3,132 research outputs found
Open ocean tide modelling
Two trends evident in global tidal modelling since the first GEOP conference in 1972 are described. The first centers on the incorporation of terms for ocean loading and gravitational self attraction into Laplace's tidal equations. The second centers on a better understanding of the problem of near resonant modelling and the need for realistic maps of tidal elevation for use by geodesists and geophysicists. Although new models still show significant differences, especially in the South Atlantic, there are significant similarities in many of the world's oceans. This allows suggestions to be made for future locations for bottom pressure gauge measurements. Where available, estimates of M2 tidal dissipation from the new models are significantly lower than estimates from previous models
Alien Registration- Parke, Alice M. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/21183/thumbnail.jp
Exact vortex nucleation and cooperative vortex tunneling in dilute BECs
With the imminent advent of mesoscopic rotating BECs in the lowest Landau
level (LLL) regime, we explore LLL vortex nucleation. An exact many-body
analysis is presented in a weakly elliptical trap for up to 400 particles.
Striking non-mean field features are exposed at filling factors >>1 . Eg near
the critical rotation frequency pairs of energy levels approach each other with
exponential accuracy. A physical interpretation is provided by requantising a
mean field theory, where 1/N plays the role of Planck's constant, revealing two
vortices cooperatively tunneling between classically degenerate energy minima.
The tunnel splitting variation is described in terms of frequency, particle
number and ellipticity.Comment: 4 pages,4 figure
Identification of Transnational Threats
In the past, the starting point for threat identification was the nation state. Today, national boundaries have lost much of their significance and global forces lacking identifiable national frontiers represent a real threat to US security.
New technologies have facilitated the development of advanced terrorist methodologies and tactics.
A new and increasingly significant threat is hostile forces which operate within the borders of states which are friendly to the United States.
American universities are increasingly vulnerable to new transnational threats by virtue of the opportunities they present for acquisition of dual use technological skills.
With its new cellular structure, terrorism has been privatized, is more difficult to counter, and enjoys great access to funds, weapons, and training.
The broad anti-war coalition has created threats to the US critical infrastructure in connection with “direct action” against the Iraqi war.
In one year alone, computer criminals funneled over 2.6 billion dollars out of Russia through Cyprus.
Traffic in false documents constitutes an especially significant threat to our critical infrastructure and has become more serious with technological advances that have eased the production of such documents.
The rise of identity theft, an important variation of traffic in false documents, threatens to undermine an important infrastructure base
Scaling ansatz, four zero Yukawa textures and large
We investigate 'Scaling ansatz' in the neutrino sector within the framework
of type I seesaw mechanism with diagonal charged lepton and right handed
Majorana neutrino mass matrices (). We also assume four zero texture of
Dirac neutrino mass matrices () which severely constrain the
phenomenological outcomes of such scheme. Scaling ansatz and the present
neutrino data allow only Six such matrices out of 126 four zero Yukawa
matrices. In this scheme, in order to generate large we break
scaling ansatz in through a perturbation parameter and we also show our
breaking scheme is radiatively stable. We further investigate CP violation and
baryogenesis via leptogenesis in those surviving textures.Comment: 25 pages, 8 figures, Accepted for publication in Phys. Rev.
Glass Stiffness Contribution of Flat and Curved Cable-net Supported Glass Façade Systems
Glass used in building facade presents an aesthetic feature as well as contributes to the structural stiffness of the whole structural system of the building. In this research, the contribution of glass on the stiffness of the cable-net supported glass facade systems was investigated via experiments. Two generic configurations of cable-net system were considered, namely flat and curved cable-net system, both with and without glass panes. Each system was subjected to static load. The results indicated that the introduction of certain level of curvature to the cable net structure has increased the stiffness of the cable net structure by 11.5%. The glass panes made significant contributions to the stiffness of the whole structural system. The glass stiffness contribution for flat cable-net system was high at the early stage of loading (approximately 40%) but reduced when the load was increased. However, the glass stiffness contribution for curved cable-net increased gradually as the load was increased. For both configurations, the glass stiffness contribution remained steady at about 18% of the whole structural stiffness as the cables in the cable-net stiffened up to the maximum load.. Based on the static tests carried out, the pre-stress force in the cables in the cable-net systems can possibly be reduced should the glass be considered in the analysis design of cable-net structure. Moreover, the curved cable-net could be designed to have lower pre-stress force in cables compared to that of flat cable-net to meet the deflection criterion of the cable-net structure
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