Now showing items 181-200 of 1587

Attitudes towards physics. A study with high school students from the Colombian context

Hernánez-Suarez, C A; Gamboa-Suárez, A A; Suarez, O J (2021-09-03)

Science education should promote the development of competent students in science and develop their interest in science; however, although the role and relevance of science within society is evident; the interest towards ...
Study of the Kinematics and Dynamics of the Ring Pack of a Diesel Engine by Means of the Construction of CFD Model in Conjunction with Mathematical Models

Orozco Lozano, Wilman; Fonseca-Vigoya, Marlen Del Socorro; Pabón-León, Jhon (2021-11-28)

The present research aims to analyze the kinematic and dynamic behavior of the piston ring package. The development of the research was carried out through the development of numerical simulation by means of CFD. The ...
Soil Organic Carbon Dynamics in Two Rice Cultivation Systems Compared to an Agroforestry Cultivation System

Valenzuela-Balcázar, Ibonne Geaneth; Visconti-Moreno, Efraín Francisco; Faz, Ángel; Acosta, José A. (2021-12-23)

After changes in tillage on croplands, it is necessary to assess the effects on soil organic carbon (SOC) dynamics in order to identify if soil is a sink or emitter of carbon to the atmosphere. This study was conducted in ...
SYNERGISTIC CORROSION-WEAR EFFECT IN AUSTENITIC POWDER METALLURGICAL STEEL WITH DIFFERENT TITANIUM ADDITIONS

Aperador, w; Bautista-Ruiz, J; Caicedo, J. (2022-01-01)

To ascertain the influence of titanium percentage in 316L austenitic steel, titanium percentages varied from 0.5 to 2% aggregated to 316L steel. The powder metallurgy method was used. The powdered material was pressed at ...
A Simulation Analysis of a Microalgal-Production Plant for the Transformation of Inland-Fisheries Wastewater in Sustainable Feed

García-Martínez, Janet B; Contreras-Ropero, Jefferson E; Urbina-Suarez, Néstor A.; López-Barrera, Germán L.; Barajas-Solano, Andrés F; Kafarov, Viatcheslav; Barajas-Ferreira, Crisóstomo; Ibarra-Mojica, Diana M.; Zuorro, Antonio (2022-01-16)

The present research evaluates the simulation of a system for transforming inland-fisheries wastewater into sustainable fish feed using Designer® software. The data required were obtained from the experimental cultivation ...
Prospects for using wastewater from a farm for algae cultivation: The case of Eastern Colombia

Urbina-Suarez, Nestor Andres; Barajas-Solano, Andres Fernando; Garcia-Martinez, Janet Bibiana; Lopez-Barrera, German Luciano; González-Delgado, Angel Dario (2021-05-24)

: In recent years, the technical and economic feasibility of using microalgae and cyanobacteria has been explored for the removal and exploitation of domestic, agricultural and industrial residual effluents with high C, ...
Public space as a right: Accessibility for people with disabilities in the in the town centre of Cúcuta

Rangel Goyeneche, Diana Carolina; Corenel Ruiz, Luz Karime (2021-10-23)

Todo ciudadano sin importar su condición económica, social o física deberá gozar de las mismas condiciones, oportunidades de uso y disfrute del espacio público, libre de toda restricción o discrimina-ción que ...
Psychological well-being in nurses performing renal replacement therapy in times of COVID-19 pandemic

Martínez-Rojas, Sandra Milena; Ruiz-Roa, Silvia Liliana (2022-03-30)

Introducción: La pandemia por COVID-19 ha generado dete-rioro de la salud mental en los profesionales del sector salud, siendo desconocida su situación en las enfermeras al cuidado de pacientes con enfermedad renal crónica. ...
Education, innovation, entrepreneurship, growth and development in Latin America

Rincón Soto, Idana Beroska; Rengifo Lozano, Raúl Alberto; Hernández Suárez, César; Prada Núñez, Raúl (2022-07-01)

The importance of education to promote the processes inherent to innovation and entrepreneurship is currently of vital importance in professional training, which in turn links the impact it has on macroeconomic variables ...
Analysis of the influence of textured surfaces and lubrication conditions on the tribological performance between the compression ring and cylinder liner

Pardo García, Carlos Eduardo; Rojas Suárez, Jhan Piero; Orjuela Abril, Martha Sofia (LubricantsSuiza, 2021-05-06)

