Heart failure (HF) is one of the leading causes of hospitalization in older adults, generating high burden on healthcare systems and negative impact in quality of life. Telemonitoring is a method that has shown effectiveness in reducing hospital readmissions and manage HF. Current systems face challenges related to usability, unfriendly interfaces, and unreliable data. To address these issues, Fundaci & oacute;n Cardiovascular de Colombia developed TELSY based in design thinking methodology, a user-centered telemonitoring system. The aim of this article is to describe the technological development of the TELSY program, from its creation to its validation in laboratory environments. TELSY integrates three subsystems: TELSY Home, vital signs monitor that records biometric and self-reported data; TELSY Web, a platform for monitoring and clinical follow-up; and TELSY App, a mobile application that enables interaction between patients and healthcare professionals. Usability evaluations were conducted combining patient testing, healthcare professional assessments, and expert heuristic reviews. Results showed that while some tasks presented higher error incidence, overall satisfaction was high. TELSY App achieved strong acceptance and highly useful by participants. TELSY demonstrates potential as a scalable and sustainable solution to improve remote care and reduce hospitalizations in HF.
Helicoidal heat exchangers are used in all kinds of industries, domestic refrigeration is one of them, due to their geometrical characteristics which improve the heat transfer of fluids. Refrigerant R600a is one of the most studied fluids in the condensation process due to its extensive use throughout the years. Nanoparticles can enhance the heat transfer and phase change of the refrigerants in the condensation process. Therefore, Ansys Fluent is employed to carry out a numerical analysis of the nano refrigerant CuO-R600a, the models used in the simulation were made with the multiphase Euler model and condensation under the Lee approach, the simulations were with nanoparticle concentration varies from 0.1 to 3 %. Considering 39.37 degrees C as the saturation temperature of the refrigerant R600a at a pressure of 1 MPa, and 300 kg/m2s as the mass flux. In the simulations six different condensers are tested, but the condenser with 120 mm in coil diameter and 30 mm in pitch shows better condensation of the refrigerant R600a. Nevertheless, by adding nanoparticles the condensation process presents negative results, and as the nanoparticle concentration increases the condensation percentage plummets. Thereby, the nano refrigerant does not show better heat transfer nor phase change as the base refrigerant R600a.
The primary goal of any industry is to sustain and grow over time and achieve success in all dimensions. Industries currently aim to enhance quality at every stage of their processes, which fosters competitiveness and productivity, particularly in areas with defects and deficiencies. This is evident in the implementation of Lean and Six Sigma methodologies. This study explores the relationship between process improvement and different industrial sectors. To achieve this, a systematic literature review was conducted using various reputable sources between 2018 and 2024. The Scopus database served as the primary resource, from which content was synthesized and extracted from 51 articles selected according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The review findings indicate significant concerns regarding low productivity, production defects and insufficient process standardization. These issues stem largely from inadequate staff training, persistent process defects, improper equipment use, and delays in the processes. Additionally, effectively utilizing metrics to gauge production and product quality can reduce defects and enhance process indicators and operational efficiency. In conclusion, cost reduction and heightened efficiency can optimize resource utilization and improve customer satisfaction.
In Ecuador, extensive coconut (Cocos nucifera) harvesting generates large quantities of waste, including husks, shells, and fibers, posing environmental and economic challenges. This study explores the densification of coconut waste (CW) into pellets and briquettes to address these issues. The process involved raw material collection, pretreatment, drying, grinding, sieving, mixing, pelletizing, and briquetting, using cassava starch (CS) as a binder. Two CW-to-CS compositions were tested for each type of fuel. Key physical and combustion properties, such as higher heating value, moisture, volatile matter, fixed carbon, ash content, bulk density, and friability, were analyzed. Results showed that the PCA91 pellet sample (90% CW, 10% CS) achieved the best performance with a higher heating value of 15,350 J/g and 11.54% moisture content. Similarly, the BCA91 briquette sample (90% CW, 10% CS) demonstrated better performance with a heating value of 14,950 J/g and 13.75% moisture content. Most samples met the heating value and bulk density requirements of the Swedish SS187120 and Colombian NTC 2060 standards, although some fell short on ash, volatile matter, and fixed carbon content. Adjusting the CW-to-CS ratio could optimize biofuel properties, balancing energy output and stability, highlighting coconut waste's potential as a sustainable biofuel.
