Universidad Tecnológica de Bolívar
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Development of films based on chitosan, gelatin and collagen extracted from bocachico scales (Prochilodus magdalenae)
No full textBiodegradable biopolymers from species of the animal kingdom or their byproducts are sus tainable as ecological materials due to their abundant supply and compatibility with the envi ronment. The research aims to obtain a biodegradable active material from chitosan, gelatin, and
collagen from bocachico scales (Prochilodus magdalenae). Regarding the methodology, films
were developed from gelatin, chitosan, and collagen from bocachico scales (Prochilodus mag dalenae) at different concentrations using glycerol as a plasticizer and citric acid as a cross-linker.
The films were obtained with the hydrated mass processed by compression molding and char acterized according to humidity, water solubility, contact angle, mechanical properties, and
structural properties. The results of the films showed a hydrophobic characteristic. First, the
chitosan-collagen (CS/CO) films showed a yellowish color, while the gelatin-collagen (Gel/CO)
films were transparent and less soluble than the gelatin-collagen (Gel/CO) films. Concerning
mechanical properties, gelatin films showed higher stiffness and tensile strength than chitosan
films. Furthermore, in the morphological analysis, more homogeneous chitosan films were ob tained by increasing the concentration of citric acid. In general, chitosan, gelatin, and collagen
extracted from the scales of the bocachico (Prochilodus magdalenae) are an alternative in the
application of films in the food industry
Windthrows Detection With Satellite Remote Sensing Data: A Comparison Among Sentinel-2, Planet, And Cosmo Sky-Med Data
No full textWind disturbances represent a great source of damage in forests, and an assessment of such damage is very important for adequate forest management. Remote sensing is an effective tool for this purpose and can be used by considering different data sources: active vs passive sensors. While passive sensors can provide a direct view of windthrows, they are often affected by clouds. Active sensors have the significant advantage of not being affected by the presence of clouds which can be prevalent in certain seasons in mountain areas. The objective of this study is to compare the capability of active (Cosmo SkyMed SAR sensor) and passive (Sentinel-2 and Planet sensors) data in detecting windthrows in different seasons of image acquisition. A study site was analysed, located in the Trentino-South Tyrol region (Italy), which was affected by the Vaia storm on 27-30 October 2018, which caused significant forest damage
Energetic and exergoeconomic evaluation of a stig cycle and cooled inlet air gas turbine powered by mixtures of natural gas and H2 in tropical climates
No full textUsing pure hydrogen (H2) or mixtures of H2 and natural gas in gas-fired power plants represents a viable route to decarbonize electric power generation. This study models a system designed to cool the air at the compressor inlet to 8.8 °C, achieve a flue gas oxygen percentage of 11.46 %, and produce 44.4 MW with a fuel mix ranging from 0 to 100 % H2 operating in tropical climates, where temperatures exceed 30 °C and relative humidity exceeds 80 %. The analysis is based on energy, exergy, and exergoeconomic balance to obtain performance indicators that characterize plant operations. The results show that with 100 % H2, the PCI increases by 144 % compared to 100 % natural gas. Furthermore, the energy analysis indicates that for every 10 % volume increase in the H2 fuel mix, the CO2 concentration decreased by 34 kg/m³, the NOx concentration increased by 1 kg/m³, the dew point temperature increased by 0.5 °C, the energy efficiency improved by 4.5 percentage points, the heat rate decreased by 7 %, and the specific fuel consumption decreased by 8.5 %. Furthermore, the total exergy destruction increased by 14.83 %, and the total exergy efficiency decreased by 2.7 percentage points. The exergoeconomic analysis shows that the specific cost of electric energy per GJ decreases by 10 % for H2 contents higher than 80 % by volume. This work demonstrates that generating energy from gas turbine power plants with lower CO2 equivalent emissions is possible. On the other hand, the effects of moisture content in exhaust gases and NOX are known due to the greater presence of H2 and higher temperature combustionUniversidad Tecnológica de Bolíva
Advanced control strategies for cleaner energy conversion in biomass gasification
