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Author Asenjo, F.A.; Hojman, S.A. doi  openurl
  Title Birefringent light propagation on anisotropic cosmological backgrounds Type Journal Article
  Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 96 Issue 4 Pages 12 pp  
  Keywords  
  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 vacuum-dominated anisotropic Universe, which reproduces a Friedmann-Robertson-Walker Universe (for late times)-while, for earlier times, it matches a Kasner Universe-is 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 non-null geodesic behavior. New results presented here may help to tackle some issues related to the “horizon” problem.  
  Address [Asenjo, Felipe A.; Hojman, Sergio A.] Univ Adolfo Ibanez, UAI Phys Ctr, Santiago 7941169, Chile, Email: felipe.asenjo@uai.cl;  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0010 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407716200007 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 756  
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Author Canessa, E.; Chaigneau, S. doi  openurl
  Title Response surface methodology for estimating missing values in a pareto genetic algorithm used in parameter design Type Journal Article
  Year 2017 Publication Ingenieria E Investigacion Abbreviated Journal Ing. Invest.  
  Volume 37 Issue 2 Pages 89-98  
  Keywords Robust design; parameter design; pareto genetic algorithm; response surface methodology  
  Abstract We present an improved Pareto Genetic Algorithm (PGA), which finds solutions to problems of robust design in multi-response 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 trade-off among variance reduction, mean adjustment and economic considerations. Furthermore, RSM allows estimating outputs' means and variances in highly non-linear systems, making the new PGA appropriate for such systems.  
  Address [Canessa, Enrique] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Santiago, Chile, Email: ecanessa@uai.cl;  
  Corporate Author Thesis  
  Publisher Univ Nac Colombia, Fac Ingenieria Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0120-5609 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000408441100012 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 760  
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Author Canfora, F.E.; Dudal, D.; Justo, I.F.; Pais, P.; Salgado-Rebolledo, P.; Rosa, L.; Vercauteren, D. doi  openurl
  Title Double nonperturbative gluon exchange: An update on the soft-Pomeron contribution to pp scattering Type Journal Article
  Year 2017 Publication Physical Review C Abbreviated Journal Phys. Rev. C  
  Volume 96 Issue 2 Pages 8 pp  
  Keywords  
  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 Gribov-Zwanziger gluon propagator (as arising from dealing with the Gribov gauge fixing ambiguity) and the massive Cornwall-type gluon propagator (as motivated from Dyson-Schwinger equations) in conjunction with a perturbative quark-gluon vertex, next to a model based on the nonperturbative quark-gluon Maris-Tandy vertex, popular from Bethe-Salpeter 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.  
  Address [Canfora, F. E.; Pais, P.] Ctr Estudios Cient, Casilla 1469, Valdivia, Chile, Email: fcanforat@gmail.com;  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9985 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407017900004 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 751  
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Author Ekman, R.; Asenjo, F.A.; Zamanian, J. doi  openurl
  Title Relativistic kinetic equation for spin-1/2 particles in the long-scale-length approximation Type Journal Article
  Year 2017 Publication Physical Review E Abbreviated Journal Phys. Rev. E  
  Volume 96 Issue 2 Pages 8 pp  
  Keywords  
  Abstract In this paper, we derive a fully relativistic kinetic theory for spin-1/2 particles and its coupling to Maxwell's equations, valid in the long-scale-length limit, where the fields vary on a scale much longer than the localization of the particles; we work to first order in (h) over bar. Our starting point is a Foldy-Wouthuysen (FW) transformation, applicable to this regime, of the Dirac Hamiltonian. We derive the corresponding evolution equation for the Wigner quasidistribution in an external electromagnetic field. Using a Lagrangian method we find expressions for the charge and current densities, expressed as free and bound parts. It is furthermore found that the velocity is nontrivially related to the momentum variable, with the difference depending on the spin and the external electromagnetic fields. This fact that has previously been discussed as “hidden momentum” and is due to that the FW transformation maps pointlike particles to particle clouds for which the prescription of minimal coupling is incorrect, as they have multipole moments. We express energy and momentum conservation for the system of particles and the electromagnetic field, and discuss our results in the context of the Abraham-Minkowski dilemma.  
