Heavy metal contamination of soils and ecosystems is an environmental problem that requires urgen... more Heavy metal contamination of soils and ecosystems is an environmental problem that requires urgent attention due to the ecological problems that it generates. Forest species can be used to mitigate contamination because of their potential to bioaccumulate contaminating metals. The objective of this work was to evaluate the bioaccumulator potential of heavy metals in five forest species that live in mining environments in the Ecuadorian Amazon region. The bioconcentration factor for five forest species, such as: Cedrela odorata, Parkia multijuga, Inga edulis, Cecropia ficifolia and Pourouma cecropiifolia, commonly found in the Ecuadorian Amazon was analysed, based on the relationship between the concentration of the heavy metal in leaves and the soil. Atomic absorption spectrometry was used to analyse heavy metals in leaves and soil samples of each plant specie. The results showed that P. cecropiifolia had the highest bioconcentration factor for lead, C. odorata for cadmium and nickel, and I. edulis had the highest potential for iron and aluminium absorption. No correlation was found between the concentration of each element in the soil and the leaves, which shows that the bioaccumulation capacity of the species studied does not depend on the concentration of the element in the soil. This provides relevant information for the inclusion of these species for phytoremediation purposes.
The purpose of this research was to determine the quality of water for bovine consumption on live... more The purpose of this research was to determine the quality of water for bovine consumption on livestock farms in the El Progreso parish - Galapagos by applying a quality index following the Brown methodology proposed by the National Sanitation Foundation of the United States. Information was collected from the livestock farms through a socio-environmental diagnosis of the area, where five localities were considered: San Joaquín, Las Goteras, Cerro Verde, Puerto Chino and El Progreso from which fifteen livestock farms were selected for the respective sampling of the sources. of water. Therefore, nine parameters were considered for the analysis of the respective water sources: pH, TDS, Fecal Coliforms, electrical conductivity, hardness, nitrites, phosphates, temperature and turbidity. Of the total livestock farms monitored, three of them presented a rating of Good quality in a range of 70 to 90, while the remaining farms recorded values with a Medium classification, which are those that recorded AQI values between 51 to 70 according to the criteria established by the NSF. This research highlights the importance of frequently carrying out analyzes of the water sources from which cattle drink to determine the quality of the resource, and also provide technical advice to ranchers in the area on the management and cleaning of the reservoirs.
With the objective of determining the productive components, chemical characterization, digestibi... more With the objective of determining the productive components, chemical characterization, digestibility and energy contribution of the Brachiaria hybrid vc Mulato I at different ages of cuts in both periods of the year. For which a randomized block design with four repetitions was used. It was sampled in plots of 25 m2, to which a uniformity cut was applied 10 cm from the ground, without irrigation or fertilization. The yield of total dry matter, leaves and stems was determined; the length and width of the leaves; the leaf-stem ratio, chemical composition (CP, NDF, ADF, ADL, CC, Si, P, Ca, ash and OM), energy contributions and digestibility. A double classification analysis of variance was applied to each variable studied and the means were compared according to Duncan. Crude protein decreased with age for both periods, showing significant differences between all ages. The best values were shown at 30 days of cutt (9.47 and 10.40 % in the rainy and dry periods respectively), the fiber increased with age with its best values at 75 days with (71.39 and 70.11 % in the rainy periods and little rain), aspects that conditioned the quality with a decrease in digestibility and energy intake. The yield of the plant was affected by the periods of the year, being higher in the rainy period. It is concluded that the increase in regrowth age directly influences the depression of nutritional quality and yield in both periods of the year.
Precision agriculture optimizes crop management by providing accurate data on soil chemical prope... more Precision agriculture optimizes crop management by providing accurate data on soil chemical properties, thereby improving agricultural productivity and sustainability. This study aims to develop models to estimate soil chemical properties, such as pH, electrical conductivity (EC), and organic matter (OM), by analyzing drone-captured RGB images. The methodology included photogrammetric flights with a DJI Phantom 4 Pro drone equipped with a 20 Mpx camera and simultaneous sampling, laboratory analysis and on-site measurements, with Royal Eijkelkamp EC meter set voor grond multiparameter sensors and pH meter set for soil and water. The aerial images were processed with the PIX4Dmapper software, to generate the orthophoto and spectral bands. With the resulting orthophoto of 1.6 cm/pixel, eight spectral indices were calculated, using the spatial analysis tools of ArcGIS software. The in situ results showed an average pH value of 5.83, indicating a slightly acidic soil, and an EC of 1.09 dS/m, suggesting a soil with a low concentration of dissolved salts. Laboratory analyses showed a medium-high content of OM, with an average of 5.19 %. A strong correlation was found between OM and pH_index with coefficients of determination R2=0.55, while moderate correlations were also observed between pH with pH_index and EC with sal_index6 with coefficients of determination R2=-0.39 and R2=0.42 respectively. The aforementioned results allowed the generation of two models for the estimation of these variables from RGB images.
Aircraft operators often modify aircraft configurations, install new equipment, and alter airfram... more Aircraft operators often modify aircraft configurations, install new equipment, and alter airframes to accommodate this equipment, leading to operations in flight envelopes different from original design profile. These modifications necessitate airframe structural assessments, which typically require comprehensive aircraft design data, often unavailable to operators. This study aims to develop and validate a practical method for finite element analysis (FEA) of aircraft structures in the absence of this detailed design data. Focusing on a case study involving structural analysis of an aircraft wing, this study presents assumptions and idealizations used to develop 2.5D finite element (FE) model of the wing. Fidelity of this model is established by comparing FE analysis results with experimental data. Key validation metrics include reaction forces, load distribution at wing-fuselage attachments, and deformation at reference points on the wing under design load. Comparison between FE analysis and experimental results is carried out to substantiates accuracy of these geometric simplifications and idealizations of load-carrying behaviour of structural members. Therefore, practicality of these idealizations in absence of design data is demonstrated. This study offers a novel approach for structural assessments of aircraft without relying on proprietary design data. The validated method enhances capability of aircraft operators to perform effective structural analyses, thereby extending service life of aircraft with continued airworthiness.
