Search

Femtosecond ultra-short laser pulses can induce various micro- and nanostructural changes in the surface of stainless steel, paving the way for new functionalities in the application of these materials. In this work, UV, visible, and IR femtosecond laser pulses have been utilized on ferritic stainless steel under differing conditions of fluence, pulses per spot and hatch distance. These variables resulted in various compositional and micro- and nanostructural changes on the steel surfaces. The texturing processes which originate these changes can be meticulously designed by selecting the appropriate strategy and laser parameters, leading to Laser-Induced Periodic Surface Structures (LIPSS) and other potential morphologies. A significant problem to consider during the laser treatment of stainless-steel surfaces is the effect that these microstructural modifications, induced by the ultra-short pulses, can have on the corrosion behavior and the brightness of the surface. On one hand, a detailed study of the effect that these treatments can have on the corrosion resistance of the stainless steel under investigation has been conducted. The study shows that under specific conditions, treatments with ultra-short laser pulses maintain the corrosion resistance of the surfaces. On the other hand, the study of the surface brightness after laser treatments, as measured by the Light Reflectance Value (LRV), shows that brightness is only slightly decreased (less than 10 %) for samples where Surface Density of Applied Energy (SDAE) is lower than 2 J/cm2. Furthermore, the diffuse LRV is increased in every textured sample due to the presence of ripples.

Este análisis responde a un estudio cualitativo sobre la eficacia del principio jurídico de la participación ciudadana en la implementación de las políticas públicas educativas en Colombia a nivel básico. Se utiliza una metodología de investigación cualitativa y los resultados permiten contrastar los principales hallazgos bibliográficos y documentales, a partir de un enfoque socio-jurídico el cual pretende reconocer la eficacia del precepto de la participación por parte de los llamados destinatarios de la norma jurídica consagrada en la Constitución Política como en la ley. La reflexión propuesta se hace desde la perspectiva asociada con los procesos de reforma del Estado en América Latina de mediados de la década de 1990, los cuales pretenden implementar estrategias para democratizar y generar confianza en la gestión pública. Este análisis teórico permitió evidenciar los principales desafíos que debe afrontar la participación ciudadana frente a las prácticas institucionales, sobre todo locales, encargadas de la implementación de las políticas públicas de calidad de la educación en el nivel básico

There is widespread concern about the increase in cases of human and animal infections caused by pathogenic Vibrio species due to the emergence of epidemic lineages. In Colombia, active surveillance by the National Institute of Health (INS) has confirmed the presence of Vibrio ; however, in routine surveillance, these isolates are not genomically characterized. This study focused on the pangenome analysis of six Vibrio species: V. parahaemolyticus , V. vulnificus , V. alginolyticus , V. fluvialis , V. diabolicus and V. furnissii to determine the genetic architectures of potentially virulent and antimicrobial resistance traits. Isolates from environmental and clinical samples were genome sequenced, assembled and annotated. The most important species in public health were further characterized by multilocus sequence typing and phylogenomics. For V. parahaemolyticus , we found the virulent ST3 and ST120 genotypes. For V. vulnificus , we identified isolates belonging to lineages 1 and 2. Virulence gene homologues between species were found even in non-pathogenic species such as V. diabolicus . Annotations related to the mobilome, integrative mobile and conjugative elements and resistance genes were obtained from environmental and clinical isolates. This study contributes genomic information to the intensified surveillance program implemented by the INS to establish potential sources of vibriosis in Colombia.