A Zero-Temperature Study of Vortex Mobility in Two-Dimensional Vortex Glass Models

Three different vortex glass models are studied by examining the energy barrier against vortex motion across the system. In the two-dimensional gauge glass this energy barrier is found to increase logarithmically with system size which is interpreted as evidence for a low-temperature phase with zero resistivity. Associated with the large energy barriers is a breaking of ergodicity which explains why the well established results from equilibrium studies could fail. The behavior of the more realistic random pinning model is however different with decreasing energy barriers a no finite critical temperature

Failure to detect mismatches between intention and outcome in a simple decision task

A fundamental assumption of theories of decision-making is that we detect mismatches between intention and outcome, adjust our behavior in the face of error, and adapt to changing circumstances. Is this always the case? We investigated the relation between intention, choice, and introspection. Participants made choices between presented face pairs on the basis of attractiveness, while we covertly manipulated the relationship between choice and outcome that they experienced. Participants failed to notice conspicuous mismatches between their intended choice and the outcome they were presented with, while nevertheless offering introspectively derived reasons for why they chose the way they did. We call this effect choice blindness

Cryogenic CO2 condensation and membrane separation of syngas for large-scale LH2 production.

acceptedVersio

Splitting of the superconducting transition in the two weakly coupled 2D XY models

The frequency $\omega$ and temperature T dependent complex conductivity $\sigma$ of two weakly coupled 2D XY models subject to the RSJ dynamics is studied through computer simulations. A double dissipation-peak structure in $Re[\omega\sigma]$ is found as a function of T for a fixed frequency. The characteristics of this double-peak structure, as well as its frequency dependence, is investigated with respect to the difference in the critical temperatures of the two XY models, originating from their different coupling strengths. The similarity with the experimental data in Festin {\it et al.} [Physica C 369, 295 (2002)] for a thin YBCO film is pointed out and some possible implications are suggested.Comment: 4 pages, 4 figure

Hydrogen re-liquefaction Process for Boil-off Gas Handling on a Large-scale Liquid Hydrogen Carrier

With the recent focus on hydrogen, seaborne shipping is considered an option for the large-scale transport of liquid hydrogen (LH2). For efficient shipping, boil-off gas (BOG) from the cargo tanks needs to be optimally utilized. This work suggests a BOG handling system (BHS) producing fuel for an LH2 carrier and liquefying excess BOG in a hydrogen Claude cycle. The process offers a simple configuration that does not require a refrigerant makeup facility. The simulation results of the BHS also show relatively low specific power consumption (5.7 to 2.6 kWh/kgLH2) with a good utilisation of cold energy in BOG. The sensitivity analysis with the BOG to fuel (BtF) ratio shows that a higher BtF gives a simpler configuration and a smaller size liquefier, saving capital costs. However, the optimal capacity of the BHS needs to be determined based on the techno-economic performance of the entire system of the LH2 carrier. Keywords: Hydrogen, Liquefaction, Liquid hydrogen carrier, Transport, Boil-off gas, Claude cycleacceptedVersio

Ubiquitous finite-size scaling features in IV characteristics of various dynamic XY models in two dimensions

Two-dimensional (2D) XY model subject to three different types of dynamics, namely Monte Carlo, resistivity shunted junction (RSJ), and relaxational dynamics, is numerically simulated. From the comparisons of the current-voltage (I-V) characteristics, it is found that up to some constants I-V curves at a given temperature are identical to each other in a broad range of external currents. Simulations of the Villain model and the modified 2D XY model allowing stronger thermal vortex fluctuations are also performed with RSJ type of dynamics. The finite-size scaling suggested in Medvedyeva et al. [Phys. Rev. B 62, 14531(2000)] is confirmed for all dynamic models used, implying that this finite-size scaling behaviors in the vicinity of the Kosterlitz-Thouless transition are quite robust.Comment: 7 pages, 4 pictures, accepted in Physica