Modelos de optimización en la gestión de proyectos. Caso práctico aplicado a una empresa de servicios

En el trabajo se diseña un modelo de planificación de proyectos junto a la empresa EFOR. Para ello se realiza una revisión bibliográfica de los distintos modelos de optimización matemática desarrollados hasta el momento ligados con la Planificación de Proyectos, dando un especial enfoque a los que implementan restricciones en los recursos. Para la resolución del modelo se ha utilizado Python como lenguaje de programación, el cual incluye una librería de Programación Lineal Mixta, MILP, que utiliza CBC como solucionador. Además se realiza un análisis de los datos proporcionados por la empresa con los que se generan nuevas restricciones disminuyendo el tiempo de ejecución del modelo propuesto.<br /

Aspect-ratio and lateral-resolution enhancement in force microscopy by attaching nanoclusters generated by an ion cluster source at the end of a silicon tip

One of the factors that limit the spatial resolution in atomic force microscopy (AFM) is the physical size of the probe. This limitation is particularly severe when the imaged structures are comparable in size to the tip’s apex. The resolution in the AFM is usually enhanced by using sharp tips with high aspect ratios. In the present paper we propose an approach to modify AFM tips that consists of depositing nanoclusters on standard silicon tips. We show that the use of those tips leads to atomic force microscopy images of higher aspect ratios and spatial resolution. The present approach has two major properties. It provides higher aspect-ratio images of nanoscale objects and, at the same time, enables to functionalize the AFM tips by depositing nanoparticles with well-controlled chemical composition.The authors acknowledge the Spanish Ministerio de Ciencia e Innovación and Comisión Interministerial para la Ciencia Y la Tecnología—CICYT under Contract Nos. MAT2008-06765-C02-02, MAT2009-08650, and CSD2007 00041 (Nanoselect) and through the FPI and “Juan de La Cierva” programs for financial support.Peer reviewe

Modification of AFM tips by depositing nanoparticles with an Ion Cluster Source. Enhancement of the aspect-ratio and lateral resolution

Póster presentado en la NanoSpain Conference (Nanoiberian Conference), celebrada en Bilbao del 11 al 14 de abril de 2011.One of the factors that limit the spatial resolution in atomic force microscopy (AFM) is the physical size of the probe. This limitation is particularly severe when the imaged structures are comparable in size to the tip¿s apex. The resolution in the AFM is usually enhanced by using sharp tips with high aspect ratios. In the present paper we propose an approach to modify AFM tips that consists of depositing nanoclusters on standard silicon tips. We show that the use of those tips leads to atomic force microscopy images of higher aspect ratios and spatial resolution. The present approach has two major properties. It provides higher aspect-ratio images of nanoscale objects and, at the same time, enables to functionalize the AFM tips by depositing nanoparticles with well-controlled chemical composition.Peer Reviewe

Application of diamond-like carbon coatings to elastomers frictional surfaces

Nitrile-butyl rubber-like materials were coated with amorphous hydrogenated diamond-like carbon (DLC) coatings in order to modify their surface and tribological properties. Measurements of water contact angle were performed by the sessile drop method and showed that the coated samples are more hydrophobic with water contact angles up to 116°. The surface free energy of the elastomers was calculated by the acid-base regression method considering polar and dispersive contributions and the results were correlated with changes in the surface chemistry measured by X-ray photoelectron spectroscopy. It has been found that the lower presence of oxygen functional groups on the elastomer surfaces led to lower surface free energies, even though the polar contribution was not predominant. We also found that the DLC coatings led to a significant decrease of the surface free energy (up to 16%) and that there is a good correlation between the surface free energy values and the corresponding water contact angle values. The coefficient of friction was also measured and presented a significant decrease after coating with DLC. © 2008 Elsevier Ltd. All rights reserved.The authors acknowledge the financial support of the EU from the Sixth framework programme in the KRISTAL Project no. 515837-2. L. Martínez and Y. Huttel acknowledge the Spanish “Ministerio de Educación y Ciencia” for the “Juan de la Cierva” and “Ramón y Cajal” programmes, respectively. R. Nevshupa acknowledges the “Marie Curie” programme (MIF1-CT-2006-22067)

