1,304 research outputs found
Aplicación del modelo modergis en el uso sostenible en la dendroenergía y los biocombustibles para países en vía de desarrollo- caso Colombia.
Numerosos países en vía de desarrollo caso Colombia, contienen un enorme potencial de recursos en energías
renovables como la dendroenergía incluidos los biocombustibles, pero no se utilizan en gran magnitud ni se
han incorporado al Mix Energético Nacional debido a la falta de herramientas que las evalué e integre de
manera armónico y con criterio sostenible. En tal sentido la Universidad Nacional de Colombia y el Centro de
Investigaciones Energéticas Medioambientales y Tecnológicas - CIEMAT de España, han desarrollado
conjuntamente una herramienta de planificación energética sostenible denominada - MODERGIS - que tiene
como objeto la incorporación, evaluación y análisis de energías renovables con énfasis a la dendroenergía y los
biocombustibles utilizando las técnicas de los Sistemas de Información Geográfica - SIG, como instrumento
alternativo de planificación y uso sostenible ambiental, social, económico y cultural del uso del suelo. El
modelo esta conformado por tres componentes: ENERDEM modelo de demanda- oferta de energía, ENERSIG:
espacialización e integración de energías renovables mediante los Sistemas de Información Geográfica - SIG
y ENERSOS modelo basado en métodos de análisis multiobjetivo tendientes a optimizar las dimensiones de la
sostenibilidad de las fuentes energética, incorporando el análisis de ciclo de vida.
Los resultados preliminares del modelo presentan 6.8 Millones de hectáreas factibles en el uso de la
Dendroenergía, el cual significaría un potencial de 4400 MW instalables si se dedicara en la producción de
energía eléctrica. En biocombustibles el Biodiesel de palma de aceite arroja un potencial de 1017 millones de
barriles y 54 millones de barriles de etanol de caña de azúcar, el cual justificaría proporciones de
abastecimiento interno con las mezclas de E10 y B5, quedando un gran potencial para interferir el mercado
internacional, lo cual con la metodología de ModerGIS tiene incluido los criterios de sostenibilidad que son
necesarios para ingresar a estos mercados.An essential element to reach sustainable development is an appropriate and reliable energy supply. This
helps to eradicate poverty, improve human welfare, and to raise quality of life in the population. However, many
regions in the world do not have a reliable supply, and its use exceeds economic limits, creating a dichotomy
between growth and sustainability. World institutons such as United Nations and its organization UNESCO,
have demonstrated that current energy production and consumption models are not sustainable in a medium
term.
Many countries, especially those that are in development such as Colombia, have a great potential of
renewable energy resources that have not been used or incorporated into the energy mix due to the lack of
tools to evaluate and to integrate them with a sustainability criteria. Then, “Universidad Nacional de Colombia”
(Colombia) and “Centro de Investigaciones Energéticas Medioambientales y Tecnológicas – CIEMAT” (Spain)
have jointly developed an integrated energy planning tool named MODERGIS. Its objective is to incorporate,
evaluate and analyze renewable resources such as wood energy including biofuels. This model comprises
three constitutive elements: an energy supply-demand model (ENERDEM), an integration and space definition
of renewable energy through geographic information systems (ENERSIG), and a multi-objectiveanalysis to
optimize sustainability dimensions of energy sources (ENERSOS).