  Address [Ekman, R.; Zamanian, J.] Umea Univ, Dept Phys, SE-90187 Umea, Sweden  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2470-0045 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000408118100012 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 759  
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Author Filker, S.; Forster, D.; Weinisch, L.; Mora-Ruiz, M.; Gonzalez, B.; Farias, M.E.; Rossello-Mora, R.; Stoeck, T. doi  openurl
  Title Transition boundaries for protistan species turnover in hypersaline waters of different biogeographic regions Type Journal Article
  Year 2017 Publication Environmental Microbiology Abbreviated Journal Environ. Microbiol.  
  Volume 19 Issue 8 Pages 3186-3200  
  Keywords  
  Abstract The identification of environmental barriers which govern species distribution is a fundamental concern in ecology. Even though salt was previously identified as a major transition boundary for micro- and macroorganisms alike, the salinities causing species turnover in protistan communities are unknown. We investigated 4.5 million high-quality protistan metabarcodes (V4 region of the SSU rDNA) obtained from 24 shallow salt ponds (salinities 4%-44%) from South America and Europe. Statistical analyses of protistan community profiles identified four salinity classes, which strongly selected for different protistan communities: 4-9%, 14-24%, 27-36% and 38-44%. The proportion of organisms unknown to science is highest in the 14-24% salinity class, showing that environments within this salinity range are an unappreciated reservoir of as yet undiscovered organisms. Distinct higher-rank taxon groups dominated in the four salinity classes in terms of diversity. As increasing salinities require different cellular responses to cope with salt, our results suggest that different evolutionary lineages of protists have evolved distinct haloadaptation strategies. Salinity appears to be a stronger selection factor for the structuring of protistan communities than geography. Yet, we find a higher degree of endemism in shallow salt ponds compared with less isolated ecosystems such as the open ocean. Thus, rules for biogeographic structuring of protistan communities are not universal, but depend on the ecosystem under consideration.  
  Address [Filker, Sabine] Univ Kaiserslautern, Dept Mol Ecol, D-67663 Kaiserslautern, Germany, Email: stoeck@rhrk.uni-kl.de  
  Corporate Author Thesis  
  Publisher Wiley Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1462-2912 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407790700021 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 761  
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Author Garcia, J.; Pope, C.; Altimiras, F. doi  openurl
  Title A Distributed K-Means Segmentation Algorithm Applied to Lobesia botrana Recognition Type Journal Article
  Year 2017 Publication Complexity Abbreviated Journal Complexity  
  Volume Issue Pages 14 pp  
  Keywords  
  Abstract Early detection of Lobesia botrana is a primary issue for a proper control of this insect considered as the major pest in grapevine. In this article, we propose a novel method for L. botrana recognition using image data mining based on clustering segmentation with descriptors which consider gray scale values and gradient in each segment. This system allows a 95 percent of L. botrana recognition in non-fully controlled lighting, zoom, and orientation environments. Our image capture application is currently implemented in a mobile application and subsequent segmentation processing is done in the cloud.  
  Address [Garcia, Jose; Pope, Christopher; Altimiras, Francisco] Telefon Invest & Desarrollo, Santiago, Chile, Email: joseantonio.garcia@telefonica.com  
  Corporate Author Thesis  
  Publisher Wiley-Hindawi Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1076-2787 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407198000001 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 754  
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Author Garmendia, M.L.; Mondschein, S.; Matus, O.; Murrugarra, R.; Uauy, R. doi  openurl
  Title Predictors of gestational weight gain among Chilean pregnant women: The Chilean Maternal and Infant Nutrition Cohort study Type Journal Article
  Year 2017 Publication Health Care For Women International Abbreviated Journal Health Care Women Int.  
  Volume 38 Issue 8 Pages 892-904  
  Keywords  
  Abstract We identified factors associated with gestational weight gain (GWG) in 1,654 Chilean pregnant women with full-term pregnancies. At baseline, we collected information about sociodemographic, gyneco-obstetric, anthropometric, and health-care-related factors. We found that prepregnancy nutritional body mass index was the most important factor related to GWG above recommendations (overweight: ratio of relative risks [RRR] = 2.31, 95% confidence interval [CI, 1.73, 3.09] and obesity: RRR = 2.90, 95% CI [2.08, 4.03]). We believe that women who are overweight/obese at the beginning of pregnancy should be identified because of their higher risk, and that adequate strategies should be designed and implemented to help them achieve a healthy GWG.  
