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A statistical physics approach to understanding the adsorption of methylene blue onto cobalt oxide nanoparticles
No full textThe production of cobalt oxide nanoparticles and their use in the adsorption of methylene blue (MB) from solution is described in the paper. The X-ray diffraction patterns show that the synthesized cobalt oxide nanoparticles have a crystalline cubic structure. The study of the adsorption of methylene blue onto the cobalt oxide nanoparticles involved determining the contact time and initial concentration of the adsorption of MB on the adsorbent. The kinetics of adsorption were analyzed using two kinetic models (pseudo-first order and pseudo-second order), and the pseudo-second-order model was found to be the most appropriate for describing the behavior of the adsorption. This study indicates that the MLTS (monolayer with the same number of molecules per site) model is the most suitable model for describing methylene blue/cobalt oxide systems, and the parameter values help to further understand the adsorption process with the steric parameters. Indicating that methylene blue is horizontally adsorbed onto the surface of the cobalt oxide, which is bonded to two different receptor sites. Regarding the temperature effect, it was found that the adsorption capacity increased, with the experimental value ranging from 313.7 to 405.3 mg g−1, while the MLTS predicted 313.32 and 408.16 mg g−1. From the thermodynamic functions, high entropy was found around 280 mg L−1 concentration. For all concentrations and temperatures examined, the Gibbs free energy and enthalpy of adsorption were found to be negative and positive, respectively, suggesting that the system is spontaneous and endothermic. According to this study’s findings, methylene blue adsorption onto cobalt oxide nanoparticles happens via the creation of a monolayer, in which the same amount of molecules are adsorbed at two distinct locations. The findings shed light on the methylene blue adsorption process onto cobalt oxide nanoparticles, which have a variety of uses, including the remediation of wastewater
A multilayer adsorption of perfluorohexanesulfonic and perfluorobutanesulfonic acids on bio-based polyurethane/chitosan foam: Advanced interpretation of the adsorption mechanism
No full textThis work presents an application of a multilayer model derived from statistical physics to the adsorption experimental data of two industrial pollutants, namely perfluorohexanesulfonic (PFHxS) and Perfluorobutanesulfonic (PFBS) acids on a bio–based polyurethane /chitosan(PU/CH) adsorbent foam, at T = 298–328 K and pH 4. This model shows that the number of PFHxS and PFBS layers formed on adsorbent surface increases from 1.61 to 3.80, and from 1.56 to 2.26 respectively by increasing the temperature.This means that the adsorbate molecules are arranged on a variable number of layers. For instance, at 328 K, it was deduced that around 80 % of PFHxS acid was taken up by the PU/CH composite, forming a total of four layers, whereas the remaining 20 % contributed to the formation of three layers. The estimation and analysis of the number of molecules bound per active site is useful to understand the adsorption mechanism. PFHxS and PFBS adsorb on PU/CH in non-parallel configuration, through a multimolecular docking characterized by more than one molecule per active site. The PU/CH performances are investigated in terms of the maximum adsorption capacity of both the tested industrial pollutants, retrieving similar values for both PFHxS and PFBS. Two adsorption energies are calculated showing that physical forces are contributing to remove these pollutants. Interstingly, thermodynamic calculations are also introduced and interpreted to understand the adsorption mechanism at macroscopic level. These theoretical scientific evidences provide a plausible explanation of the PFHxS and PFBS adsorption mechanisms and contribute to understand this interfacial process at the molecular level
A preliminary risk assessment in naval Antarctic expeditions
No full textIn this work to implement the Risicar methodology and propose a risk overview to facilitate and encourage traveling in a Ship to the Antarctic continent to carry out scientific expeditions would use this method to treat possible risks to which they may be exposed. The results of this method were determinates the possible risks of these expeditions were identified and classified, evaluated, and treated, facilitating the risk management of the deck operations
Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the global burden of disease study 2021
No full textBackground: Future trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050. Methods: Using forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline. Findings: In the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]). Interpretation: Globally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions. Funding: Bill & Melinda Gates Foundation
Exploring the landscape of eco-innovation: a bibliometric analysis of concepts and trends in the manufacturing and shipbuilding industries
