Luis Lisandro López Taborda, Heriberto Maury, Jovanny Pacheco,
Purpose There are many investigations in design methodologies, but there are also divergences and convergences as there are so many points of view. This study aims to evaluate to corroborate and deepen other researchers’ findings, dissipate divergences and provide directing to future work on the subject from a methodological and convergent perspective. Design/methodology/approach This study analyzes the previous reviews (about 15 reviews) and based on the consensus and the classifications provided ...
Tópico(s): Innovations in Concrete and Construction Materials
2021 - Emerald Publishing Limited | Rapid Prototyping Journal
R. Ramirez, Enrique Delgado Ávila, Luis Lisandro López Taborda, Antonio Bula, Jorge Duarte Forero,
A model has been developed to characterize the cavitation phenomenon in dredging centrifugal pumps. The operating parameters of a cutter type dredger: swing speed, dredging depth, and inclination, impeller rpm, as well as slurry characterizations such as density and velocity, are introduced, to determine how they influence the operation of the dredge pump. The geometric characterization of the hydraulic transport system of the dredger was performed. With the dredge operationaĺs parameters, along ...
Tópico(s): Cyclone Separators and Fluid Dynamics
2020 - Elsevier BV | Alexandria Engineering Journal
Jorge Duarte Forero, Luis Lisandro López Taborda, Antonio Bula,
In the dredging industry, centrifugal pumps are the cornerstone of performance and productivityin operation. However, these characteristics are affected because the dredge operators are unaware of the response of the pump efficiency under operating conditions, as well as the fuel consumed by the engine that drives it. Experimental tests are discarded as a solution to this situation, due to its high cost and time requirements, presenting an opportunity for numerical analysis through computational ...
Tópico(s): Cyclone Separators and Fluid Dynamics
2019 - | International Review of Mechanical Engineering (IREME)
Lisandro López, Mario Silveira, Charles R. Stern,
Se presentan los resultados de análisis geoquímicos realizados a artefactos de obsidiana procedentes de los sitios arqueológicos Alero Los Cipreses y Alero
Tópico(s): Indigenous Cultures and History
2010 - University of Magallanes | Magallania
Erwin Molino Alvarez, Sergio Andres Quintana González, Luis Lisandro López Taborda, Enrique Esteban Niebles Núñez,
Purpose Additive manufacturing has disadvantages, such as the maximum part size being limited by the machine’s working volume. Therefore, if a part more considerable than the working volume is required, the part is produced in parts and joined together. Among the many methods of joining thermoplastic parts, adhesives and mechanical interlocking are considered. This study aims to characterize and optimize mechanically stressed adhesive joints combined with female and male mechanical interlocking ...
Tópico(s): Design Education and Practice
2023 - Emerald Publishing Limited | Rapid Prototyping Journal
Patricia López‐Caballero, J. Lopez, Lisandro J. Giovanetti, David Buceta, S. Miret‐Artés, M. Arturo López‐Quintela, Félix G. Requejo, María Pilar de Lara‐Castells,
Ag 5 -induced formation of surface polarons at the Ag 5 –TiO 2 interface enables to reveal a general polarization phenomenon.
Tópico(s): Catalytic Processes in Materials Science
2020 - Royal Society of Chemistry | Journal of Materials Chemistry A
María Pilar de Lara‐Castells, Andreas Hauser, J. Lopez, David Buceta, Lisandro J. Giovanetti, M. Arturo López‐Quintela, Félix G. Requejo,
The photoabsorption of TiO 2 in the UV gets enhanced and extended to the visible region by decoration with highly stable Cu 5 clusters.
Tópico(s): ZnO doping and properties
2019 - Royal Society of Chemistry | Journal of Materials Chemistry A
Pablo A. Kler, Ezequiel J. López, Lisandro Dalcín, Fabio A. Guarnieri, Mario A. Storti,
This article discusses high performance numerical simulations of electrokinetic flow and transport phenomena in microfluidic chips. Modeling grounds on conservation equations of mass, momentum and electric charge in the framework of continuum mechanics. Two examples of interest in microfluidics are considered as study cases. Three dimension effects and whole chip geometries are taking into account. All numerical simulations presented are performed with PETSc-FEM within a Python programming environment ...
