Ingeniería y Competitividad

Simulation of the absorber layer thickness variation in SnS solar cells using Matlab

2024-08-28T09:09:48-05:00

The study of thin-film solar cells based on tin sulphide is becoming increasingly relevant due to its advantages over similar technologies, such as its low cost, toxicity, and the fact that its constituent elements are more abundant in the earth's crust; besides, they could be made by thigh vacuum techniques like thermal spraying, sputtering, co-evaporation, or thermal evaporation. On the other hand, Simulations allow modelling of the behaviour of solar cells to understand the processes and improve the device's efficiency. Therefore, in this work, the simulation process is carried out using mathematical models that represent the physical behaviour of the solar cell made of heterojunction of several thin films with ZnO/ZnS/SnS configuration. Two radiation models were evaluated, one using a theoretical equation and the other with data from the incident radiation. Until today, different simulations of solar cells have been carried out mainly using a Solar Cell Capacitance Simulator (SCAPS); however, this research was developed using MATLAB due to its performance and efficiency. The optimal thickness of the absorbent layer was established from the results obtained for open circuit voltage (V_oc), short circuit current density (J_sc), fill factor and conversion efficiency (n).

Amorphous silica production from Colombian rice husk: demonstration in scaled-up process Products

2024-11-13T15:25:44-05:00

Introduction: the agroindustry generates significant waste, posing environmental, health, and economic challenges. Among these, rice husk, a byproduct of the food industry, stands out due to its potential as a source of silicon. Due to its silicon content, rice husk offers a unique opportunity for sustainable energy production and the extraction of high-value products, such as amorphous silicon dioxide (SiO2). However, optimizing processes for its efficient conversion remains a challenge.
Objective: the aim of this study was to optimize the nitric acid concentration for the pretreatment of Colombian rice husk in order to produce high-purity amorphous SiO2 and demonstrate the feasibility of scaling up the process.
Methods: a two-stage process was developed, which involved treating rice husk with nitric acid, followed by calcination at 620 °C. The nitric acid concentration was optimized to achieve the highest SiO2 purity. Material characterization was performed using thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray fluorescence (XRF), and nitrogen adsorption-desorption. To assess the scalability of the process, the treatment was replicated on a larger scale using the optimized acid concentration.
Results: the optimized process using a nitric acid concentration of 0.2 M yielded amorphous SiO2 with a purity of 94.9% and a surface area of 298 m²/g. When scaled up, the process achieved SiO2 with a purity of 95.5%, confirming the feasibility of the methodology for industrial applications.
Conclusions: the treatment of rice husk with nitric acid followed by calcination proves to be an effective and scalable approach for producing high-purity amorphous SiO2. This process not only holds potential for industrial applications but also provides a sustainable solution for valorizing agroindustrial waste, contributing to the circular economy.

Integration of the steam approach in teaching linear algebra to engineering students

2024-12-05T10:26:16-05:00

Introduction: this study examines the integration of the STEAM (Science, Technology, Engineering, Arts, and Mathematics) approach and technological tools in teaching linear algebra, a fundamental subject in engineering education. Since a deep understanding of algebraic concepts is crucial for academic and professional success in engineering, the research explores how these innovative methodologies can enhance learning in this field.
Objetive: the aim of this study was to assess the effectiveness of integrating the STEAM approach and technological tools in teaching linear algebra to engineering students, with the goal of improving their academic performance and satisfaction with the implemented teaching strategies.
Methodology: a sequential explanatory mixed-methods design was used, combining standardized summative assessments (α = 0.85) and open-ended evaluations, along with qualitative data from the Course Experience Questionnaire (CEQ, α = 0.92). The participants were 29 engineering students selected through purposive sampling.
Results: the results revealed a significant improvement in students’ academic performance, with a statistically significant difference (p < 0.01) and a large effect size (d = 0.78). Additionally, the participants expressed high satisfaction with the teaching strategies implemented, according to the course experience questionnaire results.
Conclusions: the integration of the STEAM approach and technological tools in teaching linear algebra shows promise in improving both conceptual understanding and practical application of the concepts in engineering contexts. The findings suggest that these methodologies can be an effective means of enhancing both academic performance and student satisfaction in technical disciplines.

