Las tecnologías de la información y comunicación y su incidencia en el desempeño docente en una escuela de educación básica. Guayaquil, 2018

La investigación denominada “Las tecnologías de la información y comunicación y su incidencia en el desempeño docente, de una escuela de educación básica. Guayaquil, 2018”, tuvo como objetivo determinar la incidencia de las tecnologías de la información y comunicación en el desempeño docente de la Escuela de Educación Básica Organización de Estados Americanos, Guayaquil. 2018. El estudio planteó la hipótesis que afirmaba que las tecnologías de la información y comunicación inciden significativamente en el desarrollo docente de la Escuela de Educación Básica Organización de Estados Americanos, Guayaquil, 2018. La población de estudio estuvo conformada por 11 docentes de la Escuela de Educación Básica Particular Organización de Estados Americanos, el diseño de este estudio fue una investigación correlacional – causal, la recolección de la información se realizó mediante la aplicación de dos cuestionarios, uno para medir la variable tecnologías de la información que constó de 32 ítems, utilizando la escala de valoración ordinal que iba de nunca a siempre (1 – 5), y su confiabilidad obtenida por medio del Alfa de Cronbach fue de 0,926; y para la variable desempeño docente, el instrumento constaba de 30 ítems, utilizando la misma escala de valoración antes mencionada, con una confidencialidad de 0,932. Para el procesamiento de información se utilizó el software SPSS versión 2.2. Los resultados se presentaron a través de tablas de contingencia y los estadísticos rho. Los resultados correlacionales de la tabla 7 explican que dando los valores sig 0,142, R 0,130 y rho 0,473; alcanzados se niega la incidencia significativa. La investigación concluye que las tecnologías de la información y comunicación no incide significativamente en el desempeño docente de la Escuela de Educación Básica Particular Organización de los Estados Americanos, Guayaquil, 201

Air pollution in a tropical city: the relationship between wind direction and lichen bio-indicators in San Jos\'e, Costa Rica

Lichens are good bio-indicators of air pollution, but in most tropical countries there are few studies on the subject; however, in the city of San Jos\'e, Costa Rica, the relationship between air pollution and lichens has been studied for decades. In this article we evaluate the hypothesis that air pollution is lower where the wind enters the urban area (Northeast) and higher where it exits San Jos\'e (Southwest). We identified the urban parks with a minimum area of approximately 5 000m2 and randomly selected a sample of 40 parks located along the passage of wind through the city. To measure lichen coverage, we applied a previously validated 10 x 20cm template with 50 random points to five trees per park (1.5m above ground, to the side with most lichens). Our results (years 2008 and 2009) fully agree with the generally accepted view that lichens reflect air pollution carried by circulating air masses. The practical implication is that the air enters the city relatively clean by the semi-rural and economically middle class area of Coronado, and leaves through the developed neighborhoods of Escaz\'u and Santa Ana with a significant amount of pollutants. In the dry season, the live lichen coverage of this tropical city was lower than in the May to December rainy season, a pattern that contrasts with temperate habitats; but regardless of the season, pollution follows the pattern of wind movement through the city.Comment: 8 pages, 2 figure

Measurement of the magnetic field of small magnets with a smartphone: a very economical laboratory practice for introductory physics courses

In this work, we propose an inexpensive laboratory practice for an introductory physics course laboratory for any grade of science and engineering study. This practice was very well received by our students, where a smartphone (iOS, Android, or Windows) is used together with mini magnets (similar to those used on refrigerator doors), a 20 cm long school rule, a paper, and a free application (app) that needs to be downloaded and installed that measures magnetic fields using the smartphone's magnetic field sensor or magnetometer. The apps we have used are: Magnetometer (iOS), Magnetometer Metal Detector, and Physics Toolbox Magnetometer (Android). Nothing else is needed. Cost of this practice: free. The main purpose of the practice is that students determine the dependence of the component x of the magnetic field produced by different magnets (including ring magnets and sphere magnets). We obtained that the dependency of the magnetic field with the distance is of the form x-3, in total agreement with the theoretical analysis. The secondary objective is to apply the technique of least squares fit to obtain this exponent and the magnetic moment of the magnets, with the corresponding absolute error.AB thanks the Vicerectorship of Information Technologies of the University of Alicante (Spain) and the help of GITE-09006-UA. IE is grateful to the Ministry of Economy and Competitiveness for help provided through the project DPI2012-32994

