International Programmes on ADS: European Commission
International Nuclear Information System (INIS)
Euratom research projects related to the design and the use of ADS facilities started in the 4th Framework Programme (FP4) (1996–2001) with the project ‘Impact of Accelerator Based Technologies on Nuclear Fission Safety—IABAT’. The overall objective of the IABAT project was a preliminary assessment of the potential of Accelerator Driven Systems for transmutation of radioactive waste and, additionally, for nuclear energy production with minimum waste generation. This first project was followed by a much larger ADS oriented programmes in the FP5 (2002–2005), FP6 (2005–2010) and FP7 (2008–2013). In the frame of the FP6, special attention was devoted to the EUROTRANS integrated Project (2005–2010), dedicated to study the transmutation of high level radioactive waste in an ADS. Based on the three FP5 Clusters FUETRA, BASTRA and TESTRA together with the PDS-XADS Project, the EUROTRANS Project was aimed to carry out a first advanced design of an approximately 50 to 100 MWth eXperimental facility (realization in a short term, say about 10 years) demonstrating the technical feasibility of Transmutation in an ADS (XT ADS), as well as to accomplish a generic conceptual design (several 100 MWth) of a modular European Facility for Industrial Transmutation (EFIT) (realisation in the long term)
Connectivity in finite ad-hoc networks
Institute of Scientific and Technical Information of China (English)
WANG HanXing; LU GuiLin; JIA WeiJia; ZHAO Wei
2008-01-01
Research on ad-hoc network connectivity has mainly focused on asymptotic results In the number of nodes in the network. For a one-dimensional ad-hoc network G1, assuming all the nodes are Independently uniform distributed in a closed Interval [O, Z](z ∈ R+), we derive a generic formula for the probability that the network is connected. The finite connected ad-hoc networks is analyzed. And we separately suggest necessary conditions to make the ad-hoc network to be connected in one and two dimensional cases, facing possible failed nodes (f-nodes). Based on the necessary condition and unit-disk assumption for the node transmission, we prove that the nodes of the connected two-dimensional ad-hoc networks (G2) can be di-vided into at most five different groups. For an f-node n0 in either of the five groups, we derive a close formula for the probability that there is at least one route between a pair of nodes in G2 - {no}.
Ad Hoc Access Gateway Selection Algorithm
Jie, Liu
With the continuous development of mobile communication technology, Ad Hoc access network has become a hot research, Ad Hoc access network nodes can be used to expand capacity of multi-hop communication range of mobile communication system, even business adjacent to the community, improve edge data rates. For mobile nodes in Ad Hoc network to internet, internet communications in the peer nodes must be achieved through the gateway. Therefore, the key Ad Hoc Access Networks will focus on the discovery gateway, as well as gateway selection in the case of multi-gateway and handover problems between different gateways. This paper considers the mobile node and the gateway, based on the average number of hops from an average access time and the stability of routes, improved gateway selection algorithm were proposed. An improved gateway selection algorithm, which mainly considers the algorithm can improve the access time of Ad Hoc nodes and the continuity of communication between the gateways, were proposed. This can improve the quality of communication across the network.
Inter-Cluster Routing Authentication for Ad Hoc Networks by a Hierarchical Key Scheme
Institute of Scientific and Technical Information of China (English)
Yueh-Min Huang; Hua-Yi Lin; Tzone-I Wang
2006-01-01
Dissimilar to traditional networks, the features of mobile wireless devices that can actively form a network without any infrastructure mean that mobile ad hoc networks frequently display partition due to node mobility or link failures. These indicate that an ad hoc network is difficult to provide on-line access to a trusted authority server. Therefore,applying traditional Public Key Infrastructure (PKI) security framework to mobile ad hoc networks will cause insecurities.This study proposes a scalable and elastic key management scheme integrated into Cluster Based Secure Routing Protocol (CBSRP) to enhance security and non-repudiation of routing authentication, and introduces an ID-Based internal routing authentication scheme to enhance the routing performance in an internal cluster. Additionally, a method of performing routing authentication between internal and external clusters, as well as inter-cluster routing authentication, is developed.The proposed cluster-based key management scheme distributes trust to an aggregation of cluster heads using a threshold scheme faculty, provides Certificate Authority (CA) with a fault tolerance mechanism to prevent a single point of compromise or failure, and saves CA large repositories from maintaining member certificates, making ad hoc networks robust to malicious behaviors and suitable for numerous mobile devices.
The AD775 cosmic event revisited: the Sun is to blame
Usoskin, I G; Ludlow, F; Beer, J; Friedrich, M; Kovaltsov, G A; Solanki, S K; Wacker, L
2013-01-01
Miyake et al. (henceforth M12) recently reported, based on 14C data, an extreme cosmic event ca. AD775. Using a simple model, M12 claimed that the event was too strong to be caused by a solar flare within the standard theory. This implied a new paradigm of either an impossibly strong solar flare or a very strong cosmic ray event of unknown origin occurred ca. AD775. We show that the strength of the event was significantly overestimated by M12. Several subsequent works have attempted to find a possible exotic source for such an event, but they are all based on incorrect estimates by M12. We revisit this event with analysis of new datasets and consistent theoretical modelling. We verified the experimental result for the AD775 event using independent datasets including 10Be series and newly measured 14C annual data. We surveyed available historical chronicles for astronomical observations for the AD770s to identify potential sightings of aurorae or supernovae. We interpreted the 14C measurements using an appropr...
Vacuum type space-like string surfaces in AdS_3 x S^3
Dorn, Harald; Kalousios, Chrysostomos; Megrelidze, Luka; Wuttke, Sebastian
2010-01-01
We construct and classify all space-like minimal surfaces in AdS_3 x S^3 which globally admit coordinates with constant induced metric on both factors. Up to O(2,2) x O(4) transformations all these surfaces, except one class, are parameterized by four real parameters. The classes of surfaces correspond to different regions in this parameter space and show quite different boundary behavior. Our analysis uses a direct construction of the string coordinates via a group theoretical treatment based on the map of AdS_3 x S^3 to SL(2,R) x SU(2). This is complemented by a cross check via standard Pohlmeyer reduction. After embedding in AdS_5 x S^5 we calculate the regularized area for solutions with a boundary spanned by a four point scattering s-channel momenta configuration.
Solutions in Bosonic String Field Theory and Higher Spin Algebras in AdS
Polyakov, Dimitri
2015-01-01
We find a class of analytic solutions in open bosonic string field theory, parametrized by the chiral copy of higher spin algebra in $AdS_3$. The solutions are expressed in terms of the generating function for the products of Bell polynomials in derivatives of bosonic space-time coordinates $X^m(z)$ of the open string, which form is determined in this work. The products of these polynomials form a natural operator algebra realizations of $W_\\infty$ (area-preserving diffeomorphisms), enveloping algebra of SU(2) and higher spin algebra in $AdS_3$. The class of SFT solutions found can, in turn, be interpreted as the "enveloping of enveloping", or the enveloping of $AdS_3$ higher spin algebra. We also discuss the extensions of this class of solutions to superstring theory and their relations to higher spin algebras in higher space-time dimensions.
Analytical study on holographic superfluid in AdS soliton background
Lai, Chuyu; Pan, Qiyuan; Jing, Jiliang; Wang, Yongjiu
2016-06-01
We analytically study the holographic superfluid phase transition in the AdS soliton background by using the variational method for the Sturm-Liouville eigenvalue problem. By investigating the holographic s-wave and p-wave superfluid models in the probe limit, we observe that the spatial component of the gauge field will hinder the phase transition. Moreover, we note that, different from the AdS black hole spacetime, in the AdS soliton background the holographic superfluid phase transition always belongs to the second order and the critical exponent of the system takes the mean-field value in both s-wave and p-wave models. Our analytical results are found to be in good agreement with the numerical findings.
Banados and SUSY: On Supersymmetry and Minimal Surfaces of Locally AdS3 Geometries
Colgáin, E Ó
2016-01-01
We extend the classification of supersymmetric locally AdS$_3$ geometries, beyond BTZ black holes, to the Ba\\~nados geometries, noting that supersymmetries are in one-to-one correspondence with solutions to the Hill differential condition. We show that the number of global supersymmetries is an orbit invariant quantity and identify geometries with zero, one, two, three and four global supersymmetries. As an application of our classification, we exploit supersymmetry, which is preserved locally in the bulk, to determine space-like co-dimension two surfaces in AdS$_3$. In the process, we by-pass geodesics or mappings of AdS$_3$, neither of which have an analogue in higher dimensions, to recover known Hubeny-Rangamani-Takayanagi surfaces. Our findings suggest supersymmetry can be exploited to find extremal surfaces in holographic entanglement entropy.
Area products for ${\\cal H}^{\\pm}$ in AdS space
Pradhan, Parthapratim
2016-01-01
We derive the thermodynamic products particularly area (or entropy) products of ${\\cal H}^{\\pm}$ for certain class of black holes in AdS space. We show by explicit calculations that more complicated function of event horizon area and Cauchy horizon area is indeed mass-independent. This mass-independent quantities indicate that they could turn out to be an "universal" quantity provided that they depends only on the quantized angular momentum, quantized charges, and cosmological constant. Furthermore, these area (or entropy) product relations for several class of black holes in AdS space gives us strong indication to understanding the nature of non-extremal black hole entropy (both inner and outer) at the microscopic level. Moreover, we compute the famous \\emph{Penrose inequality} for these class of black holes in AdS space. Local thermodynamic stability has been discussed for these black holes and under certain condition these black holes displayed second order phase transition.
Photon gas thermodynamics in dS and AdS momentum spaces
Gorji, M A; Nozari, K; Vakili, B
2016-01-01
In this paper, we study thermostatistical properties of a photon gas in the framework of two deformed special relativity models defined by the cosmological coordinatizations of the de Sitter (dS) and anti-de Sitter (AdS) momentum spaces. The dS model is a doubly special relativity theory in which an ultraviolet length scale is invariant under the deformed Lorentz transformations. For the case of AdS model, however, the Lorentz symmetry breaks at the high energy regime. We show that the existence of a maximal momentum in dS momentum space leads to maximal pressure and temperature at the thermodynamical level while maximal internal energy and entropy arise for the case of the AdS momentum space due to the existence of a maximal kinematical energy. These results show the thermodynamical duality of these models much similar to their well-known kinematical duality.
Photon gas thermodynamics in dS and AdS momentum spaces
Gorji, M. A.; Hosseinzadeh, V.; Nozari, K.; Vakili, B.
2016-07-01
In this paper, we study thermostatistical properties of a photon gas in the framework of two deformed special relativity models defined by the cosmological coordinatizations of the de Sitter (dS) and anti-de Sitter (AdS) momentum spaces. The dS model is a doubly special relativity theory in which an ultraviolet length scale is invariant under the deformed Lorentz transformations. For the case of the AdS model, however, the Lorentz symmetry breaks at the high energy regime. We show that the existence of a maximal momentum in dS momentum space leads to maximal pressure and temperature at the thermodynamical level, while maximal internal energy and entropy arise for the case of the AdS momentum space due to the existence of a maximal kinematical energy. These results show that the thermodynamical duality of these models is very similar to their well-known kinematical duality.
Spinning strings in AdS3×S3 with NS–NS flux
Directory of Open Access Journals (Sweden)
Rafael Hernández
2014-11-01
Full Text Available The sigma model describing closed strings rotating in AdS3×S3 is known to reduce to the one-dimensional Neumann–Rosochatius integrable system. In this article we show that closed spinning strings in AdS3×S3×T4 in the presence of NS–NS three-form flux can be described by an extension of the Neumann–Rosochatius system. We consider closed strings rotating with one spin in AdS3 and two different angular momenta in S3. For a class of solutions with constant radii we find the dependence of the classical energy on the spin and the angular momenta as an expansion in the square of the 't Hooft coupling of the theory.
Asymptotically AdS Solutions of Five Dimensional Gravity-Dilaton Theory
Nata Atmaja, Ardian
2016-08-01
We search for Asymptotically AdS solutions of the background metric in which dilaton back reacts to gravity in five-dimensional gravity-dilaton theory. The five-dimensional gravity-dilaton theory generally appears in the context of the low energy effective action of closed string theory in the Einstein frame. In particular, we consider dilaton which are minimally coupled to gravity in which the potential for dilation is taken to be simple and contain only one exponential term parametrized by a constant a. We solve analytically and show for a simple constant dilaton potential it appears there are no black hole solutions if we turn on the dilaton contribution. On the other hand, the exponential dilaton potential has black hole solutions but they are not in general Asymptotically AdS. We argue that there are some possible Asymptotically AdS black hole solutions in the range of |a| \\lt \\frac{4}{\\sqrt{6}}
On thermodynamics of AdS black holes in M-theory
Energy Technology Data Exchange (ETDEWEB)
Belhaj, A. [Universite Sultan Moulay Slimane, Departement de Physique, LIRST, Faculte Polydisciplinaire, Beni Mellal (Morocco); Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); Chabab, M.; Masmar, K. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); El Moumni, H. [Cadi Ayyad University, High Energy Physics and Astrophysics Laboratory, FSSM, Marrakesh (Morocco); Universite Ibn Zohr, Departement de Physique, Faculte des Sciences, Agadir (Morocco); Sedra, M.B. [Universite Ibn Tofail, Departement de Physique, LASIMO, Faculte des Sciences, Kenitra (Morocco)
2016-02-15
Motivated by recent work on asymptotically AdS{sub 4} black holes in M-theory, we investigate the thermodynamics and thermodynamical geometry of AdS black holes from M2- and M5-branes. Concretely, we consider AdS black holes in AdS{sub p+2} x S{sup 11-p-2}, where p = 2,5 by interpreting the number of M2- (and M5-branes) as a thermodynamical variable. More precisely, we study the corresponding phase transition to examine their stabilities by calculating and discussing various thermodynamical quantities including the chemical potential. Then we compute the thermodynamical curvatures from the Quevedo metric for M2- and M5-branes geometries to reconsider the stability of such black holes. The Quevedo metric singularities recover similar stability results provided by the phase-transition program. It has been shown that similar behaviors are also present in the limit of large N. (orig.)
A Mean-Field Description for AdS Black Hole
Dutta, Suvankar
2016-01-01
In this paper we find an equivalent mean-field description for asymptotically $AdS$ black hole in high temperature limit and in arbitrary dimensions. We obtain a class of mean-field potential for which the description is valid. We explicitly show that there is an one to one correspondence between the thermodynamics of a gas of interacting particles moving under a mean-field potential and an $AdS$ black hole, namely the equation of state, temperature, pressure, entropy and enthalpy of both the systems match. In $3+1$ dimensions, in particular, the mean-field description can be thought of as an ensemble of tiny interacting {\\it asymptotically flat} black holes moving in volume $V$ and at temperature $T$. This motivates us to identify these asymptotically flat black holes as microstructure of asymptotically $AdS$ black holes in $3+1$ dimensions.
A Stochasticity Threshold in Holography and and the Instability of AdS
Basu, Pallab; Saurabh, Ayush
2014-01-01
We give strong numerical evidence that a self-interacting probe scalar field in AdS, with only a few modes turned on initially, will undergo fast thermalization only if it is above a certain energetic threshold. Below the threshold the energy stays close to constant in a few modes for a very long time instead of cascading quickly. This indicates the existance of a Strong Stochasticity Threshold (SST) in holography. The idea of SST is familiar from certain statistical mechanical systems, and we suggest that it exists also in AdS gravity. This would naturally reconcile the generic non-linear instability of AdS observed by Bizon and Rostworowski, with the Fermi-Pasta-Ulam-Tsingou-like quasi-periodocity noticed recently for some classes of initial conditions. We show that our simple set-up captures many of the relevant features of the full gravity-scalar system.
Conformally coupled scalars, instantons and vacuum instability in AdS4
International Nuclear Information System (INIS)
We show that a scalar field conformally coupled to AdS gravity in four dimensions with a quartic self-interaction can be embedded into M-theory. The holographic effective action and effective potential are exactly calculated, allowing us to study non-perturbatively the stability of AdS4 in the presence of the conformally coupled scalar. It is shown that there exists a one-parameter family of conformal scalar boundary conditions for which the boundary theory has an unstable vacuum. In this case, the bulk theory has instanton solutions that mediate the decay of the AdS4 space. These results match nicely with the vacuum structure and the existence of instantons in an effective three-dimensional boundary model
QCD Condensates and Holographic Wilson Loops for Asymptotically AdS Spaces
Energy Technology Data Exchange (ETDEWEB)
Quevedo, R. Carcasses [Instituto Balseiro, Centro Atomico Bariloche, 8400 San Carlos de Bariloche (Argentina); CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina); Goity, Jose L. [Hampton University, Hampton, VA 23668 (United States); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Trinchero, Roberto C. [Instituto Balseiro, Centro Atomico Bariloche, 8400 San Carlos de Bariloche (Argentina); CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina)
2014-02-01
The minimization of the Nambu-Goto (NG) action for a surface whose contour defines a circular Wilson loop of radius a placed at a finite value of the coordinate orthogonal to the border is considered. This is done for asymptotically AdS spaces. The condensates of dimension n = 2, 4, 6, 8, and 10 are calculated in terms of the coefficients in the expansion in powers of the radius a of the on-shell subtracted NG action for small a->0. The subtraction employed is such that it presents no conflict with conformal invariance in the AdS case and need not introduce an additional infrared scale for the case of confining geometries. It is shown that the UV value of the gluon condensates is universal in the sense that it only depends on the first coefficients of the difference with the AdS case.