Wavelet Analysis of a High Impedance Fault Modeled as a Stochastic Hybrid SystemProducts

2024-12-05T10:26:14-05:00

Introduction: electrical networks are sensitive to faults, and among the most common types, one of the most difficult to detect is the High Impedance Fault (HIF). This type of fault can go unnoticed due to its particular characteristics, such as the ground resistance and voltage drops in the electric arc.
Objective: to propose a stochastic hybrid model for simulating high impedance faults, using the Ornstein-Uhlenbeck process to describe the random nature of these faults. The model focuses on key HIF parameters: ground resistance and voltage drops in the electric arc.
Methodology: the Ornstein-Uhlenbeck process is used to model the randomness of high impedance faults. Simulations are conducted to compare the numerical results with experimental signals reported in the literature. Additionally, both continuous and discrete wavelet transforms are applied to the line current signal to analyze fault characteristics.
Results: the simulations show a qualitative similarity between the numerical results obtained and the experimental signals available in the literature. Both continuous and discrete wavelet transforms reveal typical features of high impedance faults, validating the effectiveness of the proposed model.
Conclusions: the proposed stochastic hybrid model for high impedance faults is effective in simulating this type of fault, and wavelet transform analyses demonstrate its ability to identify distinctive characteristics of HIFs, which can improve the detection and diagnosis of these faults in electrical networks.

Thermal Integration in Sugar Production Using Pinch Analysis

2024-10-15T14:14:26-05:00

Objective: the objective of this study is to conceptualize a network of heat exchangers designed to minimize energy waste and enhance the overall efficiency of the sugar production system.
Methods: a systematic approach was adopted to analyze energy flows within the plant, identifying key areas for improvement, particularly in heating and evaporation processes. Heat accumulations in cascades and graphical analyses of composite curves were developed using specialized software to optimize heat exchange.
Results: the results indicate a significant potential for energy savings, reducing the consumption of cooling and heating utilities in the plant by 7% and 30%, respectively. The developed computational tool allows for energy integration from simple processes to those with hundreds of streams. The pinch technology concept estimated an annual total savings of $464,850.08 in the selected process.
Conclusion: this study demonstrates that thermal integration through pinch analysis not only improves energy efficiency in the sugar industry but also contributes to a considerable reduction in operational costs and environmental impact, providing a valuable tool for the industry’s sustainability and competitiveness.

Socioeconomic study of cacao production units in San Vicente de Chucurí

2024-11-13T15:25:41-05:00

Introduction: cacao cultivation (Theobroma cacao L.) is one of Colombia’s main agricultural products, with particular importance in the department of Santander, which accounts for the majority of the national production. However, cacao production units in the rural areas of this department face various challenges, such as lack of technical and financial support, poor infrastructure, and adverse climatic conditions, which negatively affect their competitiveness and sustainability. This study aims to comprehensively characterize these cacao production units in terms of their economic, social, environmental, and institutional dimensions, in order to provide a broader understanding of their operating conditions.
Objectives: the main objective of this research is to characterize cacao production units in the rural areas of Santander, specifically those belonging to the Asociación Municipal para la Promoción Integral de la Mujer Rural (APRIMUJER). Specific objectives include: Analyzing the socio-economic and productive characteristics of the cacao units. Identifying the main challenges faced by the women producers in terms of technical assistance, financing, and infrastructure, and proposing recommendations to improve the sustainability and competitiveness of these production units.
Methodology: the study was conducted with a quantitative approach, non-experimental and cross-sectional in design, with descriptive and explanatory scope. A non-probabilistic intentional cluster sampling method was used, selecting 30 cacao production units from APRIMUJER. Data was collected using a semi-structured questionnaire, which provided information on the economic, social, and productive conditions of the cacao units.
Results: the results show that the production units are entirely composed of women, with an average age of 46.86 years. 63% of the producers have cacao plantations ranging from 1 to 3 hectares, with an average annual yield of 548 kg/ha of dry beans. Despite these relatively good productivity levels, 90% of the producers earn less than a minimum monthly wage. Additionally, 83% face challenges related to limited technical assistance and pest and disease management. These findings highlight the difficulties faced by female cacao producers in improving their productivity and competitiveness in a resource-limited environment.
Conclusions: the study underscores the urgent need for comprehensive support programs targeting female cacao producers, particularly to improve access to specialized training and establish financing routes to invest in infrastructure and pest management. The inclusion of academic, governmental, and private stakeholders as part of a governance strategy could be crucial for the sustainable development of production units and the improvement of socio-familial cohesion within rural associations. These efforts would contribute to strengthening the competitiveness of cacao production units and improving the socio-economic conditions of rural women in the region.