No full textThe escalating climate crisis necessitates urgent and decisive action to mitigate greenhouse gas emissions. Gasification stands out as a highly adaptable process for energy conversion, capable of handling a wide range of feedstocks, from coal to biomass. The process plays a significant role in improving sustainability by converting these feedstocks into synthesic gas (syngas), which can be used as a cleaner energy source or as a building block for producing various chemicals. The utilization of syngas obtained through gasification not only reduces the reliance on fossil fuels but also helps in reducing greenhouse gases (GHGs), thereby contributing to a more sustainable energy landscape. To maintain optimal operational conditions and ensure the quality and safety of the product, an effective control system is crucial in the gasification process. This paper presents a comparative analysis of three control strategies applied to a numerical model of rice husk gasification: classical control, fuzzy logic control, and dynamic matrix control. The analysis is based on a comprehensive model that includes the equations necessary to capture the dynamic behavior of the gasification process across its various stages. The goal is to identify the most effective control strategy, and the performance of each control strategy is evaluated based on the integral of the absolute value of the error (IAE). The results indicatethat fuzzy logic control consistently outperforms classical control techniques, demonstrating superior disturbance rejection, enhanced stability, and overall improved control accuracy. These findings highlight the importance of selecting an appropriate advanced control strategy to optimize sustainable gasification processes
Self-Unit Commitment of Combined-Cycle Units with Real Operational Constraints
No full textEste artículo destaca la importancia de modelar con precisión las limitaciones operativas de las plantas de gas de ciclo combinado (CCGT por sus siglas en ingles) dentro de un marco de despacho económico. En la práctica, en Colombia, cuando reciben un despacho inicial por parte del Operador Independiente del Sistema (ISO por sus siglas en ingles), las plantas CCGT son operadas de acuerdo con los resultados de códigos de simulación heurística. Estas heurísticas a menudo omiten restricciones operativas técnicas, incluidas rampas de arranque en caliente, tibia o fría; las horas mínimas de operación requeridas para que una turbina de gas ponga en marcha una turbina de vapor; la relación entre el número despachado de turbinas de vapor y de gas; la distribución de carga entre turbinas de gas; y quemadores adicionales. La mayoría de los modelos de despacho económico en la literatura representan restricciones técnicas estándar como arranque, apagado, rampas de subida/bajada y, en algunos casos, incendios suplementarios. Sin embargo, normalmente pasan por alto otras limitaciones operativas de CCGT de la vida real, que se consideraron en este trabajo. Estas limitaciones son cruciales en los sistemas eléctricos interconectados para evitar daños a los equipos, lo que potencialmente puede dejar fuera de servicio las plantas CCGT y, en última instancia, conducir a menores costos operativos.This paper highlights the importance of accurately modeling the operational constraints of Combined-Cycle Gas Turbines (CCGTs) within a unit-commitment framework. In practice, in Colombia, when given an initial dispatch by the Independent System Operator, CCGT plants are operated according to the results of heuristic simulation codes. Such heuristics often omit technical operating constraints, including hot, warm, or cold startup ramps; the minimum operation hours required for a gas turbine to start a steam turbine; the relationship between the dispatched number of steam and gas turbines; the load distribution among gas turbines; and supplementary fires. Most unit-commitment models in the literature represent standard technical constraints like startup, shutdown, up/down ramps, and in some cases, supplementary fires. However, they typically overlook other real-life CCGT operating constraints, which were considered in this work. These constraints are crucial in integrated energy systems to avoid equipment damage, which can potentially put CCGT plants out of service and ultimately lead to lower operating costs
The use of cinematographic material as an educational enhancement to lectures in a university environment
No full textEn un curso universitario de psicología social (N = 146) en Cartagena de Indias
(Colombia) se introdujo un enfoque didáctico utilizando material cinematográfico de alta calidad,
concretamente 12 Angry Men (1957). El estudio pretendía determinar si el visionado de esta
película clásica mejoraría los resultados académicos y la satisfacción de los estudiantes, y
reduciría las tasas de abandono. Este objetivo se abordó mediante una comparación de clases
naturales (dos aulas por semestre) a lo largo de un año y medio. Inicialmente, todo el alumnado
realizó una evaluación de comprensión e interpretación de la película junto con una prueba
de conocimientos (pre-test). En las aulas más pequeñas, se impartieron clases tradicionales
(grupo de control), mientras que, en las aulas más grandes, el curso se impartió utilizando
la película (grupo experimental). Al final de la intervención, se registraron las puntuaciones
académicas y una encuesta de satisfacción de método mixto («post-test»). Los resultados de los
tres semestres mostraron que el alumnado expuesto a la película: (1) presentaba menores tasas
de abandono y (2) proporcionaba comentarios cualitativos más positivos. Además, obtenía mejores
calificaciones académicas y mayores puntuaciones de satisfacción, aunque las diferencias no fueron
estadísticamente significativas. A pesar de las limitaciones de los datos cuantitativos, los resultados
apoyan el uso continuado de material fílmico de alta calidad en el ámbito universitario colombiano
para ilustrar conceptos de psicología social.A didactic approach using high-quality film material, specifically 12 Angry Men (1957),
was introduced in a university social psychology course (N = 146) in Cartagena de Indias (Colombia).
