16 research outputs found
Depletion forces near a soft surface
We investigate excluded-volume effects in a bidisperse colloidal suspension
near a flexible interface. Inspired by a recent experiment by Dinsmore et al.
(Phys. Rev, Lett. 80, 409 (1998)), we study the adsorption of a mesoscopic bead
on the surface and show that depletion forces could in principle lead to
particle encapsulation. We then consider the effect of surface fluctuations on
the depletion potential itself and construct the density profile of a polymer
solution near a soft interface. Surprisingly we find that the chains accumulate
at the wall, whereas the density displays a deficit of particles at distances
larger than the surface roughness. This non-monotonic behavior demonstrates
that surface fluctuations can have major repercusions on the properties of a
colloidal solution. On average, the additional contribution to the Gibbs
adsorbance is negative. The amplitude of the depletion potential between a
mesoscopic bead and the surface increases accordingly.Comment: 10 pages, 5 figure
Lessons learned from using art forms for the representation of local climate information
Lessons learned from using art forms for the representation of local climate information
Natureza dos deuses e divindade da natureza: reflexões sobre a recepção antiga e moderna do antropomorfismo divino grego
A dificuldade em admitir-se o antropomorfismo dos deuses aparece na Grécia a partir da época arcaica, com os primeiros textos em prosa dos pensadores pré-socráticos. Neste estudo definirei as principais características dessa reflexão crítica sobre os limites do antropomorfismo, bem como a recusa dos intérpretes modernos em aceitar o antropomorfismo grego como uma experiência religiosa autêntica. Alguns fragmentos de Heráclito de Éfeso serão citados como exemplo da sabedoria dos jônios na época arcaica.<br>The difficulty in admitting divine anthropomorphism appears in Greece from the archaic epoch onwards with the first prose texts of the pre-Socratic thinkers. In this study I will define the main characteristics of this critical reflexion about the limits of anthropomorphism, as well as the modern scholars' refusal to accept it as an authentic religious experience. Some fragments of Heraclitus of Ephesus will be cited as an example of the Ionian wisdom of the archaic epoch