Symmetries of the Boundary of $AdS_{5} \\times S^{5}$ and Harmonic Superspace
Claus, P; Rahmfeld, J; Claus, Piet; Kallosh, Renata
1999-01-01
We study the boundary limit of the bulk isometries of AdS x S. The superconformal symmetry is realized on the coordinates of the AdS boundary, the fermionic superspace coordinates, and the harmonics on the sphere. We show how these may be related to the coordinates of an off-shell harmonic superspace of SCFT living on the boundary. In the special case of d=4, N=2 super Yang-Mills theory, a truncation of the N=4 SYM dual to Type IIB string theory compactified on AdS_5 x S^5, we identify the bosonic space $SU(2)/U(1)$ of the N=2 harmonic superspace (known before as auxiliary) with the S^2 submanifold of the S^5.
2D Gravity on $AdS_2$ with Chern-Simons Corrections
Alishahiha, Mohsen; Mosaffa, Amir E
2009-01-01
We study 2D Maxwell-dilaton gravity with higher order corrections given by the Chern-Simons term. The model admits three distinctive $AdS_2$ vacuum solutions. By making use of the entropy function formalism we find the entropy of the solutions which is corrected due to the presence of the Chern-Simons term. We observe that the form of the correction depends not only on the coefficient of the Chern-Simons term, but also on the sign of the electric charge; pointing toward the chiral nature of the dual CFT. Using the asymptotic symmetry of the theory as well as requiring a consistent picture we can find the central charge and the level of U(1) current. Upon uplifting the solutions to three dimensions we get purely geometric solutions which will be either $AdS_3$ or warped $AdS_3$ with an identification.
Ad-blocking Games: Monetizing Online Content Under the Threat of Ad Avoidance
Vratonjic, Nevena; Manshaei, Mohammadhossein; Grossklags, Jens; Hubaux, Jean-Pierre
2012-01-01
Much of the Internet economy relies on online advertising for monetizing digital content: Users are expected to accept the presence of online advertisements in exchange for content being free. However, online advertisements have become a serious problem for many Internet users: while some are merely annoyed by the incessant display of distracting ads cluttering Web pages, others are highly concerned about the privacy implications - as ad providers typically track users' behavior for ad target...
Ad Hoc路由协议综述%Introduction to the Ad Hoc Network Routing Algorithms
Institute of Scientific and Technical Information of China (English)
赵根喜; 张爱红; 孙伟
2003-01-01
本文首先介绍了Ad hoc网络的特点和应用领域.然后对Ad hoc网络的路由协议进行了研究,给出了常见的几种路由协议算法.最后对Ad hoc网络路由进行了深入分析.
Wang, Jiamei; Chen, Xiuping; Li, Yunhe; Su, Changqing; Ding, Jiatong; Peng, Yufa
2014-08-01
The effect of purified Cry1Ca insecticidal protein on the growth of Chlorella pyrenoidosa was studied in a three-generation toxicity test. The C. pyrenoidosa medium with a density of 5.4 × 10(5) cells/mL was subcultured for three generations with added Cry1Ca at 0, 10, 100, and 1000 µg/L, and cell numbers were determined daily. To explore the distribution of Cry1Ca in C. pyrenoidosa and the culture medium, Cry1Ca was added at 1000 µg/L to algae with a high density of 4.8 × 10(6) cells/mL, and Cry1Ca content was determined daily in C. pyrenoidosa and the culture medium by enzyme-linked immunosorbent assays. Our results showed that the growth curves of C. pyrenoidosa exposed to 10, 100, and 1000 µg/L of Cry1Ca almost overlapped with that of the blank control, and there were no statistically significant differences among the four treatments from day 0 to day 7, regardless of generation. Moreover, the Cry1Ca content in the culture medium and in C. pyrenoidosa sharply decreased under exposure of 1000 µg/L Cry1Ca with high initial C. pyrenoidosa cell density. The above results demonstrate that Cry1Ca in water can be rapidly adsorbed and degraded by C. pyrenoidosa, but it has no suppressive or stimulative effect on algae growth.
Secure Clustering in Vehicular Ad Hoc Networks
Directory of Open Access Journals (Sweden)
Zainab Nayyar
2015-09-01
Full Text Available A vehicular Ad-hoc network is composed of moving cars as nodes without any infrastructure. Nodes self-organize to form a network over radio links. Security issues are commonly observed in vehicular ad hoc networks; like authentication and authorization issues. Secure Clustering plays a significant role in VANETs. In recent years, various secure clustering techniques with distinguishing feature have been newly proposed. In order to provide a comprehensive understanding of these techniques are designed for VANETs and pave the way for the further research, a survey of the secure clustering techniques is discussed in detail in this paper. Qualitatively, as a result of highlighting various techniques of secure clustering certain conclusions are drawn which will enhance the availability and security of vehicular ad hoc networks. Nodes present in the clusters will work more efficiently and the message passing within the nodes will also get more authenticated from the cluster heads.
International Programmes on ADS: OECD-NEA
International Nuclear Information System (INIS)
The present study compares FR and ADS based actinide transmutation systems with respect to reactor properties, fuel cycle requirements, economic aspects, and R&D needs. The essential differences between the various systems are evaluated with the help of a number of representative fuel cycle schemes. The strategies investigated include an evolutionary transmutation strategy in which the ADS provides additional flexibility by enabling plutonium utilisation in conventional reactors and confining the minor actinides to a small part of the fuel cycle, and two innovative transuranics (TRU) burning strategies, with an FR or an ADS, in which plutonium and minor actinides are managed together to minimize the proliferation risk. A novelty in the present study is that the analyses are carried out in a consistent manner using reactor and fuel cycle parameters which have been agreed upon by international experts
ADS National Programmes: Republic of Korea
International Nuclear Information System (INIS)
ADS research of Korea was carried out at KAERI (Korea Atomic Energy Research Institute) for the transmutation of long lived nuclides in spent fuels. The KAERI ADS system was called HYPER (HYbrid Power Extraction Reactor). The HYPER research was carried out as a 10 year nuclear research programme funded by the government. The ADS research of KAERI consisted of 3 phases. A basic concept of HYPER was established in the first phase (1997– 2000) of the development. The key technologies related to HYPER was studied in the second phase (2001–2003) while upgrading the design. The conceptual design of HYPER core was completed in the third phase (2004–2006). The research of key technologies was continued in the third phase. The research results can be summarized in three categories: Design and analysis; Fuel experiment; Pb-Bi experiment
Introduction to AdS/CFT correspondence
Nastase, Horatiu
2015-01-01
Providing a pedagogical introduction to the rapidly developing field of AdS/CFT correspondence, this is one of the first texts to provide an accessible introduction to all the necessary concepts needed to engage with the methods, tools and applications of AdS/CFT. Without assuming anything beyond an introductory course in quantum field theory, it begins by guiding the reader through the basic concepts of field theory and gauge theory, general relativity, supersymmetry, supergravity, string theory and conformal field theory, before moving on to give a clear and rigorous account of AdS/CFT correspondence. The final section discusses the more specialised applications, including QCD, quark-gluon plasma and condensed matter. This book is self-contained and learner-focused, featuring numerous exercises and examples. It is essential reading for both students and researchers across the fields of particle, nuclear and condensed matter physics.
Data Confidentiality in Mobile Ad hoc Networks
Aldabbas, Hamza; Janicke, Helge; Al-Bayatti, Ali; 10.5121/ijwmn.2012.4117
2012-01-01
Mobile ad hoc networks (MANETs) are self-configuring infrastructure-less networks comprised of mobile nodes that communicate over wireless links without any central control on a peer-to-peer basis. These individual nodes act as routers to forward both their own data and also their neighbours' data by sending and receiving packets to and from other nodes in the network. The relatively easy configuration and the quick deployment make ad hoc networks suitable the emergency situations (such as human or natural disasters) and for military units in enemy territory. Securing data dissemination between these nodes in such networks, however, is a very challenging task. Exposing such information to anyone else other than the intended nodes could cause a privacy and confidentiality breach, particularly in military scenarios. In this paper we present a novel framework to enhance the privacy and data confidentiality in mobile ad hoc networks by attaching the originator policies to the messages as they are sent between nod...
Value added meat marketing around the globe
DEFF Research Database (Denmark)
Grebitus, Carola; Mueller Loose, Simone
In highly competitive meat markets it is important to offer value added products to consumers. Thus, we need to understand which attributes are especially valued by consumers. This track session will contribute to a better understanding of consumer preferences for value added meats across different...... countries and simultaneously address different stages of the food chain by acknowledging factors such as breeding, forage (fat content), meat cuts as well as product labelling and packaging. Comparing consumers’ choices for value added pork and beef across different countries is the main theme and focus...... practices will be examined and the economic and technological dimensions of meat packaging will be related to each other presenting work from the US and Germany. Lastly, we will uncover the competitive nature between different beef cuts for Italian consumers....
Profiling value added position in FM
DEFF Research Database (Denmark)
Katchamart, Akarapong
the unarticulated notions of added value from FM organization and activities. It will broaden the managerial perception and discussion on FM provision ´s abilities and capabilities. The results are besides the field of FM also of relevance for management of other service industries and functions.......The dissertation is a research based contribution to the on-going professional discussion among researchers and practitioners within Facilities Management (FM) about whether and why FM organizations should be established with a managerial position which can act as a corporate strategic player...... organizations can best add value. Based on comprehensive literature studies and 7 case studies of private and public organisations from Denmark, Holland, Hong Kong and Thailand, the dissertation analyses, how FM organizations can best create added value. From the analyses the following four value added...
Online Stochastic Ad Allocation: Efficiency and Fairness
Feldman, Jon; Korula, Nitish; Mirrokni, Vahab S; Stein, Cliff
2010-01-01
We study the efficiency and fairness of online stochastic display ad allocation algorithms from a theoretical and practical standpoint. In particular, we study the problem of maximizing efficiency in the presence of stochastic information. In this setting, each advertiser has a maximum demand for impressions of display ads that will arrive online. In our model, inspired by the concept of free disposal in economics, we assume that impressions that are given to an advertiser above her demand are given to her for free. Our main theoretical result is to present a training-based algorithm that achieves a (1-\\epsilon)-approximation guarantee in the random order stochastic model. In the corresponding online matching problem, we learn a dual variable for each advertiser, based on data obtained from a sample of impressions. We also discuss different fairness measures in online ad allocation, based on comparison to an ideal offline fair solution, and develop algorithms to compute "fair" allocations. We then discuss sev...
A new multistep Ca2+-Induced Cold Gelation Process for ß-Lactoglobulin
Veerman, C.; Baptist, H.G.M.; Sagis, L.M.C.; Linden, van der E.
2003-01-01
The objective of this study was to obtain -lactoglobulin (-lg) gels at very low protein concentrations using a new multistep Ca2+-induced cold gelation process. In the conventional cold gelation process, salt free -lg solutions were heated at neutral pH, cooled, and cross-linked by adding salts. In
Environmental change in the Limfjord, Denmark (ca 7500-1500 cal yrs BP): A multiproxy study
DEFF Research Database (Denmark)
Lewis, J. P.; Ryves, D.B.; Rasmussen, P.;
2013-01-01
, foraminifera, sedimentary pigments, C and O stable isotopes and plant macrofossils) has been adopted to assess environmental change over the period ca 7500–1500 cal yrs BP at Kilen, a coastal fjord (before AD 1856) situated in the Western Limfjord. A diatom-based salinity transfer function based on a pan...
KOOREMAN, PA; ENGBERTS, JBFN
1994-01-01
The synthesis, critical micelle concentrations (CMC) and Krafft temperatures (T(Krafft)) of a series of disodium 2-(sulfatomethyl)-1-alkylsulfates (2a-d) are presented, with alkyl being n-tetradecyl (C-14), n-hexadecyl (C-16), n-octadecyl (C18) and n-eicosyl(C20). The surfactants exhibit a large Ca2
A Mean-Field Description for AdS Black Hole
Dutta, Suvankar; P, Sachin Shain
2016-01-01
In this paper we find an equivalent mean-field description for asymptotically $AdS$ black hole in high temperature limit and in arbitrary dimensions. We obtain a class of mean-field potential for which the description is valid. We explicitly show that there is an one to one correspondence between the thermodynamics of a gas of interacting particles moving under a mean-field potential and an $AdS$ black hole, namely the equation of state, temperature, pressure, entropy and enthalpy of both the...
Horizon Conformal Field Theories from $AdS_2$ Black Holes
Halyo, Edi
2015-01-01
We show that the very near horizon region of nonextreme black holes, which can be described by horizon CFTs, are related to $AdS_2$ Rindler spaces. The latter are $AdS_2$ black holes with specific masses and can be described by states of either $D=1$ or $D=2$ CFTs. The central charges of these CFTs and the conformal weights of their states that correspond to the nonextreme black holes exactly match those predicted by the horizon CFTs, providing supporting evidence for this description.
N=4 Supersymmetric AdS5 Vacua and their Moduli Spaces
Louis, Jan; Zagermann, Marco
2015-01-01
We classify the N=4 supersymmetric AdS5 backgrounds that arise as solutions of five-dimensional N=4 gauged supergravity. We express our results in terms of the allowed embedding tensor components and identify the structure of the associated gauge groups. We show that the moduli space of these AdS vacua is of the form SU(1,m)/(U(1)x SU(m)) and discuss our results regarding holographically dual N=2 SCFTs and their conformal manifolds.
Moduli spaces of AdS_5 vacua in N=2 supergravity
Louis, Jan
2016-01-01
We determine the conditions for maximally supersymmetric AdS_5 vacua of five-dimensional gauged N=2 supergravity coupled to vector-, tensor- and hypermultiplets charged under an arbitrary gauge group. In particular, we show that the unbroken gauge group of the AdS_5 vacua has to contain an U(1)_R-factor. Moreover we prove that the scalar deformations which preserve all supercharges form a Kahler submanifold of the ambient quaternionic Kahler manifold spanned by the scalars in the hypermultiplets.
Superradiance Instability of Small Rotating AdS Black Holes in Arbitrary Dimensions
Delice, Özgür
2015-01-01
We investigate the stability of $D$ dimensional singly rotating Myers-Perry-AdS black holes under superradiance against scalar field perturbations. It is well known that small four dimensional rotating or charged AdS black holes are unstable against superradiance instability of a scalar field. Recent works extended the existence of this instability to five dimensional rotating charged AdS black holes or static charged AdS Black holes in arbitrary dimensions. In this work we analytically prove that, rotating small AdS black holes in arbitrary dimensions also show superradiance instability irrespective of the value of the (positive) angular momentum quantum number. To do this we solve the Klein-Gordon equation in the slow rotation, low frequency limit. By using the asymptotic matching technique, we are able to calculate the real and imaginary parts of the correction terms to the frequency of the scalar field due to the presence of the black hole, confirming the presence of superradiance instability. We see that...
Flowing along the edge: spinning up black holes in AdS spacetimes with test particles
Rocha, Jorge V
2014-01-01
We investigate the consequences of throwing point particles into odd-dimensional Myers-Perry black holes in asymptotically anti-de Sitter (AdS) backgrounds. We restrict our attention to the case in which the angular momenta of the background geometry are all equal. This process allows us to test the generalization of the weak cosmic censorship conjecture to asymptotically AdS spacetimes in higher dimensions. We find no evidence for overspinning in D = 5, 7, 9 and 11 dimensions. Instead, test particles carrying the maximum possible angular momentum that still fall into an extremal rotating black hole generate a flow along the curve of extremal solutions.
Double-trace deformations and entanglement entropy in AdS
Energy Technology Data Exchange (ETDEWEB)
Miyagawa, Taiki [Department of Physics, Kyoto University (Japan); Shiba, Noburo [Yukawa Institute for Theoretical Physics (YITP), Kyoto University (Japan); Takayanagi, Tadashi [Yukawa Institute for Theoretical Physics (YITP), Kyoto University (Japan); Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU), University of Tokyo, Kashiwa, Chiba (Japan)
2016-01-15
We compute the bulk entanglement entropy of a massive scalar field in a Poincare AdS with the Dirichlet and Neumann boundary condition when we trace out a half space. Moreover, by taking into account the quantum back reaction to the minimal surface area, we calculate how much the entanglement entropy changes under a double-trace deformation of a holographic CFT. In the AdS3/CFT2 setup, our result agrees with the known result in 2d CFTs. In higher dimensions, our results offer holographic predictions. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Holography of Non-relativistic String on AdS5xS5
International Nuclear Information System (INIS)
We review a holography of a non-relativistic (NR) string on AdS5xS5. The NR string can be regarded as a semiclassical string around an AdS2 classical solution, which corresponds to a straight Wilson line in the gauge-theory side. Non-normalizable modes of the NR string correspond to string fluctuations reaching the boundary, and cause small deformations of the Wilson line. The operator inserted on the Wilson line are found from the small deformation of the Wilson line. Normalizable modes, which exist in the Lorentzian case, are considered as wave functions in a conformal quantum mechanics.
Half BPS states in AdS_5 x Y^{p,q}
Gava, Edi; Narain, Kumar S.; Milanesi, Giuseppe; O'Loughlin, Martin
2007-01-01
We study a class of solutions of IIB Supergravity which are asymptotically AdS_5 x Y^{p,q}. They have an R x SO(4) x SU(2) x U(1) isometry and preserve half of the 8 supercharges of the background geometry. They are described by a set of second order differential equations that we have found and analysed in a previous paper, where we studied 1/8 BPS states in the maximally supersymmetric AdS_5 x S^5 background. These geometries correspond to certain chiral primary operators of the N=1 superco...
Double-Trace Deformations and Entanglement Entropy in AdS
Miyagawa, Taiki; Takayanagi, Tadashi
2016-01-01
We compute the bulk entanglement entropy of a massive scalar field in a Poincare AdS with the Dirichlet and Neumann boundary condition when we trace out a half space. Moreover, by taking into account the quantum back reaction to the minimal surface area, we calculate how much the entanglement entropy changes under a double-trace deformation of a holographic CFT. In the AdS3/CFT2 setup, our result agrees with the known result in 2d CFTs. In higher dimensions, our results offer holographic predictions.