This study analyzes the land-use transitions driven by urbanization in Colombia's 32 departmental capitals between 1992 and 2019. Using annual land cover maps with a spatial resolution of 300 meters from the Climate Change Initiative of the European Space Agency (CCI-ESA), we assess how urban expansion has altered landscapes, with a focus on grasslands, croplands, and forests. We identify the dominant land-use transitions in each city and explore the potential conflicts between urban development and the preservation of ecosystem services. Our results show that grasslands were the most affected by urbanization, followed by croplands and forests. The impact of urbanization has intensified since 2000, especially following the implementation of territorial planning regulations under Law 388 of 1997. Cities like Bogot & aacute;, Medell & iacute;n, and Cali predominantly expanded into grasslands, while others such as Bucaramanga, Pereira, and Ibagu & eacute; experienced significant conversions of agricultural lands. In cities like Mocoa, Leticia, and In & iacute;rida, urbanization encroached on forested areas. The potential land-use conflicts (LUCs) identified in this study highlight the threat to food security, biodiversity, and water regulation, particularly in cities where agricultural and forested lands are being urbanized. The findings underscore the need for a more integrative approach to land management that balances urban growth with the preservation of ecosystems. Nature-based solutions and collaborative decision-making are crucial for mitigating the negative impacts of urbanization while fostering sustainable and inclusive urban development.
The Department of Antioquia, Colombia, produces 47% of the mining tailings linked to national gold extraction. These residues, stored in dam-like deposits, contain toxic substances such as heavy metals, posing serious risks to the environment and public health. Due to their high silica and alumina content, these tailings could be repurposed as alternative cementitious materials. Hybrid cements, formed by combining Portland cement with alkaline-activated materials, offer a lower environmental impact and support circular economy practices. In this study, the potential use of Antioquia's mining tailings as precursors for hybrid cement production was evaluated. Sodium carbonate and sodium silicate were used as alkaline activators, and curing was performed at room temperature. The tailings'chemical composition showed suitable levels of silica and alumina for geopolymer synthesis. Concrete specimens were prepared using hybrid cement and three types of aggregates: sand, coarse tailings, and recycled polymer. After 28 days of curing, the highest compressive strength was 568.6 kN +/- 6.1 with coarse tailings, followed by 550.3 kN +/- 7.9 with sand, and 325.3kN +/- 7.5 with recycled polymer. These results demonstrate the feasibility of using mining residues in sustainable construction applications.
Musculoskeletal injuries are a leading cause of disability worldwide. Orthopedic surgery commonly employs osteosynthetic devices, such as compression plates, which require proper osseointegration for successful outcomes. Although titanium and its alloys are widely used for their mechanical strength and biocompatibility, limited osseointegration can result in clinical complications and require surgical reintervention. In this study, an integrated computational model combining finite element analysis in COMSOL with a biological module in MATLAB was developed to simulate the osseointegration process in titanium compression plates. The model enabled the assessment of how plate geometry and mechanical stress distribution directly influence cellular responses at the fracture site. Results revealed localized compressive stresses along the fracture line, with a maximum value of 140 MPa. This stress promoted bone formation by day 40, with complete consolidation occurring around day 100. These findings suggest that the proposed model can serve as a predictive tool for optimizing osteosynthesis material design and improving clinical outcomes, with applications in the development of next-generation implants.
This study investigates mobility patterns within the University of Cuenca community, focusing on transport mode preferences and the potential for modal shifts toward sustainable transport. Unlike previous studies that primarily examine urban transport in general contexts, this research uniquely explores a university setting in a mid-sized city in a developing country, providing insights into transport choices' demographic and behavioral determinants. An online survey with 1,253 university members reveals distinct differences between students and employees: Students predominantly use active transport modes, while employees rely on private vehicles. Logistic regression analysis highlights key factors influencing mobility preferences, such as age, gender, and income. Notably, the female students tend to prefer private vehicle use, while younger and lower-income students prefer sustainable transport options. The study also examines the willingness to adopt public and active transport modes, identifying targeted interventions, such as improving public transit safety and infrastructure. These findings contribute to understanding sustainable mobility in university communities and provide actionable insights for urban planning and policy development in comparable settings. This research establishes a pre-pandemic baseline for evaluating post-pandemic shifts in commuting behaviors. It offers a framework for advancing sustainable transport strategies in mid-sized cities of developing nations.