Tópico(s): Electrowetting and Microfluidic Technologies
2009 - Elsevier BV | Computer Methods in Applied Mechanics and Engineering
Fabián Videla, G. A. Torchia, Daniel C. Schinca, Lucía B. Scaffardi, Pablo Moreno, C. Méndez, Lisandro J. Giovanetti, J. Lopez, L. Roso,
Studies of fragmentation process of gold nanoparticles (Nps) in deionized water after generation by femtosecond laser ablation were performed. To analyze the fragmentation process, direct IR ultrafast pulses or super-continuum (SC) radiation focused in the colloidal solution were used in separate steps. IR pulses and SC generated externally in a sapphire crystal or directly inside the water were applied under low fluence regime. In the latter cases, to evaluate the effect on fragmentation of the different ...
Tópico(s): Laser-induced spectroscopy and plasma
2010 - American Institute of Physics | Journal of Applied Physics
Gastón Corthey, Lisandro J. Giovanetti, J. Lopez, Eugenia Zelaya, Aldo A. Rubert, Guillermo Benítez, Félix G. Requejo, Mariano H. Fonticelli, R. C. Salvarezza,
In this paper, the synthesis of gold@gold(I)−thiolate core@shell nanoparticles is described for the first time. The chemical nature and structure of these nanoparticles were characterized by a multi-technique approach. The prepared particles consist of gold metallic cores, about 1 nm in size, surrounded by stable gold(I)−thiomalate shells (Au@Au(I)−TM). These nanoparticles could be useful in medicine due to the interesting properties that gold(I)−thiomalate has against rheumatoid arthritis. Furthermore, ...
Tópico(s): Nanomaterials for catalytic reactions
2010 - American Chemical Society | ACS Nano
Produção Nacional
Revisado por pares
Doris Grumelli, Carolina Vericat, Guillermo Benítez, M. E. Vela, R. C. Salvarezza, Lisandro J. Giovanetti, J. Lopez, Félix G. Requejo, A. F. Craievich, Young‐Seok Shon,
Gold nanoparticle-(AuNP)-modified carbon graphite surfaces have been prepared by simple immersion of highly oriented pyrolytic graphite (HOPG) in hexane solutions containing 3 nm diameter butanethiol- or nonanethiol-capped nanoparticles. The AuNP adsorb on the HOPG surface free of unbounded thiols, remaining unchanged with time. The amount of adsorbed thiol-protected AuNP depends on concentration and time. The reductive desorption of thiols from the AuNP produces an efficient release of more than ...
Tópico(s): Molecular Junctions and Nanostructures
2007 - American Chemical Society | The Journal of Physical Chemistry C
Alejandro González Orive, Doris Grumelli, Carolina Vericat, J. Lopez, Lisandro J. Giovanetti, Guillermo Benítez, Julio C. Azcárate, Gastón Corthey, Mariano H. Fonticelli, Félix G. Requejo, Alberto Hernández Creus, R. C. Salvarezza,
Reductive electrodesorption has been used to produce "naked" gold nanoparticles (AuNPs) 3 nm in size on HOPG from different thiolate-capped AuNPs. The clean AuNPs transform the electrocatalytic inert HOPG into an active surface for hydrogen peroxide electroreduction, causing a lowering of the cathodic overpotential of 0.25 V with respect to the Au(111) surface. Compared to the plain gold substrates, the nanostructures promote only a slight increase in the hydrogen evolution reaction. In a second modification ...
Tópico(s): Nanomaterials for catalytic reactions
2011 - Royal Society of Chemistry | Nanoscale
Produção Nacional
Revisado por pares
Lisandro J. Giovanetti, J. Lopez, Michael Foxe, Louis C. Jones, Matthias M. Koebel, Gábor A. Somorjai, A. F. Craievich, Miquel Salmerón, Félix G. Requejo,
Abstract Polyvinylpyrollidone (PVP)‐capped platinum nanoparticles (NPs) are found to change shape from spherical to flat when deposited on mesoporous silica substrates (SBA‐15). Transmission electron microscopy (TEM), small‐angle X‐ray scattering (SAXS), and extended X‐ray absorption fine structure (EXAFS) analyses are used in these studies. The SAXS results indicate that, after deposition, the 2 nm NPs have an average gyration radius 22% larger than in solution, while the EXAFS measurements indicate ...
