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DIALNET OAI Articles (803.276 recursos)

Dialnet (Difusión de Alertas en la Red) es una plataforma de recursos y servicios documentales, cuyo objetivo fundamental se centra en mejorar la visibilidad y el acceso a la literatura científica hispana a través de Internet.

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Mostrando recursos 1 - 20 de 13.307

  1. Marcado con láser sobre cerámica vidriada por aporte superficial de un pigmento de cobalto

    Gómez, Maryory Astrid; Restrepo, José William
    Laser materials processing has great application to industrial scale, to print graphic patterns on ceramics surfaces. The fast implementation of this process is due to the fact that, with respect to the conventional baking process, has advantages, such as: heat is concentrated only in the radiated zone that involves a smaller energy consumption without affecting significantly the rest of the piece, graphic patterns with of highly spatial resolution are obtained, it permits to introduce changes during the process without requiring long stops, and low or almost none generation of residues. In this study the results obtained from Nd:YAG (λ=1064 nm)...

  2. Relación de las curvas de energía específica y pendiente de fricción con las zonas de flujo libre en canales

    Mejía, Francisco Jaime
    One objective of an introductory course of open-channel flow is the analysis of gradually varied flow profiles. This paper shows a teaching-learning strategy that might improve the university practices for teaching hydraulics. It is well known the depth-specific energy curve (y-E) for describing and interpreting open-channel flow hydraulics. It is proposed to complement that curve with the depth-energy slope curve (y-sf). By using a graphic comparison, it aims to illustrate the concepts of the subcritical, critical and supercritical flow concepts and, on the other hand, the subnormal, normal y supernormal flow concepts. This way, it is proposed to explain the...

  3. Annual and diurnal cycles of the inverse relation between plant transpiration and carbon sequestration

    Moreno, Hernán Alonso
    Understanding biogeochemical cycles and especially carbon budgets is clue to validate global change models in the present and near future. As a consequence, sinks and sources of carbon in the world are being studied. One of those sinks is the non-well known behavior of the planet vegetation which involves the processes of photosynthesis and respiration. Carbon sequestration rates are highly related to the transpiration through a molecular diffusion process occurring at the stomatal level which can be recorded by an eddy covariance micrometeorological station. This paper explores annual and diurnal cycles of latent heat (LE) and CO2 net (FC) fluxes...

  4. Sistemas de información geográfica para el análisis de la distribución espacial de la malaria en colombia

    Molina, Adriana María
    Malaria is a preventable disease that persists as one of Colombia´s major public health problems. An efficient allocation of resources for malaria control requires the identification of endemic zones and their simultaneous and systematic characterization in several aspects. Geographic Information Systems (GIS) technology was used to bring together data from different sources for a recent period and develop various spatial analyses in the five endemic zones identified. Information was organized in synthesis cards that allow general view of each endemic zone, making it easier to have a general idea about the conditions of vulnerability of population at risk, incidence for...

  5. Directrices para la construcción de artefactos de persistencia en el proceso de desarrollo de software

    Quintero, Juan Bernardo; Hernández, Diana María; Yanza, Andrea
    Data storage is a process required in almost every information system nowadays; the treatment given to databases during the software development can be a determining factor in order to achieve good performance of a resulting system. The accelerated technological evolution and the progress of the software enterprises have given rise to diverse modeling strategies and several data access techniques. This work explains the practical and conceptual references for the construction of products related to databases, the access techniques to them and the handling that so-called persistence artifacts have at an industrial level.

  6. Cómo llegan a la definición de la estrategia las empresas localizadas en el Valle de Aburrá

    Alejandro, Ramos
    This paper is focused on the understanding of the variables and determinants of the ideas about strategy and how to reach it, that were expressed by people who work in companies that are located in the Aburra Valley (Medellin, Colombia). The methodology used in the research had an exploratory character, focused on qualitative aspects and was conducted by the completion of a questionnaire with open questions, which final results and observations were afterwards analyzed. After the integration of the results, these were contrasted with recognized authors, such as, Igor Ansoff, Michael Porter, Alfred Chandler, Henry Mintzberg, Richard Whittington, to mention...

  7. Análisis de la ingeniería de requisitos orientada por aspectos según la industria del software

    Londoño, Luis Fernando; Anaya, Raquel; Tabares, Marta Silvia
    Applying good practices to manage software requirements is a basic condition to obtain quality products. Therefore, it is important that software companies maintain a constant research around of new techniques and mechanisms to improve requirements activities such as elicitation, specification, and modeling. In this paper, we present a study of most representative aspect-oriented requirement approaches in order to analyze the way how these could support issues confronted by software companies during early stages of the lifecycle. Thus, we make a comparative analysis among approaches under criteria defined such as scope, traceability, requirements composition, conflict management, mapping, validation-verification, and scalability. Results...