Experimental Station for Generation, Processing and Diagnostics of Nanoparticles of Astrophysical Interest

Europhysics Sectional Conference on the Atomic and Molecular Physics of Ionized Gases. ESCAMPIG XXIV.Glasgow July 17-21 (2018). .--file:///C:/Users/BIBLIO~1/AppData/Local/Temp/CONGRESOS_Y_CONFERENCIAS752874-1.pd

Applications in energy and environment of nanocolumnar films

Resumen del trabajo presentado en el CMD30-FisMat 2023 celebrado en Milán (Italia), del 4 al 8 de septiembre de 2023Glancing Angle Deposition (GLAD) with magnetron sputtering (MS) is an easy and versatile route to fabricate nanocolumnar films in large areas (several cm2 and above) in a single-step process, in clear contrast to other techniques in the nanoscale range such as e-beam lithography and ion-beam lithography. The morphology of the nanocolumns can be controlled depending on several parameters such as the gas pressure, the angle of inclination of the substrate and its possible rotation, the electromagnetic power, the deposition time, and the optional use of collimating masks [1-4]. Moreover, as GLAD with MS it is usually carried out at RT and does not involve chemical products (thus, without associated recycling issues), this technique is environmentally friendly. In this talk, I will start explaining the fundamentals of GLAD with MS and then I will present some recent examples of nanocolumnar films that are of interest in the field of energy and environment: Gold nanocolumnar templates for effective chemical sensing by surface-enhanced Raman scattering [5], Iron nanocolumnar films with tailored magnetic behavior [6], and Titanium oxide nanocolumnar films that exhibit photo‐induced self‐cleaning properties [7]. It will be finally shown that this latter effect can be enhanced when the nanocolumns are decorated with gold nanoparticles using a gas aggregation source that is also based on MS. References:[1] R. Alvarez et al., Nanotechnology 24, 045604 (2013). [2] R. Alvarez et al., J. Phys. D: Appl. Phys. 49, 045303 (2016). [3] A. Vitrey et al., Beilstein J. Nanotechnol. 8, 434 (2017).[4] G. Troncoso et al., Appl. Surf. Sci. 526, 146699 (2020).[5] G. Barbillon et al., Nanomaterials 12, 4157 (2022).[6] E. Navarro et al., Nanomaterials 12, 1186 (2022).[7] F. Fresno et al., Adv. Sustainable Syst. 5, 2100071 (2021)

Nanomaterials to aid wound healing and infection control

The management and treatment of infectious bacterial diseases in wound healing have both become significant research areas in the biomedical field. While current treatments show limitations related to toxicity and exposure time, nanotechnology has become a potential alternative to overcome such challenges. The application of different nanomaterials, with a wide range of elemental compositions, morphologies, and features, has become an essential tool in managing wound healing infections. This book chapter shows an updated view of the newest trends in the control and treatment of bacterial proliferation in the wound bed by utilizing various metal- and nonmetal-based nanostructures

Photoinduced Charge Transfer and Trapping on Single Gold Metal Nanoparticles on TiO2

