Análisis de acciones del operador en un SBLOCA de 1”en el fondo de la Vasija en un Reactor tipo PWR

La simulación de accidentes de rotura pequeña en el fondo de la vasija se aparta del convencional análisis de LOCA de rama fría, el más limitante en los análisis deterministas La rotura de una de las penetraciones de instrumentación de la vasija ha sido desestimada históricamente en los análisis de licencia y en los Análisis Probabilistas de Seguridad y por ello, hay una falta evidente de literatura para dicho análisis. En el año 2003 durante una inspección, se detectó una considerable corrosión en el fondo de la vasija de South Texas Project Unit I NPP. La evolución en el tiempo de dicha corrosión habría derivado en una pequeña rotura en el fondo de la vasija si su detección no se hubiera producido a tiempo. La OECD/NEA consideró la importancia de simular dicha secuencia en la instalación experimental ROSA, la cual fue reproducida posteriormente por grupos de investigación internacionales con varios códigos de planta. En este caso el código utilizado para la simulación de las secuencias experimentales es TRACE. Tanto en el experimento como en la simulación se observaron las dificultades de reinundar la vasija al tener la rotura en el fondo de la misma, haciendo clave la gestión del accidente por parte del operador. Dadas las condiciones excesivamente conservadoras del test experimental, como el fallo de los dos trenes de inyección de alta presión durante todo el transitorio, en las aplicaciones de los experimentos con modelo de Almaraz NPP, se ha optado por reproducir dicho accidente con condiciones más realistas, verificando el impacto en los resultados de la disponibilidad de los trenes de inyección de alta presión o los tiempos de las acciones manuales del operador, como factores más limitantes y estableciendo el diámetro de rotura en 1

Análisis de Estimación Óptima del Accidente de Pérdida de Refrigerante por Rotura Pequeña de 1”en Cabeza de Vasija en un Reactor tipo PWR

En el año 2002 durante una inspección se localizó una importante corrosión en la cabeza de la vasija de Davis Besse NPP. Si no se hubiera producido esa detección temprana, la corrosión hubiera provocado una pequeña rotura en la cabeza de la vasija. La OECD/NEA consideró la importancia de simular esta secuencia en la instalación experimental ROSA, la cual fue reproducida posteriormente por grupos de investigación internacionales con varios códigos de planta. En este caso el código utilizado para la simulación de las secuencias experimentales es TRACE. Los resultados de este test experimental fueron muy analizados internacionalmente por la gran influencia que dos factores tenía sobre el resultado: las acciones del operador relativas a la despresurización y la detección del descubrimiento del núcleo por los termopares que se encuentran a su salida. El comienzo del inicio de la despresurización del secundario estaba basado en la determinación del descubrimiento del núcleo por la lectura de los temopares de salida del núcleo. En el experimento se registró un retraso importante en la determinación de ese descubrimiento, comenzando la despresurización excesivamente tarde y haciendo necesaria la desactivación de los calentadores que simulan el núcleo del reactor para evitar su daño. Dada las condiciones excesivamente conservadoras del test experimentale, como el fallo de los dos trenes de inyección de alta presión durante todo el transitorio, en las aplicaciones de los experimentos con modelo de Almaraz NPP, se ha optado por reproducir dicho accidente con condiciones más realistas, verificando el impacto en los resultados de la disponibilidad de los trenes de inyección de alta presión o los tiempos de las acciones manuales del operador, como factores más limitantes y estableciendo el diámetro de rotura en 1

Simulación del accidente de SGTR en un PWR-W con TRACE para distintas metodologías de análisis determinista de seguridad

A Steam Generator Tube Rupture (SGTR) in a Pressurized Water Reactor (PWR) can lead to an atmospheric release bypassing the containment via the secondary system and exiting though the Pressurized Operating Relief Valves of the affected Steam Generator. That is why SGTR historically have been treated in a special way in the different Deterministic Safety Analysis (DSA), focusing on the radioactive release more than the possibility of core damage, as it is done in the other Loss of Coolant Accidents(LOCAs)

