Producción científica y académica

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Evaluación de la contaminación por aluminio del agua para consumo humano, región central de Colombia

Ospina, Oscar Efrén | 2021

Introducción— El aluminio se incorpora al agua de manera natural y/o antrópica, con niveles de riesgo para la salud por encima de 0.2 mg/L según la normativa colombiana. Puede surgir como contaminante emergente al utilizarse inadecuadamente coagulantes de sales de aluminio en la clarificación del agua potable. Objetivo— Evaluar la contaminación por aluminio del agua para consumo humano de la región central de Colombia, determinando su potencial origen y cumplimiento de la normativa vigente. Metodología— La investigación de carácter exploratorio, analizó la presencia de aluminio en agua cruda y tratada durante el período 2007–2018, mediante muestras y ensayos de laboratorio, así como la evaluación hidráulica y de operación de plantas de tratamiento de agua, en municipios de los departamentos de Tolima y Cundinamarca, región central de Colombia. Resultados— En más del 30% de los municipios evaluados se evidenció la presencia de aluminio en el agua para consumo humano, por encima del máximo permitido por la normativa vigente. En varios casos se debió a deficiencias en el proceso de tratamiento donde se utilizan sales de aluminio para la coagulación, sin dosificación adecuada como ocurrió en el municipio de Melgar, o por altas concentraciones presentes en las fuentes hídricas de abastecimiento, como es el caso del río Magdalena en la región central de Colombia. Conclusiones— El aluminio en agua para consumo humano, se da por su presencia en fuentes hídricas y producto de deficiencias hidráulicas y operativas en el proceso de clarificación de las plantas de tratamiento donde se usa sulfato de aluminio como coagulante, por inadecuada aplicación de dosis óptimas, deficiente intensidad de agitación y de gradientes de velocidad en mezcla rápida y floculación, tiempos de floculación y sedimentación fuera del rango óptimo.

Environmentally sustainable universities: the Nueva Granada Campus of the Nueva Granada Military University and its relationship with water

Ivanova, Yulia | 2021

Introducción— La sede campus Nueva Granada de la Universidad Militar Nueva Granada (Colombia) se construyó respondiendo a las tendencias globales de la arquitectura moderna para estar en armonía con el ambiente a través de sus construcciones bioclimáticas, iluminación con base en energía fotovoltaica y manejo del recurso hídrico. No obstante, el constante crecimiento de la oferta académica, de la infraestructura y de la comunidad universitaria demanda un mayor uso de los recursos naturales, indispensables para un buen funcionamiento de la sede. Uno de estos recursos es el agua. Objetivo— En el trabajo se evaluó la sustentabilidad del manejo del agua en la sede Campus de la universidad. Metodología— Esta evaluación se realizó empleando el Índice de Sustentabilidad del Recurso Hídrico con la integración del concepto de la huella hídrica. Resultados— Se obtuvo que la universidad ha hecho unos esfuerzos para el manejo eficiente del recurso hídrico. No obstante, estos no son suficientes para evaluar el manejo del agua como sustentable. Conclusiones— Teniendo en cuenta este resultado se concluye que la universidad debe formular acciones de mejora en los aspectos tecnológico y gestión institucional que permitirán mantener los consumos del agua estables bajo el escenario del crecimiento de la universidad, disminuirán la contaminación de los vertimientos e impactarán de manera positiva la evapotranspiración, como parte fundamental del retorno del agua al ambiente.

Physicochemical and functional characterization of trupillo flour (Prosopis juliflora (Sw.) DC) and its inclusion in a food matrix