A Review of the Preservation of Hard and Semi-Hard Cheeses: Quality and Safety

Cheese is a dairy product with potential health benefits. Cheese consumption has increased due to the significant diversity of varieties, versatility of product presentation, and changes in consumers’ lifestyles. Spoilage of hard and semi-hard cheeses can be promoted by their maturation period and/or by their long shelf-life. Therefore, preservation studies play a fundamental role in maintaining and/or increasing their shelf-life, and are of significant importance for the dairy sector. The aim of this review is to discuss the most effective methods to ensure the safety and sensory quality of ripened cheeses. We review traditional methods, such as freezing, and modern and innovative technologies, such as high hydrostatic pressures, chemical and natural vegetable origin preservatives, vacuum and modified atmosphere packaging, edible coatings and films, and other technologies applied at the end of storage and marketing stages, including light pulses and irradiation. For each technology, the main advantages and limitations for industrial application in the dairy sector are discussed. Each type of cheese requires a specific preservation treatment and optimal application conditions to ensure cheese quality and safety during storage. The environmental impact of the preservation technologies and their contribution to the sustainability of the food chain are discussed.Financial support was provided by the Basque Government (Research Groups IT944-16). Vitoria-Gasteiz. Spain

Metacognición y aprendizaje por descubrimiento: aplicación al caso de una red infinita de condensadores

Los montajes de condensadores en serie o en paralelo son situaciones que nos permiten enfrentarnos de manera eficiente al aprendizaje del concepto de carga eléctrica almacenada en sus placas y a la diferencia de potencial entre sus armaduras. Los procedimientos estándares para el cálculo de la capacidad equivalente en circuitos con un número considerable de elementos suele causar confusión entre los estudiantes del primer año en un Grado de Ciencias o Ingeniería, el manejo de redes infinitas de condensadores supone entonces un desafío aun mayor, si bien es cierto que es importante que el estudiante conozca los métodos tradicionales de solución también es relevante para su formación científica que sea capaz de plantear soluciones alternativas a los problemas que se le presenten, sobre todo si se sigue un método de instrucción encaminado a la solución de problemas cercanos a su cotidianeidad que requieren de habilidades cognitivas de orden superior. Para ello queremos diseñar, utilizando aprendizaje por descubrimiento, una secuencia didáctica para determinar la capacidad equivalente de una red infinita de condensadores iguales. Esta secuencia considera además del trabajo experimental, la aplicación de un método que propiciará en el estudiante la construcción de una solución no tradicional al cálculo de la capacidad equivalente para una red infinita y finalmente, el planteamiento de una solución analítica. El método propuesto involucra un proceso metacognitivo que podrá ser transferido a otros campos de estudio de la Física.Assembling capacitors in series or in parallel are situations that allow us to deal efficiently with the learning of the concept of electric charge stored on their plates and the potential difference between its frames. The standard procedures for calculating the equivalent capacity in circuits with a large number of elements often cause confusion among freshmen in Science or Engineering Degree, the management of infinite capacitor networks then assumes an even greater challenge, while it is true that it is important that the students learn the traditional methods of solution it is also relevant in their scientific training that they are capable to propose alternative solutions to the problems presented to them , especially if an instructional method aimed to the solution of problems close to their daily life require cognitive abilities of higher order . Therefore, a didactic sequence, using learning by discovery, was designed using to determine the equivalent capacity of an infinite network of identical capacitors. This sequence also considers the experimental work, the application of a method that will lead the student to the construction of a non-traditional solution to the calculation of the equivalent capacity for an infinite network and finally, the approach of an analytical solution. The proposed method involves a metacognitive process that can be transferred to other fields of study of physics.Uno de nosotros (AB) agradece al Vicerrectorado de Tecnologías de la Información de la Universidad de Alicante (Spain) la ayuda GITE-09006-UA. (IE) agradece al Ministerio de Economía y Competitividad la ayuda prestada a través del proyecto DPI2012-32994

