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Effect of 130 keV pulsed electron irradiation on the efficiency of radiative transitions in Eu-doped glass-ceramics CaSiO3
No full textThis work was carried out with partial financial support from Fundaçăo de Amparo à Pesquisa do Estado de Săo Paulo - FAPESP, Brazil (Process number 2014/03085–0 ). To Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq, Brazil , for fellowship to C.D. Gonzales-Lorenzo (Process number 162741/2015–4 ). The authors would like to express our thanks to Dr. H. Loro from the National Engineering University (UNI), Peru, for allowing us to use the appropriate equipment for optical absorption measurements. Besides, C.D. Gonzales-Lorenzo kindly acknowledges the partial financial support from Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica (CONCYTEC) - Banco Mundial , through its executing unit FONDECYT , Peru (Process number 037-2019-FONDECYT-BM-INC.INV.). A.F. Zatsepin and A.N. Kiryakov were supported by the Russian Science Foundation (Grant N° 21-12-00392 ) and also the Russian Foundation for Basic Research-RFBR grants N° 20-42-660012 .Polycrystalline glass-ceramic CaSiO3 doped with Eu3+ ions was obtained by devitrification. The analysis of the photoluminescent characteristics of the obtained glass-ceramic is carried out. It was found that as a result of the devitrification of CaSiO3, two phases are formed, identified as pseudowollastonite (?-CaSiO3) as the dominant phase together with a small percentage of tridymite (SiO2). The UV–Vis optical absorption of Eu3+-doped CaSiO3 was performed using a UV–Vis spectrophotometer. The main objective of this work was to study the effect of the pulsed corpuscular action of electrons accelerated in a field of 130 keV on energy transitions in the Eu3+ ion. It is found that, upon steady-state excitation of the photoluminescent signal in the PLE spectra of unirradiated samples at wavelengths below 300 nm, two broad excitation peaks are displayed, possibly associated with O ? Eu and O ? Si CT transitions. Above 300 nm the characteristic excitation band from 7F0 ground state to 5Hj, 5D4, 5Gj, 5L6, 5D3, and 5D2 states of the Eu3+ ions are shown. It was found that, as a result of exposure to an electron beam in the photoluminescence spectra of europium, a redistribution of the relative intensities of the 5D0 ? 7F2 and 5D0 ? 7F1 transitions occurs. The calculation of the asymmetry ratio of these transitions showed values for an unirradiated sample R21 = 2.06 and irradiated R21 = 2.52, which indicates a decrease in the symmetry of the crystal field around Eu3+ ions after irradiation. Several reasons for the decrease in the relative intensity of the Eu3+ luminescence signal after electron irradiation, caused by the effect of electrization of the material, intrinsic defects of the matrix, and inhomogeneous phase composition, are discussed. © 2021 Elsevier B.V.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Evaluation of GPM Dual-Frequency Precipitation Radar Algorithms to Estimate Drop Size Distribution Parameters, Using Ground-Based Measurement over the Central Andes of Peru
No full textThe present study comes under the project “MAGNET-IGP: Strengthening the research line in physics and microphysics of the atmosphere (Agreement No 010-2017-FONDECYT)”. Yamina Silva-Vidal, Jose Luis Flores-Rojas and Jairo Valdivia-Prado would like to acknowledge the Peruvian PPR068 programme "Reducción de vulnerabilidad y atención de emergencias por desastres" for financial support of their work. This work was done using computational resources, HPC-Linux -Cluster, from Laboratorio de Dinámica de Fluidos Geofísicos Computacionales at Instituto Geofísico del Perú (Grants 101-2014-FONDECYT, SPIRALES2012, IRD-IGP, Manglares IGP-IDRC, PP068 program).The raindrop size distribution (DSD) parameters, which consists of the mass-weighted average diameter (Dm) and the scaling parameter for the concentration (Nw) are essential to estimate precipitation in numerical modelling and other research areas such as the Global Precipitation Measurement (GPM) core satellite. In the present work, we used the GPM Dual-Frequency Precipitation Radar algorithms (GPM-DPR), single (SF) and dual (DF) frequency, and in situ observations to derive the DSD parameters and evaluate the performance of algorithms under the complex orography and climate regime of the central Andes. We used data from optical disdrometer and Ka-band profiler radar over Huancayo Observatory during the austral summer monsoon. Our results indicate that the GPM-DPR algorithms have problems to correctly estimate the DSD parameters of convective rains due to the high variability in time and space of this type of rain and is the result of fixing the shape parameter (µ). The estimation of DSD parameters in stratiform rains, which are very common in the central Andes, is strongly affected by the limitation of the DF algorithm in light rain rates caused by its inability to estimate Dm < 1 mm. © 2021, King Abdulaziz University and Springer Nature Switzerland AG.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Generalized Archimedean spaces and expansivity