  8. Un método de ingeniería inversa de código java hacia diagramas de secuencias de UML 2.0

    Zapata Jaramillo, Carlos Mario; Ochoa, Óscar Andrés; Vélez, Camilo
    Software reverse engineering seems to be the process for helping software quality assurance and documentation in applications with low-quality analysis and design models. It also helps for decreasing maintenance cost and time. Currently, some CASE tools and research proposals assist analysts to develop reverse engineering process with UML diagrams as a result (especially class and sequence diagram). Some of them have reached experimental phases. Some others are focused more on class diagram and less on sequence diagram. A third group of CASE tools and proposals obtains sequence diagram, but the resulting diagram lacks some of the elements of the UML...

  9. Información, conocimiento y desarrollo económico

    Lochmüller, Christian
    Production of information and knowledge is booming. Access to and availability of information and knowledge are better than ever before. However, we can observe companies and countries which use existent knowledge more effectively than others. This paper describes the role of information and knowledge in economic theory, discusses the difficulties of transferring knowledge and analyses the fact that in many cases created knowledge does not get introduced to markets. Innovation and entrepreneurship are the missing link that should be strengthened in order to transform knowledge into new products, processes, services, and markets. That is why changes are necessary within companies...

  10. Calidad del agua de las quebradas la cristalina y la risaralda, san luis, antioquia

    Arango, María Cecilia; Álvarez, Luisa Fernanda; Arango, Gloria Alexandra; Torres, Orlando Elí; Monsalve, Asmed de Jesús
    The streams La Cristalina and La Risaralda are the water sources for the urban area of the Municipality of San Luis, Antioquia. The intention of this study was to develop a map of water quality that serves as base as comparison of the evolution of the streams and allows the high-priority destination of the resources of the Municipality in the improvement of those more critical sections. In order to determine the quality of the water, parameters and some characteristics of the stream that can alter the quality of the water were measured, like substrate of the bed, cover of banks,...

  11. Evaluación del mercado de opciones sobre tasas de cambio: Perspectivas para una mejor utilización

    Ochoa, Iván Darío; González, Cristina
    Colombia has to have a financial market that fits the needs of its increasingly internationalized economy. That means that a financial derivate market has to be developed. This includes a very deep options market in which forex options be widely dealt with in order to take advantage of the multiple benefits of this instrument specially for hedging purposes since the currency exchange risk is more and more threatening in a globalized world. Options are not very well known in Colombia and there is little information about them. They are only treaded in the over the counter (OTC) market since there...

  12. UNC-Analista: Hacia la captura de un corpus de requisitos a partir de la aplicación del experimento mago de oz

    Zapata Jaramillo, Carlos Mario; Palacio, Carolina; Olaya, Natalí
    Requirements elicitation is one of the most important phases in software development process. A good requirements understanding can lead to better software products, achieving satisfaction of stakeholder needs. However, requirements-capture process is sometimes difficult for analysts, because of the face-to-face character of the meetings required for it and because of difficulties of people for expressing clearly their ideas. In this paper we present UNC-Analista, a proposal for Wizard-of-Oz experiment focused on the design of a dialogue-controlled system for helping the analyst labor in the requirements elicitation process. With this system will be possible to capture a requirements corpus, for leading...

  13. Producción de biomasa y exopolisacáridos de grifóla frondosa bajo cultivo sumergido utilizando fuentes de carbono no convencionales

    Zapata, Paula; Rojas, Diego; Fernández Ossa, Carlos Eduardo; Ramírez, David Alejandro; Orjuela, Viviana; Arroyave Gómez, Diana Marcela; Atehortúa, Lucía; Restrepo, Gloria; Gómez Vargas, Mónica Tatiana
    Grifóla frondosa is a Basidiomycete fungus edible and medicinal, it produces polysaccharides such a glucans (β-1,6 and β-1,3) with anti-tumor and inmuno-stimulating activity. For this work, the aim was evaluate the incidence of different carbon sources (FC) in biomass and exo-polymer (EPS) production, under submerged culture conditions, by using a factorial statistical design with two factors: carbon source (FC(1-7)) and medium (MB and MS). The maximal yield of mycelial biomass (21,10 ± 0,82) g/l and the maximal yield in EPS (6,53 ± 0,14) g/l was achieved by using the MB medium supplemented with FC4. Besides, it was possible to develop...