This study focuses on the numerical analysis of the interaction between the exit flows of two supersonic nozzles, using the distance between their longitudinal axes as a parameter. The analysis is conducted in OpenFOAM, assuming two-dimensional, inviscid flow. The methodology employed to simulate flow in a nozzle is validated against experimental data and is subsequently used to investigate the interaction with a second nozzle. The numerical results indicate that discharge flows interfere, even from distant nozzles.
Antimicrobial resistance in Streptococcus pneumoniae poses a growing challenge to global public health. Although this bacterium has been widely studied, the enzyme thiamine phosphate synthase, essential for its metabolism, lacks an experimentally resolved three-dimensional structure. This study aimed to identify compounds with inhibitory potential against ThiL using structure prediction and molecular docking tools. The 3D structure was modeled using AlphaFold2 and its active site was adjusted based on homologous templates. Bioactive compounds from the Zinc20 and PubChem databases were virtually screened and their binding affinities were evaluated using AutoDock Vina. The results highlighted Bindarit as a potential inhibitor, exhibiting higher binding affinity (-9.78 kcal/mol) than the natural ligands. These findings suggest its potential as a targeted antimicrobial therapy. Further validation through in vitro and in vivo experiments is recommended.
This study reports a structural equation model (SEM) in which Lean Manufacturing tools associated with quality control are related to the benefits obtained in the Maquiladora industry of Ciudad Juarez (Mexico). A questionnaire was designed and applied to the regional industry to obtain information about the implementation levels of the Plan-Do-Check-Act (PDCA), Total Quality Management (TQM), and Poka-Yoke (PYK) tools and their relationship with economic sustainability (ECS). The variables were related through six hypotheses that were validated using information from 411 responses to a questionnaire. The objective of this research was to empirically and statistically measure the relationships of PDCA, PYK, and TQM with ECS to allow managers and decision-makers to better optimize the resources available to their companies. The findings indicate that the relationship between PDCA and PYK is the strongest of the models, and it is concluded that there is enough statistical evidence to state that PDCA, TQM, and PYK influence the ECS in Mexican maquiladora industries. Therefore, Top Management should focus their efforts on quality control in the use of a complete plan for the implementation of these tools to support decisions in the productive area and improve financial income.
Blockchain technology is attracting growing attention across various sectors, including public administration, due to attributes such as decentralization, reliability, predictability, network distribution, profiling, and security. In the public sector, blockchain can enhance transparency, reduce bureaucratic inefficiencies, and build trust in governmental processes. However, barriers such as adoption challenges, interoperability issues, and lack of standardization hinder widespread implementation. Developing tailored models is necessary for integrating blockchain into public administration to overcome these obstacles. This study proposes a novel model to assess blockchain adoption in this domain, focusing on key facilitating factors. The research employs the Technology–Organization–Environment (TOE) framework, which considers factors influencing the intention to adopt and use technology within organizations. The framework was applied to public organizations through a study involving 50 public officials from eight municipal mayor’s offices in Colombia. The resulting model identifies seven TOE-related factors associated with blockchain adoption, validated via Partial Least Squares Structural Equation Modeling (PLS-SEM). Of these, five factors emerged as most relevant. Notably, Perceived Network Enhancement (PNE) and Perceived Interoperability (PI) showed stronger correlations with Perceived Lack of Technological Knowledge (PLTK) than did Perceived Technological Volatility (PTV) and Perceived Standardization Uncertainty (PSU). Research findings show the relationship between technological capabilities, institutional preparedness, and the knowledge required for implementing blockchain adoption in public administration, offering crucial information for policymakers and practitioners aiming to incorporate blockchain into government systems effectively.