Parámetros reproductivos de las hembras de la raya mariposa Gymnura micrura (Elasmobranchii) en el sur del Golfo de México

The butterfly ray Gymnura micrura is a relatively abundant batoid species in southern Gulf of Mexico, where is incidentally caught and commercialized for human consumption. In this region, however, there are no estimations of reproductive parameters needed to assess population dynamics and vulnerability to fishing pressure by means of ecological risk assessments. From the analysis of 142 females with a disc width (DW) range of 23-87 cm, it was estimated a DW at maturity (DW50%) of 56.8 cm. The female reproductive cycle is annual, and the ovulation and parturition occur from February to July. Gestation last 10-11 months, and is concurrent with the vitellogenesis. Fecundity resulted of 1-11 embryos (average = 4.3), and is directly proportional to maternal DW. The sex ratio of embryos was female biased (1.2 females per each male), however, the mean number of females and males were not statistically different. There are apparent differences in the DW at maturity and the reproductive cycle of females between the southern Gulf of Mexico and the coast of Brazil populations.La raya mariposa Gymnura micrura es relativamente abundante en el sur del Golfo de México, en donde es capturada incidentalmente y comercializada para consumo humano. En esta región, a la fecha no existen estimaciones de los parámetros reproductivos necesarios para conocer su dinámica poblacional y evaluar su vulnerabilidad a la presión de pesca por medio de evaluaciones de riesgo ecológico. Del análisis de 142 hembras con un intervalo de ancho de disco (AD) de 23-87 cm, se estimó una longitud de madurez (AD50%) de 56.8 cm. El ciclo reproductivo de las hembras es anual; la ovulación y el alumbramiento ocurren entre febrero y julio. La gestación tiene una duración de 10-11 meses y es concurrente con la vitelogénesis. La fecundidad fue de 1-11 embriones (promedio = 4.3) y es directamente proporcional al AD de las hembras. La proporción de sexos de los embriones fue de 1.2 hembras por cada macho, pero el número promedio de hembras y machos no fue estadísticamente diferente. El AD de madurez de las hembras y el ciclo reproductivo de G. micrura es aparentemente diferente entre la población del sur del Golfo de México y la de la costa de Brasil

Effect of yttria addition on the microstructure and mechanical behavior of ODS ferritic alloys processed by High Energy Milling and Spark Plasma Sintering

Oxide dispersion strengthened (ODS) ferritic alloys are structural materials used in nuclear fusion reactors, which exhibit enhanced mechanical properties, as well as corrosion and irradiation resistance. In the present work, ODS ferritic alloys with composition Fe-14Cr-1.5W-0.4Ti-(0, 0.4, 0.8) Y2O3 (in wt.%) were prepared employing high energy milling (HEM) followed by Spark Plasma Sintering (SPS). The particle size distribution (PSD) of the milled powders was characterized by laser diffraction. These powders and the sintered materials produced were characterized using X-ray diffraction (XRD), and scanning electron microscopy (SEM). The sintered materials were also characterized by dilatometry, diametral compression, Vickers microhardness, and corrosion rate tests. The largest Young’s modulus, microhardness, and dimensional shrinkage/expansion were obtained for the 0.8 wt.% Y2O3 alloy. However, this alloy was the least ductile. Furthermore, the 0.8 wt.% Y2O3 alloy was the one with the least dimensional change. According to the potentiodynamic polarization studies, it was found that the protective layer of Cr2O3 formed on the surface of the three alloys studied was less effective for the yttria-free alloy, since in this case the rupture of such protective layer occurred earlier than for the case of the yttria-containing alloys. Based on these results, it is suggested that the 0.8 wt.% Y2O3 alloy having fine microstructure could constitute a potential alternative as a structural material for Gen IV-type reactors

Sesiones de derechos humanos en Latinoamérica

252 páginas : tablas , gráficos ; 27 cm.El contenido de este libro es el resultado de la iniciativa de varios colegas de Latinoamérica, miembros de la Asociación de Participantes del Concurso Interamericano de Derechos Humanos; surge de la necesidad de fomentar espacios académicos que contribuyan a la educación en Derechos Humanos, que se presenta debido al confinamiento por la pandemia ocasionada por la COVID - 19. Ante ello, y con el claro compromiso y empoderamiento de emprender este proyecto, la Red Latinoamericana de Estudio e Investigación de los Derechos Humanos y Derecho Internacional Humanitario y su capítulo Ecuador, coadyuvaron en su realización