Hybrid Optimization Algorithm Based on Whale Optimization and Fuzzy Logic for Magnetorheological Dampers

2024-10-01T08:03:52-05:00

Introduction: to mitigate vibrations in structures subjected to dynamic loads, magnetorheological (MR) dampers have been studied as an effective solution to reduce the forces and deformations caused by these loads. Due to their highly nonlinear behavior, it is necessary to implement nonlinear control algorithms to achieve optimal control forces that minimize the response of the structures.

Objective: this study aims to reduce the response of a real building located in Medellín, Colombia, equipped with MR dampers. The goal is to optimize a fuzzy logic controller, using Gaussian membership functions that will be enhanced through the whale optimization algorithm, to find the appropriate voltage to be applied to the damper and generate optimal damping forces.

Results: the results show that the implementation of a set of MR dampers, controlled by fuzzy logic and optimized with the whale algorithm, significantly reduces the structural response to seismic loads. Reductions of 68% in displacement, 42% in velocity, 12% in acceleration, 42% in interstory drift, and 75% in the RMS value of displacement were observed compared to a system without control.

Conclusions: the application of the proposed controller proves to be effective in enhancing the performance of magnetorheological dampers in reducing the structural response to dynamic loads, highlighting its potential in the design of control systems for vibration mitigation in buildings.

A methodology for hydrologic design of porous-concrete pavements

2024-11-13T15:25:49-05:00

Introduction: porous concrete pavements represent an effective solution for reducing surface runoff in urban environments, contributing to the sustainable development of cities. These pavements allow water infiltration, which is crucial to mitigate the effects of urbanization, such as flooding. However, the infiltration capacity of the pavement depends not only on the porous concrete wearing course but also on the characteristics of the granular base and the natural soil subgrade, requiring an integrated analysis of the layered system.
Objectives: the main objective of this study is to present a simplified methodology based on the Horton model to define the hydrologically necessary thickness of the granular base and simulate the movement of water in the porous pavement system. This methodology aims to facilitate the design and analysis of permeable pavements in urban settings.
Methodology: the methodology is based on the Horton model, which is used to simulate water infiltration into soils. The necessary thickness of the granular base is defined through a simplified approach that takes into account both the characteristics of the pavement and the underlying layers. Subsequently, a simulation of water movement within the system is performed to evaluate the effectiveness of the proposed design. To illustrate its application, a typical hydrological design case is presented.
Results: the application of the proposed methodology to a typical design case allows for the determination of the appropriate thickness of the granular base required to ensure efficient water infiltration. The results show that the model can be used as an effective tool to calculate and simulate water behavior in porous concrete pavement systems.
Conclusions: the simplified method presented is useful for engineers involved in the hydrological design of permeable pavements, as it provides a quick and effective way to calculate the thickness of the granular base and simulate water movement. Additionally, this methodology can be of great value in academic training in urban drainage, both at the undergraduate and graduate levels.