  14. Modélisation conceptuelle d´une unité de fabrication microélectronique

    Montoya Torres, Jairo Rafael
    The modelling of industrial systems is a very hard task because of both the number and diversity of parameters to take into account, and the complex relations between these parameters. In this paper, we are interested on the study of a fully automated Integrated Circuit (IC) semiconductor manufacturing plant (fab). In the semiconductor literature, fab behaviour analysis has very often been performed using discrete-event simulation models, but little work has been devoted to the conceptualisation of the modelling approach. Other works focus on the analysis of single parts of the fab, by simplifying the relations between its components. In such...

  15. Diseño de una metodología de selección de sitios para monorrellenos de lodos papeleros

    Quinchía, Adriana María; Irwin, Susan; Uribe Ramírez, Ana María
    The wastewater treatment at paper industry that uses recycled fibers as one of its raw materials generates a sludge rich in cellulose fibers, which once dehydrated is called "paper waste". This waste has become an environmental problem because of its high generation rate. Although several alternatives of valorization have been studied, in Medellin none of them has been implemented on an industrial scale; the necessity is still there, that is why the land disposal of this waste appears as the most immediate way to manage it. Combined with the problem of disposition, it is the selection of the suitable site...

  16. Energía de enlace de excitones en pozos cuánticos de Gaas/Ga1-xal xas

    Aristizabal U., Parménides; Restrepo A., Ricardo; Ospina M., Walter; Duque Daza, Carlos Alberto
    The use of low dimensional structures is a key technological element in the creation of new quantum functional devices in the development of the next generation of the electronic, photonic, and spintronic integrated circuits and many other nanoscaled devices that are necessary for the information society of 21st century. One of the most important optical properties is the photoluminescence produced by agents as impurities and excitons in GaAs quantum wells, wires, and dots with nanometric dimensions under the influence of electric and magnetic fields and external pressures. The binding energy for the first three excitonic states in GaAs/Ga1-xA1xAs quantum wells...

  17. Influencia de la fatiga muscular en la señal electromiográfica de músculos estimulados eléctricamente

    Fernández, Juliana M.; Acevedo, Rubén C; Tabernig, Carolina B
    The functional electrical stimulation is a technique of rehabilitation for patients with paralysis that restitutes the lost motor function, which can be studied by means of the registry of the electrical activity of muscles or electromyographic signal. When the muscle is being stimulated, this signal is a wave of synchronous depolarization with the stimulus, which receives the name of M-wave. This wave is the main indicator of the answer of the muscle to the electrical stimulus and presents changes in its spectral and morphological characteristics when the fatigue phenomenon appears. The muscular fatigue limits the use of systems of functional...

  18. Inmunosensores piezoeléctricos: Revision general y su aplicación en el análisis de pesticidas

    Ocampo, Aquiles; March, Carmen; Montoya, Ángel
    A bibliographic review about the main aspects concerning the development of immunosensors is presented in this article, as well as some of the experimental results in an application in the analysis of carbaryl plaguicide that illustrates the analytical methodology and the expected results. The quartz crystal microbalance immunosensor (QCM), known as piezoelectric immunosensor, is an analytical system which combines an immunoreagent as the biologic component, a quartz crystal transducer with an immobilized antigen or antibody on its surface, coupled to an information processing system. Due to its simplicity, convenience, low cost, accuracy, stability, and real time response, this device has...

  19. Fabricación y caracterización de una matriz tridimensional de hidroxiapatita macroporosa para aplicación en ingeniería de tejidos óseos

    Rincón, Marcela; Rodríguez Martínez, Jairo Alejandro; Londoño López, Marta Elena; Echevarría, Alejandro
    La ingeniería de tejido óseo surge como una nueva opción para el tratamiento de muchos tipos de afecciones, entre ellas las enfermedades óseas, permitiendo resolver múltiples problemas en el área médica. El desarrollo de una matriz de hidroxiapatita para cultivo de células óseas permitirá contar con otra alternativa para enfrentar las enfermedades causadas en el hueso y articulaciones que frecuentemente llevan a la discapacidad en las personas. En este trabajo se obtuvo hidroxiapatita sintética por la ruta de precipitación a partir de fosfato de amonio NH4H2PO4 y nitrato de calcio Ca(NO3)2.4H2O. Se formaron matrices en las cuales se indujo macroporosidad...

  20. Metodología para evaluación de la condición de corrientes urbanas

    Barros, Juan Fernando; Vallejo, Luz Eliana
    A methodology for the evaluation of the condition of urban streams is proposed. The methodology integrates field data, historical information and technical analysis; it could be applied to the hydraulic component of the physical subsystem to comply with the ordering plans for watersheds. Pointers to measure the condition of the streams and the watershed are defined, the connection between portions of the streams with different hydraulic capacity conditions is analyzed and a multicriteria analysis is developed. This analysis compiles all the information gathered and identifies the most critical points of the hydraulic network based on three basic criteria: field evaluation,...

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