3.1 Estancias en cooperación internacional

URI permanente para esta colección

https://hdl.handle.net/20.500.12390/3674

Examinar

Examinando 3.1 Estancias en cooperación internacional por Título

  • Publicación
    A new species of the genus Neotropiella Handschin, 1942 (Collembola: Neanuridae) from Peru
    (Pensoft Publishers, 2020)
    Palacios-Vargas J.G.
    ;
    Callohuari Y.T.
    Background: Neotropiella is a genus of springtails which can be of medium size (2 mm) or relatively long (5 mm). These springtails live in leaf litter, under the bark of dead trees or in decomposing wood, mainly in the Neotropical Region and are often collected by litter samples on Berlese funnels or by pitfall traps. Most species have been described, based on relatively few specimens and chaetotaxy of several species is incomplete. New information: A new species within Neotropiella was discovered in recent pitfall trap collections from Peru. Neotropiella peruana sp. n. was taxonomically treated and studied under both phase contrast and scanning electron microscopy. It is similar to N. insularis from Brazil, but smaller with only 4 mandibular teeth (vs. 5) and with well-developed unguis lateral teeth. Intraspecific variation of the new species is provided. We also present the first DNA barcodes for the genus. © 2020 Palacios-Vargas J, Callohuari Y. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. All Rights Reserved.
  • Publicación
    A numerical algorithm for finding solutions of a generalized Nash equilibrium problem
    (Springer Nature, 2012)
    Matioli L.C.
    ;
    Sosa W.
    ;
    Yuan J.
    A family of nonempty closed convex sets is built by using the data of the Generalized Nash equilibrium problem (GNEP). The sets are selected iteratively such that the intersection of the selected sets contains solutions of the GNEP. The algorithm introduced by Iusem-Sosa (Optimization 52:301–316, 2003) is adapted to obtain solutions of the GNEP. Finally some numerical experiments are given to illustrate the numerical behavior of the algorithm.
  • Publicación
    Band-fluctuations model for the fundamental absorption of crystalline and amorphous semiconductors: A dimensionless joint density of states analysis
    (Institute of Physics Publishing, 2019)
    Guerra Torres, Jorge Andrés
    ;
    Tejada A.
    ;
    Töfflinger J.A.
    ;
    Grieseler R.
    ;
    Korte L.
    We develop a band-fluctuations model which describes the absorption coefficient in the fundamental absorption region for direct and indirect electronic transitions in disordered semiconductor materials. The model accurately describes both the Urbach tail and absorption edge regions observed in such materials near the mobility edge in a single equation with only three fitting parameters. An asymptotic analysis leads to the universally observed exponential tail below the bandgap energy and to the absorption edge model at zero Kelvin above it, for either direct or indirect electronic transitions. The latter feature allows the discrimination between the absorption edge and absorption tails, thus yielding more accurate bandgap values when fitting optical absorption data. We examine the general character of the model using a dimensionless joint density of states formalism with a quantitative analysis of a large amount of optical absorption data. Both heavily doped p-type GaAs and nano-crystalline Ga 1-x Mn x N, as examples for direct bandgap materials, as well as amorphous Si:H x , SiC:H x and SiN x , are modeled successfully with this approach. We contrast our model with previously reported empirical models, showing in our case a suitable absorption coefficient shape capable of describing various distinct materials while also maintaining the universality of the exponential absorption tail and absorption edge. © 2019 IOP Publishing Ltd.
  • Publicación
    CALLISTO facilities in Peru: spectrometer commissioning and observations of type III solar radio bursts
    (NATL ASTRONOMICAL OBSERVATORIES, CHIN ACAD SCIENCES, 2021)
    Alonso Rengifo, Javier
    ;
    Loaiza-Tacuri, Veronica
    ;
    Bazo, Jose
    ;
    Guevara Day, Walter Robert
    The Astrophysics Directorate of CONIDA has installed two radio spectrometer stations belonging to the e-CALLISTO network in Lima, Peru. Given their strategic location near the Equator, it is possible to observe the Sun evenly throughout the whole year. The receiver located at Pucusana, nearby the capital city of Lima, took data from October 2014 until August 2016 in the metric and decimetric bands looking for radio bursts. During this period, this e-CALLISTO detector was unique in its time-zone coverage. To asses the suitability of the sites and the performance of the antennas, we analyzed the radio ambient background and measured their radiation pattern and beamwidth. To demonstrate the capabilities of the facilities for studying solar dynamics in these radio frequencies, we have selected and analyzed type III Solar Radio Bursts. The study of this kind of burst helps to understand the electron beams traversing the solar corona and the solar atmospheric density. We have characterized the most common radio bursts with the following mean values: a negative drift rate of -25.8 +/- 3.7 MHz s(-1), a duration of 2.6 +/- 0.3 s and 35 MHz bandwidth in the frequency range of 114 to 174 MHz. In addition, for some events, it was possible to calculate a global frequency drift which on average was 0.4 +/- 0.1 MHz s(-1).
