Browsing Dyna by Title
Now showing items 1560-1579 of 1620
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UAREI: A model for formal description and visual representation /software gamification
The paper presents the UAREI (User-Action-Rule-Entities-Interface) model for formal specification of software gamification, and the UAREI visual modelling language for graphical representation of game mechanics. A case of ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Ultrasonic sensor for the presence of oily contaminants in water
The measurement of the reflection coefficient of ultrasonic shear-waves at the solid-liquid interface is a technique employed for the measurement of the viscoelastic properties of liquids. An interesting property of the ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Unbalanced magnetron sputtering system for producing corrosion resistance multilayer coatings
In this work, an unbalanced magnetron sputtering system which allows for the production of corrosion resistance multilayer coatings is described. The major advantage of this system is that it combines features such as a ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uncoupling laminar conjugate heat transfer through chebyshev polynomial
The conjugate heat transfer process of cooling a horizontal plate at the leading edge, in steady state condition, was solved considering the fluid flowing in laminar condition and hydro dynamically developed before interacting ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Understanding finger postures when touching targets on the touchscreen of mobile devices1
This paper presents the results of a preliminary study on the interaction of the fingertip and a mobile device’s touch screen. The objective of this study is to identify the finger postures that will be included in the ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Unified model of shear modulus degradation curves in sand of guayuriba river
The purpose of this paper is to analyze the applicability of two unified model of shear modulus degradation curves in the sand of Guayuriba River (Department of Meta, Colombia). To achieve the objective, it was performed ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uplift force and momenta on a slab subjected to hydraulic jump
As part of the search for safe and economic design criterion to line slabs of stilling basins, the present study is one of the first to calculate the center of pressure, uplift forces, and momenta from a spatiotemporal ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Use of a multi-objective teaching-learning algorithm for reduction of power losses in a power test system
This paper presents a multi-objective teaching learning algorithm based on decomposition for solving the optimal reactive power dispatch problem (ORPD). The effectiveness and performance of the proposed algorithm are ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Use of residual powder obtained from organic waste to partially replace cement in concrete
The main objective of this research is to investigate the feasibility of using the residual powder obtained from organic waste to replace a part of Portland cement during concrete production. The chemical and physical ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Use of the order statistics when predicting pile foundation failure probability
The study of pile foundation reliability and safety is based on the analysis of the probabilistic moments, average and coefficient of variation that are associated with the resistant surface. This surface imposes the ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Use of white rot fungi in the degradation of an azo dye from the textile industry
Textile industry effluents—a complex mix of chemicals, among which colorants are of particular concern—impose great environmental challenges. In this study, a full 23 factorial design was used for determining the best ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Using dispersion measures for determining block-size in motion estimation
Video compression techniques remove temporal redundancy among frames and enable high compression efficiency in coding systems. Reduction of temporal redundancy is achieved by motion compensation. In turn, motion compensation ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Using the astm e 274 skid trailer data to characterize pavement friction behavior with respect to the traveling speed and the wheel slip ratio
Knowing the 3-D behavior of friction coefficient (µ) vs. traveling speed (v) and wheel slip ratio (s) on runway and highway pavements can facilitate the modern pavement engineers’ job to a great extent. However, current ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Using waste energy from the Organic Rankine Cycle cogeneration in the Portland cement industry
Cement production is intensive in terms of energy consumption. An analysis of the resources involved in manufacturing clinker needs a corresponding mass and energy balance. This balance may indicate the existence of residual ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uso de biosólidos como reactivo espumante en procesos de flotación: caracterización física y química
La flotación espumosa usa diversos reactivos, orgánicos e inorgánicos, para aumentar el rendimiento y selectividad del proceso. La flotación utiliza sustancias tensoactivas que se adsorben en la interfase aire/agua. Como ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uso de labview para sistemas de control en ingeniería química
Se implementó un sistema de control para una planta multipropósito el cual consta de control de nivel, control de temperatura y control de presión. Se desarrolló una interfaz en LabView 9.1 para una mejor visualización de ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uso de métodos químicos para la obtención de sensores de gas del sistema sn-sb
Los sensores de gas basados en Óxidos semiconductores presentan un cambio en la resistencia cuando son expuestos a ciertos gases. El óxido de estaño, SnO2, es el compuesto más utilizado en la fabricación de sensores de ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uso de patrones de difracción de luz láser y análisis de imagenes para diferenciación de tres tipos de colonias bacterianas
La diferenciación rápida de colonias bacterianas es esencial en muchos campos industriales, científicos y de salud humana y animal. Generalmente esa diferenciación se logra por técnicas microscópicas, bioquímicas o genéticas ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uso de test de lixiviacion para determinar la migracion de contaminantes en morteros de sustitución con residuos de catalizador de craqueo catalitico (fcc)
En este estudio se evalúa la viabilidad ambiental en la utilización de dos residuos de catalizador de craqueo catalítico procedentes de fuentes diferentes (Colombia y España), como sustitución parcial del cemento Portland, ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna. -
Uso potencial de ceniza de lodo de depuradora como sustitución de árido fino en bloques de hormigón prefabricados
El presente artículo se centra en la valorización de las cenizas de lodo de depuradora adicionadas en bloques de hormigón prefabricados, por tanto, en una matriz a base de cemento Portland con características particulares ...Universidad Nacional de Colombia Revistas electrónicas UN Dyna.