The objective of the present investigation is to analyze the tribological performance between the union of the cylinder liner and the compression ring under the influence of surface texturing and different lubrication ...
Document details - A numerical model for the analysis of the bearings of a diesel engine subjected to conditions of wear and misalignment

Pardo García, Carlos Eduardo; Rojas Suárez, Jhan Piero; Orjuela Abril, Martha Sofia (LubricantsSuiza, 2021-04-09)

In the present work, a numerical model is developed to investigate the influence of wear and misalignment on the bearings of a stationary diesel engine. The model implemented considers the effects of surface wear on the ...
Impact of plasticizers on the physical and structural properties of concrete used in constructions

GARZÓN AGUDELO, PEDRO; palacios alvarado, wlamyr; Medina Delgado, Byron (Reino Unido, 2021-06-04)

Concrete has an important presence in the construction of buildings and civil works, so its application requires taking into account the standards, technical specifications and technologies that guarantee the structural ...
Application of neural and bayesian networks in diesel engines under the flaw detection method

Prada Botia, Gaudy Carolina; PABON LEON, JHON ANTUNY; Orjuela Abril, Martha Sofia (Reino Unido, 2021-05-22)

The identification of premature faults in Internal Combustion Engines has become determinant to guarantee suitable operation. Therefore, this study focuses on the implementation of fault diagnostic methodology by using ...
GIT-SEED: Strategy for collaborative work in software development courses

Adarme Jaimes, Marco Antonio; Rodriguez Tengo, Judith del Pilar; Gallardo Perez, Oscar Alberto (2022-07-18)

El desarrollo de software es considerado una actividad compleja debido a que intervienen un conjunto de personas especializadas en lenguajes y herramientas de programación que realizan tareas bien definidas dentro de ...
Relevance of the use of measurement units and orders of magnitude in the training of civil engineers

Márquez Peñaranda, J F; Cáceres Rubio, J R; Pineda Rodríguez, J R (Reino Unido, 2021-05-22)

Worldwide, a typical civil engineering program focuses in formal, natural, and applied sciences within an environment of ethical and social responsibility. Mathematics and computer sciences are the main formal sciences. ...
Characterization of clay material and rice husk from northeast Colombia

Sanchez Molina, Jorge; Bautista-Ruiz, Jorge; Sánchez Zúñiga, J. V. (Rasayan Journal of ChemistryIndia, 2021-01)

This research was to study materials from the region to use them industrially applying the circular economy concept. Clay Material and Rice Husk were evaluated in the manufacture of ceramic products. X-ray Diffraction and ...
Study of the benefit of solar energy through the management of photovoltaic systems in Colombia

Orjuela Abril, Martha Sofia ; PABON LEON, JHON ANTUNY; García, José Orlando (International Journal of Energy Economics and PolicyTurquía, 2021)

One of the biggest problems in energy management is the impact on the environment. For this, it is necessary to propose new techniques and strategies which reduce pollution. Examples such as carbon dioxide and other ...
Active learning and knowledge in physics: a reading from classroom work

Prada Nuñez, Raul; C A, Hernández Suarez; Gamboa, A A (Reino Unido, 2021-05-22)

This research article shows the findings of a study that sought to demonstrate the results of a methodological intervention implemented in classes of an eleventh-grade course in the area of Physics, in a public school ...
The rubric as an assessment tool for solving problem situations in the physics and mathematics teaching context

Salazar Torres, J; Rincón Leal, Olga Lucy; Vergel Ortega, Mawency (Reino Unido, 2021-05-22)

Polya propose the didactic problem-solving strategy to strengthen the teaching and learning processes in the mathematic field. Thus, this strategy can be applied in other fields such as physics teaching the article ...
Teaching physics through the implementation of a didactic strategy for the integration of knowledge in secondary school students

Prada Nuñez, Raul; Hernández, C A; Gamboa, A A (Reino Unido, 2021-05-21)

The objective was to evaluate the implementation of the knowledge integration model in high school students studying physics in a public educational institution in the city of San José de Cúcuta, Colombia. A quasi-experimental ...