Monetary Policy Report - July de 2021

Macroeconomic summary The Colombian economy sustained numerous shocks in the second quarter, pri¬marily related to costs and supply. The majority of these shocks were unantic¬ipated or proved more persistent than expected, interrupting the recovery in economic activity observed at the beginning of the year and pushing overall inflation above the target. Core inflation (excluding food and regulated items) increased but remained low, in line with the technical staff’s expectations. A third wave of the pandemic, which became more severe and prolonged than the previous outbreak, began in early April. This had both a high cost in terms of human life and a negative impact on Colombia's economic recovery. Between May and mid-June roadblocks and other disruptions to public order had a sig¬nificant negative effect on economic activity and inflation. The combination and magnitude of these two shocks likely led to a decline in gross domestic product (GDP) compared to the first quarter. Roadblocks also led to a significant in¬crease in food prices. The accumulated effects of global disruptions to certain value chains and increased international freight transportation prices, which since the end of 2020 have restricted supply and increased costs, also affected Colombia’s economy. The factors described above, which primarily affected the consumer price index (CPI) for goods and foods, explain to a significant degree the technical staff’s forecast errors and the increase in overall inflation above the 3% target. By contrast, increases in core inflation and in prices for regulated items were in line with the technical staff’s expectations, and can be explained largely by the elimination of various price relief measures put in place last year. An increase in perceived sovereign risk and the upward pressures that this im¬plies on international financing costs and the exchange rate were further con¬siderations. Despite significant negative shocks, economic growth in the first half of the year (9.1%) is now expected to be significantly higher than projected in the April re¬port (7.1%), a sign of a more dynamic economy that could recover more quickly than previously forecast. Diverse economic activity figures have indicated high¬er-than-expected growth since the end of 2020. This suggests that the negative effects on output from recurring waves of COVID-19 have grown weaker and less long-lasting with subsequent outbreaks. Nevertheless, the third wave of the coro¬navirus, and to an even greater degree the previously mentioned roadblocks and disruptions to public order, likely led to a decline in GDP in the second quar¬ter compared to the first. Despite this, data from the monthly economic tracking indicator (ISE) for April and May surpassed expectations, and new sector-level measures of economic activity suggest that the negative impact of the pandemic on output continues to moderate, amid reduced restrictions on mobility and im¬provements in the pace of vaccination programs. Freight transportation registers (June) and unregulated energy demand (July), among other indicators, suggest a significant recovery following the roadblocks in May. Given the above, annual GDP growth in the second quarter is expected to have been around 17.3% (previously 15.8%), explained in large part by a low basis of comparison. The technical staff revised its growth projection for 2021 upward from 6% to 7.5%. This forecast, which comes with an unusually high degree of uncertain¬ty, assumes no additional disruptions to public order and that any new waves of COVID-19 will not have significant additional negative effects on economic activity. Recovery in international demand, price levels for some of Colombia’s export com¬modities, and remittances from workers abroad have all performed better than projected in the previous report. This dynamic is expected to continue to drive recovery in the national income over the rest of the year. Continued ample international liquidity, an acceleration in vacci¬nation programs, and low interest rates can also be ex¬pected to favor economic activity. Improved performance in the second quarter, which led to an upward growth revision for all components of spending, is expected to continue, with the economy returning to 2019 production levels at the end of 2021, earlier than estimated in the April report. This forecast continues to account for the short-term effects on aggregate demand of a tax reform package along the lines of what is currently being pro-posed by the national government. Given the above, the central forecast scenario in this report projects growth in 2021 of 7.5% and in 2022 of 3.1% (Graph 1.1). In this scenar¬io, economic activity would nonetheless remain below potential. The noted improvement in these projections comes with a high degree of uncertainty. Annual inflation increased more than expected in June (3.63%) as a result of changes in food prices, while growth in core inflation (1.87%) was similar to projections. The in¬creased CPI for foods would be expected to persist for the remainder of the year, contributing to inflation remaining above the target. Overall and core inflation would be ex¬pected to return to close to 3% at the end of 2022, amid a deceleration in growth in the CPI for foods and reduced ex¬cess productive