Obtaining relief structures in silver halide materials

Se registraron rejillas de difracción de transmisión en película AGFA 8E75, tratadas químicamente bajo procesos convencionales con D-19 + ferrocianuro de potasio y una técnica de procesamiento químico desarrollada para película PE-2, para la obtención de franjas con relieve. Las estructuras holográficas fueron medidas topográficamente mediante la técnica de microscopía de fuerza atómica en modo no contacto (AFM-NC) y se observan cambios en las profundidades bajo variaciones en las exposiciones y la fotoquímica utilizada. Se encuentra que el mejor rendimiento en términos de profundidad de relieve obtenido está dado por un proceso tradicional con el cual se alcanzaron profundidades entre 0,15 y 0,3 m para densidades ópticas y frecuencias espaciales bajas. En este trabajo evaluamos la posibilidad de obtener matrices de relieve en haluros de plata para procesos de réplica de hologramas.Diffraction transmission gratings were recorded in AGFA-8E75 film, chemically treated under processes with D-19 + potassium ferrocyanide and a chemical processing technique proposed for PE-2 film to obtain embossed stripes. Holographic structures were measured topographically by the technique of atomic force microscopy in noncontact mode (NC-AFM) and we observe changes in the depths under variations in exposures and used photochemistry. We find that the best performance in terms of relief depth obtained is given by the conventional process which reached depths between 0.15 m and 0.3 m for spatial frequencies of the order of 400Se registraron rejillas de difracción de transmisión en película AGFA 8E75, tratadas químicamente bajo procesos convencionales con D-19 + ferrocianuro de potasio y una técnica de procesamiento químico desarrollada para película PE-2, para la obtención de franjas con relieve. Las estructuras holográficas fueron medidas topográficamente mediante la técnica de microscopía de fuerza atómica en modo no contacto (AFM-NC) y se observan cambios en las profundidades bajo variaciones en las exposiciones y la fotoquímica utilizada. Se encuentra que el mejor rendimiento en términos de profundidad de relieve obtenido está dado por un proceso tradicional con el cual se alcanzaron profundidades entre 0,15 y 0,3 m para densidades ópticas y frecuencias espaciales bajas. En este trabajo evaluamos la posibilidad de obtener matrices de relieve en haluros de plata para procesos de réplica de hologramas.EAFIT Universit

Ajuste de la eficiencia de difracción para el registro de hologramas a color de alta calidad

In this article, we report the experimental values of required exposure to obtain the maximum diffraction efficiencies in PFG-03C Slavich film on independent recordings and RGB multiplexed recordings -- Also, color adjustments by modifying wavelength channels contribution on reflection diffraction gratings, and color composition changes on Denisyuk holograms observed by using different spectral compositions light sources were studied and presentedEn este artículo se obtienen los valores experimentales de exposición requeridos para obtener las máximas eficiencias de difracción en película Slavich PFG-03C, sobre registros independientes y registros multiplexados RGB -- También fueron ajustadas las contribuciones porcentuales de cada color sobre redes de difracción por reflexión para observar correspondencia en la composición del color con estas contribuciones RGB sobre hologramas tipo Denisyu

Consenso colombiano de atención, diagnóstico y manejo de la infección por SARS-COV-2/COVID-19 en establecimientos de atención de la salud Recomendaciones basadas en consenso de expertos e informadas en la evidencia

The “Asociación Colombiana de Infectología” (ACIN) and the “Instituto de Evaluación de Nuevas Tecnologías de la Salud” (IETS) created a task force to develop recommendations for Covid 19 health care diagnosis, management and treatment informed, and based, on evidence. Theses reccomendations are addressed to the health personnel on the Colombian context of health services. © 2020 Asociacion Colombiana de Infectologia. All rights reserved

One sixth of Amazonian tree diversity is dependent on river floodplains

Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.Naturali

Corporate entrepreneurship and entrepreneurial orientation: The impact on managing capabilities for innovation

In last decades, Corporate Entrepreneurship and Entrepreneurial Orientation have been considered as important sources of sustainable competitive advantages and economic growth. Most empirical studies show a high relationship between both concepts, and have attracted an increasing attention in the field of strategic management and entrepreneurship. This study is the preliminary conceptual research result of doctoral dissertation, toward developing the needed theoretical base in single case study design in a Colombian company of the automotive sector. The objective of this article is to analyze the relationships between two constructs and the impact on managing capabilities for innovation. Findings reveal the importance of institutional factors (strategy, structure and culture) in relation to entrepreneurial orientation (innovativeness, proactiveness, and risk-taking) as key elements that foster the ability to capture opportunities in entrepreneurial firms. Finally, results contribute to develop the existing literature and provide new insights to managers who make decisions to promote entrepreneurship within organizations. © 2018 Portland International Conference on Management of Engineering and Technology, Inc. (PICMET)

Interactivity Model 2.0: Social communication dynamics in organizational contexts

This article presents the Interactivity Model 2.0, which aims to support the communicative process of knowledge transfer 2.0 developed in organizations that follow a social business model. This model has its origin in SECI and Ba interaction models and in the Open Communication Interactivity Model. This study defines Interactivity building on two concepts: role and interaction. The study considers role as actors taking part in Knowledge Transfer Process 2.0, and interaction as the process of communication that enables a transfer. The research tests this model through a case study at a Colombian Information Technology Company. The results show the changes of the communicative process in social settings and allow the identification of a message, a role, the direction and control of a message, and the knowledge contributions of the various actors of the Knowledge Transfer Process 2.0. © 2016

Monocolor and color holography of pre-Hispanic Colombian goldwork: A way of Colombian heritage appropriation

Optically indistinguishable copies of 3D real objects or holograms are known to be suitable to replace exhibited artistic pieces in museums. In this paper, we discuss holography as an alternative to protect, share and preserve finely crafted gold pieces belonging to the indigenous treasure inherited by Colombians. We present high diffraction efficiency monocolor and color holograms of native goldwork. As reference objects and proof of concept, we use replicas of the renowned and emblematic Poporo Quimbaya, pre-Hispanic gold pendants and anthropomorphic gold pieces. We report experimental details to deal with different types of commercial holographic recording materials, as for example, PFG-03M and PFG- 03C silver halides or C-RT20 photopolymers. And its general feasibility for reproducing high-quality holograms suitable for museum exhibitions or traveling art-collections. Copyright © 2018 SPIE. Downloading of the abstract is permitted for personal use only