Integrable open spin-chains in AdS3/CFT2 correspondences
Prinsloo, Andrea(Department of Mathematics, University of Surrey, Guildford, GU2 7XH, United Kingdom); Regelskis, Vidas; Torrielli, Alessandro
2015-01-01
We study integrable open boundary conditions for d(2,1;\\alpha)^2 and psu(1,1|2)^2 spin-chains. Magnon excitations of these open spin-chains are mapped to massive excitations of type IIB open superstrings ending on D-branes in the AdS_3 x S^3 x S^3 x S^1 and AdS_3 x S^3 x T^4 supergravity geometries with pure R-R flux. We derive reflection matrix solutions of the boundary Yang-Baxter equation which intertwine representations of a variety of boundary coideal subalgebras of the bulk Hopf superal...
Ad hoc networks telecommunications and game theory
Benslama, Malek; Batatia, Hadj
2015-01-01
Random SALOHA and CSMA protocols that are used to access MAC in ad hoc networks are very small compared to the multiple and spontaneous use of the transmission channel. So they have low immunity to the problems of packet collisions. Indeed, the transmission time is the critical factor in the operation of such networks. The simulations demonstrate the positive impact of erasure codes on the throughput of the transmission in ad hoc networks. However, the network still suffers from the intermittency and volatility of its efficiency throughout its operation, and it switches quickly to the satura
Intermittently connected mobile ad hoc networks
Jamalipour, Abbas
2011-01-01
In the last few years, there has been extensive research activity in the emerging area of Intermittently Connected Mobile Ad Hoc Networks (ICMANs). By considering the nature of intermittent connectivity in most real word mobile environments without any restrictions placed on users' behavior, ICMANs are eventually formed without any assumption with regard to the existence of a end-to-end path between two nodes wishing to communicate. It is different from the conventional Mobile Ad Hoc Networks (MANETs), which have been implicitly viewed as a connected graph with established complete paths betwe
iAd Production Beginner's Guide
Collier, Ben
2012-01-01
This beginner's guide focuses on getting you through all the major learning points in a smooth, logical order. You'll also see how to avoid some common pitfalls. This book is for brands, advertisers and developers who want to create compelling, emotive, iAd advertisements that generate revenue and increase brand awareness. You don't need previous experience of creating adverts or apps for iPhone and iPad, as you'll be taken through the entire process to make motion-rich, beautiful ads.
Adscape: Harvesting and Analyzing Online Display Ads
Barford, Paul; Canadi, Igor; Krushevskaja, Darja; Ma, Qiang; Muthukrishnan, S.
2014-01-01
Over the past decade, advertising has emerged as the primary source of revenue for many web sites and apps. In this paper we report a first-of-its-kind study that seeks to broadly understand the features, mechanisms and dynamics of display advertising on the web - i.e., the Adscape. Our study takes the perspective of users who are the targets of display ads shown on web sites. We develop a scalable crawling capability that enables us to gather the details of display ads including creatives an...
Vehicular ad hoc network security and privacy
Lin, X
2015-01-01
Unlike any other book in this area, this book provides innovative solutions to security issues, making this book a must read for anyone working with or studying security measures. Vehicular Ad Hoc Network Security and Privacy mainly focuses on security and privacy issues related to vehicular communication systems. It begins with a comprehensive introduction to vehicular ad hoc network and its unique security threats and privacy concerns and then illustrates how to address those challenges in highly dynamic and large size wireless network environments from multiple perspectives. This book is richly illustrated with detailed designs and results for approaching security and privacy threats.
The Stylistic Analysis of car ads languages
Institute of Scientific and Technical Information of China (English)
张伟苹
2014-01-01
Automotive advertising language is mix of phonetics, vocabulary, rhetoric, syntax, and discourse language etc., and owning a strong promotional effect which can functioned as a bridge between language expression and promotion system for es-sential products and consumers. As a kind of the commercial advertising, car advertising with its own unique language features not only for product considerably, but also enriches the advertising language. In order to analysis the car ads, this article draws at-tention from the aspects of the phonetics, vocabulary, rhetoric and syntax features, and aims to get a further and better analysis or understanding of the car ads Languages.
AD-1 with research pilot Richard E. Gray
1982-01-01
1981/1982. Richard E. Gray was born March 11, 1945 in Newport News, Virginia; he died on November 8, 1982 at Edwards, California, in a T-37 spin accident. The Ames-Dryden-1 (AD-1) aircraft was designed to investigate the concept of an oblique (pivoting) wing. The wing could be rotated on its center pivot, so that it could be set at its most efficient angle for the speed at which the aircraft was flying. NASA Ames Research Center Aeronautical Engineer Robert T. Jones conceived the idea of an oblique wing. His wind tunnel studies at Ames (Moffett Field, CA) indicated that an oblique wing design on a supersonic transport might achieve twice the fuel economy of an aircraft with conventional wings. The oblique wing on the AD-1 pivoted about the fuselage, remaining perpendicular to it during slow flight and rotating to angles of up to 60 degrees as aircraft speed increased. Analytical and wind tunnel studiesthat Jones conducted at Ames indicated that a transport-sized oblique-wing aircraft flying at speeds of up to Mach 1.4 (1.4 times the speed of sound) would have substantially better aerodynamic performance than aircraft with conventional wings. The AD-1 structure allowed the project to complete all of its technical objectives. The type of low-speed, low-cost vehicle - as expected - exhibited aeroelastic and pitch-roll-coupling effects that contributed to poor handling at sweep angles above 45 degrees. The fiberglass structure limited the wing stiffness that would have improved the handling qualities. Thus, after completion of the AD-1 project, there was still a need for a transonic oblique-wing research aircraft to assess the effects of compressibility, evaluate a more representative structure, and analyze flight performance at transonic speeds (those on either side of the speed of sound). The aircraft was delivered to the Dryden Flight Research Center, Edwards, CA, in March 1979 and its first flight was on December 21, 1979. Piloting the aircraft on that flight, as well
Institute of Scientific and Technical Information of China (English)
ZHANG Ye; Michael G. Irwin; LI Rui; CHEN Zhiwu; Tak-Ming Wong
2009-01-01
Background Preconditioning with remifentanil confers cardioprotection. Since Ca2+ overload is a precipitating factor of injury, we determined the effects of remefentanil on intracellular Ca2+ ([Ca2+]I) and its transients induced by electrical stimulation and caffeine, which reflects Ca2+ handling by Ca2+ handling proteins, in rat ventricular myocytes. Methods Freshly isolated adult male Sprague-Dawley rat myocytes were loaded with Fura-2/AM and [Ca]I was determined by spectrofluorometry. Remifentanil at 0.1-1000 μg/L was administered. Ten minutes after administration, either 0.2 Hz electrical stimulation was applied or 10 mmol/L caffeine was added. The [Ca2+]I, and the amplitude, time resting and 50% decay (t50) of both transients induced by electrical stimulation (E[Ca2+]I) and caffeine (C[Ca2+]I) were determined.Results Remifentanil (0.1-1000.0 μg/L) decreased the [Ca2+]I in a dose-dependent manner. It also decreased the amplitude of both transients dose-dependently. Furthermore, it increased the time to peak and t50 of both transients dose-dependently.Conclusion Remifentanil reduced the [Ca2+]I and suppressed the transients induced by electrical stimulation and caffeine in rat ventricular myocytes.
施磷肥对土壤中Ca^2＋吸持特征的影响%Effects of P Fertilization on the Ca^2+ Retention Characteristics in Soil
Institute of Scientific and Technical Information of China (English)
张大庚; 贺云龙; 栗杰; 依艳丽; 刘敏霞
2012-01-01
以辽宁省典型耕地土壤（棕壤和褐土）为研究对象,在研究土壤Ca2＋释放和Ca2＋等温吸持的基础上,系统研究不同pH条件下施磷肥对土壤Ca2＋吸持特征的影响。结果表明：棕壤和褐土中Ca2＋在2h左右为快速释放阶段,Ca2＋的释放量为褐土〉棕壤,而释放率为褐土〈棕壤。褐土对Ca2＋的吸持能力要大于棕壤;随电解质溶液pH值增加,磷肥的添加明显增加了Ca2＋的沉淀量;当加磷肥量相同时,加入PO34-后Ca2＋的沉淀量高于HPO24-;随加磷肥量增加,加入PO34-或HPO24-与Ca2＋形成的沉淀量均增加。随着电解质溶液pH值的升高,土壤对Ca2＋的吸持量增加,但与对照相比增加的倍数下降。pH值对土壤吸持Ca2＋的影响为棕壤〉褐土,添加HPO24-〉添加PO34-。%Typical cultivation soils of brown earth and cinnamon soil were taken as the research objects,Liaoning province.On the basis of the research of Ca2+ releasing and the isothermal adsorption,the paper studied the effects of P fertilization on Ca2+ absorption characteristics in soil under different pH.The results show that Ca2+ releasing was quick in 2 h in brown earth and cinnamon soil.Ca2+ releasing quantity was brown earth cinnamon soil and releasing rate was brown earth cinnamon soil.The adsorption ability of Ca2+ was brown earth cinnamon soil.With the increase of the solution pH value,the phosphorus added to solution significantly increased the amount of precipitation Ca2+.When the phosphorus added to solution was same in quantity,precipitation weight generating between PO3-4 and Ca2+ was higher than that generating between HPO2-4 and Ca2+.With the amount of phosphorus added to solution increasing,precipitation weight generating between PO3-4 or HPO2-4and Ca2+ increased.With the rise of electrolyte solution pH value,Ca2+ adsorption to soil increased,but the percentage increased in decline comparing with the control.The effect of pH value on the adsorption Ca2
Effect of CaO from Mineral and Pure Oxide on Nano structure Cordierite
International Nuclear Information System (INIS)
Cordierite was synthesized via glass-route using mineral and pure oxide material. Kaolin, talc, dolomite, magnesia, alumina, silica, and calcium oxide were mixed and melted at 1540 degree Celsius for 4 h. CaO from mineral and pure oxide was added in order to investigate the properties of each material in cordierite system. Sample was characterized using XRD analysis, dilatometer testing and SEM. XRD result shows that when 5 wt % CaO from mineral (C5 Min) was added and sintered at 900 degree Celsius, α-cordierite exist as major phase and anorthite as a minor phase. While for a sample consists of 5 wt % CaO from pure oxide (C5 Ox), α-cordierite was present as major phases α-cordierite and anorthite as minor phases. Crystallite sizes of each material were in nano range and crystallite size of C5 Ox was less than C5 Min. (author)
Y-system for form factors at strong coupling in AdS5 and with multi-operator insertions in AdS3
Gao, Zhiquan; Yang, Gang
2013-06-01
We study form factors in {N}=4 SYM at strong coupling in general kinematics and with multi-operator insertions by using gauge/string duality and integrability techniques. This generalizes the AdS3 results of Maldacena and Zhiboedov in two non-trivial aspects. The first generalization to AdS5 space was motivated by its potential connection to strong coupling Higgs-to-three-gluons amplitudes in QCD which was observed recently at weak coupling. The second generalization to multi-operator insertions was motivated as a step towards applying on-shell techniques to compute correlation functions at strong coupling. In this picture, each operator is associated to a monodromy condition on the cusp solutions. We construct Y-systems for both cases. The Y -functions are related to the spacetime (cross) ratios. Their WKB approximations based on a rational function P ( z) are also studied. We focus on the short operators, while the prescription is hopefully also applicable for more general operators.
Jansen, E. P. W. A.; Nieuwenhuis, A. F. M.
2013-01-01
Study success rates in higher education were already described in an article in Pedagogische Studien in 1959. Professor A.D. de Groot, internationally well-known by his research on Thought and choice in chess, analysed the success rate figures provided by Statistics Netherlands. Based on the differe
Fuel performance evaluation for ADS MYRRHA
International Nuclear Information System (INIS)
MYRRHA is an Accelerator Driven System (ADS) under development at Mol in Belgium and aiming to serve as a basis for the European experimental ADS to provide protons and neutrons for various applications. It consists of a proton accelerator delivering a 350 MeV*5 mA proton beam to a liquid Pb-Bi spallation target that in turn couples to a Pb-Bi cooled, subcritical fast core. A preliminary design of the experimental fuel rods and analysis of their performance under typical ADS conditions is a first step of the fuel development program. Different designs are to be studied and different kinds of fuels are expected to be tested. In the current design, (U,Pu)O2 MOX fuel with the enrichment of 20-30 wt.% of Pu is considered to be a basis of the subcritical core, whereas different sorts of experimental fuel rods should be tested in the experimental channels to study minor actinides and low-lived fission products transmutation. In a later phase, a part of the MOX fuel in the subcritical core will be replaced with non-uranium fuels with transuranium elements. In the present report some result of modelling of the behaviour of two experimental rods (one with MOX and another with IMF) in the hottest fuel assembly of the ADS MYRRHA - are presented. (author)
Adding Users to the Website Design Process
Tomeo, Megan L.
2012-01-01
Alden Library began redesigning its website over a year ago. Throughout the redesign process the students, faculty, and staff that make up the user base were added to the conversation by utilizing several usability test methods. This article focuses on the usability testing conducted at Alden Library and delves into future usability testing, which…
Value-Added Modeling in Physical Education
Hushman, Glenn; Hushman, Carolyn
2015-01-01
The educational reform movement in the United States has resulted in a variety of states moving toward a system of value-added modeling (VAM) to measure a teacher's contribution to student achievement. Recently, many states have begun using VAM scores as part of a larger system to evaluate teacher performance. In the past decade, only "core…
Double Thermalization via AdS/CFT
Ali-Akbari, M; Kishani-Farahani, A; Shafie, N
2016-01-01
We exploit the AdS/CFT correspondence to investigate thermalization in an N=2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under variation of an external electric field leading to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS_5 X S^5 background. In the dual gravity theory, due to a time-dependent electric field an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe that two apparent horizons form on the brane. On the gauge theory side, ...
Added value: The differences that count
Directory of Open Access Journals (Sweden)
Dominique Bouchet
2012-08-01
Full Text Available Clinging to a simplistic conceptualization of the concept of added value might impair our capability to develop insights to what really matters today when companies seek to make differences within the global market. Today it is more necessary than ever to take into account the importance of language and culture as competitive factors.
Amiri-Sharifi, S.; Ali-Akbari, M.; Kishani-Farahani, A.; Shafie, N.
2016-08-01
We exploit the AdS/CFT correspondence to investigate thermalization in an N = 2 strongly coupled gauge theory including massless fundamental matter (quark). More precisely, we consider the response of a zero temperature state of the gauge theory under influence of an external electric field which leads to a time-dependent current. The holographic dual of the above set-up is given by introducing a time-dependent electric field on the probe D7-brane embedded in an AdS5 ×S5 background. In the dual gravity theory an apparent horizon forms on the brane which, according to AdS/CFT dictionary, is the counterpart of the thermalization process in the gauge theory side. We classify different functions for time-dependent electric field and study their effect on the apparent horizon formation. In the case of pulse functions, where the electric field varies from zero to zero, apart from non-equilibrium phase, we observe the formation of two separate apparent horizons on the brane. This means that the state of the gauge theory experiences two different temperature regimes during its time evolution.
Context discovery in ad-hoc networks
Liu, Fei
2011-01-01
Mobile ad-hoc networks (MANETs) are more and more present in our daily life. Such networks are often composed of mobile and battery-supplied devices, like laptops and PDAs. With no requirement for infrastructure support, MANETs can be used as temporary networks, such as for conference and office env
The Added Value of Business Models
Vliet, Harry van
2014-01-01
An overview of innovations in a particular area, for example retail developments in the fashion sector (Van Vliet, 2014), and a subsequent discussion about the probability as to whether these innovations will realise a ‘breakthrough’, has to be supplemented with the question of what the added value
Localization in Ad-Hoc Sensor Networks
Keijzer, de A.
2003-01-01
In many applications, like tracking persons, the position of sensor nodes is important. This report describes existing research in localization. Using these existing methods a localization method for ad-hoc sensor networks is presented. Simulation results are discussed and suggestions for implementa
AdS/CFT correspondence and supersymmetry
International Nuclear Information System (INIS)
We use the group-theoretic interpretation of the AdS/CFT correspondence which we proposed earlier in order to lift intertwining operators acting between boundary conformal representations to intertwining operators acting between bulk conformal representations. Further, we present the classification of the positive energy (lowest weight) unitary irreducible representations of the D=6 superconformal algebras osp(8*/2N). (author)
CERN Enters the Second Year AD
2001-01-01
2001 is the year that physics at CERN's new Antiproton Decelerator (AD) really gets up to speed. Changes to the AD since 2000 mean that this year the three experiments, ASACUSA, ATHENA, and ATRAP have had more intense antiproton beams to work with since physics started on 7 May. CERN's Antiproton Decelerator - major improvements for 2001. The AD is a unique machine. Its job is to decelerate not accelerate particle beams, and it has to handle beam energies that vary by an unprecedented factor of 35 from injection to ejection. Since the machine was designed to operate at fixed energy in its first incarnation as a collector of antiprotons for CERN's 1980s proton antiproton collider, this factor of 35 presented a big challenge to the AD team. The team's design goal was to hang onto a quarter of the injected antiprotons through their vertiginous fall in energy, and to repeat the deceleration cycle once per minute. Improvements to the machine over the winter shutdown and through the first four weeks of 2001 run...
ENEA presenta sistema ADS per trattamento scorie
2002-01-01
"Arriva il sistema Ads (Accelerator driven system) per il trattamento dei rifiuti radioattivi. Lo studio di fattibilita' per l' innovativa tecnologia, realizzato da un gruppo di lavoro congiunto Enea, Cea, Cern e Ansaldo, e' stato presentato oggi nel corso di un workshop presieduto dal premio Nobel per la fisica, Carlo Rubbia" (1/2 page).
