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B. Investigación

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The Covid-19 pandemic in low- and middle-income countries, who carries the burden? Review of mass media and publications from six countries

Chackalackal, Dhia Joseph | 2021-03-04

During the Covid-19 pandemic, rich countries employed lockdown and physical distancing policies for transmission control. However, the question still remains whether these measures are also suitable in countries with a fragile economy, which rests mainly on the informal sector. The impacts of lockdown measures in disadvantaged population strata in six low- and middleincome countries (LMICs) were reviewed using i) 93 media reports and ii) 17 published scientific papers. This review showed that those who suffered the most from the lockdown were migrants, workers in the large informal sector, small businesses, slum dwellers, women and elderly, revealing the social, cultural and economic inequalities of societies. Financial and food support for the poor was inadequate and sometimes mismanaged. In the better organized societies, the resilience was stronger (South Korea, Kerala/India) but here also the poor had to suffer the most. It is strongly recommended that outbreak response strategies should particularly focus on the poor and vulnerable population.

Detection of water leaks with Dowsing technique and Reynold's transport theorem

García Guarín, J | 2021-05-22

Zahorí techniques are traditionally used to detect water currents in land for subsequent extraction. On the other hand, water leaks represent economic losses in factories and residences. It is enough to survey a city and determine the exaggerated number of residential leaks. Once the leak appears, a corrective action must be taken, this action is founded in itself and in the problems derived from this failure; and it is that knowing the exact location of a leak is risky if strictly collateral damage appears in the property. This research proposes to complement two different techniques, the first detects the presence of water based on the Dowsing search, and the second uses the Reynolds Transport Theorem to detect the leak relying on numerical methods and computational simulation. The Dowsing search proved to be reliable to detect the presence of water, the Reynolds Transport Theorem, yields the location of the leak with an average relative error of 10.6727% and the computational simulation corroborates Darcy's Law. Therefore, the method proposed in this investigation is sufficient for the corrective management of leaks.

Physical parameters for the estimation of the return coefficient in the sewer of the La Chivera watershed

calixto, nelson javier | 2021-06-10

Estimating the amount of flow carried by the sanitary sewer system in a locality is essential for the design of new facilities. Having a record of the flow rates allows the adequate hydraulic design of a drainage system. The objective of this work is to determine the physical parameters for the estimation of the return coefficient that allows estimating the flow rates for the sanitary sewer of the La Chivera watershed, San José de Cúcuta, Colombia. In this sense, dry weather monitoring of the wastewater in the study area was carried out. The data collected in the field were used to construct the hourly flow variation curve or inflow hydrograph in the drainage system. The average hourly flow parameters were estimated with a value of 205.7 m3/h, a value recorded at the 11th hour of the day. Similarly, the average daily flow was determined with a value of 180.3 m3/h, while the maximum peak factor was 1.14. Finally, through the physical parameters of the sanitary sewer, the return coefficient was determined, which is 0.72, a value that represents the conditions of the study area.

Development of an electro-pneumatic system for the practical training of pneumatic processes in the university environment

Rojas Suárez, Jhan Piero | 2021-06-11

This article describes the implementation of an electro-pneumatic test bench, which allows the availability of a physical environment to promote learning. The aim of the paper is to create a tool that enables practical training and research of pneumatic processes for university students in the field of engineering. The control and automation system of the test bench is made up of wired logic panels, timers, and programmable logic controllers, which are integrated into a control board configured at 24 V (direct current) to guarantee safety. Additionally, ergonomic principles were considered for the construction of the electro-pneumatic bench, thus favoring the accessibility and safety of the users. Based on national and international regulations, working pressure of 9 bar and an approximate pressure drop of 0.07 bar were defined. The construction of the test bench is considered an educational strategy to facilitate and accelerate the learning process of the students. Additionally, the development of the electro-pneumatic bench allowed the dynamic characterization of double-acting actuators by integrating experimental data and numerical models. This allowed the detailed analysis of the displacement, velocity, and acceleration variables in this type of actuator, which contributes to the physical study of pneumatic systems.