This paper proposes an immune fuzzy sliding mode kinematic controller integrated with a proportional derivative dynamic controller for trajectory tracking by a nonholonomic differential-drive wheeled mobile robot subject to uncertainties and disturbances as well as its extension to the leader-follower formation control by multiple robots using the separation-bearing strategy. To deal with the drawbacks of a traditional first-order sliding mode control, such as the chattering phenomenon and the requirement of a priori knowledge of the bounds of uncertainties and disturbances, inspired by a regulation mechanism of the humoral immune response, it is derived a fuzzy system to establish the control reaction effect for an artificial immune system design to adjust online the gains of the control robustness portion adaptively. Furthermore, this paper proposes an obstacle avoidance strategy based on a reactive approach, being a variable avoidance radius also considered, to navigate in execution time the leader robot around static obstacles during the trajectory tracking. Simulation and experimental results demonstrate the effectiveness of the proposed controller with obstacle avoidance, and the Lyapunov theory proves the stability of the closed-loop control system.
In this study, a failure analysis was conducted on two CuZn40Pb2 valves for CO2 gas storage cylinders. The valves failed during maintenance and refilling operations performed by the operator. The investigation involved visual inspection, fractographic analysis, chemical composition determination, microstructure examination, and calculations of principal stresses and safety factors for the failed valves. The results indicated two significant issues: dezincification and stress corrosion cracking (SCC). Zinc levels near the fracture surface were found to be ten times lower than the standard value of the CuZn40Pb2 alloy, and the phenomenon was observed in both the valves and the cylinder probes. Additionally, tortuous cracks, typical of SCC, were observed near the inner threads of the valves and close to the fractured surface. These phenomena were caused by the convergence of several critical factors: moisture and/or an ion-rich environment in the system, and possible overloads due to excessive force applications. Stress calculations in two critical operational scenarios showed that tightening/loosening forces near 30 kg applied to a flowmeter could induce overload failures in the valve.
The study addresses the need to structure technological routes in the province of Pastaza, where the lack of planning has limited agro-industrial development. Through a technical and objective prioritization, agricultural, livestock, and forestry resources with the highest transformation potential were selected, ensuring their valorization within efficient and sustainable production systems. The methodology was based on the grouping of technologies by sector, establishing selection criteria grounded in production volume, economic value, transformation potential, and environmental sustainability. Applicable technologies were identified for sugarcane, milk, and pigüe, considering biorefinery processes, waste utilization, and the optimization of production routes through P-Graph. The results indicate that the province produces 10,201 tons of sugarcane annually, 8,471 liters of milk daily, and has a forest cover of 749,633 hectares, demonstrating the potential of these resources for bioethanol production, biofuels, dairy derivatives, and kraft pulp. It is concluded that the integration of these technological routes contributes to productive diversification, the strengthening of the local bioeconomy, and agro-industrial sustainability. However, the adoption of these technologies faces challenges related to investment, infrastructure, and market acceptance. It is advisable to conduct experimental validation of the processes and to develop strategies that promote their implementation, ensuring a positive impact on the competitiveness of the agro-industrial sector and the efficient management of resources in Pastaza.
The use of recycled-concrete-aggregate (RCA) in asphalt mixtures is considered a viable technique from a technical standpoint to provide a solution to the environmental problem of final waste disposal. Likewise, the use of crumb-rubber-modified asphalts (CRMA) could contribute to this end. This article evaluated the physical-mechanical behaviour of a hot-mix asphalt (HMA) manufactured with CRMA and partially replacing the coarse fraction of the coarse aggregate of natural (NA) with RCA. For this purpose, four HMA mix designs were conducted by Marshall test, considering NA and RCA, and using as binders an asphalt cement AC 60-70 and CRMA. The mechanical performance was measured by performing Marshall, Indirect-Tensile-Strength (ITS), resilient modulus (RM), and permanent deformation. Resistance to moisture damage was also measured by calculating the Tensile Strength Ratio (TSR). The results show that mixtures with RCA require higher asphalt content. When replacing NA with RCA, HMA decreases its mechanical strength under monotonic and cyclic loading. Likewise, its resistance to moisture damage decreases. Contrary to the above, CRMA tends to increase the mechanical performance of the mixtures. However, the CRMA content used in this study was insufficient to adequately cover and adhere to the RCA, generating a mix that undergo the worst performance.
