23,692 research outputs found
Quasiparticle Interactions in Two and Three Dimensional Superconductors
I investigate the difference between the quasiparticle properties in two
dimensional(2D)and three dimensional(3D) s-wave superconductors. Using the
original BCS model for the pairing interaction and direct Coulomb interaction I
show that quasiparticle interactions lead to a stronger energy dependence in
the single-particle self-energies in 2D than in 3D superconductors. This
difference arises from the presence of the low lying collective mode of the
order parameter in the 2D case which ensures that oscillator strength in the
response function is at low frequencies, . This strong
quantitative difference between 2D and 3D superconductors points to the
importance of treating quasiparticle interactions in low dimensional
superconductors rather than assuming that renormalizations remain unchanged
from the normal state.Comment: version of original paper accepted for publication in Europhysics
Letter
Quality management in construction projects
[Quality Management in Construction Projects by Abdul Razzak Rumane, CRC Press, Boca Raton, FL, 2011, 434 pp, ISBN 9781439838716] Issues of quality management, quality control and performance against specification have long been the focus of various business sectors. Recently there has been an additional drive to achieve the continuous improvement and customer satisfaction promised by the 20th-century ‘gurus’ some six or seven decades ago. The engineering and construction industries have generally taken somewhat longer than their counterparts in the manufacturing, service and production sectors to achieve these espoused levels of quality. The construction and engineering sectors stand to realize major rewards from better managing quality in projects. More effort is being put into instructing future participants in the industry as well as assisting existing professionals. This book comes at an opportune time
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