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  • Publicación
    Anisotropy and humidity effect on tensile properties and electrical volume resistivity of fused deposition modeled acrylonitrile butadiene styrene composites
    (Pontificia Universidad Católica del Perú, 2017)
    Adauto Ureta, Anaís Elena
    In the present thesis, the influence of anisotropy and humidity in the tensile properties and electrical volume resistivity of Acrylonitrile Butadiene Styrene/Carbon Nanotubes and Acrylonitrile Butadiene Styrene/Micro Carbon Fibers manufactured by Fused Deposition Modeling 3D printing was studied. To study the influence of the anisotropy three different layer printing orientations were compared (0°, 45° and 45°/-45°) in a layer height of 0.2 mm. It was concluded that the influence of anisotropy is important on Acrylonitrile Butadiene Styrene/Micro Carbon Fibers tensile behavior due to relation that exist between the performance/resistance and the alignment of the reinforcement. On the other hand, no significant influence was found on the Acrylonitrile Butadiene Styrene/Carbon Nanotubes. On the electrical volume resistivity, no significant variation was found on the Acrylonitrile Butadiene Styrene/Carbon Nanotubes by the anisotropy of the layers. Acrylonitrile Butadiene Styrene/Micro Carbon Fibers could not be essayed because of the high resistance of the composite.
  • Publicación
    Preparation and characterization of sputtered hydroxyapatite thin films
    (Pontificia Universidad Católica del Perú, 2018)
    Farfán Lira, José Enrique
    In this work, hydroxyapatite (HAp) thin films were fabricated using two different sputtering techniques: Radio frequency magnetron sputtering and ion beam sputtering. In the first case, the films were grown on Ti-6Al-4V substrates using a high-purity commercial HAp target, obtaining a thickness ~200 nm. For the second method, the film were grown on pure titanium substrates using a self-produced HAp target. This target was fabricated with powders (Ca/P = 1.628, sintered and crushed). Here, the thickness of the fabricated film was ~300 nm. The sintering tests for the target fabrication were carried out using two different heating regimens at a maximum temperature of 1200 °C (holding time of 2h and 4h) using various additives. As additives, water (H2O), polyvinyl alcohol (PVA) and polyethylene glycol (PEG) were used to improve the mechanical strength of the green discs. The as-deposited films were amorphous in both cases. Therefore, the films were annealed to increase the crystallinity. Annealing was performed in air for 2h at temperatures: 400, 600 and 800 °C for RF-magnetron sputter samples; 600 and 800 °C for ion beam sputter samples. The result of the films shows in both cases that the crystallinity of HAp was improved only for the annealed samples fabricated with ion beam sputtering at 800 °C. In both cases energy dispersive X-ray spectroscopy measurements show a decrease in Ca/P ratio with increasing the temperature. Hardness results revealed an increase in this with the increase in temperature possibly due to the formation of titanium oxide. The roughness for the fabricated films with the RFmagnetron sputtering increases till an annealing temperature of 600 °C and then decreases till 800 °C, while the roughness for the fabricated films with ion beam sputtering is higher in the as-deposited samples and then this is reduced by increasing the annealing temperature.
  • Publicación
    Identificación de modelos institucionales público-privado-academia para la mejora de la gestión de la CTI
    (Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concytec, 2022-11)
    Delich, Valentina
    Aborda una exploración de un modelo de vinculación para el sector público que sea aplicable a los principales actores de las Universidades – Empresas – Gobierno (U-E-G). Los sistemas de innovación, modelos de vinculación, tipos de vinculación y el momento en el que nos encontramos como país, son palancas que favorecen el intercambio o todo lo contrario. Por lo que, se hizo un recorrido por la realidad de cada sector desde la mirada de la vinculación, es decir, se hace una referencia desde la universidad, la empresa y el gobierno, para luego analizar de modo bilateral: empresa – universidad, universidad – gobierno y empresa gobierno, terminando con la interacción tripartita universidad – empresa - gobierno. Todas las combinaciones entrelazadas por canales, instrumentos y medios de vinculación, que han sido identificados de acuerdo con la experiencia internacional y adaptados a la realidad peruana.