The study aimed to determine if viewing this classic film would enhance academic outcomes and
student satisfaction, and reduce dropout rates. This objective was addressed through a comparison
of natural class (two classrooms per semester) over one and a half years. Initially, all students took
a film comprehension and interpretation assessment along with a knowledge test (pre-test). In
smaller classrooms, traditional lectures were conducted (control group), while in larger classrooms,
the course was taught using the film (experimental group). At the end of the intervention, academic
scores and a mixed-method satisfaction survey (post-test) were recorded. Results across three
semesters showed that students exposed to the film: (1) exhibited lower dropout rates, and (2)
provided more positive qualitative feedback. (In addition, they obtained better academic grades
and higher satisfaction scores, although the differences were not statistically significant. Despite
the limitations of the quantitative data, the results support the continued use of high quality film
material in the Colombian university setting to illustrate social psychology concepts
Fundamental right to love in Colombia: a rhetorical constitutional commitment with limited practical materialization
No full textLa Constitución Política colombiana de 1991 transforma el panorama jurídico existente hasta ese momento, dado que acoge un Estado Social de Derecho que clasifica a los derechos humanos en diferentes generaciones. La primera de esas generaciones corresponde a los derechos fundamentales, los cuales tienen la posibilidad de ser exigidos de manera inmediata a manera de mínimos necesarios para la subsistencia de cualquier persona. Así, y como una innovación disruptiva, esta norma superior consagra al amor como un derecho fundamental para los niños y las niñas. Sin embargo, su carácter indeterminado impide una materialización plena a través de acciones constitucionales, pues no es posible obligar a alguien a amar a otra persona. En consecuencia, en este artículo se delimita el alcance iusteórico de este derecho como un principio y valor constitucional, que solo podrá ser materializado a través de otros derechos según cada una de las realidades desde y para las cuales sea aplicable.The Colombian Political Constitution of 1991 transforms the legal landscape that existed until then, given that it embraces a Social State of Law that classifies human rights into different generations. The first of these generations corresponds to fundamental rights, which can be demanded immediately as the minimum necessary for the subsistence of any person. Thus, and as a disruptive innovation, this higher standard enshrines love as a fundamental right for boys and girls. However, its indeterminate nature prevents full materialization through constitutional actions, since it is not possible to force someone to love another person. Consequently, this article delimits the theoretical scope of this right as a constitutional principle and value, which can only be materialized through other rights according to each of the realities from and to which it is applicable.Universidad Tecnológica de BolívarI. INTRODUCCIÓN Y DISEÑO METODOLÓGICO. II. DELIMITACIÓN IUSTEÓRICA DEL DERECHO FUNDAMENTAL AL AMOR DESDE LAS NORMAS CONSTITUCIONALES COLOMBIANAS. III. ALCANCES SUSTANCIALES PARA MATERIALIZAR EL AMOR COMO MARCO IUSTEÓRICO. 1. El amor desde los derechos de primera generación que implican la congrua subsistencia. 2. El amor desde los derechos de segunda generación referentes a las relaciones en su contexto inmediato. 3. El amor desde los derechos de tercera generación que exigen una corresponsabilidad ambiental. IV. CONCLUSIONES. V. BIBLIOGRAFÍA
Classification of opening/closing hand motor imagery induced by left and right robotic gloves through EEG signals
No full textThis study presents a novel strategy for classifying Motor Imagery (MI) related to hand opening/closing actions using electroencephalography signals. This approach combines the passive motion induced by a robotic glove and action observation. Two groups of subjects executed a protocol based on left and right hand movement MI to address this. Subsequently, spectral features were used on and bands, and machine-learning algorithms were used for classification. The results showed better performance for right-hand motion recognition using k-Nearest Neighbors (kNN), which achieved the highest performance metrics of 0.71, 0.76, and 0.28 for Accuracy (ACC), true positive rate, and false positive rate, respectively. These findings demonstrate the feasibility of the proposed methodology for improving the recognition of MI tasks of the same limb, which can contribute to the design of more robust brain-computer interfaces for the enhancement of rehabilitation therapy for post-stroke patients
App SismIA: Sistema integrado de alerta sísmica temprana y asistencia a partir de inteligencia artificial, proyecto con enfoque adaptativo
No full textThis scientific article presents the development of SismIA, an innovative application designed to enhance seismic warning systems in Mexico City. SismIA is at the forefront of new technologies, as it makes use of artificial intelligence to assist its users when they receive the seismic patterns provided by SASMEX, the city's seismic warning system par excellence. This is done to contribute to the safety of citizens and their preparedness for seismic events, in the same way that it becomes a challenge for project management with an agile approach as it is a natural phenomenon. Keywords—Application, Seismic warning systems, Mexico City, new technologies, artificial intelligence, safety, seismic event, project management, agile approach, natural phenomeno
Time Series Water Body Analysis Through Planet Satellite Imagery: A Coastal Urban Case Study
No full textMany water bodies play a crucial role as receiver of several urban basins within the water system of a city, these urban basins often face challenges of pollution and reduction in water flow, such as, the case of the Juan Angola channel in the city of Cartagena, Colombia. Current remote sensing strategies using Landsat and Sentinel-2 satellite imagery, lack the necessary spatial resolution to adequately study such as water bodies. In contrast, higher spatial resolution data, such as the PlanetScope one, allows for better spatial and temporal details. Nevertheless, PlanetScope does not count with the same spectral resolution as Landsat and Sentinel-2, requiring of further processings to extract relevant information. In this paper, we used PlanetScope satellite images, processed through computer vision techniques, to analyze the evolution of the Juan Angola channel, Laguna del Cabrero and Chambac´u over time. Our approach involved extracting water areas from PlanetScope images and comparing these over different periods. Preliminary findings revealed noticeable variations in the area of the channel due to factors such as rainfall and possible illegal human invasion, as well as, the increment in level of contamination observed by means of the Normalized Difference Turbidity Index (NDTI). The images used from PlanetScope offered a more detailed time-series analysis of different hydrographic areas, which is particularly pertinent in the Juan Angola channel