Artificial neural networks (ANNs) have become indispensable tools for solving classification task... more Artificial neural networks (ANNs) have become indispensable tools for solving classification tasks across various domains. This systematic literature review explores the landscape of ANN utilization in classification, addressing three key research questions: the types of architectures employed, their accuracy, and the data utilized. The review encompasses 30 studies published between 2019 and 2024, revealing Convolutional Neural Networks (CNNs) as the predominant architecture in image-related tasks, followed by Multilayer Perceptron (MLP) architectures for general classification tasks. Feed Forward Neural Networks (FFNN) exhibited the highest average accuracy with a 97.12%, with specific studies achieving exceptional results across diverse classification tasks. Moreover, the review identifies digitized images as a commonly utilized data source, reflecting the broad applicability of ANNs in tasks such as medical diagnosis and remote sensing. The findings underscore the importance of machine learning approaches, highlight the robustness of ANNs in achieving high accuracy, and suggest avenues for future research to enhance interpretability, efficiency, and generalization capabilities, as well as address challenges related to data quality.
The Intensity-Duration-Frequency (IDF) curves are a way to visualize and represent extreme hydrom... more The Intensity-Duration-Frequency (IDF) curves are a way to visualize and represent extreme hydrometeorological rainfall events. In this article, an analysis of convective rainfall events recorded at the La Piedra Meteorological Station, Villa Clara, Cuba, was conducted. To develop IDF curves, the 2006-2019 time series was analyzed. A partial duration series was generated, including intervals from 20 minutes to 4320 minutes, subjected to an outlier detection process. The series was divided into two categories: one for durations ≤ 720 minutes and another for durations > 720 minutes. The resulting series underwent nonparametric tests to assess their independence, randomness, homogeneity, and seasonality. Subsequently, they were fitted to the Generalized Pareto probability distribution and to a parametric equation of the Montana model, and then the curves were plotted for return periods of 10, 50 and 100. The Montana model led to obtaining correlation coefficients greater than 0.90 compared to the other methods used, significantly improving the quality of the fit in both categories. This research provides information to understand and plan the management of intense climatic phenomena and adequate risk management in an area where such studies are lacking, facilitating access to crucial data essential in the design and execution of hydraulic engineering projects in the region.
Manufacturing companies face demand fluctuations and must deliver the required quantity of parts ... more Manufacturing companies face demand fluctuations and must deliver the required quantity of parts to their customers within the required time; however, companies face different challenges in fulfilling them. One is technological advances, which make it impossible for them to compete with other countries, such as China, due to financial issues. Therefore, manufacturing companies use continuous improvement methodologies to achieve better performance in their processes. Six Sigma and Lean Manufacturing are some of the best-known approaches. This article briefly presents the application of a lean sigma approach oriented to solving problems. This research proposes a methodology based on Lean Sigma that contrasts what different authors currently do: continuous improvement projects that take up to 12 months to produce results and do not solve a problem. This implementation is conducted in a process that manufactures metal parts and fails to deliver them on time to its customers. Using tools such as the Single Minute Exchange of Die (SMED) in a production line, on-time deliveries were increased from 89 % to 96 %; at the same time, the model change times were reduced by approximately 60 %, which is required for the implementation of this methodology for only four weeks, unlike the traditional six-sigma approach that can take up to 12 months to improve the process.1
The research addresses the study of heat exchange between heavy crude oil and the environment dur... more The research addresses the study of heat exchange between heavy crude oil and the environment during surface pumping, specifically of a crude oil with an API gravity of 17.5, under the particular atmospheric conditions of Eastern Ecuador. The main objective of the study is to evaluate the temperature loss in a 50-meter segment of SCH-80 pipe, with a diameter of 4 inches, used for the transportation of heavy crude. This aims to understand how heavy crude loses temperature and to determine the convective coefficient, knowing that the heat loss from the fluid to the environment occurs mainly by convection. This is to determine what the temperature losses will be in longer pipe sections. For this purpose, a methodology using computational fluid dynamics (CFD) simulation was employed, a key tool for predicting the thermal behavior of crude in interaction with the environment. It was determined that the convective coefficient is 52 W/m2.K, and there is a temperature loss of 3.2 K in the 50-meter section. With this data, future research could evaluate potential heating technologies that facilitate the transport of heavy crude oil. This approach would allow for exploring innovative solutions to improve efficiency and effectiveness in managing heavy crude, facing one of the main challenges in its transport: managing its high viscosity.
Environmental pollution from transportation has been a fundamental challenge for humanity through... more Environmental pollution from transportation has been a fundamental challenge for humanity throughout history, with conventional fuels contributing significantly to environmental degradation. This project seeks to suppress pollution and reduce noise generated by motorcycle taxis, whether for personal and/or private use. The main objective of the research work was to implement an electrolyzer in the combustion system of a motorcycle taxi to suppress environmental pollution and reduce noise. Methods included vehicle preparation, electrolyzer installation, battery adjustment, hydrogen generation, emissions measurement, safety, and data collection. As a result, the electrolyzer was implemented in the single-cylinder motorcycle taxi; The noise limit allowed at work in Peru is 85 dB, which is equivalent to 100 % noise at most; When using gasoline, a value of 76.4 dB was obtained, equivalent to 89.88 % noise, and when using hydrogen, a value of 71.7 dB was obtained, equivalent to 84.35 % noise, therefore, the total noise reduction was 4.70 dB (5.53 %) than established. The discussion highlighted that hydrogen is a clean fuel, with zero emissions and only emitting water vapor instead of polluting gases [5]. The conclusion highlights the critical importance of the research, supported by the total reduction of 5.53 % of noise with this new technology and in turn external sources support that using hydrogen produced a smoother and quieter combustion; Regarding the useful life of the engine, due to the cleaner and more efficient combustion, the accumulation of waste was reduced, which benefits reducing the wear of internal components and the need for costly maintenance.
There is evidence of the high use of the neonicotinoid insecticide thiamethoxam, in tropical crop... more There is evidence of the high use of the neonicotinoid insecticide thiamethoxam, in tropical crops, for its effectiveness in the control of soil and plant pests. The objective of this study was to know the residuality and concentration of thiamethoxam in the papaya agroecosystem, in the main papaya fruit producing zone in the central area of the Gulf of Mexico. It was carried out during a papaya growing cycle with watermelon rotation; the taking of samples was according to the technique established by the NOM-AA-103-1988 for leaves and for fruit the NMX-FF-041-1996 by the method of quartering in papaya and watermelon, the samples were analyzed with a HPLC-UV, the data obtained were statistically analyzed by parametric and non-parametric Kruskal-Wallis tests. The presence of thiamethoxam was found in papaya and watermelon cultivation plants, the concentrations in papaya leaves reported a maximum value of 0.29 mg/kg, while for the leaves of the watermelon rotation fruit it was 0.15 mg/kg. In papaya fruit, thiamethoxam concentrations are within a range of 0.24 to 0.32 mg/kg. The concentrations and residuality of thiamethoxam mainly exceed the maximum tolerance and residuality limits of the EFSA and FAO. 1
Passive Optical Networks (PONs) are essential in optical communications to meet the increasing de... more Passive Optical Networks (PONs) are essential in optical communications to meet the increasing demand for network capacity and connected users, ensuring reliable and adaptable connections for data transmissions. These networks also simplify infrastructures and efficiently utilize energy by eliminating the need for active devices. In this context, Ultra-Dense Wavelength Division Multiplexing (UDWDM) is one of the most prominent solutions for data transmission. This technology uses the narrow separation between channels from 25GHz and even as small as 6.25GHz to increase the transmission capacity. This document analyzes the performance of UDWDM considering the transmission of three simultaneous channels in a PON network for which three different scenarios have been considered for the analysis with the following parameters: i) transmission speed from 10 Gbps to 17 Gbps, ii) the distance from 10 km to 20 km and iii) the separation between channels of 15GHz, 20GHz, and 25GHz. The performance metrics for the analyzed scenario are the bit error rate and the eye diagram. To ensure the reception of the transmitted channel, an analysis of raised cosine and Gauss filters is also discussed. Including these filters allows for verifying whether their use enhances the performance of the channels compared to transmission without a filter. This is crucial for understanding how filters can optimize the quality and reliability of data transmission in a PON, which is of great importance in environments where high efficiency and connection quality are required.
In this paper, an assessment of the state of coastal territories of Ecuador monitoring issue is c... more In this paper, an assessment of the state of coastal territories of Ecuador monitoring issue is conducted. The use of an autonomous robotic aerial platform is proposed as a technical solution to enhance the efficiency of remote surveillance missions performed by national security services along coastline. Considering the UAV nonlinear flight dynamics, as well as the missing information of the environment, is designed a UAV hierarchical control structure composed of an adaptive PID based MPC control strategy. The implementation of an adaptive PID based MPC controller leads to significantly improve the UAV optimal trajectory tracking task, as well as satisfy properties such as adaptiveness, self-learning, and capability of handling uncertainties caused by the unpredictable behavior of sea currents and wind loads retaining robust performance features. In this work, the investigation of external disturbances on UAV stabilization and positioning accuracy considers swirling wind flows and short-term wind gusts. These correspond to deterministic and random processes, are mathematically represented as trigonometric functions with random amplitudes determined by the gust coefficients and the wind loading periods of the pulses. The established range is given by a set of several observations of wind loads in the coastal territories of Ecuador. The analyzed data is collected from the database of national meteorological stations. Finally, the simulation process of the perturbed controlled motion of the UAV along a segmented linear trajectory, as well as the data analysis and graphics are carried out in the MATLAB environment.
Within the context of agricultural ecosystems, understanding the nutritional physiology of insect... more Within the context of agricultural ecosystems, understanding the nutritional physiology of insects and their host plant preferences is essential for optimizing pest management strategies and improving crop production. In this study, we conducted an in-depth examination of the nutritional physiology of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in the context of different host plants, specifically wheat varieties, in comparison to maize. Our investigation focused on key parameters, including the Relative Consumption Rate (RCR), Relative Growth Rate (RGR), and Efficiency of Conversion of Ingested food (ECI) of S. frugiperda fed on different wheat varieties including: Dilkash-20, Fakhar-E-Bhakkar-17, Subhani-21, Faisalabad-08, and Akbar-19 in comparison to maize (NK-6654). The results revealed that S. frugiperda displayed a significantly (P < 0.05) higher RCR (8.08 g/g/day), RGR (1.50 g/g/day), and ECI (25.1 %) when feeding on maize, followed by Fakhar-E-Bhakkar-17 (RCR =7.00 g/g/day, RGR =1.24 g/g/day and ECI =21.4 %) and Akbar-19 (RCR = 6.06 g/g/day, RGR = 1.04 g/g/day and ECI =19.7 %) wheat varieties after 1 week of feeding. The lowest values of all these nutritional parameters were recorded on the Dilkash-20 variety (RCR = 2.98 g/g/day, RGR = 0.38 g/g/day, and ECI = 7.94 %). These findings offer valuable insights into the nutritional interactions between S. frugiperda and the host plants, shedding light on potential implications for pest management strategies and crop patterns.
The Internet of Things (IoT) has the potential to revolutionize healthcare by enabling remote pat... more The Internet of Things (IoT) has the potential to revolutionize healthcare by enabling remote patient monitoring, personalized care and disease prevention. In Ecuador, research on IoT in the healthcare field is rapidly expanding. However, there’s a need for a clearer understanding of the current state of this research. This study examines the contributions of Ecuadorian authors in this field through their publications in two globally impactful bibliographic databases. The methodology employed is a systematic review using the PRISMA statement, resulting in a final stage comprising 23 articles. These publications encompass system proposals, prototypes, and reviews with applications in areas such as epidemiology, cardiology and nursing. The recurrent mention of patient information privacy is a challenge in implementing IoT-based healthcare systems. The conclusions emphasize that future work perspectives should address the challenges identified, considering the growing trend of publications from Ecuadorian authors.
This paper introduces the Distributed Utility Function Algorithm (D-AFU) as a notable progression... more This paper introduces the Distributed Utility Function Algorithm (D-AFU) as a notable progression in managing and optimizing network traffic within distributed settings. Based on the utility function principle, D-AFU dynamically adjusts data rate in response to ever-changing network demands, with optimal performance and a higher user experience. Contrary to the centralized model, D-AFU employs a distributed, scalable, and resilient against failures and system overloads mechanism. Its efficiency is validated using the NS-3 simulator. Three main metrics were used: the data rate allocation, utility per session, and fairness (quantified by the Gini coefficient). D-AFU displays exceptional performance and low latency, particularly vital for real-time applications with high Quality of Service (QoS) requirements.
The dry forest ecosystem is characterized by their rich biodiversity and adaptations to arid cond... more The dry forest ecosystem is characterized by their rich biodiversity and adaptations to arid conditions. This study focused on determining the composition and structure of the vegetation, examining species interactions, and estimating carbon stored in its aboveground biomass (AGB) using an allometric equation proposed for mixed dry forests. We used 10 plots of 10 x 20 m to record data on trees with a diameter at breast height (DBH) ≥ 5 cm. Taxonomic classification was initially obtained using experts and specialized databases. Ecological importance was assessed through the Importance Value Index (IVI), and species association was determined using the Indicator Value Index (IndVal%). We identified 148 individuals of 21 species, 19 genera, and 12 families in four groups with strong associations, with C. Trischistandra standing out for its high IVI. The Kruskal-Wallis test did not show significant differences in carbon stored between plots, and was estimated a storage potential of 70.47 Mg C ha-1. This research highlights the importance of key species in carbon capture, which is crucial for mitigating climate change. Effective management of these species could have a positive impact on the conservation of the dry forest ecosystem and the fight against global warming. This analysis provides a deep understanding of the structure of this ecosystem.
1-In recent years, virtualizing network services and functions has enabled optimizing hardware re... more 1-In recent years, virtualizing network services and functions has enabled optimizing hardware resources on resource-constrained devices, such as CPU, memory, and storage. Traditional virtualization is achieved through virtual machines using a layer known as a hypervisor. While this form of virtualization offers advantages such as scalability and portability, it has disadvantages in terms of performance compared to nonvirtualized deployments. In this context, alternative virtualization technologies (like containers) allow virtualization on the same physical infrastructure, improving overall performance, portability, and service scalability. This paper implements the deployment of network services on the Raspberry Pi development platform, which has limited resources. This is achieved through a multi-container virtualization solution using the Docker Compose tool, based on Docker containerization technology. Finally, a performance analysis of the implemented virtualization solution is conducted in terms of resource utilization by each service. pp. 36-44
This investigation was a case of study in the powder detergent packaging line and aimed to reduce... more This investigation was a case of study in the powder detergent packaging line and aimed to reduce all those wastes that do not add value to the product, increasing the cost of production. Reducing or eliminating waste within the manufacturing industry becomes necessary for sustainable businesses over time and keeps generating development. To achieve it, the Lean Six Sigma DMAIC methodology was implemented in a detergent powder packaging line, to identify the problems that afflicted and made production more expensive. By using quality tools (such as Pareto and Ishikawa diagrams, 5S application, Poka-Yokes, SMED, training personnel, and standardizing processes) it was possible to reduce unproductive times. Energy consumption was reduced by up to 20 %, also efficiency and machine availability increased by 10.98 % and 7.32 %, respectively. The general performance of the line increased by 15.16 %, which translates into significant monthly savings of USD 71 442.05. By applying these improvement techniques, the most significant efficiency was registered in 1 kg packages, going from 47 % to 89 %, approximately. To maintain this productivity and even to perfect it, it is necessary to hire specialized personnel who know the production processes and industrial operations.
The present study aims to know the flow patterns in two nanorefrigerants R600a / CuO and R410A / ... more The present study aims to know the flow patterns in two nanorefrigerants R600a / CuO and R410A / CuO throughout the forced boiling process in horizontal square pipes. Those are obtained using the thermophysical properties of the refrigerants R600a and R410A in state liquid and vapor, as well as the properties of the CuO nanoparticles. The analysis was carried out using two methods: analytical and numerical. The analytical method was established by formulas and correlations through scientific articles and books to find an improvement in the two-phase heat transfer, under the conditions at an inlet temperature of 8 ° C and with a quality range of 0 to 1. This allowed to verify that by adding nanoparticles to the refrigerant, the transition between the flow regimes increases progressively, while the quality of the vapor decreases. For the numerical method, the different transition limits are specified in a simulation process in the Ansys Fluent CFD Software, under established design conditions, which consequently increases the general efficiency of any refrigeration system. 1
Heavy metal contamination of soils and ecosystems is an environmental problem that requires urgen... more Heavy metal contamination of soils and ecosystems is an environmental problem that requires urgent attention due to the ecological problems that it generates. Forest species can be used to mitigate contamination because of their potential to bioaccumulate contaminating metals. The objective of this work was to evaluate the bioaccumulator potential of heavy metals in five forest species that live in mining environments in the Ecuadorian Amazon region. The bioconcentration factor for five forest species, such as: Cedrela odorata, Parkia multijuga, Inga edulis, Cecropia ficifolia and Pourouma cecropiifolia, commonly found in the Ecuadorian Amazon was analysed, based on the relationship between the concentration of the heavy metal in leaves and the soil. Atomic absorption spectrometry was used to analyse heavy metals in leaves and soil samples of each plant specie. The results showed that P. cecropiifolia had the highest bioconcentration factor for lead, C. odorata for cadmium and nickel, and I. edulis had the highest potential for iron and aluminium absorption. No correlation was found between the concentration of each element in the soil and the leaves, which shows that the bioaccumulation capacity of the species studied does not depend on the concentration of the element in the soil. This provides relevant information for the inclusion of these species for phytoremediation purposes.
The purpose of this research was to determine the quality of water for bovine consumption on live... more The purpose of this research was to determine the quality of water for bovine consumption on livestock farms in the El Progreso parish - Galapagos by applying a quality index following the Brown methodology proposed by the National Sanitation Foundation of the United States. Information was collected from the livestock farms through a socio-environmental diagnosis of the area, where five localities were considered: San Joaquín, Las Goteras, Cerro Verde, Puerto Chino and El Progreso from which fifteen livestock farms were selected for the respective sampling of the sources. of water. Therefore, nine parameters were considered for the analysis of the respective water sources: pH, TDS, Fecal Coliforms, electrical conductivity, hardness, nitrites, phosphates, temperature and turbidity. Of the total livestock farms monitored, three of them presented a rating of Good quality in a range of 70 to 90, while the remaining farms recorded values with a Medium classification, which are those that recorded AQI values between 51 to 70 according to the criteria established by the NSF. This research highlights the importance of frequently carrying out analyzes of the water sources from which cattle drink to determine the quality of the resource, and also provide technical advice to ranchers in the area on the management and cleaning of the reservoirs.
With the objective of determining the productive components, chemical characterization, digestibi... more With the objective of determining the productive components, chemical characterization, digestibility and energy contribution of the Brachiaria hybrid vc Mulato I at different ages of cuts in both periods of the year. For which a randomized block design with four repetitions was used. It was sampled in plots of 25 m2, to which a uniformity cut was applied 10 cm from the ground, without irrigation or fertilization. The yield of total dry matter, leaves and stems was determined; the length and width of the leaves; the leaf-stem ratio, chemical composition (CP, NDF, ADF, ADL, CC, Si, P, Ca, ash and OM), energy contributions and digestibility. A double classification analysis of variance was applied to each variable studied and the means were compared according to Duncan. Crude protein decreased with age for both periods, showing significant differences between all ages. The best values were shown at 30 days of cutt (9.47 and 10.40 % in the rainy and dry periods respectively), the fiber increased with age with its best values at 75 days with (71.39 and 70.11 % in the rainy periods and little rain), aspects that conditioned the quality with a decrease in digestibility and energy intake. The yield of the plant was affected by the periods of the year, being higher in the rainy period. It is concluded that the increase in regrowth age directly influences the depression of nutritional quality and yield in both periods of the year.
Precision agriculture optimizes crop management by providing accurate data on soil chemical prope... more Precision agriculture optimizes crop management by providing accurate data on soil chemical properties, thereby improving agricultural productivity and sustainability. This study aims to develop models to estimate soil chemical properties, such as pH, electrical conductivity (EC), and organic matter (OM), by analyzing drone-captured RGB images. The methodology included photogrammetric flights with a DJI Phantom 4 Pro drone equipped with a 20 Mpx camera and simultaneous sampling, laboratory analysis and on-site measurements, with Royal Eijkelkamp EC meter set voor grond multiparameter sensors and pH meter set for soil and water. The aerial images were processed with the PIX4Dmapper software, to generate the orthophoto and spectral bands. With the resulting orthophoto of 1.6 cm/pixel, eight spectral indices were calculated, using the spatial analysis tools of ArcGIS software. The in situ results showed an average pH value of 5.83, indicating a slightly acidic soil, and an EC of 1.09 dS/m, suggesting a soil with a low concentration of dissolved salts. Laboratory analyses showed a medium-high content of OM, with an average of 5.19 %. A strong correlation was found between OM and pH_index with coefficients of determination R2=0.55, while moderate correlations were also observed between pH with pH_index and EC with sal_index6 with coefficients of determination R2=-0.39 and R2=0.42 respectively. The aforementioned results allowed the generation of two models for the estimation of these variables from RGB images.
Aircraft operators often modify aircraft configurations, install new equipment, and alter airfram... more Aircraft operators often modify aircraft configurations, install new equipment, and alter airframes to accommodate this equipment, leading to operations in flight envelopes different from original design profile. These modifications necessitate airframe structural assessments, which typically require comprehensive aircraft design data, often unavailable to operators. This study aims to develop and validate a practical method for finite element analysis (FEA) of aircraft structures in the absence of this detailed design data. Focusing on a case study involving structural analysis of an aircraft wing, this study presents assumptions and idealizations used to develop 2.5D finite element (FE) model of the wing. Fidelity of this model is established by comparing FE analysis results with experimental data. Key validation metrics include reaction forces, load distribution at wing-fuselage attachments, and deformation at reference points on the wing under design load. Comparison between FE analysis and experimental results is carried out to substantiates accuracy of these geometric simplifications and idealizations of load-carrying behaviour of structural members. Therefore, practicality of these idealizations in absence of design data is demonstrated. This study offers a novel approach for structural assessments of aircraft without relying on proprietary design data. The validated method enhances capability of aircraft operators to perform effective structural analyses, thereby extending service life of aircraft with continued airworthiness.