Envíos recientes

Attitudes towards physics. A study with high school students from the Colombian context
...
Hernánez-Suarez, C A | 2021-09-03

Science education should promote the development of competent students in science and develop their interest in science; however, although the role and relevance of science within society is evident; the interest towards it is not conscious, being the negative attitudes of the students the main problem in the teaching of physics, which translates into a deficient knowledge and lack of scientific vocation. This report aims to diagnose the attitudes of students in high school physics courses. The study was developed through a non-experimental, descriptive research design, obtained from the application of a Likert scale that evaluates attitudes towards physics, adapted and validated to the context of students in an educational institution in Colombia. The results indicate that the attitudes of the students are slightly favorable, which is an empirical precedent to continue with the studies on attitudes towards physic. This should be considered to enhance the learning processes in these students, especially for those who have their first approach to physical concepts and give importance to attitudes when teaching.

LEER
Study of the Kinematics and Dynamics of the Ring Pack of a Diesel Engine by Means of the Construction of CFD Model in Conjunction with Mathematical Models
...
Orozco Lozano, Wilman | 2021-11-28

The present research aims to analyze the kinematic and dynamic behavior of the piston ring package. The development of the research was carried out through the development of numerical simulation by means of CFD. The analysis involves the three piston rings for the development of simulations that are closer to the real conditions of the engine since most of the investigations tend to focus on the study of the compression ring only. The simulation was reinforced by the incorporation of mathematical models, which allow determining the piston kinematics, the lubrication properties as a function of temperature, contact friction, and gas leakage. For the simulation, the CAD of the piston and the connecting rod—crankshaft mechanism was carried out, taking as a reference the geometry of a diesel engine. From the results obtained, it was possible to show that the first ring exhibits considerably greater radial and axial movement compared to the second and third piston rings. Additionally, it was shown that the first and second rings tend to maintain a negative tilt angle throughout the combustion cycle, which facilitates the advancement of the combustion gases over the piston grooves. Therefore, it is necessary to use strategies so that these rings tend to maintain a positive inclination. The analysis of the pressure conditions in the second ring are 150% and 480% higher compared to the conditions present in the third ring. Due to the above, it is necessary to focus efforts on the design of the profile of this ring. The study of energy losses showed that the combination of leakage gases and friction are responsible for a mechanical loss between 6–16%. In general, the development of the proposed methodology is a novel tool for the joint analysis of the kinematic characteristics, pressure conditions, and energy losses. In this way, integrated analysis of changes caused by piston ring designs is possible.

LEER
Soil Organic Carbon Dynamics in Two Rice Cultivation Systems Compared to an Agroforestry Cultivation System
...
Valenzuela-Balcázar, Ibonne Geaneth | 2021-12-23

After changes in tillage on croplands, it is necessary to assess the effects on soil organic carbon (SOC) dynamics in order to identify if soil is a sink or emitter of carbon to the atmosphere. This study was conducted in two plots of rice cultivation, where tillage and water management changes occurred. A third plot of native forest with Cacao trees was used as reference soil (agroforestry). For SOC balance estimation, measurement of organic carbon (OC) inputs was determined from necromass, roots, microbial biomass, and urea applications. CO2 and CH4 emissions were also measured. Results showed that the change in the use of irrigation and tillage in rice cultivation did not cause significant differences in OC inputs to soil or in outputs due to carbon emissions. Further-more, it was found that both irrigation and tillage management systems in rice cultivation com-pared with agroforestry were management systems with a negative difference between OC inputs and outputs due to CO2 emissions associated with intense stimulation of crop root respiration and microbial activity. The comparison of SOC dynamics between the agroforestry system and rice cultivation systems showed that an agroforestry system is a carbon sink with a positive OC dynamic.

LEER
SYNERGISTIC CORROSION-WEAR EFFECT IN AUSTENITIC POWDER METALLURGICAL STEEL WITH DIFFERENT TITANIUM ADDITIONS
...
Aperador, w | 2022-01-01

To ascertain the influence of titanium percentage in 316L austenitic steel, titanium percentages varied from 0.5 to 2% aggregated to 316L steel. The powder metallurgy method was used. The powdered material was pressed at 800 MPa and then sintered at 1300°C. The X-ray diffraction (XRD) technique was used to characterize the identification of the phases after the processed mixtures. Wear and tribowear properties were determined by pin on disc tests. Electrochemical polarization curves were used to study corrosion. According to the results of the samples, the corrosion resistance of titanium increased to a percentage of 1.5% due to the formation of the phases generated by the mixture. However, it was determined that the most appropriate percentage is 2%, due to the synergistic mode specifically for wear and corrosion resistance, the mechanism is the most adequate.