  Address [Luisa Garmendia, Maria; Uauy, Ricardo] Univ Chile, Inst Nutr & Food Technol, Libano 5524, Santiago, Chile, Email: mgarmendia@inta.uchile.cl  
  Corporate Author Thesis  
  Publisher Taylor & Francis Inc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0739-9332 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407518400009 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 758  
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Author Ljubic, I.; Moreno, E. doi  openurl
  Title Outer approximation and submodular cuts for maximum capture facility location problems with random utilities Type Journal Article
  Year 2017 Publication European Journal Of Operational Research Abbreviated Journal Eur. J. Oper. Res.  
  Volume to appear Issue Pages  
  Keywords  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0377-2217 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 762  
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Author Munoz, F.D.; Pumarino, B.J.; Salas, I.A. pdf  doi
openurl 
  Title Aiming low and achieving it: A long-term analysis of a renewable policy in Chile Type Journal Article
  Year 2017 Publication Energy Economics Abbreviated Journal Energy Econ.  
  Volume 65 Issue Pages 304-314  
  Keywords Planning model; Renewable portfolio standard; Renewable energy certificates  
  Abstract We use an Integrated Resource Planning model to assess the costs of meeting a 70% renewables target by 2050 in Chile. This model is equivalent to a long-term equilibrium in electricity and renewable energy certificate (REC) markets under perfect competition. We consider different scenarios of demand growth, resource eligibility (e.g., large hydropower), and transmission system configuration. Our numerical results indicate that the sole characteristics of the available renewable resources in the country and reductions in technology costs will provide sufficient economic incentives for private investors to supply a fraction of renewables larger than 70% for a broad range of scenarios, meaning that the proposed target will likely remain a symbolic government effort. Increasing transmission capacity between the northern and central interconnected systems could reduce total system cost by $400 million per year and increase the equilibrium share of non conventional renewable energy (NCRE) in the system from 45% to 52%, without the need for any additional policy incentive. Surprisingly, imposing a 70% of NCRE by 2050 results in a REC price lower than the noncompliance fine used for the current target of 20% of NCRE by 2025, the latter of which represents the country's maximum willingness to pay for the attributes of electricity supplied from NCRE resources. (C) 2017 Elsevier B.V. All rights reserved.  
  Address [Munoz, Francisco D.; Pumarino, Bruno J.; Salas, Ignacio A.] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Diagonal Torres 2640,Oficina 303D, Santiago, Chile, Email: fdmunoz@uai.cl  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0140-9883 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000406731900028 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 753  
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Author Nasirov, S.; Agostini, C.A.; Silva, C. doi  openurl
  Title An assessment of the implementation of renewable energy sources in the light of concerns over Chilean policy objectives Type Journal Article
  Year 2017 Publication Energy Sources Part B-Economics Planning And Policy Abbreviated Journal Energy Sources Part B  
  Volume 12 Issue 8 Pages 715-721  
  Keywords Chile; MCDA; policy objectives; renewable energy; sensitivity analysis  
  Abstract In recent years, the development of renewable energies in the electricity market in Chile has gained significant attention as a key alternative for energy sources diversification and meeting three key policy objectives: energy availability, environmental protection, and social-economic development. This study aims to assess various renewable energy sources in order to select suitable sources to accomplish the different policy goals in a country like Chile. For this purpose, a Multi-Criteria Decision Analysis (MCDA) method is employed to evaluate the relative importance of policy objectives. In addition, a sensitivity analysis is conducted to build various different policy scenarios measuring the impact of variations on the current weights of the decision criteria. The results show that solar, wind, and small hydro are the preferred sources in the Chilean renewable energy portfolio, maximizing the objective of meeting the three policy goals at the same time.  
  Address [Nasirov, Shahriyar; Silva, Carlos] Univ Adolfo Ibanez, Fac Ingn & Ciencias, Ave Diagonal Torres 2640, Santiago, Chile, Email: shahriyar.nasirov@uai.cl  
  Corporate Author Thesis  
  Publisher Taylor & Francis Inc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1556-7249 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407930900006 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 757  
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Author Pedrouso, A.; del Rio, A.V.; Morales, N.; Vazquez-Padin, J.R.; Campos, J.L.; Mendez, R.; Mosquera-Corral, A. doi  openurl
  Title Nitrite oxidizing bacteria suppression based on in-situ free nitrous acid production at mainstream conditions Type Journal Article
  Year 2017 Publication Separation And Purification Technology Abbreviated Journal Sep. Purif. Technol.  
