Obtención de las propiedades del concreto celular para su aplicación en el análisis sísmico de edificios de muros de ductilidad limitada

El objeto de estudio de la presente investigación es el concreto celular, el cual viene siendo cada vez más investigado a nivel nacional. Dadas las ventajas que otorga sus propiedades térmicas y acústicas se pretende dar como alternativa al concreto convencional usado en la construcción de edificios con Muros de Ductilidad Limitada. Para el desarrollo de la siguiente investigación primero se realizará un diseño de mezclas del concreto celular que cumpla los requerimientos necesarios señalados en las normas ACI 211 y ACI 253. La obtención de los valores de las propiedades mecánicas reales del concreto se obtuvo mediante ensayos de laboratorio, estos ensayos se realizarán cumpliendo los requerimientos de las siguientes normas: NTP 339.034 Resistencia a la compresión del concreto, f´c=15.27 Mpa - ASTM C469 Módulo de elasticidad del concreto, E =16834.7 Mpa - ASTM C469M-14 Coeficiente de Poisson, v = 0.2631 -AASHTO T-336 Obtención del coeficiente de expansión térmica del concreto CTE = 9.23 µ/ºC-NTP 339.078 Resistencia a la flexión del concreto, Mr = 3.088 Mpa Luego de la obtención de los resultados de los ensayos estos se usarán como datos de entrada para hacer el análisis sísmico de un edificio con muros de ductilidad limitada con el objetivo que cumpla los requerimientos de la norma sismo resistente peruana E-030 2018 la cual indica que las derivas máximas para edificios con muros de ductilidad limitada es 0.5%Tesi

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Export of fresh blueberries to EE.UU.

The present business plan analyzes the financial viability of developing a line of business for the export of fresh blueberries, recognizing an opportunity in the fact of the cultivation and marketing of fruit, with multiple benefits for the different actors in the exportation to a market of high demand. The largest importer of blueberries is US with a share greater than 50% of the total imports worldwide, which represents an amount above the 214,000.00 tons (ITC-Trade Map, presented in the publication of the DGPA-MINAGRI). Considering that in the U.S. there is a growing trend for both the production and import, the North American market becomes attractive to the leading exporters of blueberry. The blueberry belongs to the family of berries, and there are multiple species. The Blueberry has beneficial properties for human health, one of the main is the high content of antioxidants, which contributes to prolonging the life expectancy of human beings, in a context where the tendency to consume products that promote good health is increasingly adopted worldwide. For Peru, the destination of exports is concentrated mainly in the U.S., Holland (The Netherlands), the United Kingdom and China, being the main exporters “Camposol” and “Talsa”. It should be also mentioned that the export business has a steady season, which maintains peaks among the months of September and December. These attributes are encouraging the consumption of blueberries in the U.S., Europe and Asia; markets that demand products that contribute to improve the quality of life.Trabajo de investigaciónEl presente plan de negocio analiza la viabilidad financiera de desarrollar una línea de negocio para la exportación de arándanos frescos, ya que reconoce una oportunidad en el hecho del cultivo y la comercialización del fruto, con múltiples beneficios para los diversos actores en la exportación hacia un mercado de alta demanda. El mayor importador de arándanos es los EE.UU. con una participación superior al 50% de las importaciones totales a nivel mundial, siendo esto una cantidad por encima de las 214,000.00 toneladas (ITC-Trade Map, presentado en la publicación de la DGPA-MINAGRI); conociendo que se mantiene una tendencia creciente tanto para la producción como la importación en los EE.UU. hace atractivo a los principales exportadores del arándano el mercado norteamericano. El arándano pertenece a la familia de los berries, y existen múltiples especies, el arándano tiene propiedades beneficiosas para la salud humana, una de las principales es el alto contenido de antioxidantes, que contribuye a prolongar la esperanza de vida de los seres humanos, donde hoy en día la tendencia a consumir productos que favorecen la buena salud, cada vez es más adoptada a nivel mundial. Para Perú, el destino de las exportaciones está concentrada principalmente en EEUU, Holanda (Países Bajos), Reino Unido y China, donde los principales exportadores son, Camposol y Talsa; también se debe mencionar que el negocio de la exportación cumple una estacionalidad, que mantiene picos entre los meses de septiembre a diciembre. Estos atributos están incentivando el consumo de arándanos en EE.UU, Europa y Asia; mercados que demandan productos que contribuyan a mejorar la calidad de vida