Artificial neural networks (ANNs) have become indispensable tools for solving classification task... more Artificial neural networks (ANNs) have become indispensable tools for solving classification tasks across various domains. This systematic literature review explores the landscape of ANN utilization in classification, addressing three key research questions: the types of architectures employed, their accuracy, and the data utilized. The review encompasses 30 studies published between 2019 and 2024, revealing Convolutional Neural Networks (CNNs) as the predominant architecture in image-related tasks, followed by Multilayer Perceptron (MLP) architectures for general classification tasks. Feed Forward Neural Networks (FFNN) exhibited the highest average accuracy with a 97.12%, with specific studies achieving exceptional results across diverse classification tasks. Moreover, the review identifies digitized images as a commonly utilized data source, reflecting the broad applicability of ANNs in tasks such as medical diagnosis and remote sensing. The findings underscore the importance of machine learning approaches, highlight the robustness of ANNs in achieving high accuracy, and suggest avenues for future research to enhance interpretability, efficiency, and generalization capabilities, as well as address challenges related to data quality.
The Intensity-Duration-Frequency (IDF) curves are a way to visualize and represent extreme hydrom... more The Intensity-Duration-Frequency (IDF) curves are a way to visualize and represent extreme hydrometeorological rainfall events. In this article, an analysis of convective rainfall events recorded at the La Piedra Meteorological Station, Villa Clara, Cuba, was conducted. To develop IDF curves, the 2006-2019 time series was analyzed. A partial duration series was generated, including intervals from 20 minutes to 4320 minutes, subjected to an outlier detection process. The series was divided into two categories: one for durations ≤ 720 minutes and another for durations > 720 minutes. The resulting series underwent nonparametric tests to assess their independence, randomness, homogeneity, and seasonality. Subsequently, they were fitted to the Generalized Pareto probability distribution and to a parametric equation of the Montana model, and then the curves were plotted for return periods of 10, 50 and 100. The Montana model led to obtaining correlation coefficients greater than 0.90 compared to the other methods used, significantly improving the quality of the fit in both categories. This research provides information to understand and plan the management of intense climatic phenomena and adequate risk management in an area where such studies are lacking, facilitating access to crucial data essential in the design and execution of hydraulic engineering projects in the region.
Manufacturing companies face demand fluctuations and must deliver the required quantity of parts ... more Manufacturing companies face demand fluctuations and must deliver the required quantity of parts to their customers within the required time; however, companies face different challenges in fulfilling them. One is technological advances, which make it impossible for them to compete with other countries, such as China, due to financial issues. Therefore, manufacturing companies use continuous improvement methodologies to achieve better performance in their processes. Six Sigma and Lean Manufacturing are some of the best-known approaches. This article briefly presents the application of a lean sigma approach oriented to solving problems. This research proposes a methodology based on Lean Sigma that contrasts what different authors currently do: continuous improvement projects that take up to 12 months to produce results and do not solve a problem. This implementation is conducted in a process that manufactures metal parts and fails to deliver them on time to its customers. Using tools such as the Single Minute Exchange of Die (SMED) in a production line, on-time deliveries were increased from 89 % to 96 %; at the same time, the model change times were reduced by approximately 60 %, which is required for the implementation of this methodology for only four weeks, unlike the traditional six-sigma approach that can take up to 12 months to improve the process.1
The research addresses the study of heat exchange between heavy crude oil and the environment dur... more The research addresses the study of heat exchange between heavy crude oil and the environment during surface pumping, specifically of a crude oil with an API gravity of 17.5, under the particular atmospheric conditions of Eastern Ecuador. The main objective of the study is to evaluate the temperature loss in a 50-meter segment of SCH-80 pipe, with a diameter of 4 inches, used for the transportation of heavy crude. This aims to understand how heavy crude loses temperature and to determine the convective coefficient, knowing that the heat loss from the fluid to the environment occurs mainly by convection. This is to determine what the temperature losses will be in longer pipe sections. For this purpose, a methodology using computational fluid dynamics (CFD) simulation was employed, a key tool for predicting the thermal behavior of crude in interaction with the environment. It was determined that the convective coefficient is 52 W/m2.K, and there is a temperature loss of 3.2 K in the 50-meter section. With this data, future research could evaluate potential heating technologies that facilitate the transport of heavy crude oil. This approach would allow for exploring innovative solutions to improve efficiency and effectiveness in managing heavy crude, facing one of the main challenges in its transport: managing its high viscosity.
Environmental pollution from transportation has been a fundamental challenge for humanity through... more Environmental pollution from transportation has been a fundamental challenge for humanity throughout history, with conventional fuels contributing significantly to environmental degradation. This project seeks to suppress pollution and reduce noise generated by motorcycle taxis, whether for personal and/or private use. The main objective of the research work was to implement an electrolyzer in the combustion system of a motorcycle taxi to suppress environmental pollution and reduce noise. Methods included vehicle preparation, electrolyzer installation, battery adjustment, hydrogen generation, emissions measurement, safety, and data collection. As a result, the electrolyzer was implemented in the single-cylinder motorcycle taxi; The noise limit allowed at work in Peru is 85 dB, which is equivalent to 100 % noise at most; When using gasoline, a value of 76.4 dB was obtained, equivalent to 89.88 % noise, and when using hydrogen, a value of 71.7 dB was obtained, equivalent to 84.35 % noise, therefore, the total noise reduction was 4.70 dB (5.53 %) than established. The discussion highlighted that hydrogen is a clean fuel, with zero emissions and only emitting water vapor instead of polluting gases [5]. The conclusion highlights the critical importance of the research, supported by the total reduction of 5.53 % of noise with this new technology and in turn external sources support that using hydrogen produced a smoother and quieter combustion; Regarding the useful life of the engine, due to the cleaner and more efficient combustion, the accumulation of waste was reduced, which benefits reducing the wear of internal components and the need for costly maintenance.