Adsorption isotherms for copper and chrome removal from landfill leachate

2024-10-15T14:12:44-05:00

Introduction: the treatment of leachates containing heavy metals, such as copper (Cu) and lead (Pb), is crucial as their levels often exceed permissible limits established by regulations. This study focuses on evaluating the efficiency of treating these metals using adsorption with processed coffee pulp.
Objective: the objective of this study is to determine the removal rates and adsorption capacity of copper and lead in landfill leachates.
Methods: adsorption isotherms were conducted in individual solutions using the Langmuir and Freundlich models. A 2^3 experimental design and response surface analysis were applied to evaluate the variables. Additionally, thermodynamic parameters were determined to understand the type of adsorption.
Results: the results indicate that the Langmuir model best fits the adsorption of copper and lead. The maximum adsorption capacities for copper at doses of 1.3 and 5 g of adsorbent material were 0.29, 0.12, and 0.59 mg/g, while for lead, they were 0.05, 0.02, and 0.02 mg/g. The adsorption rates for copper were 65.3%, 71.0%, and 69.4%, and for lead, they were 30.30%, 13.80%, and 25.40% at the respective doses.
Conclusion: the thermodynamic parameters suggest that the adsorption mechanism is chemical in nature, supporting the effectiveness of processed coffee pulp as an adsorbent material for the removal of heavy metals in leachates.

Validation of the Intelligence Technique in the detection of cyber attacks

2024-08-28T09:09:52-05:00

This article presents the process carried out to evaluate the most suitable intelligence technique for the identification of malicious traffic in order to minimize the risk of a cyberattack. This was accomplished through four phases using an action research methodology articulated to a systematic literature review, and through proposed scenarios that allowed for the validation of this approach.

Impact of Construction and Demolition Waste Concrete on the Safety and Durability of Two-Story Houses

2024-08-28T11:50:36-05:00

Introduction: the construction industry faces a significant challenge in using construction and demolition waste (CDW) as coarse aggregate in structural concrete. The incorporation of these recycled materials can impact the safety and durability of structures, highlighting the need to investigate their viability in concrete mixtures.
Objective: the objective of this study is to evaluate the safety and durability of concrete modified with CDW through a comparative structural analysis. The aim is to establish the relationship between compressive strength indices and steel percentages based on different proportions of CDW in the mix.
Methods: compression tests were conducted based on a conventional concrete mix design according to the ACI-6318 method. Variations in the water/cement (w/c) ratio were made, and the coarse aggregate (¾”) was partially replaced with CDW in percentages of 5%, 10%, and 15%. Different types of collected bricks (#4, structural, and paver) were used, resulting in a total of 102 specimens evaluated at 7, 14, and 28 days post-molding.
Results: the results indicate an effective relationship that meets the minimum requirements of the Colombian Seismic Resistant Construction Rule (NSR-10 - Title B). The comparison of a two-story house model shows that using #4 brick type at percentages below 10% provides significant benefits in terms of structural safety and durability.
Conclusion: it is concluded that the use of construction and demolition waste as aggregate in concrete can be an effective strategy to enhance sustainability in construction without compromising the safety or durability of structures, especially when appropriate bricks are used in controlled proportions.

Use of mining effluents for the production of algal-based colorants

2024-08-28T09:09:39-05:00

In this research, a mining effluent was used to produce microalgal and cyanobacterial biomass to obtain red (carotenoids) and blue pigments (phycocyanin). Two strains were isolated from a hydrothermal source in Norte de Santander and grown in mining wastewater mixed with 50% BG-11 medium for the Osci_UFPS01 cyanobacterium and 50% with Bold Basal medium for the Chlo_UFPS01 microalgae. A carbon, nitrogen, and phosphorus experiment design was developed, and subsequent response surface analysis (RSM) was used to determine the optimal operating conditions for the formation of the products of interest. A notable decrease in pigment production was observed compared to that in the controls without mining wastewater. Overall, 45% of phycocyanin (C PC) per unit dry weight (DW) and 1,129% (w/w) of carotenoids were obtained in the cultures with a mining wastewater mixture in the final optimization processes.