Holzscheiter, M H
2014-01-01
After 7 years running the AD-4 Experiment at antiproton momentum of 502 MeV/c we have now assembled a complete data set and are preparing to combine all years into a single analysis of RBE vs. Depth for an antiproton beam stopping in water. We describe experimental challenges and computational issues which need to be resolved to achieve this final step.
DEFF Research Database (Denmark)
Stassis, C.; Zaretsky, J.; Misemer, D. K.;;
1983-01-01
A large single crystal of FCC Ca was grown and was used to study the lattice dynamics of this divalent metal by coherent inelastic neutron scattering. The phonon dispersion curves were measured, at room temperature, along the [ξ00], [ξξ0], [ξξξ], and [0ξ1] symmetry directions. The dispersion curves...... bear a striking resemblance to those of FCC Yb, which is also a divalent metal with an electronic band structure similar to that of Ca. In particular, the shear moduli c44 and (c11-c 12)/2 differ by a factor of 3.4, which implies that FCC Ca (like FCC Yb) is very anisotropic with regard...... to the propagation of elastic waves. The frequencies of the T1[ξξ0] branch for ξ between approximately 0.5 and 0.8 are slightly above the velocity-of-sound line determined from the low-frequency measurements. Since a similar effect has been observed in FCC Yb, it is natural to assume that the anomalous dispersion...
EVH Black Holes, AdS3 Throats and EVH/CFT Proposal
Sheikh-Jabbaria, M M
2011-01-01
Within class of generic black holes there are extremal black holes (with vanishing Hawking temperature T) and vanishing horizon area Ah, but with finite Ah/T ratio,the Extremal Vanishing Horizon (EVH) black holes. We study the near horizon limit of a four dimensional EVH black hole solution to a generic (gauged) Einstein-Maxwell dilaton theory and show that in the near horizon limit they develop a throat which is a pinching orbifold limit of AdS3. This is an extension of the well known result for extremal black holes the near horizon limit of which contains an AdS2 throat. We show that in the near EVH near horizon limit the pinching AdS3 factor turns to a pinching BTZ black hole and that this near horizon limit is indeed a decoupling limit. We argue that the pinching AdS3 or BTZ orbifold is resolved if the near horizon limit is accompanied by taking the 4d Newton constant G4 to zero such that the Bekenstein-Hawking entropy S = Ah/(4G4) remains finite. We propose that in this limit the near horizon EVH black h...
E.G. Smit; P.C. Neijens; R. Heath
2013-01-01
Building on previous research on the processing of newspaper ads, this comprehensive field study, with 26,556 newspaper readers and 290 unique advertisements, investigated the combined effects of position in the newspaper, ad characteristics and reader characteristics. The results show a differentia
Time-dependent flow from an AdS Schwarzschild black hole
International Nuclear Information System (INIS)
I discuss two examples of time-dependent flow which can be described in terms of an AdS Schwarzschild black hole via holography. The first example involves Bjorken hydrodynamics which should be applicable to the formation of the quark gluon plasma in heavy ion collisions. The second example is the cosmological evolution of our Universe
D-branes from Pure Spinor Superstring in AdS_5 x S^5 Background
Hanazawa, Sota
2016-01-01
We examine the surface term for the BRST transformation of the open pure spinor superstring in an AdS_5 x S^5 background. We find that the boundary condition to eliminate the surface term leads to a classification of possible configurations of 1/2 supersymmetric D-branes.
Ad Hoc Network Security Technology%Ad hoc网络安全技术简介
Institute of Scientific and Technical Information of China (English)
李俊; 李鑫; 黄红伟
2011-01-01
Ad hoc network is a kind of mobile network without fixed infrastructure;all nodes are composed of mobile host.As the mobility of the node leads to network topology changing quickly and node communication is based on wireless links,Ad hoc network is facing greater challenges more than cane network about security.In this paper,according to Ad hoe network security issues,we analysis common attacks in the Ad hoe network,focused on secure routing,key management and other key issues.%Ad hoc网络是一种没有有线基础设施支持的移动网络，网络中的节点均由移动主机构成。由于节点的移动性导致网络拓扑结构不断变化，节点通信完全依靠无线链路，相对于有线网络在安全性上面临更大的挑战。本文根据Ad hoc网络面临的安全问题，分析了Ad hoc网络中常见的攻击方式，并集中讨论了Ad hoc网络的安全路由、密钥管理等关键问题。
Phase transitions of magnetic AdS4 black holes with scalar hair
Hristov, K.; Toldo, C.; Vandoren, S.
2013-01-01
We determine the thermodynamic properties of a class of spherically symmetric and static black holes in AdS4 with magnetic charges and scalar hair. These black holes are solutions in four-dimensional N=2 gauged supergravity that can arise from 11-dimensional supergravity compactified on S7. At zero
Parametrization of cosets for AdS5xS5 superstring action
Siegel, W
2015-01-01
A formulation recently proposed [arXiv:1506.07706] as an alternative to the usual coset PSU(2,2|4)/USp(2,2)USp(4) for the superspace geometry of the Type IIB superstring on an AdS5xS5 background is shown to be a particular parametrization of this coset. Standard methods can then be applied.
Correction terms to Newton law due to induced gravity in AdS background
Ito, M
2003-01-01
We calculate small correction terms to gravitational potential on Randall-Sundrum brane with an induced Einstein term. The behaviors of the correction terms depend on the magnitudes of $AdS$ radius $k^{-1}$ and a characteristic length scale $\\l$ of model. We present the gravitational potential for arbitrary $k$ and $\\l$ at all distances.
Near horizon data and physical charges of extremal AdS black holes
Astefanesei, D.; Banerjee, N.; Dutta, S.
2011-01-01
We compute the physical charges and discuss the properties of a large class of five-dimensional extremal AdS black holes by using the near horizon data. Our examples include baryonic and electromagnetic black branes, as well as supersymmetric spinning black holes. In the presence of the gauge Chern–
F-string Solution in AdS4 X CP3 PP-wave Background
Banerjee, Gourav
2016-01-01
We present supergravity solution for F-string in pp wave background obtained from AdS4 X CP3 with zero flat directions.The classical solution is shown to break all space-time supersymmetries. We explicitly write down the standard as well as supernumerary Killing spinors both for the background and F-string solution.
Entropy of near-extremal black holes in AdS_5
V. Balasubramanian; J. de Boer; V. Jejjala; J. Simón
2008-01-01
We construct the microstates of near-extremal black holes in AdS_5 x S^5 as gases of defects distributed in heavy BPS operators in the dual SU(N) Yang-Mills theory. These defects describe open strings on spherical D3-branes in the S^5, and we show that they dominate the entropy by directly enumerati
String in AdS black hole: A thermo field dynamic approach
Cantcheff, M. Botta; Gadelha, Alexandre L.; Marchioro, Dáfni F. Z.; Nedel, Daniel Luiz
2012-10-01
Based on Maldacena’s description of an eternal anti-de Sitter (AdS) black hole, we reassess the thermo field dynamics (TFD) formalism in the context of the AdS/CFT correspondence. The model studied here involves the maximally extended AdS-Schwarschild solution and two (noninteracting) copies of the conformal field theory (CFT) associated to the global AdS spacetime, along with an extension of the string by imposing natural gluing conditions in the horizon. We show that the gluing conditions in the horizon define a string boundary state which is identified with the TFD thermal vacuum, globally defined in the Kruskal extension of the AdS black hole. We emphasize the connection of this picture with unitary SU(1,1) TFD formulation, and we show that information about the bulk and the conformal boundary is present in the SU(1,1) parameters. Using the unitary SU(1,1) TFD formulation, a canonical prescription for calculating the world sheet real time thermal Green’s function is made, and the entropy associated with the entanglement of the two CFT’s is calculated.
Thermal String Vacuum in Black-Hole AdS Spacetime
Graça, E L
2005-01-01
In this letter we propose a new ansatz for the thermal string in the TFD formulation. From it, we derive the thermal vacuum for the closed bosonic string and calculate the thermal partition function in the blackhole $AdS$ background in the first order of the perturbative quantization.
On Critical Massive (Super)Gravity in adS3
Bergshoeff, Eric A.; Hohm, Olaf; Rosseel, Jan; Sezgin, Ergin; Townsend, Paul K.
2011-01-01
We review the status of three-dimensional “general massive gravity” (GMG) in its linearization about an anti-de Sitter (adS) vacuum, focusing on critical points in parameter space that yield generalizations of “chiral gravity”. We then show how these results extend to N = 1 super-GMG, expanded about
On Critical Massive (Super)Gravity in adS(3)
Bergshoeff, Eric A.; Hohm, Olaf; Rosseel, Jan; Sezgin, Ergin; Townsend, Paul K.; Aldaya,; Barcelo, C; Jaramillo, JL
2011-01-01
We review the status of three-dimensional "general massive gravity" (GMG) in its linearization about an anti-de Sitter (adS) vacuum, focusing on critical points in parameter space that yield generalizations of "chiral gravity". We then show how these results extend to,N = 1 super-GMG, expanded about
The Complexity of Identifying Ryu-Takayanagi Surfaces in AdS3/CFT2
Bao, Ning
2016-01-01
We present a constructive algorithm for the determination of Ryu-Takayanagi surfaces in AdS3/CFT2 which exploits previously noted connections between holographic entanglement entropy and max-flow/min-cut. We then characterize its complexity as a polynomial time algorithm.
The $AdS_{5}xS^(5)$ fermionic model
Abdalla, Elcio
2013-01-01
We consider the $AdS_{5}xS^(5)$ integrable model. As it turns out, relying on well known arguments, we claim that the conformally invariant fermionic model is solvable, the resulting solution given in terms of two current algebras realizations.
Magnetic charges in the AdS(4) superalgebra osp(4 vertical bar 2)
Dibitetto, Giuseppe; Klemm, Dietmar
2010-01-01
We discuss the issue of how to include magnetic charges in the AdS(4) superalgebra osp(4 vertical bar 2). It is shown that the usual way of introducing a pseudoscalar central charge on the right hand side of the basic anticommutator does not work, because this breaks SO(2, 3) covariance. We propose
An alternative perspective to observe the critical phenomena of dilaton AdS black holes
Mo, Jie-Xiong
2016-01-01
The critical phenomena of dilaton AdS black holes are probed from a totally different perspective other than the $P-v$ criticality and the $q-U$ criticality discussed in the former literature. We investigate not only the two point correlation function but also the entanglement entropy of dilaton AdS black holes. We achieve this goal by solving the equation of motion constrained by the boundary condition numerically and we concentrate on $\\delta L$ and $\\delta S$ which have been regularized by subtracting the terms in pure AdS with the same boundary region. For both the two point correlation function and the entanglement entropy, we consider $4\\times2\\times2=16$ cases due to different choices of parameters. The van der Waals like behavior can be clearly witnessed from all the $T-\\delta L$ ($T-\\delta S$) graphs for $q
Holographic Renormalization for z=2 Lifshitz Space-Times from AdS
Chemissany, Wissam; Hartong, Jelle; Rollier, Blaise
2012-01-01
Lifshitz space-times with critical exponent z=2 can be obtained by dimensional reduction of Schroedinger space-times with critical exponent z=0. The latter space-times are asymptotically AdS solutions of AdS gravity coupled to an axion-dilaton system and can be uplifted to solutions of type IIB supergravity. This basic observation is used to perform holographic renormalization for 4-dimensional asymptotically z=2 locally Lifshitz space-times by Scherk-Schwarz dimensional reduction of the corresponding problem of holographic renormalization for 5-dimensional asymptotically locally AdS space-times coupled to an axion-dilaton system. We can thus define and characterize a 4-dimensional asymptotically locally z=2 Lifshitz space-time in terms of 5-dimensional AdS boundary data. In this setup the 4-dimensional structure of the Fefferman-Graham expansion and the structure of the counterterm action, including the scale anomaly, will be discussed. We find that for asymptotically locally z=2 Lifshitz space-times obtaine...
Warped AdS near-horizon geometry of completely localized intersections of M5-branes
International Nuclear Information System (INIS)
We study a Hanany-Witten set-up relevant to N = 2 superconformal field theories. We find the exact near-horizon solution for this 11-dimensional system which involves intersecting M5-branes. The metric describes a warped product of AdS5 with a manifold with SU(2)xU(1) isometry. (author)
Designing added functions in engineered cementitious composites
Yang, En-Hua
In this dissertation, a new and systematic material design approach is developed for ECC with added functions through material microstructures linkage to composite macroscopic behavior. The thesis research embodies theoretical development by building on previous ECC micromechanical models, and experimental investigations into three specific new versions of ECC with added functions aimed at addressing societal demands of our built infrastructure. Specifically, the theoretical study includes three important ECC modeling elements: Steady-state crack propagation analyses and simulation, predictive accuracy of the fiber bridging constitutive model, and development of the rate-dependent strain-hardening criteria. The first element establishes the steady-state cracking criterion as a fundamental requirement for multiple cracking behavior in brittle matrix composites. The second element improves the accuracy of crack-width prediction in ECC. The third element establishes the micromechanics basis for impact-resistant ECC design. Three new ECCs with added functions were developed and experimentally verified in this thesis research through the enhanced theoretical framework. A green ECC incorporating a large volume of industrial waste was demonstrated to possess reduced crack width and drying shrinkage. The self-healing ECC designed with tight crack width was demonstrated to recover transport and mechanical properties after microcrack damage when exposed to wet and dry cycles. The impact-resistant ECC was demonstrated to retain tensile ductility with increased strength under moderately high strain-rate loading. These new versions of ECC with added functions are expected to contribute greatly to enhancing the sustainability, durability, and safety of civil infrastructure built with ECC. This research establishes the effectiveness of micromechanics-based design and material ingredient tailoring for ECC with added new attributes but without losing its basic tensile ductile
Black hole formation in AdS and thermalization on the boundary
International Nuclear Information System (INIS)
We investigate black hole formation by a spherically collapsing thin shell of matter in AdS space. This process has been suggested to have a holographic interpretation as thermalization of the CFT on the boundary of the AdS space. The AdS/CFT duality relates the shell in the bulk to an off-equilibrium state of the boundary theory which evolves towards a thermal equilibrium when the shell collapses to a black hole. We use 2-point functions to obtain information about the spectrum of excitations in the off-equilibrium state, and discuss how it characterizes the approach towards thermal equilibrium. The full holographic interpretation of the gravitational collapse would require a kinetic theory of the CFT at strong coupling. We speculate that the kinetic equations should be interpreted as a holographic dual of the equation of motion of the collapsing shell. (author)
Black Hole Formation in AdS Einstein-Gauss-Bonnet Gravity
Deppe, Nils; Frey, Andrew R; Kunstatter, Gabor
2016-01-01
AdS spacetime has been shown numerically to be unstable against a large class of arbitrarily small perturbations. In arXiv:1410.1869, the authors presented a preliminary study of the effects on stability of changing the local dynamics by adding a Gauss-Bonnet term to the Einstein action. Here we provide further details as well as new results with improved numerical methods. In particular, we elucidate new structure in Choptuik scaling plots. We also provide evidence of chaotic behavior at the transition between immediate horizon formation and horizon formation after the matter pulse reflects from the AdS conformal boundary. Finally, we present data suggesting the formation of naked singularities in spacetimes with ADM mass below the algebraic bound for black hole formation.
Holographic Thermalization, Stability of AdS, and the FPU Paradox
Balasubramanian, Venkat; Green, Stephen R; Lehner, Luis; Liebling, Steven L
2014-01-01
For a real massless scalar field in general relativity with a negative cosmological constant, we uncover a large class of spherically symmetric initial conditions that are close to AdS, but whose numerical evolution does not result in black hole formation. According to the AdS/CFT dictionary, these bulk solutions are dual to states of a strongly interacting boundary CFT that fail to thermalize at late times. Furthermore, as these states are not stationary, they define dynamical CFT configurations that do not equilibrate. We develop a two-timescale perturbative formalism that captures both direct and inverse cascades of energy and agrees with our fully nonlinear evolutions in the appropriate regime. We also show that this formalism admits a large class of quasi-periodic solutions. Finally, we demonstrate a striking parallel between the dynamics of AdS and the classic Fermi-Pasta-Ulam-Tsingou problem.
Effects of dark energy on P–V criticality of charged AdS black holes
International Nuclear Information System (INIS)
In this Letter, we investigate the effects of dark energy on P–V criticality of charged AdS black holes by considering the case of the RN-AdS black holes surrounded by quintessence. By treating the cosmological constant as thermodynamic pressure, we study its thermodynamics in the extended phase space. It is shown that quintessence dark energy does not affect the existence of small/large black hole phase transition. For the case ωq=−2/3 we derive analytic expressions of critical physical quantities, while for cases ωq≠−2/3 we appeal to numerical method for help. It is shown that quintessence dark energy affects the critical physical quantities near the critical point. Critical exponents are also calculated. They are exactly the same as those obtained before for arbitrary other AdS black holes, which implies that quintessence dark energy does not change the critical exponents
Hairy Black Holes in AdS$_5\\times S^5$
Markeviciute, J
2016-01-01
We use numerical methods to exhaustively study a novel family of hairy black hole solutions in AdS$_5$. These solutions can be uplifted to solutions of type IIB supergravity with AdS$_5\\times S^5$ asymptotics and are thus expected to play an important role in our understanding of AdS/CFT. We find an intricate phase diagram, with the aforementioned family of hairy black hole solutions branching from the Reissner-Nordstr\\"om black hole at the onset of the superradiance instability. We analyse black holes with spherical and planar horizon topology and explain how they connect in the phase diagram. Finally, we detail their global and local thermodynamic stability across several ensembles.