The current paper shows some of the preliminary results of this model, and discusses on the methodological
issues faced during its development. Further and more expanded results are expected to be published in the
near future
A forced migration due to covid19 from a face-to-face university education service to a total online learning management system support: UDELAS-Panamá study case
The Covid-19 pandemic forced the Specialized University of the Americas (UDELAS, Panamá) to transform their educational service from almost 100% face-to-face to 100% virtual in approximately three weeks. This change involved creating 2,500 virtual courses and integrating nearly 9,000 students and 1,200 teachers into them. The research question to answer: Is it possible to schedule a proposed Learning Management System (LMS) tested on the go, in two effective months to institutionally can adopting latter an effective teaching-learning process total online? For testing which LMS online service to choose, two types of well-known LMS were selected: Moodle, which is an open source LMS centralized with a complete control over its components and services, and Google's Classroom, as a decentralized LMS running essentially in the cloud, which is conducive to a user/personal management, avoiding in the short term, to attend many hardware and software technical issues. Under a methodological process alike Agile style, the expansion of technological capabilities in the Moodle implementation took three weeks. In parallel, to implement Classroom, 12,000 institutional Google accounts were generated using the G Suite for Education license (in agreement with Google Mexico chapter). An institutional email account was established as the digital identity of professors and students, throughout they can access both LMSs. In addition, a group of the professors chose to combine applications instead of using Moodle or Classroom alone, it was called the combined option
A review of electrical metering accuracy standards in the context of dynamic power quality conditions of the grid
Numerous changes in electrical grid schemes, like the inclusion of renewable energy, the rise of non-linear loads and the emergence of electric vehicle charging, increases variable power quality conditions of the grid. In this dynamic scenario where energy could flow in both directions and the waveforms could be highly distorted, accuracy becomes a crucial factor for the correct measurement of electrical energy and power values. Errors in the assessment of these values have significant ramifications for revenue, billing and/or control. This non-ideal power quality scenario produces an error in electricity meters, that is not yet well known since there is no standardised procedure to calibrate meters under typical or emerging distorted waveform conditions. Current standards relevant for revenue energy meters like EN 50470-3:2006 allows measurements error up to ±2.5% while local regulations could be even more permissive. In order to establish an electricity fair trade market and meet expectations from consumers and utilities, electricity meters should arguably comply with higher accuracy standards. In this paper, the pertinence and possible impact of including tests under distorted waveform conditions, as well as new accuracy requirements on standards applicable to electricity meters for billing purposes will be discussed
Challenges for smart electricity meters due to dynamic power quality conditions of the grid : a review
During the last few years, Smart Electricity Meters have been deployed in several countries all around the world, replacing the trustable Electromechanical meter and even other electronic meters. Since the early deployments, many concerns and complaints from customers which do not trust Smart Meters accuracy have appeared. As a result, researchers of different institutions have been testing electricity meters under distorted waveform conditions and proposing methods to calibrate such meters in a more representative real world operative conditions. Applicable accuracy standards and regulations indicate a maximum distortion factor of 3% of the sinusoidal waveform for voltage and current during the calibration, which is not representative of many modern dynamic power quality scenarios. New tests and recommendations have been issued by regulatory bodies, but they are still not mandatory for meters to be certified. With many changes upcoming in the near future for the electrical Smart Grid like the inclusion of renewables, increasing non-linear loads, electric charging vehicles and other emerging technologies, the power quality conditions of the grid is expected to be significantly affected. In this paper, a review of the current and upcoming challenges for the smart meters is presented
Desarrollo de un Modulador QPSK utilizando entorno Integrado de Trabajo
En este trabajo se presenta una aplicación de prototipado rápido de sistemas digitales, diseñando un modulador para comunicaciones digitales del tipo Qudrature Phase Shit Key (QPSK). Se realiza el diseño en alto nivel de abstracción por medio de una herramienta como PeaCE, hasta llegar a una implementación en un microcontrolador de 8 bits, para lo cual se hace uso del Entorno Integrado de Trabajo (EIT), donde se combinan distintas herramientas EDA debidamente relacionadas por medio de distintas interfases de software, que definen el flujo de diseño adoptado
Variable Intrinsic Absorption in Mrk 279
We examine the variability in the intrinsic absorption in the Seyfert 1
galaxy Mrk 279 using three epochs of observations from the Far Ultraviolet
Spectroscopic Explorer (FUSE) and two epochs of observations with the Space
Telescope Imaging Spectrograph on the Hubble Space Telescope. Rather than
finding simple photoionization responses of the absorbing gas to changes in the
underlying continuum, the observed changes in the absorption profiles can be
understood more clearly if the effective covering fraction of the gas in all
emission components, continuum and broad and intermediate velocity width
emission lines, is accounted for. While we do not uniquely solve for all of
these separate covering fractions and the ionic column densities using the
spectral data, we examine the parameter space using previously well-constrained
solutions for continuum and single emission component covering fractions.
