Failure detection in a pressure vessel using acoustic emissions technology

The acoustic emission (AE) technique was implemented to monitor different failure stages in steel cylinders used to store Liquefied Petroleum Gas (LPG). Experiments in two containers with external and internal defects subjected to a hydrostatic test were carried out. The severity of the faults was progressively increasing through the different stages to study the microseismic activity. The experimental tests allowed checking the Kaiser and Felicity effects. Additionally, it was observed that an increase in the severity of the failure depicts an increase in the number of hits, counts and energy values detected. The evolution of the acoustic activity for the different failure stages established the container's structural integrity, proving that AE allows evaluating its entire condition.En este artículo se implementó la técnica de emisiones acústicas (EA) para monitorear diferentes escenarios de falla en cilindros de acero usados para almacenar gas licuado del petróleo (GLP). Los experimentos se llevaron a cabo en dos recipientes con defectos externos e internos sometidos a una prueba hidrostática. La severidad de las fallas fue aumentando progresivamente a través de los distintos escenarios con el fin de estudiar la actividad microsísmica. Las pruebas experimentales permitieron comprobar los efectos Káiser - Felicity y se observó que un aumento en la severidad de la falla representaba un incremento en la cantidad de hits detectados, cuentas y valores de energía. La evolución de la actividad acústica para los diferentes escenarios de falla determinó la integridad estructural de los contenedores, demostrándose que las EA permiten evaluar la condición global de los cilindros

Dinámica de sistemas para la selección de un sistema de pronóstico con base en el impacto de excesos y faltantes

This article studies the effect of the excesses and shortages in an organization, specifically in a product whose demand is growing. A system dynamics model was made through two diagrams two diagrams that are joined and related. In one of the diagrams is easy a sharing of forecast data, and in the main plot we can see the relations in the selection of a forecast with other components that are part of the organization. Based on all the relationships, we concluded about the impact of using three types of forecasts on finished goods inventory, safety stock, the level of service and the marginal utility of an organization.En el presente artículo se estudia el efecto de los excesos y faltantes en una organización, específicamente en un producto cuya demanda es creciente. Para facilitar el análisis, se realizó un modelo de dinámica de sistemas, compuesto de dos diagramas que posteriormente se relacionan. En uno de los diagramas se pueden intercambiar datos de los pronósticos, y en el diagrama principal se pueden observar las relaciones que tiene la selección de dicho pronóstico con otros aspectos que hacen parte de la organización. Su finalidad es conocer el impacto que genera el uso de tres tipos de pronósticos sobre el inventario de producto terminado, el inventario de seguridad, el nivel de servicio y la utilidad marginal de una organización

A genetic modifier screen identifies chromosomal intervals harboring potential midline interacting genes

This work investigates the growth of B-C-N layers by chemical vapor deposition using methylamine borane (MeAB) as single-source precursor. MeAB has been synthesized and characterized, paying particular attention to the analysis of its thermolysis products, which are the gaseous precursors for B-C-N growth. Samples have been grown on Cu foils and transferred onto different substrates for their morphological, structural, chemical, electronic and optical characterizations. The results of these characterizations indicate a segregation of h-BN and Graphene-like (Gr) domains. However, there is an important presence of B and N interactions with C at the Gr borders, and of C interacting at the h-BN-edges, respectively, in the obtained nano-layers. In particular, there is significant presence of C-N bonds, at Gr/h-BN borders and in the form of N doping of Gr domains. The overall B:C:N contents in the layers is close to 1:3:1.5. A careful analysis of the optical bandgap determination of the obtained B-C-N layers is presented, discussed and compared with previous seminal works with samples of similar composition.Comment: 35 pages, 7 figure

Chemical vapor deposition growth of boron-carbon-nitrogen layers from methylamine borane thermolysis products

This is the Accepted Manuscript version of an article accepted for publication in Nanotechnology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1361-6528/aa9c07This work investigates the growth of B-C-N layers by chemical vapor deposition using methylamine borane (MeAB) as the single-source precursor. MeAB has been synthesized and characterized, paying particular attention to the analysis of its thermolysis products, which are the gaseous precursors for B-C-N growth. Samples have been grown on Cu foils and transferred onto different substrates for their morphological, structural, chemical, electronic and optical characterizations. The results of these characterizations indicate a segregation of h-BN and graphene-like (Gr) domains. However, there is an important presence of B and N interactions with C at the Gr borders, and of C interacting at the h-BN-edges, respectively, in the obtained nano-layers. In particular, there is a significant presence of C-N bonds, at Gr/h-BN borders and in the form of N doping of Gr domains. The overall B:C:N contents in the layers is close to 1:3:1.5. A careful analysis of the optical bandgap determination of the obtained B-C-N layers is presented, discussed and compared with previous seminal works with samples of similar compositio

Tifus murino en el cairo-valle ¿brote o condición endémica emergente?

