Facultad de Ciencias y Tecnología
https://ridda2.utp.ac.pa/handle/123456789/1734
2024-03-28T16:18:52ZMeasuring contribution of infoplazas to internet penetration and use in Panama
https://ridda2.utp.ac.pa/handle/123456789/2822
Measuring contribution of infoplazas to internet penetration and use in Panama
Miller, Norma L.
infoplazas arose in Panama as means to combat the digital gap by providing Internet connectivity to the economically disadvantaged and geographically remote. Yet there is a dearth of information regarding their actual performance. This study constitutes a first attempt to assess the contribution of infoplazas to the diffusion and use of the Internet in Panama. In so doing, this study sets the ground for the development of a more rigorous measurement tool that might obtain better estimates of the dynamics of infoplazas and similar community information centers. Our research suggests that infoplazas account for approximately 7% of Panama's Internet users, that infoplazas might constitute the only connectivity option for at least 25% of users, and that the annual number of serviced visits might be considerably higher than the official figure. This study also draws attention to a number of challenges faced by the Infoplaza Project.
infoplazas arose in Panama as means to combat the digital gap by providing Internet connectivity to the economically disadvantaged and geographically remote. Yet there is a dearth of information regarding their actual performance. This study constitutes a first attempt to assess the contribution of infoplazas to the diffusion and use of the Internet in Panama. In so doing, this study sets the ground for the development of a more rigorous measurement tool that might obtain better estimates of the dynamics of infoplazas and similar community information centers. Our research suggests that infoplazas account for approximately 7% of Panama's Internet users, that infoplazas might constitute the only connectivity option for at least 25% of users, and that the annual number of serviced visits might be considerably higher than the official figure. This study also draws attention to a number of challenges faced by the Infoplaza Project.
2004-12-01T00:00:00ZEffectiveness of natural antioxidants in sunflower oil
https://ridda2.utp.ac.pa/handle/123456789/2819
Effectiveness of natural antioxidants in sunflower oil
Carelli, Amalia A.; Franco, Indira C.; Crapiste, Guillermo H.
The antioxidant activity of ∝- and δ-tocopherol, citric acid, ascorbic acid and ascorbyl palmitate was investigated in sunflower oil containing naturally occurring tocopherol. The effectiveness of natural antioxidants in sunflower oil was monitored by the accelerated oxidative stability test Rancimat and oxidation development during storage under different conditions. Samples in storage experiments were periodically removed and analyzed for peroxide value, p-anisidine value, total content and distribution of polar compounds, and residual naturally occurring tocopherol. The effectiveness of each antioxidant was strongly dependent on temperature and the testing method. While ascorbic acid appears to be the most effective antioxidant according to the Rancimat oxidative stability index, δ-tocopherol shows improved performance when considering storage experiments.
The antioxidant activity of ∝- and δ-tocopherol, citric acid, ascorbic acid and ascorbyl palmitate was investigated in sunflower oil containing naturally occurring tocopherol. The effectiveness of natural antioxidants in sunflower oil was monitored by the accelerated oxidative stability test Rancimat and oxidation development during storage under different conditions. Samples in storage experiments were periodically removed and analyzed for peroxide value, p-anisidine value, total content and distribution of polar compounds, and residual naturally occurring tocopherol. The effectiveness of each antioxidant was strongly dependent on temperature and the testing method. While ascorbic acid appears to be the most effective antioxidant according to the Rancimat oxidative stability index, δ-tocopherol shows improved performance when considering storage experiments.
2005-06-27T00:00:00ZPreparación de Películas de Óxidos de Estaño Como Sensores de Gases
https://ridda2.utp.ac.pa/handle/123456789/2818
Preparación de Películas de Óxidos de Estaño Como Sensores de Gases
Chacón, Manuel; Abrego, Ildemán; Watson, Amanda; Ching, Eleicer
Se obtuvieron películas delgadas de Óxido de Estaño (SnO2) por el método de química líquida a partir de una solución precursora de Cloruro de Estaño IV (SnCl4). Las muestras fueron depositadas sobre sustrato de vidrio utilizando un porcentaje de dilución de 60 % de la solución precursora sinterizadas a diferentes temperaturas.
Las superficies de las películas fueron caracterizadas morfológicamente mediante Microscopía Electrónica de Barrido (MEB) y se describen los tamaños de granos, la presencia de fisuras (cracking) y homogeneidades entres otras cosas. Además, se estudió la capacidad sensora de las muestras a través de las medidas de resistencia eléctrica en función del tiempo para diferentes volúmenes de vapor de agua.
Se obtuvieron películas delgadas de Óxido de Estaño (SnO2) por el método de química líquida a partir de una solución precursora de Cloruro de Estaño IV (SnCl4). Las muestras fueron depositadas sobre sustrato de vidrio utilizando un porcentaje de dilución de 60 % de la solución precursora sinterizadas a diferentes temperaturas.
Las superficies de las películas fueron caracterizadas morfológicamente mediante Microscopía Electrónica de Barrido (MEB) y se describen los tamaños de granos, la presencia de fisuras (cracking) y homogeneidades entres otras cosas. Además, se estudió la capacidad sensora de las muestras a través de las medidas de resistencia eléctrica en función del tiempo para diferentes volúmenes de vapor de agua.
2009-06-01T00:00:00ZRoughness measurement of paper using speckle
https://ridda2.utp.ac.pa/handle/123456789/2817
Roughness measurement of paper using speckle
Pino, Abdiel; Pladellorens, Josep; Cusola, Oriel; Caum, Jesus
We present a method of measure of the roughness of the paper based on the analysis of a speckle pattern on the surface. Images of speckle over the surface of paper are captured by means of a simple configuration using a laser, beam expander, and a camera charge-coupled device (CCD). Then we use the normalized covariance function of the fields, leaving the surface to find the roughness. We compare the results obtained with the results obtained with a confocal microscope and the Bendtsen method that is a standard of the paper industry. This method can be considered as a noncontact surface profiling method that can be used online.
We present a method of measure of the roughness of the paper based on the analysis of a speckle pattern on the surface. Images of speckle over the surface of paper are captured by means of a simple configuration using a laser, beam expander, and a camera charge-coupled device (CCD). Then we use the normalized covariance function of the fields, leaving the surface to find the roughness. We compare the results obtained with the results obtained with a confocal microscope and the Bendtsen method that is a standard of the paper industry. This method can be considered as a noncontact surface profiling method that can be used online.
2011-09-02T00:00:00Z