Physics in the structure and form of the architectural project. Museum of Contemporary Art Niterói, Brazil

CORONEL, LUZ KARIME | 2021-06-10

This article analyzed the formal, functional, and structural aspects of the Museum of Contemporary Art Niterói in Brazil, by identifying the criteria associated with architecture and physics; this is to establish the importance of the analysis of the architectural project to obtain the basic skills of the architect. A mixed methodological framework was used, the quantitative phase was developed from a questionnaire under a non-probabilistic sample allowed to recognize the formal, structural, and functional aspects of the work under study, the qualitative phase used an interview that established the value represented by the recognition of the application of physics in architecture. As a relevant finding, it is highlighted a basic understanding of the physical elements applied to architecture, specifically in the case of Museum of Contemporary Art Niterói, Brazil, and that they recognize the importance of the analysis of architectural works as a pedagogical tool that favors obtaining the basic skills of the architect.

Teaching the concept of the uniform plane wave from mathematical modeling

Medina Delgado, Byron | 2021-06-10

The discovery of electromagnetic waves enabled us to understand electricity, magnetism, and optics under the same field; therefore, it is important for electronic and related engineers to understand the concept of the uniform plane wave, which represents the simplest case of an electromagnetic wave propagating through a medium. However, this concept is taught with a theoretical approach, shows a need for a methodological change towards experimentation to mitigate poor learning in students causing a high failure rate in electromagnetism courses. In this context, this work presents a methodological alternative for teaching the concept of the uniform plane wave, combining the CUVIMA model with the didactics of mathematical modelling, to link experimentation and provide cognitive support to the conceptualization of the physical phenomenon. For it, a single-group design is implemented, with pre-test and post-test, to know about previous ideas and identify the conceptual change achieved for the students. When applying the Student's t-test at a significance level of 5%, a significant difference is evident between the means of the study groups. It is concluded that there is a favorable and representative conceptual change in the students, with respect to the understanding of the physical phenomenon represented by the concept of the uniform plane wave.

Effect of concentration areas in sensitive analysis of a hybrid solar Brayton cycle

Moreno Gamboa, Faustino | 2021-06-11

A simple hybrid solar thermal Brayton cycle plant thermodynamic model is evaluated in northern Colombia, where the maximum solar radiation values in the country are found. The model considers the different irreversibilities of the cycle and is coupled to a model for estimating direct solar radiation as a complementary energy source for the plant. The stability in the operation of the cycle is determined by a combustion chamber that complements the energy supply. As a result of the analysis, this work presents the sensitivity analysis of different operating parameters of the plant as a function of the areas of the concentration ratio of the solar system when the contribution of this system is maximum. It is observed that fuel consumption is reduced by 34.7% when increasing the concentration ratio between 200 and 700.

Impact of colchicine on leaf morphology and stomatics of Kalanchoe tubiflora (Harv.) Raym.- Hamet (Crassulaceae)

SALAZAR MERCADO, SEIR ANTONIO | 2021-09-24

The demand of medicinal plants for consumption is greatly increasing worldwide. The conventional breeding programs are generally dependent on the environment prone to biotic and abiotic stresses. These added to the low content of secondary metabolites at harvest, bring the need for artificial development of polyploid individuals as an alternative to increase productivity. Consequently, the present study evaluated the effect of different colchicine concentrations and exposure time, on Kalanchoe tubiflora leaf morphology and stomata. Initially, K. tubiflora seedlings were harvested and submitted to colchicine concentrations of 0, 0.025, 0.05 and 0.1 % and at two exposure times (24 and 48 hours). Subsequently, morphological measurements such as plant height, leaf width, leaves number, leaf length, leaf thickness and leaf volume every 15 days were made for 16 weeks after planting. Then, the stomata were characterized, taking into account the width, length, stomatal index and the number of chloroplasts per stoma. A significant increase in leaf morphology was found in colchicine treatments of 0.025 % at 48 h and 0.1 % at 24 h. A significant increase in stomatal morphology with the treatment of 0.025 % at 24 h was also recorded. This shows that the correct application of colchicine in term of quantity and time could produce greater growth in a short period and increase the biomass of K. tubiflora medicinal plant

Underlying variables in the understanding of movement in engineering students

Gamboa Suárez, Audin Aloiso | 2021-08-26

This article describes the understanding of motion by active students taking Newtonian physics for engineering, supported by active learning, during the pandemic due to COVID-19; in addition, an unsupervised predictive model of learning achievement was constructed from variables identified using the principal component analysis technique on the responses. the instrument used is the modified test of understanding graphs-kinematics comprehension. students from two universities in Bogotá, Colombia participated. The results show a lower level of accuracy in students in remote face-to-face mode, compared to the reference group of physical presence; by way of reflection, the forced educational experiment implies resizing the teaching activity in the teaching and learning of movement.

