Universidad Tecnológica de Bolívar
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Electricity retail market and accountability-based strategic bidding model with short-term energy storage considering the uncertainty of consumer demand response
No full textElectricity retailers participate in electricity markets as intermediaries between wholesale and retail markets. They acquire energy on the wholesale side by participating in next-day markets and the pool of power. On the retail side, they make contracts with consumers in order to meet their energy demand at a fixed price for a set period of time –generally a year. To maximize profit in planning, a retailer must choose the best strategy, which should be able to reduce the cost of purchasing energy in the wholesale market while simultaneously determining the best selling price for consumers. Customers may choose a different retailer if the selling price is too high, and the retailer may take a loss if the price is too low. One of the issues that complicate retailers’ decision is the uncertain demand response parameters that affect profit. This paper contributes with a strategic bidding model for planning with short-term energy storage while considering the uncertainty of consumer demand response and load response programs simultaneously. GAMS and MATLAB are implemented in this research to analyze the data and review the results, which indicate that an increase in profit is expected to be greater than when the retailer uses only a load response program or a short-term energy storage system. As uncertainty grows, so does local price sensitivity, and, as a result, so does the predicted rate of profit. Profits from participatory reservation, energy, and regulation markets increase in the robust model, while profits from the common participatory market decrease, i.e., according to this study, which looked at both probabilistic and robust models of retail market participation. When a robust model is used, the overall profit is higher than that obtained from a probabilistic model. © 2022 The Author
The levels of knowledge for the curricular design of Law Schools
No full textLos resultados de aprendizaje previstos para los programas de las facultades de derecho determinan qué deben alcanzar quienes aprenden al finalizar el proceso de formación. No obstante, algunos de estos diseños curriculares no responden a un proceso de formulación reflexivo y consciente, lo que reduce la posibilidad de materializar los propósitos previstos para la educación jurídica de cada contexto. Con el ánimo de aportar a consolidar procesos reflexivos de diseño curricular, el presente artículo describe, en un primer lugar, los lineamientos para construir resultados de aprendizaje desde diversos niveles del conocimiento. Se trata de una sistematización teórica que, en un segundo lugar, es analizada desde las necesidades, intereses y exigencias de los actores de las facultades de derecho para aportar a procesos de formación de alta calidad. Es, por tanto, una propuesta que espera ser interpretada desde cada realidad con el fin de consolidar una educación jurídica desde y para la realidad profesional.Os resultados de aprendizagem esperados para os programas da faculdade
de direito determinam o que os alunos devem alcançar ao final do processo de treinamento. No entanto, alguns desses desenhos curriculares não respondem a um processo
de formulação reflexiva e consciente, o que reduz a possibilidade de concretização dos
propósitos pretendidos para o ensino jurídico em cada contexto. Com o objetivo de
contribuir para a consolidação de processos reflexivos de desenho curricular, este artigo
primeiramente descreve as diretrizes para a construção de resultados de aprendizagem
a partir de diferentes níveis de conhecimento. Trata-se de uma sistematização teórica
que em segundo lugar é analisada a partir das necessidades, interesses e demandas dos atores das faculdades de direito, para contribuir com processos formativos de qualidade.
