Análisis de sobretensiones transitorias en redes de baja tensión

Sensitivity analysis of a power system against overvoltage was performed. The analysis took into account the origin of the overvoltage, the grounding resistance magnitude and overvoltage injection point. The IEEE 13 bus test feeder system was implemented in EMTP-ATP and lightning and switching overvoltages were applied. Three cases were evaluated: the first one, applying lightning overvoltage and varying the grounding resistance magnitude; the second, applying lightning overvoltage in different points of the system with a fixed grounding resistance magnitude; and finally, applying switching overvoltage and varying the grounding resistance magnitude.Se realizó un análisis de sensibilidad de un sistema de potencia contra sobretensión. El análisis tuvo en cuenta el origen de la sobretensión, la magnitud de la resistencia de puesta a tierra y el punto de inyección de sobretensión. El sistema de alimentación de prueba de bus IEEE 13 se implementó en EMTP-ATP y se aplicaron sobretensiones de sobretensión y de sobretensión. Se evaluaron tres casos: el primero, aplicando sobretensión de rayo y variando la magnitud de la resistencia a tierra; el segundo, aplicar sobretensión de rayo en diferentes puntos del sistema con una magnitud de resistencia a tierra fija; y finalmente, aplicar sobretensión de conmutación y variar la magnitud de la resistencia de puesta a tierra

Optimization of resources for digital radio transmission over IBOC FM through max-min fairness

The equitable distribution of resources in a network is a complex process, considering that not all nodes have the same requirements, and the In-Band On-Channel (IBOC) hybrid transmission system is no exception. The IBOC system utilizes a hybrid in-band transmission to simultaneously broadcast analog and digital audio over the FM band. This article proposes the use of a Max-Min Fairness (MMF) algorithm, with a strategy to optimize resource allocation for IBOC FM transmission in a multiservice scenario. Additionally, the MMF algorithm offers low computational complexity for implementation in low-cost embedded systems, aiming to achieve fair resource distribution and provide adequate Quality of Service (QoS) levels for each node in the RF network, considering channel conditions and traffic types. The article explores a scenario under saturated traffic conditions to assess the optimization capabilities of the MMF algorithm under well-defined traffic and channel conditions. The evaluation process yielded highly favorable results, indicating that theMMF algorithm can be considered a viable alternative for bandwidth optimization in digital broadcasting over IBOC on FM with 95% confidence, and it holds potential for implementation in other digital broadcasting system.Comment: 10 pages, 3 tabl

Mineralogy and fluid-inclusion microthermometry of the vein with Au-Ag ore of La Aurora mine in the northern part of the Zaragoza–Segovia–Remedios mining district (ZSRMD), Colombia

La veta de la mina La Aurora con mineralización aurífera asociada, hace parte del Distrito Minero Zaragoza–Segovia–Remedios (DMZSR), localizado en el flanco oriental de la Cordillera Central de los Andes colombianos. Dicha mineralización está emplazada en rocas metamórficas del Complejo Cajamarca, y corresponde a una veta de cuarzo con una secuencia paragenética que define tres eventos mineralizantes: i) Etapa I con asociación mineral Qz+Py+Ccp+Po, ii) Etapa II con paragénesis entre Qz+Chl+Ser+Cal+Py+Ccp+Gn+Au+Sp+Ant y iii) Etapa III con asociación entre Qz+Ser+Cal+Py+Ccp+Gn+Au+Rt+Sp+Gth+Mrc. Los fluidos mineralizantes con formación de oro (etapas II y III) son de baja salinidad y temperaturas que varían entre 165,8°C y 262,9°C. La veta contiene dos tipos de inclusiones fluidas primarias bifásicas (LV) en cuarzo de Etapa II y un tipo de inclusiones fluidas secundarias: Tipo IL con temperatura de homogenización (Th) que varía entre 165,8°C y 195°C y salinidad entre 4,3 y 5,9 wt % NaCl eq.; Tipo IIL con temperatura de homogenización (Th) que varía entre 200°C y 262,9°C y salinidad entre 5,9 y 11,6 wt % NaCl eq.; Tipo V son inclusiones monofásicas con tamaños menores a 5 μ. Las relaciones de oro y plata con otros metales son variables, presentando valores promedio de Au/Ag=1,24, Au/Bi=1,02, Au/Pb=0,01, Au/Zn=0,02, Ag/Bi=0,75, Ag/Pb=0,01 y Ag/Zn=0,03. Las propiedades físicas y químicas calculadas con los datos medidos de las inclusiones fluidas relacionadas con la secuencia paragenética y los análisis geoquímicos, permiten plantear que las condiciones de formación de las mineralizaciones de oro se dieron en niveles corticales someros, posiblemente en un sistema epitermal. El Sistema de Fallas Otú–Pericos controló el emplazamiento y la distribución espacial de la veta mineralizada.The gold mineralization related to the vein of La Aurora mine is part of the Zaragoza–Segovia–Remedios Mining District (ZSRMD), located in the eastern flank of Central Cordillera of Colombia. This mineralization is emplaced in metamorphic rocks from Cajamarca Complex and corresponds to a quartz vein with a paragenetic sequence that defines three mineralizing events: i) Stage I with mineral associations Qz+Py+Ccp+Po, ii) Stage II with paragenesis among minerals such as Qz+Chl+Ser+Cal+Py+Ccp+Gn+Au+Sp+Ant and iii) Stage III with associations among minerals Qz+Ser+Cal+Py+Ccp+Gn+Au+Rt+Sp+Gth+Mrc. Mineralizing fluids with the gold formation (stages II and III) are of low salinity and the temperatures between 165.8°C and 262.9°C. The vein contains two types of biphasic primary fluid inclusions (LV) in quartz of the stage II and one type of secondary fluid inclusions: Type IL with a homogenization temperature (Th) between 165.8°C to 195°C and salinity between 4.3 to 5.9 wt % NaCl eq.; Type IIL with homogenization temperature (Th) between 200°C to 262.9°C and salinity between 5.9 to 11.6 wt % NaCl eq.; Type V are monophase inclusions with sizes smaller than 5 μ. The ratios between gold/silver and other metals are variable, with average values of Au/Ag=1.24, Au/Bi=1.02, Au/Pb=0.01, Au/Zn=0.02, Ag/Bi=0.75, Ag/Pb=0.01 and Ag/Zn=0.03. Physical and chemical properties calculated with the measured data from fluid inclusions and related to the paragenetic sequence, and geochemical analysis suggest that the formation conditions of gold mineralization occurred in shallow crustal levels, possibly in an epithermal system. The Otú–Pericos Fault System possibly controlled the emplacement and spatial distribution of the mineralized vein

Reflexiones alrededor de la Iglesia y la Educación en el contexto latinoamericano

Fil: Pérez Vargas, John Jairo. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Pinto López, Carlos Andrés. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Nieto Bravo, Johan Andrés. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Santamaría Rodríguez, Juan Esteban. Universidad Católica de Córdoba. Facultad de Educación; Argentin

Cutaneous manifestations of early systemic lupus erythematosus and correlation with systemic activity

RESUMEN: Las manifestaciones cutáneas del lupus eritematoso sistémico (LES) son heterogéneas (específicas e inespecíficas). Poco se sabe acerca de la relación entre estas manifestaciones y la actividad clínica e inmunológica de la enfermedad en sus etapas iniciales. Se llevó a cabo un estudio de corte transversal en 34 pacientes con LES temprano. Se encontró una asociación significativa entre alopecia e hipocomplementemia C3 (p = 0,021), hipocomplementemia C4 (p < 0,001) y anti-Sm (p = 0,011); entre eritema malar y anti-Ro (p = 0,037) y anti-La (p = 0,037); entre fotosensibilidad y anti-RNP (p = 0,037). Se observó una tendencia a la asociación entre úlceras orales e hipocomplementemia C4 (p = 0,064). No hubo asociación entre las manifestaciones cutáneas y la presencia de anti-ADN de doble cadena (anti-ds ADN), anticuerpos anticardiolipinas, anticoagulante lúpico, VDRL falso positivo, leucopenia, trombocitopenia, hipergammaglobulinemia, elevación de la velocidad de sedimentación globular o SLEDAI. Se resalta la importancia de la relación entre las manifestaciones cutáneas inespecíficas de LES (alopecia y fotosensibilidad) y la actividad sistémica en pacientes con enfermedad temprana y la clara asociación de estas con hipocomplementemia, un marcador importante de actividad inmunológica.ABSTRACT: Cutaneous manifestations of systemic lupus erythematosus (SLE) are heterogeneous (both specific and non-specific). Little is known about the relationship between these manifestations and the clinical and immunological activity of the disease in early stages. We carried out a cross-sectional study in 34 patients with early SLE. We found a significant association between alopecia and hypocomplementemia C3 (p = 0.021), hypocomplementemia C4 (p < 0.001) and anti-Sm (p = 0.011); between malar erythema and anti-Ro (p = 0.037) and anti-La (p = 0.037); between photosensitivity and anti-RNP (p = 0.037). We observed a trend to association between oral ulcers and hypocomplementemia C4 (p = 0.064). No association was found between cutaneous manifestations and the presence of anti-ds DNA, anticardiolipin antibodies, lupus anticoagulant, false-positive VDRL, leucopenia, thrombocytopenia, hypergammaglobulinemia, elevated erythrosedimentation rate or SLEDAI. We highlight the relevance of the relationship between non-specific cutaneous manifestations of early SLE (alopecia and photosensitivity) and the systemic activity of the disease and hypocomplementemia, an important marker of immunological activity

Comportamiento agroindustrial de seis variedades de Caña de azúcar (Saccharum spp.) para Panela en Barbosa (Colombia)

In Colombia, sugarcane production is the second most important line of agricultural production after coffee, 55% of the total cultivated area is dedicated to the production of panela (non-centrifuged sugar - NCS), a task that is carried out in 29 of the 32 departments of the country. Low yields and the loss of genetic quality of the materials currently being cultivated have brought about the need to evaluate new varieties of sugarcane that adapt to different environments and have a high production of panela. Considering the above, between November 2018 and May 2020, by the Colombian Agricultural Research Corporation - Agrosavia, under the agroecological conditions of Barbosa (Santander, Colombia), the agroindustrial behavior of six sugarcane varieties for panela production (CC 11-600, CC 10-450, CC 99-2461, CC 00-3257, CC 91-1606 and CC 00-3771) from the Colombian sugarcane research center - Cenicaña were evaluated; A randomized complete block design was established with four repetitions for agronomic performance and three replicates for industrial evaluation. Agronomically, the genetic materials presented averages of 2.81 m to plant height, 2.8 cm stem diameter, percentage of Diatraea infestation intensity of 10.66% and 118.92 tons of cane per hectare; for the industrial variables, average values of 21.06 °Brix in juice and 12.78 tons of panela per hectare were found; the evaluated variables referring to panela quality were adjusted to those required in the NTC 1311: 2009 and Resolution 000779 of 2006 of the Ministry of Social Protection. Varieties CC 11-600 and CC 00-3267 showed the best agroindustrial performance in the first production cycle.En Colombia, la producción de caña de azúcar es el segundo renglón más importante en la producción agrícola después del café, 55 % del total del área cultivada se dedica a la producción de panela (Azúcar no centrifugado-NCS, por sus siglas en inglés) labor que se realiza en 29 de los 32 departamentos del país. Los bajos rendimientos y la pérdida de calidad genética de los materiales que actualmente se cultivan ha traído consigo la necesidad de evaluar nuevas variedades de caña de azúcar que se adapten a diversos ambientes y que cuenten con una alta producción de panela. Teniendo en cuenta lo anterior, entre noviembre de 2018 y mayo de 2020, por parte de la Corporación Colombiana de Investigación Agropecuaria – Agrosavia, bajo las condiciones agroecológicas de Barbosa (Santander, Colombia), se evaluó el comportamiento agroindustrial de seis variedades de caña de azúcar para producción de panela (CC 11-600, CC 10-450, CC 99-2461, CC 00-3257, CC 91-1606 y CC 00-3771) provenientes del centro de investigación de la caña de azúcar de Colombia – Cenicaña; se estableció un diseño de bloques completos al azar con cuatro repeticiones para el comportamiento agronómico y tres repeticiones para la evaluación industrial. En lo agronómico, los materiales genéticos presentaron promedios de 2,81 m para altura de tallo a punto de quiebre, 2,8 cm de diámetro de tallo, porcentaje de intensidad de infestación de Diatraea del 10,66% y 118,92 toneladas de caña por hectárea; para las variables industriales, sen encontraron valores promedio de 21,06 °Brix en jugo y 12,78 toneladas de panela por hectárea, las variables evaluadas referentes a calidad de panela se ajustaron a las requeridas en las NTC 1311:2009 y Resolución 000779 de 2006 del Ministerio de Protección Social. Las variedades CC 11-600 y CC 00-3267 presentaron el mejor comportamiento agroindustrial en el primer ciclo productivo

Linfoma de linfocitos pequeños/leucemia linfocítica crónica

A female patient of 70 years old, personal medical history of bronchial asthma, high blood pressure and diabetes mellitus type 2 with chronic renal failure stage V secondary to this, multiple entries in hospital developing respiratory sepsis and need for peritoneal dialysis. It was found giant splenomegaly in imaging study during one of the entries. She evolved unfavorably with hypotension, fever, diffuse abdominal pain. The pathological findings showed a lymphoma of small lymphocytes/chronic lymphocytic leukemia cells. Stage IV. With infiltration to multiple viscera, including: lymph nodes, liver, spleen, lung, kidney and serous .The presence of pseudofoliculos is considered a morphological feature almost absolutely pathognomonic of the disease.Se trata de una paciente femenina de 70 años, con antecedentes patológicos personales de asma bronquial, hipertensión arterial y diabetes mellitus tipo 2, con insuficiencia renal crónica estadio V secundaria a la diabetes, múltiples ingresos por cuadro de sepsis respiratoria y necesidad de diálisis peritoneal. Se constató esplenomegalia gigante en estudio imagenológico durante uno de los ingresos.  Evolucionó desfavorablemente con hipotensión, fiebre y dolor abdominal difuso. Los hallazgos anatomopatológicos mostraron un linfoma de linfocitos pequeños/leucemia linfocítica crónica, estadio IV, con infiltración a múltiples vísceras: ganglios linfáticos, hígado, bazo, pulmón, riñones y serosas. La presencia de pseudofolículos se considera un rasgo morfológico casi absolutamente patognomónico de la enfermedad

Effect of the concentration of magnetite on the structure, electrical and magnetic properties of a polyester resin-based composite

Se reporta el efecto de la concentración de polvos de magnetita (Fe3O4) sobre las propiedades eléctricas y magnéticas de un material compuesto a base de resina de poliéster termoestable. Las muestras se elaboraron mediante el método de colado manual en concentraciones de: 60-40, 70-30, 80-20, 90-10 y 100-0 (% en peso), donde la fase mayoritaria es la resina y la minoritaria los óxidos de Fe3O4. La estructura cristalina se estudió usando la técnica de difracción de rayos X y la caracterización superficial tuvo lugar a través de la técnica de microscopía electrónica de barrido. Se midió la respuesta eléctrica por medio de curvas de polarización eléctrica en función del campo eléctrico y de resistividad eléctrica volumétrica a través de un electrómetro. La respuesta magnética se determinó mediante curvas de magnetización en función de la intensidad de campo magnético aplicado y en función de la temperatura. El análisis estructural indica que el porcentaje de cristalinidad aumenta a medida que se adiciona la concentración de Fe3O4 a las muestras. La caracterización eléctrica del material evidencia que la resistividad volumétrica disminuye con el incremento de magnetita, mostrando una transición aislante-conductor, con valores de la constante dieléctrica cada vez mayores. La caracterización magnética evidencia un aumento lineal de la magnetización de saturación y del momento magnético en función de la cantidad de magnetita adicionada a la matriz polimérica, mientras que la coercitividad evidencia comportamientos de materiales magnéticos blandos tanto en T˃TV como en T<TV, donde TV representa la temperatura de Verwey.This study reports the effect of the concentration of magnetite powders (Fe3O4) on the electrical and magnetic properties of a resin-based composite of thermoset polyester. The samples were prepared by the casting method at different concentrations: 60-40, 70-30, 80-20, 90-10 and 100-0 (% in weight), where the primary phase was resin and the secondary, Fe3O4 powders. The crystalline structure was studied using X-ray diffraction and surface characterization was carried out applying the scanning electron microscopy technique. The electrical response was measured by electric polarization curves as a function of the electric field; and the volumetric electrical resistivity, by an electrometer. The magnetic response was determined by magnetization curves as a function of temperature and intensity of the applied magnetic field. The structural analysis indicates that crystallinity increases as higher concentrations of Fe3O4 are added to the samples. The electrical characterization of the material reveals that the volumetric resistivity decreases as the content of magnetite increases. These reactions indicate an insulation-conductor transition with increasing dielectric constant values. The magnetic characterization presents a linear increase of the saturation of magnetization and magnetic moment as a function of the amount of magnetite added to the polymer matrix, whereas the coercivity shows behaviors of soft magnetic materials for T ˃ Tv and for T < Tv, where Tv represents the temperature of Verwey

Financial Stability Report - September 2015

From this edition, the Financial Stability Report will have fewer pages with some changes in its structure. The purpose of this change is to present the most relevant facts of the financial system and their implications on the financial stability. This allows displaying the analysis more concisely and clearly, as it will focus on describing the evolution of the variables that have the greatest impact on the performance of the financial system, for estimating then the effect of a possible materialization of these risks on the financial health of the institutions. The changing dynamics of the risks faced by the financial system implies that the content of the Report adopts this new structure; therefore, some analyses and series that were regularly included will not necessarily be in each issue. However, the statistical annex that accompanies the publication of the Report will continue to present the series that were traditionally included, regardless of whether or not they are part of the content of the Report. In this way we expect to contribute in a more comprehensive way to the study and analysis of the stability of the Colombian financial system. Executive Summary During the first half of 2015, the main advanced economies showed a slow recovery on their growth, while emerging economies continued with their slowdown trend. Domestic demand in the United States allowed for stabilization on its average growth for the first half of the year, while other developed economies such as the United Kingdom, the euro zone, and Japan showed a more gradual recovery. On the other hand, the Chinese economy exhibited the lowest growth rate in five years, which has resulted in lower global dynamism. This has led to a fall in prices of the main export goods of some Latin American economies, especially oil, whose price has also responded to a larger global supply. The decrease in the terms of trade of the Latin American economies has had an impact on national income, domestic demand, and growth. This scenario has been reflected in increases in sovereign risk spreads, devaluations of stock indices, and depreciation of the exchange rates of most countries in the region. For Colombia, the fall in oil prices has also led to a decline in the terms of trade, resulting in pressure on the dynamics of national income. Additionally, the lower demand for exports helped to widen the current account deficit. This affected the prospects and economic growth of the country during the first half of 2015. This economic context could have an impact on the payment capacity of debtors and on the valuation of investments, affecting the soundness of the financial system. However, the results of the analysis featured in this edition of the Report show that, facing an adverse scenario, the vulnerability of the financial system in terms of solvency and liquidity is low. The analysis of the current situation of credit institutions (CI) shows that growth of the gross loan portfolio remained relatively stable, as well as the loan portfolio quality indicators, except for microcredit, which showed a decrease in these indicators. Regarding liabilities, traditional sources of funding have lost market share versus non-traditional ones (bonds, money market operations and in the interbank market), but still represent more than 70%. Moreover, the solvency indicator remained relatively stable. As for non-banking financial institutions (NBFI), the slowdown observed during the first six months of 2015 in the real annual growth of the assets total, both in the proprietary and third party position, stands out. The analysis of the main debtors of the financial system shows that indebtedness of the private corporate sector has increased in the last year, mostly driven by an increase in the debt balance with domestic and foreign financial institutions. However, the increase in this latter source of funding has been influenced by the depreciation of the Colombian peso vis-à-vis the US dollar since mid-2014. The financial indicators reflected a favorable behavior with respect to the historical average, except for the profitability indicators; although they were below the average, they have shown improvement in the last year. By economic sector, it is noted that the firms focused on farming, mining and transportation activities recorded the highest levels of risk perception by credit institutions, and the largest increases in default levels with respect to those observed in December 2014. Meanwhile, households have shown an increase in the financial burden, mainly due to growth in the consumer loan portfolio, in which the modalities of credit card, payroll deductible loan, revolving and vehicle loan are those that have reported greater increases in risk indicators. On the side of investments that could be affected by the devaluation in the portfolio of credit institutions and non-banking financial institutions (NBFI), the largest share of public debt securities, variable-yield securities and domestic private debt securities is highlighted. The value of these portfolios fell between February and August 2015, driven by the devaluation in the market of these investments throughout the year. Furthermore, the analysis of the liquidity risk indicator (LRI) shows that all intermediaries showed adequate levels and exhibit a stable behavior. Likewise, the fragility analysis of the financial system associated with the increase in the use of non-traditional funding sources does not evidence a greater exposure to liquidity risk. Stress tests assess the impact of the possible joint materialization of credit and market risks, and reveal that neither the aggregate solvency indicator, nor the liquidity risk indicator (LRI) of the system would be below the established legal limits. The entities that result more individually affected have a low share in the total assets of the credit institutions; therefore, a risk to the financial system as a whole is not observed. José Darío Uribe Governo

La consulta previa y su influencia en los proyectos de interés nacional estratégico en Colombia

Artículo de investigaciónLa consulta previa es un derecho fundamental que consiste en un mecanismo de participación de las comunidades étnicas e indígenas sobre las medidas administrativas o legislativas que pueden afectar su integridad social, cultural y económica, entre otros. El desarrollo que este mecanismo ha presentado en Colombia, según cifras del Ministerio del Interior (2018) puede calificarse como desmedido. En este sentido, es necesario realizar un análisis acerca del exceso de consultas previas presentadas hoy en día en Colombia. Lo anterior, tiene como finalidad identificar las posibles mejoras que pueden desarrollarse a través de la reglamentación consiente de los procesos de consulta previa, a partir de la identificación real de las afectaciones que puede constituir cada proyecto (PINES). Ponderando el interés general y la necesidad de los proyectos que se encuentran en marcha.1. INTRODUCCIÓN 2. LA CONSULTA PREVIA COMO DERECHO FUNDAMENTAL 3. FUNDAMENTO CONSTITUCIONAL DE LA CONSULTA PREVIA 4. AUTODETERMINACIÓN, CONSENTIMIENTO PREVIO LIBRE E INFORMADO DE LAS COMUNIDADES ÉTNICAS CONCLUSIONES REFERENCIAS 5. PROYECTOS DE INTERÉS NACIONAL Y ESTRATÉGICOS – PINES 6. LA CONSULTA PREVIA Y LOS PROYECTOS DE INTERÉS NACIONAL Y ESTRATÉGICOS – PINES. 7. LA CONSULTA PREVIA Y LA CONSULTA POPULAR Y SU INFLUENCIA EN EL DESARROLLO DEL PAÍSPregradoAbogad