  Volume 186 Issue Pages 55-62  
  Keywords Ammonium oxidizing bacteria; Flocculent sludge; Free nitrous acid; Mainstream; Nitrite oxidizing bacteria; Partial nitritation  
  Abstract The application of autotrophic nitrogen removal processes in the main line of wastewater treatment plants will contribute to achieve its self-energy-sufficiency. However, the effective suppression of nitrite oxidizing bacteria (NOB) activity at the conditions of low temperature and low ammonium concentration (mainstream conditions) was identified as one of the main bottlenecks. In this study, stable partial nitritation at 16 degrees C and 50 mg NH4+-N/L was achieved maintaining inside the reactor free nitrous acid (FNA) concentrations inhibitory for NOB (>0.02 mg HNO2-N/L), without dissolved oxygen concentration control, The FNA inhibitory concentration was generated by the partial nitritation process, and its stimulation was studied with two different inhibitors: sodium azide and nitrite. The microbiological analysis revealed that, throughout the operational period with inhibitory FNA levels, the NOB populations (dominated by Nitrospira) were effectively washed out from the reactor. This is an advantage that allowed maintaining a good stability of the process, even when the FNA concentration was not enough to inhibit the NOB, taking about 40 days to develop significant activity. The observed delay on the NOB development is expected to enable the establishment of corrective actions to avoid the partial nitritation destabilization. The use of the FNA to achieve a stable partial nitritation process is recommended to profit from the natural pH decrease associated to the nitritation process and from its favoured accumulation at low temperatures as those from the mainstream. In this research study an analysis about the influence of ammonium and alkalinity concentrations was also performed to know in which scenarios the FNA inhibitory concentration can be achieved. (C) 2017 Elsevier B.V. All rights reserved.  
  Address [Pedrouso, Alba; del Rio, Angeles Val; Mendez, Ramon; Mosquera-Corral, Anuska] Univ Santiago de Compostela, Sch Engn, Dept Chem Engn, E-15705 Santiago De Compostela, Spain, Email: alba.pedrouso@usc.es;  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1383-5866 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000406730700007 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 755  
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Author Slane, J.; Vivanco, J.F.; Squire, M.; Ploeg, H.L. doi  openurl
  Title Characterization of the quasi-static and viscoelastic properties of orthopaedic bone cement at the macro and nanoscale Type Journal Article
  Year 2017 Publication Journal Of Biomedical Materials Research Part B-Applied Biomaterials Abbreviated Journal J. Biomed. Mater. Res. Part B  
  Volume 105 Issue 6 Pages 1461-1468  
  Keywords bone cement; nanoindentation; mechanical testing; creep; orthopaedics  
  Abstract Acrylic bone cement is often used in total joint replacement procedures to anchor an orthopaedic implant to bone. Bone cement is a viscoelastic material that exhibits creep and stress relaxation properties, which have been previously characterized using a variety of techniques such as flexural testing. Nanoindentation has become a popular method to characterize polymer mechanical properties at the nanoscale due to the technique's high sensitivity and the small sample volume required for testing. The purpose of the present work therefore was to determine the mechanical properties of bone cement using traditional macroscale techniques and compare the results to those obtained from nanoindentation. To this end, the quasi-static and viscoelastic properties of two commercially available cements, Palacos and Simplex, were assessed using a combination of three-point bending and nanoindentation. Quasi-static properties obtained from nanoindentation tended to be higher relative to three-point bending. The general displacement and creep compliance trends were similar for the two methods. These findings suggest that nanoindentation is an attractive characterization technique for bone cement, due to the small sample volumes required for testing. This may prove particularly useful in testing failed/ retrieved cement samples from patients where material availability is typically limited. (C) 2016 Wiley Periodicals, Inc.  
  Address [Slane, Josh] Katholieke Univ Leuven, Univ Hosp Leuven, Inst Orthopaed Res & Training, Pellenberg, Belgium, Email: joshua.slane@kuleuven.be  
  Corporate Author Thesis  
  Publisher Wiley Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1552-4973 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000407055400016 Approved no  
  Call Number UAI @ eduardo.moreno @ Serial 752  
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