Las actitudes de los estudiantes frente al estudio de las matemáticas, en los programas de Administración de la Corporación Universitaria Minuto de Dios, Centro Regional Pasto

A continuación se describe la experiencia de los investigadores, quienes en su revisión bibliografía pertinente, encuentran que las creencias y actitudes de los estudiantes hacia las matemáticas tienen relación con el proceso de enseñanza de esta ciencia. Por lo cual, recurren a la herramienta Mapa de Empatía, conocida en el ámbito empresarial y articulada con el contexto pedagógico mediante el trabajo de Inés María Gómez Chacón, que se adapta y valida con el apoyo de profesionales de psicología del área de Bienestar Universitario de la institución. Este recurso se aplica a una muestra de estudiantes de tercer semestre de los tres programas de Administración y se identifican creencias, habilidades, aspectos culturales, motivacionales y de frustración con los que viven los estudiantes de Uniminuto, no solo en la etapa universitaria y en el rol de aprendices, sino también en etapas de formación previas y en los espacios propios de su cotidianidad

A Java based simulation for basic control

7th IFAC Symposium on Advances in Control Education 21/06/2006 MadridIn this paper we present a java based simulator for control education in basiccourses. The application has been developed using the well known tool Easy JavaSimulation.The objective of the application is to help the student to learn the design of classiccontrollers such as P,PI, PID, etc testing the tuning procedures to control the position ofan antenna controlled by a DC motor. Thus the application allows the student to choosethe parameters of the antenna and the DC motor, to choose the controller to be used andits parameters and finally to simulate the closed loop system observing the evolution ofthe signals as well as a 3-D view. Furthermore, in order to show the real behavior of thesystem, dead zone, saturation, disturbances and non-linearities can be added to the model.This application has been used by the authors to teach a basic control course at EscuelaSuperior de Ingenieros (University of Seville) as virtual laboratory.Moreover, since the application is java based, this can be used by the students from theauthors’ web pages and this can also be installed in the student’s laptop (whichever theplatform is) by downloading it from the authors web page (Limon and Salas, 2003Ministerio de Ciencia y Tecnología DPI2004-07444Ministerio de Ciencia y Tecnología DPI2003-0042

The influence of heavy goods vehicle traffic on accidents on different types of Spanish interurban roads

This paper illustrates a methodology developed to analyze the influence of traffic conditions, i.e. volume and composition on accidents on different types of interurban roads in Spain, by applying negative binomial models. The annual average daily traffic was identified as the most important variable, followed by the percentage of heavy goods vehicles, and different covariate patterns were found for each road type. The analysis of hypothetical scenarios of the reduction of heavy goods vehicles in two of the most representative freight transportation corridors, combined with hypotheses of total daily traffic mean intensity variation, produced by the existence or absence of induced traffic gives rise to several scenarios. In all cases a reduction in the total number of accidents would occur as a result of the drop in the number of heavy goods transport vehicles, However the higher traffic intensity, resulting of the induction of other vehicular traffic, reduces the effects on the number of accidents on single carriageway road segments compared with high capacity roads, due to the increase in exposure. This type of analysis provides objective elements for evaluating policies that encourage modal shifts and road safety enhancements

First helminthological data on the Iberian adder, Vipera seoanei.

The helminth fauna present in the gut contents of Iberian adders, Vipera seoanei (Squamata: Viperidae), were characterised and analysed in respect to biological and eco-geographic factors that may affect the occurrence and diversity of helminths in this species. A total of 317 samples of preserved stomachs and intestines, covering the distributional range of V. seoanei, were examined. Similar to other Vipera species from the Iberian Peninsula, the helminth fauna was also impoverished in V. seoanei, but unlike other Vipera species from Central and East Europe, helminths were mostly found in adult vipers, and occurred in vipers located at the periphery of the species range, characterised by low elevation, high temperature and precipitation levels, and abundant pastures