LEER
A Simulation Analysis of a Microalgal-Production Plant for the Transformation of Inland-Fisheries Wastewater in Sustainable Feed
...
García-Martínez, Janet B | 2022-01-16

The present research evaluates the simulation of a system for transforming inland-fisheries wastewater into sustainable fish feed using Designer® software. The data required were obtained from the experimental cultivation of Chlorella sp. in wastewater supplemented with N and P. According to the results, it is possible to produce up to 11,875 kg/year (31.3 kg/d) with a production cost of up to 18 (USD/kg) for dry biomass and 0.19 (USD/bottle) for concentrated biomass. Similarly, it was possible to establish the kinetics of growth of substrate-dependent biomass with a maximum production of 1.25 g/L after 15 days and 98% removal of available N coupled with 20% of P. It is essential to note the final production efficiency may vary depending on uncontrollable variables such as climate and quality of wastewater, among others.

LEER
Prospects for using wastewater from a farm for algae cultivation: The case of Eastern Colombia
...
Urbina-Suarez, Nestor Andres | 2021-05-24

: In recent years, the technical and economic feasibility of using microalgae and cyanobacteria has been explored for the removal and exploitation of domestic, agricultural and industrial residual effluents with high C, N and P compounds content. To contribute to the understanding of the process and its technical viability for microalgae growth, the article discusses monitoring, flow determination, and physicochemical characteristics of two types of effluents generated in an experimental farm located in the east of Colombia, before (R1) and after biological treatment (R2). In general, the results showed the reduction of different parameters, such as total dissolved solids (TDS), hardness, salinity and phosphates after treatment with activated sludge. However, the conductivity value obtained in R1 and R2 showed the presence of a pollutant load. These findings can be attributed to the highest concentration of fats and oils in the water during early hours of the day. Finally, although the concentration of nitrates increased from 46.63 to 225.21 mg∙dm–3 and phosphate decreased slightly from 9.65 to 6.21 mg∙dm–3, no inhibition was generated in the microalgae, as evidenced in the growth of the microalgal biomass in effluents after nitrate and phosphate removal above 80%.

LEER
Public space as a right: Accessibility for people with disabilities in the in the town centre of Cúcuta
...
Rangel Goyeneche, Diana Carolina | 2021-10-23

Todo ciudadano sin importar su condición económica, social o física deberá gozar de las mismas condiciones, oportunidades de uso y disfrute del espacio público, libre de toda restricción o discrimina-ción que tenga el propósito de obstaculizar su inclusión en el paisaje urbano. Por lo tanto, las personas con discapacidad, como actores dentro del mismo, deberán participar activamente en las decisiones que afecten su configuración, ordenamiento y proyección. A partir de la mirada personal de quienes se enfrentan desde su condición el espacio público en la zona céntrica de la ciudad colombiana de Cúcuta. El presente estudio desarrollado en el año 2018, consolida el análisis de percepción en materia de accesibilidad al medio urba-no de los individuos con los tipos de alteración más representativos en la ciudad. Para tal fin, la investigación hizo empleo de una me-todología cualitativa: muestreo avalancha y herramientas como la observación participante y entrevista, que permitieron consolidar una línea base de indicadores del espacio público para la población con limitaciones, como instrumento de medición de la calidad de vi-da y bienestar social en las ciudades y elemento enriquecedor en la formulación de las políticas públicas en materia de espacio público.

LEER
Psychological well-being in nurses performing renal replacement therapy in times of COVID-19 pandemic
...
Martínez-Rojas, Sandra Milena | 2022-03-30

Introducción: La pandemia por COVID-19 ha generado dete-rioro de la salud mental en los profesionales del sector salud, siendo desconocida su situación en las enfermeras al cuidado de pacientes con enfermedad renal crónica. Objetivo: Identificar el bienestar psicológico y sus diferencias de acuerdo a las variables demográficas y profesionales en en-fermeras que realizan hemodiálisis en tiempos de COVID-19. Material y Método: Estudio cuantitativo, descriptivo trans-versal, realizado en 52 enfermeras que realizan terapia de reemplazo renal en unidades de cuidado intensivo y de terapia renal en tiempos de COVID-19. Fueron obtenidas variables de tipo sociodemográfico, académico, laboral y se empleó la escala PGWBI para establecer los niveles de bienestar psicológico. Se utilizó el test de Mann-Whitney y Kruskall-Wallis realizando el post test de Dunn para compa-rar diferencias entre las variables estudiadas. Resultados: La edad promedio fue de 36,56±6,95 años. Los niveles de bienestar psicológico fueron positivos en todas las categorías de la escala, con excepción de la ansiedad y la depresión. De igual forma, se encontró que las variables género, estado civil, estabilidad, antigüedad laboral, remu-neración salarial y formación académica, muestran compor-tamiento diferenciado en las categorías que evalúa el ins-trumento. Conclusiones: Se identificaron altos niveles de bienestar psicológico en enfermeras que prestan cuidados en pacien-tes en terapia de reemplazo renal en tiempos de pandemia por COVID-19, donde factores como el estado civil, forma-ción post gradual y tener estabilidad laboral con mejores ingresos salariales, influencian positivamente las categorías que contribuyeron a los resultados de bienestar psicológico de las enfermeras evaluadas.

