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Improved adsorption of the toxic herbicide diuron using activated carbon obtained from residual cassava biomass (manihot esculenta)
No full textThe production and consumption of cassava (Manihot esculenta) occur in several places worldwide, producing large volumes of waste, mostly in the form of bark. This study sought to bring a new purpose to this biomass through producing activated carbon to use as an adsorbent to remove the herbicide Diuron from water. It was observed that the carbon contains the functional groups of methyl, carbonyl, and hydroxyl in a strongly amorphous structure. The activated carbon had a surface area of 613.7 m2 g−1, a pore volume of 0.337 cm3 g−1, and a pore diameter of 1.18 nm. The Freundlich model was found to best describe the experimental data. It was observed that an increase in temperature favored adsorption, reaching a maximum experimental capacity of 222 mg g−1 at 328 K. The thermodynamic parameters showed that the adsorption was spontaneous, favorable, and endothermic. The enthalpy of adsorption magnitude was consistent with physical adsorption. Equilibrium was attained within 120 min. The linear driving force (LDF) model provided a strong statistical match to the kinetic curves. Diffusivity (Ds) and the model coefficient (KLDF) both increased with a rise in herbicide concentration. The adsorbent removed up to 68% of pollutants in a simulated effluent containing different herbicides. Activated carbon with zinc chloride (ZnCl2), produced from leftover cassava husks, was shown to be a viable alternative as an adsorbent for the treatment of effluents containing not only the herbicide Diuron but also a mixture of other herbicides
Some new classes of degenerated generalized apostol-bernoulli, apostol-euler and apostol-genocchi polynomials
No full textThe aim of this paper is to study new classes of degenerated generalized Apostol-Bernoulli, Apostol-Euler and Apostol-Genocchi polynomials of order α and level m in the variable x. Here the degenerate polynomials are a natural extension of the classic polynomials. In more detail, we derive their explicit expressions, recurrence relations and some identities involving those polynomials and numbers. Most of the results are proved by using generating function methods
Active disturbance rejection control for robot manipulator
No full textActive Disturbance Rejection Control (ADRC) is a control methodology used in chemical processes, aircraft, motors, and other systems. This paper compares the results of an ADRC controller to a Proportional Integral Derivative controller (PID), applied to two degrees of freedom robots. A Linear Extended State Observer (LESO) is used to reconstruct the state variables and unknown parameters needed to control the position of each link. The ADRC can achieve the tracking position and estimate the velocity of each link. The results of the simulation program are shown
Distribution of Miathyria marcella larvae (Odonata: Libellulidae) and water quality of wetlands in Northern Colombia
No full textThis study aims to assess the physicochemical characteristics regulating the distribution and abundance of M. marcella larvae in six wetlands in the northern Colombia. Standardized techniques for collecting invertebrate and physicochemical data were used in 29 sampling points in an intraannual period. Mean pH and temperature oscillated in narrow ranges within wetlands (7.7 ± 0.09–8.6 ± 0.07; 28.1 ± 0.29–32.8 ± 0.17 °C, respectively), whereas ammonium concentrations and conductivity exhibited a wide variation (0.2 ± 0.03–2.8 ± 0.54 mg NH4 L−1; 861 ± 30.7–19254 ± 1706 µS cm−1, respectively). A total of 2586 individual M. marcella larvae were collected. Abundance was greater in wetlands influenced by the Magdalena River, with 19.4 ± 1.7 and 9.3 ± 1.4 individuals; followed by wetlands hydrologically influenced by seasonal runoff, with 8.1 ± 0.4 and 6.4 ± 0.4 individuals; and lowest in wetlands with influence of the Caribbean Sea, with 3.9 ± 0.3 and 0.3 ± 0.1 individuals. Abundances of M. marcella larvae exhibited similar variations at different months during the sampling period. Abundance and distribution of M. marcella larvae in wetlands of northern Colombia is strongly dependent on water conductivity, transparency and alkalinity. This study evidence that Odonata larvae are a valuable tool as bioindicators for wetland assessment and monitoring
Bibliometric analysis of the potential of technologies in the humanitarian supply Chain
No full textThis study presents a bibliometric analysis of research on technology in the humanitarian supply chain. The methodology includes performance analysis and science mapping to explore the application of technologies in humanitarian supply chains. This paper contributes to the literature by examining the most influential authors, trends, journals, countries, institutions, and the recent humanitarian supply chain collaboration. The information presented in this research was obtained with the Scopus database. The study identified 342 documents after applying filters to screen for duplicates and manuscripts unrelated to the topic. The articles were analyzed using MS Excel and VOSviewer. The research provides an overview of state of the art showing a high collaboration between the authors Ramesh A. and Kabra C, and the most relevant institutions were the Griffith Business School and the Delft University of Technology. Journal of Humanitarian Logistics and Supply Chain Management and Journal of Disaster Research were the most productive journals. The terms analysis shows that “disasters”, “disaster prevention”, “humanitarian logistics”, and “human” are the most used keywords. The study identifies future research lines related to the interaction between critical technologies to deliver real benefits to the humanitarian supply chain. As a result, it proposes integrating the significant contributions of new technologies, such as blockchain, big data, artificial intelligence, 3D printing, virtual and augmented reality, and the social media relief phase following the disaster. It also indicates gaps in knowledge in terms of research related to human-made disasters and health emergencies
Protection of human rights and barriers for people with hiv/aids in Colombia: an analysis of the legal framework
No full textPeople living with HIV/AIDS not only suffer in terms of physical and/or psychological health, but also frequently experience violations of human rights and fundamental freedoms. Although there are international treaties and a regulatory framework that legally protects people with HIV/AIDS, it is essential to determine the effectiveness of the regulatory framework in Colombia. Therefore, our main goal was to examine the legislation on HIV/AIDS in Colombia with the purpose of understanding the decrees and laws, and describing the main obstacles and barriers that people with HIV/AIDS encounter. For this purpose, we employed the method of legal interpretation and reviewed the legal regulations on HIV/AIDS, as well as the judgments of guardianship of the Constitutional Court. It is verified that there is a specific regulation on HIV/AIDS, specifically decree 559 of 19,991, decree 1543 of 1997, Law 599 of 2000, Law 972 of 2005, and Law 1220 of 2008. Although at the legislative level Colombia shows an evolution in the norm, patients with HIV/AIDS continue to be victims of human rights violations. As a result, and through the analysis of tutela judgments, it was found that the Constitutional Court recognized the violation of rights and ordered the necessary measures to be taken to guarantee the human rights and fundamental freedoms of the defendants
Nutritional and exercise interventions in cancer-related cachexia: an extensive narrative review
No full textOne of the common traits found in cancer patients is malnutrition and cachexia, which affects between 25% to 60% of the patients, depending on the type of cancer, diagnosis, and treatment. Given the lack of current effective pharmacological solutions for low muscle mass and sarcopenia, holistic interventions are essential to patient care, as well as exercise and nutrition. Thus, the present narrative review aimed to analyze the nutritional, pharmacological, ergonutritional, and physical exercise strategies in cancer-related cachexia. The integration of multidisciplinary interventions could help to improve the final intervention in patients, improving their prognosis, quality of life, and life expectancy. To reach these aims, an extensive narrative review was conducted. The databases used were MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. Cancer-related cachexia is a complex multifactorial phenomenon in which systemic inflammation plays a key role in the development and maintenance of the symptomatology. Pharmacological interventions seem to produce a positive effect on inflammatory state and cachexia. Nutritional interventions are focused on a high-energy diet with high-density foods and the supplementation with antioxidants, while physical activity is focused on strength-based training. The implementation of multidisciplinary non-pharmacological interventions in cancer-related cachexia could be an important tool to improve traditional treatments and improve patients’ quality of life
Bibliometric analysis on Behavioral Economics: period 2000-2020
No full textLa presente investigación tiene como objetivo describir las principales características de construir una estructura intelectual bibliográfica de la producción científica mundial relacionada con el comportamiento económico en los campos de economía, administración y negocios, a partir de un análisis descriptivo de la estructura, contenido y evolución. La metodología corresponde a un análisis bibliométrico de literatura de la principal base de datos científica Web of Science, utilizando software especializado y programación en R. Se construyó una base de datos con 12,668 artículos relacionados con las frases "comportamiento económico" y “economía del comportamiento” desde el año 2000 al 2020. El análisis mostró cierta correlación entre ambas búsquedas, aunque no completa, por lo cual se muestra la importancia de delimitar correctamente los parámetros bibliométricos.The purpose of this research is to describe the main characteristics and steps about how elaborate an intellectual bibliography of global academic production related to the topic “economic behavior” in economy, business administration and management, making a descriptive analysis of the structure, intellectual contain and development. Methodology consisted in a bibliometric analysis of the science database Web of Science, using R, a mathematic and statistic software. A database was built with 12,668 articles related to “economic behavior” and “behavioral economy” from 2000 to 2020. Data analysis revealed a level of correlation between both searches, nevertheless, this was not an absolute correlation, which highlight the importance of a good delimitation of bibliometric parameters