Tópico(s): Electrocatalysts for Energy Conversion
2011 - Wiley | Small
J. Lopez, Lisandro J. Giovanetti, Félix G. Requejo, Steven R. Isaacs, Young‐Seok Shon, Miquel Salmerón,
The bonding of hexanethiols to gold nanoparticles of 1.5, 2.0, and $3\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ was studied using x-ray absorption near-edge spectroscopy (XANES) and extended x-ray absorption fine structure (EXAFS). The XANES spectra revealed that a substantial fraction of weakly bound hexanethiol molecules are present in addition to those forming covalent bonds with Au atoms. The weakly bound molecules can be removed by washing in dichloromethane. After removal of the weakly bound molecules ...
Tópico(s): Quantum Dots Synthesis And Properties
2006 - American Physical Society | Physical Review B
Produção Nacional
Revisado por pares
J. Lopez, Lisandro J. Giovanetti, A. F. Craievich, Flávio C. Vicentin, M. Marín-Almazo, Miguel José‐Yacamán, Félix G. Requejo,
We report a structural characterization of palladium nanoparticles, with an average diameter of 1.2 nm, capped with three different n-alkyl thiol molecules (n=12, 16 and 18). For this purpose several experimental techniques were used, namely X-ray absorption fine structure (XAFS), small angle X-ray scattering (SAXS) and high-resolution electron transmission microscopy (HRTEM). SAXS and HRTEM results yielded the sizes of the Pd nanoparticles in each sample. The effects of sulfur–palladium interaction ...
Tópico(s): Molecular Junctions and Nanostructures
2006 - Elsevier BV | Physica B Condensed Matter
Gastón Corthey, Aldo A. Rubert, A. Lorena Picone, Gilberto Casillas, Lisandro J. Giovanetti, J. Lopez, Eugenia Zelaya, Guillermo Benítez, Félix G. Requejo, Miguel José‐Yacamán, R. C. Salvarezza, Mariano H. Fonticelli,
This paper establishes the chemical nature of Pd nanoparticles protected by alkanethiolates that were prepared through a ligand place-exchange approach and the two-phase method, first developed for Au nanoparticles by Brust and Schiffrin. After 10 years since the first study on this kind of Pd nanoparticles was published, the surface composition of the particles is a matter of debate in the literature and it has not been unambiguously assessed. The nanoparticles were studied by means of several ...
Tópico(s): Nanomaterials for catalytic reactions
2012 - American Chemical Society | The Journal of Physical Chemistry C
Domingo I. García-Gutiérrez, Claudia Gutiérrez-Wing, Lisandro J. Giovanetti, J. Lopez, Félix G. Requejo, Miguel José‐Yacamán,
Pt-Au bimetallic nanoparticles have been synthesized by the polyol method and stabilized with poly(vinylpyrrolidone) (PVP), modifying the temperature of synthesis. Interesting structure changes were observed in the nanoparticles as the temperature was varied. At lower temperatures no bimetallic nanoparticles were detected, but as the temperature increased bimetallic nanoparticles started to appear, commonly obtaining core-shell nanoparticles, always covered by the polymer. This originates the modification ...
Tópico(s): nanoparticles nucleation surface interactions
2005 - American Chemical Society | The Journal of Physical Chemistry B
Produção Nacional
Revisado por pares
Paula S. Cappellari, David Buceta, Gustavo M. Morales, César A. Barbero, M. Sergio Moreno, Lisandro J. Giovanetti, J. Lopez, Félix G. Requejo, A. F. Craievich, Gabriel A. Planes,
We report a synthetic approach for the production of ultra-small (0.6 nm) gold nanoparticles soluble in water with a precise control of the nanoparticle size. Our synthetic approach utilizes a pH-depending Au–cysteine polymer as a quencher for the AuNPs grown. The method extends the synthetic capabilities of nanoparticles with sizes down to 1 nm. In addition to the strict pH control, the existence of free –SH groups present in the mixture of reaction has been observed as a key requirement for the ...