LEER
Education, innovation, entrepreneurship, growth and development in Latin America
...
Rincón Soto, Idana Beroska | 2022-07-01

The importance of education to promote the processes inherent to innovation and entrepreneurship is currently of vital importance in professional training, which in turn links the impact it has on macroeconomic variables such as economic growth and development of an economy. In this sense, the general objective of the research is to explain the influence of education on variables such as innovation, entrepreneurship and its impact on growth and development, in this particular, in Latin American countries. From the methodological point of view, a documentary review is made regarding future projections within the framework of these variables, and a statistical analysis of cases such as America, Europe and Asia, in order to integrate the different experiences and models, taking as reference the results that in praxis are currently consonant with each one in particular. Finally, the importance of framing in education the congruence and pragmatic coherence of the objectives of public policies in terms of innovation, research, science and technology is concluded, which in turn promotes the multiplier effect in synergy with the private business sector, promoting between both variables such as growth, poverty and development.

LEER
Analysis of the influence of textured surfaces and lubrication conditions on the tribological performance between the compression ring and cylinder liner
...
Pardo García, Carlos Eduardo | 2021-05-06

The objective of the present investigation is to analyze the tribological performance between the union of the cylinder liner and the compression ring under the influence of surface texturing and different lubrication boundary conditions. The analysis is carried out by developing a numerical model, which involves hydrodynamic pressure, lubrication film thickness, textured surface, dynamic forces, and lubrication boundary conditions (starved lubrication and fully flooded lubrication). MATLAB® software (The MathWorks Inc., Natick, MA, USA) is used to solve the equations developed. The results show that the application of a textured surface on the cylinder liner allows obtaining a reduction of 20% and 5% in the asperity contact force and in the total friction force. Additionally, the textured surface allows for a 4% increase in MOFT. In this way, it is possible to reduce the power loss. The implementation of a boundary condition of fully flooded lubrication produces an overestimation in the total friction force due to the greater prominence of the lubrication film. Implementing a textured surface in the ring profile is an alternative way to reduce power loss. The results show that this alternative allows an 8% reduction in power loss.

LEER
Document details - A numerical model for the analysis of the bearings of a diesel engine subjected to conditions of wear and misalignment
...
Pardo García, Carlos Eduardo | 2021-04-09

In the present work, a numerical model is developed to investigate the influence of wear and misalignment on the bearings of a stationary diesel engine. The model implemented considers the effects of surface wear on the bearing, cavitation effects, and surface roughness. For the numerical analysis, changes in the surface roughness of σ = 0.75 µm, σ = 1 µm, and σ = 1.25 µm are defined, and changes in the bearing load of 50%, 75%, and 100%. The results demonstrated that increasing the surface roughness intensifies the bearing wear, which represents 18% and 140% of the bearing clearance for the roughness of σ = 1 µm and σ = 1.25 µm, respectively. Additionally, the surface roughness causes a considerable increase in the bearing wear rate. The results described a maximum wear rate of 20 µm/s. In general, increasing the bearing load by 25% doubles the hydrodynamic pressure conditions increases friction force by 33%, and reduces lubrication film thickness by 12%. The analysis of the angle of deflection, φx and φy, shows that the moment and the degree of misalignment tend to increase significantly with the increase in the magnitude of the angle φy. Negative angles of deflection, φx, produce a greater increase in the degree of misalignment and the moment. This implies a greater chance of contact with the bearing surface. In conclusion, the proposed methodology serves as a reliable tool to simultaneously evaluate key parameters on the tribological behavior of bearings that further extend their endurance and minimize wear damage.