In the present study were evaluated a biological treatment and several Advanced Oxidation Technologies (AOTs), including TiO₂/UV-VIS, H₂O₂-UV-VIS and TiO₂/H₂O₂/UV-VIS for industrial wastewater treatment. The experiments were carried out both in a laboratory reactor and in a 120 L/s pilot plant with autonomous operation under solar energy. The individual application of the biological treatment using a commercial bacteria strain led to a significant decrease in total hydrocarbons, sulfates, total organic carbon (TOC), hardness, alkalinity, biochemical oxygen demand (BOD5), and chemical oxygen demand (COD), in the starting industrial wastewater sample. It was also observed that the application of UV-VIS/H₂O₂/TiO₂ as combined treatments, is more effective than biological treatment and individual AOTs reducing certain quality parameters, such as conductivity, chlorides, nitrates, turbidity, fats and oils, total suspended solids, settleable solids, acidity, TOC, total coliform bacteria and in the removal of heavy metals (Zn, Cu, Cr, Ni, Fe, Pb). In addition, the use of a sequential treatment, initially applying a AOTs and subsequently a biological treatment, resulted in an improvement in the removal of contaminants such as chlorides, heavy metals (Fe, Pb), nitrates and hardness. Thus, the results suggest that the sequential combination of AOTs and biological treatment is an effective strategy for the recovery of industrial wastewater, achieving a greater reduction of contaminants compared to the application of each treatment separately, thus improving the final quality of the treated water.
The construction of roads often involves cuts and embankments, requiring the use of earth retaining walls. This study estimates a resilience index for these systems based on four fundamental criteria: robustness, redundancy, resourcefulness, and recovery. To achieve this, quantitative weightings based on a multicriteria analysis were applied to the service life of both a rigid and a flexible retaining wall systems near the city of Bogotá, Colombia, considering maximum surface acceleration and groundwater level variations. The results indicate a resilience index of 0.78 for the rigid system and 0.82 for the flexible system, indicating that the flexible system exhibits a higher resilience capacity. These findings can inform risk management policies and resource optimization strategies, ultimately reducing entropy during the design, construction, and operation phases of road projects.
Nowadays the world’s energy transition is transforming the paradigm of how power systems are being developed. This is causing new alternative systems to be included into these power grids. One of these alternatives is the DC microgrids that, due to their reliability, operability, and control characteristics, are currently considered sustainable solutions within this energy transition. This paper outlines the inclusion of DC microgrids as a technological solution to the problem of Non-Interconnected Zones (NIZ) in Colombia. Specifically, this study presents a detailed comparison of a DC microgrid with respect to an AC microgrid, discusses regulatory issues for the inclusion of these elements in the National Interconnected System (NIS), and evaluates a case study in a NIZ of Colombia such as Vigía del Fuerte in Antioquia. Based on the results, it is clearly deduced that DC microgrids are a feasible and profitable solution in NIZ in Colombia and these DC small-scale grids may decrease the total Net Present Cost (NPC) and the Levelized Cost of Energy (LCOE) by 10% for both, compared to AC microgrids for different microgrid configurations. Additionally, regarding these sustainable initiatives, it is essential to standardize the procedures associated with the commissioning of the microgrids, especially with the aspects of connection, protections, and operational adjustments if required by the regional utility company.
The valorization of solid waste and efficient use of natural resources directly contribute to achieving Sustainable Development Goals (SDGs) No. 11 "Sustainable Cities and Communities" and No. 12 "Responsible Consumption and Production." This study aims to determine the optimal substitution ratio of sand with treated granular rubber (TGR) and subsequently evaluate the effect of replacing cement with waste glass powder (WGP) on the physical and mechanical properties of concrete. The experimental methodology followed two phases: First, fine aggregate was replaced with TGR at 2.5%, 5%, 7.5%, and 10% to identify the best-performing mixture. Second, using the optimal TGR proportion, cement was partially substituted with WGP at 4%, 10%, 16%, and 22%. Nine mix designs were prepared, totaling 180 specimens, with evaluations of workability, fresh density, temperature, air content, compressive strength, flexural strength, and modulus of elasticity at 7, 14, and 28 days of curing. Results indicate that TGR-modified concrete exhibited reduced density and improved workability, a trend that reversed in hybrid mixtures combining optimal TGR dosage with WGP as partial cement replacement. The 2.5% TGR + 16% WGP hybrid combination achieved mechanical performance improvements up to 54.76%, demonstrating viability for non-structural applications while promoting sustainable development through waste valorization.