No full textRM was partially supported by Fondecyt-Concytec contract 100-2018 , HV was partially supported by Universidad Nacional de Ingeniería FC-PF-33-2021 and P-CC-2021-000666 . CAM was partially supported by CNPq -Brazil and the NRF Brain Pool Grant funded by the Korea government (No. 2020H1D3A2A01085417 ).Roughly speaking, the N-Archimedean spaces for N?N are metric spaces which are the opposite of the classical non-Archimedean ones. We prove that a compact N-Archimedean space has no more than N?1 isolated points, is infinite and (N+1)-Archimedean. Moreover, there are compact (N+1)-Archimedean spaces which are not N-Archimedean for every N?N. Afterwards, we study the dynamics of the expansive systems on N-Archimedean spaces. © 2021 Elsevier B.V.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Geology, mineralogy, and cassiterite geochronology of the Ayawilca Zn-Pb-Ag-In-Sn-Cu deposit, Pasco, Peru
No full textThis study was economically supported by the Peruvian CONCYTEC-FONDECYT-World Bank project 107-2018-FONDECYT-BM-IADT-AV and the Mexican research program CONACYT-Ciencia Básica (A1-S-14574). We thank the staff of Tinka Resources Ltd., particularly to Jorge Gamarra, for help and hospitality during the sampling program. We appreciate the technical support by Xavier Llovet (CCiT-UB) and Carlos Ortega Obregón (LEI-UNAM) during acquisition of EPMA data, and by Pete Tollan (ETH) during acquisition of LA-ICP-MS data. We are grateful to Richard Sillitoe, Andreas Dietrich, Graham Carman (president and CEO of Tinka Resources), and Editor-in-Chief Bernd Lehmann for their constructive comments which significantly improved the manuscript. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.The Ayawilca deposit in Pasco, Peru, represents the most significant recent base-metal discovery in the central Andes and one of the largest undeveloped In resources globally. As of 2018, it hosts an 11.7 Mt indicated resource grading 6.9% Zn, 0.16% Pb, 15 g/t Ag, and 84 g/t In, an additional 45.0 Mt inferred resource grading 5.6% Zn, 0.23% Pb, 17 g/t Ag, and 67 g/t In, and a separate Sn-Cu-Ag inferred resource of 14.5 Mt grading 0.63% Sn, 0.21% Cu, and 18 g/t Ag. Newly obtained U–Pb dates for cassiterite by LA-ICP-MS (22.77 ± 0.41 and 23.05 ± 2.06 Ma) assign the Ayawilca deposit to the Miocene polymetallic belt of central Peru. The polymetallic mineralization occurs as up to 70-m-thick mantos hosted by carbonate rocks of the Late Triassic to Early Jurassic Pucará Group, and subordinately, as steeply dipping veins hosted by rocks of the Pucará Group and overlying Cretaceous sandstones-siltstones of the Goyllarisquizga Group. Relicts of a distal retrograde magnesian skarn and cassiterite (stage pre-A) were identified in the deepest mantos. The volumetrically most important mineralization at Ayawilca comprises a low-sulfidation assemblage (stage A) with quartz, pyrrhotite, arsenopyrite, chalcopyrite, Fe-rich sphalerite, and traces of stannite and herzenbergite. Stage A sphalerite records progressive Fe depletion, from 33 to 10 mol% FeS, which is compatible with the observed transition from low- to a subsequent intermediate-sulfidation stage (B) marked by the crystallization of abundant pyrite and marcasite. Finally, during a later intermediate-sulfidation stage (C) sphalerite (up to 11 mol% FeS), galena, native bismuth, Cu-Pb-Ag sulfosalts, siderite, Mn-Fe carbonates, kaolinite, dickite, and sericite were deposited. This paragenetic evolution shows striking similarities with that at the Cerro de Pasco Cordilleran-type polymetallic deposit, even if at Ayawilca stage C did not reach high-sulfidation conditions. The occurrence of an early retrograde skarn assemblage suggests that the manto bodies at Ayawilca formed at the transition between distal skarn and skarn-free (Cordilleran-type) carbonate-replacement mineralization. Mineral assemblages define a T-fS2 evolutionary path close to the pyrrhotite-pyrite boundary. Buffering of hydrothermal fluids by underlying Devonian carbonaceous phyllites of the Excelsior Group imposed highly reduced conditions during stage A mineralization (logfO2 < ? 30 atm). The low fO2 favored efficient Sn mobility during stages pre-A and A, in contrast to other known ore deposits in the polymetallic belt of central Peru, in which the occurrence of Sn minerals is minor. Subsequent cooling, progressive sealing of vein walls, and decreasing buffering potential of the host rocks promoted the shift from low- (stage A) to intermediate-sulfidation (stages B and C) states. LA-ICP-MS analyses reveal significant In contents in Fe-rich sphalerite (up to 1.7 wt%), stannite (up to 1908 ppm), and chalcopyrite (up to 1185 ppm). The highest In content was found in stage A sphalerite that precipitated along with chalcopyrite and stannite, thus pointing to the early, low-sulfidation assemblage as prospective for this high-tech metal in similar mineral systems. Indium was likely incorporated into the sphalerite crystal lattice via Cu+ + In3+ ? 