Tópico(s): Quantum Dots Synthesis And Properties
2014 - Elsevier BV | Journal of Colloid and Interface Science
Trenton Otto, J. Lopez, Lisandro J. Giovanetti, Félix G. Requejo, Stacey I. Zones, Enrique Iglesia,
AuPd, AuPt, and PdPt bimetallic clusters uniform in size and composition were prepared using hydrothermal assembly of LTA crystals around cationic precursors stabilized by protecting mercaptosilane ligands. The sulfur moiety in these bifunctional ligands forms adducts that prevent premature reduction or precipitation of metal precursors during crystallization. The silane groups can form bridges with silicate oligomers as they form, thus enforcing homogeneous distributions of precursors throughout ...
Tópico(s): Electrocatalysts for Energy Conversion
2016 - Elsevier BV | Journal of Catalysis
Jasmine Martinez, Jennifer S. Fernandez, Christine Liu, Amparo Hoard, Anthony M. Mendoza, Jun Nakanouchi, Nyah Rodman, Robert Courville, Marisel R. Tuttobene, Carolina López, Lisandro J. González, Parvin Shahrestani, Krisztina M. Papp‐Wallace, Alejandro J. Vila, Marcelo E. Tolmasky, Robert A. Bonomo, Rodrigo Sieira, María Soledad Ramirez,
Acinetobacter baumannii is a feared, drug-resistant pathogen, characterized by its ability to resist extreme environmental and nutrient-deprived conditions. Previously, we showed that human serum albumin (HSA) can increase foreign DNA acquisition specifically and alter the expression of genes associated with pathogenicity. Moreover, in a recent genome-wide transcriptomic study, we observed that pleural fluid (PF), an HSA-containing fluid, increases DNA acquisition, can modulate cytotoxicity, and control ...
Tópico(s): Escherichia coli research studies
2019 - Nature Portfolio | Scientific Reports
Fanny Huang, Noelle Fitchett, Chelsea Razo-Gutierrez, Casin Le, Jasmine Martinez, Grace Ra, Carolina López, Lisandro J. González, Rodrigo Sieira, Alejandro J. Vila, Robert A. Bonomo, María Soledad Ramirez,
Carbapenem-resistant A. baumannii (CRAB) is recognized as one of the most threatening Gram-negative bacilli. H-NS is known to play a role in controlling the transcription of a variety of different genes, including those associated with the stress response, persistence, and virulence. In the present work, we uncovered a link between the role of H-NS in the A. baumannii stress response and its relationship with the envelope stress response and resistance to DNA-damaging agents. Overall, we posit a ...
Tópico(s): Escherichia coli research studies
2020 - American Society for Microbiology | mSphere
Mark D. Adams, Fernando Pasterán, Germán M. Traglia, Jasmine Martinez, Fanny Huang, Christine Liu, Jennifer S. Fernandez, Carolina López, Lisandro J. González, Ezequiel Albornoz, Alejandra Corso, Alejandro J. Vila, Robert A. Bonomo, María Soledad Ramirez,
A 4-year surveillance of carbapenem-resistant Acinetobacter spp. isolates in Argentina identified 40 strains carrying blaNDM-1 Genome sequencing revealed that most were Acinetobacter baumannii, whereas seven represented other Acinetobacter spp. The A. baumannii genomes were closely related, suggesting recent spread. blaNDM-1 was located in the chromosome of A. baumannii strains and on a plasmid in non-A. baumannii strains. A resistance gene island carrying blaPER-7 and other resistance determinants ...
Tópico(s): Vibrio bacteria research studies
2020 - American Society for Microbiology | Antimicrobial Agents and Chemotherapy
Patricia de la Presa, T. Rueda, A. Hernando, J. Lopez, Lisandro J. Giovanetti, Félix G. Requejo,
In this work we present new results on spontaneous oxidation of disordered fcc FePt nanoparticles. The “as-made” oleic acid and oleylamine coated FePt nanoparticles of average size 4 nm synthesized by a high-boiling coordinating solvent method were exposed to air over a period of days and characterized structurally and magnetically by means of different techniques such as XANES, XPS, EXAFS, and SQUID magnetometry. The “as-made” FePt nanoparticles stabilize in the disordered fcc structure and have ...
Tópico(s): Magnetic Properties and Synthesis of Ferrites
2008 - American Institute of Physics | Journal of Applied Physics
Richard Hoyos–López, Lisandro Pacheco-Lugo, Luz Adriana Agudelo, Germán Zafra, Pedro Blanco, Omar Triana‐Chávez,
Introduction. Chagas disease is a major public health problem in Latin America. In Colombia, a large area has the ecoepidemiological conditions which favor the active transmition of this infection.Objective. This study was undertaken in a population from the municipality of Morroa, Sucre Province, to evaluate risk factors and to determine the seroprevalence to Chagas disease. Materials and methods. A questionnaire was given to a sample population of 122 people classed as rural (n=76) or urban area ( ...