Didactic Engineering as a research method in physics teaching

Avendaño Castro, William Rodrigo | 2021-08-26

Several mathematical concepts have application in physics; this paper reports the results of a pedagogical investigation based on the methodology known as didactic engineering, which has been proposed with the aim of improving the skills exhibited by a group of eleventh grade students from a private institution in the interpretation of kinematic graphs. The concept of the slope of the straight line and how this mathematical concept can represent velocity or acceleration according to the variables considered in the kinematics graph provided was enhanced in the pedagogical intervention. This methodology offers a process of internal validation, after comparing the results obtained in a knowledge test at two different points in time (pre-test and post-test). The results allowed us to identify improvements in all students in terms of basic kinematics graph interpretation skills, and a group of students stood out by advancing in more complex reasoning and interpretation processes. These results contribute to the improvement of the pedagogical practices of Physics teachers at secondary and middle school levels, making them more competent when they enter higher education.

Analysis of heat fluxes in ceramic block type building pieces

Sanchez Molina, Jorge | 2021-09-02

In Norte de Santander, Colombia, there is a ceramic cluster made up of 59 companies dedicated to the production of construction materials derived from clay, a vernacular material with a wide extraction potential in the region. Fired clay products in different hollow block presentations represent 15% of industrial production, these construction pieces are low cost and show a high demand in the local masonry market, therefore, their thermo-physical characteristics largely build the thermal envelope of “Cucuteña”. This research comparatively evaluates the thermal behavior of four types of ceramic blocks with different perforations, applying the finite element method in thermal simulations that consider a conductivity of 0.407 W/m°C in the ceramic to establish the influence of the shape on the temperature distribution and heat flow profiles of each piece subjected to environmental conditions of a warm semi-arid climate, with average maximum temperatures of 33 °C and an average maximum solar radiation of 796.8 Wh/m² under extreme climatic conditions in the city of San Jose de Cúcuta, Colombia. The results of the study allow identifying the ceramic block of 6 rectangular holes as the product that, due to its physical characteristics, presents a better alternative to be applied in constructions that seek thermal efficiency.

Fluid-dynamic study of the behavior of the air inside a textile Stenter

Parra, J W | 2021-09-03

In the textile industry, drying is one of the most important processes. This process requires large investments and high energy consumption, which generates high costs for companies in this sector. In this work, a modeling of the behavior of the air was carried out in a textile Stenter, under real operating conditions through the development of fluid-dynamic simulations. For the computational modeling of the problem, a 3D geometry was constructed based on measurements taken from an injector of a textile Stenter. The standard k-ε turbulence model was used in the turbulent flow solution. The equations of the model were solved numerically using the finite element method. The standard k-epsilon turbulence model proved to be a model capable of reproducing the behavior of the air in the injectors of the textile Stenter.

Factors shaping the COVID‑19 epidemic curve: a multi‑country analysis

Su Yeon, Jang | 2021-10-02

Lockdown measures are the backbone of containment measures for the COVID-19 pandemic both in high-income countries (HICs) and low- and middle-income countries (LMICs). However, in view of the inevitablyoccurring second and third global covid-19 wave, assessing the success and impact of containment measures on the epidemic curve of COVID-19 and people’s compliance with such measures is crucial for more effective policies. To determine the containment measures influencing the COVID-19 epidemic curve in nine targeted countries across high-, middle-, and low-income nations.

Imaginaries Of The Venezuelan Migrant From The Narratives Of A Border Community In Cúcuta, Colombia

Urbina Cárdenas, Jesús Ernesto | 2022-11-09

This text addresses the phenomenon of migration of the Venezuelan population to Colombia from the narratives of inhabitants of the border area of the Corregimiento de la Parada, located in the city of Cúcuta. Through these narratives the researchers show the atavistic imaginaries about the Venezuelan migrant through fivecategories: "the borders", "friend/enemy", "good/bad", "scapegoat", "an eye for an eye, a tooth for a tooth". An interpretative methodology is used, taking symbolic interactionism as a reference, insofar as it allows us to understand the process of creation and assignment of meanings by the residents of this area. The results show violence as a method to justify xenophobic attitudes against Venezuelan migrants.

