New efficient constructive heuristics for the hybrid flowshop to minimise makespan: A computational evaluation of heuristics

This paper addresses the hybrid flow shop scheduling problem to minimise makespan, a well-known scheduling problem for which many constructive heuristics have been proposed in the literature. Nevertheless, the state of the art is not clear due to partial or non homogeneous comparisons. In this paper, we review these heuristics and perform a comprehensive computational evaluation to determine which are the most efficient ones. A total of 20 heuristics are implemented and compared in this study. In addition, we propose four new heuristics for the problem. Firstly, two memory-based constructive heuristics are proposed, where a sequence is constructed by inserting jobs one by one in a partial sequence. The most promising insertions tested are kept in a list. However, in contrast to the Tabu search, these insertions are repeated in future iterations instead of forbidding them. Secondly, we propose two constructive heuristics based on Johnson’s algorithm for the permutation flowshop scheduling problem. The computational results carried out on an extensive testbed show that the new proposals outperform the existing heuristics.Ministerio de Ciencia e Innovación DPI2016-80750-

Compuestos relacionados con la diimida de silicio, método de obtención, y su aplicación en la preparación de un material poroso amorfo

Compuestos relacionados con la diimida de silicio, método de obtención, y su aplicación en la preparación de un material poroso amorfo. La presente invención se refiere a un compuesto de fórmula general: SixM1-xNyHz donde M se refiere al menos a un elemento del grupo formado por germanio, aluminio y galio; x está comprendido entre 0 y 0.5; y está comprendido entre 2 y 4; y z está comprendido entre 2 y 8; dicho compuesto conteniendo enlaces entre los átomos de silicio y átomos de nitrógeno y entre el elemento M y los átomos de nitrógeno. Asimismo, la presente invención se refiere a un método de obtención del compuesto mediante reacción de amonolisis con los compuestos precursores en líquido iónico y amoniaco gaseoso a una temperatura comprendida entre -15ºC y 200ºC. Otro objeto de la invención es el método de preparación de un material poroso amorfo a partir del compuesto descrito, así como el propio material y sus múltiples usosPeer reviewedConsejo Superior de Investigaciones CientíficasB1 Patente sin examen previ

Fatigue properties of nanocrystallized surfaces obtained by high energy shot peening

AbstractAn unconventional method of shot peening aimed to generation of a nanograined layer over the surface of specimens has been applied by means of the standard air blast equipment but using peening parameters essentially different from typical ones. Surface nanocrystallization is verified and affirmed through different experimental procedures. Rotating bending fatigue tests are performed to evaluate the effect of this high energy shot peening and the nanocrystallized layer on fatigue life. First series results are available and the other tests are still in progress

Optimización microestructural de los aceros y fundiciones de alto cromo utilizados en la fabricación de cilindros de laminación

Los cilindro de laminación de los temas de bandas en caliente trabajan bajo unas severas condiciones de servicio, teniendo que soportar fuertes desgastes y fenómenos de fatiga términa que provocan la aparición de grietas superficiales. Las propiedades exigidas a la región superficial de la tabla de estos cilindros (resistencia al desgaste, a la oxidación, al a fátiga térmica, etc.) son muy diferentes del a requeridas en el interior de los mismos (resistencia mecánica y tenacidad especialmente), por lo que se utilizan normalmente los cilindros bimetálicos. La propiedades finales de estos materiales dependen tanto de su composición química como del tratamiento térmico suministrado. En este trabajo de investigación se han pretendido obtener los tratamientos térmicos óptimos de dos calidades diferentes de materiales, un acero alto en cromo y una fundición blanca alta en cromo, utilizados en la capa de los cilindros de los trenes de bandas en caliente. Para ello se ha evaluado el efecto de la variación de las temperaturas y los tiempos de permanencia en el horno sobre la microestrcutra y la dureza de estos productos

A study on the microstructural evolution of a low alloy steel by different shot peening treatments

Recent studies have shown that severe shot peening can be categorized as a severe plastic deformation surface treatment that is able to strongly modify the microstructure of the surface layer of materials, by both increasing the dislocation density and introducing a large number of defects that define new grain boundaries and form ultrafine structure. In this work, conventional shot peening and severe shot peening treatments were applied to 39NiCrMo3 steel samples. The samples were characterized in terms of microstructure, surface roughness, microhardness, residual stresses, and surface work-hardening as a function of surface coverage. Particular attention was focused on the analysis of the microstructure to assess the evolution of grain size from the surface to the inner material to capture the gradient microstructure. Severe shot peening proved to cause a more remarkable improvement of the general mechanical characteristics compared to conventional shot peening; more significant improvement was associated with the microstructural alteration induced by the treatment. Our datas provide a detailed verification of the relationship between shot peening treatment parameters and the microstructure evolution from the treated surface to the core material

Efectos del programa todos envejecemos activos y saludables para el manejo de la depresión en adultos mayores del centro médico militar – 7ma brigada de Lambayeque

