24 research outputs found
Liquid 4He: contributions to first principles theory of quantized vortices, thermohydrodynamic properties, and the lambda transition
Liquid 4He has been studied extensively for almost a century, but there are
still a number of outstanding weak or missing links in our comprehension of it.
This paper reviews some of the principal paths taken in previous research and
then proceeds to fill gaps and create an integrated picture with more complete
understanding through first principles treatment of a realistic model that
starts with a microscopic, atomistic description of the liquid. Newly derived
results for vortex cores and thermohydrodynamic properties for a two-fluid
model are used to show that interacting quantized vortices may produce a lambda
anomaly in specific heat near the superfluid transition where flow properties
change. The nature of the order in the superfluid state is explained.
Experimental support for new calculations is exhibited, and a unique specific
heat experiment is proposed to test predictions of the theory. Relevance of the
theory to modern research in cosmology, astrophysics, and Bose-Einstein
condensates is discussed.Comment: 155 pages, 28 figure
Psicoterapia de criança com alopecia areata universal: desenvolvendo a resiliência
Este artigo apresenta um estudo de caso de uma criança portadora de alopecia areata universal, vitiligo e transtorno de ansiedade generalizada, atendida em clínica-escola de psicologia de 2002 a 2007. A abordagem terapêutica adotada foi a psicoterapia de orientação psicanalítica infantil e a orientação sistemática aos pais, objetivando a diminuição dos sintomas e o desenvolvimento de habilidades para o enfrentamento da doença crônica. No decorrer do processo, ao longo dos cinco anos de atendimento, a paciente adaptou-se positivamente à doença, ocorrendo a remissão dos sintomas de ansiedade e o desenvolvimento de comportamentos resilientes que indicaram a alta terapêutica