We present a study of the effect of gold nanoparticles (Au NPs) on TiO2 on charge generation and trapping during illumination with photons of energy larger than the substrate band gap. We used a novel characterization technique, photoassisted Kelvin probe force microscopy, to study the process at the single Au NP level. We found that the photoinduced electron transfer from TiO2 to the Au NP increases logarithmically with light intensity due to the combined contribution of electron-hole pair generation in the space charge region in the TiO2-air interface and in the metal-semiconductor junction. Our measurements on single particles provide direct evidence for electron trapping that hinders electron-hole recombination, a key factor in the enhancement of photo(electro)catalytic activity.This work was supported by the Office of Basic Energy Sciences (BES) of the U.S. Department of Energy (DOE) under contract DE-AC02-05CH11231 through the Structure and Dynamics of Materials Interfaces Program (FWP KC31SM) and the Molecular Foundry. M.L. acknowledges funds from Comunidad de Madrid (P2018/EMT-4308), a Fulbright grant PRX16/00564, and the MCIU-AEI-FEDERUE (RTI2018-096937-B-C22 and MAT2014-59772-C2-1-P). J.C. acknowledges financial support from Ministerio de Ciencia e Innovación (MICINN) and the European Union through the project PID2019-104272RB-C52. Also, Y.H. acknowledges financial support from MCIU through MAT2014-59772-C2-2- P and L.M. from EC through ERC-2013-SYG-610256. V.A.P.O. and M.B. acknowledge the financial support from EC through ERC CoG HyMAP 648319, MINECO PID2019- 106315RB-I00 and ENE2017-89170-R, ″Comunidad de Madrid″ and European Structural Funds (FotoArt-CM project S2018/NMT-4367) and Fundación Ramón Areces (Art-Leaf project). M.B. also thanks the Juan de la Cierva Incorporación contract (IJC2019042430-I). X.Z. was supported by the NSF-BSF 359 grant number 1906014. The authors thank Prof. Eran Edri, María Ujué González Sagardoy, and Judit Meseguer- Oliver for fruitful discussions and Asylum customer support for help with modifications of the AFM

Photo-Induced Self-Cleaning and Wettability in TiO2 Nanocolumn Arrays Obtained by Glancing-Angle Deposition with Sputtering

In this work, the preparation of regular nanosized columnar structures of titanium dioxide by means of glancing angle deposition with magnetron sputtering (MS-GLAD) followed by thermal annealing is reported. MS-GLAD gives rise to metallic titanium columnar structures with regular width and length that after thermal treatment are fully oxidized to form TiO2 nanocolumns that maintain the morphological features of the original metallic ones. Further functionalization with gold by means of multiple ion cluster source results in well-dispersed Au nanoparticles across the nanocolumns’ surface with a narrow size distribution centered at ca. 8.5 nm. The obtained nanostructures show photocatalytic self-cleaning activity as shown by the elimination of an organic layer deposited on their surface and the detection of hydroxyl radicals. Photoelectrochemical measurements show a better charge separation at the Au/TiO2 interface. In addition, wettability studies show that the degree of hydrophobicity of the surface is increased by the presence of nanocolumns, both in the dark and under UV illumination. This behavior is not modified by the presence of Au nanoparticles on the surface. The obtained results open up interesting implications in the tunability of the properties of nanostructured thin films for this kind of photo-activated application.Financial support from the Spanish Ministry of Science, Innovation, and Universities (MICINN) through the projects SOLPAC (ENE2017-89170-R, MCIU/AEI/FEDER, EU), MAT2014-59772-C2-1-P, and MAT2014-59772-C2-2-P is gratefully acknowledged. The authors also acknowledge the service from the MiNa Laboratory at IMN funded by Comunidad de Madrid (S2018/NMT-4291 TEC2SPACE), MICINN (CSIC13-4E-1794), and the EU (FEDER, FSE). Also, this work has been funded by the regional government of Madrid and European Structural Funds through their financial support to FotoArt-CM program (S2018/NMT-4367), and from Fundación Ramon Areces though the ArtLeaf project. M.B. thanks MICINN for a Juan de la Cierva Incorporación (IJC2019-042430-I) grant.Peer reviewe

On the nature of carbonaceous cosmic dust analogs

IBERTRIVA 2019 X Iberian Conference on Tribology – IBERTRIB, XI Iberian Vacuum Conference - RIVA, Seville, Spain,June 26-28Peer reviewe