  • Publicación
    Case Report: Possible Vertical Transmission of Bartonella bacilliformis in Peru
    (American Society of Tropical Medicine and Hygiene, 2015)
    Tuya, XL
    ;
    Escalante-Kanashiro, R
    ;
    Tinco, C
    ;
    Pons, MJ
    ;
    Petrozzi, V
    ;
    Ruiz, J
    ;
    del Valle, J
    A 22-day-old male was admitted with a 2-day history of irritability, dyspnea, jaundice, fever, and gastroin testinal bleeding. A thin blood smear was performed, which showed the presence of intraerythrocyte bacteria identified as Bartonella bacilliformis, and subsequently, the child was diagnosed with Carrion’s disease. The diagnosis was confirmed by specific polymerase chain reaction. The child was born in a non-endemic B. bacilliformis area and had not traveled to such an area before hospitalization. However, the mother was from an endemic B. bacilliformis area, and posterior physical examination showed the presence of a wart compatible with B. bacilliformis in semi-immune subjects.These data support vertical transmission of B. bacilliformis.
  • Publicación
    Characterization of Plukenetia volubilis L. fatty acid-based alkyd resins
    (Elsevier BV, 2020)
    Hadzich, Antonella
    ;
    Gross, G. Alexander
    ;
    Leimbach, Martin
    ;
    Ispas, Adriana
    ;
    Bund, Andreas
    ;
    Flores, Santiago
    Fatty acid-based alkyd resins prepared with different amounts of glycerol and pentaerythritol were characterized. Sacha inchi oil and linseed oil (comparative purposes) were used as fatty acids' sources. FT-IR and H-1 NMR spectroscopy were done for alkyd structural verification. Alkyd resins were evaluated through physico-chemical (colour, density, viscosity) and thermal characterization. Film coating performance (drying, hardness, chemical resistance) was also studied. The oxidative crosslinking time tendency was corroborated by the quartz crystal microbalance (QCM) technique. Alkyd resins obtained with fatty acids from sacha inchi and linseed oils had similar properties. Results indicated that lighter resins can be obtained from sacha inchi oil, whereas pentaerythritol increases viscosity and thermal stability, and retards drying time of fatty-acid based alkyd resins.
  • Publicación
    Characterization of two Achromobacter xylosoxidans isolates from patients with pertussis-like symptoms
    (Elsevier B.V., 2015)
    Orellana-Peralta, F
    ;
    Jacinto, M
    ;
    Pons, MJ
    ;
    Gomes, C
    ;
    Bada, C
    ;
    Reyes, I
    ;
    Mendoza, JD
    ;
    Ruiz, J
    To characterize two Achromobacter xylosoxidans recovered from 2 patients diagnosed with pertussis during a Bordetella pertussis surveillance program.
  • Publicación
    Chitosan films containing TiO2 nanoparticles modified with tungstophosphoric acid for the photobleaching of malachite green in solid-gas interfaces upon different wavelengths
    (Elsevier, 2018)
    Rengifo-Herrera J.A.
    ;
    Marín-Silva D.A.
    ;
    Mendoza-Portillo E.
    ;
    Pinotti A.N.
    ;
    Pizzio L.R.
    Chitosan (CS) films containing visible light absorbing TiO2 nanoparticles modified with tungstophosphoric acid (TPA-TiO2) at different TPA-TiO2:CS ratios (10%, 20%, 30% and 40% (w/w) called CS/TPA-TiO2-10, CS/TPA-TiO2-20, CS/TPA-TiO2-30, and CS/TPA-TiO2-40 respectively) were prepared. Films were characterized by DRS, SEM-EDS, XRD, ATR-FT-IR, and contact angle (CA). Materials were evaluated in malachite green (MG) photobleaching solid-gas interface reactions upon different wavelengths.