capacity. Recent increases in international freight and agricultural goods prices, as well as the live¬stock cycle and increased meat exports, have exerted up¬ward pressure on food prices, primarily in processed foods (see Box 21). In addition to these persistent factors affecting prices, national roadblocks and related disruptions to pub¬lic order in several cities throughout May and parts of June were reflected in a significant restriction of supply and an unexpected annual increase in the CPI for foods (8.52%). Inflation in regulated items (5.93%) also accelerated, due to a low basis of comparison on gasoline prices and the par¬tial lapse of relief measures on utility rates that were put in place in 2020. Inflation excluding food and regulated items recovered in line with projections to 1.87%, due to the rein¬statement of indirect taxes on certain goods and services that had been temporarily eliminated in 2020, and to up¬ward pressures exerted by prices for foods away from home (FAH), among other factors. The increase in perishable foods prices is expected to be reversed over the course of the year, assuming an absence of additional, long-lasting blockades of national roads. Increased processed food pric¬es would be expected to persist and contribute to keeping inflation above the target at the end of the year. Inflation excluding foods and regulated items is expected to contin¬ue to exhibit an upward trend, as excesses in productive ca¬pacity continue to close, and register a temporary increase in March 2022 largely due to the reinstatement of the FAH consumption tax. Given the above, overall year-end infla¬tion is expected to be 4.1% in 2021 and 3.1% in 2022 (Graph 1.2), and core inflation is expected to be 2.6% in 2021 and 3.2% in 2022 (Graph 1.3). The technical staff has interpreted the overall behavior of prices in the CPI excluding food and regulated items, alongside continued unexpected increases in economic activity, as signs of more ample excess productive capaci¬ty in the economy. This would be expected to persist over the next two years, with the output gap closing at the end of that period. Increased economic growth suggests a less negative output gap than estimated last quarter. Nevertheless, the behavior of core inflation, especially in services, suggests that potential GDP has recovered to an unanticipated degree and that ample excess capacity con¬tinues, with a persistent effect on aggregate demand. La¬bor market observation supports this interpretation, with persistent high levels of unemployment and stagnation in the recovery of jobs lost as a result of the pandemic. Increased inflation can be explained largely by shocks re¬lated to costs and supply, and by the dissolution of some price relief measures put in place in 2020. The growth and inflation forecasts described above would be consistent with a less negative output gap closing more quickly across the forecast horizon compared to the projection from the April report. Nevertheless, uncertainty surrounding excess capacity is very high and constitutes a risk to the forecast (Graphic 1.4). The fiscal accounts outlook deteriorated, Standard and Poor’s Global Ratings (S&P) and Fitch Ratings (Fitch) down¬graded Colombia’s credit rating, roadblocks and disrup¬tions to public order affected output, and the country faced a third wave of COVID-19 that was more severe and prolonged than the previous outbreak. These factors were reflected in an increased risk premium and depreciation of the peso compared to the dollar. This occurred in a favor¬able context in regard to foreign income, as international prices for oil, coffee, and other Colombian export goods in¬creased. This contributed to a recovery in the terms of trade and in the national income and mitigated upward pres¬sures on the risk premium and the exchange rate. Expected oil prices in this report are USD 68 per barrel (previous¬ly USD 61/bl) for 2021 and USD 66/bl (previously USD 60/ bl) for 2022. This increased trajectory shows convergence to oil prices below recently observed levels, as a result of increased global supply that would more than offset increased demand. As a result, the recent price increase is expected to be temporary. International financial conditions are expected to become somewhat less fa¬vorable in the current macroeconomic context, despite the improvement in foreign income due to increased demand and some higher prices for oil and other export products. Growth in foreign demand was better than expected in the previous report, with projections for 2021 and 2022 increasing from 5.2% to 6.0% and from 3.4% to 3.5%, respectively. For the year to date, figures for economic activity suggest more dynamic foreign demand than previously expected. Output recovery has been faster in the United States and China than in Latin America, as economic reactivation in the latter has been limit¬ed by outbreaks of COVID-19, restricted vaccine supplies, and a lack of fiscal space to confront the pandemic, among other factors. The positive dynamic in foreign goods trade has come amid a deterioration in value chains and a significant increase in commodities and freight prices (see Box 3). Inflation in the United States has been unexpectedly high, with observed and expected values remaining above the target, while growth forecasts have been revised