ABSTRACT
The rheological behavior of aqueous solutions of polyvinyl alcohol at 4, 6, 8 and 10% by weight has been studied and evaluated at temperatures of 20, 25, 30 and 35 °C, using five non-Newtonian fluid models independent of time: Ferrys, Robertson-Stiff, Williamson, Sisko, and Ellis de Haven. The classical method consists in carrying out regression analysis. Using a comparative procedure of determination coefficients and variances, the model that most appropriately adjusts the experimental data to said model is selected. From the statistical point of view, the Sisko and Robertson-Stiff models present better regression parameters; to better specify the choice of the respective rheological model, a new factor has been proposed in the literature, the viscosity factor (VF), which expresses the relationship between apparent and dynamic viscosity. The analysis of this factor for the five models confirms the greater stability of the Ellis de Haven model in terms of the coefficient of variation of the VF. The value of VF fluctuates between 1 and 2 for all ranges of temperature and concentration experienced for vinyl alcohol solutions. As a consequence of the above, for the choice of the non-Newtonian fluid model associated with the rheology of the aqueous solution of polyvinyl alcohol, it is necessary to analyze the statistical parameters and the VF factor simultaneously.
ABSTRACT
Introducción: La patente es un título de propiedad industrial otorgado por el Estado al inventor de un nuevo producto o tecnología, susceptible de ser comercializado para obtener ganancias de forma exclusiva a un plazo de tiempo determinado. Objetivo: Determinar el número de patentes otorgadas a las universidades peruanas en el campo biomédico de 2010 a 2020, en comparación con la producción de otros inventores. Material y método: Este estudio descriptivo, observacional, retrospectivo y transversal analizó 73 patentes provenientes de un universo de 759, obtenidas de la base de datos del Instituto Nacional de Defensa de la Competencia y de la Protección de la Propiedad Intelectual en el Perú, de 2010 a 2020. Para comparar el número de patentes otorgadas a las universidades respecto a otros inventores, se aplicó la prueba del Chi Cuadrado de Pearson con la corrección de continuidad de Yates. Resultados: En el Perú, durante 2010 a 2020 se han otorgado 759 patentes, de las cuales 73 pertenecen al campo biomédico (9,61 %), de los cuales las universidades han generado 24,66 %; es decir 2,47 % del total. Además, las universidades presentaron diferencias significativas de producción de patentes (p = 0,019) en comparación a otros autores. Conclusiones: En el campo biomédico, la producción de patentes en las universidades peruanas ha sido muy limitadas desde 2010 a 2020. Además, las universidades presentaron significativamente menor producción de patentes en comparación a otros inventores, observándose que desde 2016, no se les ha otorgado ninguna patente de invención en el campo biomédico.
Introduction: A patent is an industrial property title granted by the State to the inventor of a new product or technology, susceptible of being marketed for profit on an exclusive basis for a determined period of time. Objective: To determine the number of patents granted to Peruvian universities in the biomedical field from 2010 to 2020, in comparison with the production of other inventors. Material and Methods: This descriptive, observational, retrospective and cross-sectional study analyzed 73 patents from a universe of 759 patents obtained from the database of the National Institute for the Defense of Competition and Protection of Intellectual Property in Peru, from 2010 to 2020. To compare the number of patents granted to universities with respect to other inventors, Pearson's chi-square test with Yates' continuity correction was applied. Results: In Peru, during the years 2010 to 2020, 759 patents have been granted, of which 73 belong to the biomedical field (9.61 %), of which universities have generated 24.66 %, i.e. 2.47 % of the total. Furthermore, universities showed significant differences in patent production (p = 0.019) compared to other authors. Conclusions: In the biomedical field, patent production in Peruvian universities has been very limited from 2010 to 2020. In addition, universities presented significantly lower patent production compared to other inventors, noting that since 2016, they have not been granted any invention patents in the biomedical field.