Franco Sarmiento, Andrea Carolina | 2021

Introduction— The high protein content has made legumes a raw material of interest in the formulation of different agroindustrial products; the trupillo (Prosopis juliflora) tree is an easily accessible, multipurpose, wild legume that can be used in all its composition, has a high protein value and little commercial level, which is currently being wasted as it is mistakenly considered a weed and that It could be seen as a new alternative that helps in the potentialization of the food sector. Objective— This research aims to functionally characterize trupillo flour (Prosopis juliflora), obtained from leaves and seeds, to include it in a food matrix as a protein extender. Methodology— The experimental design for this research required three phases, i) obtaining, bromatological and functional characterization of leaf flour and trupillo seeds, ii) standardization of formulations for artisan sausages using trupillo flour as a protein source, and iii) bromatological and sensory characterization of the processed sausages. Results— It was found that the flours obtained preserved the characteristic odor and color of each raw material. Particularly, the seed flour presented bromatologically and functionally better protein contents (27.7%), ash (8.04%), swelling capacity (16.7 ml water / g sample), water absorption (7.89 g water / g sample) and water retention capacity (27.9 g water/g sample), for which it was selected to be included in the sausages. In the three formulations made (C, CT and T), there were variations in the color and texture of the sausages, with Formulation T standing out for presenting higher protein content (13.7%). However, consumers preferred Formulation C. Conclusions— These results allow to propose the inclusion of sausage with trupillo flour in the human diet as an alternative to traditional products.

Mitigation of nonlinear effects using machine learning in coherent optical access networks

Escobar, Alejandro | 2021

Introduction— The use of coherent detection jointly with high-level modulation formats such as 16 and 64-QAM seems to be a convenient strategy to increment capacity of future optical access networks. However, coherent detection requires high complexity digital signal processing to mitigate different impairments. Objective— Mitigate signal distortions using nonsymmetrical demodulation techniques based on Machine Learning (ML) algorithms. Methodology— First, a single channel Nyquist m-QAM system at 28 and 32 Gbps was simulated in VPIDesignSuite software. Then, different signals modulated at 16 and 64-QAM were generated with different laser linewidth, transmission distances and launch powers. Two ML algorithms were implemented to carry out the demodulation of the generated signals. The performance of the algorithms was evaluated using the Bit Error Rate (BER) in terms of different system parameters as laser linewidth, transmission distance, launch power and modulation format. Results— The use of ML allowed gains up to 2 dB in terms of optical signal-to-noise ratio at a BER value of for 16-QAM and 1.5 dB for 64-QAM. Also, the use of ML showed that it is possible to use a lower cost laser (100 kHz linewidth vs 25 kHz) with a better BER performance than using conventional demodulation. Conclusions— We showed that the use of both algorithms could mitigate nonlinear effects and could reduce computational complexity for future optical access networks.

Comparative-experimental study of different roof types in a tropical climate

Tschiersch, Kim-Christin | 2021

Introduction— The implementation of green roofs in buildings has become increasingly common, because it is an ecological construction alternative that provides great benefits, which range from reducing air pollution to improving air conditioning inside of the buildings. Objective— This article aims to evaluate whether extensive green roofs are an energy-valuable option in a tropical climate compared to a thermoacoustic, clay tile, and concrete roof. Methodology— An experimental study was carried out in summer (December) in a tropical climate, where the internal temperature of two identical small buildings was compared except for the roof type. Both small buildings were built with a low construction standard according to buildings of families with low income in this region. Data of internal temperatures and other climatic conditions were analyzed to compare the influence of the roof type on the inner shelter temperature. Results— In these experiments, the average inner shelter temperature of green roofs was lower than the same temperature for thermoacoustic, clay tile and concrete roof and resulted in average temperature differences of 1.8°C, 0.9°C and 1.5°C, respectively (depending on environmental conditions). Conclusions— It was possible to show that the green roof has a greater thermal inertia compared to the others. However, the temperature difference between the green roof and the other roof types was in the same range as in studies conducted in other climatic regions, therefore no special benefit of the green roof has been derived in a warm-tropical climate in this study. However, the low building standard can be of great interest for a final evaluation and the authors recommend to conduct further studies.

Tidal energy potential in the center zone of the colombian Pacific coast

Quintero Aguilar, Gabriel Esteban | 2021

Introducción— La energía de las mareas está evidenciando un interés a nivel mundial porque se puede estimar con precisión debido al comportamiento cíclico de las mareas. Esta energía puede extraerse de las diferencias en la altura del nivel del mar mediante el uso de compuertas y turbinas de un embalse (planta de energía mareomotriz), o extraerse de las corrientes de marea a través de una red de microturbinas reversibles de eje horizontal como se propone en este estudio. Así, la región del Pacífico colombiano tiene la oportunidad de implementar microturbinas en áreas estratégicas con el desafío de optimizarlas para extraer energía con alturas de marea locales de hasta 4 m y velocidades de corriente de hasta 1.5 m/s. Objetivo— Calcular los potenciales energéticos de las corrientes de marea en la zona central de la costa pacífica colombiana obtenidos mediante modelado hidrodinámico (Delft3D) validado con información in situ. Metodología— El presente estudio parte del nivel 1 de desarrollo tecnológico (Niveles de desarrollo tecnológico, TRL en inglés) hasta llegar a TRL 2. Luego, la investigación realizó una revisión documental de experiencias nacionales e internacionales relacionadas con la energía mareomotriz, evidenciando la gran oportunidad que tiene Colombia para aprovechar este tipo de energía y sumarnos al creciente interés internacional por el desarrollo de energías limpias y renovables. Además, este estudio caracterizó las alturas de las mareas y realizó cálculos de potenciales energéticos a partir de corrientes de marea en el Pacífico colombiano derivados de modelos hidrodinámicos (Delft3D) validados con datos medidos in situ. Los resultados de este estudio incentivan la aplicación de estas tecnologías en Colombia y representan un aporte al cumplimiento de los Objetivos de Desarrollo Sostenible de la ONU (Energía asequible y no contaminante, ODS 7). Resultados— De los 4 puntos de análisis, el punto B (Buenaventura) registró el mayor potencial acumulado de generación eléctrica por mes (31546.56 Wh/mes). Las alturas máximas de marea en los puntos A, B, C y D durante 2018 fueron de 1.88 m. Además, el rango de velocidad media en los puntos A, B, C y D fue de 0.28 m/s a 0.54 m/s, y la velocidad máxima para estos puntos fue de 0.54 m/s, 0.49 m/s, 0.31 m/s y 0.28 m/s respectivamente. Luego, mediante 5 microturbinas mareales con eje horizontal reversible de 1 m de área de barrido para el punto de mayor potencial (B), es posible generar energía eléctrica para cubrir el consumo eléctrico de una casa, y con 544 microturbinas el consumo de 99 casas. La granja de mareas (544 microturbinas) requeriría un área de 2079.36 m2 (por ejemplo, 45.6 m × 45.6 m) y una profundidad media de 5 m; estos requisitos son factibles de cumplir debido a las características del área de estudio. Conclusiones— Esta investigación determinó el potencial energético de las mareas en la zona central del Pacífico colombiano para 4 puntos de interés, (A, B, C y D) y los mayores potenciales se encontraron en los puntos A y B ubicados en Bahía Málaga y Buenaventura respectivamente. Además, se analizaron las velocidades mínimas, la duración de estas y el régimen de mareas diurno (12 h), y se encontró que los puntos A y B mostraron los tiempos más bajos (1 h y 2 h) de velocidad mínima, evidenciando una capacidad de generación eléctrica diaria de 22 h y 20 h respectivamente. En consideración a los resultados obtenidos, esta investigación muestra la oportunidad de realizar estudios para promover el desarrollo de microturbinas reversibles de eje horizontal para el aprovechamiento de la energía mareomotriz. La energía generada podría ser suministrada a comunidades con dificultades de acceso a la red de distribución eléctrica, lo que reduciría la pobreza y la emisión de Gases de Efecto Invernadero (GEI) por la quema de combustibles fósiles y vegetales (leña).

Chromium and Zinc removal from synthetic industrial wastewater in pilot-scale constructed wetlands planted with Cyperus odoratus L.

de Moya Sánchez, Ángel | 2021

Introducción— Los Humedales Construidos (HC) son una tecnología reconocida para tratar aguas residuales industriales. Objetivo— Remover Cr y Zn del agua residual sintética a través de un sistema piloto de humedales construidos de flujo subsuperficial horizontal. Metodología— El estudio se realizó en la Universidad del Atlántico en Barranquilla (Colombia). Dos contenedores de 0.375 m2 de altura fueron rellenados con grava (~ 10 mm y 40% de porosidad) y una columna de agua de 0.3 m. Uno de los humedales se plantó con Cyperus odoratus L. y otro sin plantas se usó como control. Resultados— La eficiencia de remoción de Cr y Zn en el humedal plantado fue de 93% y 96%, respectivamente y se obtuvo 67% y 98% de remoción en el sistema sin plantar con diferencias estadísticas (P < 0.05). La diferencia observada en la producción de biomasa (0.1 kg/m2 y 0.6 kg m2), estuvo relacionada con el climática estacional que pudo haber favorecido el crecimiento de la planta. C. odoratus alcanzó un Factor de Translocación mayor de 1.5 para Cr y Zn, lo cual fue mayor que el reportado para otras especies de Cyperus. Sin embargo, un factor de bioconcentración >13.6 para Zn y < 7.7 para Cr indicó que C. odoratus es una especie acumuladora de Cr y Zn. Los procesos de sorción de metales en la grava pudieron ocurrir debido a la alta eficiencia de eliminación de Zn en los sistemas no plantados. Conclusiones— C. odoratus podría recomendarse para su uso en tecnología de humedales construidos debido a su capacidad de rápido crecimiento, absorción y translocación de metales pesados.

Product or process innovation? The dilemma for exporting SMEs in emerging economies: the case of the Colombian Caribbean

Chang muñoz, eduardo | 2022

On the path to economic globalisation, companies are constantly facing opportunities and challenges in their pursuit of business survival and continuous improvement. Due to its strategic conception, innovation management seems to generate the transformations required in the current competitive environment. This article seeks to analyse the dilemma faced by small and medium sized exporting enterprises located in a developing country and regarding what to manage first: product or process innovation. The empirical analysis has been performed in the Colombian Caribbean region. The results revealed that companies focus more on process innovation than on product innovation. Similarly, it is concluded that the former precedes the latter.

A literature survey on electrical-current-assisted friction stir welding

Sajed, Moosa | 2023-01-25

Electrical-current-assisted friction stir welding (EA-FSW) is a procedure developed for the joining of similar and dissimilar materials. EA-FSW is a newly invented solid-state process to increase welded components’ efficacy in various applications, such as marine structures. EA-FSW joints have investigated the dissimilar joints on aluminum–magnesium, aluminum–steel, and polymer-to-steel. Similar joints have been performed on aluminum, magnesium, and steel. The main parameters that affect the temperature of the nugget in EA-FSW are electrical current and tool rotational velocity. This review paper presents the fundamental principle of EA-FSW, its processes mechanism, and various types of tools, and discusses the different joints that EA-FSW welded. The effect of electrical current on the quality of similar and dissimilar joints is discussed. The simulation process and detailed modeling of the EA-FSW process are discussed in the last section.

Introducing the effective features using the particle swarm optimization algorithm to increase accuracy in determining the volume percentages of three-phase flows

Chen, Tzu-Chia | 2023-01-11

What is presented in this research is an intelligent system for detecting the volume percentage of three-phase fluids passing through oil pipes. The structure of the detection system consists of an X-ray tube, a Pyrex galss pipe, and two sodium iodide detectors. A three-phase fluid of water, gas, and oil has been simulated inside the pipe in two flow regimes, annular and stratified. Different volume percentages from 10 to 80% are considered for each phase. After producing and emitting X-rays from the source and passing through the pipe containing a three-phase fluid, the intensity of photons is recorded by two detectors. The simulation is introduced by a Monte Carlo N-Particle (MCNP) code. After the implementation of all flow regimes in different volume percentages, the signals recorded by the detectors were recorded and labeled. Three frequency characteristics and five wavelet transform characteristics were extracted from the received signals of each detector, which were collected in a total of 16 characteristics from each test. The feature selection system based on the particle swarm optimization (PSO) algorithm was applied to determine the best combination of extracted features. The result was the introduction of seven features as the best features to determine volume percentages. The introduced characteristics were considered as the input of a Multilayer Perceptron (MLP) neural network, whose structure had seven input neurons (selected characteristics) and two output neurons (volume percentage of gas and water). The highest error obtained in determining volume percentages was equal to 0.13 as MSE, a low error compared with previous works. Using the PSO algorithm to select the most optimal features, the current research’s accuracy in determining volume percentages has significantly increased.

Innovation activities and their impact on product innovation results: evidence from a sectorial study

Chang muñoz, eduardo | 2023

In the current competitive context, innovation has become a necessity, to the point that it seems that no company can survive without developing innovation processes. One of the great concerns of small and medium-sized companies is about the investment of resources in innovation activities and their success. Therefore, this article analyzes the influence of different innovation activities performed by small and medium-sized enterprises (SMEs) of the Colombian Caribbean region on their product innovation outcomes and thereby provides a solid groundwork for the design of innovation strategies. To achieve this objective, a data collection instrument was first validated in 56 SMEs, followed by the application of a reflective measurement model with convergent validity analysis. The results of the model application revealed that investment in Research and Development (R&D) and innovation, knowledge transfer, technology adoption, and financial aspects explain to a greater extent the introduction of new products to the market.

Using ANN and combined capacitive sensors to predict the void fraction for a two-phase homogeneous fluid independent of the liquid phase type

Chen, Tzu-Chia | 2023-03-20

Measuring the void fraction of different multiphase flows in various fields such as gas, oil, chemical, and petrochemical industries is very important. Various methods exist for this purpose. Among these methods, the capacitive sensor has been widely used. The thing that affects the performance of capacitance sensors is fluid properties. For instance, density, pressure, and temperature can cause vast errors in the measurement of the void fraction. A routine calibration, which is very grueling, is one approach to tackling this issue. In the present investigation, an artificial neural network (ANN) was modeled to measure the gas percentage of a two-phase flow regardless of the liquid phase type and changes, without having to recalibrate. For this goal, a new combined capacitance-based sensor was designed. This combined sensor was simulated with COMSOL Multiphysics software. Five different liquids were simulated: oil, gasoil, gasoline, crude oil, and water. To estimate the gas percentage of a homogeneous two-phase fluid with a distinct type of liquid, data obtained from COMSOL Multiphysics were used as input to train a multilayer perceptron network (MLP). The proposed neural network was modeled in MATLAB software. Using the new and accurate metering system, the proposed MLP model could predict the void fraction with a mean absolute error (MAE) of 4.919.

Human-computer interaction activities as a basis in the development of innovations in process: the case of the colombian exporter Smes

Chang muñoz, eduardo | 2022-10-22

The incorporation of best technological practices or components guides the development of processes and promotes transformations with new approaches in organizational structures. In this regard, it is necessary to increase productivity and competitiveness levels of SMEs. However, having greater knowledge about the type of activities to be implemented for the development of innovations in process is one of the main difficulties usually hindering the growth potential of Small and Medium-sized Enterprises (SMEs). Among the key factors leading to innovation, we find the Human-Computer Interaction (HCI) activities entailing cooperation and the pursuit of R&D activities based on that increase productivity and competitiveness. Nevertheless, several young or small firms do not have those capabilities, and it is paramount for them to know which type of HCI activities they must undertake to allocate their innovation resources adequately to obtain outstanding results. For this purpose, this paper aims to determine the effect of diverse HCI innovation activities on the deployment of innovations within exporter SMEs’ processes. First, we carried out a survey for collecting data on different innovation variables encompassing both activities and processes of 56 exporter SMEs. The data analyzed in this study derive from a structured questionnaire with 21 questions, out of which 16 measured orientations to process innovation, production and distribution methods, techniques, teams and technologies for production whin improve quality; and 5 questions measure the type of innovation activities, such as R&D, links to information sources, cooperation on innovation, scientific, technological, organizational and financial actions. The main economic sectors of these firms are chemical products, fertilizers and pesticides, pharmaceutical and medications, plastic and its manufactures, iron, steel and its manufactures, minerals, oils, vegetal and animals. The model proposed in this study through correlation tests and factorial analyses will allow companies in these economic sectors to know which are the different HCI innovation activities that should be pursued and allow them to devise strategies focusing their efforts and resources in innovative processes. Then, correlation tests and factor analyses were undertaken to identify the main HCI drivers of process innovations in these companies. The results revealed the association between the ease of the technological component through the development of scientific and technological activities with: the number of new or significantly improved processes, techniques, equipment and computer programs to optimize production (p-value = 0.005 χ2 = 12.67); with the implementation of a significant and improved distribution method (p-value = 0,001 χ2 = 15,59) and the implementation of a new production method (p-value = 0,030 χ2 = 7,014). Likewise, it is evinced a significant positive association between the investment on Research, Development and Innovation (RDI) and the number of significantly improved product distribution methods (p-value = 0.019 χ2 = 9.9). These results make it possible to identify the main drivers and the main HCI activities that have an effect on the deployment of process innovations that will benefit the activities of these companies in the long term and boost economic growth. This study serves as a guideline for countries where the required levels of productivity and competitiveness have not been achieved due to the low level of investment in innovation activities and technologies.