No full textEco-innovation (EI) as a conceptual approach has gained significant momentum in the transition of the manufacturing sector towards sustainability. This paper aims to contribute to the study of the research landscape on EI in the manufacturing industry by applying a bibliometric methodology and identifying prevailing trends and concepts used in academic literature. For this purpose, search engines such as Scopus and Web of Science (WoS) were utilized, along with analytical tools such as Bibliometrix, Microsoft Excel, and Gephi. The search was conducted using equations constructed from keywords deemed relevant to the objective, and the records obtained from the databases were consolidated into a single repository for joint analysis using the RStudio platform. The findings revealed an increase in scientific production from 2010 onwards. The analysis identified that the most influential authors, affiliations, and documents primarily originate from Spain, Germany, and China. The key concepts identified are the circular economy, eco-design, and green technologies, which provide a holistic framework for improving efficiency, reducing waste, and mitigating environmental impacts. EI promotes close collaboration between industries to reduce the ecological footprint. Nonetheless, there is a notable gap in research about EI in the shipbuilding industry, necessitating further exploration in the sector. This study lays a foundation for future investigations in this evolving domain
Aprendizaje cooperativo como estrategia de mediación didáctica para el fortalecimiento de la resolución de problemas matemáticos en la multiplicación en estudiantes de básica primaria
No full textLa resolución de problemas en el área de matemáticas ha cobrado relevancia en el contexto, especialmente porque a través de ésta se forjan habilidades necesarias para afrontar los acontecimientos cotidianos. La investigación tiene como objetivo Implementar el aprendizaje cooperativo como estrategia de aprendizaje en la resolución de problemas matemáticos con la multiplicación en estudiantes de 3° en la Institución Educativa Centro Docente Nuestra Señora Del Buen Consejo. Se indagaron las variables: resolución de problemas matemáticos y estrategia de aprendizaje cooperativo. El enfoque es cuantitativo, paradigma empírico-inductivo y diseño preexperimental. Se contó con una muestra conformada por 15 estudiantes de grado 3° del Centro Docente Nuestra Señora Del Buen Concejo, con un rango de edades entre los 8 y 9 años. Por consiguiente, en esta investigación se utilizan técnicas e instrumentos acordes al paradigma en donde se implementó el pre-test, posteriormente talleres de intervención y finalmente el posttest. Los resultados permitieron dar respuesta a la pregunta de investigación y afirmar la hipótesis planteada que el aprendizaje cooperativo como estrategia didáctica SI fortalece la competencia de resolución de problemas matemáticos en la multiplicación al incrementar sus resultados después de la intervención.Problem solving in the area of mathematics has become relevant in the context, especially because through it the necessary skills are forged to face everyday events. The objective of the research is to implement cooperative learning as a learning strategy in solving mathematical problems with multiplication in third grade students at the Nuestra Señora Del Buen Consejo Teaching Center Educational Institution. The variables were investigated: mathematical problem solving and cooperative learning strategy. The approach is quantitative, empirical-inductive paradigm and pre-experimental design. There was a sample made up of fifteen third grade students from the Nuestra Señora Del Buen Concejo Teaching Center, with an age range between 8 and 9 years old. Therefore, in this research, techniques and instruments are used according to the paradigm where the pre-test was implemented, later intervention workshops and finally the post-test. The results allowed us to answer the research question and affirm the hypothesis that cooperative learning as a didactic strategy DOES strengthen the competence of solving mathematical problems in multiplication by increasing its results after the intervention.Lista de tablas 7 -- Lista de figuras 9 -- Introducción 11 -- Capítulo I 14 -- Planteamiento del problema 14 -- Descripción del problema 14 -- Formulación del problema 21 -- Objetivos 22 -- Objetivo general 22 -- Objetivos específicos 22 -- Hipótesis 23 -- Hipótesis positiva 23 -- Hipótesis negativa 23 -- Justificación 24 -- Delimitación de la investigación 27 -- Capitulo II 28 -- Marco Referencial 28 -- Estado del arte 28 -- Resolución de problemas 28 -- Ámbito internacional 28 -- Ámbito nacional 31 -- Ámbito local 34 -- Aprendizaje cooperativo 38 -- Ámbito internacional 38 -- Ámbito nacional 41 -- Ámbito local 44 -- Marco teórico 47 -- Aprendizaje cooperativo 47 -- Resolución de problema 51 -- Marco conceptual 54 -- Resolución de problemas matemáticos 54 -- Razonamiento y argumentación 54 -- Planteamiento y resolución problemas 54 -- Competencias matemáticas 55 -- Método 55 -- Operaciones matemáticas 56 -- Aprendizaje cooperativo 56 -- Relaciones interpersonales 57 -- Comunicación 57 -- Aulas Heterogéneas 58 -- Inteligencias múltiples 58 -- Marco legal 59 -- Matriz de las variables 60 -- Capítulo III 58 -- Metodología 58 -- Paradigma 58 -- Enfoque 59 -- Diseño 61 -- Población y muestra 62 -- Técnicas e instrumentos de investigación 63 -- Fases de la investigación 66 -- Capitulo IV 68 -- Análisis e interpretación de resultados 68 -- Confiabilidad del cuestionario 68 -- Alpha de Cronbach 69 -- Fiabilidad 70 -- Escala: ALL VARIABLES 71 -- Caracterización: Desempeño de los estudiantes 3° en la resolución de problemas matemáticos con la multiplicación 73 -- Acciones contribuyentes al fortalecimiento en la resolución de problemas matemáticos 75 -- Análisis sobre aprendizaje cooperativo como estrategia didáctica para el fortalecimiento en la resolución de problemas matemáticos 102 -- Triangulación 113 -- Recomendaciones 119 -- Referencias 120