Probing the heavy Higgs boson production and decay H0H_0 of the Bestest Little Higgs Model at the LHC and the FCC-hh

In the Bestest Little Higgs Model (BLHM) scenario, we analyze the branching ratios and production cross-section of the heavy Higgs boson $H_0$. The analysis is performed at the tree level and the one-loop level. In addition, we present results of the possible production of the heavy Higgs boson $H_0$ via gluon fusion for the center-of-mass energies and the integrated luminosities of the LHC, HE-LHC, HL-LHC, and FCC-hh. Our results show a very optimistic scenario for studying the $H_0$ scalar predicted by the BLHM and for the energies and luminosities of current and future hadron colliders.Comment: 24 pages, 10 figures. arXiv admin note: text overlap with arXiv:2302.11143, arXiv:2208.09090, arXiv:2202.1273

Prevalence and Risk Factors of Mastitis among Dairy Buffaloes from the Departments of Antioquia and Córdoba, Colombia

Background: Mastitis is the most common disease among dairy buffaloes worldwide, and it significantly affects the economic profitability of buffalo farms as well as animal welfare and public health. Methods: This study was conducted between 2018 and 2019 at the Colombian departments of Antioquia and Córdoba, where 41% of the country’s total buffalo population is concentrated. Overall, 1,018 dairy buffaloes, including 603 in Antioquia and 415 in Córdoba, distributed among 11 farms, were assessed in the study. These animals were evaluated using the California mastitis test (CMT) and somatic cell count (SCC) to determine the presence of subclinical mastitis (SM). They were considered positive for SM when the results of CMT were higher than traces and SCC was >200,000 cells/mL. Results: The total prevalence of the disease was 7.9%, and microbiological culture was performed on the samples obtained from the SM-positive animals. The main isolated bacterium was coagulase-negative Staphylococcus. Furthermore, risk factors affecting milking routine, hygiene, and farm facilities were determined. Manual milking, milking in the barn, non-disinfection of milkers' hands, etc., were identified as risk factors for the disease. Conclusion: To the best of our knowledge, this is the first large-scale study of mastitis among buffaloes in Colombia

Desarrollo de un composite ácido cáprico/ácido mirístico/soporte poroso para el almacenamiento de energía térmica

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMEN: Un composite constituido del eutéctico binario ácido cáprico/ácido mirístico (CA:MA) y un soporte mineral poroso colombiano fue desarrollado para aplicaciones de almacenamiento de energía térmica alrededor de los 26 °C. Diferentes porcentajes de impregnación de CA:MA (25%, 35% y 40%) en el soporte fueron estudiados para determinar los valores óptimos en términos de filtración. El mejor composite obtenido, con el 35% de CA:MA y menos del 1,5% de filtración, fue caracterizado térmicamente mediante calorimetría diferencial de barrido (DSC), así mismo, se evaluaron su conductividad térmica, capacidad calorífica y estabilidad térmica a través de las técnicas del hilo caliente, calorimetría diferencial de barrido modulada (MDSC) y ciclado térmico, respectivamente.ABSTRACT: A composite consisting of the binary eutectic capric acid/myristic acid (CA:MA) and a Colombian porous mineral support was developed for thermal energy storage applications around 26 °C. Different percentages of CA:MA impregnation (25%, 35% and 40%) in the support were studied to determine the optimal values in terms of leakage. The best composite obtained, with 35% CA:MA and less than 1.5% of leakage, was thermally characterized by differential scanning calorimetry (DSC). Besides, its thermal conductivity, heat capacity and thermal stability were evaluated through the techniques of hot wire, modulated differential scanning calorimetry (MDSC) and thermal cycling, respectively.info:eu-repo/semantics/publishedVersio

Polyurethanes from modified castor oil and chitosan. Synthesis, characterization, in vitro degradation, and cytotoxicity