Fine tuning of cytosolic Ca 2+ oscillations
Dupont, Geneviève; Combettes, Laurent
2016-01-01
Ca 2+ oscillations, a widespread mode of cell signaling, were reported in non-excitable cells for the first time more than 25 years ago. Their fundamental mechanism, based on the periodic Ca 2+ exchange between the endoplasmic reticulum and the cytoplasm, has been well characterized. However, how the kinetics of cytosolic Ca 2+ changes are related to the extent of a physiological response remains poorly understood. Here, we review data suggesting that the downstream targets of Ca 2+ are controlled not only by the frequency of Ca 2+ oscillations but also by the detailed characteristics of the oscillations, such as their duration, shape, or baseline level. Involvement of non-endoplasmic reticulum Ca 2+ stores, mainly mitochondria and the extracellular medium, participates in this fine tuning of Ca 2+ oscillations. The main characteristics of the Ca 2+ exchange fluxes with these compartments are also reviewed. PMID:27630768
[Effect of polycarbophil Ca on IBS].
Mine, Tetsuya
2006-08-01
In this chapter, I mentioned the effect of polycarbophil Ca on IBS. IBS is classified into 3 types; diarrhea type, constipation type and combined type. Polycarbophil Ca is effective for all types of IBS.
CA-CA互操作研究%Research of CA-CA Interoperability
Institute of Scientific and Technical Information of China (English)
沈士根; 叶培松; 陈宝明
2005-01-01
文章介绍了国际上CA-CA之间实现互操作的信任模式,然后根据中国目前的PKI实际情况,提出了以桥CA为全局模式,局部可采用严格层次信任模式来实现各CA之间的互操作.
International Nuclear Information System (INIS)
Calcium influx drives two opposing voltage-activated calcium channel (CaV) self-modulatory processes: calcium-dependent inactivation (CDI) and calcium-dependent facilitation (CDF). Specific Ca2+/calmodulin (Ca2+/CaM) lobes produce CDI and CDF through interactions with the CaVα1 subunit IQ domain. Curiously, Ca2+/CaM lobe modulation polarity appears inverted between CaV1s and CaV2s. Here, we present crystal structures of CaV2.1, CaV2.2, and CaV2.3 Ca2+/CaM-IQ domain complexes. All display binding orientations opposite to CaV1.2 with a physical reversal of the CaM lobe positions relative to the IQ α-helix. Titration calorimetry reveals lobe competition for a high-affinity site common to CaV1 and CaV2 IQ domains that is occupied by the CDI lobe in the structures. Electrophysiological experiments demonstrate that the N-terminal CaV2 Ca2+/C-lobe anchors affect CDF. Together, the data unveil the remarkable structural plasticity at the heart of CaV feedback modulation and indicate that CaV1 and CaV2 IQ domains bear a dedicated CDF site that exchanges Ca2+/CaM lobe occupants
Evaporation of large black holes in AdS: coupling to the evaporon
International Nuclear Information System (INIS)
Large black holes in an asymptotically AdS spacetime have a dual description in terms of approximately thermal states in the boundary CFT. The reflecting boundary conditions of AdS prevent such black holes from evaporating completely. On the other hand, the formulation of the information paradox becomes more stringent when a black hole is allowed to evaporate. In order to address the information loss problem from the AdS/CFT perspective we then need the boundary to become partially absorptive. We present a simple model that produces the necessary changes on the boundary by coupling a bulk scalar field to the evaporon, an external field propagating in one extra spatial dimension. The interaction is localized at the boundary of AdS and leads to partial transmission into the additional space. The transmission coefficient is computed in the planar limit and perturbatively in the coupling constant. Evaporation of the large black hole corresponds to cooling down the CFT by transferring energy to an external sector.
Euclidean Wilson loops and minimal area surfaces in lorentzian AdS 3
Irrgang, Andrew; Kruczenski, Martin
2015-12-01
The AdS/CFT correspondence relates Wilson loops in N=4 SYM theory to minimal area surfaces in AdS 5 × S 5 space. If the Wilson loop is Euclidean and confined to a plane ( t, x) then the dual surface is Euclidean and lives in Lorentzian AdS 3 ⊂ AdS 5. In this paper we study such minimal area surfaces generalizing previous results obtained in the Euclidean case. Since the surfaces we consider have the topology of a disk, the holonomy of the flat current vanishes which is equivalent to the condition that a certain boundary Schrödinger equation has all its solutions anti-periodic. If the potential for that Schrödinger equation is found then reconstructing the surface and finding the area become simpler. In particular we write a formula for the Area in terms of the Schwarzian derivative of the contour. Finally an infinite parameter family of analytical solutions using Riemann Theta functions is described. In this case, both the area and the shape of the surface are given analytically and used to check the previous results.
String in AdS Black Hole: A Thermo Field Dynamic Approach
Cantcheff, M Botta; Marchioro, Dafni F Z; Nedel, Daniel Luiz
2012-01-01
Based on Maldacena's description of an eternal AdS-black hole, we reassess the Thermo Field Dynamics (TFD) formalism in the context of the AdS/CFT correspondence. The model studied here involves the maximally extended AdS-Schwarschild solution and two (non-interacting) copies of the CFT associated to the global AdS spacetime, along with an extension of the string by imposing natural gluing conditions in the horizon. We show that the gluing conditions in the horizon define a string boundary state which is identified with the TFD thermal vacuum, globally defined in the Kruskal extension of the AdS black hole. We emphasize the connection of this picture with unitary SU(1,1) TFD formulation and we show that information about the bulk and the conformal boundary is present in the SU(1,1) parameters. Using the unitary SU(1,1) TFD formulation, a canonical prescription for calculating the worldsheet real time thermal Green's function is made and the entropy associated with the entanglement of the two CFT's is calculat...
Holographic Rényi entropy in AdS3/LCFT2 correspondence
International Nuclear Information System (INIS)
The recent study in AdS3/CFT2 correspondence shows that the tree level contribution and 1-loop correction of holographic Rényi entanglement entropy (HRE) exactly match the direct CFT computation in the large central charge limit. This allows the Rényi entanglement entropy to be a new window to study the AdS/CFT correspondence. In this paper we generalize the study of Rényi entanglement entropy in pure AdS3 gravity to the massive gravity theories at the critical points. For the cosmological topological massive gravity (CTMG), the dual conformal field theory (CFT) could be a chiral conformal field theory or a logarithmic conformal field theory (LCFT), depending on the asymptotic boundary conditions imposed. In both cases, by studying the short interval expansion of the Rényi entanglement entropy of two disjoint intervals with small cross ratio x, we find that the classical and 1-loop HRE are in exact match with the CFT results, up to order x6. To this order, the difference between the massless graviton and logarithmic mode can be seen clearly. Moreover, for the cosmological new massive gravity (CNMG) at critical point, which could be dual to a logarithmic CFT as well, we find the similar agreement in the CNMG/LCFT correspondence. Furthermore we read the 2-loop correction of graviton and logarithmic mode to HRE from CFT computation. It has distinct feature from the one in pure AdS3 gravity
Institute of Scientific and Technical Information of China (English)
CHAI Li-yuan; XIAO Hai-juan; WANG Yun-yan; PEI Fei; SHU Yu-de; ZHANG Jin-long
2009-01-01
The effects of Na+ and Ca2+ in the purified water on the conductivity of zinc electrolyte and the current efficiency of zinc electrolysis were studied by the alternating current bridge method and the simulated electrolysis experiments, and the water quality index of reused water was established. The results show that the conductivity of the solution and the current efficiency decrease as these two kinds of positive ions are added in the electrolyte. The effect of Ca2+ is much more remarkable than that of Na+. ρ(Na+)≤ 8 g/L and ρ(Ca2+)≤20 mg/L are the quality indexes in the zinc electrolysis process and the concentrations of Na+ and Ca2+ in the purified water reused to the process should be less than the limited values, i.e. the water quality index of the purified water should be controlled by its reused amount.
Dielectrical and structural characterization of iron oxide added to hydroxyapatite
Indian Academy of Sciences (India)
C C Silva; F P Filho; M F P Graça; M A Valente; A S B Sombra
2008-08-01
In this work we report preparation, structural and dielectric analyses of iron oxide added in hydroxyapatite bioceramic (Ca10(PO4)6(OH)2 – HAP). Hydroxyapatite is the main mineral constituent of teeth and bones with excellent biocompatibility with hard and muscle tissues. The samples were prepared through a calcination procedure associated with dry high-energy ball milling process with different iron concentrations (1, 2.5 and 5 wt%). The dielectric analyses were made measuring the sample impedance in the frequency range 1 kHz–10 MHz, at room temperature. The relative permittivity of the ceramics, at 10 MHz, are between 7.13 ± 0.07 (1 wt%) and 6.20 ± 0.11 (5 wt%) while e″ are between 0.0795 ± 0.008 (1 wt%) and 0.067 ± 0.012 (5 wt%). These characteristics were related to the sample microstructures studied by X-ray diffraction and SEM.
ADS specific accelerator developments: Status in India
International Nuclear Information System (INIS)
Since India envisages the application as thorium–uranium breeder, the ADS must be operated with high beam power to maximize breeding potential. Since the thermalhydraulics issue in spallation target may restrict ~1 GeV proton beam current to ~10 mA on a single target module, an ADS core design is visualized with 3 or more spallation targets that would also help suppress the neutron flux peaking. With this assumption, the R&D objective is to realize a proton accelerator of 30 mA beam current (cw/average) within as short time as feasible. Of the two alternative accelerator types, cyclotron and LINAC, basic indigenous technological know-how, up to limited extent, exists for both
Noncommutative $q$-photon added coherent states
Dey, Sanjib
2016-01-01
We construct the photon added coherent states of a noncommutative harmonic oscillator associated to a $q$-deformed oscillator algebra. Various nonclassical properties of the corresponding system are explored, first, by studying two different types of higher order quadrature squeezing, namely the Hillery-type and the Hong--Mandel-type and, second, by testing the sub-Poissonian nature of photon statistics in higher order with the help of the correlation function and the Mandel parameter. By comparing our results with those of the usual harmonic oscillator, we notice that the quadratures and photon number distributions in noncommutative case are more squeezed for the same values of the parameters and, thus, the photon added coherent states of noncommutative harmonic oscillator may be more nonclassical in comparison to the ordinary harmonic oscillator.
Hubeny, Veronika E
2015-01-01
We give a brief review of the AdS/CFT correspondence, which posits the equivalence between a certain gravitational theory and a lower-dimensional non-gravitational one. This remarkable duality, formulated in 1997, has sparked a vigorous research program which has gained in breadth over the years, with applications to many aspects of theoretical (and even experimental) physics, not least to general relativity and quantum gravity. To put the AdS/CFT correspondence in historical context, we start by reviewing the relevant aspects of string theory (of which no prior knowledge is assumed). We then develop the statement of the correspondence, and explain how the two sides of the duality map into each other. Finally, we discuss the implications and applications of the correspondence, and indicate some of the current trends in this subject. The presentation attempts to convey the main concepts in a simple and self-contained manner, relegating supplementary remarks to footnotes.
Supporting Dynamic Ad hoc Collaboration Capabilities
International Nuclear Information System (INIS)
Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment
Supporting Dynamic Ad hoc Collaboration Capabilities
Energy Technology Data Exchange (ETDEWEB)
Agarwal, Deborah A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Berket, Karlo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2003-07-14
Modern HENP experiments such as CMS and Atlas involve as many as 2000 collaborators around the world. Collaborations this large will be unable to meet often enough to support working closely together. Many of the tools currently available for collaboration focus on heavy-weight applications such as videoconferencing tools. While these are important, there is a more basic need for tools that support connecting physicists to work together on an ad hoc or continuous basis. Tools that support the day-to-day connectivity and underlying needs of a group of collaborators are important for providing light-weight, non-intrusive, and flexible ways to work collaboratively. Some example tools include messaging, file-sharing, and shared plot viewers. An important component of the environment is a scalable underlying communication framework. In this paper we will describe our current progress on building a dynamic and ad hoc collaboration environment and our vision for its evolution into a HENP collaboration environment.
Flexible Authentication in Vehicular Ad hoc Networks
Caballero-Gil, P; Molina-Gil, J; Hernández-Goya, C
2010-01-01
A Vehicular Ad-Hoc Network (VANET) is a form of Mobile ad-hoc network, to provide communications among nearby vehicles and between vehicles and nearby fixed roadside equipment. The key operation in VANETs is the broadcast of messages. Consequently, the vehicles need to make sure that the information has been sent by an authentic node in the network. VANETs present unique challenges such as high node mobility, real-time constraints, scalability, gradual deployment and privacy. No existent technique addresses all these requirements. In particular, both inter-vehicle and vehicle-to-roadside wireless communications present different characteristics that should be taken into account when defining node authentication services. That is exactly what is done in this paper, where the features of inter-vehicle and vehicle-to-roadside communications are analyzed to propose differentiated services for node authentication, according to privacy and efficiency needs.
AD-1 with research pilot Richard E. Gray
1982-01-01
1981/1982. Richard E. Gray was born March 11, 1945 in Newport News, Virginia; he died on November 8, 1982 at Edwards, California, in a T-37 spin accident. The Ames-Dryden-1 (AD-1) aircraft was designed to investigate the concept of an oblique (pivoting) wing. The wing could be rotated on its center pivot, so that it could be set at its most efficient angle for the speed at which the aircraft was flying. NASA Ames Research Center Aeronautical Engineer Robert T. Jones conceived the idea of an oblique wing. His wind tunnel studies at Ames (Moffett Field, CA) indicated that an oblique wing design on a supersonic transport might achieve twice the fuel economy of an aircraft with conventional wings. The oblique wing on the AD-1 pivoted about the fuselage, remaining perpendicular to it during slow flight and rotating to angles of up to 60 degrees as aircraft speed increased. Analytical and wind tunnel studiesthat Jones conducted at Ames indicated that a transport-sized oblique-wing aircraft flying at speeds of up to Mach 1.4 (1.4 times the speed of sound) would have substantially better aerodynamic performance than aircraft with conventional wings. The AD-1 structure allowed the project to complete all of its technical objectives. The type of low-speed, low-cost vehicle - as expected - exhibited aeroelastic and pitch-roll-coupling effects that contributed to poor handling at sweep angles above 45 degrees. The fiberglass structure limited the wing stiffness that would have improved the handling qualities. Thus, after completion of the AD-1 project, there was still a need for a transonic oblique-wing research aircraft to assess the effects of compressibility, evaluate a more representative structure, and analyze flight performance at transonic speeds (those on either side of the speed of sound). The aircraft was delivered to the Dryden Flight Research Center, Edwards, CA, in March 1979 and its first flight was on December 21, 1979. Piloting the aircraft on that flight, as well
On AdS/CFT correspondence of EYM fields
Institute of Scientific and Technical Information of China (English)
无
2001-01-01
In the compactized Minkowski space, which is equivalent to the conformal space M4, we introduced a Lorentz metric d σ2 and a Yang-Mills field. Later, we proved that d σ2 and together satisfy the EYM (Einstein-Yang-Mills) equation. In this paper, it is proved that on M4 (which is the boundary of the anti-de-Sitter space AdS5) can be extended to be a Yang-Mills field on AdS5 such that Hua's metric ds2 on AdS5 together with satisfies the EYM equation on AdS5.
Cantrell, Sean
2015-01-01
Conformal deformations manifest in the AdS/CFT correspondence as boundary conditions on the AdS field. Heretofore, double-trace deformations have been the primary focus in this context. To better understand multitrace deformations, we revisit the relationship between the generating AdS partition function for a free bulk theory and the boundary CFT partition function subject to arbitrary conformal deformations. The procedure leads us to a formalism that constructs bulk fields from boundary operators. Using this formalism, we independently replicate the holographic RG flow narrative to go on to interpret the brane used to regulate the AdS theory as a renormalization scale. The scale-dependence of the dilatation spectrum of a boundary theory in the presence of general deformations can be thus understood on the AdS side using this formalism.
SILAGE CANE SUGAR ADDED WITH DRIED BREWER
W. J. R. Castro; A. M. Zanine; D.J. Ferreira
2015-01-01
The objective of this experiment was to evaluate the fermentative parameters and chemical composition of silage cane sugar added with residue dried brewery. The experimental design was completely randomized with four treatments and four replications: 100% cane sugar; 90% of cane sugar + 10% residue dried brewer; 80% of cane sugar + 20% residue dried brewer and 70% cane sugar + 30% dried brewer based on natural matter, composed silages. The sugar cane was chopped in a stationary machine with f...
ADS specific accelerator developments: Status in China
International Nuclear Information System (INIS)
A basic research programme of ADS was launched in 2000 under the support of the Ministry of Science and Technology, China. In this programme some key technologies are studied for an intense beam proton LINAC, including construction of an ECR proton source and a pulsed beam RFQ accelerator. Further, Chinese Academy of Sciences also gave a support to LINAC research in the field of medium-β superconducting cavity
The Great Collapse in Value Added Trade
Arne J Nagengast; Stehrer, Robert
2015-01-01
This paper studies the great collapse in value added trade using a structural decomposition analysis. We show that changes in vertical specialisation accounted for almost half of the great trade collapse, while the previous literature on gross trade has mainly focused on final expenditure, inventory adjustment and adverse credit supply conditions. The decline in international production sharing during the crisis may partially account for the observed decrease in global trade elasticities in r...
The Added-Worker Effect: A Reappraisal
Shelly J. Lundberg
1981-01-01
In this paper, the added worker effect is interpreted as a response to uncertain returns to labour supply offers by members of a household. A model of household labour supply is developed In which each member's current labour force status affects the job search and participation decisions of the other and thus the probabilities of observed transitions between the states of employment, unemployment, and non-participation. The determinants of actual household transitions are then investigated u...
Routing Security in Ad Hoc Wireless Networks
Pervaiz, Mohammad O.; Cardei, Mihaela; Wu, Jie
Wireless networks provide rapid, untethered access to information and computing, eliminating the barriers of distance, time, and location for many applications ranging from collaborative, distributed mobile computing to disaster recovery (such as fire, flood, earthquake), law enforcement (crowd control, search, and rescue), and military communications (command, control, surveillance, and reconnaissance). An ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration [11
Covariant anomalies and Hawking radiation from Kaluza–Klein AdS black holes
Indian Academy of Sciences (India)
Chuan-Yi Bai
2013-02-01
In this paper, Hawking radiation is studied from four-dimensional (4D) Kaluza–Klein (KK) AdS black holes via the method of anomaly cancellation. The {|bf KK-AdS} black hole considered is a non-extremal charged rotating solution in the theory of 4D gauged supergravity. Its Hawking fluxes of electric charge, angular momentum and energy momentum tensor are derived here. Our results support the common view that Hawking radiation is the quantum effect arising at the event horizon.
Geodesic Motions in AdS Soliton Background Space-time
Shi, Han-qing
2016-01-01
We study both massive and massless particle's geodesic motion in the background of general dimensional AdS-Sol space-time. We find that the massive particles oscillate along the radial direction, while massless particles experience one-time bouncing as they approach the "horizon" line of the soliton. Our results provide a direct way to understand the negative energy/masses leading to the AdS-Sol geometry. As a potential application, we extend the point particle to a 3-brane and fix the background as a 5+1 dimension AdS-Sol, thus obtain a very natural bouncing/cyclic cosmological model.
Entangled photon-added coherent states
Domínguez-Serna, Francisco A.; Mendieta-Jimenez, Francisco J.; Rojas, Fernando
2016-08-01
We study the degree of entanglement of arbitrary superpositions of m, n photon-added coherent states (PACS) {|{ψ }rangle } ∝ u {|{{α },m}rangle }{|{{β },n }rangle }+ v {|{{β },n}rangle }{|{{α },m}rangle } using the concurrence and obtain the general conditions for maximal entanglement. We show that photon addition process can be identified as an entanglement enhancer operation for superpositions of coherent states (SCS). Specifically for the known bipartite positive SCS: {|{ψ }rangle } ∝ {|{α }rangle }_a{|{-α }rangle }_b + {|{-α }rangle }_a{|{α }rangle }_b whose entanglement tends to zero for α → 0, can be maximal if al least one photon is added in a subsystem. A full family of maximally entangled PACS is also presented. We also analyzed the decoherence effects in the entangled PACS induced by a simple depolarizing channel . We find that robustness against depolarization is increased by adding photons to the coherent states of the superposition. We obtain the dependence of the critical depolarization p_{ {crit}} for null entanglement as a function of m,n, α and β.
ADS: The Next Generation Search Platform
Accomazzi, A.; Kurtz, M. J.; Henneken, E. A.; Chyla, R.; Luker, J.; Grant, C. S.; Thompson, D. M.; Holachek, A.; Dave, R.; Murray, S. S.
2015-04-01
Four years after the last LISA meeting, the NASA Astrophysics Data System (ADS) finds itself in the middle of major changes to the infrastructure and contents of its database. In this paper we highlight a number of features of great importance to librarians and discuss the additional functionality that we are currently developing. Our citation coverage has doubled since 2010 and now consists of over 10 million citations. We are normalizing the affiliation information in our records and we have started collecting and linking funding sources with papers in our system. At the same time, we are undergoing major technology changes in the ADS platform. We have rolled out and are now enhancing a new high-performance search engine capable of performing full-text as well as metadata searches using an intuitive query language. We are currently able to index acknowledgments, affiliations, citations, and funding sources. While this effort is still ongoing, some of its benefits are already available through the ADS Labs user interface and API at http://adslabs.org/adsabs/.
Data Confidentiality in Mobile Ad hoc Networks
Directory of Open Access Journals (Sweden)
Hamza Aldabbas
2012-03-01
Full Text Available Mobile ad hoc networks (MANETs are self-configuring infrastructure-less networks comprised of mobile nodes that communicate over wireless links without any central control on a peer-to-peer basis.These individual nodes act as routers to forward both their own data and also their neighbours’ data by sending and receiving packets to and from other nodes in the network. The relatively easy configuration and the quick deployment make ad hoc networks suitable the emergency situations (such as human or natural disasters and for military units in enemy territory. Securing data dissemination between these nodes in such networks, however, is a very challenging task. Exposing such information to anyone else other than the intended nodes could cause a privacy and confidentiality breach, particularly in military scenarios. In this paper we present a novel framework to enhance the privacy and data confidentiality in mobile ad hoc networks by attaching the originator policies to the messages as they are sent between nodes. We evaluate our framework using the Network Simulator (NS-2 to check whether the privacy and confidentiality of the originator are met. For this we implemented the Policy Enforcement Points (PEPs, as NS-2 agents that manage and enforce the policies attached to packets at every node in the MANET.
ADS: The Next Generation Search Platform
Accomazzi, Alberto; Henneken, Edwin A; Chyla, Roman; Luker, James; Grant, Carolyn S; Thompson, Donna M; Holachek, Alexandra; Dave, Rahul; Murray, Stephen S
2015-01-01
Four years after the last LISA meeting, the NASA Astrophysics Data System (ADS) finds itself in the middle of major changes to the infrastructure and contents of its database. In this paper we highlight a number of features of great importance to librarians and discuss the additional functionality that we are currently developing. Starting in 2011, the ADS started to systematically collect, parse and index full-text documents for all the major publications in Physics and Astronomy as well as many smaller Astronomy journals and arXiv e-prints, for a total of over 3.5 million papers. Our citation coverage has doubled since 2010 and now consists of over 70 million citations. We are normalizing the affiliation information in our records and, in collaboration with the CfA library and NASA, we have started collecting and linking funding sources with papers in our system. At the same time, we are undergoing major technology changes in the ADS platform which affect all aspects of the system and its operations. We hav...
Drag cancellation by added-mass pumping
Giorgio-Serchi, F
2016-01-01
A submerged body subject to a sudden shape-change experiences large forces due to the variation of added-mass energy. While this phenomenon has been studied for single actuation events, application to sustained propulsion requires studying \\textit{periodic} shape-change. We do so in this work by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. We develop an analytical model to investigate the relationship between added-mass variation and viscous damping and demonstrate its range of application with fully coupled fluid-solid Navier-Stokes simulations at large Stokes number. Our results demonstrate that the recovery of added-mass kinetic energy can be used to completely cancel the viscous damping of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius $r_0$. A quasi-linear relationship is found to link the terminal amplitude of the oscillations $X$, to the extent of size change $a$, wit...
Ad Serving Using a Compact Allocation Plan
Chen, Peiji; Mandalapu, Srinath; Nagarajan, Chandrashekhar; Shanmugasundaram, Jayavel; Vassilvitskii, Sergei; Vee, Erik; Yu, Manfai; Zien, Jason
2012-01-01
A large fraction of online display advertising is sold via guaranteed contracts: a publisher guarantees to the advertiser a certain number of user visits satisfying the targeting predicates of the contract. The publisher is then tasked with solving the ad serving problem - given a user visit, which of the thousands of matching contracts should be displayed, so that by the expiration time every contract has obtained the requisite number of user visits. The challenges of the problem come from (1) the sheer size of the problem being solved, with tens of thousands of contracts and billions of user visits, (2) the unpredictability of user behavior, since these contracts are sold months ahead of time, when only a forecast of user visits is available and (3) the minute amount of resources available online, as an ad server must respond with a matching contract in a fraction of a second. We present a solution to the guaranteed delivery ad serving problem using {\\em compact allocation plans}. These plans, computed offl...
Yeom, Bongjun; Char, Kookheon
2016-06-01
Laminated nanostructures in nacre have been adopted as models in the fabrication of strong, tough synthetic nanocomposites. However, the utilization of CaCO3 biominerals in these composites is limited by the complexity of the synthesis method for nanosized biominerals. In this study, we use the enzymatic reaction of urease to generate a nanoscale CaCO3 thin film to prepare CaCO3/polymer hybrid nanolaminates. Additional layers of CaCO3 thin film are consecutively grown over the base CaCO3 layer with the intercalation of organic layers. The morphology and crystallinity of the added CaCO3 layers depend strongly on the thickness of the organic layer coated on the underlying CaCO3 layer. When the organic layer is less than 20 nm thick, the amorphous CaCO3 layer is spontaneously transformed into crystalline calcite layer during the growth process. We also observe crystalline continuity between adjacent CaCO3 layers through interconnecting mineral bridges. The formation of these mineral bridges is crucial to the epitaxial growth of CaCO3 layers, similar to the formation of natural nacre.
Improvement of SO2 removal by the solubility change of Ca(OH)2 in the spray dryer system.
Song, H C; Park, J W
2001-09-01
Experiments were carried out to verify the effect of the solubility change of the Ca(OH)2 sorbent on the removal of SO2 in a lab-scale spray dryer system. First, to identify the solubility effect, HNO3 was added into Ca(OH)2 slurry to increase the solubility of Ca(OH)2 by neutralization. The improvement of SO2 removal by 5-10% occurred under the condition of both 50% relative solubility and constant pH of slurry. But SO2 removal efficiency decreased steeply when the relative solubility approached 100% and the pH of the slurry decreased rapidly. For the practical application of the solubility effect, NH4Cl and NH4OH were selected as additives. Ammonium chloride (NH4Cl) which could improved Ca(OH)2 solubility removed more SO2 by 5-10% than NH4OH which showed no change in solubility. The optimal result was obtained when the slurry was fed at the ratio of 0.25mol NH4Cl/mol Ca(OH)2. The Ca(OH),/NH4Cl sorbent could remove more SO2 and improve Ca(OH)2 utilization than Ca(OH)2 sorbent in the Ca/S stoichiometric range of 1.0-1.4. It was concluded that the increase of sorbent solubility made the improvement in SO2 removal efficiency and Ca(OH)2 utilization. PMID:11816762
Energy Technology Data Exchange (ETDEWEB)
Nami, B. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Shabestari, S.G., E-mail: shabestari@iust.ac.ir [Center of Excellence for Advanced Materials and Processing (CEAMP), School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Razavi, H. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Mirdamadi, Sh. [Center of Excellence for Advanced Materials and Processing (CEAMP), School of Metallurgy and Materials Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Miresmaeili, S.M. [Department of Mechanical Engineering, Shahid Rajaee Teacher Training University (SRTTU), Lavizan, Tehran (Iran, Islamic Republic of)
2011-01-25
Research highlights: {yields} The size of solid globular {alpha}(Mg) particles decreases in semi-solid slurries of AZ91 alloy by adding Ca and RE elements, whereas it has no considerable effect on the shape factor of the solid particles. {yields} Particle growth in semi-solid slurries of AZ91 and AZRC91 alloys takes place by Ostwald ripening mechanism. {yields} The coarsening rate of solid particles in semi-solid slurries of AZRC91 alloy is lower than that of AZ91 alloy. {yields} Creep properties of AZ91 alloy was improved by adding Ca and RE elements. The thixoformed specimens exhibit the better creep resistance than the as-cast specimens. - Abstract: The effects of calcium and rare earth elements (RE) on the microstructure and creep properties of as-cast and thixoformed AZ91 magnesium alloy have been investigated. It has been shown that the amount of {beta}(Mg{sub 17}Al{sub 12}) intermetallic compound decreases by adding Ca and RE elements into AZ91 alloy and new Al{sub 11}RE{sub 3} and Al{sub 2}Ca intermetallic compounds form in the microstructure. The coarsening of primary {alpha}(Mg) particles in AZ91 alloy and in the Ca and RE containing (AZRC91) alloy takes place by Ostwald ripening mechanism. Adding Ca and RE elements into AZ91 alloy results in a decrease in the coarsening rate of solid particles in semi-solid slurry, whereas it has no visible effect on the shape factor of the solid-particles. The creep properties of AZ91 alloy are improved by adding Ca and RE elements particularly, in the thixoformed condition.
Influence of CaNa2 EDTA on topical 5-aminolaevulinic acid photodynamic therapy
Institute of Scientific and Technical Information of China (English)
刘辉峰; 徐世正; 张春荣
2004-01-01
Background We asssessed whether the CaNa2 EDTA could improve the accumulation of protoporphyrin Ⅸ (PpⅨ) and photosensitisation in HEp-2 cells as well as the depth of treatment of skin cancers on the topical 5-Aminolaevulinic acid (5-ALA) PDT.Methods HEp-2 cells were incubated with 5-ALA (0-1mmol/L) and CaNa2EDTA (0-1mmol/L) for 4 hours, intracellular protoporphyrin Ⅸ content was quantified by extraction, and cell viability was assessed by use of the methyl-tetrazolium (MTT) assay four hours after exposure to light. In comparison with the pictures before and after treatment, depth of treatment could be determined using a Acuson Sequioa 512 phase-array system in paired experiments.Results PpⅨ accumulation increased with increasing extracellular concentrations of ALA (0-1mmol/L). Adding 1mmol/L of CaNa2EDTA increased 30% PpⅨ accumulation over the same period of incubation in the concentration of 1mmol/L ALA. Significant difference was observed between the 5-ALA alone group and 5-ALA combined CaNa2 EDTA group in the PpⅨ accumulation (P<0.01). Cell viability after exposure to light decreased with adding CaNa2 EDTA, a statistical difference in a same fluence above 1.2 J/cm2 between two groups was demonstrated (P<0.05, P<0.01 respectively). Depth of treatment of skin cancers were increased in CaNa2 EDTA-treated group.conclusion CaNa2 EDTA could improve the PpⅨ accumulation and photosensitisation in HEp-2 cells. Clinically, CaNa2 EDTA could increase the depth of treatment in the cutaneous cancers.
Seismic and sedimentological evidence of the 518 AD earthquake at Lake Ohrid (Macedonia/Albania)
Wagner, B.; Francke, A.; Sulpizio, R.; Zanchetta, G.; Lindhorst, K.; Krastel, S.; Vogel, H.
2012-12-01
Lake Ohrid shared by the Republics of Albania and Macedonia is formed by a tectonically active graben within the South Balkan and suggested to be the oldest lake in Europe. Several studies have shown that the lake provides a valuable record of climatic and environmental changes and a distal tephrostratigraphic record of volcanic eruptions from Italy. Fault structures identified in seismic data demonstrate that sediments have also the potential to record tectonic activity in the region. Here, we provide an example of linking tephrostratigraphic information and environmental changes with tectonic activity and anthropogenic impact. Historical documents indicate that a major earthquake destroyed the city of Ohrid at 518 AD. This earthquake is documented in multichannel seismic profiles, in parametric sediment echosounder profiles, and in a ca. 10 m long sediment record from the western part of the lake. The sediment record exhibits a ca. 2 m thick mass wasting event, which is chronologically well constrained by the underlying AD 472 / AD 512 tephra and cross correlation with other sediment sequences with similar geochemical characteristics of the Holocene.
Institute of Scientific and Technical Information of China (English)
Wangxiong Zhao; Qingli Qiao; Dan Wang
2010-01-01
Associative memory, one of the major cognitive functions in the hippocampal CA3 region, includes auto-associative memory and hetero-associative memory. Many previous studies have shown that Alzheimer's disease (AD) can lead to loss of functional synapses in the central nervous system, and associative memory functions in patients with AD are often impaired, but few studies have addressed the effect of AD on hetero-associative memory in the hippocampal CA3 region. In this study, based on a simplified anatomical structure and synaptic connections in the hippocampal CA3 region, a three-layered Hopfield-like neural network model of hippocampal CA3 was proposed and then used to simulate associative memory functions in three circumstances: normal, synaptic deletion and synaptic compensation, according to Ruppin's synaptic deletion and compensation theory. The influences of AD on hetero-associative memory were further analyzed. The simulated results showed that the established three-layered Hopfield-like neural network model of hippocampal CA3 has both auto-associative and hetero-associative memory functions. With increasing synaptic deletion level, both associative memory functions were gradually impaired and the mean firing rates of the neurons within the network model were decreased. With gradual increasing synaptic compensation, the associative memory functions of the network were improved and the mean firing rates were increased. The simulated results suggest that the Hopfield-like neural network model can effectively simulate both associative memory functions of the hippocampal CA3 region. Synaptic deletion affects both auto-associative and hetero-associative memory functions in the hippocampal CA3 region, and can also result in memory dysfunction. To some extent, synaptic compensation measures can offset two kinds of associative memory dysfunction caused by synaptic deletion in the hippocampal CA3 area.
Comparative study of CA242 and CA19-9 for the diagnosis of pancreatic cancer.
Kawa, S; Tokoo, M.; Hasebe, O.; Hayashi, K.; Imai, H; Oguchi, H.; Kiyosawa, K; Furuta, S; Homma, T
1994-01-01
A comparative study of a new tumour marker, CA242, and CA19-9 was conducted with special reference to their diagnostic usefulness in pancreatic cancer. CA242 showed sensitivity similar to that of CA19-9 for overall cases and early cases (stage I tumour) of pancreatic cancer. For other malignancies, the positive rates of CA242 were lower than those of CA19-9 except for colorectal cancer. An important characteristics of CA242 was that it was only slightly and infrequently elevated in the sera o...
Institute of Scientific and Technical Information of China (English)
CHEN Tianran; YU Kefu; ZHAO Jianxin; YAN Hongqiang; SONG Yinxian; FENG Yuexing; CHEN Tegu
2015-01-01
Sea surface temperature (SST) proxies including B/Ca, Mg/Ca, Sr/Ca, U/Ca andδ18O were analyzed in the skeleton of aPorites coral collected from the Zhujiang River (Pearl River) Estuary (ZRE). These geochemical proxies are influenced by river runoff and this area of the northern South China Sea is strongly affected by seasonal freshwater floods. We assessed the robustness of each SST proxy through comparison with the local instrumental SST. Coral Sr/Ca shows the highest correlation with SST variations (r2=0.59), suggesting Sr/Ca is the most robust SST proxy. In contrast, coralδ18O (r2=0.46), B/Ca (r2=0.43) and U/Ca (r2=0.41) ratios were only moderately correlated with SST variations, suggesting that they are disturbed by some other factors in addition to SST. The poor correlation (r2=0.27) between SST and Mg/Ca indicates that Mg/Ca in coral skeletons is not a simple function of SST variations. This may ultimately limit the use of Mg/Ca as a coral paleothermometer.