Anexos 132licenciado(a) en Educación Básica PrimariaPregrad
Exploring innovation capabilities in organizations through a scientometric approach in the context of manufacturing industry
No full textOver the last four decades, innovation capability has been studied to examine the innovation phenomenon based on the specific characteristics of organizations and systems under the theory of resources and capabilities. However, "capability" has diverse applications, and its correlation with innovation remains unclear. This study aims to clarify the definition of "innovation capability" in the context of the manufacturing industry and to comprehend how researchers presently investigate this concept. In order to meet this, an exhaustive search was conducted in the Scopus and Web of Science (WoS) databases, covering the period from 2018 to 2023. The selection of documents for analysis was determined by applying the scientometric method. The authors of this research identified 462 documents, and the bibliometric analysis, conducted using VOS viewer and Bibliometrix tools, revealed four main thematic areas within the research domain: sustainability, business performance, technology transfer, and knowledge management. As a result, this study identified the seminal authors of the concept. It provided a precise definition of "innovation capability", highlighting the significant interest that this research topic arouses in current academic literature
Evaluación del índice de vegetación de diferencia normalizada en la cuenca del rio fonce considerando factores tales como la condición meteorológica y topografía
No full textThis research evaluates the Normalized Difference Vegetation Index (NDVI) in the Fonce River basin, located in Santander, Colombia, considering hydrological and topographical factors. In the study, the river’s basin was delineated using topographic satellite images to define the study area. Subsequently, eight active meteorological stations of the Institute of Hydrology, Meteorology, and Environmental Studies (IDEAM) were identified, providing the necessary hydrometeorological information for the research. Based on the collected data, a detailed analysis was conducted, and representative dates within the study period, spanning from 2000 to 2023, were selected. These dates encompassed various hydrometeorological conditions, such as wet periods, dry periods, and times with antecedent wet and dry conditions. Then, using MOD13Q1 satellite images, the NDVI was calculated for each of these dates, allowing for a detailed assessment of vegetation variation in response to the different hydrological and topographic conditions present in the basinLa presente investigación evalúa el Índice de Vegetación de Diferencia Normalizada (NDVI) en la cuenca del río Fonce, ubicado en el Departamento de Santander-Colombia, considerando factores hidrológicos y topográficos. En la investigación se delimitó la cuenca del río Fonce a partir de información topográfica satelital para definir el área de estudio. Posteriormente, se identificaron ocho estaciones meteorológicas activas del Instituto de Hidrología, Meteorología y Estudios Ambientales (IDEAM) que proporcionaron la información de registros de precipitaciones necesarios para la investigación. A partir de los datos recopilados, se realizó un análisis detallado y se seleccionaron fechas representativas dentro del período de estudio, que comprende los años entre 2000 y 2023, abarcando diversas condiciones hidrometeorológicas, como periodos húmedos, períodos secos, épocas con condiciones antecedente húmedas y de condición antecedente seca. Luego, utilizando imágenes satelitales del tipo MOD13Q1, se calculó el NDVI para cada una de estas fechas, lo que permitió una evaluación detallada de la variación de la vegetación en respuesta a las distintas condiciones hidrológicas y topográficas presentes en la cuenca.Listado de tablas y figuras 10 – Figuras 10 –Tablas 12 -- Introducción 13 --Planteamiento del problema 15 –Justificación 17 -- Objetivos 19 -- Objetivo General 19 -- Objetivos Específicos 19 – Alcance 20 – Limitaciones 21 --Fundamentos teóricos 22 -- Marco teórico de referencia 22 -- Teledetección. 22 -- Imágenes satelitales MODIS 24 -- Índice de vegetación de diferencia normalizada. 25 -- Usos del índice de vegetación de diferencia normalizada 26 -- Generalidades de la cuenca 27 – Cartografía 28 -- Hidrografía. 28 -- Clima. 29 -- Investigaciones antecedentes 30 -- Estado del arte. 30 --Metodología 35 -- Delimitación de la cuenca hidrográfica 36 --Identificación de estaciones pluviométricas 36 -- Análisis pluviométrico y selección de fechas de interés 36 -- Descarga de imágenes satelitales 37 -- Cálculo de NDVI 37 -- Resultados y discusión 38 -- Análisis hidrológico 38 -- Delimitación de la cuenca. 38 -- Selección de estaciones IDEAM. 39 -- Procesamiento de información pluviométrica 41 -- Selección de las fechas de interés. 45 -- Cálculo de NDVI 46 -- Correlación entre el NDVI y Precipitación 58 -- NDVI vs Precipitación total mensual 59 -- Evaluación de otras condiciones hidrológicas. 60 -- Análisis de condiciones topográficas 64 -- Conclusiones 70 -- Influencia de la Precipitación en el NDVI 70 -- Influencia de la Topografía en el NDVI 71 – Recomendaciones 72 –Referencias 73Ingeniero(a) CivilPregrad
