7,434 research outputs found
On the Sutherland's Integrability Condition for Two-Dimensional N-Particle Systems
Following Sutherland's work on one-dimensional integrable systems we
formulate and study its two-dimensional version. Physically it expresses the
absence of true 3-body forces among an assembly of N particles leaving
exclusively effective 2-body interactions. This criterion may be a suitable
candidate for an integrability condition.Comment: 13 pages,uses LATeX2e and epsf. File prepared using the uufiles
packag
Lamb shift of non-degenerate energy level systems placed between two infinite parallel conducting plates
The issue of the observability of the Lamb shift in systems with
non-degenerate energy levels is put to question. To this end, we compute the
Lamb shift of such systems in the electromagnetic environment provided by two
infinite parallel conducting plates, which is instrumental in demonstrating the
existence of the so-called Casimir effect. A formula giving the relative change
in the Lamb shift (as compared to the standard one in vacuum) is explicitly
obtained for spherical semiconductor Quantum Dots (QD). It is the result of a
careful mathematical treatment of divergences in the calculations involving
distribution theory, which also settles a controversy on two different
expressions in the existing literature. It suggests a possibility of QD
non-degenerate energy spectrum fine-tuning for experimental purposes as well as
a Gedankenexperiment to observe the Lamb shift in spherical semiconductor
quantum dots.Comment: submit/040994
Quantum properties of spherical semiconductor quantum dots
Quantum effects at the nanometric level have been observed in many confined
structures, and particularly in semiconductor quantum dots (QDs). In this work,
we propose a theoretical improvement of the so-called effective mass
approximation with the introduction of an effective pseudo-potential. This
advantageously allows analytic calculations to a large extent, and leads to a
better agreement with experimental data. We have obtained, as a function of the
QD radius, in precise domains of validity, the QD ground state energy, its
Stark and Lamb shifts. An observable Lamb shift is notably predicted for
judiciously chosen semiconductor and radius. Despite the intrinsic
non-degeneracy of the QD energy spectrum, we propose a Gedankenexperiment based
on the use of the Casimir effect to test its observability. Finally, the effect
of an electromagnetic cavity on semiconductor QDs is also considered, and its
Purcell factor evaluated. This last result raises the possibility of having a
QD-LASER emitting in the range of visible light
Human trafficking and organised crime
international economy;illegal immigration;international migration;organized crime
Human Security and the Governmentality of Neo-Liberal Mobility: A Feminist Perspective
Transnational migration and its implications for human security as a policy field constitute one of the most complex issues of our time. Current experiences of displacement and security spans between a cyber world characterized by hyper mobility of finance, technology, information and the ââŹËcosmopolitanââŹâ˘ values of a ââŹËflexible citizenshipââŹâ˘ (Ong, 1999) to the world of human trafficking and smuggling of migrants and refugees as a mode of mobility adopted by people who cross borders on foot, by boat, trucks and planes who are often abandoned to die when arrangements break down (Eschbach/Hagan/Rodriguez, 2001; El-Cherkeh/Hella, 2004). The extant legal vacuum reflects unresolved conflicts of interest at different levels and poses a great challenge to the right to mobility as an expression of the liberal ideal of individual liberty.feminist perspective;human security;neo-liberal mobility
Liberalisation, care and the struggle for women's social citizenship in Vietnam
social policy;subsidies;Viet Nam;economic liberalization;care work;women workers;women's rights
Gender and enterprise development in Vietnam under Doi-Moi : issues for policy, research and training
Viet Nam;economic development;gender equality;small enterprises;women entrepreneurs
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