É uma proposta que espera ser interpretada a partir de cada realidade para contribuir
para consolidar um ensino jurídico a partir e para a realidade profissional.The expected learning outcomes for law school programs determine what
learners should achieve by the end of the training process. However, some of these
curricular designs do not respond to a reflective and conscious formulation process,
which reduces the possibility of materializing the intended purposes for legal education
in each context. With the aim of contributing to consolidating reflective processes of
curricular design, this article first describes the guidelines for building learning results
from different levels of knowledge. It is a theoretical systematization that in a second
place is analyzed from the needs, interests and demands of the actors of the law schools,
to contribute to high quality training processes. It is a proposal that waits to be interpreted from each reality to contribute to consolidate a legal education from and for the
professional realityUniversidad Tecnológica de Bolíva
Análisis para la mejora del desempeño de colectores cilíndrico parabólicos basada en las condiciones operacionales y utilización de diferentes fluidos de transferencia de calor
No full textEste trabajo se centra en estudiar las posibilidades de optimización de los sistemas de concentración solar con colectores cilíndrico parabólicos (CCP) mediante el análisis basado en condiciones operacionales, así como la utilización de diferentes fluidos de transferencia de calor (HTF), con la finalidad de determinar las configuraciones que permitan obtener mejores condiciones de operación, y, aplicar dichos resultados a un caso de estudio en el que se analiza el suministro de calor de CCP para un sistema de destilación multiefecto (MED) diseñado para convertir agua de mar en agua potable, esto como una alternativa para abordar el desafío de escasez de agua en las comunidades indígenas de la Alta Guajira. La simulación del comportamiento térmico y exergético del CCP se realiza con el modelo matemático desarrollado en Engineer Equation Solver (EES). En el desarrollo del trabajo, se ha observado que una relación óptima entre la longitud de apertura y los diámetros del tubo receptor pueden generar mejoras en el rendimiento y el comportamiento del colector. Un ejemplo notable es el modelo de colector LS-2, el cual demostró un rendimiento térmico sobresaliente en comparación con los demás modelos evaluados cuando se trabajaba a temperaturas más elevadas. En general, las eficiencias térmicas se mantuvieron en un rango de 60% a 70%, mientras que las eficiencias exergética oscilaron entre el 30% y el 40%. Además, se pudo observar que las temperaturas de salida del colector se vieron afectadas por la longitud del mismo; al permitir que el fluido de transferencia de calor permanezca más tiempo en el sistema de tubos receptores se lograron temperaturas de salida más altas. Un ejemplo destacado es el colector ET100, el cual logró alcanzar temperaturas de 700°C con algunos gases y en el rango de los 500°C con algunos aceites térmicos, además de eficiencias exergéticas mayores. En cuanto a los HTF, el gas con mejor desempeño fue el hidrogeno (H2), mientras que para los aceites térmicos fue el Dowtherm A. También se encontró que la adición de nanopartículas tiene un claro impacto en el rendimiento de los colectores. Entre los nanofluidos evaluados, el Syltherm 800-MWCNT al 10% de volumen de concentración mostró el mayor porcentaje de mejoras en las eficiencias térmicas y exergéticas, con incrementos de 7,52% y 7,36%, respectivamente. En su punto de operación óptimo (350,9 °C, 0,0005 m3 /s), se lograron valores de eficiencia térmica de 71,84% y exergética de 40,94%. Finalmente, el análisis del calor suministrado por los CCP al sistema de desalinización MED nos permite determinar configuraciones óptimas que contribuyan a un aprovechamiento más eficiente del recurso solar disponible
Three-dimensional analysis of air-admission orifices in pipelines during hydraulic drainage events
No full textAir valves operate as protection devices in pipelines during drainage processes in order
to mitigate vacuum pressures and control the transient flows. Currently, different authors have
proposed one-dimensional models to predict the behaviour of orifices during filling and draining
events, which offer good numerical results. However, the three-dimensional dynamic behaviour of
air-admission orifices during drainage processes has not been studied in depth in the literature. In
this research, the effects of air inflow on an orifice installed in a single pipe during drainage events
are analysed using a three-dimensional computational fluid dynamics model by testing orifices with
diameters of 1.5 and 3.0 mm. This model was validated with different experimental measurements
associated to the vacuum pressure, obtaining good fits. The three-dimensional model predicts
additional information associated to the aerodynamic effects that occur during the air-admission
processes, which is studied. Subsonic flows are observed in different orifices with Mach numbers
between 0.18 and 0.30. In addition, it is shown that the larger-diameter orifice ensures a more effective
airflow control compared to the smaller-diameter orific
A New Weave in the Pattern
No full textEditor-in-Chief Andres Marrugo discusses the role of Large Language Models, like ChatGPT, in academic publishing, highlighting some practical applications, potential pitfalls, and the ethical considerations required for their responsible use in academia. © 2023 by the authors
A mixed-integer convex approximation for optimal load redistribution in bipolar DC networks with multiple constant power terminals
