1/N expansion formalism for high-spin states

The 1/$N$ expansion solutions for the interacting boson model are extended to higher orders using computer algebra. The analytic results are compared with those obtained from an exact diagonalization of the Hamiltonian and are shown to be very accurate. The extended formulas for level energies and E2 transitions will be useful in the analysis of high-spin states in both normal and superdeformed nuclei.Comment: 11 pages, Latex, 3 figures available upon reques

High-spin states in boson models with applications to actinide nuclei

We use the 1/$N$ expansion formalism in a systematic study of high-spin states in the $sd$ and $sdg$ boson models with emphasis on spin dependence of moment of inertia and E2 transitions. The results are applied to the high-spin states in the actinide nuclei $^{232}$Th, $^{234-238}$U, where the need for $g$ bosons is especially acute but until now, no realistic calculation existed. We find that the $d$-boson energy plays a crucial role in description of the high-spin data.Comment: 11 pages Latex, 4 figures available upon request (to appear in Phys. Lett. B

Tests and applications of self-consistent cranking in the interacting boson model

The self-consistent cranking method is tested by comparing the cranking calculations in the interacting boson model with the exact results obtained from the SU(3) and O(6) dynamical symmetries and from numerical diagonalization. The method is used to study the spin dependence of shape variables in the $sd$ and $sdg$ boson models. When realistic sets of parameters are used, both models lead to similar results: axial shape is retained with increasing cranking frequency while fluctuations in the shape variable $\gamma$ are slightly reduced.Comment: 9 pages, 3 ps figures, Revte

Consistent description of magnetic dipole properties in transitional nuclei

It is shown that a consistent description of magnetic dipole properties in transitional nuclei can be obtained in the interacting boson model-2 by F-spin breaking mechanism, which is associated with differences between the proton and neutron deformations. In particular, the long standing anomalies observed in the $g$-factors of the Os-Pt isotopes are resolved by a proper inclusion of F-spin breaking.Comment: Revtex, 10 pages, 4 figures (available from authors upon request

Description of Nuclear Structure Effects in Subbarrier Fusion by the Interacting Boson Model

Recent theoretical developments in using the Interacting Boson Model to describe nuclear structure effects in fusion reactions below the Coulomb barrier are reviewed. Methods dealing with linear and all orders coupling between the nuclear excitations and the translational motion are discussed, and the latter is found to lead to a better description of the barrier distribution data. A systematic study of the available data (cross sections, barrier and spin distributions) in rare-earth nuclei is presented.Comment: 9 pages + 2 Figures (in eps form). To be published in the Proceedings of the FUSION97 Conference, South Durras, Australia, March 1997 (J. Phys. G). Full text and figures are also available at http://nucth.physics.wisc.edu/preprints/mad-nt-97-01.abs.htm

Anharmonic phonon excitations in subbarrier fusion reactions

Recently measured high precision data of fusion excitation function have enabled a detailed study on the effects of nuclear collective excitations on fusion reactions. Using such highly accurate data of the $^{16}$O + $^{144,148}$Sm reactions, we discuss the anharmonic properties of collective phonon excitations in $^{144,148}$Sm nuclei. It is shown that subbarrier fusion reactions are strongly affected by the anharmonic effects and thus offer an alternative method to extract the static quadrupole moments of phonon states in a spherical nucleus.Comment: 10 pages, To be published in the Proceedings of the Tours Symposium on Nuclear Physics III, Tours, France, September 1997 (American Institute of Physics

Description of superdeformed nuclei in the interacting boson model

The interacting boson model is extended to describe the spectroscopy of superdeformed bands. Microscopic structure of the model in the second minimum is discussed and superdeformed bosons are introduced as the new building blocks. Solutions of a quadrupole Hamiltonian are implemented through the $1/N$ expansion method. Effects of the quadrupole parameters on dynamic moment of inertia and electric quadrupole transition rates are discussed and the results are used in a description of superdeformed bands in the Hg-Pb and Gd-Dy regions.Comment: 18 pages revtex, 9 figures available upon reques

Value chain analysis: A general framework for airlines

Havayolu işletmeleri faaliyet gösterdikleri karmaşık ve rekabetçi çevrede varlıklarını ve karlılıklarını sürdürmek için bu çevreyi iyi anlamalı ve analiz etmelidirler. Ayrıca, havayolu işletmelerinin iç çevreleri de oldukça karmaşık bir yapıdadır. Tüm havayolu faaliyetlerinin emniyeti sağlayacak şekilde eşgüdüm içerisinde, istenen kalitede ve en az maliyetle yerine getirilmesi gerekmektedir. Değer zinciri analizi, bu bakımdan havayolu işletmelerine bakış açısı sağlayan bir araçtır. Bu çalışmada öncelikle, genel olarak değer zinciri analizi ele alınmış ve ardından havayolu işletmeleri için endüstri ve işletme seviyesinde değer zinciri analizi çerçevesi oluşturulmuştur. Buna ek olarak, havayolu işletmeleri için değer zinciri analizinin yararları üzerinde durulmuştur. Havayolu işletmelerine bu çerçeveden bakıldığında, her havayolu işletmesinin rekabetçi durumunu keskinleştirmek için değer zincirini anlaması ve değer zinciri içerisindeki bağlantıları iyi bir şekilde yönetmesi gereği ortaya çıkmaktadır.Airlines are operating in a complex and competitive environment. Therefore, they should understand and analyze the environment to maintain their existence and profitability. Business structure of airlines is also quite complex. Airline activities should be carried out in a coordination ensuring safety at a minimum cost and a desired quality. Considered to these, value chain analysis is a tool that provides a perspective to the airline business. In this study, firstly, value chain analysis has been introduced, and then, value chain analysis framework was developed for the airline industry and airlines. In addition, benefits of value chain analysis are mentioned for airline business. From this framework, it is suggested that each airline should understand the value chain and manage the links within the value chain to sharpen their competitiveness