[EN] Polyurethanes (PUs) from castor oil (CO), modified CO (MCO) by transesterification reaction, isophorone diisocyanate (IPDI) in an NCO/OH ratio equal to 1, and chitosan (CS) were synthesized to assess their potential as biomaterials. PUs were characterized by Fourier transform infrared spectroscopy, hydroxyl value (ASTM D1957), thermogravimetric analysis, Shore A hardness (ASTM D2240), and scanning electronic microscopy (SEM). Also, contact angle, water retention and in vitro degradation in PBS, and cell viability on fibroblast were performed. The hydroxyl value confirms CO modification, and IR analysis confirms urethane bond formation. The thermal assay does not show new degradation stages and polyol with a high functionality had better hardness performance due to the increase in cross-linking. The micrograph shows micro-phase separation of both polymers. The contact angle shows the hydrophobic surface with an angle over 65°, and the CS and polyol type do not affect swelling and in vitro degradation due to phase separation between both polymers. The cell viability was over 70% in all cases, and solid polymers and degradation products involve non-cytotoxic effects on the samples. The results suggest a potential for these formulations in the biomedical field.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Universidad de La Sabana under Grant number ING-160-2015. Also, Jose A. Gomez-Tejedor and Ana Valles-Lluch acknowledge the support of the Spanish Ministry of Economy and Competitiveness (MINECO) through the project DPI2015-65401-C3-2-R (including the FEDER financial support).Arévalo-Alquichire, S.; Ramírez, C.; Andrade, L.; Uscategui, Y.; Diaz, LE.; Gómez-Tejedor, JA.; Vallés Lluch, A.... (2018). Polyurethanes from modified castor oil and chitosan. Synthesis, characterization, in vitro degradation, and cytotoxicity. Journal of Elastomers and Plastics. 50(5):419-434. https://doi.org/10.1177/0095244317729578S41943450

APPLICATION OF A NEW TECHNICAL OF ACOUSTIC TOMOGRAPHY FOR THE VISUALIZATION AND ESTIMATION OF THE MICROFRACTURES IN OUTCROP SAMPLES

This work presents the development of a methodology to estimate microfractures density in rocks, using acoustic tomography technique. The piezoelectric crystals were used as transductors for the generation of the acoustic shear kind waves, through study cores. The propagation time of the wave is obtained using digital signal processing in MATLAB and finally the distances of each paths is obtained, thus the wave velocity values are stored in numerical arrays. The technique used in this work is to perform acoustic tomography in function of the shear wave velocity, where the rock matrix and microfractures are differentiated and analyzed from contrasts of velocities. The tomographic images are generated through rendering matrices of velocity in MATLAB. In order to validate this research was necessary to use synthetic cements plugs as controlled models, where the discontinuity was simulated through hollow inclusions made with rubber prototypes; finally the obtained results show a maximum of 7.06% of error, baseing the reliability of the generated technique.Este trabajo presenta el desarrollo de una metodología para estimar el volumen de microfracturamiento en rocas, utilizando la técnica de tomografía acústica. Se utilizaron cristales piezoeléctricos como transductores para la generación de ondas acústicas secundarias o de corte a través de muestras de estudio. El tiempo de propagación de la onda es obtenido utilizando tratamiento digital de señales en MATLAB y finalmente se obtiene las distancias de cada una de las trayectorias entre los cristales, de esta manera se almacenan los valores de velocidad de onda en arreglos numéricos matriciales. La técnica empleada en este trabajo consiste en realizar tomografía acústica en función de la velocidad de la onda de corte, donde se logra diferenciar la matriz y las microfracturas de las rocas analizadas, a partir del contraste de las velocidades. Las imágenes tomográficas se generan a través de la renderización de las matrices de velocidades en MATLAB. Para poder validar esta investigación fue necesario utilizar plugs sintéticos de concreto como modelos controlados, donde se simularon discontinuidades por medio de inclusiones huecas hechas con prototipos de cauchos; finalmente los resultados obtenidos, muestran un error máximo de 7.06 % fundamentando la confiabilidad de la técnica generada