Medida del campo magnético de imanes pequeños con un smartphone: una práctica de laboratorio muy económica

Proponemos en este trabajo una práctica barata y muy bien recibida por nuestros estudiantes donde un smartphone (iOS, Android o Windows Phone es irrelevante) se usa junto algunos pequeños imanes, de los que colocamos en la puerta de nuestras neveras, una regla escolar de 20 cm, un papel y una aplicación gratuita (app) para medir el campo magnético utilizando el sensor de campos magnéticos de o magnetómetro que lleva incorporado el smartphone. No se necesita nada más. El costo de esta práctica: 0 euros. El propósito principal de la práctica es determinar la dependencia del campo magnético con la distancia. El objetivo secundario es a través de la técnica de mínimos cuadrados obtener el error del exponente de la distancia y del momento magnético de los imanes, con sus correspondientes errores absolutos. Comprobaremos que el acuerdo con la teoría es excelente.We propose in this work an inexpensive practice and very well received by our students where a smartphone (iOS, Android or Windows Phone is irrelevant) is used together some mini magnets, those that have hung in the door of our fridges, a school rule of 20 cm, a paper and a free application (app) for measuring the magnetic field using the sensor magnetic fields or magnetometer. Nothing else is needed. Cost of this practice: 0 dollars. The main purpose of the practice is to determine the dependence of the magnetic field with distance. The secondary objective is through the technique of least squares to obtain the exponent distance error and the magnetic moment of the magnets, with theirs corresponding absolute error. We will check that the agreement with theory is excellent.Uno de nosotros (AB) agradece al Vicerrectorado de Tecnologías de la Información de la Universidad de Alicante (Spain) la ayuda GITE-09006-UA. (IE) agradece al Ministerio de Economía y Competitividad la ayuda prestada a través del proyecto DPI2012-32994

Creación de cuestionarios avanzados usando la plataforma Moodle

Asumiendo el papel de orientador, el profesor debe además, evaluar el proceso de aprendizaje del estudiante, no para sancionar sus resultados meramente, sino para ayudarle a cumplir objetivos mediante un seguimiento continuo de su trabajo. Así, aunque puedan ser necesarios los exámenes finales, no serán los únicos métodos de evaluación existentes. Para grupos grandes, puede resultar engorroso el excesivo trabajo que conlleva la evaluación continua de un elevado número de estudiantes. Por ello, resulta de gran utilidad hacer uso del módulo cuestionario empleando la plataforma Moodle. En definitiva, si nuestro propósito es usar Moodle para evaluar las competencias adquiridas por un alumno a través de una prueba objetiva o examen, las preguntas denominadas de tipo calculada son muy útiles para generar cuestionarios en esta plataforma virtual. De esta manera, cada alumno tendrá diferentes preguntas, por lo que se puede evitar que se pasen las respuestas ya que deben conocer el procedimiento para obtener la solución a la pregunta. El objetivo principal es aprender no pasar exámenes.Taking on the role of adviser, the teacher must now assess the student ́s learning process, not merely to sanction his results but to help the student achieve his best results through a constant supervision of his work. In this way, even though there may be final exams, these won ́t be the only means of assessment. Sometimes the great amount of work that constant supervision implies may prove to be cumbersome. For this reason it is useful to employ questionnaires using Moodle. In short, if our purpose is to use Moodle to assess the student ́s competence acquired through an exam, calculated question types are very useful to generate questions in this virtual domain. Therefore each student will have different questions and we will avoid situations in which the students share the answers since they will have to know the procedure to arrive at the solution

