Pacific Island countries: in search of a trade strategy

International trade is vital for economic prosperity in Pacific island countries, but their trade performance has been weak over the past decade with the exception of resource-rich countries. Small country size and remoteness from global economic centers may have contributed to this relatively poor performance. However, the emergence of Asia as a global economic center presents Pacific island countries with an unprecedented opportunity to develop trade with Asia, particularly in tourism for a number of PICs. Moreover, if a strong two-way linkage is established between tourism and agriculture,Pacific island countries stands a better chance to improve broad-based growth

Structural modelling and testing of failed high energy pipe runs: 2D and 3D pipe whip

Copyright @ 2011 ElsevierThe sudden rupture of a high energy piping system is a safety-related issue and has been the subject of extensive study and discussed in several industrial reports (e.g. [2], [3] and [4]). The dynamic plastic response of the deforming pipe segment under the blow-down force of the escaping liquid is termed pipe whip. Because of the potential damage that such an event could cause, various geometric and kinematic features of this phenomenon have been modelled from the point of view of dynamic structural plasticity. After a comprehensive summary of the behaviour of in-plane deformation of pipe runs [9] and [10] that deform in 2D in a plane, the more complicated case of 3D out-of-plane deformation is discussed. Both experimental studies and modelling using analytical and FE methods have been carried out and they show that, for a good estimate of the “hazard zone” when unconstrained pipe whip motion could occur, a large displacement analysis is essential. The classical, rigid plastic, small deflection analysis (e.g. see [2] and [8]), is valid for estimating the initial failure mechanisms, however it is insufficient for describing the details and consequences of large deflection behaviour

Coarse-Grained Online Monitoring of BTI Aging by Reusing Power-Gating Infrastructure

In this paper, we present a novel coarse-grained technique for monitoring online the bias temperature instability (BTI) aging of circuits by exploiting their power gating infrastructure. The proposed technique relies on monitoring the discharge time of the virtual-power-network during standby operations, the value of which depends on the threshold voltage of the CMOS devices in a power-gated design (PGD). It does not require any distributed sensors, because the virtual-power-network is already distributed in a PGD. It consists of a hardware block for measuring the discharge time concurrently with normal standby operations and a processing block for estimating the BTI aging status of the PGD according to collected measurements. Through SPICE simulation, we demonstrate that the BTI aging estimation error of the proposed technique is less than 1% and 6.2% for PGDs with static operating frequency and dynamic voltage and frequency scaling, respectively. Its area cost is also found negligible. The power gating minimum idle time (MIT) cost induced by the energy consumed for monitoring the discharge time is evaluated on two scalar machine models using either x86 or ARM instruction sets. It is found less than 1.3× and 1.45× the original power gating MIT, respectively. We validate the proposed technique through accelerated aging experiments conducted with five actual chips that contain an ARM cortex M0 processor, manufactured with a 65 nm CMOS technology

Nondissipative Drag Conductance as a Topological Quantum Number

We show in this paper that the boundary condition averaged nondissipative drag conductance of two coupled mesoscopic rings with no tunneling, evaluated in a particular many-particle eigenstate, is a topological invariant characterized by a Chern integer. Physical implications of this observation are discussed.Comment: 4 pages, no figure. Title modified and significant revision made to the text. Final version appeared in PR

Collective edge modes in fractional quantum Hall systems

Over the past few years one of us (Murthy) in collaboration with R. Shankar has developed an extended Hamiltonian formalism capable of describing the ground state and low energy excitations in the fractional quantum Hall regime. The Hamiltonian, expressed in terms of Composite Fermion operators, incorporates all the nonperturbative features of the fractional Hall regime, so that conventional many-body approximations such as Hartree-Fock and time-dependent Hartree-Fock are applicable. We apply this formalism to develop a microscopic theory of the collective edge modes in fractional quantum Hall regime. We present the results for edge mode dispersions at principal filling factors $\nu=1/3,1/5$ and $\nu=2/5$ for systems with unreconstructed edges. The primary advantage of the method is that one works in the thermodynamic limit right from the beginning, thus avoiding the finite-size effects which ultimately limit exact diagonalization studies.Comment: 12 pages, 9 figures, See cond-mat/0303359 for related result

The ground state of the two-leg Hubbard ladder: a density--matrix renormalization group study

We present density-matrix renormalization group results for the ground state properties of two-leg Hubbard ladders. The half-filled Hubbard ladder is an insulating spin-gapped system, exhibiting a crossover from a spin-liquid to a band-insulator as a function of the interchain hopping matrix element. When the system is doped, there is a parameter range in which the spin gap remains. In this phase, the doped holes form singlet pairs and the pair-field and the "$4 k_F$" density correlations associated with pair density fluctuations decay as power laws, while the "$2 k_F$" charge density wave correlations decay exponentially. We discuss the behavior of the exponents of the pairing and density correlations within this spin gapped phase. Additional one-band Luttinger liquid phases which occur in the large interband hopping regime are also discussed.Comment: 14 pages, 18 figures, uses Revtex with epsfig to include the figure

A REAL TIME MONITORING MODEL OF THE CALCIUM CARBONATE FOULING INDUCTION PERIOD BASED ON THE CONDUCTANCE TITRATION

A new method has been developed to monitor the calcium carbonate fouling induction period (CCFIP) in real time. Based on the conductance titration, this paper investigated the forming process of CCFIP by a staticdynamic combined simulation experiment unit. With the help of titration analysis (that is titrimetry), an accurate definition of CCFIP and the corresponding real time monitoring model were built up. The investigation results show that the proposed model applies not only to measure the CCFIP in real time, but also applies to an investigation of the influence of various factors on the CCFIP

The Constraint on FCNC Coupling of the Top Quark with a Gluon from ep Collisions

Using the constraint on the single top production cross-section obtained at the HERA collider, $\sigma(ep \to e t X)$, we evaluate an upper limit on oupling constant of the anomalous top quark interaction with a gluon via flavor-changing neutral current: $|\kappa_{tgq}/\Lambda| \le 0.4 {TeV}^{-1}$, BR$(t \to gq) < 13$Comment: Latex, 3 figures, missed references were adde

Developing optofluidic technology through the fusion of microfluidics and optics

We describe devices in which optics and fluidics are used synergistically to synthesize novel functionalities. Fluidic replacement or modification leads to reconfigurable optical systems, whereas the implementation of optics through the microfluidic toolkit gives highly compact and integrated devices. We categorize optofluidics according to three broad categories of interactions: fluid-solid interfaces, purely fluidic interfaces and colloidal suspensions. We describe examples of optofluidic devices in each category. ©2006 Nature Publishing Group

3He/4He ratios of fumaroles and bubbling gases of hot springs in Tatun Volcano Group, North Taiwan

Eleven representative fumarolic gases and bubbling gases of hot springs have been collected from Tatun Volcano Group, North Taiwan for the helium isotope measurement. All the samples, except one, exhibit consistent corrected helium isotope ratios (3He/4He) with the mean value of 4.67 times of air ratios (RA). The preliminary helium data show that more than 60% of helium composition comes from deep magmatic source in this area. It implies that a relic magma reservoir may still exist underneath North Taiwan