Assuming full coverage of the continuum, we find that of the two velocity
components of the Mrk 279 absorption most likely associated with its outflow,
one likely has zero coverage of the intermediate line region while the other
does not. For each component, however, the broad line region is more fully
covered than the intermediate line region. Changes in the O VI column densities
are unconstrained due to saturation, but we show that small changes in the
nonsaturated C IV and N V column densities are consistent with the outflow gas
having zero or partial covering of the intermediate line region and an
ionization parameter changing from ~0.01 to ~0.1 from 2002 to 2003 as the UV
continuum flux increased by a factor of ~8. The absence of a change in the C
III absorbing column density is attributed to this species arising outside the
Mrk 279 outflow.Comment: 36 pages, 18 figures, accepted to Ap
Variables de influencia en la productividad de biomasa de matorral en la mancomunidad de El Alto Jarama-Atazar
La situación energética actual, caracterizada por la búsqueda de nuevas fuentes de energía, sustitutivas de los combustibles fósiles tradicionales y menos agresivas con el medio ambiente, ha hecho necesaria la puesta en marcha de políticas y acuerdos a nivel mundial, que buscan reducir la contaminación y fomentar las energías renovables. La biomasa, recurso renovable perteneciente a cada país y con un poder calorífico suficientemente alto como para emplearse energéticamente, surge como alternativa a dichos combustibles fósiles.
Estos aspectos han convertido el estudio del potencial biomásico de los montes en uno de los pasos previos imprescindibles para cualquier proyecto vinculado al desarrollo de las bioenergías.
Sin embargo, la evaluación de la biomasa encierra numerosas dificultades, dado que como recurso vegetal y renovable que es, presenta un carácter variable, cualitativa y cuantitativamente. Este factor, junto a la complejidad de estimar el potencial biomásico de grandes extensiones, provoca que únicamente se calcule la biomasa arbórea, en detrimento de la arbustiva, proporcionando un valor generalmente más bajo del realmente disponible en cada zona.
Este estudio establece una metodología más precisa para el cálculo de la biomasa potencial generada por el matorral, en una determinada zona de estudio (Mancomunidad de El Alto Jarama-Atazar).____________________________________The present situation in the energy field is mainly characterized by the constant search of new energy sources, traditional fossil fuel substitutive and less aggressive towards the environment. All this has favoured the implementation of policies and worldwide agreements to reduce pollution and to promote Renewable Energies. The Biomass, a renewable resource belonging to each country and with a sufficiently high heating value to use energetically, arises as an alternative to the above mentioned fossil fuels.
These aspects have turned the study of the forestry biomass resources into one of the previous essential steps of any project related to the development of Bioenergy.
However, Biomass quantifying has numerous difficulties given that as vegetable and as renewable resource, it presents a changeable character, both qualitatively and quantitatively. In addition the impossibility to estimate the Biomass potential in large extensions causes that only arboreal biomass to be calculated, to the detriment of the bush tree, and therefore, generally the estimation provides a value that is minor than the real one.
This study tries to establish a more accurate methodology for the calculation of the potential Biomass generated by the thickets in a specific study zone (Mancomunidad de El Alto Jarama-Atazar)
Educación y medioambiente : Fuentes de energia renovables: la biomasa del olivar como recurso didáctico
Precise OBS location at the sea bottom in active seismic profiles using the air gun shot records
The Norcaribe campaign, in November – December 2013, funded by
Spanish Ministry of Innovation and Science (Norcaribe Project CGL2010-17715),
was performed on board of the Spanish research vessel “Sarmiento de Gamboa”
around the Hispaniola island, also with the participation of the Dominic Republic
Navy patrol vessels and several Haiti and Dominic Republic institutions. During
the campaign, a 200 km long, wide-amgle refraction seismic profile was carried
out crossing the Beata ridge. The air gun signal (5100 ci) was recorded by 15 OBSs
deployed along the seismic line in water depths between 2.300 meters and 4.320
meters. To obtain the section records, the OBS position is needed, usually the
deployment location is used, but the OBS can drift while is sinking due to the deep
oceanic currents. The recovery locations at surface could provide information about
the drift, assuming a constant sea current since the deployment to the recovery, but
it is imprecise. In this work we show a method to obtain a precise location of the
OBS at the sea bottom using a high-resolution bathymetry and the OBS record of
the closest air gun shots of the profile. Also, the preliminary results for the Norcaribe
campaign (Beata ridge profile) are shown.Peer Reviewe
El apoyo virtual a la docencia reglada como medio para conseguir el cambio de actitud de los estudiantes universitarios hacia la Ciencia
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