10,091 research outputs found
Potential of a Neutrino Detector in the ANDES Underground Laboratory for Geophysics and Astrophysics of Neutrinos
The construction of the Agua Negra tunnels that will link Argentina and Chile
under the Andes, the world longest mountain range, opens the possibility to
build the first deep underground labo- ratory in the Southern Hemisphere. This
laboratory has the acronym ANDES (Agua Negra Deep Experiment Site) and its
overburden could be as large as \sim 1.7 km of rock, or 4500 mwe, providing an
excellent low background environment to study physics of rare events like the
ones induced by neutrinos and/or dark matter. In this paper we investigate the
physics potential of a few kiloton size liquid scintillator detector, which
could be constructed in the ANDES laboratory as one of its possible scientific
programs. In particular, we evaluate the impact of such a detector for the
studies of geoneutrinos and galactic supernova neutrinos assuming a fiducial
volume of 3 kilotons as a reference size. We emphasize the complementary roles
of such a detector to the ones in the Northern Hemisphere neutrino facilities
through some advantages due to its geographical location.Comment: 20 pages, 16 figures and 9 table
Avaliação da resistência de variedades de mangueira Mangifera indica L., do BAG manga da Embrapa Mandioca e Fruticultura, ao fungo Coletotrichum gloeosporioides, Penz.).
O Brasil está entre os nove principais produtores de manga do mundo, com uma área de 67 mil hectares. Atualmente, a Tommy Atkins é a variedade mais produzida e a que possui a maior participação no volume comercializado no mundo, devido, principalmente, as suas caracterÃsticas fenológicas e organolépticas
The value of cell-free circulating tumour DNA profiling in advanced non-small cell lung cancer (NSCLC) management
Liquid biopsy (LB) has boosted a remarkable change in the management of cancer patients by contributing to tumour genomic profiling. Plasma circulating cell-free tumour DNA (ctDNA) is the most widely searched tumour-related element for clinical application. Specifically, for patients with lung cancer, LB has revealed valuable to detect the diversity of targetable genomic alterations and to detect and monitor the emergence of resistance mechanisms. Furthermore, its non-invasive nature helps to overcome the difficulty in obtaining tissue samples, offering a comprehensive view about tumour diversity. However, the use of the LB to support diagnostic and therapeutic decisions still needs further clarification. In this sense, this review aims to provide a critical view of the clinical importance of plasma ctDNA analysis, the most widely applied LB, and its limitations while anticipating concepts that will intersect the present and future of LB in non-small cell lung cancer patients
Vector Meson Production in Ultraperipheral Heavy Ion Collisions
The ultraperipheral heavy ion collisions (UPC's) are an important alternative
to study the QCD dynamics until the next generation of
colliders become reality. Due to the coherent action of all the protons in the
nucleus, the electromagnetic field is very strong and the resulting flux of
equivalent photons is large, which allows to study two-photon as well as
photonuclear interactions at high energies. In this paper we present a brief
review of the vector meson production in UPC's at high energies using the QCD
color dipole approach to describe their photonuclear production and the
perturbative QCD Pomeron (BFKL dynamics) to describe the double meson
production in photon-photon process. Predictions for rates and integrated cross
sections are presented for energies of RHIC and LHC.Comment: 16 pages, 1 figure. Version to be published in Journal of Physics G:
Nuclear and Particle Physic
SOLUTION OF MULTIPHASE HEAT CONDUCTION PROBLEMS VIA THE GENERALIZED INTEGRAL TRANSFORM TECHNIQUE WITH DOMAIN CHARACTERIZATION THROUGH THE INDICATOR FUNCTION
The Generalized Integral Transform Technique (GITT) has appeared in the literature as an alternative to conventional discrete numerical methods for partial differential equations in heat transfer and fluid flow. This method permits the automatic control of the error and is easy to program, since there is no need for a discretization. The method has being constantly improved, but there still a vast number of practical problems that has not being solved satisfactory. In several brands of engineering, the transport equations have to be solved for a combination of different phases or materials or inside irregular domains. In this case, the mathematical resource of the Indicator Function can be employed. This function is a representation of the phases or parts of the domain with the numbers 0 and 1 for each phase. According to the method, the Indicator Function is defined by Poisson’s equation, which is added to the system of the transport equations. An integral is done along the curve that defines the interface that will generate the source term in Poisson’ equation used to calculate the Indicator Function distribution. The solution of the system of equations is done using the common GITT approach. Then, an analytical expression for each transformed potential of the indicator function and the other variables are available. Once the transformed potentials are known, the Indicator Function can be analytically operated, and the interface can be represented by an analytical continuous function. In this work, the use of the GITT in conjunction with the Indicator Function is proposed. The methodology is described and some previous results are presented. GITT is applied to a two-dimensional heat conduction problem in a multiphase domain with an irregular geometry, inside a square domain. The methodology presented here can be extended to all brands of convection-diffusion problems already solved via GITT
Lagrangian formulation of classical fields within Riemann-Liouville fractional derivatives
The classical fields with fractional derivatives are investigated by using
the fractional Lagrangian formulation.The fractional Euler-Lagrange equations
were obtained and two examples were studied.Comment: 9 page
In situ formation of methyl methacrylate / hydroxyapatite - based polymer composites through a sequential bulk-suspension polymerization.
Probing QCD dynamics in two-photon interactions at high energies
In this paper the two-photon interactions at high energies are investigated
considering different approaches for the QCD dynamics. In particular, we
calculate the total cross section in different theoretical
approches and present a comparison among the predictions of the BFKL dynamics
at leading and next-to-leading order with those from saturation physics. We
analyze the possibility that the future linear colliders could discriminate
between these different approaches.Comment: 14 pages, 2 figures. Version to be published in Journal of Physics G:
Nuclear and Particle Physic
The Seyfert Population in the Local Universe
The magnitude-limited catalog of the Southern Sky Redshift Survey (SSRS2), is
used to characterize the properties of galaxies hosting Active Galactic Nuclei.
Using emission-line ratios, we identify a total of 162 (3%) Seyfert galaxies
out of the parent sample with 5399 galaxies. The sample contains 121 Seyfert 2
galaxies and 41 Seyfert 1. The SSRS2 Seyfert galaxies are predominantly in
spirals of types Sb and earlier, or in galaxies with perturbed appearance as
the result of strong interactions or mergers. Seyfert galaxies in this sample
are twice as common in barred hosts than the non-Seyferts. By assigning
galaxies to groups using a percolation algorithm we find that the Seyfert
galaxies in the SSRS2 are more likely to be found in binary systems, when
compared to galaxies in the SSRS2 parent sample. However, there is no
statistically significant difference between the Seyfert and SSRS2 parent
sample when systems with more than 2 galaxies are considered. The analysis of
the present sample suggests that there is a stronger correlation between the
presence of the AGN phenomenon with internal properties of galaxies
(morphology, presence of bar, luminosity) than with environmental effects
(local galaxy density, group velocity dispersion, nearest neighbor distance).Comment: 35 pages, 13 figures, Accepted to be publised in Astronomical Journa
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