Eigenvalue estimates for submanifolds of warped product spaces

We give lower bounds for the fundamental tone of open sets in minimal submanifolds immersed into warped product spaces of type $N^n \times_f Q^q$, where $f \in C^\infty(N)$. We also study the essential spectrum of these minimal submanifolds.Comment: 17 page

Obtaining Au thin films in atmosphere of reactive nitrogen through magnetron sputtering

4d and 5d series of the transition metals are used to the obtaining nitrides metallic, due to the synthesis of PtN, AgN and AuN in the last years. Different nitrides are obtained in the Plasma Assisted Physics Vapour Deposition system, due to its ionization energy which is necessary for their formation. In this paper a Magnetron Sputtering system was used to obtain Au thin films on Si wafers in Nitrogen atmosphere. The substrate temperature was varied between 500 to 950°C. The samples obtained at high temperatures (>500°C) show Au, Si and N elements, as it is corroborated in the narrow spectrum obtained for X-Ray Photoelectron Spectroscopy; besides the competition of orientation crystallographic texture between (111) and (311) directions was present in the X-Ray Diffraction analysis to the sample heated at 950°C

II Workshop on Modeling and Simulation for Science and Engineering

II Workshop on Modeling and Simulation for Science and Engineering (II WMSSE) was a conference conducted at Universidad Tecnológica de Bolívar, in the city of Cartagena de Indias, Colombia, on September 24, 25 and 26, 2019. There, works in several topics of science, technology and engineering were presented. Specially, the participants of conference wanted to bring some solutions to the actual industrial requirements such as improvement and optimization of the heat transfer equipment, electronic devices, system control by mean of computational modeling. Also, dynamic system control was widely used for the prediction of power flow market, diffusion of bacteria in coffee production, stress concentration in industrial machines, analysis of population dynamics, model of hydrological and pluviometric networks, encryption for intercommunication of substation control centers, and others

Tecnologías poscosecha con cultivos biofortificados

La bioforti¬cación es una estrategia que utiliza el ¬tomejoramiento convencional de cultivos básicos para incrementar el contenido de nutrientes y mejorar sus características agronómicas. Es un complemento importante de otras intervenciones como la suplementación con micronutrientes y la forti¬cación de alimentos para mejorar la situación nutricional de la población. Una de las iniciativas para llegar con los cultivos bioforticados a las poblaciones más necesitadas es producir alimentos procesados industrialmente, que utilicen los cultivos bioforti¬cados como la materia prima, pero que sean elaborados con tecnologías de procesamiento que no eliminen sus ventajas de mayor densidad nutricional. En otras palabras, con el procesamiento de los cultivos bioforti¬cados se pueden obtener productos alimenticios de alto valor nutritivo, con los que sea más fácil lograr un consumo masivo y tener un mayor impacto con la estrategia de biofortificación

La pandemia de gripe de 1918–1919 en Bogotá y Boyacá, 91 años después

ResumenIntroducciónLa pandemia de gripa de 1918–1919 causó la mayor mortalidad en la historia en corto tiempo. Se estima que entre 20 millones y 50 millones de personas fallecieron en menos de un año. Los historiadores de Europa y Estados Unidos registran tres oleadas, con mayor impacto en octubre y noviembre (80% de la mortalidad), que afectaron la población económicamente activa. La gripa nos ha acompañado en América desde el segundo viaje de Colón, probablemente asociada a la importación de cerdos y caballos infectados.Materiales y métodosSe describen las condiciones sociales y de salud en Bogotá y Boyacá, a partir de fuentes documentales de la época. Las tasas de mortalidad se calcularon a partir de los registros de la Iglesia.ResultadosLas condiciones de pobreza y hacinamiento acentuaron la letalidad. La iniciativa privada asumió el control y la atención de las víctimas, dada la ineficiencia de las auautoridades. Se recolectaron 106.484 registros de defunción del periodo 1912–1927, 9,5% (10.123 muertes) por gripa. Entre octubre y noviembre de 1918, hubo 2.019 muertes en Boyacá, con una tasa de 4,8 por 1.000 habitantes, y predominio en menores de 5 años y en ancianos; no se observaron oleadas. La mayor altura sobre el nivel del mar resultó ser un factor de riesgo para la muerte por gripa.DiscusiónLas condiciones actuales favorecen una nueva pandemia. Los nuevos medios de transporte podrían aumentar la velocidad de transmisión de la infección. Se hace necesario conocer el pasado y las implicaciones en la mortalidad para evitar repetir los errores en el futuro.AbstractIntroductionThe pandemic Flu of 1918–19 was the cause of the greatest mortality in history, in a very short period of time. An estimated mortality between 20 and 50 million deaths/year was calculated. The European and American researchers registered three different epidemic peaks, with a special impact between October and November (80% mortality), affecting a large proportion of the economically active population. Since Colombo's second travel, the Flu has been within us, probably associated with the presence infected pigs and horses, brought by the Spaniards.Materials and methodsWe describe the social and health conditions in Bogotá and Boyacá, from documentary sources of the time. Mortality rates were estimated from Church records.ResultsPoverty and overcrowding conditions increased the epidemic lethality. As a result of the inefficiency of the authorities of that time, the control and care of victims were assumed by private organizations. We collected 106,484 records from death certificates, since 1912 until 1927; 9.5% (10,123 deaths) were caused by flu. The mortality rate attributed to the Flu was 4.8 per 1,000 people (2,019 deaths) between October and November of 1918. Children under 5 years and the elder people were mainly affected by Flu. The highest altitude above sea level was a risk factor for Flu mortality and non epidemic waves were observed.DiscussionDue to current general conditions, a new epidemic is possible. New means of transportation may increase its transmission rate. Lessons from the past can lead us to avoid repeating same mistakes in the future