There is evidence of the high use of the neonicotinoid insecticide thiamethoxam, in tropical crop... more There is evidence of the high use of the neonicotinoid insecticide thiamethoxam, in tropical crops, for its effectiveness in the control of soil and plant pests. The objective of this study was to know the residuality and concentration of thiamethoxam in the papaya agroecosystem, in the main papaya fruit producing zone in the central area of the Gulf of Mexico. It was carried out during a papaya growing cycle with watermelon rotation; the taking of samples was according to the technique established by the NOM-AA-103-1988 for leaves and for fruit the NMX-FF-041-1996 by the method of quartering in papaya and watermelon, the samples were analyzed with a HPLC-UV, the data obtained were statistically analyzed by parametric and non-parametric Kruskal-Wallis tests. The presence of thiamethoxam was found in papaya and watermelon cultivation plants, the concentrations in papaya leaves reported a maximum value of 0.29 mg/kg, while for the leaves of the watermelon rotation fruit it was 0.15 mg/kg. In papaya fruit, thiamethoxam concentrations are within a range of 0.24 to 0.32 mg/kg. The concentrations and residuality of thiamethoxam mainly exceed the maximum tolerance and residuality limits of the EFSA and FAO. 1
Passive Optical Networks (PONs) are essential in optical communications to meet the increasing de... more Passive Optical Networks (PONs) are essential in optical communications to meet the increasing demand for network capacity and connected users, ensuring reliable and adaptable connections for data transmissions. These networks also simplify infrastructures and efficiently utilize energy by eliminating the need for active devices. In this context, Ultra-Dense Wavelength Division Multiplexing (UDWDM) is one of the most prominent solutions for data transmission. This technology uses the narrow separation between channels from 25GHz and even as small as 6.25GHz to increase the transmission capacity. This document analyzes the performance of UDWDM considering the transmission of three simultaneous channels in a PON network for which three different scenarios have been considered for the analysis with the following parameters: i) transmission speed from 10 Gbps to 17 Gbps, ii) the distance from 10 km to 20 km and iii) the separation between channels of 15GHz, 20GHz, and 25GHz. The performance metrics for the analyzed scenario are the bit error rate and the eye diagram. To ensure the reception of the transmitted channel, an analysis of raised cosine and Gauss filters is also discussed. Including these filters allows for verifying whether their use enhances the performance of the channels compared to transmission without a filter. This is crucial for understanding how filters can optimize the quality and reliability of data transmission in a PON, which is of great importance in environments where high efficiency and connection quality are required.
In this paper, an assessment of the state of coastal territories of Ecuador monitoring issue is c... more In this paper, an assessment of the state of coastal territories of Ecuador monitoring issue is conducted. The use of an autonomous robotic aerial platform is proposed as a technical solution to enhance the efficiency of remote surveillance missions performed by national security services along coastline. Considering the UAV nonlinear flight dynamics, as well as the missing information of the environment, is designed a UAV hierarchical control structure composed of an adaptive PID based MPC control strategy. The implementation of an adaptive PID based MPC controller leads to significantly improve the UAV optimal trajectory tracking task, as well as satisfy properties such as adaptiveness, self-learning, and capability of handling uncertainties caused by the unpredictable behavior of sea currents and wind loads retaining robust performance features. In this work, the investigation of external disturbances on UAV stabilization and positioning accuracy considers swirling wind flows and short-term wind gusts. These correspond to deterministic and random processes, are mathematically represented as trigonometric functions with random amplitudes determined by the gust coefficients and the wind loading periods of the pulses. The established range is given by a set of several observations of wind loads in the coastal territories of Ecuador. The analyzed data is collected from the database of national meteorological stations. Finally, the simulation process of the perturbed controlled motion of the UAV along a segmented linear trajectory, as well as the data analysis and graphics are carried out in the MATLAB environment.
Within the context of agricultural ecosystems, understanding the nutritional physiology of insect... more Within the context of agricultural ecosystems, understanding the nutritional physiology of insects and their host plant preferences is essential for optimizing pest management strategies and improving crop production. In this study, we conducted an in-depth examination of the nutritional physiology of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in the context of different host plants, specifically wheat varieties, in comparison to maize. Our investigation focused on key parameters, including the Relative Consumption Rate (RCR), Relative Growth Rate (RGR), and Efficiency of Conversion of Ingested food (ECI) of S. frugiperda fed on different wheat varieties including: Dilkash-20, Fakhar-E-Bhakkar-17, Subhani-21, Faisalabad-08, and Akbar-19 in comparison to maize (NK-6654). The results revealed that S. frugiperda displayed a significantly (P < 0.05) higher RCR (8.08 g/g/day), RGR (1.50 g/g/day), and ECI (25.1 %) when feeding on maize, followed by Fakhar-E-Bhakkar-17 (RCR =7.00 g/g/day, RGR =1.24 g/g/day and ECI =21.4 %) and Akbar-19 (RCR = 6.06 g/g/day, RGR = 1.04 g/g/day and ECI =19.7 %) wheat varieties after 1 week of feeding. The lowest values of all these nutritional parameters were recorded on the Dilkash-20 variety (RCR = 2.98 g/g/day, RGR = 0.38 g/g/day, and ECI = 7.94 %). These findings offer valuable insights into the nutritional interactions between S. frugiperda and the host plants, shedding light on potential implications for pest management strategies and crop patterns.