  • Publicación
    Combinatorial approach toward optimization of the light emission intensity of AlOxNy:Yb3+ thin films
    (Optica Publishing Group, 2019)
    Tucto, KY
    ;
    Aponte, W
    ;
    Dulanto, JA
    ;
    Tofflinger, JA
    ;
    Guerra, JA
    ;
    Grieseler, R
    To obtain an adequate luminescent emission, a significant effort must be made to find a suitable host material. An interesting and highly efficient method is a combinatorial approach, which allows high velocity screening of a wider range of properties. In the present work, a compositional gradient-based, thin-film library of 𝑎-AlOxNy:Yb3+ has been prepared by radio frequency co-sputtering from two targets. The ytterbium concentration range spreads from 0.9 to 4.2 at. % and the oxygen to nitrogen ratio from 0.6 to 3.6. Using different annealing temperatures, the activation energy of the rare earth ions and activation mechanisms can be evaluated. Finally, optimal elemental compositions in the investigated range are proposed.
  • Publicación
    Comparison of Methodologies: Analytical Hierarchy Process and Grey Clustering with Entropy Weight for the Multicriteria Assessment of the Energy Sources of Perú
    (Institute of Electrical and Electronics Engineers Inc., 2018)
    Sacasqui M.
    This article introduces a comparison among decision making methodologies applied to energetic policies. Every country has a challenge that is choice the most suitable energetic source in order to the common welfare, it is the reason for use decision making supported by structured methods that can be Analytical Hierarchic Process, Grey Clustering with Entropy Weight (both used in this research) or another. The result shows the differences and similarities due each methodology and for the same case analyzed also the Peruvian energetic sources were qualified. According both methodologies, the most important sources are: hydraulic, natural gas and fuel (saving order). The important sources are: or solar, geothermic, biomass, eolic or geothermic, solar, biomass, eolic (respectively for each method). The less important are: or liquid hydrocarbons, carbon, bio-fuels, sea-wave, tidal, uranium or liquid hydrocarbons, carbon, bio-fuels, uranium, tidal, sea-wave (respectively for each method). Finally this research could be used for improve the decision making in energetic policy topics trough the new method Grey Clustering with Entropy Weight.
  • Publicación
    Determination of the complex refractive index and optical bandgap of CH3NH3PbI3 thin films
    (AIP Publishing, 2017)
    Guerra, J. A.
    ;
    Tejada, A.
    ;
    Korte, L.
    ;
    Kegelmann, L.
    ;
    Tofflinger, J. A.
    ;
    Albrecht, S.
    ;
    Rech, B.
    ;
    Weingartner, R.
    We report the complex refractive index of methylammonium lead iodide (CH3NH3PbI3) perovskite thin films obtained by means of variable angle spectroscopic ellipsometry and transmittance/reflectance spectrophotometry in the wavelength range of 190 nm to 2500 nm. The film thickness and roughness layer thickness are determined by minimizing a global unbiased estimator in the region where the spectrophotometry and ellipsometry spectra overlap. We then determine the optical bandgap and Urbach energy from the absorption coefficient, by means of a fundamental absorption model based on band fluctuations in direct semiconductors. This model merges both the Urbach tail and the absorption edge regions in a single equation. In this way, we increase the fitting region and extend the conventional (αℏω)2-plot method to obtain accurate bandgap values. © 2017 Author(s).
  • Publicación
    Development of the phase composition and the properties of Ti2AlC and Ti3AlC2 MAX-phase thin films – A multilayer approach towards high phase purity
    (Elsevier B.V., 2021)
    Torres C.
    ;
    Quispe R.
    ;
    Calderón N.Z.
    ;
    Eggert L.
    ;
    Hopfeld M.
    ;
    Rojas C.
    ;
    Camargo M.K.
    ;
    Bund A.
    ;
    Schaaf P.
    ;
    Grieseler R.
    MAX phase thin films have been synthesized by thermal treatment of a Ti-Al-C multilayer system. The preparation of the multilayer system was carried out via magnetron sputtering. Based on the thickness ratio among the individual nanoscale monolayers (Ti, Al, C), the resulting MAX phase stoichiometry can be controlled. This paper describes the synthesis of both Ti2AlC and Ti3AlC2 MAX phases from the same precursor multilayer system which is composed of a sequence of Ti/Al/C pure elemental single layers with thicknesses of 14, 6, and 3.5 nm, respectively. This sequence is repeated 22 times with a total thickness of around 500 nm. Rapid thermal treatment tests were performed to study the phase development. The Ti2AlC MAX phase forms in a temperature range below 850 °C, whereas the Ti3AlC2 MAX phase starts to form at temperatures above 850 °C and reaches its highest phase purity at 950 °C. The thin film structures were studied by X-ray diffraction and Raman spectroscopy. Furthermore, the electrical and mechanical properties were investigated to gain more insights regarding the phase transformation and their influence on the thin film properties. © 2020 Elsevier B.V.
