
Agostini, C. A., Silva, C., & Nasirov, S. (2017). Failure of Energy MegaProjects in Chile: A Critical Review from Sustainability Perspectives. Sustainability, 9(6), 17 pp.
Abstract: A number of successive energy crises over the last decade due to the lack of a balanced investment planning in the energy sector in Chile has led to a strong dependence on external sources and also doubled energy prices in the country, thus posing a significant challenge to the local economy. With the purpose of reaching longterm goals while simultaneously addressing shortterm urgencies, Chile seeks to build a consistent and integrated energy policy in order to attract investment in the sector. Despite an overall attractive investment climate and encouraging market conditions in the country, the energy sector has been adversely affected, in particular, by the communities' opposition to megaprojects based on their expected environmental and social impacts. The study highlights recent experiences of energy generation megaprojects in terms of addressing aspects of sustainability. Based on these experiences, it discusses underdeveloped role of environmental evaluations and the main regulatory challenges ahead, recommending then public policies to effectively address these challenges.



AlvarezMiranda, E., & Pereira, J. (2017). Designing and constructing networks under uncertainty in the construction stage: Definition and exact algorithmic approach. Comput. Oper. Res., 81, 178–191.
Abstract: The present work proposes a novel Network Optimization problem whose core is to combine both network design and network construction scheduling under uncertainty into a single twostage robust optimization model. The firststage decisions correspond to those of a classical network design problem, while the secondstage decisions correspond to those of a network construction scheduling problem (NCS) under uncertainty. The resulting problem, which we will refer to as the TwoStage Robust Network Design and Construction Problem (2SRNDC), aims at providing a modeling framework in which the design decision not only depends on the design costs (e.g., distances) but also on the corresponding construction plan (e.g., time to provide service to costumers). We provide motivations, mixed integer programming formulations, and an exact algorithm for the 2SRNDC. Experimental results on a large set of instances show the effectiveness of the model in providing robust solutions, and the capability of the proposed algorithm to provide good solutions in reasonable running times. (C) 2017 Elsevier Ltd. All rights reserved.



Anabalon, A., Astefanesei, D., & Mann, R. (2017). Holographic equation of state in fluid/gravity duality. Phys. Lett. B, 770, 272–277.
Abstract: We establish a precise relation between mixed boundary conditions for scalar fields in asymptotically anti de Sitter spacetimes and the equation of state of the dual fluid. We provide a detailed derivation of the relation in the case of five bulkdimensions for scalar fields saturating the BreitenlohnerFreedman bound. As a concrete example, we discuss the five dimensional scalartensor theories describing dark energy in four dimensions. (C) 2017 Published by Elsevier B.V.



Aquea, F., Timmermann, T., & HerreraVasquez, A. (2017). Chemical inhibition of the histone acetyltransferase activity in Arabidopsis thaliana. Biochem. Biophys. Res. Commun., 483(1), 664–668.
Abstract: Chemical inhibition of chromatin regulators provides an effective approach to investigate the roles of chromatin modifications in plant and animals. In this work, chemical inhibition of the Arabidopsis histone acetyltransferase activity by gammabutyrolactone (MB3), the inhibitor of the catalytic activity of mammalian GENERAL CONTROL NONREPRESSIBLE 5 (GCN5) is evaluated. Arabidopsis seedlings were germinated in LS medium supplemented with different concentrations of MB3, and inhibition in the root length and yellowed leaves were observed. The yellowed leaves phenotype of the plants grown in 100 μM of MB3 was reverted when plants were additionally treated with 1 μM of TSA, a histone deacetylase inhibitor. Using an immunoblot assay with specific antibodies revealed a reduction of H3K14 acetylation levels at 3 and 24 h posttreatment. At 24 h posttreatment a reduction of H3K9 acetylation levels was observed. Targets of GCN5 related to stress were downregulated at 3 h posttreatment but no change was observed in target genes related to developmental transition. Our results indicate that MB3 is a chemical inhibitor of the histone acetyltransferase in Arabidopsis and suggest that this inhibitor could function in other plants species. (C) 2016 Elsevier Inc. All rights reserved.