Processes Of Educational Inclusion In Times Of Crisis

Vergara Fregoso, Martha | 2022-11-09

The pandemic marked society and, therefore, educational institutions, since preventive measures revealed large gaps and differences, and led to rethink the role of the school today, to rethink its constitution and redirect its actions towards a renewed entity, with new positions, new approaches and commitments, in order to respond to current needs and, even more so, to serve students with disabilities. This paper represents a research advance in which an analysis is made of the perspective, policies and strategies that the University of Guadalajara implements to guarantee inclusive education, and some of the effects generated in higher education students as a result of the COVID-19 pandemic; in particular, emphasis is placed on the effects that the situation has had on students with disabilities. For this research, some interviews were conducted with blind students from the same institution, in order to learn about their experiences during the health emergency.

Mathematical Modelling As A Tool To Understand Everyday Situations

Prada Núñez, Raúl | 2022-11-09

This research reports the effects derived from the application of mathematical modelling in classroom work within the development of mathematics classes, which allowed the resignification of the concept of linear function, making use of various semiotic registers of representation applied to a wide range of everyday situations. The fieldwork was based on the application of a didactic sequence to two groups of ninth grade students from a public educational institution located in the capital city of northeastern Colombia. The students were expected to build a mathematical model that would fit the data provided framed in the situations in context in order to contribute to the re-signification of mathematical knowledge. The results show that the practice of modelling favours the motivation of students in relation to mathematical knowledge, giving it meaning and significance when confronted with real situations.

Formative Meaning Of Teaching Practice

Freire Tigreros, María Eufemia | 2022-11-09

The perception that four teachers and one hundred students have of their teaching practices with theoretical support was explored, which served as a basis for discussion, of the incidence of teacher training on the educational task, from a qualitative research, inductive method, descriptive-interpretative approach. To address subjective aspects about before, during and afterthe practice, a non-participant observation guide and a student questionnaire were used as instruments. The results allowed recovering the contributions in two constructs: the theoretical meaning and the formative meaning. Here we present the analysis of the formative meaning that contemplates the subcategories of New Forms of Pedagogical Relationship (NFRP) articulated to critical dialogicity and Collaborative Work (CT) and derived from it, the importance of enhancing the formative nature of research.

¿Los Foráneos? Relatos de Población Receptora de Migrantes en una Ciudad Fronteriza

Bayona Sanabria, Tatiana Torcoroma | 2022-11-09

This research article shows a broad analysis of the situation of migrants in the city of Cúcuta - Norte de Santander (Colombia) and the representations that the receiving citizens have in this border context. The methodological approach of this study was framed from the qualitative-hermeneutic paradigm where the life story was used as a basis for collecting information. The results of the research show that the discourses of the subjects under study legitimise violent actions towards the Venezuelan migrant population. Furthermore, it shows that in the border municipalities, residents naturalise the current situation, to the extent that it seems that the events that occur in this border context are isolated from the reality of those who do not migrate, describing them as "something normal".

Education And Prevention: Strategies To Prevent Adolescent Suicide

Gómez, Guillermo | 2023-05-01

Gatekeepers Training (GKT) is one of the most widely used and disseminated programs worldwide to train personnel in suicide prevention. The purpose of the program is to acquire the necessary skills and competencies to detect psychoemotional and mental health problems that could lead to self-destructive behaviors. In this research work, the level of risk related to suicide was evaluated by means of the ISO-30 psychometric test in high school students, then the effectiveness of a gatekeeper training program applied in the Tepatitlan Regional Preparatory School (TRPS) andsome of its modules was evaluated. The results of the ISO-30 psychometry showed that 64.5% of the students evaluated have a high-riskfactor for suicide related to the inability to cope with emotions. In addition to the above, a statistically significant difference was found (Mann-Whitney U Statistics = 4322.000; p0.001) in the level of competence of the participants in relation to a pre-training evaluation.It is important to note that the effect of the difference found is strong (Rosenthal’sr=0.67) so it is concluded that the GKT drastically improved the skills and competencies of the participants.

Tuberculosis in the colombian-venezuelan border: geospatial distribution

Ruiz Roa, Silvia Liliana | 2022-09-30

The geospatial distribution of pulmonary and extrapulmonary tuberculosis (TB) morbidity in the municipality of Cucuta in 2019 and 2020 was described by the Kulldorff method using the geographic location and reporting date of incident TB cases. The unit of analysis was the event reported to the National Epidemiological Surveillance System (SIVIGILA). A total of 607 cases were identified in 392 neighborhoods distributed in ten communes. Most cases of pulmonary TB were reported in the northern commune, with the El Salado neighborhood being the most affected repeatedly. Incident cases of extrapulmonary TB did not show patterns of repetition in the distribution between spatial and temporal units. Strategies to mitigate and control the spread of pulmonary infection should prioritize the western region.