Polyaza macroligands as potential agents for heavy metal removal from wastewater

Two polyaza macroligands N,N´-bis(2-aminobenzyl)-1,2- ethanediamine (L1) and 3,6,9,12-tetraaza-4(1,2),11(1,2)-dibenzo-1(1,3)- piridinaciclotridecafano (L2) were characterized and investigated for their metal ion extraction capabilities. The nature of all complexes was established by spectroscopic techniques. The equilibrium constants were determined by spectrophotometric and potentiometric techniques and the residual concentration of metals in the solutions by Atomic Absorption Spectrometry (AAS). The capacity of the ligands to remove heavy metals such as Cu(II), Ni(II), Cd(II), Zn(II) and Pb(II) as insoluble complexes was evaluated in wastewater from industrial effluents. These agents showed high affinity for the studied metals. The values of equilibrium constants of the isolated complexes (between 1 x 104 and 2 x 107) demonstrated the feasibility of applying these chelating agents as an alternative to remove heavy metals from industrial effluents

Estudio experimental de la inducción electromagnética entre dos bobinas: dependencia con la corriente eléctrica

En este artículo se muestran un conjunto de sencillas experiencias de laboratorio que ilustran el fenómeno de la inducción electromagnética. El dispositivo experimental, análogo a un transformador, está formado por dos bobinas magnéticamente acopladas conectadas a un generador de corriente alterna sinusoidal de frecuencia variable. Midiendo la tensión inducida en la bobina del secundario en función de la corriente que hay en la bobina del primario se obtiene una dependencia lineal. Los resultados obtenidos concuerdan bastante bien, teniendo en cuenta los intervalos de error, con las predicciones teóricas de la ley de Faraday-Henry. Para la predicción teórica se ha tenido en cuenta el tamaño finito de ambas bobinas calculando el flujo magnético mediante una sencilla integral.In this paper, it is shown a set of simple experiences that inform about the phenomenon of electromagnetic induction. The electrical assembly is made of two coils magnetically coupled, analogous to an electrical transformer, connected to a variable frequency AC generator. If we measure the voltage induced in the secondary coil based on the current of the primary coil it is obtained a linear dependence. The obtained results agree quite well with, considering the error ranges, the theoretical predictions of the Faraday-Henry’s law. In the theoretical predictions we have also taken into account the finite size of both coils calculating the magnetic flux through an easy integral.Uno de los autores, A. Beléndez, agradece al Vicerrectorado de Tecnologías de la Información de la Universidad de Alicante el apoyo prestado a través del proyecto GITE- 09006-UA

Optimization of Modified Atmosphere Packaging for Sheep’s Milk Semi-Hard Cheese Wedges during Refrigerated Storage: Physicochemical and Sensory Properties

Modified atmosphere packaging (MAP) has become a good potential strategy to retain quality throughout the shelf life of perishable foods. The aim of this work was to evaluate different packaging atmospheres on semi-hard protected designation of origin Idiazabal cheese wedges. Six different packaging treatments (air, vacuum, and CO2/N2 gas mixtures in the ratio of 20/80, 50/50, 80/20, and 100/0% v/v, respectively) were studied. Changes in gas headspace composition, cheese gross composition, weight loss, pH, acidity, colour, and textural and sensory properties were investigated during 56 days of refrigerated storage at 5 ± 1 °C. MAP was the most effective preserving technique compared to air- and vacuum-packaging treatments. The cheese characteristics with the greatest discriminating weight in the preservation techniques were paste appearance, holes, flavour, a* (redness) and b* (yellowness) colour parameters, and slope to hardness. Air-packaged cheeses, on 35 day, presented a mouldy flavour. Vacuum packaging affected paste appearance (greasy, plastic marks, and non-homogeneous colour) and holes (occluded and unnatural appearance) starting after 14 packaging days. MAP mixtures with CO2 concentration between 50/50 and 80/20% CO2/N2 (v/v) are recommended to ensure sensory quality and stability in the distribution of these raw sheep-milk cheese wedges.The Basque Government (Consolidated Research Group IT944-16 and IT1568-22) provided financial support. Vitoria-Gasteiz, Spain