Environmental Impacts and Health Effects in the Surroundings of the Río Hondo, Cauca

2024-10-04T12:36:44-05:00

Introduction: the community of the El Salvador village lacks a sewage system, which leads to the direct discharge of untreated wastewater into the Río Hondo. The inhabitants are unaware of the environmental impacts and health risks associated with this practice.
Objective: the purpose of this study was to identify environmental impacts and health symptoms in the area surrounding the Río Hondo that crosses through the village.
Methods: two methodological phases were established for data collection. In the first phase, environmental aspects related to the water quality of the Río Hondo were identified using a checklist and a Leopold matrix. The second phase involved determining health symptoms related to environmental factors in the area, for which a survey was conducted with a sample population of 60 people.
Results: an 87.5% non-compliance rate was observed compared to a 12.5% compliance rate regarding environmental factors, indicating a higher percentage of environmental impact concerning water quality, land use, biodiversity, pollution sources, regulations, and human health impacts. Poor waste disposal and the lack of sewage management exacerbate the environmental and health issues faced by the inhabitants of the area. The most frequently reported symptoms in the survey were stomach pain and intestinal infections (46.7%), followed by dengue (43.3%), chikungunya (3.3%), and malaria (3.3%).
Conclusion: the absence of an adequate sewage system and improper waste disposal significantly contribute to environmental and health problems in the El Salvador village community. It is crucial to implement environmental management and public health measures to mitigate these adverse effects.

Use of Model-Driven Architecture in the storage of PM 2.5 and public health data

2024-09-12T10:43:32-05:00

Introduction: This paper addresses the storage of data on health events and PM2.5 particles in the city of Medellín, Colombia. The consolidation of data from heterogeneous sources poses a significant challenge in this context.
Objective: The aim of this study is to propose a metamodel that facilitates the integration and storage of these data using a model-based approach.
Methods: A modeled approach was developed to identify common aspects for building a data warehouse. An abstraction layer was defined over the conceptual models of particulate matter and health events.
Results: The main result was the creation of a data warehouse prototype that allows for the efficient consolidation of data on PM2.5 and health events. This prototype demonstrates the effectiveness of the proposed approach in data integration.
Conclusion: It is concluded that using a model-based approach strengthens decision-making in public health policies and quality management strategies in the healthcare sector.

Transformation of Organic Cacao (Theobroma cacao) Husk into Commercial

2024-10-01T08:03:49-05:00

Introduction: agroindustrial wastes can be transformed to mitigate the negative impacts associated with their disposal. In cocoa production, cocoa pod husk (CPH) constitutes between 67% and 76% of the total cocoa weight. This study focuses on the potential of CPH as a valuable resource for producing activated carbon, cellulose, and potassium hydroxide (KOH)..
Objective: The objective of this research was to characterize and transform the CPH obtained from an organic crop in San Bernardo-Ibagué (Colombia) into activated carbon, cellulose, and KOH.
Methods: activated carbon was produced through chemical activation using KOH, with a specific procedure for characterizing the obtained product through thermal analysis (TGA) and nitrogen adsorption and desorption isotherms. For cellulose extraction, an alkaline treatment with 2% w/w NaOH was followed by a bleaching process with 2.5% w/w sodium hypochlorite. KOH was obtained by first extracting potassium carbonate and then causticizing it.
Results: activated carbon (AC) was produced with a yield of 25.6%, exhibiting a surface area of 468 m²/g, a mean pore diameter of 10.8 nm, and a total pore volume of 0.228 cm³/g, with 60% fixed carbon, 27% volatile material, 6% ash, and 6% moisture.
Conclusions: the transformation of cocoa pod husk into activated carbon, cellulose, and KOH provides a sustainable approach to managing agroindustrial waste, generating valuable products with significant potential for various applications. The results obtained demonstrate the feasibility of utilizing CPH as a resource in agroindustrial processes.