El impacto de la cultura organizacional sobre la estrategia competitiva y su influencia en el desempeño exportador de las pymes de barranquilla, Colombia

Sáenz Castro, Diego | 2016

The goal of this research is to determine the influence of organizational culture on business competitive strategy and its impact on the export performance of SMEs in Barranquilla, Colombia. The study took place from August to November, 2015, and it consisted on a telephone survey applied to a sample of 136 companies, from a population of 165 companies in the area, and a response rate of 50 companies. The theoretical approaches used were the proposed by Cameron and Quinn (2006), related to the cultural factors, and by Porter (1990) and Miles & Snow (1978) for the strategic factors. The results showed that culture has no influence on the strategy, and that the most common strategic orientation used by the companies surveyed is the analyzer type. Regarding the impact of the strategy on export performance, we determined that it does not exist. Regression calculations were made to test the hypotheses, and they were rejected. SMEs surveyed do not have a good export performance according to the Export Performance Index (IDE). All these data were analyzed using the SPSS software.

Necessity of a fintech global regulation

Maldonado Narváez, Marlon Iván | 2020-11-19

This article analyzes the need for international regulation for Fintech businesses. First, a brief analysis is made of the importance of the topic and the risks of the lack of good regulation. Subsequently, different cases of regulation are analyzed at the level of the traditional financial sector, as well as of some States that are considered decisive for the Fintech business, including Colombia, which has shown a good development of such ventures at the regional level. To achieve the task that we set ourselves, the deductive method was used, starting from the generality of the available information, and subsequently to an analysis of specific cases. Regarding the case study, it was a comparative study to offer a broader view of what should be the best applicable regulation. After this analysis, it was concluded that currently no state model would serve as an international model law and that what is required is a dialogue between States and businessmen to be able to approach the issue from different perspectives, in such a way that ensure economic growth and protection of both the economy and consumers internationally.

Responsabilidad fiscal de los interventores. análisis del dolo y la culpa grave

Gil Cadavid, Luis Carlos | 2020-11-25

Se trata en esta oportunidad de una respuesta a un proyecto investigativo que reflexiona acerca de la prueba del dolo y culpa grave de los interventores contractuales en procesos de responsabilidad fiscal, a partir de la revisión analítica de decisiones emanadas de la Contraloría General de la República –Gerencia Bolívar–, en el período de gerencia 2012-2018. Su objetivo general fue analizar la forma como se ha aplicado a los interventores contractuales, el sistema probatorio subjetivo, en los procesos de responsabilidad fiscal adelantados por esta institución. Para tales fines se desarrolló una investigación jurídica, de enfoque cualitativo y tipo documental, haciendo uso del método hermenéutico. En consonancia con ello, la técnica predominante fue el análisis documental y la triangulación hermenéutica de los resultados. Se presenta así una exposición de casos legales, que constituyen una muestra de procesos de esta entidad que habiendo iniciado bajo la Ley 1474 de 2011, fueron fallados antes de culminar el segundo semestre de 2018, en todos ellos se vinculó al interventor como presunto responsable fiscal.

