8,518 research outputs found
Reflection and Transmission for Conformal Defects
We consider conformal defects joining two conformal field theories along a
line. We define two new quantities associated to such defects in terms of
expectation values of the stress tensors and we propose them as measures of the
reflectivity and transmissivity of the defect. Their properties are
investigated and they are computed in a number of examples. We obtain a
complete answer for all defects in the Ising model and between certain pairs of
minimal models. In the case of two conformal field theories with an enhanced
symmetry we restrict ourselves to non-trivial defects that can be obtained by a
coset construction.Comment: 32 pages + 13 pages appendix, 12 figures; v2: added eqns (2.7), (2.8)
and refs [6,7,39,40], version published in JHE
Role of nutrients in controlling stream algae levels in a developing watershed of the Northern Rockies
Phenomenological Social Science and Holistic Social Policy
The reliability of positivistic social science knowledge poses seminal problems for social policy. Needed is more sound phenomenological and qualitative research within the conspectus of the twin theoretical movements of ethnomethodology and the Frankfurt School, towards the goal of a more holistic social science knowledge base as well as a more holistic social policy
The idea of a university: Some philosophic implications for the community-junior college
Individuals and the society they live in are a great part of what the educational enterprise is all about
VALUE PROBLEMS IN THE QUEST FOR SANCTION IN SOCIAL PLANNING
At all stages in the social planning operation values play a decisive role. Dahn's six value dilemmas confronting the planner are explored, with two added: planner values are often indistinguishable from the escape from controversy and are unwilling to reveal monopol istic and repressive atmospheres and situations in society. If Mnrcuse and the Frankfurt School are correct in characterizing society as repressive, then the obligation of the planner accelerates even more to the forefront - to represent the most liberating of values. Rein's three planning strategies are traced: rational analysis {knowledge power}, citizen participation, and elite consensus, with the accompanying value difficulties of each.http://web.ku.edu/~starjrn
Psychiatric Challenge of Witnesses
Although insane\u27 persons were incompetent as witnesses at early common law, the modern view is that the effect of mental illness upon competency is a preliminary question for the court in the absence of contrary statutory direction. An insane person is generally said to be a competent witness if he can understand the sanctions imposed to elicit the truth and can correctly recount the occurrence which is the subject of his testimony. Some courts exclude evidence of insanity offered for purposes of impeachment but most courts admit such evidence, treating medical and lay testimony with equal respect because of the refusal of the earlier cases to consider insanity as exclusively within the province of experts
Theoretical studies of positronium formation in positron collisions with lithium and hydrogen atoms
The Kohn variational method has been used to study elastic scattering and positronium (Ps) formation in positron collisions with atomic hydrogen and lithium, in the energy region where only these two channels are open.
In common with other alkali metals, lithium is interesting in that its valence electron is sufficiently weakly bound that positronium formation is exothermic, and hence an open channel for incident positrons of zero energy. For such a process, Wigner's threshold theory predicts an s-wave cross section which has an inverse dependence on the wavenumber, k, of the projectile as k→0.
Using a model potential and very elaborate trial functions, a detailed investigation of s- and p-wave positron-lithium scattering has been made in the energy range 0-1.84eV, and preliminary results have also been obtained for d-wave scattering. The s-wave Ps formation cross section, as calculated variationally, appears to be in accordance with the Wigner theory, although this partial wave contributes negligibly to the Ps channel across most of the energy range considered. The p and d partial waves make a much more substantial contribution to the rearrangement process.
New cross sections for positron-hydrogen scattering have been calculated for the energy region close to the positronium formation threshold, and results have been compared with the predictions of R-matrix threshold theory
Improved Ecosystem Indicator Tools for Water QualityManagement – Genomic Analysis of Periphyton to IdentifyStressors
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