The low-energy limit of AdS(3)/CFT2 and its TBA

We investigate low-energy string excitations in AdS3 × S3 × T4. When the worldsheet is decompactified, the theory has gapless modes whose spectrum at low energies is determined by massless relativistic integrable S matrices of the type introduced by Al. B. Zamolodchikov. The S matrices are non-trivial only for excitations with identical worldsheet chirality, indicating that the low-energy theory is a CFT2. We construct a Thermodynamic Bethe Ansatz (TBA) for these excitations and show how the massless modes’ wrapping effects may be incorporated into the AdS3 spectral problem. Using the TBA and its associated Y-system, we determine the central charge of the low-energy CFT2 to be c = 6 from calculating the vacuum energy for antiperiodic fermions — with the vacuum energy being zero for periodic fermions in agreement with a supersymmetric theory — and find the energies of some excited states

Variable stars in one open cluster within the Kepler/K2-Campaign-5 field: M 67 (NGC 2682)

In this paper we continue the release of high-level data products from the multiyear photometric survey collected at the 67/92 cm Schmidt Telescope in Asiago. The primary goal of the survey is to discover and to characterise variable objects and exoplanetary transits in four fields containing five nearby open clusters spanning a broad range of ages. This second paper releases a photometric catalogue, in five photometric bands, of the Solar-age, Solar-metallicity open cluster M 67 (NGC 2682). Proper motions are derived comparing the positions observed in 2013 at the Asiago's Schmidt Telescope with those extracted from [email protected] MPG/ESO images in 2000. We also analyse the variable sources within M 67. We detected 68 variables, 43 of which are new detection. Variable periods and proper-motion memberships of a large majority of sources in our catalogue are improved with respect to previous releases. The entire catalogue will be available in electronic format. Besides the general interest on an improved catalogue, this work will be particularly useful because of: (1) the imminent release of Kepler/K2 Campaign-5 data of this cluster, for which our catalogue will provide an excellent, high spatial resolution input list, and (2) characterisation of the M 67 stars which are targets of intense HARPS and HARPS-N radial-velocity surveys for planet search.Comment: 8 pages, 6 figures (2 at low resolution), 2 tables. Accepted for publication in MNRAS on October 17, 2015. Electronic materials available at the url http://groups.dfa.unipd.it/ESPG/M67.html , and later on the Journal and at the CD

TASTE IV. Refining ephemeris and orbital parameters for HAT-P-20b and WASP-1b

We present four new light curves of transiting exoplanets WASP-1b and HAT-P-20b, observed within the TASTE (The Asiago Search for Transit timing variations of Exoplanets) project. We re-analyzed light curves from the literature in a homogeneous way, calculating a refined ephemeris and orbital-physical parameters for both objects. WASP-1b does not show any significant Transit Timing Variation signal at the 120 s-level. As for HAT-P-20b, we detected a deviation from our re-estimated linear ephemeris that could be ascribed to the presence of a perturber or, more probably, to a previously unnoticed high level of stellar activity. The rotational period of HAT-P-20 A we obtained from archival data (P_rot ~ 14.5 days), combined with its optical variability and strong emission of CaII H&K lines, is consistent with a young stellar age (< 1 Gyr) and support the hypothesis that stellar activity may be responsible of the measured deviations of the transit times.Comment: 7 pages, 4 figures, 3 tables, accepted to Astronomische Nachrichte

Kepler-539: a young extrasolar system with two giant planets on wide orbits and in gravitational interaction