Civil mechanism preventing and resolving a conflict of interest in the russian private law

Alexandrovich Svirin, Yury | 2021-01-28

The article studies the legal mechanism preventing and resolving a conflict of interest in civil law. The Russian public law pays much attention to the prevention of competitive interests but there are still no studies on a conflict of interest in private law. The authors have written this article to consider the relevant legal studies and draw their conclusions. Methods: The authors used the methods of comparative and systemic analysis, synthesis and scientific research to examine such a legal concept as a "conflict of interest in private law". The study aims at analyzing the category of competitive interests in relation to private law, determining its prerequisites, reasons and possible solutions. The authors have concluded that a conflict of interest often causes corporate conflicts among parties involved in corporate relations. Moreover, this type of conflicts arises due to the realization of individual property interests and the possibility of one person to influence the other, for example, a conflict between majority and minority shareholders.

Specifics of developing the institution of public service: international experience and its application in Russia

Georgievich Gurinovich, Alexander | 2021-02-13

This article studies the specific development of public service and the possible application of foreign experience in Russia and other countries. The article aims at conducting a comparative analysis of development patterns typical of the institution of public service in the world and determining their general and distinctive features that should be considered when identifying the objectives of reforming the institution of public service in Russia. Results. The article considers development patterns typical of the institution of public service in foreign countries. The main stages of reforming public service have been examined and analyzed, as well as general and distinctive features of this process have been determined. Conclusions. While defining the main objectives of reforming the Russian institution of public service, it is necessary to consider the positive experience of foreign countries. In particular, attention should be paid to the changes at each stage of reforming, namely: the legal support of public service, the organizational structure of public service, personnel policy, the provision of public services to citizens by state employees, and the development of information society. The prospects for further research are to study the specific development of the institution of public service in developed economies. An in-depth comparative analysis of improving such an institution will enable to use the best foreign achievements in reforming the Russian institution of public service.

La intimidad como derecho humano y la solidaridad como valor constitucional en la era del Covid-19

Mendoza de la Espriella, Felix Ramon | 2021-02-13

El objetivo de este artículo de investigación es abordar desde una perspectiva analítica los alcances del derecho humano a la intimidad, y la afectación al valor de la solidaridad. A partir de medidas estatales con ocasión a la emergencia del COVID-19, como fenómeno de salud pública con implicaciones jurídicas, haciendo especial relación al sistema juridico colombiano. Para este cometido trabajaremos dos tópicos fundamentales: (i) El derecho a la intimidad en Colombia: garantias bajo los márgenes conceptuales de la corte constitucional. (ii) El valor de la solidaridad a examen: constitucionalidad del decreto 568 de 15 de abril del 2020. En este orden como conclusiones preliminares, evidenciamos que la constitucionalidad de la intimidad y la solidaridad, pueden ser puestas en peligro a partir de las lesiones a las garantias primarias como normas axiológicas, que se encuentran bajo la tutela y titularidad de protección del poder ejecutivo central, frente a la declaratoria del Estado de emergencia económica, social y ecológica, que consagra el artículo 215 de nuestra Ley Fundamental.

Performance of biodiesel production by means of Ultrasonic Transesterification

Florez-Marulanda, Juan-Fernando | 2021

Introduction— In recent years, the use of renewable energies and eco-friendly fuels has increased, among which one of the best performance is biodiesel; the paper shows an upgrade in the efficiency and effectiveness laboratory level’s biodiesel obtaining. Objective— Evaluating the production of biodiesel employing ultrasound is presented, leading to improve the response time and efficiency of the reaction, concerning the conventional method using only temperature. Methodology— In the transesterification process, castor oil, methanol, and potassium hydroxide are used, obtaining biodiesel and glycerin. A factorial design with two levels for transit time, mixing temperature, and ultrasound intensity were applied in an instrumented scale reactor to control these variables. Results— In the tests, values close to the reference stoichiometric value of the reaction were obtained. The statistic indicates a normal behavior of data, and identifies it as a factor of incidence in the efficiency of the reaction to the intensity of the ultrasound, concerning the response time of the reaction, the mixing temperature and the intensity of ultrasound. Conclusions— The efficiency of the reaction concerning the studied factors, it only depends on the ultrasound obtaining up to 95.7% of the stoichiometric value; and the response time of the reaction depends on the temperature and ultrasound, obtaining times of formation of product four times faster.