Search results for "EPA"

Perfil de la educación física y sus profesores desde el punto de vista de los alumnos.

2007

El objetivo de este trabajo ha sido conocer el pensamiento de los alumnos sobre la Educación Física y sus profesores. Para ello, 788 estudiantes de Educación Secundaria Obligatoria (337 alumnos y 451 alumnas) han respondido a un cuestionario abierto en el que se les preguntaba qué es lo que más y lo que menos les gusta de EF, cómo se imaginan a su profesor/a ideal de EF, y las tres características más importantes que debería tener su profesor o profesora de EF. Tras un análisis de contenido de las respuestas de los alumnos se concluye que las cosas que más les gustan de EF son las prácticas de deportes de equipo y los juegos y actividades variadas; las cosas que menos les gustan son los eje…

Active repair technology applied to delaminated composite structures

2009

The main target of the present paper is represented by the fracture mechanics charac-terization of delaminated composite structures actively repaired through piezoelectric patches. A boundary element code, formulated for anisotropic piezoelectric solids, including, as limiting case, the applicability to linear elastic anisotropic materials has been then imple-mented. The modeling of the delaminated composite structures as well as of the assembled structures, made of the damaged components and the patches, has been achieved through the multidomain technique. Moreover, to take into account for the adhesive layer between the host structures and the piezoelectric patches, a "spring-model" has b…

BE contact analysis of delamination cracks actively repaired trhough piezoelectric active patches

2009

Analysis of piezoelectric active patches performances by boundary element techniques

2008

This paper presents the analysis of active piezoelectric patches for cracked structures by Boundary Element Method. A two dimensional boundary integral formulation based on the multidomain technique is used to model cracks and to assemble the multi-layered piezoelectric patches to the host damaged structures. The fracture mechanics behavior of the repaired structures is analyzed for both perfect and imperfect interface between patches and host beams. The imperfect interface, representing the adhesive between two different layers, is modeled by using a “Spring Model” that involves linear relationships between the interface tractions, in normal and tangential directions, and the respective di…

Application of LA-ICP-MS as a rapid tool for analysis of elemental impurities in active pharmaceutical ingredients.

2014

The control of inorganic contaminants in active pharmaceutical ingredients has a significant role in the quality control of drug products. The concentration limits for metal residues in drug products have been defined by various regulatory guidelines. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful and fast analytical technique for multi-elemental analysis. A disadvantage in using LA-ICP-MS method is the lack of matrix reference materials for validation and calibration purposes. This article focuses on the handling strategy of laboratory-made matrix calibration standards for the quantification of elemental impurities in an active pharmaceutical ingredie…

Pefloxacine mesilate- and ofloxacin-loaded polyethylcyanoacrylate nanoparticles: characterization of the colloidal drug carrier formulation.

1995

The entrapment of fluoroquinolones, perfloxacine mesilate (PFX) and ofloxacin (OFX), in polyalkylcyanoacrylate (PECA) nanoparticles could offer some advantages for their biological application; for examples, increasing their bioavailability, controlling the drug time-release in blood, and reducing the formation of bacterial resistance. To load these two drugs in PECA polymeric bulk, the incorporation or adsorption method was performed. These two methods were capable of influencing nanoparticle size, molecular weight, release profile, and drug–polymer association. The incorporation method, particularly for the OFX system, achieved PECA nanoparticle suspensions with a mean size value three ti…

Strategies for Active Learning to Improve Student Learning and Attitudes Towards Physics

2021

Over the last several years, active learning methods and strategies have received considerable attention from the educational community and are commonly presented in the related literature as a credible solution to the reported lack of efficacy of more “traditional” educative approaches. Research has shown that a possible factor is the strongly contextualized nature of active learning that focuses on the interdependence of situation and cognition. In this paper, we report the results of a Symposium with different contributions in the field of research on active learning. We start with a system analysis of the mental processes involved in learning physics which explains how active learning i…

Contra la patologización intensiva en términos de derechos humanos: Activismo gordo en Argentina

2020

This work addresses the way in which Argentine Fat Activism has developed, in recent years, the demand for depathologization of fatness, taking elements from critical discourses on the health of fat people to frame them in a perspective typical of the Human Rights. First, the contemporary fat body is described in terms of stigma and discrimination, especially in the health field. Then, they refer to a series of critical positions on the pathologization and medicalization of fatness from the biomedical perspective, Fat Studies and Fat Activism. Lastly, a series of interventions that the Argentine activist collective Taller Hacer la Vista Gorda produced between 2017 and 2020 were considered, …

Activity coefficients and Donnan coion exclusion in charged membranes with weak-acid fixed charge groups

1998

Abstract We have studied theoretically the effects that the dissociation equilibrium of weak-acid fixed charge groups (e.g. carboxyl groups) exerts on the mean activity coefficients in charged membranes using a Donnan formalism. The model calculations indicate that unless carbon dioxide is excluded from the external aqueous solution, the pH of the membrane solution can be low enough to affect significantly the effective fixed charge concentration and the coion exclusion when the membrane fixed charge concentration is high compared with the external solution salt concentration. Although this problem was already pointed out in previous studies, the possibility that the pH and salt concentrati…

Prediction of Maxwell – Stefan diffusion coefficients in polymer – multicomponent fluid systems

2014

Abstract Calculations of mass fluxes in multicomponent fluids based on the system of generalized Maxwell–Stefan equations (GMSE) is preferably used because Maxwell–Stefan (M–S) diffusion coefficients are symmetrical and have a clear physical meaning, as they reflect the binary friction forces between compounds in the system. For the calculation of the mass transport of a multicomponent fluid in the polymer basing on GMSE, it is necessary to have M–S diffusion coefficients. This paper proposes a method that allows their calculation using widely available self-diffusion coefficients and binary diffusion coefficients for infinitely diluted mixtures. The proposed method was compared with the me…