Fourier analysis for detecting vegetation in hyperspectral images

2024-10-09T16:14:00-05:00

Introduction: hyperspectral images, unlike conventional images, are composed of numerous channels that provide detailed information about the spectral signatures of objects. This allows for the identification of the materials that make them up, and given their potential for detecting environmental changes, identifying vegetation in urban settings using effective computational methods becomes relevant.
Objective: the objective of this research is to propose a computational method based on Fourier analysis for detecting vegetation in hyperspectral images.
Methods: the research was developed in four methodological phases: selection of technologies, acquisition of the characteristic vegetation pixel, determination of phase similarity between the characteristic pixel and vegetation and non-vegetation pixels, validation of the method on a test hyperspectral image. A method was implemented using the spectral and numpy libraries in Python.
Results: the Fourier analysis yielded an average phase similarity of 89.89% and a minimum similarity of 64.54% between the characteristic vegetation pixel and 100 training vegetation pixels. For non-vegetation pixels, the average phase similarity was 42.19%, with a maximum similarity of 63.98%. These results indicate that the proposed method successfully differentiates between vegetation and non-vegetation pixels.
Conclusion: the results demonstrate that the Fourier-based method can accurately identify vegetation areas in hyperspectral images, showing non-overlapping phase similarities between vegetation and non-vegetation. This validates the effectiveness of the proposed approach in detecting vegetation in urban environments.

Retraction Notice to: Integration of the steam approach in teaching linear algebra to engineering students

2024-12-04T15:03:16-05:00

Green hydrogen state of the art review of generation technologies for the decarbonisation of the energy sector

2024-08-28T09:09:42-05:00

The growing concern about environmental problems and the depletion of fossil fuels has generated an interest in the development of technologies that allow us to produce electricity without polluting the environment. In recent decades, hydrogen has become the main candidate to replace fossil fuels, with the possibility of being used as a primary fuel to be burned in combustion engines, or as an energy vector for the production of energy by means of fuel cells, making it an attractive fuel due to its high energy density and the fact that it does not emit any type of pollution. At present, hydrogen is not produced for energy purposes, but for industrial purposes, so the purpose of this article is to learn about the predominant forms of hydrogen production, which use fossil fuels as raw materials, and to study the new technologies developed to obtain decarbonised hydrogen for the energy sector, researching known technologies such as electrolysis, comparing the functioning of the existing types of electrolysis and describing other novel forms such as those that make up the production of biological hydrogen or bio-hydrogen, analysing different research with the aim of presenting the results in fermentative methods, the use of microalgae and the microbial electrolysis cell, explaining the main results in the production of hydrogen for the energy sector, as well as the main applications in the production of hydrogen from fossil fuels and the use of microalgae.

A Systematic review of improvement methodologies for optimization in production management in the restaurant sector

2024-08-28T09:09:34-05:00

The objective of this research was to identify methodologies for optimization in production management in restaurants. The systematic literature review method was applied using the most relevant metasearch engines: ScienceDirect, Scopus and Web of Science; The determination of the search formula continued, reading and analyzing the results to identify improvement methods; Finally, the synthesis of the most relevant and most innovative articles was carried out. The research resulted in 46 articles of various types of methodologies that optimize production management in all its aspects in restaurants.

User Experience (UX) Evaluation in Gamified Processes: a bibliographic Review

2024-10-04T12:36:46-05:00

Introduction: in the context of technology design, the measurement and understanding of user experience (UX) have gained crucial relevance. This aspect addresses the pressing need to understand in detail how users interact with and experience technological artifacts. This review focuses on user experience in the design of gamified processes and products, considering that despite advances in inclusivity and accessibility, some individuals still cannot access the benefits of technological tools.
Objective: the objective of this documentary review is to identify and analyze the techniques and methods employed to evaluate user experience in the context of gamified processes and products.
Methods: a structured literature review was utilized to gather information on the techniques and metrics used in UX evaluation. A diversity of indicators was examined, ranging from usability to more subjective aspects such as aesthetics, as well as the evaluation approaches applied in previous studies.
Results: the findings revealed a wide variety of indicators and metrics used in the evaluation of UX in technological environments. Both the differences and similarities in evaluation practices were highlighted. The review underscored the complexity of user experience and the importance of considering not only usability but also broader aspects, especially in the realm of gamification.
Conclusions: is concluded that adopting multidisciplinary approaches and using validated tools is essential to achieve a more comprehensive and applicable understanding of gamified products or processes. This will enhance understanding at the intersection of technology and gamification.