  • Publicación
    Control avanzado sobre un sistema de aireación durante el cultivo de langostinos (Litopenaeus vannamei), usando modelos matemáticos para la predicción de oxígeno disuelto en acuicultura
    (Universidad de Piura, 2017)
    Guevara Córdova, Carlos Humberto
    La investigación propone un nuevo tipo de control avanzado sobre los sistemas de aireación con la finalidad de mantener el nivel adecuado de oxígeno disuelto en los estanques de cultivo del langostino White Shrimp. Para este fin se implementó un sistema de mediciones y un sistema de control avanzado: NEPSAC, este algoritmo de control usa la información recolectada para poder minimizar el consumo energético de los motores eléctricos que usan los aireadores por medio del modelamiento teórico del estanque. La señal de control obtenida se valida observando la salida del sistema y el set point. En cuanto a Software se usan soluciones libres basadas en el sistema operativo Debian y especialmente ensayadas para microcomputadores.
  • Publicación
    Posture, blood velocity in common femoral vein, and prophylaxis of venous thromboembolism
    (The Lancet, 1995)
    Amalia Pesantes M.
    ;
    Bernabé-Ortiz A.
    ;
    Diez-Canseco F.
    ;
    Miranda J.J.
    ;
    Ponce-Lucero V.
    Might leg elevation and avoidance of poor postures provide better prophylaxis against venous thromboembolism than heparin or mechanical methods? 12 supine subjects tilted in 3° increments from 6° leg-down to 12° leg-up showed linear increase in mean peak blood velocity and reduction in calibre in the common femoral vein (colour-duplex ultrasound). Between horizontal and 6° leg-up, velocity was increased by 17% and diameter reduced by 14%. A ranking of mean peak velocities in six postures (sitting; standing; trunk raised 35° to legs which were first horizontal and then tilted up 6°; supine, first horizontal then 6° leg-up) showed significant increases in velocity between consecutive positions.
Más visto
  • Publicación
    Anisotropy and humidity effect on tensile properties and electrical volume resistivity of fused deposition modeled acrylonitrile butadiene styrene composites
    (Pontificia Universidad Católica del Perú, 2017)
    Adauto Ureta, Anaís Elena
    In the present thesis, the influence of anisotropy and humidity in the tensile properties and electrical volume resistivity of Acrylonitrile Butadiene Styrene/Carbon Nanotubes and Acrylonitrile Butadiene Styrene/Micro Carbon Fibers manufactured by Fused Deposition Modeling 3D printing was studied. To study the influence of the anisotropy three different layer printing orientations were compared (0°, 45° and 45°/-45°) in a layer height of 0.2 mm. It was concluded that the influence of anisotropy is important on Acrylonitrile Butadiene Styrene/Micro Carbon Fibers tensile behavior due to relation that exist between the performance/resistance and the alignment of the reinforcement. On the other hand, no significant influence was found on the Acrylonitrile Butadiene Styrene/Carbon Nanotubes. On the electrical volume resistivity, no significant variation was found on the Acrylonitrile Butadiene Styrene/Carbon Nanotubes by the anisotropy of the layers. Acrylonitrile Butadiene Styrene/Micro Carbon Fibers could not be essayed because of the high resistance of the composite.
