1,915 research outputs found
Towards a unification of HRT and SCOZA. Analysis of exactly solvable mean-spherical and generalized mean-spherical models
The hierarchical reference theory (HRT) and the self-consistent
Ornstein-Zernike approximation (SCOZA) are two liquid state theories that both
furnish a largely satisfactory description of the critical region as well as
the phase coexistence and equation of state in general. Furthermore, there are
a number of similarities that suggest the possibility of a unification of both
theories. Earlier in this respect we have studied consistency between the
internal energy and free energy routes. As a next step toward this goal we here
consider consistency with the compressibility route too, but we restrict
explicit evaluations to a model whose exact solution is known showing that a
unification works in that case. The model in question is the mean spherical
model (MSM) which we here extend to a generalized MSM (GMSM). For this case, we
show that the correct solutions can be recovered from suitable boundary
conditions through either of SCOZA or HRT alone as well as by the combined
theory. Furthermore, the relation between the HRT-SCOZA equations and those of
SCOZA and HRT becomes transparent.Comment: Minimal correction of some typos found during proof reading. Accepted
for publication in Phys. Rev.
The preparation of metallic boron
Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1940.Includes bibliographical references (leaf 31).by James F. Levis.B.S
Studies on the Contact Sensitization of Man with Simple Chemicals
Dinitrochlorobenzene (DNCB) coupled to peripheral blood erythrocytes or leukocytes forms a particulate complex, DNCB-antigen. The addition of DNCB-antigen induced blastogenesis and DNA synthesis in leukocyte cultures from DNCB-sensitized human subjects and not in leukocyte cultures from nonsensitized controls. In general, sensitized subjects who displayed a higher degree of cutaneous reactivity to DNCB, as manifested by duration and intensity of dermatitis, also showed a greater blastogenic response to DNCB-antigen in vitro. This quantitative correlation, however, was not invariant. Certain soluble factor(s), or lymphokines are released following the addition of DNCB-antigen to leukocyte cultures prepared from some sensitive subjects who were rechallenged one or more times with DNCB. These lymphokines induce blastogenesis in secondary target leukocyte populations from nonsensitized subjects. Extended studies are presented which show little or no lymphokine activity in peripheral blood leukocyte cultures during a primary immune response, despite high degrees of blastogenic activity in response to DNCB-antigen. Significant lymphokine activity was observed only following additional rechallenge with DNCB.Blastogenesis and skin reactivity specific for DNCB have been shown to develop at about the same time during a primary immune response. This, along with the quantitative correlation shown in this communication, suggests that both processes probably reflect thymic-dependent cellular immunity. The appearance of lymphokine activity following rechallenge with DNCB suggests that DNCB-induced lymphokines may represent an amplifying mechanism of the cellular immune response that involves recruitment of previously uncommitted lymphocytes
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