Investigar en Trabajo Social: diferentes experiencias como pasantes de investigación

El presente trabajo se propone compartir tres experiencias de investigación llevadas a cabo por estudiantes (ahora licenciadas) en la Facultad de Trabajo Social de la Universidad Nacional de La Plata, en diferentes proyectos de investigación. Dos de las experiencias de pasantías se enmarcaron en el proyecto de investigación “Seguridad, Violencia y Derechos Humanos. Un estudio de las representaciones sociales en jóvenes y policías”1. La otra pasantía se inserta en el proyecto “Disputas en el espacio público: cultura, política y desigualdades socio-urbanas”2. A su vez, dos de nosotras continuamos nuestro proceso de aprendizaje del oficio de investigar a través de dos becas CIN en el marco de los proyectos de investigación acreditados, mencionados anteriormente. Haremos una breve mención respecto a esto. Por último, analizaremos las experiencias como pasantes de investigación a la luz de los aportes de distintos autores/as, haciendo hincapié principalmente en la comprensión de las competencias, habilidades y destrezas necesarias para desarrollar la práctica investigativa.Eje Teórico-metodológico en Trabajo Social-GT 27: Metodología y Trabajo Social.Facultad de Trabajo Socia

Elasticity in Bubble Rupture

When a Newtonian bubble ruptures, the film retraction dynamics is controlled by the interplay of surface, inertial, and viscous forces. In case a viscoelastic liquid is considered, the scenario is enriched by the appearance of a new significant contribution, namely, the elastic force. In this paper, we investigate experimentally the retraction of viscoelastic bubbles inflated at different blowing rates, showing that the amount of elastic energy stored by the liquid film enclosing the bubble depends on the inflation history and in turn affects the velocity of film retraction when the bubble is punctured. Several viscoelastic liquids are considered. We also perform direct numerical simulations to support the experimental findings. Finally, we develop a simple heuristic model able to interpret the physical mechanism underlying the process

Elasticity in Bubble Rupture

When a Newtonian bubble ruptures, the film retraction dynamics is controlled by the interplay of surface, inertial, and viscous forces. In case a viscoelastic liquid is considered, the scenario is enriched by the appearance of a new significant contribution, namely, the elastic force. In this paper, we investigate experimentally the retraction of viscoelastic bubbles inflated at different blowing rates, showing that the amount of elastic energy stored by the liquid film enclosing the bubble depends on the inflation history and in turn affects the velocity of film retraction when the bubble is punctured. Several viscoelastic liquids are considered. We also perform direct numerical simulations to support the experimental findings. Finally, we develop a simple heuristic model able to interpret the physical mechanism underlying the process

Elasticity in Bubble Rupture

When a Newtonian bubble ruptures, the film retraction dynamics is controlled by the interplay of surface, inertial, and viscous forces. In case a viscoelastic liquid is considered, the scenario is enriched by the appearance of a new significant contribution, namely, the elastic force. In this paper, we investigate experimentally the retraction of viscoelastic bubbles inflated at different blowing rates, showing that the amount of elastic energy stored by the liquid film enclosing the bubble depends on the inflation history and in turn affects the velocity of film retraction when the bubble is punctured. Several viscoelastic liquids are considered. We also perform direct numerical simulations to support the experimental findings. Finally, we develop a simple heuristic model able to interpret the physical mechanism underlying the process

Viscosity of Ring Polymer Melts

We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η_0,linear to their ring counterparts η_0,ring at isofrictional conditions is discussed as a function of the number of entanglements <i>Z</i>. In the unentangled regime η_0,linear/η_0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η_0,linear/η_0,ring = 2. In the entanglement regime, the <i>Z</i>-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < <i>Z</i> < 20, η_0,linear/η_0,ring ∼ <i>Z</i>^1.2±0.3, is weaker than the scaling prediction (η_0,linear/η_0,ring ∼<i> Z</i>^1.6±0.3) and the simulations (η_0,linear/η_0,ring ∼ <i>Z</i>^2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem