Universidad Tecnológica de Bolívar
Repositorio UTB (Universidad Tecnológica de Bolívar)Not a member yet
11796 research outputs found
Sort by
Fire Scars Mapping Over Brazilian Amazon Forest by Exploiting Sentinel-2 Data and Deep Learning
No full textWildfires in the Brazilian Amazon have raised significant concerns owing to the environmental, social, and global impacts associated with these events. They have led to habitat loss for various species and release of substantial amounts of carbon dioxide into the atmosphere. Thereby contributing to climate change and deterioration of air quality due to pollutants emission. The integration of advanced technologies, including high-spatial resolution satellite data and image processing algorithms, enables a more precise and comprehensive understanding of the wildfire scenario. This research introduces a model based on deep learning that can be applied over Sentinel-2 images to reliably detect fire scars with an accuracy above 90% (92% on training data and 82% on validation data). A SpectrumNet convolutional neural network was employed, incorporating features extracted from spectral bands at 10m and 20m
Enhancing the solar water pumping efficiency through Beta MPPT method-controlled drive
No full textThis paper presents an innovative approach to achieve efficient solar water pumping through the integration of a Photovoltaic (PV) array and a Brushless Direct Current (BLDC) motor water pumping system. The system incorporates a Voltage Source Converter (VSC) with six switches, utilized to facilitate commutation. The inherent solar radiation is harnessed by the PV array, capitalizing on its renewable nature to generate electricity. By dynamically adjusting the switching states of the six VSC switches, the speed of the BLDC motor is modulated in response to the varying levels of available solar radiation. The BLDC motor's hall sensor signals play a crucial for determining the rotor's position and they are employed to generate precise commutation signals. The control strategy integrates the Incremental Conductance (INC) Maximum Power Point Tracking (MPPT) algorithm, which initially governs the commutation signals. To enhance adaptability to rapidly changing solar irradiation conditions, the control strategy dynamically updates the commutation signals using the innovative Beta MPPT algorithm. To assess the efficiency of the proposed control strategy, a comprehensive comparison between the INC and Beta MPPT algorithms is conducted using MATLAB Simulink. The performance of the BLDC motor under these algorithms was evaluated in terms of its ability to optimize energy extraction. The graphical analysis of these algorithms, considering the temporal aspect, substantiates the identification of the superior MPPT algorithm for BLDC motor control in solar water pumping applications. This study contributes to the advancement of solar water pumping systems by introducing a novel control approach that combines PV array utilization, VSC-based commutation, and a dual-step MPPT algorithm. The results demonstrate the effectiveness of the Beta MPPT algorithm by enabling the system to respond promptly to fluctuating solar irradiation conditions, thereby enhancing the overall efficiency of the solar water pumping process
Optimization of combustion characteristics on a diesel engine fueled by Mahua biodiesel with dispersion of graphene oxide and zinc oxide nanoparticles as additives using design of experiment
No full textThe current research investigates the effects of adding metallic graphene oxide (GO) and non-metallic zinc oxide (ZnO) nanoparticles to Mahua biodiesel blend (B20) on the combustion parameters of a diesel engine. GO and ZnO nanoparticles were utilized at a concentration of 75 mg/L, combined with a 1:1 mixture of the surfactant CTAB and the dispersant TWEEN 80. When nanoparticles were introduced to blended biofuel, combustion parameters such as cumulative heart rate, mean gas temperature, mass percent burnt, and rise of pressure increase (RoPR) greatly improved at higher injection pressures. When compared to clean diesel, utilizing B20+ZnO Nanoparticles+ NIS dispersant at 250 bar resulted in 6%, 15%, 7%, and 7.6% improvements in CHRR, MGT, MFB, and RoPR, respectively. The correlation coefficient (R2) for B20+ZnO NPs+ NIS (1:1) for CHRR, MGT, MFB and RoPR is 0.975, 0.978, 0.966 and 0.9883 when compared to GO nanoparticle inclusions, considering it as optimum combination and an efficient fuel. When compared to other fuel samples, the CHRR, MGT, MFB and RoPR for B20+ZnO NPs+ NIS are 2.484%, 3.2%, 2.6% and 1.25% higher, respectively, according to a statistical analysis conducted by design expert
Sistematización de la Experiencia Lograda con El Proyecto de Semillero de Investigación
No full textEl propósito de este estudio fue sistematizar la experiencia del semillero de investigación “Lancero Romeristas” en la Institución Etnoeducativa Oficial Pedro Romero de la ciudad de Cartagena, con el fin de extraer lecciones aprendidas del proceso que permita fortalecer el programa y replicarlo en otras instituciones educativas con dinámicas y necesidades similares. En el estudio se estableció un enfoque cualitativo de investigación que implicó la documentación de la experiencia formativa llevada a cabo y la recolección de información primaria, con la participación de los miembros de la comunidad educativa. Se realizaron grupos focales y entrevistas involucrando directamente a las personas con mayor experiencia en el desarrollo del semillero (experiencia). En los resultados se puede destacar que los estudiantes que han participado en el semillero demuestran un conocimiento profundo de su cultura y del territorio local, explorando y valorando sus tradiciones, costumbres e historia. De igual forma, los docentes participantes del semillero han apropiado nuevas metodologías de enseñanza. Así como también, los directivos afianzaron la gestión de sus proyectos. Entre las principales lecciones se destaca la relevancia de utilizar herramientas tecnológicas y una segunda lengua para facilitar el trabajo colaborativo entre los estudiantes
Creatividad y gestión del conocimiento: Herramientas para la creación de valor empresarial
No full textLa gestión del conocimiento abarca una serie de procesos y prácticas diseñadas para identificar, capturar, almacenar, compartir y aplicar el conocimiento de manera efectiva en toda la organización. Dicho de otra forma, se aprovecha el conocimiento presente en las organizaciones para mejorar su capacidad de adaptación, innovación y rendimiento. Como una parte de la estrategia empresarial contemporánea, la gestión del conocimiento se ha afianzado como una herramienta vital para enfrentar los desafíos que impone un mundo caracterizado por la rápida evolución tecnológica y la intensa competencia global. En un entorno con estas características, con la volatilidad y la incertidumbre a la
orden del día, estrategias basadas en la gestión del conocimiento —combinadas con la innovación— son clave en la creación de valor empresarial de largo plazo
The rights of animals as sentient beings in Colombia
No full textEn Colombia, las normas referentes a los animales se crearon bajo la Constitución Política colombiana de 1886 y los consideraban como objetos semovientes desde principios liberales clásicos. Así, quien ostentara derechos reales sobre los animales, podría disponer de ellos sin más límite que los derechos de otras personas. Sin embargo, la Constitución Política colombiana de 1991 propende por interpretaciones auténticas adscritas al antiformalismo, las cuales han evidenciado que los animales no son meros objetos, sino que se catalogan como seres sintientes. Esta nueva categoría conlleva mandatos de bienestar animal que deben ser cumplidos por los seres humanos y en caso de incumplimiento tienen sanciones penales. De ahí se desprende la posibilidad que los animales en calidad de seres sintientes gozan de derechos constitucionales de obligatoria observancia y organizados en generaciones regulatorias que requieren de una posterior reglamentación.In Colombia, the regulations regarding animals were created under the Colombian Political Constitution of 1886 and considered them as objects related to classical liberal principles. Thus, whoever held real rights over animals could dispose of them with no more limits than the rights of other people. However, the Colombian Political Constitu-tion of 1991 favors authentic interpretations ascribed to anti-formalism, which have shown that animals are not mere objects, but are classified as sentient beings. This new category carries animal welfare mandates that must be complied with by humans and in case of non-compliance they have criminal sanctions. From this arises the possibility that animals as sentient beings enjoy constitutional rights of mandatory observance and or-ganized in regulatory generations that require subsequent regulation.1. Introducción.
2. El contexto constitucional de los derechos en relación con los animales.
3. Los seres sintientes desde los derechos constitucionales.
4. Conclusiones. Referencias bibliográficasAnálisis de políticas públicasNO APLIC
Data augmentation via warping transforms for modeling natural variability in the corneal endothelium enhances semi-supervised segmentation
No full textImage segmentation of the corneal endothelium with deep convolutional neural networks (CNN) is challenging due to the scarcity of expert-annotated data. This work proposes a data augmentation technique via warping to enhance the performance of semi-supervised training of CNNs for accurate segmentation. We use a unique augmentation process for images and masks involving keypoint extraction, Delaunay triangulation, local affine transformations, and mask refinement. This approach accurately captures the natural variability of the corneal endothelium, enriching the dataset with realistic and diverse images. The proposed method achieved an increase in the mean intersection over union (mIoU) and Dice coefficient (DC) metrics of 17.2% and 4.8% respectively, for the segmentation task in corneal endothelial images on multiple CNN architectures. Our data augmentation strategy successfully models the natural variability in corneal endothelial images, thereby enhancing the performance and generalization capabilities of semi-supervised CNNs in medical image cell segmentation tasks.Minciencia
Computational study on the inhibition mechanisms of the ziegler-natta catalyst in the propylene polymerization process: part 1 effects of acetylene and methylacetylene
No full textAcetylene and methylacetylene are impurities commonly found in the raw materials used for the production of polymers such as polypropylene and polyethylene. Experimental evidence indicates that both acetylene and methylacetylene can decrease the productivity of the Ziegler-Natta catalyst and alter the properties of the resulting polymer. However, there is still a lack of understanding regarding the mechanisms through which these substances affect this process. Therefore, elucidating these mechanisms is crucial to develop effective solutions to this problem. In this study, the inhibition mechanisms of the Ziegler-Natta catalyst by acetylene and methylacetylene are presented and compared with the incorporation of the first propylene monomer (chain initiation) to elucidate experimental effects. The Density Functional Theory (DFT) method was used, along with the B3LYP-D3 functional and the 6-311++G(d,p) basis set. The recorded adsorption energies were −11.10, −13.99, and −0.31 kcal mol−1, while the activation energies were 1.53, 2.83, and 28.36 kcal mol−1 for acetylene, methylacetylene, and propylene, respectively. The determined rate constants were 4.68 × 1011, 5.29 × 1011, and 2.3 × 10−8 M−1 s−1 for acetylene, methylacetylene, and propylene, respectively. Based on these values, it is concluded that inhibition reactions are more feasible than propylene insertion only if an ethylene molecule has not been previously adsorbed, as such an event reinforces propylene adsorption.Universidad Tecnológica de Bolivar, Universidad de Cartagena, Universidad de la Cost
Misreading as a jus theory-creating possibility in a globalized context from a transnational perspective
No full textEn la actualidad, el contexto global cuenta con un conjunto de teorías y escuelas del derecho provenientes de diferentes contextos. Algunos de esos contextos se consideran como sitios de producción teórica y otros como sitios de recepción, por lo cual hay quienes proponen iusteorías y otros que las acogen como consecuencia de un proceso trasnacional. Ese proceso de interacción entre diferentes sitios se conoce como el trasplante iusteórico, el cual plantea la posibilidad de enfrentar elementos textuales, extratextuales y metatextuales de los diferentes sitios involucrados en el proceso. Como consecuencia de esta interacción, los sitios de recepción generan mutaciones de las teorías construidas en los sitios de producción y esto es denominado como el misreading. Aunque para los productores la mutación tiene un alcance negativo, para los receptores puede ser en sí misma una nueva teoría.Currently, the global context has a set of theories and schools of law from different contexts. Some of these contexts are considered as theoretical production sites and others as reception sites, for which reason there are those who propose JUS theories and others who accept them as a consequence of a transnational process. This process of interaction between different sites is known as the JUS theoric transplant, which raises the possibility of facing textual, extratextual and metatextual elements from the different sites involved in the process. As a consequence of this interaction, the reception sites generate mutations of the theories built in the production sites and this is called misreading. Although for the producers the mutation has a negative scope, for the receivers it may be in itself a new theory.Universidad Tecnológica de Bolíva
Advancing energy innovations: Reflections on 2024, prospects for 2025
No full textThis editorial reflects on key points in the energy transition during 2024, including renewable energy growth, advancements in energy storage, and the rise of electric mobility. It also introduces special sections featuring research from the 2023 IEEE Colombian Caribbean and ICARGET Conferences. Looking ahead to 2025, it highlights the transformative roles of artificial intelligence, green hydrogen, and smart cities in shaping a sustainable energy future, reaffirming the journal’s commitment to driving innovation and global energy progress