550 research outputs found
Editorial
The last year has been a very busy one for the BMB. We have published 140 articles online, which is over twice the publication rate of the previous year. This reflects the increase in the submission rates and Springer's view that papers should be published online as quickly as possible. In addition, the entire archive of the Bulletin of Mathematical Biology is now available on the Springer website for the journal, digitized back to Vol. 1, No. 1, published in 1939
Noise generation from interacting high speed axisymmetric jet flows Semiannual status report, 1 Jun. 1968 - 31 Dec. 1969
Far field noise generation from interacting coaxial jet flows, and nozzle operational mode
Scanning tunneling spectroscopy of superconducting LiFeAs single crystals: Evidence for two nodeless energy gaps and coupling to a bosonic mode
The superconducting compound, LiFeAs, is studied by scanning tunneling
microscopy and spectroscopy. A gap map of the unreconstructed surface indicates
a high degree of homogeneity in this system. Spectra at 2 K show two nodeless
superconducting gaps with meV and
meV. The gaps close as the temperature is increased to the bulk
indicating that the surface accurately represents the bulk. A dip-hump
structure is observed below with an energy scale consistent with a
magnetic resonance recently reported by inelastic neutron scattering
Magnetic phase diagram of
Magnetometry, electrical transport, and neutron scattering measurements were
performed on single crystals of the Fe^{4+}-containing perovskite-related phase
Sr_3Fe_2O_7-x as a function of oxygen content. Although both the crystal
structure and electron configuration of this compound are closely similar to
those of well-studied ruthenates and manganates, it exhibits very different
physical properties. The fully-oxygenated compound (x=0) exhibits a
charge-disproportionation transition at T_D = 340 K, and an antiferromagnetic
transition at T_N = 115 K. For temperatures T \leq T_D, the material is a
small-gap insulator; the antiferromagnetic order is incommensurate, which
implies competing exchange interactions between the Fe^{4+} moments. The
fully-deoxygenated compound (x=1) is highly insulating, and its Fe^{3+} moments
exhibit commensurate antiferromagnetic order below T_N ~ 600 K. Compounds with
intermediate x exhibit different order with lower T_N, likely as a consequence
of frustrated exchange interactions between Fe^{3+} and Fe^{4+} sublattices. A
previous proposal that the magnetic transition temperature reaches zero is not
supported.Comment: 8 pages, 6 figure
Beam Optics Study for a Potential VHEE Beam Delivery System
VHEE (Very High Energy Electron) therapy can be superior to conventional radiotherapy for the treatment of deep seated tumours, whilst not necessarily requiring the space and cost of proton or heavy ion facilities. Developments in high gradient RF technology have allowed electrons to be accelerated to VHEE energies in a compact space, meaning that treatment could be possible with a shorter linac. A crucial component of VHEE treatment is the transfer of the beam from accelerator to patient. This is required to magnify the beam to cover the transverse extent of the tumour, whilst ensuring a uniform beam distribution. Two principle methodologies for the design of a compact transfer line are presented. The first of these is based upon a quadrupole lattice and optical magnification of beam size. A minimisation algorithm is used to enforce certain criteria on the beam distribution at the patient, defining the lattice through an automated routine. Separately, a dual scattering-foil based system is also presented, which uses similar algorithms for the optimisation of the foil geometry in order to achieve the desired beam shape at the patient location
The Doha Declaration and Beyond: Giving a Voice to Non-Trade Concerns Within the WTO Trade Regime
The World Trade Organization (WTO) has been a significant force in the liberalization of trade across international borders since its inception in 1995. Commentators suggest that its reforms have converted the focus of international trade policy from removal of barriers to positive policy-making--a field historically occupied by domestic authorities. And although largely successful in the promotion of international trade, the Authors suggest that the binding provisions of the WTO ignore non-trade concerns such as environmental protection, consumer rights, labor rights, and state sovereignty. The Agreement\u27s inattention to these related concerns is the primary locus of criticism of the WTO, culminating in the breakdown of the 1999 Ministerial Meeting in Seattle, Washington. The Article examines the relationship between the Agreement and environmental, consumer protection, and labor policy, as well as the implications of WTO membership on state sovereignty. The Authors conclude that to improve the WTO\u27s treatment of non-trade concerns, the WTO must increase participation to include non-trade stakeholders, develop and support expertise within the WTO to address non-trade concerns, and follow the blueprint articulated in the Ministerial Declaration at the Fourth Ministerial Conference in Doha. The Declaration recognizes the importance of non-trade concerns and suggests a course of action that is likely to require the WTO to more squarely address the relationship between trade and non-trade policy
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