Tópico(s): Educational Methods and Psychological Studies
2007 - National Institute of Health | Biomédica
Yasser A. Attia, David Buceta, Félix G. Requejo, Lisandro J. Giovanetti, M. Arturo López‐Quintela,
Involvement of semiconductor-like Ag clusters in the photodissolution of gold nanorods and nanoprisms by low-power UV irradiation.
Tópico(s): nanoparticles nucleation surface interactions
2015 - Royal Society of Chemistry | Nanoscale
María C. Dalfovo, Lisandro J. Giovanetti, J. Lopez, R. C. Salvarezza, Félix G. Requejo, Francisco J. Ibáñez,
We explore into the role of the organic ligands composition surrounding Au nanoparticles (NPs) toward internanoparticles distance changes and film structure during vapor sensing by the use of in situ grazing-incidence small-angle X-ray scattering (GISAXS) and other relevant techniques. We observed distinct changes in core-to-core distance and film structure upon measured concentrations of polar ethanol (EtOH) and nonpolar toluene (Tol) vapors. As-formed tetraoctylammonium bromide (TOABr)-coated Au NPs ( ...
Tópico(s): Molecular Junctions and Nanostructures
2015 - American Chemical Society | The Journal of Physical Chemistry C
Mario Silveira, Lisandro López, Guido Pastorino,
Se determina la procedencia de fragmentos de moluscos marinos hallados en los aleros Los Cipreses y Lari-viere, en el area del lago Traful, sur de la provincia de Neuquen. Estudios previos en areas cercanas con mayor proximidad a la costa del oceano Pacifico suponen que las piezas recuperadas evidencian contacto con grupos provenientes del lado occidental de la cordillera de Los Andes –Chile. En este trabajo se indica que parte de las valvas estudiadas corresponden a fosiles marinos o fluviales no ...
Tópico(s): Isotope Analysis in Ecology
2010 - National University of Central Buenos Aires | Intersecciones en antropología
Luis Lisandro López Taborda, Eduar Pérez, Daniel Eduardo Clavijo Quintero, José Fernando Noguera Polania, Habib R. Zambrano, Heriberto Maury, Iván Esparragoza,
Purpose This study aims to evaluate the impact breaking energy of the parts manufactured by the fused filament fabrication (FFF) method. The evaluation considers the use of the epoxy resin coating, different materials and different printing orientations. Design/methodology/approach The authors developed an experimental statistical design using 54 experimental trials. The experiments’ output variable is the impact break energy of the parts manufactured by the FFF method. The input variables for the ...
Tópico(s): Manufacturing Process and Optimization
2021 - Emerald Publishing Limited | Rapid Prototyping Journal
Lisandro Alberto Encalada Mena, Ma. Eugenia López Arellano, Pedro Mendoza de Gives, Enrique Liébano Hernández, Víctor Vázquez Prats, Gerardo Vera Ycuspinera,
Resumen es: El objetivo del presente trabajo fue detectar resistencia a ivermectina en nematodos gastrointestinales en bovinos jovenes infectados naturalmente en Cam...
Tópico(s): Rabbits: Nutrition, Reproduction, Health
2008 - National Autonomous University of Mexico | Veterinaria
Produção Nacional
Revisado por pares
Lisandro J. Giovanetti, J. Lopez, Félix G. Requejo, Domingo I. García-Gutiérrez, Miguel José‐Yacamán, A. F. Craievich,
The Debye temperature of Pt nanoparticles (NP) capped in PVP-K30 with an average diameter of 3 nm was determined from extended X-ray absorption fine structure measurements between 20 and 373 K. The size distribution of the NP was determined by high-resolution transmission electron microscopy, high-angle annular dark field, and small-angle X-ray scattering. We have experimentally established that the Debye temperature of truncated cuboctahedron, capped Pt NP is 70 K higher than that of bulk Pt metal. ...
Tópico(s): Chemical and Physical Properties of Materials
2007 - American Chemical Society | The Journal of Physical Chemistry C