ArayaLetelier, G., Antico, F. C., Carrasco, M., Rojas, P., & GarcíaHerrera, C. M. (2017). Effectiveness of new natural fibers on damagemechanical performance of mortar. Constr. Build. Mater., 152, 672–682.
Abstract: Abstract
Addition of fibers to cementbased materials improve tensile and flexural strength, fracture toughness, abrasion resistance, delay cracking, and reduce crack widths. Natural fibers have recently become more popular in the construction materials community. This investigation addresses the characterization of a new animal fiber (pig hair), a massive foodindustry waste worldwide, and its use in mortars. Morphological, physical and mechanical properties of pig hair are determined in order to be used as reinforcement in mortars. A sensitivity analysis on the volumes of fiber in mortars is developed. The results from this investigation showed that reinforced mortars significantly improve impact strength, abrasion resistance, plastic shrinkage cracking, age at cracking, and crack widths as fiber volume increases. Other properties such as compressive and flexural strength, density, porosity and modulus of elasticity of reinforced mortars are not significantly affected by the addition of pig hair.



Asenjo, F. A., & Comisso, L. (2017). Relativistic Magnetic Reconnection in Kerr Spacetime. Phys. Rev. Lett., 118(5), 5 pp.
Abstract: The magnetic reconnection process is analyzed for relativistic magnetohydrodynamical plasmas around rotating black holes. A simple generalization of the SweetParker model is used as a first approximation to the problem. The reconnection rate, as well as other important properties of the reconnection layer, has been calculated taking into account the effect of spacetime curvature. Azimuthal and radial current sheet configurations in the equatorial plane of the black hole have been studied, and the case of small black hole rotation rate has been analyzed. For the azimuthal configuration, it is found that the black hole rotation decreases the reconnection rate. On the other hand, in the radial configuration, it is the gravitational force created by the black hole mass that decreases the reconnection rate. These results establish a fundamental interaction between gravity and magnetic reconnection in astrophysical contexts.



Asenjo, F. A., & Hojman, S. A. (2017). Birefringent light propagation on anisotropic cosmological backgrounds. Phys. Rev. D, 96(4), 12 pp.
Abstract: Exact electromagnetic wave solutions to Maxwell equations on anisotropic Bianchi I cosmological spacetime backgrounds are studied. The waves evolving on Bianchi I spacetimes exhibit birefringence (associated with linear polarization) and dispersion. The particular case of a vacuumdominated anisotropic Universe, which reproduces a FriedmannRobertsonWalker Universe (for late times)while, for earlier times, it matches a Kasner Universeis studied. The electromagnetic waves do not, in general, follow null geodesics. This produces a modification of the cosmological redshift, which is then dependent on light polarization, its dispersion, and its nonnull geodesic behavior. New results presented here may help to tackle some issues related to the “horizon” problem.



Asenjo, F. A., & Hojman, S. A. (2017). Class of Exact Solutions for a Cosmological Model of Unified Gravitational and Quintessence Fields. Found. Phys., 47(7), 887–896.
Abstract: A new approach to tackle Einstein equations for an isotropic and homogeneous FriedmannRobertsonWalker Universe in the presence of a quintessence scalar field is devised. It provides a way to get a simple exact solution to these equations. This solution determines the quintessence potential uniquely and it differs from solutions which have been used to study inflation previously. It relays on a unification of geometry and dark matter implemented through the definition of a functional relation between the scale factor of the Universe and the quintessence field. For a positive curvature Universe, this solution produces perpetual accelerated expansion rate of the Universe, while the Hubble parameter increases abruptly, attains a maximum value and decreases thereafter. The behavior of this cosmological solution is discussed and its main features are displayed. The formalism is extended to include matter and radiation.



Atkinson, J., & Maurelia, A. (2017). RedundancyBased Trust in QuestionAnswering Systems. Computer, 50(1), 58–65.
Abstract: By combining user preferences, redundancy analysis, and trustnetwork inference, the proposed trust model can augment candidate answers with information about target sources on the basis of connections with other web users and sources. Experiments show that the model is more effective overall than trust analyses based on inference alone.



