308 research outputs found
On the influence of climate change on the heliothermal index: Circuito das Frutas, São Paulo (Brazil).
Alcances y limitaciones actuales de la actividad experimental en escuelas de Enseñanza Media de la provincia Santiago de Cuba: criterios de alumnos y profesores
El propósito de este estudio es explorar el estado actual de desarrollo de las actividades experimentales en la asignatura de Física en escuelas de Enseñanza Media de la provincia de Santiago de Cuba ya que constituye un aspecto medular en la construcción del conocimiento científico. Para la recogida de la información se utilizaron dos instrumentos: una encuesta y una entrevista que fueron aplicadas a 268 alumnos y 18 profesores de cinco escuelas con entornos socioculturales diferentes. Los datos obtenidos de las encuestas de ambos sujetos están referidos a: la existencia o no de infraestructura de laboratorio en las escuelas, las características de sus participaciones en los laboratorios y la frecuencia de realización de los mismos. Complementan esta información sus opiniones expresadas en las respuestas a las entrevistas, donde se destaca el papel que atribuyen a los experimentos en el proceso de enseñanza-aprendizaje. Los resultados indican un incremento en la motivación y en la asimilación de los contenidos por parte de los alumnos que participaron en las demostraciones experimentales en las escuelas con infraestructura de laboratorio. Se manifiestan también limitaciones en el orden material con énfasis en las escuelas más alejadas del centro de la ciudad de Santiago de Cuba y de preparación de los profesores para una eficiente utilización del instrumental que poseen en función de la docencia.The purpose of this study is to explore the current developmental status of experimental activities within the subject of physics in Middle Schools in the Santiago de Cuba Province, which constitutes a key aspect in the attainment of scientific knowledge. Two different tools were used in the information gathering process: one poll and a series of iinterviews involving 268 students and 18 professors from five schools of diverse socio-cultural environments. The resulting data relates to: the availability - or not - of lab infrastructure at schools; the type of lab participation; and its frequency. This information is complemented by the opinions expressed in the responses to the interviews where the role attributed to experimental activity in the teaching-learning process is highlighted. The results show an increment in motivation and subject learning on the part of the students when they have access to experimental demonstrations at schools with lab infrastructure. Other limitations observed, especially at schools further away from Santiago de Cuba, were related to the lack of material resources and the preparation of teachers in relation to their utilization of available resources in the teaching function.CAPES/MES (109/10
Effects of yeast based prebiotics as replacers to antimicrobial growth promoters in broilers diets.
Optical properties of amorphous, erbium-doped yttrium alumino-borate thin films
In this paper, we report on the optical characterizations of erbium-doped yttrium alumino-borate glassy thin films prepared by the polymeric precursor and sol–gel routes and the spin-coating technique. High quality planar waveguides were produced by a multilayer processing of Y1−xErxAl3(BO3)4 compositions with x = 0.02, 0.05, 0.10, 0.30, and 0.50. Their optical properties were investigated using transmission, photoluminescence, and m-lines spectroscopy, whereas high resolution scanning electron microscopy (HR-SEM) was applied to check film thickness and surface homogeneity. The refractive indices determined from transmission and m-lines spectroscopy are in good agreement just like the film thickness measured by HR-SEM and transmission spectroscopy. We observed low propagation losses, together with efficient photoluminescence emission for polymeric precursor thin films, involving low cost and environment friendly reactants.FAPESPCNPqCAPES-COFECUB Brazil–Franc
Evaluación de las representaciones de los conceptos de peso y masa de los alumnos de enseñanza media en São Carlos y región (Brasil) y en la provincia de Santiago de Cuba (Cuba)
The persistence of earlier ideas in scientific knowledge learned at school is a well researched subject. This paper shows the knowledge level related to the concepts of weight and mass held by two separate groups of high school students from distant geographical locations: São Carlos (Brazil) and Santiago de Cuba (Cuba). It shows how difficult it is to distinguishing between those concepts and illustrates the strong influence that ordinary knowledge has over their representations. This allowed us to delineate the conceptual profile related to each concept for both student groups. In addition it is possible to observe the positive effect, measurable in events like the Olympics, over the formation of scientific concepts resulting from additional instruction received by students that show an inclination for physics science.CAPES/MES (No. 109/10
Validação do método de graus-dia para estimar a data de diferenciação da panícula de cultivares de arroz irrigado em condições de lavoura no Rio Grande do Sul.
Estudo das alterações no metabolismo da soja em decorrência da infecção por Aphelenchoides besseyi.
Título em inglês: Study of changes in soybean metabolism due to infection by Aphelenchoides besseyi
Utilização de genes morfogênicos para possibilitar a edição genômica de linhagens tropicais de milho.
Here, we report the successful GE of tropical maize lines using a MRs-based protocol.SBGMP 2023
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