No full textThis paper proposes a mixed-integer convex model for optimal load-balancing in bipolar DC networks while considering multiple constant power terminals. The proposed convex model combines the Branch and Cut method with interior point optimization to solve the problem of optimal load balancing in bipolar DC networks. Additionally, the proposed convex model guarantees that global optimum of the problem is found, which ensures minimal power losses in the bipolar DC distribution grid branches, as the total monopolar load consumption has been balanced at the substation's terminals. In addition, an optimal load balancing improves the voltage profiles due to current redistribution between the positive and negative poles. Numerical results in the 21- and 85-bus test feeders and a comparison with three metaheuristic techniques show the effectiveness of the proposed convex model in reducing the total grid imbalance while minimizing the power losses and improving the voltage profiles
Love Thy Neighbor: La Vida Musical De Justo Almario
No full textPero el señor que nos trajo, él me decía: “Justico”, ellos acostumbraban llamarme así, Justico, “Justico,tú debes aprovechar, tú sabes, tú tienes la residencia, a ti te gusta mucho el jazz y la música…” y eso era cierto, yo realmente quería venir y estudiar aquí, así que me dijo: “tú necesitas irte, tú necesitas irte” (traducción propia).Y me acuerdo que el maestro Peña me decía: “Justo, tú tienes que irte, estás joven, te gusta, tienes esta actitud, el oído para escuchar estas cosas. Quiero que te vayas a los Estados Unidos y... [cambia a la voz del propio Antonio María Peñaloza] pero te voy a hacer una sola advertencia: si llegas a Nueva York, no te vayas pal barrio latino. Procura trabajar con unos señores monos, altos, pelo de candela, norteamericanos. Trabaja con los músicos norteamericanos, estudia con los músicos
norteamericanos, y cuando sepas muy bien porque has aprendido en cualquier academia de jazz de los Estados Unidos, entonces ahora sí puedes ir al barrio latino y comerte unos frijolitos a la cartagenera, un arroz con coco
Love Thy Neighbor: La Vida Musical De Justo Almario
No full textInterlude fue un disco al que se le hizo poca promoción. Por las múltiples ocupaciones de Justo, no se realizó una gira promocional y prácticamente no lo presentó en vivo, a pesar de lo cual, según él, algunos de los temas fueron programados en la radio local. Así como este disco había sido realizado por iniciativa de Roy Ayers y no propia, en 1985 la disquera cristiana con la que grababa Koinonia le encargó el que sería su segundo trabajo discográfico, al que tituló Forever Friends.
Escuchemos, en sus propias palabras, el origen y concepto del mismo y, en general, de toda su obra posterior
Diferencias en la calidad de vida relacionada con la salud, las funciones neuropsicológicas y el estado emocional entre niños y adolescentes con daño cerebral traumático leve y controles sanos
No full textLittle is known about the impact of mild traumatic brain injury (TBI) on the functioning of children in Latin America, especially regarding a broad construct called health-related quality of life (HRQoL). The objective of this study was to analyze the differences in HRQoL, neuropsychological functions and emotional state between a group of children and adolescents with mild TBI and a healthy control group. A case-control study was conducted in which 30 children and adolescents with mild TBI and their parents and a group of 30 healthy subjects participated. The results showed that participants with mild TBI had an HRQoL similar to the one of the general population of the same age and sex. At the cognitive level, the group with mild TBI had a lower processing speed and less work done in selective and sustained attention tasks; at the emotional and behavioral level, they exhibited more symptoms of anxiety, depression, withdrawal and social problems. © Asociación Española de Psicología Clínica y Psicopatologí
Valoration of the Synthetic Antioxidant Tris-(Diterbutyl-Phenol)-Phosphite (Irgafos P-168) from Industrial Wastewater and Application in Polypropylene Matrices to Minimize Its Thermal Degradation
No full textIndustrial wastewater from petrochemical processes is an essential source of the synthetic phenolic phosphite antioxidant (Irgafos P-168), which negatively affects the environment. For the determination and analysis of Irgafos P-168, DSC, HPLC-MS, and FTIR methodologies were used. Solid phase extraction (SPE) proved to be the best technique for extracting Irgafos from wastewater. HPLC-MS and SPE determined the repeatability, reproducibility, and linearity of the method and the SPE of the standards and samples. The relative standard deviations, errors, and correlation coefficients for the repeatability and reproducibility of the calibration curves were less than 4.4% and 4.2% and greater than 0.99955, respectively. The analysis of variance (ANOVA), using the Fisher method with confidence in 95% of the data, did not reveal significant differences between the mentioned parameters. The removal of the antioxidant from the wastewater by SPE showed recovery percentages higher than 91.03%, and the chemical characterization of this antioxidant by FTIR spectroscopy, DSC, TGA, and MS showed it to be structurally the same as the Irgafos P-168 molecule. The recovered Irgafos was added to the polypropylene matrix, significantly improving its oxidation times. An OIT analysis, performed using DSC, showed that the recovered Irgafos-blended polypropylene (PP) demonstrated oxidative degradation at 8 min. With the addition of the Irgafos, the oxidation time was 13 min. This increases the polypropylene’s useful life and minimizes the environmental impact of the wastewater