Benitez, S., Duarte, C., Opitz, T., Lagos, N. A., Pulgar, J. M., Vargas, C. A., et al. (2017). Intertidal pool fish Girella laevifrons (Kyphosidae) shown strong physiological homeostasis but shy personality: The cost of living in hypercapnic habitats. Mar. Pollut. Bull., 118(12), 57–63.
Abstract: Tide pools habitats are naturally exposed to a high degree of environmental variability. The consequences of living in these extreme habitats are not well established. In particular, little it is known about of the effects of hypercanic seawater (i.e. high pCO(2) levels) on marine vertebrates such as intertidal pool fish. The aim of this study was to evaluate the effects of increased pCO(2) on the physiology and behavior in juveniles of the intertidal pool fish Girella laevifrons. Two nominal pCO(2) concentrations (400 and 1600 patm) were used. We found that exposure to hypercapnic conditions did not affect oxygen consumption and absorption efficiency. However, the lateralization and boldness behavior was significantly disrupted in high pCO(2) conditions. In general, a predatorrisk cost of boldness is assumed, thus the increased occurrence of shy personality in juvenile fishes may result in a change in the balance of this biological interaction, with significant ecological consequences. (C) 2017 Elsevier Ltd. All rights reserved.



Bunster, C., & Gomberoff, A. (2017). Gravitational domain walls and the dynamics of the gravitational constant G. Phys. Rev. D, 96(2), 9 pp.
Abstract: From the point of view of elementary particle physics the gravitational constant G is extraordinarily small. This has led to ask whether it could have decayed to its present value from an initial one commensurate with microscopical units. A mechanism that leads to such a decay is proposed herein. It is based on assuming that G may take different values within regions of the universe separated by a novel kind of domain wall, a “Gwall”. The idea is implemented by introducing a gauge potential A, and its conjugate D, which determines the value of G as an integration constant rather than a fundamental constant. The value of G jumps when one goes through a Gwall. The procedure extends one previously developed for the cosmological constant, but the generalization is far from straightforward: (i) The intrinsic geometry of a Gwall is not the same as seen from its two sides, because the second law of black hole thermodynamics mandates that the jump in G must cause a discontinuity in the scale of length. (ii) The size of the decay step in G is controlled by a function G(D) which may be chosen so as to diminish the value of G towards the asymptote G = 0, without fine tuning. It is shown that: (i) The dynamics of the gravitational field with G treated as a dynamical variable, coupled to Gwalls and matter, follows from an action principle, which is given. (ii) A particle that impinges on a Gwall may be refracted or reflected. (iii) The various forces between two particles change when a Gwall is inserted in between them. (iv) Gwalls may be nucleated trough tunneling and thermal effects. The semiclassical probabilities are evaluated. (v) If the action principle is constructed properly, the entropy of a black hole increases when the value of the gravitational constant is changed through the absorption of a Gwall by the hole.



Caceres, C., Moffat, R., & Pakalnis, R. (2017). Evaluation of flexural failure of sill mats using classical beam theory and numerical models. Int. J. Rock Mech. Min. Sci., 99(Supplement C), 21–27.



Campos, J. L., del Rio, A. V., Pedrouso, A., Raux, P., Giustinianovich, E. A., & MosqueraCorral, A. (2017). Granular biomass floatation: A simple kinetic/stoichiometric explanation. Chem. Eng. J., 311, 63–71.
Abstract: Floatation events are commonly observed in anammox, denitrifying and anaerobic granular systems mostly subjected to overloading conditions. Although several operational strategies have been proposed to avoid floatation of granular biomass, until now, there is no consensus about the conditions responsible for this phenomenon. In the present study, a simple explanation based on kinetic and stoichiometric principles defining the aforementioned processes is provided. The operational zones corresponding to evaluated parameters where risk of floatation exists are defined as a function of substrate concentration in the bulk liquid and the radius of the granule. Moreover, the possible control of biomass floatation by changing the operating temperature was analyzed. Defined operational zones and profiles fit data reported in literature for granular biomass floatation events. From the study the most influencing parameter on floatation occurrence has been identified as the substrate concentration in the bulk media. (C) 2016 Elsevier B.V. All rights reserved.