En el Municipio de El Cairo Valle se reportó un brote de Tifus Murino, el cual habitualmente no se diagnostica en la región. Se presenta una serie de casos obtenidos del Sistema de Vigilancia Epidemiológica del Municipio de El Cairo, administrado por el Hospital Municipal

Publisher Correction: Toxoplasma Modulates Signature Pathways of Human Epilepsy, Neurodegeneration & Cancer.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper

Colombian consensus recommendations for diagnosis, management and treatment of the infection by SARS-COV-2/ COVID-19 in health care facilities - Recommendations from expert´s group based and informed on evidence

La Asociación Colombiana de Infectología (ACIN) y el Instituto de Evaluación de Nuevas Tecnologías de la Salud (IETS) conformó un grupo de trabajo para desarrollar recomendaciones informadas y basadas en evidencia, por consenso de expertos para la atención, diagnóstico y manejo de casos de Covid 19. Estas guías son dirigidas al personal de salud y buscar dar recomendaciones en los ámbitos de la atención en salud de los casos de Covid-19, en el contexto nacional de Colombia

Failure detection in a pressure vessel using acoustic emissions technology

The acoustic emission (AE) technique was implemented to monitor different failure stages in steel cylinders used to store Liquefied Petroleum Gas (LPG). Experiments in two containers with external and internal defects subjected to a hydrostatic test were carried out. The severity of the faults was progressively increasing through the different stages to study the microseismic activity. The experimental tests allowed checking the Kaiser and Felicity effects. Additionally, it was observed that an increase in the severity of the failure depicts an increase in the number of hits, counts and energy values detected. The evolution of the acoustic activity for the different failure stages established the container's structural integrity, proving that AE allows evaluating its entire condition.En este artículo se implementó la técnica de emisiones acústicas (EA) para monitorear diferentes escenarios de falla en cilindros de acero usados para almacenar gas licuado del petróleo (GLP). Los experimentos se llevaron a cabo en dos recipientes con defectos externos e internos sometidos a una prueba hidrostática. La severidad de las fallas fue aumentando progresivamente a través de los distintos escenarios con el fin de estudiar la actividad microsísmica. Las pruebas experimentales permitieron comprobar los efectos Káiser - Felicity y se observó que un aumento en la severidad de la falla representaba un incremento en la cantidad de hits detectados, cuentas y valores de energía. La evolución de la actividad acústica para los diferentes escenarios de falla determinó la integridad estructural de los contenedores, demostrándose que las EA permiten evaluar la condición global de los cilindros

Yb(OTf)3-Catalyzed Bromination Reactions of Natural Product-like N-Benzyl Cinnamamides: A Facile Route to Diverse N-Substituted Amides of Pharmacological Interest

Diverse natural product-like N-benzyl cinnamamides were prepared by condensation of trans-cinnamic acid with substituted benzylamines in the presence of boric acid as catalyst. The further evaluation of this amides as a substrates of the bromo-arylation reaction, in the presence of N-bromosuccinimide (NBS) as the halogen source and under the catalysis of Yb(OTf)3, generate a different types of N-substituted amides: N-aryl 2,3-dibromopropanamides, N-(2-bromobenzyl) cinnamamides and tetrahydro-2-benzazepin-3-one as a new molecules. Here we discuss the formation of these main products on the basis of the electronic nature of the substituents present in the N-benzyl aromatic ring of the prepared cinnamamides.Departamento Administrativo de Ciencia, Tecnología e Innovación [CO] Colciencias5507-543-31904Programa: Bioprospección y desarrollo de ingredientes naturales para las industrias cosmética, farmacéutica y de productos de aseo con base en la biodiversidad colombianan

Structural modeling and ground motion selection for risk assessment of pre-Northridge welded steel moment frames

Nonlinear response history analyses are the most reliable tool for quantifying the earthquake performance of structures and inform risk management decisions like acquiring insurance or planning a structural retrofit. Constructing these models requires assumptions about the structure and its earthquake hazard that are normally made based on a limited number of analyses or expert opinions. This paper summarizes a sensitivity study that systematically evaluates the effects of the most common assumptions for modeling pre-Northridge welded steel moment frames (WSMF) on robust risk metrics. These assumptions include choosing a connection modeling approach and defining the target parameters for ground motion selection and scaling. The results of this sensitivity study support practical recommendations for applying the full performance-based earthquake engineering framework as implemented in FEMA P58 to tall WSMF buildings.Applied Science, Faculty ofNon UBCCivil Engineering, Department ofUnreviewedFacultyResearcherGraduat