El presente trabajo de investigación tiene por objeto determinar los efectos del programa “Todos envejecemos activos y saludables” para el manejo de la depresión en adultos mayores del centro médico militar 7ma Brigada de Lambayeque. Se usó un diseño Pre experimental de un grupo antes y después. El programa fue previamente validado por el método de jueces. La población estuvo constituida por adultos mayores de ambos sexos y alfabetos. El marco teórico del trabajo se sustenta en la teoría cognitiva conductual de Beck, utilizándose para la medición pret y post la escala geriátrica abreviada de Yesavage. Las principales conclusiones son: mejoraron los niveles de depresión, así mismo se observaron cambios significativos que es menor al 0.05 en los siguientes objetivos específicos: Buscar sentirse satisfechos con su vida, fomentar intereses a actividades previas, desarrollar condiciones de mantener un buen ánimo la mayor parte del tiempo, estar en condiciones de cambiar su sentimiento frecuente de amparo o protección, estar en condiciones de superar los problemas de memoria, estar en condiciones de mantener un sentimiento en la actualidad de utilidad o aprecio, estar en condiciones de mantener un sentimiento de plenitud y energía, estar en condiciones de sentimiento de desesperanza ante la condición actual, estar en condiciones de mantener un sentimiento de creencia frente a que los demás personas están mejor.Tesi

Simulations of micro-sphere/shell 2D silica photonic crystals for radiative cooling

Altres ajuts: the CERCA Program/Generalitat de Catalunya.L'article s'ha publicat sota la OSA Open Access Publishing Agreement https://www.osapublishing.org/submit/review/pdf/OSACopyTransferOAAgrmnt(2017-09-05).pdfPassive daytime radiative cooling has recently become an attractive approach to address the global energy demand associated with modern refrigeration technologies. One technique to increase the radiative cooling performance is to engineer the surface of a polar dielectric material to enhance its emittance atwavelengths in the atmospheric infrared transparency window (8-13 ìm) by outcoupling surface-phonon polaritons (SPhPs) into free-space. Here we present a theoretical investigation of new surface morphologies based upon self-assembled silica photonic crystals (PCs) using an in-house built rigorous coupled-wave analysis (RCWA) code. Simulations predict that silica micro-sphere PCs can reach up to 73 K below ambient temperature, when solar absorption and conductive/convective losses can be neglected. Micro-shell structures are studied to explore the direct outcoupling of the SPhP, resulting in near-unity emittance between 8 and 10 ìm. Additionally, the effect of material composition is explored by simulating soda-lime glass micro-shells, which, in turn, exhibit a temperature reduction of 61 K below ambient temperature. The RCWA code was compared to FTIR measurements of silica micro-spheres, self-assembled on microscope slides

Influence of Microstructure and Shot Peening Treatment on Corrosion Resistance of AISI F55-UNS S32760 Super Duplex Stainless Steel

Shot peening is a surface process commonly used in the aeronautic and automotive industries to improve fatigue resistance. Shot peening is proven to be beneficial in the fatigue behavior of components, but rarely has its influence on wear and pitting corrosion resistance been evaluated. In this work, shot peening was performed on AISI F55-UNS S32760 super-duplex stainless steel samples previously submitted to various thermal treatments, to obtain different initial microstructures and properties. Samples have been characterized in terms of microstructure morphology, local chemical composition, microhardness of each constituent phase, and energy dissipation modes. The enhanced properties provided by shot peening has been evaluated through residual stress depth profiles and Full Width at Half Maximum (FWHM) using X-ray diffraction (XRD), surface hardness, surface roughness, and corrosion resistance through salt spray fog tests. The 1400 °C solution thermal treatment was identified as the optimum initial condition, which maximizes the advantages of the shot peening treatment, even pitting corrosion resistance. These results are related to the uniformity of austenite and ferrite in terms of microstructure morphology, micromechanical properties, and alloying elements distribution

Assessment of acute-phase protein response associated with the different pathological forms of bovine paratuberculosis

11 páginas, 1 tabla.In this study, the concentrations of two acute-phase proteins (APPs), haptoglobin (Hp) and serum amyloid A (SAA), were quantitatively assessed in serum samples from cattle naturally infected with paratuberculosis (PTB). APP profiles were compared across 190 animals classified according to the different pathological forms associated with infection: uninfected (n = 59), with focal lesions (n = 73), multifocal lesions (n = 19), and diffuse paucibacillary (n = 11) and diffuse multibacillary lesions (n = 28). Our results showed a significant increase in both APPs in infected animals compared to the control group, with differences depending on the type of lesion. Hp and SAA levels were increased significantly in all infected animals, except in cows with diffuse multibacillary lesions that showed similar values to non-infected animals. The expression pattern of both APPs was similar and negatively correlated with the antibody levels against PTB. These results indicate that the release of Hp and SAA is related to the presence of PTB lesions associated with a high cell-mediated immune response and a lower bacterial load, suggesting that the pro-inflammatory cytokines that are associated with these forms are the main stimulus for their synthesis. These molecules could show some potential to be used as putative biomarkers of PTB infection, particularly for the identification of subclinical animals showing pathological forms related to latency or resistance to the development of advanced lesions.This study was funded by grants RTI2018-099496-B-I00 from the Spanish Ministry of Science and Innovation and LE259/P18 from “Junta de Castilla y León”