Canessa, E., & Chaigneau, S. (2017). Response surface methodology for estimating missing values in a pareto genetic algorithm used in parameter design. Ing. Invest., 37(2), 89–98.
Abstract: We present an improved Pareto Genetic Algorithm (PGA), which finds solutions to problems of robust design in multiresponse systems with 4 responses and as many as 10 control and 5 noise factors. Because some response values might not have been obtained in the robust design experiment and are needed in the search process, the PGA uses Response Surface Methodology (RSM) to estimate them. Not only the PGA delivered solutions that adequately adjusted the response means to their target values, and with low variability, but also found more Pareto efficient solutions than a previous version of the PGA. This improvement makes it easier to find solutions that meet the tradeoff among variance reduction, mean adjustment and economic considerations. Furthermore, RSM allows estimating outputs' means and variances in highly nonlinear systems, making the new PGA appropriate for such systems.



Canfora, F. E., Dudal, D., Justo, I. F., Pais, P., SalgadoRebolledo, P., Rosa, L., et al. (2017). Double nonperturbative gluon exchange: An update on the softPomeron contribution to pp scattering. Phys. Rev. C, 96(2), 8 pp.
Abstract: We employ a set of recent, theoretically motivated fits to nonperturbative unquenched gluon propagators to check on how far double gluon exchange can be used to describe the soft sector of pp scattering data (total and differential cross section). In particular, we use the refined GribovZwanziger gluon propagator (as arising from dealing with the Gribov gauge fixing ambiguity) and the massive Cornwalltype gluon propagator (as motivated from DysonSchwinger equations) in conjunction with a perturbative quarkgluon vertex, next to a model based on the nonperturbative quarkgluon MarisTandy vertex, popular from BetheSalpeter descriptions of hadronic bound states. We compare the cross sections arising from these models with older ISR and more recent TOTEM and ATLAS data. The lower the value of total energy root s, the better the results appear to be.



Carreno, A., Aros, A. E., Otero, C., Polanco, R., Gacitua, M., ArratiaPerez, R., et al. (2017). Substituted bidentate and ancillary ligands modulate the bioimaging properties of the classical Re(I) tricarbonyl core with yeasts and bacteria (vol 41, pg 2140, 2017). New J. Chem., 41(7), 2826.



Chandia, O., Linch, W. D., & Vallilo, B. C. (2017). Master symmetry in the AdS(5) x S5 pure spinor string. J. High Energy Phys., (1), 15 pp.
Abstract: We lift the set of classical nonlocal symmetries recently studied by Klose, Loebbert, and Winkler in the context of Z(2) cosecs to the pure spinor description of the superstring in the AdS(5) x S5 background.



Chuaqui, M., Hernandez, R., & Martin, M. J. (2017). Affine and linear invariant families of harmonic mappings. Math. Ann., 367(34), 1099–1122.
Abstract: We study the order of affine and linear invariant families of planar harmonic mappings in the unit disk. By using the famous shear construction of Clunie and SheilSmall, we construct a function to determine the order of the family of mappings with bounded Schwarzian norm. The result shows that finding the order of the class SH of univalent harmonic mappings can be formulated as a question about Schwarzian norm and, in particular, our result shows consistency between the conjectured order of SH and the Schwarzian norm of the harmonic Koebe function.



Concha, P. K., Fierro, O., & Rodriguez, E. K. (2017). InonuWigner contraction and D=2+1 supergravity. Eur. Phys. J. C, 77(1), 18 pp.
Abstract: We present a generalization of the standard InonuWigner contraction by rescaling not only the generators of a Lie superalgebra but also the arbitrary constants appearing in the components of the invariant tensor. The procedure presented here allows one to obtain explicitly the ChernSimons supergravity action of a contracted superalgebra. In particular we show that the Poincare limit can be performed to a D = 2 + 1 (p, q) AdS ChernSimons supergravity in presence of the exotic form. We also construct a newthreedimensional (2, 0) Maxwell ChernSimons supergravity theory as a particular limit of (2, 0) AdSLorentz supergravity theory. The generalization for N = p + q gravitinos is also considered.



Concha, P. K., Merino, N., & Rodriguez, E. K. (2017). Lovelock gravities from BornInfeld gravity theory. Phys. Lett. B, 765, 395–401.
Abstract: We present a BornInfeld gravity theory based on generalizations of Maxwell symmetries denoted as Cm. We analyze different configuration limits allowing to recover diverse Lovelock gravity actions in six dimensions. Further, the generalization to higher even dimensions is also considered. (C) 2016 The Authors. Published by Elsevier B.V.