upward. As a result, the beginning of a normalization in monetary policy in the U.S. could come earlier than previously projected. This report estimates that the U.S. Federal Reserve’s first rate increase will come at the end of 2022 (before the first quarter of 2023). Colombia’s risk premium is projected to be higher than forecast in the April report, and is expected to remain on a growth trajectory given the country’s accumulation of public and external debt. This would be expected to contribute to an increase in international financing costs on the forecast horizon. An expansionary monetary policy stance continues to support favorable do¬mestic financing conditions. The interbank rate and the reference banking indi¬cator (IBR)remained consistent with the policy interest rate in the second quar¬ter. Average deposit and credit rates continued at historical lows, despite some observed increases at the end of June. The peso-denominated credit portfolio continued to decelerate in annual terms and, between March and June, growth in the household credit portfolio accelerated, primarily related to housing pur¬chases. Disbursements and recovery in the commercial credit portfolio were significant, returning to high levels observed one year ago, when businesses required significant levels of liquidity to confront the economic effects of the pandemic. Meanwhile, credit risk increased, liability provisions remained high, and some banks withdrew from the balance of their past-due portfolios. Nev¬ertheless, financial system earnings have recovered, and liquidity and solvency levels remain above regulatory minimums. Beginning with this report, a new methodology will be used to quantify and communicate the uncertainty surrounding central macroeconomic fore¬casts in the context of an active monetary policy. The new methodology, known as predictive densities (PD), will be explained in detail in Box 1. PD methodology provides probability distributions of the main forecast vari¬ables (e.g. growth, inflation) based on the balance of risks of key factors that, in the technical staff’s judgment, could affect the economy on the forecast horizon. These distributions reflect the result of possible shocks (to external variables, prices, and economic activity) that the economy could sustain and the transmission effects considering Colombia’s economic structure and anticipated monetary policy responses. As a result, PD allows for the quantification of uncertainty around the central forecast and of its bias. In this report, the PD exercise shows a downward bias for both economic growth and output gap, while the op¬posite is shown for headline inflation (Graphs 1.1, 1.2 and 1.3). The balance of risks indicates more complex mone¬tary policy dilemmas than previously expected. The most significant anticipated risk regarding external financing would be a return to less favorable conditions in a sce¬nario in which the U.S. Federal Reserve promptly raises interest rates. Such a decision could come as the result of current levels of economic growth and higher-than-ex¬pected employment generating significant inflationary pressures on that country. Uncertainty regarding Colom¬bia’s fiscal outlook and the subsequent effects on the risk premium and external financing costs represent addi¬tional considerations. The risks to economic growth are mainly downside risks, relating especially to the effects of political and fiscal uncertainty on consumption and investment decisions and the potential for additional waves of COVID-19 and the subsequent effects on eco-nomic activity. Inflation risks take into account the po¬tential for more persistent shocks associated with dis¬ruption to value chains, higher international commodity and food prices, and a slower-than-expected recovery in the national agricultural chain as a result of the recent roadblocks. These would represent upward risks primarily to food and goods prices. The main downside risk to the inflation forecast would come from an increase in rental housing prices below the central scenario projection. This would be explained by weak demand and increased sup¬ply in 2022 as a result of high observed housing sales this year. All told, the PD exercise reveals a downward bias for economic growth forecast, with 90% probability of growth between 6.1% and 9.1% for 2021 and between 0.5% and 4.1% in 2022. The output gap also exhibits a downward bias to the central forecast scenario, primarily in 2022. On the contrary, an upward bias is expected for headline inflation forecast, with 90% probability ranging between 3.7% and 4.9% in 2021 and between 2.2% and 4.7% in 2022. 1.2 Monetary policy decision In its meetings in June and July the BDBR left the bench¬mark interest rate unchanged at 1.75% (Graph 1.5).Box 1. Characterizing and Communicating the Balance of Risks of Macroeconomic Forecasts: A Predictive Densities Approach for Colombia Authors: Juan Camilo Méndez-Vizcaíno, César Ánzola-Bravo, Alexander Guarín y Anderson Grajales-OlarteBox 2. Analysis of Recent Disturbances in Global Logistics Chains and their Impact on Colombian Import Markets. Authors: Aarón Garavito, Juan Diego Cortés, Stefany Andrea Moreno, Alex Fernando Pérez y Juan Esteban CarranzaBox 3. The Upward Dynamics of Food Prices. Authors: Edgar Caicedo G., Andrea Salazar D. y Jesús Daniel Sarmiento S

Planeación, gobernanza y sustentabilidad Retos y desafíos desde el enfoque territorial

Frente a la compleja realidad actual, resulta ineludible el desarrollo de la investigación científica de los fenómenos y procesos urbanos, territoriales y ambientales, que contribuya a su comprensión y la construcción de alternativas de solución a los retos y desafíos vigentes. En este contexto, el abordaje de las ciudades y regiones metropolitanas, el ordenamiento del territorio y la ocupación del espacio, así como la relación sociedad-naturaleza y la complejidad ambiental, precisa la generación de metodologías y procesos de investigación multi e inter disciplinarios que contribuyan a la comprensión de los procesos socioterritoriales, el mejoramiento de las condiciones de vida y la conservación ambiental.Programa de Fortalecimiento de la Calidad Educativa PFCE-2016 proyecto K0313101

5to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

El V Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2019, realizado del 6 al 8 de febrero de 2019 y organizado por la Universidad Politécnica Salesiana, ofreció a la comunidad académica nacional e internacional una plataforma de comunicación unificada, dirigida a cubrir los problemas teóricos y prácticos de mayor impacto en la sociedad moderna desde la ingeniería. En esta edición, dedicada a los 25 años de vida de la UPS, los ejes temáticos estuvieron relacionados con la aplicación de la ciencia, el desarrollo tecnológico y la innovación en cinco pilares fundamentales de nuestra sociedad: la industria, la movilidad, la sostenibilidad ambiental, la información y las telecomunicaciones. El comité científico estuvo conformado formado por 48 investigadores procedentes de diez países: España, Reino Unido, Italia, Bélgica, México, Venezuela, Colombia, Brasil, Estados Unidos y Ecuador. Fueron recibidas un centenar de contribuciones, de las cuales 39 fueron aprobadas en forma de ponencias y 15 en formato poster. Estas contribuciones fueron presentadas de forma oral ante toda la comunidad académica que se dio cita en el Congreso, quienes desde el aula magna, el auditorio y la sala de usos múltiples de la Universidad Politécnica Salesiana, cumplieron respetuosamente la responsabilidad de representar a toda la sociedad en la revisión, aceptación y validación del conocimiento nuevo que fue presentado en cada exposición por los investigadores. Paralelo a las sesiones técnicas, el Congreso contó con espacios de presentación de posters científicos y cinco workshops en temáticas de vanguardia que cautivaron la atención de nuestros docentes y estudiantes. También en el marco del evento se impartieron un total de ocho conferencias magistrales en temas tan actuales como la gestión del conocimiento en la universidad-ecosistema, los retos y oportunidades de la industria 4.0, los avances de la investigación básica y aplicada en mecatrónica para el estudio de robots de nueva generación, la optimización en ingeniería con técnicas multi-objetivo, el desarrollo de las redes avanzadas en Latinoamérica y los mundos, la contaminación del aire debido al tránsito vehicular, el radón y los riesgos que representa este gas radiactivo para la salud humana, entre otros