Thermal AdS(3), BTZ and competing winding modes condensation
Berkooz, Micha; Reichmann, Dori
2007-01-01
We study the thermal physics of AdS(3) and the BTZ black hole when embedded in String theory. The exact calculation of the Hagedorn temperature in TAdS(3) is reinterpreted as the appearance of a winding tachyon. We construct a dual framework for analyzing the phases of the system. In this dual framework, tachyon condensation and geometric capping appear on the same footing, bridging the usual gap of connecting tachyon condensation to modifications of geometry. This allows us to construct in a natural way a candidate for the unstable phase, analogous to a small black hole in higher dimensions. Additional peculiar effects associated with the Hagedorn temperature and the Hawking-Page transition, some to do with the asymptotic structure of AdS(3) and some with strong curvature effects, are analyzed and explained.
Tachyon inflation in an AdS braneworld with back-reaction
Bilic, Neven; Djordjevic, Goran; Milosevic, Milan
2016-01-01
We analyze the inflationary scenario based on the tachyon field coupled with the radion of the second Randall-Sundrum model (RSII). The tachyon Lagrangian is derived from the dynamics of a 3-brane moving in the five dimensional bulk. The AdS$_5$ geometry of the bulk is extended to include the radion. Using the Hamiltonian formalism we find four nonlinear field equations supplemented by the modified Friedmann equations of the RSII braneworld cosmology. After a suitable rescaling we reduce the parameters of our model to only one free parameter related to the brane tension and the AdS$_5$ curvature. We solve the equations numerically assuming a reasonably wide range of initial conditions determined by physical considerations. Varying the free parameter and initial conditions we confront our results with the Planck 2015 data.
Massive quiver matrix models for massive charged particles in AdS
Asplund, Curtis T; Dzienkowski, Eric
2016-01-01
We present a new class of ${\\cal N}=4$ supersymmetric quiver matrix models and argue that it describes the stringy low-energy dynamics of internally wrapped D-branes in four-dimensional anti-de Sitter (AdS) flux compactifications. The Lagrangians of these models differ from previously studied quiver matrix models by the presence of mass terms, associated with the AdS gravitational potential, as well as additional terms dictated by supersymmetry. These give rise to dynamical phenomena typically associated with the presence of fluxes, such as fuzzy membranes, internal cyclotron motion and the appearance of confining strings. We also show how these models can be obtained by dimensional reduction of four-dimensional supersymmetric quiver gauge theories on a three-sphere.
Weak Field Collapse in AdS: Introducing a Charge Density
Caceres, Elena; Pedraza, Juan F; Yang, Di-Lun
2014-01-01
We study the effect of a non-vanishing chemical potential on the thermalization time of a strongly coupled large Nc gauge theory in (2+1)-dimensions, using a specific bottom-up gravity model in asymptotically AdS space. We first construct a perturbative solution to the gravity-equations, which dynamically interpolates between two AdS black hole backgrounds with different temperatures and chemical potentials, in a perturbative expansion of a bulk neutral scalar field. In the dual field theory, this corresponds to a quench dynamics by a marginal operator, where the corresponding coupling serves as the small parameter in which the perturbation is carried out. The evolution of non-local observables, such as the entanglement entropy, suggests that thermalization time decreases with increasing chemical potential. We also comment on the validity of our perturbative analysis.
Quantum Strings and the AdS4/CFT3 Interpolating Function
Abbott, Michael C; Bombardelli, Diego
2010-01-01
The existence of a nontrivial interpolating function h({\\lambda}) is one of the novel features of the new AdS4/CFT3 correspondence involving ABJM theory. At strong coupling, most of the investigation of semiclassical effects so far has been for strings in the AdS4 sector. Several cutoff prescriptions have been proposed, leading to different predictions for the constant term in the expansion h({\\lambda})=\\sqrt[2]{({\\lambda}/2)} + c + ... . We calculate quantum corrections to giant magnons, using the algebraic curve, and show by comparing to the dispersion relation that the same prescriptions lead to the same values of c in this CP3 sector. We then turn to finite-J effects, where a comparison with the L\\"uscher F-term correction shows a mismatch for one of the three sum prescriptions.
Supersymmetric AdS$_{5}$ solutions of type IIB supergravity without D3 branes
Couzens, Christopher
2016-01-01
We analyse the most general bosonic supersymmetric solutions of type IIB supergravity whose metrics are warped products of five-dimensional anti-de Sitter space (AdS$_5$) with a five-dimensional Riemannian manifold $M_{5}$, where the five-form flux vanishes, while all remaining fluxes are allowed to be non-vanishing consistent with SO(4,2) symmetry. This completes the program of classifying all supersymmetric solutions of ten and eleven-dimensional supergravity with an AdS$_5$ factor. We investigate the supersymmetry conditions in some special cases, and demonstrate how these are satisfied by a solution originally found in arXiv:1410.2650[hep-th], utilising the method of non-Abelian T-duality.
Coordinate dependence of Chern-Simons theory on noncommutative AdS3
International Nuclear Information System (INIS)
We investigate the coordinate dependence of noncommutative theory by studying the solutions of noncommutative U(1, 1) x U(1, 1) Chern-Simons theory on AdS3 in polar and rectangular coordinates. We assume that only the space coordinates are noncommuting. When the two coordinate systems are equivalent only up to first order in the noncommutativity parameter θ, we investigate the effect of this non-exact equivalence between the two coordinate systems for two cases, a conical solution and a BTZ black hole solution in noncommutative AdS3, by using the Seiberg-Witten map. In each case, the noncommutative solutions in the two coordinate systems obtained from the same corresponding commutative solution turn out to be different even to the first order in θ.
The Sound of Strongly Coupled Field Theories: Quasinormal Modes In AdS
Landsteiner, Karl
2012-01-01
The AdS/CFT correspondence has developed over the last years into a very useful and powerful tool for studying strongly coupled field theories at finite temperature and density. Of particular interest is the regime of near equilibrium real time evolution that can be captured via linear response theory. The AdS/CFT correspondence allows the calculation of retarded two point functions of gauge invariant operators by studying fluctuations around asymptotically AdS black holes. A major role is played by the poles of these holographic response functions: the quasinormal frequencies. I will review the applications of these ideas to the hydrodynamics of the strongly coupled quark gluon plasma and the holographic realization of strongly coupled superfluids.
Unparticles as the Holographic Dual of Gapped AdS Gravity
Domokos, Sophia K
2015-01-01
Naively applying holographic duality to gapped gravity on Anti de Sitter (AdS) space seems to suggest that the stress tensor of the field theory dual cannot be conserved. On the other hand, by symmetry arguments, it seems that the dual should not violate Poincare symmetry. To clarify this apparent contradiction, we study a holographic dual of massive gravity where both the physical background metric and the fiducial metric are AdS. Using the anomalous scaling of the energy momentum tensor as our guide, we conclude that the dual theory is nonlocal. We find that the dual is similar to conformal invariant "unparticle" theories. We show that such theories can be viewed as dimensional reductions of flat-space field theories with inhomogeneous scaling properties.
Renormalization, averaging, conservation laws and AdS (in)stability
Craps, Ben; Evnin, Oleg; Vanhoof, Joris
2015-01-01
We continue our analytic investigations of non-linear spherically symmetric perturbations around the anti-de Sitter background in gravity-scalar field systems, and focus on conservation laws restricting the (perturbatively) slow drift of energy between the different normal modes due to non-linearities. We discover two conservation laws in addition to the energy conservation previously discussed in relation to AdS instability. A similar set of three conservation laws was previously noted for a self-interacting scalar field in a non-dynamical AdS background, and we highlight the similarities of this system to the fully dynamical case of gravitational instability. The nature of these conservation laws is best understood through an appeal to averaging methods which allow one to derive an effective Lagrangian or Hamiltonian description of the slow energy transfer between the normal modes. The conservation laws in question then follow from explicit symmetries of this averaged effective theory.
D-instanton in AdS sub 5 and instanton in SYM sub 4
Chu, C S; Wu, Y Y
1999-01-01
Following the observation of Banks and Green that the D-instantons in AdS sub 5 correspond to the instantons in four-dimensional supersymmetric Yang-Mills theory, we study in more detail this correspondence for individual instantons. The supergravity solution for a D-instanton in AdS sub 5 is found using the ansatz used previously for D-instantons in flat space. We check that the actions and supersymmetries match between the D-instanton solution and the Yang-Mills instanton. Generalizing this result, we propose that any supergravity solution satisfying the ansatz corresponds to a (anti-) self-dual Yang-Mills configuration. Using this ansatz a family of identities for correlation functions in the supersymmetric Yang-Mills theory are derived.
P-V criticality of AdS black holes in a general framework
Majhi, Bibhas Ranjan
2016-01-01
Interpreting the cosmological constant as pressure, it has been observed that AdS black holes behave as van der Waals system. The critical exponents for the phase transition for all AdS black holes are exactly same as those for the van der Waals system. Till now this has been observed case by case. Here, without using any specific form of the black hole metric, we present a general framework based on just two universal inputs. These are the general forms of the Smarr formula and the first law of thermodynamics. We find that the same values of the critical exponents can be obtained by this general analysis. Therefore there is no need to investigate for a particular metric. The importance of our analysis is that it highlights the observed universality, as well as revels the reason for such universality.
Non-Supersymmetric CS-Matter Theories with Known AdS Duals
Directory of Open Access Journals (Sweden)
Davide Forcella
2011-01-01
Full Text Available We consider three-dimensional conformal field theories living on a stack of N anti-M2 branes at the tip of eight-dimensional supersymmetric cones. The corresponding supergravity solution is obtained by changing sign to the four-form in the Freund-Rubin solution representing M2 branes (“skew-whiffing” transformation and it is known to be stable. The existence of these non-supersymmetric, stable field theories, at least in the large N limit, is a peculiarity of the AdS 4 / CFT 3 correspondence with respect to the usual AdS 5 / CFT 4 , and it is worthwhile to study it. We analyze in detail the KK spectrum of the skew-whiffed solution associated with S 7 / ℤ k and we speculate on the natural field content for a candidate non-supersymmetric dual field theory.
Non-supersymmetric CS-matter theories with known AdS duals
Forcella, Davide
2011-01-01
We consider three dimensional conformal field theories living on a stack of N anti-M2 branes at the tip of eight-dimensional supersymmetric cones. The corresponding supergravity solution is obtained by changing sign to the four-form in the Freund-Rubin solution representing M2 branes ("skew-whiffing" transformation) and it is known to be stable. The existence of these non supersymmetric, stable field theories, at least in the large N limit, is a peculiarity of the AdS4/CFT3 correspondence with respect to the usual AdS5/CFT4, and it is worthwhile to study it. We analyze in detail the KK spectrum of the skew-whiffed solution associated with S^7/Z_k and we speculate on the natural field content for a candidate non-supersymmetric dual field theory.
CFT dual of charged AdS black hole in the large dimension limit
Guo, Er-Dong; Sun, Jia-Rui
2015-01-01
We study the dual CFT description of the $d+1$-dimensional Reissner-Nordstr\\"om-Anti de Sitter (RN-AdS$_{d+1}$) black hole in the large dimension (large $d$) limit, both for the extremal and nonextremal cases. The central charge of the dual CFT$_2$ (or chiral CFT$_1$) is calculated for the near horizon near extremal geometry which possess an AdS$_2$ structure. Besides, the $Q$-picture hidden conformal symmetry in the nonextremal background can be naturally obtained by a probe charged scalar field in the large $d$ limit, without the need to input the usual limits to probe the hidden conformal symmetry. Furthermore, an new dual CFT description of the nonextremal RN-AdS$_{d+1}$ black hole is found in the large $d$ limit and the duality is analyzed by comparing the entropies, the absorption cross sections and the retarded Green's functions obtained both from the gravity and the dual CFT sides.
Witten diagrams revisited: the AdS geometry of conformal blocks
Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River
2016-01-01
We develop a new method for decomposing Witten diagrams into conformal blocks. The steps involved are elementary, requiring no explicit integration, and operate directly in position space. Central to this construction is an appealingly simple answer to the question: what object in AdS computes a conformal block? The answer is a "geodesic Witten diagram", which is essentially an ordinary exchange Witten diagram, except that the cubic vertices are not integrated over all of AdS, but only over bulk geodesics connecting the boundary operators. In particular, we consider the case of four-point functions of scalar operators, and show how to easily reproduce existing results for the relevant conformal blocks in arbitrary dimension.
Witten Diagrams Revisited: The AdS Geometry of Conformal Blocks
Hijano, Eliot; Perlmutter, Eric; Snively, River
2015-01-01
We develop a new method for decomposing Witten diagrams into conformal blocks. The steps involved are elementary, requiring no explicit integration, and operate directly in position space. Central to this construction is an appealingly simple answer to the question: what object in AdS computes a conformal block? The answer is a "geodesic Witten diagram," which is essentially an ordinary exchange Witten diagram, except that the cubic vertices are not integrated over all of AdS, but only over bulk geodesics connecting the boundary operators. In particular, we consider the case of four-point functions of scalar operators, and show how to easily reproduce existing results for the relevant conformal blocks in arbitrary dimension.
The complete AdS_3 x S^3 x T^4 worldsheet S-matrix
Borsato, Riccardo; Sfondrini, Alessandro; Stefanski, Bogdan
2014-01-01
We derive the non-perturbative worldsheet S matrix for fundamental excitations of Type IIB superstring theory on AdS_3 x S^3 x T^4 with Ramond-Ramond flux. To this end, we study the off-shell symmetry algebra of the theory and its representations. We use these to determine the S matrix up to scalar factors and we derive the crossing equations that these scalar factors satisfy. Our treatment automatically includes fundamental massless excitations, removing a long-standing obstacle in using integrability to study the AdS_3/CFT_2 correspondence. The present paper contains a detailed derivation of results first announced in arXiv:1403.4543.
Multiple Ca2+ sensors in secretion
DEFF Research Database (Denmark)
Walter, Alexander M; Groffen, Alexander J; Sørensen, Jakob Balslev;
2011-01-01
Regulated neurotransmitter secretion depends on Ca(2+) sensors, C2 domain proteins that associate with phospholipids and soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE) complexes to trigger release upon Ca(2+) binding. Ca(2+) sensors are thought to prevent spontaneous...... fusion at rest (clamping) and to promote fusion upon Ca(2+) activation. At least eight, often coexpressed, Ca(2+) sensors have been identified in mammals. Accumulating evidence suggests that multiple Ca(2+) sensors interact, rather than work autonomously, to produce the complex secretory response...... observed in neurons and secretory cells. In this review, we present several working models to describe how different sensors might be arranged to mediate synchronous, asynchronous and spontaneous neurotransmitter release. We discuss the scenario that different Ca(2+) sensors typically act on one shared...
STATISTICAL ENTROPIES OF THE TAUB-NUT/BOLT AdS SPACES FROM THE HORIZON CONFORMAL FIELD THEORY
Institute of Scientific and Technical Information of China (English)
JING JI-LIANG; ZHOU SAN-QING; HUANG YI-BIN
2001-01-01
The covariant phase technique is used to compute the constraint algebra of the four-dimensional space-times which are asymptotic to anti-de Sitter (AdS), such as the planar Taub-NUT AdS and Taub-bolt AdS spaces, and the hyperbolic Taub-bolt AdS space. The standard Virasoro subalgebrae with corresponding central charges for these objects are constructed and the resulting densities of states yield the expected Bekenstein-Hawking entropies.
Quarter-BPS Black Holes in AdS$_4$-NUT from $N=2$ Gauged Supergravity
Erbin, Harold
2015-01-01
We study $N=2$ gauged supergravity with $U(1)$ gauge group coupled to $n_v$ vector multiplets and find quite general analytic solutions for quarter-BPS black holes with mass, NUT and dyonic Maxwell charges. The solutions we find have running scalar fields and flow in the IR region to a horizon geometry of the form AdS$_2\\times \\Sigma_g$.
AdS2xS2 as an exact heterotic string background
Orlando, Domenico
2005-01-01
An exact heterotic string theory on an AdS2xS2 background supported by an electromagnetic flux is found as a marginal deformation of an SL(2,R)xSU(2) WZW model. Based on a talk given at NATO Advanced Study Institute and EC Summer School on String Theory: from Gauge Interactions to Cosmology, Cargese, Corsica, France, 7 Jun - 19 Jun 2004.
P-V criticality of charged AdS black holes
Kubiznak, David; Robert B. Mann
2012-01-01
Treating the cosmological constant as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume, we reconsider the critical behaviour of charged AdS black holes. We complete the analogy of this system with the liquid-gas system and study its critical point, which occurs at the point of divergence of specific heat at constant pressure. We calculate the critical exponents and show that they coincide with those of the Van der Waals system.
Generalised Structures for $\\mathcal{N}=1$ AdS Backgrounds
Coimbra, André
2015-01-01
We expand upon a claim made in a recent paper [arXiv:1411.5721] that generic minimally supersymmetric AdS backgrounds of warped flux compactifications of Type II and M theory can be understood as satisfying a straightforward weak integrability condition in the language of $E_{d(d)}\\times\\mathbb{R}^+$ generalised geometry. Namely, they are spaces admitting a generalised $G$-structure set by the Killing spinor and with constant singlet generalised intrinsic torsion.
Pre-potential in the $AdS_{5}\\,\\times\\,S^{5}$ Type IIB superspace
Poláček, Martin
2016-01-01
We found the pre-potential in the superspace with $AdS_{5}\\,\\times\\,S^{5}$ background. The pre-potential appears as part of the vielbeins, without derivatives. The space-cone gauge destroys the bulk Lorentz covariance, but still preserves boundary Lorentz covariance (projective superspace) $SO\\,(\\,3,\\,1\\,)\\,\\otimes\\,SO\\,(\\,4\\,)$, i.e. symmetries of boundary CFT are manifest.