  • Publicación
    Efecto de la adición de fluido folicular al medio de maduración de ovocitos para la producción In vitro de embriones de bovino (Bos taurus)
    (Universidad Nacional Jorge Basadre Grohmann, 2015)
    Limache Coaquera, Tito
    El presente trabajo de investigación se realizó en la ciudad de Lima, con el objetivo de evaluar el efecto de la adición del fluido folicular (FF) al medio de maduración de ovocitos sobre la producción in vitro de embriones bovinos.
  • Publicación
    Effect of impregnation solutions on the synthesis of Ni-Cu/Al2O3 catalyst to obtain carbon nanofibers
    (IOP Publishing, 2018)
    Almiron, J
    ;
    Alcazar, H
    ;
    Churata, R
    ;
    Roudet, F
    ;
    Ziouche, K
    ;
    Chicot, D
    The present work reports on the influence of nickel molar loading and impregnation solutions, nitrate salts and copper and nickel ammonium complexes, on the synthesis of Ni-Cu catalyst supported on alumina for obtaining carbon nanofibers by catalytic chemical vapor deposition of methane. These catalysts were characterized by N2 adsorption-desorption, x-ray Diffraction, Thermo-Gravimetric Analysis and Scanning Electron Microscopy for the carbon nanostructures analysis.
  • Publicación
    Esterification and Characterization of Starch From Andean Tubers
    (Wiley, 2019)
    Velasquez-Barreto, FF
    ;
    Bello-Perez, LA
    ;
    Yee-Madeira, H
    ;
    Sanchez, CEV
    Starch is isolated from the Andean tubers olluco (Ollucus tuberosus) and oca (Oxalis tuberosa) and modified with octenylsuccinic anhydride (OSA); subsequently, the morphological, molecular, and physicochemical characteristics are evaluated. The isolated starch of olluco and oca results in a powder with a purity of 93.2 and 92.8%, respectively; the amylose content of starch isolated from olluco and oca are 27.1 and 28.2%, respectively.
  • Publicación
    Estudio experimental del acabado antimicrobiano textil con nanopartículas: obtención, aplicación y control
    (Universidad Nacional de Ingeniería, 2014)
    Román Mendoza, Luz Esmeralda
    ;
    Román Mendoza, Luz Esmeralda
    ;
    Román Mendoza, Luz Esmeralda
    La realización de este tema tesis es producto del trabajo de investigación que se llevó a cabo en la Facultad de Ingeniería Química y Textil, la Facultad de Ciencias de la Universidad Nacional de Ingeniería y en el Laboratorio de Investigación y Desarrollo de la Universidad Peruana Cayetano Heredia, bajo la supervisión de: Ing. Carmen Uribe V., Ing. Elsa Roca M., Ing. Marco Brañez S., Dra. Mónica Gómez L., Dr. José Solís V., y la M.Sc. Dora Maurtua. El tema de tesis es la investigación y desarrollo de un producto de acabado textil con propiedades antimicrobianas a base de nanopartículas de ZnO2, para ello se ha hecho diversos análisis como: síntesis, caracterización estructural y morfológica, solideces, pruebas físicas y enfrentamientos microbiológicos.
  • Publicación
    Evaluation of the leishmanicidal activity of plants used by Peruvian Chayahuita ethnic group
    (Elsevier B.V., 2007)
    Estevez Y.
    ;
    Castillo D.
    ;
    Pisango M.T.
    ;
    Arevalo J.
    ;
    Rojas R.
    ;
    Alban J.
    ;
    Deharo E.
    ;
    Bourdy G.
    ;
    Sauvain M.
    Aim of the study: A total of 27 ethanolic plant extracts from 27 species were screened for leishmanicidal activity in vitro against Leishmania amazonensis. Most of the selected species (19) are traditionally used by the Chayahuitas, an Amazonian Peruvian ethnic group, to treat skin affections and/or leishmaniasis.
  • Publicación
    Four new species of Aleiodes (Hymenoptera: Braconidae: Rogadinae) from the Neotropical Region
    (Cambridge University Press (CUP), 2017)
    Garro, Lidia Sulca
    ;
    Shimbori, Eduardo Mitio
    ;
    Penteado-Dias, Angelica Maria
    ;
    Shaw, Scott Richard
    Four new species of the Aleiodes apicalis (Brulle) species group (Hymenoptera: Braconidae: Rogadinae) from the Neotropical Region are described and illustrated: Aleiodes ambrosiae new species. from Peru, A. aquilesi new species from Costa Rica, and A. sachambrosiae new species and A. tapirape new species from Brazil. We also add new distribution records for Aleiodes molestus Cresson, from Costa Rica. With the addition of the new species, the A. apicalis species group has 11 species from the New World, six of which are recorded from Neotropical Region.