We confirm the planetary nature of Kepler-539b (aka Kepler object of interest K00372.01), a giant transiting exoplanet orbiting a solar-analogue G2 V star. The mass of Kepler-539b was accurately derived thanks to a series of precise radial velocity measurements obtained with the CAFE spectrograph mounted on the CAHA 2.2m telescope. A simultaneous fit of the radial-velocity data and Kepler photometry revealed that Kepler-539b is a dense Jupiter-like planet with a mass of Mp = 0.97 Mjup and a radius of Rp = 0.747 Rjup, making a complete circular revolution around its parent star in 125.6 days. The semi-major axis of the orbit is roughly 0.5 au, implying that the planet is at roughly 0.45 au from the habitable zone. By analysing the mid-transit times of the 12 transit events of Kepler-539b recorded by the Kepler spacecraft, we found a clear modulated transit time variation (TTV), which is attributable to the presence of a planet c in a wider orbit. The few timings available do not allow us to precisely estimate the properties of Kepler-539c and our analysis suggests that it has a mass between 1.2 and 3.6 Mjup, revolving on a very eccentric orbit (0.4<e<0.6) with a period larger than 1000 days. The high eccentricity of planet c is the probable cause of the TTV modulation of planet b. The analysis of the CAFE spectra revealed a relatively high photospheric lithium content, A(Li)=2.48 dex, which, together with both a gyrochronological and isochronal analysis, suggests that the parent star is relatively young.Comment: 11 pages, 14 figures, accepted for publication in Astronomy & Astrophysic

On the spectrum of AdS₃ × S³× T⁴ strings with Ramond–Ramond flux

We analyze the spectrum of perturbative closed strings on AdS₃ × S³× T⁴ with Ramond–Ramond flux using integrable methods. By solving the crossing equations we determine the massless and mixed-mass dressing factors of the worldsheet S matrix and derive the Bethe equations. Using these, we construct the underlying integrable spin chain and show that it reproduces the reducible spin chain conjectured at weak coupling in Olof Ohlsson S, Bogdan S Jr and Torrielli A 2013 (arXiv:1211.1952). We find that the string-theory massless modes are described by gapless excitations of the spin chain. The resulting degeneracy of vacua matches precisely the protected supergravity spectrum found by de Boer

MONTHLY ISOTOPIC SIGNAL OF THE PRECIPITATED WATER IN THE PROVINCE OF TRENTO: LAGRANGIAN ANALYSIS AND DISCUSSION OF MEASUREMENTS

The present work has been performed in the framework of the research project AQUAPAST. The main focus of AQUAPAST is the reconstruction of past climate changes in the atmospheric circulation and in particular in the water vapour transport mechanism over the Mediterranean area starting from the analysis of the isotopic content of cave speleothemes in the Trentino Province (North-East of Italy). A Lagrangian methodology for the reconstruction and the analysis of the airstreams which govern the transport of water vapour has been applied to recent events. The average monthly isotopic signal of the precipitation water sampled in stations located in key geographic settings in the Province of Trento is used as tracer to infer the origin of the precipitating water and to validate the Lagrangian analysis. A comparison between the isotopic signal of November 2002 and November 2003 is here presented, as most of the yearly precipitation falls in November over the Eastern Alps. Hypotheses are proposed about the meteorological factors (e.g. monthly averaged sea surface temperature, atmospheric circulation, etc.) determining different isotopic signals in the two years

Non-Uniform Planar Slicing for Robot-Based Additive Manufacturing

Planar slicing algorithms with constant layer thickness are widely implemented for geometry processing in Additive Manufacturing (AM). Since the build direction is fixed, a staircase effect is produced, decreasing the final surface finish. Also, support structures are required for overhanging portions. To overcome such limits, AM is combined with manipulators and working tables with multiple degrees of freedom. This is called Robot-Based Additive Manufacturing (RBAM) and it aims to increase the manufacturing flexibility of traditional printers, enabling the deposition of material in multiple directions. In particular, the deposition direction is changed at each layer requiring non-uniform thickness slicing. The total number of layers, as well as the volume of the support structures and the manufacturing time are reduced, while the surface finish and mechanical performance of the final product are increased. This paper presents an algorithm for non-uniform planar slicing developed in Rhinoceros and Grasshopper. It processes the input geometry and uses parameters to capture manufacturing limits. It mostly targets curved geometries to remove the need for support structures, also increasing the part quality

Coquetel biológico (EM) no crescimento de mudas de Ocimum basilicum L.