2 Zn2+ and (Sn, Ge)4+ + (Ga, In)3+ + (Cu + Ag)+ ? 4 Zn2+ coupled substitutions. Indium incorporation mechanisms into the stannite and chalcopyrite crystal lattices remain unclear. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Simulation with a conceptual distributed hydrological model on a daily scale in a semi-arid basin of the lurin river, Peru [Simulación con un modelo hidrológico distribuido de tipo conceptual a escala diaria en una cuenca semiárida del río Lurín, Perú]
No full textEste trabajo fue financiado por el CONCYTECFONDECYT en el marco de la convocatoria Proyecto Investigaci?n B?sica y Aplicada, 2017-02 [Convenio N? 157-2017-FONDECYT].The Lurin river is located in the coastal part of Peru. Although, in general the climate is arid, in some month of the year in possible to have some precipitation. This situation is the main cause of deficits in water resources management, inefficient growth of agriculture and livestock, lack of climatic and hydrometric information in the Basin. The TETIS Model which is a spatially distributed hydrological has been applied to modeling the Lurín river basin, for which information on precipitation, evapotranspiration and flow, geomorphological maps (MED, accumulated cells, flow direction, slope, speed), maps of hydrological parameters of static storage (Hu) and hydraulic conductivity of the soil (Ks) and the map of hydraulic conductivity of the aquifer (Kp), the map of vegetation cover and the information referred to the index of vegetation (?) by type of cover. In the hydrometric station of Antapucro and San Damian, the daily calibration and validation of the model were carried out. Obtaining the Nash indices (NSE), normalized mean square error (RSR) and volume error (Ev) of (0.7551, 0.4949, 0.701%) for calibration and (0.7611, 0.4888, –14.629%) for validation, respectively; the parameters with the highest sensitivity in the model being the evapotranspiration correction factor (FC2) and the rain interpolation factor (?). The daily flows were simulated from 1969 to 2019, the annual water balance an offer of 121.36 hm3 and demand of 111.59 hm3 were obtained, which corresponds mainly to agricultural use. In the water balance there is a surplus from January to May of 58.44 hm3, which is discharged to the sea due to the inexistent reservoir infrastructure in the basin. In the others months, June to December, there is a deficit of 48.67 hm3 due to the lack of rain. © 2021, Universidad de Tarapaca. All rights reserved.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
The reversibility property in a job-insertion tiebreaker for the permutational flow shop scheduling problem
No full textWe are indebted to Profs. Victor Fernandez-Viagas and Weibo Liu for generously sharing their code and for guiding us on the reimplementation of their tiebreakers. We are very grateful to the referees, for their valuable comments on earlier versions of this paper. This research has been partially supported by the Fondo Nacional de Desarrollo Cient?fico, Tecnol?gico y de Innovaci?n Tecnol?gica (FONDECYT) and the World Bank through projects Kusisqa (014/2019 - FONDECYT - BM - INC.INV) and Het-FSSP (445/2019 - FONDECYT - PIB); and by the supercomputing center ?Inkari? of the Universidad Nacional de San Agust?n de Arequipa.The best performing approximate methods proposed for the permutational flow shop scheduling problem with makespan minimization are the well known NEH constructive heuristic and the iterated greedy algorithm. Both methods are based on the successive insertion (or reinsertion) of jobs into a partial schedule, evaluating the makespan of the resulting schedule for all insertion positions, and selecting the insertion position that presents the shortest makespan. Frequently, there are many tied insertion positions that produce such shortest makespan. Thus, a tiebreaker must be used to discern a selection among the tied insertion positions. Many tiebreakers have been proposed in the literature for this case. These tiebreakers improve the results produced by approximate methods when embedded into them. In this paper we propose two new tiebreakers that use a weighted and an unweighted approximation of the idle time increment produced by inserting the job into each tied insertion position. They were designed considering the reversibility property of the PFSSP. Our computational experiments show that the proposed tiebreakers outperform tiebreakers from the literature when evaluated within the NEH heuristic and within the iterated greedy algorithm. The iterated greedy algorithms with the proposed tiebreakers embedded are the best approximate methods so far for the permutational flow shop scheduling problem. © 2021 Elsevier B.V.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Topological stability for fuzzy expansive maps