The Internet of Things (IoT) has the potential to revolutionize healthcare by enabling remote pat... more The Internet of Things (IoT) has the potential to revolutionize healthcare by enabling remote patient monitoring, personalized care and disease prevention. In Ecuador, research on IoT in the healthcare field is rapidly expanding. However, there’s a need for a clearer understanding of the current state of this research. This study examines the contributions of Ecuadorian authors in this field through their publications in two globally impactful bibliographic databases. The methodology employed is a systematic review using the PRISMA statement, resulting in a final stage comprising 23 articles. These publications encompass system proposals, prototypes, and reviews with applications in areas such as epidemiology, cardiology and nursing. The recurrent mention of patient information privacy is a challenge in implementing IoT-based healthcare systems. The conclusions emphasize that future work perspectives should address the challenges identified, considering the growing trend of publications from Ecuadorian authors.
This paper introduces the Distributed Utility Function Algorithm (D-AFU) as a notable progression... more This paper introduces the Distributed Utility Function Algorithm (D-AFU) as a notable progression in managing and optimizing network traffic within distributed settings. Based on the utility function principle, D-AFU dynamically adjusts data rate in response to ever-changing network demands, with optimal performance and a higher user experience. Contrary to the centralized model, D-AFU employs a distributed, scalable, and resilient against failures and system overloads mechanism. Its efficiency is validated using the NS-3 simulator. Three main metrics were used: the data rate allocation, utility per session, and fairness (quantified by the Gini coefficient). D-AFU displays exceptional performance and low latency, particularly vital for real-time applications with high Quality of Service (QoS) requirements.
The dry forest ecosystem is characterized by their rich biodiversity and adaptations to arid cond... more The dry forest ecosystem is characterized by their rich biodiversity and adaptations to arid conditions. This study focused on determining the composition and structure of the vegetation, examining species interactions, and estimating carbon stored in its aboveground biomass (AGB) using an allometric equation proposed for mixed dry forests. We used 10 plots of 10 x 20 m to record data on trees with a diameter at breast height (DBH) ≥ 5 cm. Taxonomic classification was initially obtained using experts and specialized databases. Ecological importance was assessed through the Importance Value Index (IVI), and species association was determined using the Indicator Value Index (IndVal%). We identified 148 individuals of 21 species, 19 genera, and 12 families in four groups with strong associations, with C. Trischistandra standing out for its high IVI. The Kruskal-Wallis test did not show significant differences in carbon stored between plots, and was estimated a storage potential of 70.47 Mg C ha-1. This research highlights the importance of key species in carbon capture, which is crucial for mitigating climate change. Effective management of these species could have a positive impact on the conservation of the dry forest ecosystem and the fight against global warming. This analysis provides a deep understanding of the structure of this ecosystem.
1-In recent years, virtualizing network services and functions has enabled optimizing hardware re... more 1-In recent years, virtualizing network services and functions has enabled optimizing hardware resources on resource-constrained devices, such as CPU, memory, and storage. Traditional virtualization is achieved through virtual machines using a layer known as a hypervisor. While this form of virtualization offers advantages such as scalability and portability, it has disadvantages in terms of performance compared to nonvirtualized deployments. In this context, alternative virtualization technologies (like containers) allow virtualization on the same physical infrastructure, improving overall performance, portability, and service scalability. This paper implements the deployment of network services on the Raspberry Pi development platform, which has limited resources. This is achieved through a multi-container virtualization solution using the Docker Compose tool, based on Docker containerization technology. Finally, a performance analysis of the implemented virtualization solution is conducted in terms of resource utilization by each service. pp. 36-44
This investigation was a case of study in the powder detergent packaging line and aimed to reduce... more This investigation was a case of study in the powder detergent packaging line and aimed to reduce all those wastes that do not add value to the product, increasing the cost of production. Reducing or eliminating waste within the manufacturing industry becomes necessary for sustainable businesses over time and keeps generating development. To achieve it, the Lean Six Sigma DMAIC methodology was implemented in a detergent powder packaging line, to identify the problems that afflicted and made production more expensive. By using quality tools (such as Pareto and Ishikawa diagrams, 5S application, Poka-Yokes, SMED, training personnel, and standardizing processes) it was possible to reduce unproductive times. Energy consumption was reduced by up to 20 %, also efficiency and machine availability increased by 10.98 % and 7.32 %, respectively. The general performance of the line increased by 15.16 %, which translates into significant monthly savings of USD 71 442.05. By applying these improvement techniques, the most significant efficiency was registered in 1 kg packages, going from 47 % to 89 %, approximately. To maintain this productivity and even to perfect it, it is necessary to hire specialized personnel who know the production processes and industrial operations.
The present study aims to know the flow patterns in two nanorefrigerants R600a / CuO and R410A / ... more The present study aims to know the flow patterns in two nanorefrigerants R600a / CuO and R410A / CuO throughout the forced boiling process in horizontal square pipes. Those are obtained using the thermophysical properties of the refrigerants R600a and R410A in state liquid and vapor, as well as the properties of the CuO nanoparticles. The analysis was carried out using two methods: analytical and numerical. The analytical method was established by formulas and correlations through scientific articles and books to find an improvement in the two-phase heat transfer, under the conditions at an inlet temperature of 8 ° C and with a quality range of 0 to 1. This allowed to verify that by adding nanoparticles to the refrigerant, the transition between the flow regimes increases progressively, while the quality of the vapor decreases. For the numerical method, the different transition limits are specified in a simulation process in the Ansys Fluent CFD Software, under established design conditions, which consequently increases the general efficiency of any refrigeration system. 1
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