O estudo objetivou avaliar os efeitos de diferentes dosagens de EM (Microorganismos Eficazes) na germinação, emergência, crescimento e qualidade de mudas de manjericão Ocimum basilicum L. As plantas foram cultivadas em bandejas com capacidade para 576 tubetes, em um viveiro localizado no Assentamento Taquaral, Corumbá, MS. O delineamento utilizado foi inteiramente casualizado com quatro tratamentos e cinco repetições. Os tratamentos consistiram em uma base formada por areia, vermicomposto e terra. Essa base recebeu doses crescentes de EM (que é uma combinação de vários microorganismos benéficos, tanto aeróbicos quanto anaeróbicos, que cumprem diferentes funções), que foram preparadas em solução aquosa misturadas ao substrato na proporção 10 ml (0,1%), 30 ml (0,3%) e 60 ml (0,6%). O tratamento a 0,3% (30 ml) apresentou melhor resultado na emergência e no crescimento do manjericão. The study aimed to evaluate the effects of different concentrations doses of EM (Effective Microorganisms) on growth of basil, Ocimum basilicum L. We grow plants in trays with capacity of 576 tubes, in a greenhouse located in Taquaral, Corumbá, Mato Grosso do Sul State. The experimental design was completely randomized, with four treatments, and five repetitions. The substrate was a combination of sand, humus and soil. The treatments consisted of increasing doses of EM in the substrate, which is a combination of several beneficial microorganisms, both aerobic and anaerobic, fulfilling different functions. We prepared in aqueous solution mixed with substrate in proportions 10 ml (0.1%), 30 ml (0.3%) and 60 ml (0.6%). Treatment of 0.3% showed better results in the emergence and growth of basil.Também em: SEMINÁRIO DE AGROECOLOGIA DE MATO GROSSO DO SUL, 4.; ENCONTRO DE PRODUTORES AGROECOLÓGICOS DE MS, 3., 2012, Glória de Dourados. O saber tradicional e o científico: a interação encurtando caminhos para o desenvolvimento sustentável: anais. Brasília, DF: Embrapa, 2012. 1 CD-ROM. Editado por: Leandro Fávio Carneiro, Milton Parron Padovan

Apoio a processo de transição agroecológica: interação entre o científico e o tradicional.

O presente relato tem por objetivo apresentar as experiências desenvolvidas em uma propriedade no assentamento Tamarineiro II-Sul, no município de Corumbá, MS, apoiada pela Embrapa Pantanal, a unidade produtiva encontra-se em transição agroecológica. As atividades fizeram parte do processo de formação do Curso Superior de Tecnologia em Agroecologia e buscou-se possibilitar aos envolvidos gerar conhecimentos a partir de uma prática interativa com a realidade, problematizando o conhecido e investigando o não conhecido de forma a compreendê-lo auxiliando-os a se tornarem credenciados a ter uma presença substantiva a favor do desenvolvimento local e regional. A experiência proporcionou o contato com um saber que o produtor desenvolve no seu dia-a-dia a partir de experiências concreta, desta forma a atividade nessa unidade produtiva auxiliou a formação dos acadêmicos do Curso Superior de Tecnologia em Agroecologia, onde conciliou o saber teórico com a prática de campo, promovendo um amadurecimento e fortalecendo no processo de formação de sua base profissional.Também em SEMINÁRIO DE AGROECOLOGIA DE MATO GROSSO DO SUL, 4.; ENCONTRO DE PRODUTORES AGROECOLÓGICOS DE MS, 3., 2012, Glória de Dourados. O saber tradicional e o científico: a interação encurtando caminhos para o desenvolvimento sustentável: anais. Brasília, DF: Embrapa, 2012. 1 CD-ROM. Editado por: Leandro Fávio Carneiro, Milton Parron Padovan

Desenvolvimento de estacas de Alfavaca (Ocimum gratissimum L.) em direfentes substratos.

O objetivo deste estudo foi avaliar o efeito de diferentes proporções de areia, terra e composto orgânico no crescimento de raízes e parte aérea de estacas de alfavaca, de modo a identificar o substrato que proporciona as melhores condições de pegamento das estacas e desenvolvimento das mudas.bitstream/CPAP-2010/57271/1/COT75.pd