$\\mathcal{N}=1$ AdS$_4$ sourceless vacua in type IIB
Solard, Gautier
2016-01-01
In this paper, we are looking for $\\mathcal{N}=1$, AdS$_4$ sourceless vacua in type IIB. While several examples exist in type IIA , there exists only one example of such vacua in type IIB . Thanks to the framework of generalized geometry we were able to devise a semi-algorithmical method to look for sourceless vacua. We present this method, which can easily be generalized to more complex cases, and give two new sourceless vacua in type IIB.
Global properties of causal wedges in asymptotically AdS spacetimes
Hubeny, Veronika E; Tonni, Erik
2013-01-01
We examine general features of causal wedges in asymptotically AdS spacetimes and show that in a wide variety of cases they have non-trivial topology. We also prove some general results regarding minimal area surfaces on the causal wedge boundary and thereby derive constraints on the causal holographic information. We go on to demonstrate that certain properties of the causal wedge impact significantly on features of extremal surfaces which are relevant for computation of holographic entanglement entropy.
Time-Dependent AdS Backgrounds from S-Branes
Deger, Nihat Sadik
2016-01-01
We construct time and radial dependent solutions that describe p-branes in chargeless S-brane backgrounds. In particular, there are some new M5- and D3-branes among our solutions which have AdS limits and contain a cosmological singularity as well. We also find a time-dependent version of the dyonic membrane configuration in 11-dimensions by applying a Lunin-Maldacena deformation to our new M5-brane solution.
Testing quantum gravity effects through Dyonic charged AdS black hole
Sadeghi, J.; Pourhassan, B.; Rostami, M.
2016-01-01
In this paper, we consider dyonic charged AdS black hole which is holographic dual of a van der Waals fluid. We use logarithmic corrected entropy and study thermodynamics of the black hole and show that holographic picture is still valid. Critical behaviors and stability also discussed. Logarithmic corrections arises due to thermal fluctuations which are important when size of black hole be small. So, thermal fluctuations interpreted as quantum effect. It means that we can see quantum effect ...
Free boundary conditions and the AdS3/CFT2 correspondence
International Nuclear Information System (INIS)
We show that recently proposed free boundary conditions for AdS3 are dual to two-dimensional quantum gravity in certain fixed gauges. In particular, we note that an appropriate identification of the generator of Virasoro transformations leads to a vanishing total central charge in agreement with the theory at the boundary. We argue that this identification is necessary to match the bulk and boundary generators of Virasoro transformations and for consistency with the constraint equations
Graviton and scalar propagations on AdS(4) space in f(R) gravities
Myung, Yun Soo
2010-01-01
We investigate propagations of graviton and additional scalar on four-dimensional anti de Sitter (AdS$_4$) space using $f(R)$ gravity models with external sources. It is shown that there is the van Dam-Veltman-Zakharov (vDVZ) discontinuity in $f(R)$ gravity models because $f(R)$ gravity implies GR with additional scalar. This indicates a difference between general relativity and $f(R)$ gravity clearly.
Renormalization, averaging, conservation laws and AdS (in)stability
Craps, Ben; Evnin, Oleg; Vanhoof, Joris
2015-01-01
We continue our analytic investigations of non-linear spherically symmetric perturbations around the anti-de Sitter background in gravity-scalar field systems, and focus on conservation laws restricting the (perturbatively) slow drift of energy between the different normal modes due to non-linearities. We discover two conservation laws in addition to the energy conservation previously discussed in relation to AdS instability. A similar set of three conservation laws was previously noted for a...
Generalized thermodynamic identity and new Maxwell's law for charged AdS black hole
Zhao, Zixu
2016-01-01
We study the thermodynamic properties of the RN-AdS black hole in full phase space and propose a generalized thermodynamic identity. As an example, we use it to find relations of thermodynamical coefficients between the grand canonical and canonical ensembles. We also show, for the first order phase transition, that the usual Maxwell's equal area law should be extended to a new form for the RN-AdS black hole.
Exact microstate counting for dyonic black holes in AdS4
Benini, Francesco; Zaffaroni, Alberto
2016-01-01
We present a counting of microstates of a class of dyonic BPS black holes in AdS$_4$ which precisely reproduces their Bekenstein-Hawking entropy. The counting is performed in the dual boundary description, that provides a non-perturbative definition of quantum gravity, in terms of a twisted and mass-deformed ABJM theory. We evaluate its twisted index and propose an extremization principle to extract the entropy, which reproduces the attractor mechanism in gauged supergravity.
Effect of Ca and Y additions on oxidation behavior of AZ91 alloy at elevated temperatures
Institute of Scientific and Technical Information of China (English)
CHENG Su-ling; YANG Gen-cang; FAN Jian-feng; LI You-jie; ZHOU Yao-he
2009-01-01
In order to develop the ignition-proof magnesium alloy, the effect of alloying elements, Ca and Y, on the oxidation behavior of AZ91 magnesium alloy at elevated temperatures was investigated. The ignition-proof performance, oxide products and oxidation kinetics of Ca- and Y-containing AZ91 alloys were studied. The results indicate that the proper addition of Ca can increase the ignition point of AZ91 alloy greatly. However, the oxide film of Ca-bearing AZ91 alloy formed at elevated temperature is thick and brittle, which is prone to crack in melting and cooling process. In addition, the oxide film of AZ91-xCa alloy is incompact and cannot inhibit the diffusion of reaction particles. The oxide film of AZ91-xCa alloy turns to thin and plastic one after Y is added, and the density of the oxide film increases greatly due to the formation of composite oxide film composed of MgO, CaO and Y2O3.
In situ biosynthesis of bacterial nanocellulose-CaCO3 hybrid bionanocomposite: One-step process.
Mohammadkazemi, Faranak; Faria, Marisa; Cordeiro, Nereida
2016-08-01
In this work, a simple and green route to the synthesis of the bacterial nanocellulose-calcium carbonate (BNC/CaCO3) hybrid bionanocomposites using one-step in situ biosynthesis was studied. The CaCO3 was incorporated in the bacterial nanocellulose structure during the cellulose biosynthesis by Gluconacetobacter xylinus PTCC 1734 bacteria. Hestrin-Schramm (HS) and Zhou (Z) culture media were used to the hybrid bionanocomposites production and the effect of ethanol addition was investigated. Attenuated total reflection Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, inverse gas chromatography and thermogravimetric analysis were used to characterize the samples. The experimental results demonstrated that the ethanol and culture medium play an important role in the BNC/CaCO3 hybrid bionanocomposites production, structure and properties. The BNC/CaCO3 biosynthesized in Z culture medium revealed higher O/C ratio and amphoteric surface character, which justify the highest CaCO3 content incorporation. The CaCO3 was incorporated into the cellulosic matrix decreasing the bacterial nanocellulose crystallinity. This work reveals the high potential of in situ biosynthesis of BNC/CaCO3 hybrid bionanocomposites and opens a new way to the high value-added applications of bacterial nanocellulose. PMID:27157766
Institute of Scientific and Technical Information of China (English)
杨文修; 王津; 李俊英; 余奕; 许文胜
2001-01-01
利用Fluo－3荧光探针检测细胞内自由Ca2＋浓度([Ca2＋]i),研究了大黄素升高豚鼠结肠带细胞[Ca2＋]i的量—效关系和动态变化特征,及GDP和胞外Ca2＋浓度对其的影响。较低浓度大黄素随药物浓度增加使[Ca2＋]i显著升高，更高浓度大黄素有超最大抑制效应。GDP对大黄素升高细胞[Ca2＋]i的抑制作用随其浓度增加而增强。GDP和胞外Ca2＋浓度影响大黄素诱发的[Ca2＋]i动态变化的结果表明：GDP使[Ca2＋]i峰消失，胞外无Ca2＋导致[Ca2＋]i随时间显著下降，大黄素升高[Ca2＋]i作用趋向消失。%Intracellular free Ca2+concentration ([Ca2+]i) was detected usingFluo-3 fluorescence probe.Relationship between emodin concentration and intracellular [Ca2+]i as well as kinetics of [Ca2+]i in guinea pig taenia coli cells were studied.In the range of lower emodin concentration,[Ca2+]i rose remarkably with increasing of drug concentration.Supermaximal stimulation of emodin inhibited rising of [Ca2+]i.Inhibition of GDP on rising of [Ca2+]i enhanced with increasing of GDP concentration.Effects of GDP and extracellular Ca2+-free on rising kinetics of emodin evoked [Ca2+]i were studied.Peak of [Ca2+]i disappeared by adding GDP.When extracellular Ca2+-free,[Ca2+]i decreased remarkably with prolonging of time,rising of emodin evoked [Ca2+]i tended to disappear.These results suggest that emodin could evoke Ca2+release from intracellular Ca2+pool by activating receptor coupled G protein and promote extracellular Ca2+influx by depolarizing cell membrane potential.
Exact black hole formation in asymptotically (AdS and flat spacetimes
Directory of Open Access Journals (Sweden)
Xuefeng Zhang
2014-09-01
Full Text Available We consider four-dimensional Einstein gravity minimally coupled to a dilaton scalar field with a supergravity-inspired scalar potential. We obtain an exact time-dependent spherically symmetric solution describing gravitational collapse to a static scalar-hairy black hole. The solution can be asymptotically AdS, flat or dS depending on the value of the cosmological constant parameter Λ in the potential. As the advanced time u increases, the metric approaches the static limit in an exponential fashion, i.e., e−u/u0 with u0∼1/(α4M01/3, where M0 is the mass of the final black hole and α is the second parameter in the potential. Similarly to the Vaidya solution, at u=0, the spacetime can be matched to an (AdS or flat vacuum except that at the origin a naked singularity may occur. Moreover, a limiting case of our solution with α=0 gives rise to an (AdS generalization of the Roberts solution. Our results provide a new model for investigating formation of real life black holes with Λ≥0. For Λ<0, it can be instead used to study non-equilibrium thermalization of certain strongly-coupled field theory.
On elliptic string solutions in AdS3 and dS3
Bakas, Ioannis; Pastras, Georgios
2016-07-01
Classical string actions in AdS3 and dS3 can be connected to the sinh-Gordon and cosh-Gordon equations through Pohlmeyer reduction. We show that the problem of constructing a classical string solution with a given static or translationally invariant Pohlmeyer counterpart is equivalent to solving four pairs of effective Schrödinger problems. Each pair consists of a flat potential and an n = 1 Lamé potential whose eigenvalues are connected, and, additionally, the four solutions satisfy a set of constraints. An approach for solving this system is developed by employing an interesting connection between the specific class of classical string solutions and the band structure of the Lamé potential. This method is used for the construction of several families of classical string solutions, one of which turns out to be the spiky strings in AdS3. New solutions include circular rotating strings in AdS3 with singular time evolution of their radius and angular velocity as well as classical string solutions in dS3.
On Elliptic String Solutions in AdS$_3$ and dS$_3$
Bakas, Ioannis
2016-01-01
Classical String actions in AdS$_3$ and dS$_3$ can be connected to the sinh-Gordon and cosh-Gordon equations through Pohlmeyer reduction. We show that the problem of constructing a classical string solution with a given static or translationally invariant Pohlmeyer counterpart is equivalent to solving four pairs of effective Schr\\"{o}dinger problems. Each pair consists of a flat potential and an $n = 1$ Lam\\'e potential whose eigenvalues are connected, and, additionally, the four solutions satisfy a set of constraints. An approach for solving this system is developed by employing an interesting connection between the specific class of classical string solutions and the band structure of the Lam\\'e potential. This method is used for the construction of several families of classical string solutions, one of which turns out to be the spiky strings in AdS$_3$. New solutions include circular rotating strings in AdS$_3$ with singular time evolution of their radius and angular velocity as well as classical string so...
浅析Ad Hoc网络%A Superficial Analysis of Ad Hoc Networks
Institute of Scientific and Technical Information of China (English)
王建宽
2011-01-01
Ad Hoc network is a new-type, multi-hop, self-organizing wireless networks, compensating the limited transmission distance of wireless devices by multi-hop technology. Network nodes can be dynamically , ~eely and frequendy joining or quitting the network, so it can broaden the network coverage, and provide users with various services. This article introduces the concept, characteristics, applications and architecture of Ad Hoc networks, and the key technology that the Ad Hoc network requires.%Ad Hoc网络是一种新型、多跳、自组织的无线网络，借助于多跳转发技术弥补无线设备传输距离的有限性。网络节点能够动态地、随意地、频繁地进入和离开网络，从而拓宽了网络的覆盖范围，为用户提供各种服务。文中介绍了Ad Hoc网络的概念、特点、应用领域和体系结构，并指出了Ad Hoc网络需要的关键技术。
Korean Nova Records in A.D. 1073 and A.D. 1074: R Aquarii
Yang, H J; Cho, S H; Park, C; Yang, Hong-Jin; Park, Myeong-Gu; Cho, Se-Hyung; Park, Changbom
2005-01-01
R Aqr is known to be a symbiotic binary system with an associated extended emission nebula, possibly produced by a historic outburst. To find the associated historic records, we searched for and compiled all 'Guest Star' and 'Peculiar Star' records in three Korean 'official' history books that cover almost two thousand years, Samguksagi, Goryeosa, Joseonwangjosillok. In addition to the record of A.D. 1073, previously noted by Li (1985), we have found in Goryeosa another candidate record of A.D. 1074, which has the same positional description as that of A.D. 1073 with an additional brightness description. We examined various aspects of the two records and conclude that they both are likely to be the records of outburst of R Aqr. This means that there were two successive outbursts in A.D. 1073 and in A.D. 1074, separated by approximately one year. Based on these records, we estimate the distance to R Aqr to be 273 pc if the expansion of the nebula has been at a constant rate. The brightness record of A.D. 1074 ...
Superradiance and instability of small rotating charged AdS black holes in all dimensions
Energy Technology Data Exchange (ETDEWEB)
Aliev, Alikram N. [Yeni Yuezyil University, Faculty of Engineering and Architecture, Istanbul (Turkey)
2016-02-15
Rotating small AdS black holes exhibit the superradiant instability to low-frequency scalar perturbations, which is amenable to a complete analytic description in four dimensions. In this paper, we extend this description to all higher dimensions, focusing on slowly rotating charged AdS black holes with a single angular momentum. We divide the spacetime of these black holes into the near-horizon and far regions and find solutions to the scalar wave equation in each of these regions. Next, we perform the matching of these solutions in the overlap between the regions, by employing the idea that the orbital quantum number l can be thought of as an approximate integer. Thus, we obtain the complete low-frequency solution that allows us to calculate the complex frequency spectrum of quasinormal modes, whose imaginary part is determined by a small damping parameter. Finally, we find a remarkably instructive expression for the damping parameter, which appears to be a complex quantity in general. We show that the real part of the damping parameter can be used to give a universal analytic description of the superradiant instability for slowly rotating charged AdS black holes in all spacetime dimensions. (orig.)
Non-split and split deformations of AdS_5
Hoare, Ben
2016-01-01
The eta-deformation of the AdS_5 x S^5 superstring depends on a non-split r matrix for the superalgebra psu(2,2|4). Much of the investigation into this model has considered one particular choice, however there are a number of inequivalent alternatives. This is also true for the bosonic sector of the theory with su(2,2), the isometry algebra of AdS_5, admitting one split and three non-split r matrices. In this article we explore these r matrices and the corresponding geometries. We investigate their contraction limits, comment on supergravity backgrounds and demonstrate their relation to gauged-WZW deformations. We then extend the three non-split cases to AdS_5 x S^5 and compute four separate bosonic two-particle tree-level S-matrices based on inequivalent BMN-type light-cone gauges. The resulting S-matrices, while different, are related by momentum-dependent one-particle changes of basis.
Nonlinear sigma models with AdS supersymmetry in three dimensions
Butter, Daniel; Tartaglino-Mazzucchelli, Gabriele
2012-01-01
In three-dimensional anti-de Sitter (AdS) space, there exist several realizations of N-extended supersymmetry, which are traditionally labelled by two non-negative integers p>=q such that p+q=N. Different choices of p and q, with N fixed, prove to lead to different restrictions on the target space geometry of supersymmetric nonlinear sigma-models. We classify all possible types of hyperkahler target spaces for the cases N=3 and N=4 by making use of two different realizations for the most general (p,q) supersymmetric sigma-models: (i) off-shell formulations in terms of N=3 and N=4 projective supermultiplets; and (ii) on-shell formulations in terms of covariantly chiral scalar superfields in (2,0) AdS superspace. Depending on the type of N=3,4 AdS supersymmetry, nonlinear sigma-models can support one of the following target space geometries: (i) hyperkahler cones; (ii) non-compact hyperkahler manifolds with a U(1) isometry group which acts non-trivially on the two-sphere of complex structures; (iii) arbitrary h...
First order semiclassical thermal string in the AdS spacetime
Belich, Humberto; da Graça, Edison Luiz; dos Santos, Marco Antonio; Vasile Vancea, Ion
2007-02-01
We formulate the finite temperature theory for the free thermal excitations of the bosonic string in the anti-de Sitter (AdS) spacetime in the Thermo Field Dynamics (TFD) approach. The spacetime metric is treated exactly while the string and the thermal reservoir are semiclassically quantized at the first order perturbation theory with respect to the dimensionless parameter epsilon = α'H-2. In the conformal D = 2+1 black-hole AdS background the quantization is exact. The method can be extended to the arbitrary AdS spacetime only in the first order perturbation. This approximation is taken in the center of mass reference frame and it is justified by the fact that at the first order the string dynamics is determined only by the interaction between the free string oscillation modes and the exact background. The first order thermal string is obtained by thermalization of the T = 0 system carried on by the TFD Bogoliubov operator. We determine the free thermal string states and compute the local entropy and free energy in the center of mass reference frame.