LEER
Impact of plasticizers on the physical and structural properties of concrete used in constructions
...
GARZÓN AGUDELO, PEDRO | 2021-06-04

Concrete has an important presence in the construction of buildings and civil works, so its application requires taking into account the standards, technical specifications and technologies that guarantee the structural stability expected by the manufacturers of materials and builders, and that is why the use of plasticizers arises as an adjuvant to the physical and mechanical properties of concrete. The objective of this article was to highlight the importance of plasticizers in the main properties of concrete used in construction and the ideal conditions for their use; based on a qualitative and quantitative approach methodology, scientifically validated sources of information related to the subject of the study were analyzed. It was possible to demonstrate significantly favorable results with the application of plasticizers as water reducers that increase mechanical strength, provided that they are used in an adequate proportion of these additives to improve the physical properties of concrete.

LEER
Application of neural and bayesian networks in diesel engines under the flaw detection method
...
Prada Botia, Gaudy Carolina | 2021-05-22

The identification of premature faults in Internal Combustion Engines has become determinant to guarantee suitable operation. Therefore, this study focuses on the implementation of fault diagnostic methodology by using advanced algorithms such as Back Propagation neural networks and Bayesian networks. Results indicated that the proposed methodology serves as a robust tool to identify different fault conditions in a wide operational spectrum with an reliability of nearly 73%. Moreover, the Backpropagation network diagnostic methodology presented an reliability of 18%, which is 3% higher than Bayesian networks. Overall, the implemented methodology counterbalanced interference conditions and noise signals while providing versatility to operate for different types of engines. In conclusion, this study can be extrapolated to different fields of physics to assist in identifying flaws in experimental test benches.

LEER
GIT-SEED: Strategy for collaborative work in software development courses
...
Adarme Jaimes, Marco Antonio | 2022-07-18

El desarrollo de software es considerado una actividad compleja debido a que intervienen un conjunto de personas especializadas en lenguajes y herramientas de programación que realizan tareas bien definidas dentro de la implementación del software. En este contexto de trabajo, se hace necesario que el estudiante en su inicio de formación como desarrollador de software, tome habilidades en buenas prácticas de desarrollo, una de los cuales comprende la utilización de sistemas de controles de versiones que permiten el registro y control de cambios de proyectos de software en repositorios específicos de código de programación donde interactúan varios usuarios. El propósito de este trabajo es presentar una estrategia de aprendizaje denominada GIT-SEED basada en casos donde el estudiante trabaje de forma colaborativa con el uso de un sistema de control de versiones bajo la plataforma GitLab, desde esta perspectiva se ofrece un mecanismo de apoyo para las habilidades de trabajo en equipo, análisis y pruebas de código de programación, despliegue de aplicaciones en entornos reales de trabajo y manejo de procesos de desarrollo de software ágiles. Los escenarios de prueba de la estrategia fueron aplicados a los estudiantes de estructura de datos y programación web del Programa de Ingeniería de Sistemas de la Universidad Francisco de Paula Santander, los resultados demuestran la gran afinidad y apropiación que tienen los estudiantes en el uso de estas herramientas y la facilidad de integración de sus aplicaciones con los componentes creados en su equipo de trabajo.

LEER
Relevance of the use of measurement units and orders of magnitude in the training of civil engineers
...
Márquez Peñaranda, J F | 2021-05-22

Worldwide, a typical civil engineering program focuses in formal, natural, and applied sciences within an environment of ethical and social responsibility. Mathematics and computer sciences are the main formal sciences. The most widely used natural sciences are physics, earth science, and chemistry. On the other hand, a student who begins the professional cycle of the program must develop skills in applied science to solve practical problems. Complex processes and concepts requiring skills related to mathematics and physics must be developed. Such processes and concepts demand an impeccable handling of operations which involve diverse precision degrees, measurement units and a high variety of basic and derived quantities. This work describes the identification and classification of the main errors made by students when solving written exams applied in a natural environment of structural design courses. Data were collected during four years at a university in Colombia. Report of errors was grouped into five categories named modelling, quantities, regulation, signs, and others. Collected errors were evaluated qualitatively and quantitatively. In addition, each error was assigned to a risk level (high, intermediate, low) according to its potentiality to generate catastrophic errors in professional practice. The quality and number of observed errors seem to be correlated with the time of year in which they occur. On the other hand, the high-risk errors resulted to outweigh the two lower risk levels. This finding is worrying and serves as the basis for making an urgent call to review the way of teaching and its relationship with practical results. In synthesis, this study presents a novel manner to study the formation errors in engineering civil programs. In the near future, it is expected to use the results of this research to propose a procedure for the design and feedback of teaching strategies consistent with the evaluation objectives of each course.