No full textThe authors would like to thank Carlos A. Morales, for useful talks on the subject of expansiveness and shadowing. Also, the authors would like to thank Professor H. Miranda and the anonymous reviewers for their valuable comments that helped to improve the final version of the article. The first author was partially supported by CONICYT PFCHA/DOCTORADO NACIONAL/2017-21170110 and Agencia Nacional de Investigaci?n y Desarrollo-ANID, Chile, project FONDECYT 1181061. The second author was partially supported by Agencia Nacional de Investigaci?n y Desarrollo-ANID, Chile, project FONDECYT 1181061, by Universidad del B?o-B?o, Chile, project 196108 GI/C, and by Programa do Postdoutorado Ver?o 2017-2019, IMPA, Rio de Janeiro, Brasil. The last author was partially supported by FONDECYT (Per?) contract 100?2018.We introduce the definitions of expansivity and topological stability for homeomorphisms on fuzzy metric spaces. We show some basic properties of fuzzy expansive homeomorphisms. Moreover we prove Walters's theorem in the context of fuzzy metric spaces, i.e., a fuzzy expansive system with the fuzzy shadowing property is fuzzy topologically stable.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Trophic interactions and metal transfer in marine ecosystems driven by the Peruvian scallop Argopecten purpuratus aquaculture
No full textConsejo Nacional de Ciencia, Tecnología e Innovación Tecnológica (CONCYTEC), Grant/Award Number: 214‐2015‐FONDECYT; Fonds Wetenschappelijk Onderzoek, Grant/Award Number: GOH3817N Funding informationThis study investigates the trophic interactions and As and Cd transfer along seven marine ecosystems in Peru. Five of these ecosystems are driven by aquaculture of the Peruvian scallop Argopecten purpuratus. A southward increased gradient of δ15N was observed among the three examined regions along the Peruvian coast. The stable isotope analysis in R (SIAR)-stable isotope mixing models helped to clarify the feeding ecology of A. purpuratus and its important predators (e.g., Bursa ventricosa, Romaleon setosum). The food items of A. purpuratus can be ranked in decreasing order of importance: seston > sediment > particulate organic matter (POM) > brackish-and-fresh water POM input, while A. purpuratus itself was found to be the main prey item for predators. The highest trophic magnification factors (TMFs) were 1.46 and 1.07 for As and Cd, respectively, and were both found at the location in front of the Illescas Reserve Zone (northern Peru). Metal biomagnification and non-biomagnification effects were found in the Peruvian marine food webs, but A. purpuratus always fitted the trophic metal magnification or bio-dilution regression model as intermediate consumer and/or prey. The TMFs and linear metal relationships implied that As contamination is a serious concern in marine ecosystems in Peru. © 2021 The Authors. Journal of the World Aquaculture Society published by Wiley Periodicals LLC on behalf of World Aquaculture Society.Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concyte
Characterization of the Enterobacteriaceae-associated ROD21-like family of excisable genomic islands and study of excision in the pathogenicity island ROD21
No full textThe results of this thesis expand the repertory of identified excisable genomic islands, presenting insights about their evolution, and provide a first approach to the understanding of the regulation of excision in the pathogenicity island ROD21. These findings may contribute to the better understanding of current and emerging pathogens such as Salmonella serovars, pathogenic E. coli and carbapenem-resistant K. pneumoniae ST258, among others
Potencialidades y limitaciones de las alianzas público privadas para el desarrollo desde la perspectiva de los agentes involucrados: la experiencia peruana
No full textTrata de contribuir a la construcción de esquemas y mecanismos que ayuden a erradicar la pobreza en el mundo. La investigación, se fundamenta en el análisis de la información recogida de los potenciales agentes que podrían conformar una Alianza Publica Privada para el Desarrollo (APPD) en Perú, mediante la realización de encuestas, entrevistas y un taller de validación. Además,se analizan casos de APPD ejecutados en Perú, con la finalidad de extraer sus principales lecciones. Al analizar los resultados, observamos que los agentes manifiestan tener recursos financieros para la ejecución de una APPD, y que cuentan con herramientas para aplicarlas. Las conclusiones corroboran que el concepto de APPD aún está en construcción, denotando así, el escaso nivel de conocimiento del mecanismo por parte de los potenciales agentes, sin embargo, se ha comprobado el interés por aplicar el mecanismo en Perú