  • Publicación
    Preparation and characterization of sputtered hydroxyapatite thin films
    (Pontificia Universidad Católica del Perú, 2018)
    Farfán Lira, José Enrique
    In this work, hydroxyapatite (HAp) thin films were fabricated using two different sputtering techniques: Radio frequency magnetron sputtering and ion beam sputtering. In the first case, the films were grown on Ti-6Al-4V substrates using a high-purity commercial HAp target, obtaining a thickness ~200 nm. For the second method, the film were grown on pure titanium substrates using a self-produced HAp target. This target was fabricated with powders (Ca/P = 1.628, sintered and crushed). Here, the thickness of the fabricated film was ~300 nm. The sintering tests for the target fabrication were carried out using two different heating regimens at a maximum temperature of 1200 °C (holding time of 2h and 4h) using various additives. As additives, water (H2O), polyvinyl alcohol (PVA) and polyethylene glycol (PEG) were used to improve the mechanical strength of the green discs. The as-deposited films were amorphous in both cases. Therefore, the films were annealed to increase the crystallinity. Annealing was performed in air for 2h at temperatures: 400, 600 and 800 °C for RF-magnetron sputter samples; 600 and 800 °C for ion beam sputter samples. The result of the films shows in both cases that the crystallinity of HAp was improved only for the annealed samples fabricated with ion beam sputtering at 800 °C. In both cases energy dispersive X-ray spectroscopy measurements show a decrease in Ca/P ratio with increasing the temperature. Hardness results revealed an increase in this with the increase in temperature possibly due to the formation of titanium oxide. The roughness for the fabricated films with the RFmagnetron sputtering increases till an annealing temperature of 600 °C and then decreases till 800 °C, while the roughness for the fabricated films with ion beam sputtering is higher in the as-deposited samples and then this is reduced by increasing the annealing temperature.
  • Publicación
    Identificación de modelos institucionales público-privado-academia para la mejora de la gestión de la CTI
    (Consejo Nacional de Ciencia, Tecnología e Innovación Tecnológica - Concytec, 2022-11)
    Delich, Valentina
    Aborda una exploración de un modelo de vinculación para el sector público que sea aplicable a los principales actores de las Universidades – Empresas – Gobierno (U-E-G). Los sistemas de innovación, modelos de vinculación, tipos de vinculación y el momento en el que nos encontramos como país, son palancas que favorecen el intercambio o todo lo contrario. Por lo que, se hizo un recorrido por la realidad de cada sector desde la mirada de la vinculación, es decir, se hace una referencia desde la universidad, la empresa y el gobierno, para luego analizar de modo bilateral: empresa – universidad, universidad – gobierno y empresa gobierno, terminando con la interacción tripartita universidad – empresa - gobierno. Todas las combinaciones entrelazadas por canales, instrumentos y medios de vinculación, que han sido identificados de acuerdo con la experiencia internacional y adaptados a la realidad peruana.
  • Publicación
    Control avanzado sobre un sistema de aireación durante el cultivo de langostinos (Litopenaeus vannamei), usando modelos matemáticos para la predicción de oxígeno disuelto en acuicultura
    (Universidad de Piura, 2017)
    Guevara Córdova, Carlos Humberto
    La investigación propone un nuevo tipo de control avanzado sobre los sistemas de aireación con la finalidad de mantener el nivel adecuado de oxígeno disuelto en los estanques de cultivo del langostino White Shrimp. Para este fin se implementó un sistema de mediciones y un sistema de control avanzado: NEPSAC, este algoritmo de control usa la información recolectada para poder minimizar el consumo energético de los motores eléctricos que usan los aireadores por medio del modelamiento teórico del estanque. La señal de control obtenida se valida observando la salida del sistema y el set point. En cuanto a Software se usan soluciones libres basadas en el sistema operativo Debian y especialmente ensayadas para microcomputadores.
  • Publicación
    Posture, blood velocity in common femoral vein, and prophylaxis of venous thromboembolism
    (The Lancet, 1995)
    Amalia Pesantes M.
    ;
    Bernabé-Ortiz A.
    ;
    Diez-Canseco F.
    ;
    Miranda J.J.
    ;
    Ponce-Lucero V.
    Might leg elevation and avoidance of poor postures provide better prophylaxis against venous thromboembolism than heparin or mechanical methods? 12 supine subjects tilted in 3° increments from 6° leg-down to 12° leg-up showed linear increase in mean peak blood velocity and reduction in calibre in the common femoral vein (colour-duplex ultrasound). Between horizontal and 6° leg-up, velocity was increased by 17% and diameter reduced by 14%. A ranking of mean peak velocities in six postures (sitting; standing; trunk raised 35° to legs which were first horizontal and then tilted up 6°; supine, first horizontal then 6° leg-up) showed significant increases in velocity between consecutive positions.