LEER
Characterization of clay material and rice husk from northeast Colombia
...
Sanchez Molina, Jorge | 2021-01

This research was to study materials from the region to use them industrially applying the circular economy concept. Clay Material and Rice Husk were evaluated in the manufacture of ceramic products. X-ray Diffraction and X-ray Fluorescence techniques were used to determine the raw materials' chemical and mineralogical composition. Thermal analysis techniques (TG and DTG) were used to complement the study. The XRD results showed an abundance of quartz. The results of the thermal analysis establish significant losses due to calcination. The thermal conductivity was also measured in ceramic specimens made from two types of pastes, one with 100% Clay Material and the other with a 5% substitution for Rice Husk. The results showed a decrease in thermal conductivity in the test tubes with the addition of Rice Husk. Consequently, the Rice Husk as a substitute for the Clay Material allows for ceramic production with thermal efficiency.

LEER
Study of the benefit of solar energy through the management of photovoltaic systems in Colombia
...
Orjuela Abril, Martha Sofia | 2021

One of the biggest problems in energy management is the impact on the environment. For this, it is necessary to propose new techniques and strategies which reduce pollution. Examples such as carbon dioxide and other greenhouse gas emissions promote an increase in the carbon footprint. This carries the search for resources from renewable sources as sunlight, wind, rain, waves, etc. From these sources, solar energy could be used in Colombia, especially the Atlantic Coast, due to high solar radiation in this region. This study is going to collect information about the advantages and disadvantages of using photovoltaic systems (PV systems) for solar energy management with a good cost-efficiency ratio. On the other hand, the development of solar energy will be studied and compared with other energy sources. In Colombia, there is a set of energy and regulatory policies around small self-generators with renewable energy sources, which can be natural or legal persons, that is, self-generators could be civilians, merchants, or small industries. Finally, it will be discussed about the energy plans as a proposal for improved energy management in the future.

LEER
Active learning and knowledge in physics: a reading from classroom work
...
Prada Nuñez, Raul | 2021-05-22

This research article shows the findings of a study that sought to demonstrate the results of a methodological intervention implemented in classes of an eleventh-grade course in the area of Physics, in a public school in the city of San José de Cúcuta, Colombia. The intervention consisted of applying some active learning strategies accompanied by methodological tools such as collaborative work in order to measure the impact of the intervention on the level of disciplinary knowledge of students with a pre-test and post-test. The results show a significant increase with a value of 0.49 at the end of the intervention, which suggests that the subjects participating in the study improved their level of conceptual appropriation in physics after the application of active learning strategies.

LEER
The rubric as an assessment tool for solving problem situations in the physics and mathematics teaching context
...
Salazar Torres, J | 2021-05-22

Polya propose the didactic problem-solving strategy to strengthen the teaching and learning processes in the mathematic field. Thus, this strategy can be applied in other fields such as physics teaching the article proposes an evaluation strategy based on the design of a rubric to assess the processes associated with solving mathematical problems, as a classroom research work based on Research, Pedagogical Action. As one of the results, an analytical rubric composed of criteria and indicators associated with the steps of Polya problem solving is proposed, as well as a reflection associated with the teaching of problem solving in the engineering area.

LEER
Teaching physics through the implementation of a didactic strategy for the integration of knowledge in secondary school students
...
Prada Nuñez, Raul | 2021-05-21

The objective was to evaluate the implementation of the knowledge integration model in high school students studying physics in a public educational institution in the city of San José de Cúcuta, Colombia. A quasi-experimental model was applied. An intervention was implemented as a didactic strategy for the integration of knowledge based on the Pragmatic Pedagogical Principles, its operative criteria, and activities. Conceptual progress is reported by means of Hake's normalized factor or gain, which was modified to the rating scales, and the results of partial exams are considered, implementing a continuous and formative evaluation system. The results were compared between the experimental and control groups. It was found that the experimental group showed better academic achievement and performance than the control group. This suggests that the results generated a continuous learning progress thanks to the application of the operative judgments of the corresponding principles.

LEER