Education, research, and development expenditure is the best way to competitiveness—a panel data approach for Latin American Countries
No full textThis paper investigates the impact of variations in Research and Development Spending and Education Expenditure on GDP variations in Latin America during the period between 2000 and 2019 (20 years). The dependent variable for productivity and competitiveness is the Gross Domestic Product GDP per capita adjusted for purchasing power parity. GDP per capita, the broadest measure of national productivity, is closely linked over time to a nation's standard of living. The econometric model proposed uses the Prais-Winsten methodology and corrected standard errors and first-order autocorrelation correction. We concluded that the variations in spending on education and research and development have a significant and direct effect on the competitiveness and productivity represented in the analyzed GDP. Therefore, the Latin American countries studied (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Mexico, Paraguay, Peru, and Uruguay) are recommended to invest in education, research, and development, not only as a government effort but also as a policy of all sectors. This paper represents a methodological novelty and suggests directions for national systemic competitiveness policies
Limitations for student participation in research seedbeds
No full textIntroducción: Los Semilleros de Investigación-SI son una estrategia orientada a la consolidación de entramados entre docentes-investigación-estudiantes, en búsqueda de una educación de calidad. Sin embargo, en el contexto empírico de la presente investigación, representado por un programa académico de una Institución de Educación Superior-IES colombiana, se perciben tasas bajas de participación en actividades de investigación, evidenciando la existencia de restricciones y obstáculos en la dinámica de los colectivos interactuantes. Objetivo: Caracterizar los factores que limitan la participación de los estudiantes en los SI. Metodología: El diseño de la investigación es no experimental, de alcance descriptivo y enfoque mixto, pues se aplicaron entrevistas y encuestas a la comunidad académica involucrada, es decir, estudiantes, docentes y directivos de la IES. El procesamiento de los datos estuvo a cargo de los Software Excel y Atlas.ti. Resultados y discusión: Los estudiantes reconocen la importancia y valor agregado de los SI, sin embargo, poseen imaginarios erróneos en torno a su participación, así mismo expresan ciertos niveles de exclusión en los procesos de vinculación. Por su parte, los docentes y directivos enuncian ausencia de vocación y compromiso de los estudiantes, y, debilidades institucionales en la política de investigación. Conclusiones: La IES y el programa deben fortalecerse en dos dimensiones básicas: la construcción de tejido institucional, fortaleciendo la triada estudiantes-investigación-docente, para lo cual es indispensable procesos de formación permanente; y, además, forjar políticas institucionales que sirvan como brújula en la construcción del prenombrado tejido, garantizando articulación y sinergia entre los actores.Introduction: The Research Seedbeds-SI are a strategy aimed at consolidating networks between teachers-research-students, in search of quality education. However, in the empirical context of this research, represented by an academic program of a Colombian Higher Education Institution-HEI, low rates of participation in research activities are perceived, evidencing the existence of restrictions and obstacles in the dynamics of interacting groups. Objective: To characterize the factors that limit the active participation of the students in the IS. Methodology: The research design is non-experimental, with a descriptive scope and a mixed approach, since interviews and surveys were applied to the academic community involved, that is, students, teachers and directors of the HEI. The processing of the data was in charge of the software excel and Atlas.ti. Results and discussion: The students recognize the importance and added value of the IS, however, they have erroneous imaginaries around their participation, they also express certain levels of exclusion in the bonding processes. For their part, the teachers and directors state the absence of vocation and commitment of the students, and institutional weaknesses in the research policy. Conclusions: The IES and the program must be strengthened in two basic dimensions: the construction of an institutional fabric, strengthening the triad students-research-teacher, for which permanent training processes are essential; and, in addition, to forge institutional policies that serve as a compass in the construction of the aforementioned fabric, guaranteeing articulation and synergy between the actors