Determination of the level of financial organization through a multiple regression model of entrepreneurs in Barranquilla, Colombia
No full textThe present study focuses on determining the level of financial organization of Barranquilla entrepreneurs through a multiple regression model. To develop this study, a field collection process based on the quantitative approach is used, applying a survey of 35 Likert scale items to a total of 305 entrepreneurs from the city of Barranquilla-Colombia. The results of the multiple linear regression model are suitable for predicting the behavior of finances based on independent factors: Recognize your balance point, design a budget that supports decision making in the business, maintain an organized record of your sales, the sales price of its products is found from validated profit calculations, operational expenses are directly related to the main purpose of the business, the level of debt does not put the operation of the business at risk, it complies with all tax obligations, and for the organization of its accounting operations it has software. It is concluded that these independent factors are predictive of financial behavior, highlighting the importance of improving the financial organization of local entrepreneurs to boost economic growth in the region.El presente estudio se centra en la determinación del nivel de organización financiera de los emprendedores barranquilleros a través de un modelo de regresión múltiple. Para desarrollar el presente estudio se emplea un proceso de recolección de campo basado en el enfoque cuantitativo, aplicando una encuesta de 35 ítems de escala Likert a un total de 305 emprendedores de la ciudad de Barranquilla-Colombia. Los resultados del modelo de regresión lineal múltiple resultan adecuados para predecir el comportamiento de las finanzas a partir de los factores independientes: Reconoce su punto de equilibrio, diseña un presupuesto que apoya la toma de decisiones en el negocio, mantiene un registro organizado de sus ventas, el precio de venta de sus productos es hallado a partir de cálculos de utilidad validados, los gastos operacionales se relacionan directamente con el objeto principal del negocio, el nivel de endeudamiento no pone en riesgo la operación del negocio, cumple con todas las obligaciones tributarias, y para la organización de sus operaciones contables cuenta con un software. Se concluye que estos factores independientes son predictivos del comportamiento financiero, destacando la importancia de mejorar la organización financiera de los emprendedores locales para impulsar el crecimiento económico en la región
Examining educational pathways: mathematics licensure training
No full textThe study investigated the educational preparedness of prospective mathematics teachers in Barranquilla and Cartagena, Colombia, by examining the socio-demographic characteristics and educational experiences of 57 participants enrolled in three distinct undergraduate teaching programs. The research employed a quantitative approach with a cross-sectional survey design, utilizing structured questionnaires to assess participants’ perceptions of their readiness across various domains, including school mathematics, advanced mathematics, pedagogy, and math didactics. The study aimed to uncover nuanced differences in the educational trajectories and perceived preparedness of future educators within the context of the Caribbean region. The hypothesis guiding the research posited that exploring the educational environment (EE) provided to pre-service teachers could offer valuable insights into how regional teacher education institutions approach the development and competency of mathematics educators. The study sought to validate this hypothesis by conducting a comparative analysis of knowledge domains and educational methods between the two cities. Statistical analyses revealed notable variations in knowledge domains between Barranquilla and Cartagena. Consistent disparities were observed in Fundamental Mathematics, with Barranquilla participants scoring significantly higher (M = 3.8, SD = 0.6) compared to their Cartagena counterparts (M = 3.2, SD = 0.5), p = 0.012. Similar trends were found in Higher Mathematics and Educational Methods, with p-values of 0.027 and 0.041, respectively. These findings contribute to the broader discourse on the effectiveness of teacher education programs in the Caribbean region, highlighting the need for targeted interventions and enhancements in teacher training programs to address the observed disparities and improve mathematics education in urban areas