  • Publicación
    Función de transferencia de movimiento del suelo entre dos estaciones sísmicas cercanas: efecto de sitio
    (Universidad Nacional Mayor de San Marcos, 2016)
    Flores Cuba, Joseph Michael
    Las condiciones de sitio, las características geológicas y geométricas de los depósitos de suelo y la topografía superficial, influencian fuertemente en la amplitud, contenido de frecuencias y duración de las ondas sísmicas incidentes en un sitio. Esta influencia ha sido observada mediante la comparación de registros sísmicos obtenidos de sitios con diferentes condiciones geológicas locales. Este fenómeno es conocido como efecto de sitio. Revisa los estudios más relevantes acerca del efecto de sitio con el objetivo de analizar y comprender la influencia de las condiciones locales en la transferencia de movimiento de las ondas incidentes en un sitio.
  • Publicación
    Genome sequence and analysis of the tuber crop potato
    (Springer Nature Limited, 2011)
    Xu X.
    ;
    Pan S.
    ;
    Cheng S.
    ;
    Zhang B.
    ;
    Mu D.
    ;
    Ni P.
    ;
    Zhang G.
    ;
    Yang S.
    ;
    Li R.
    ;
    Wang J.
    ;
    Orjeda G.
    ;
    Guzman F.
    ;
    Torres M.
    ;
    Lozano R.
    ;
    Ponce O.
    ;
    Martinez D.
    ;
    De La Cruz G.
    ;
    Chakrabarti S.K.
    ;
    Patil V.U.
    ;
    Skryabin G.
    ;
    Kuznetsov B.B.
    ;
    Ravin N.V.
    ;
    Kolganova T.V.
    ;
    Beletsky A.V.
    ;
    Mardanov A.V.
    ;
    Di Genova A.
    ;
    Bolser D.M.
    ;
    Martin D.M.A.
    ;
    Li G.
    ;
    Yang Y.
    ;
    Kuang H.
    ;
    Hu Q.
    ;
    Xiong X.
    ;
    Bishop G.J.
    ;
    Sagredo B.
    ;
    Mejía N.
    ;
    Zagorski W.
    ;
    Gromadka R.
    ;
    Gawor J.
    ;
    Szczesny P.
    ;
    Huang S.
    ;
    Zhang Z.
    ;
    Liang C.
    ;
    He J.
    ;
    Li Y.
    ;
    He Y.
    ;
    Xu J.
    ;
    Zhang Y.
    ;
    Xie B.
    ;
    Du Y.
    ;
    Qu D.
    ;
    Bonierbale M.
    ;
    Ghislain M.
    ;
    Herrera M.D.R.
    ;
    Giuliano G.
    ;
    Pietrella M.
    ;
    Perrotta G.
    ;
    Facella P.
    ;
    O'Brien K.
    ;
    Feingold S.E.
    ;
    Barreiro L.E.
    ;
    Massa G.A.
    ;
    Diambra L.
    ;
    Whitty B.R.
    ;
    Vaillancourt B.
    ;
    Lin H.
    ;
    Massa A.N.
    ;
    Geoffroy M.
    ;
    Lundback S.
    ;
    DellaPenna D.
    ;
    Buell C.R.
    ;
    Sharma S.K.
    ;
    Marshall D.F.
    ;
    Waugh R.
    ;
    Bryan G.J.
    ;
    Destefanis M.
    ;
    Nagy I.
    ;
    Milbourne D.
    ;
    Thomson S.J.
    ;
    Fiers M.
    ;
    Jacobs J.M.E.
    ;
    Nielsen K.L.
    ;
    Sønderkær M.
    ;
    Iovene M.
    ;
    Torres G.A.
    ;
    Jiang J.
    ;
    Veilleux R.E.
    ;
    Bachem C.W.B.
    ;
    De Boer J.
    ;
    Borm T.
    ;
    Kloosterman B.
    ;
    Van Eck H.
    ;
    Datema E.
    ;
    Hekkert B.L.
    ;
    Goverse A.
    ;
    Van Ham R.C.H.J.
    ;
    Visser R.G.F.
    Potato (Solanum tuberosum L.) is the world’s most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin.