2,644 research outputs found
Fertilización nitrogenada, línea base y proyecciones de gases de efecto invernadero en Colombia
El taller sobre emisiones por el uso de fertilizantes nitrogenados, línea base y proyecciones de gases de efecto invernadero (GEI) en Colombia, se enmarca dentro del proyecto “Resultados de investigación para informar las estrategias de desarrollo bajo en emisiones en Colombia”, el cual contempla dentro de sus objetivos el fortalecimiento de la construcción de los inventarios de gases de efecto invernadero en el país mediante el mejoramiento de las estimaciones de N2O del suelo asociadas a fertilizantes nitrogenados aplicados en los diferentes sistemas de cultivos. Además, el proyecto busca consolidar el uso de los resultados de la investigación generada para el fortalecimiento de políticas públicas como la Contribución Nacionalmente Determinada (NDC), la Estrategia Colombiana de Desarrollo Bajo en Carbono (ECDBC) y el plan sectorial de mitigación
Nitrogen fertilization, baseline and projections of greenhouse gases in Colombia
The workshop on emissions from the use of nitrogen fertilizers, baseline and greenhouse gas (GHG) projections in Colombia includes among its objectives the strengthening of the development of greenhouse gas inventories in the country through the improvement of the N2O estimates of the soil associated with nitrogen fertilizers applied in the different crop systems. In addition, the project seeks to consolidate the use of the results of the research generated to strengthen public policies such as the Nationally Determined Contribution (NDC), the Colombian Low Carbon Development Strategy (ECDBC) and the sector mitigation plan
Timing for outcrossing: circadian clock regulates floral rhythms with large fitness consequences
Like most organisms, plants need to keep a daily rhythm to synchronize their inner functions to the available energy and nutrients; even due to its sessile nature it’s especially important for a large group to find ways to reproduce by outcrossing. The endogenous clock regulates metabolic processes related to the synchronization of plant traits that allows its survival and successful reproduction in pollinator dependent plants. In this work, the circadian clock genes in Nicotiana attenuata were identified and found to have a conserved function, as demonstrated by yeast two-hybrid assays and a similar hypocotyl length phenotypes on transformed Arabidopsis thaliana plants using N. attenuata transferred genes. Under long day conditions (LD) NaLHY and NaTOC1 peak at dawn and dusk, respectively, without NaZTL having marked oscillations like other plant models. The silencing of circadian genes in N. attenuata using inverted repeat (ir) technique showed similar clock transcription profile alterations of NaCAB2 and hypocotyl growth alteration as in the established clock model. Yet, irTOC1 plants had a delayed elongation and flowering under LD unlike some other model plant accessions, but it is attributable to a different habitat and genetic background, as seen in cross latitudinal studies of other species. Floral traits under circadian control are relevant to synchronize the display and scent emission of N. attenuata with its night-pollinator Manduca sexta. Flower vertical movement temporally excludes other pollinators by reduced conspicuousness. The right synchronization improves outcrossing by M. sexta in the field since dysrhythmic floral traits decreased pollination rate. However, a lack of regulation caused basically arrhythmic floral traits since irZTL had unexpected advantages during day-time outcrossing in the field due to the recruitment of day-active pollinators that provided similar reproductive results as night-pollinator dependent plants
Taller: hablemos y construyamos juntos temas clave de objetivos de desarrollo sostenible, cambio climático y acciones de mitigación en nuestro territorio. Objetivos de Desarrollo Sostenible
Taller: hablemos y construyamos juntos temas claves de objetivos de desarrollo sostenible, cambio climático y acciones de mitigación en nuestro teritorio
Taller: hablemos y construyamos juntos temas clave de objetivos de desarrollo sostenible, cambio climático y acciones de mitigación en nuestro territorio. Introducción al Cambio climático
Evaluación del riesgo agroclimático en el cultivo de maíz (Zea Mays) en los departamentos de Córdoba y Meta
Fueron identificados y evaluados los riesgos de origen agrometeorológicos para el cultivo del maíz (Zea mays) en zonas productoras de los departamentos de Córdoba y Meta, mediante la metodología de función de mérito se seleccionaron municipios con información climática, de suelos y con superficies importantes de maíz cosechado para determinar el área de estudio. Para el análisis climático, se emplearon series diarias de las variables meteorológicas de precipitación, temperatura máxima, temperatura mínima, humedad relativa, evaporación y brillo solar, que permitieron la caracterización climática de cada una de las regiones y la generación de balances hídricos. Las variaciones interanuales de la precipitación se correlacionaron con análisis de tele-conexiones que permitieron correlacionar 33 índices de variabilidad climática con las series de precipitación, lo que permitió generar balances hídricos para los diferentes escenarios. Se generaron simulaciones de rendimientos del cultivo de maíz para la serie 1986-2014, con una variedad comercial validada en Colombia para diferentes departamentos incluyendo Córdoba y Meta, estas simulaciones permitieron generar diferentes estrategias para mitigar los diferentes riesgos agroclimáticos en el área de estudio.Abstract. It was identified and analyzed Agrometeorological risks for maize crop (Zea mays) in producing areas of the departments Córdoba and Meta, using the methodology of merit function were selected municipalities with climatic information, soils and areas of maize harvested to determine The area of study. For the climatic analysis, daily series of the meteorological variables of rainfall, maximum temperature, minimum temperature, relative humidity, evaporation and solar brightness were used, that allowed the climatic characterization of each one of the regions and the generation of water balances. The interannual variations of precipitation were correlated with tele-connection analysis that allowed correlating 33 indexes of climatic variability with the precipitation series, which allowed the generation of water balances for the different scenarios. Simulations of maize crop yields were generated for the 1986-2014 series, with a comercial variety validated in Colombia for different departments including Córdoba and Meta, these simulations allowed to generate different strategies to mitigate the different agroclimatic risks in the study areaMaestrí
Percepción sobre bullying en un colegio público de Pereira identificado en el descanso pedagógico
La metodología fue Histórico-Hermenéutico, el diseño fenomenológico, este pretendió percibir en un entorno natural el fenómeno del Bullying de un Colegio Público de Pereira. Se contó con una muestra intencionada para la entrevista de 12 personajes claves, identificados gracias a la observación no participante en el descanso pedagógico. El criterio de inclusión fue el muestreo teórico sobre los actores del Acoso Escolar. El análisis se realizó a través de codificación abierta, axial y selectiva buscando la saturación y así llegar a las siguientes categorías. Los estudiantes, docentes y administrativos conciben el Bullying como una agresión verbal, abuso físico y discriminación por raza, credo o preferencias sexuales, los tipos de Bullying fueron verbal, físico, psicológico, social y cibernético, los estudiantes se identifican, como observadores, víctimas y victimarios, el Bullying se presenta en zonas de juego y aulas de clase, los estudiantes acuden a docentes y compañeros, los grados en donde se presenta son sextos, séptimos, octavos y novenos, el manejo que la institución da es con, talleres y acuerdos. Se encontraron nuevas categorías. Primero Información sobre el acoso en actividades de competencia deportiva en el momento que se enfrentaban por alguna meta u objetivo; de segundo, se identificó agresión de niñas a causa de peleas por los novios, debido a los cambios que se producen de la niñez a la adolescencia; tercero bruscos percibidos por los observadores. Se identifica como en la actualidad se presenta el Bullying y requiere prevención, detección y atención por parte de la comunidad académica.The methodology was historical-hermeneutic, phenomenological design, the pretended sense in a natural phenomenon of a Public School Bullying Pereira. It featured a purposive sample to interview 12 key characters, identified through non-participant observation in the pedagogical break. The inclusion criterion was theoretical sampling on Bullying actors. The analysis was performed using open, axial and selective coding looking saturation and thus reaches the following categories. Students, faculty and staff conceive Bullying as a verbal assault, physical abuse and discrimination by race, creed or sexual preference, the types of bullying were verbal, physical, psychological, social and cyber, students are identified as observers, victims and perpetrators, Bullying occurs in play areas and classrooms, students flock to teachers and classmates, grades where it occurs are sixth, seventh, eighth and ninth, the management that the institution gives is with workshops and agreements. New categories were found. First Information harassment activities sports competition when they faced for some goal or objective, second Aggression girls identified because of fights over boyfriends, due to changes that occur in childhood to adolescence; sudden third perceived by observers. It is identified as currently Bullying occurs and requires prevention, detection and attention from the academic community
Design and efficiency of a small-scale woodchip furnace
Although advances have been made in combustion efficiency in large-scale woodchip furnaces, less experimental results are available at the <20 kW range. Compact feed systems, as well as optimized grates and combustor chambers, continue to represent a challenge for the wider use of low-cost wood chips. This study describes the design and testing of a small-scale woodchip furnace that operates at a range of 9-18 kW. The efficiency test takes account of the feedstock Eucalyptus nitens, with three moisture contents and the combination of different air excess (λ) and primary/secondary air ratios. The results reveal a maximum of combustion efficiency of 85% for the low moisture content sample (16%) at λ=1,5 and 82% for samples with 29% and 40% moisture content, at λ= 2,0 and 2,1 respectively. The integrated heat exchanger proved to be highly efficient by reducing gas temperature by up to 69% prior to its exit
Flexible Wing
Flutter is an interesting phenomenon that consists of a certain component in a system vibrating at an uncontrollable frequency. Aircraft, due to the circumstances they usually encounter, tend to present this physical condition. Throughout history, aircraft manufacturers have studied flutter and generated models for their particular designs. However, no general analyses and methodologies have been developed for flutter. To conduct this research, a wing was designed and constructed to study excessive vibrations and aeroelastic behaviors, required for flexible flight controls. First, it was necessary to perform material testing to define the best dimensions of each component of the wing. Destructive tests were performed to determine the stiffness and flexibility of naked foam, naked foam with epoxy, and a sandwich composite component made of carbon fiber and foam. Next, the main wing was constructed and placed into the wind tunnel. During testing, flutter was developed when the fan blades were rotating at a speed of 300 rpm. The wing generated rapid and unnatural upward and downward motions, deflecting at a precise frequency until the whole system failed. Unfortunately, this part of the experiment occurred too quickly, so it was not possible to gather enough data. For that reason, this experiment needs to be performed again in a more controlled environment. Furthermore, additional material testing is currently being done to improve the wing structure before the wing is tested again
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