PeerPigeon: A Web Application to Support Generalised Peer Review

Peer Review (also known as Peer Assessment) is an important technique in learning, but can be difficult to support through e-learning due to the complexity and variety of peer review processes. In this paper we present PeerPigeon, a Web 2.0 style application that supports generalised Peer Review by using a canonical model of Peer Review based on a Peer Review Pattern consisting of Peer Review Cycles, each defined in terms of Peer Review Transforms. We also demonstrate how PeerPigeon makes use of a Domain Specific Language based on Ruby to define these plans, and thus cope with the irreducible complexity of the flow of documents around a peer network

A New Framework for Network Disruption

Traditional network disruption approaches focus on disconnecting or lengthening paths in the network. We present a new framework for network disruption that attempts to reroute flow through critical vertices via vertex deletion, under the assumption that this will render those vertices vulnerable to future attacks. We define the load on a critical vertex to be the number of paths in the network that must flow through the vertex. We present graph-theoretic and computational techniques to maximize this load, firstly by removing either a single vertex from the network, secondly by removing a subset of vertices.Comment: Submitted for peer review on September 13, 201

Parameterization of travelling waves in plane Poiseuille flow

© The authors 2012. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved. This is a pre-copyedited, author-produced PDF of an article accepted for publication in [IMA Journal of Applied Mathematics ] following peer review. The version of record [ IMA Journal of Applied Mathematics (2014) 79(1): 22-32.] is available online at: http://imamat.oxfordjournals.org/content/79/1/22The first finite-dimensional parameterization of a subset of the phase space of the Navier-Stokes equations is presented. Travelling waves in two-dimensional plane Poiseuille flow are numerically shown to approximate maximum-entropy configurations. In a coordinate system moving with the phase velocity, the enclosed body of the flow exhibits a hyperbolic sinusoidal relationship between the vorticity and stream function. The phase velocity and two-amplitude parameters describe the stable manifold on the slow viscous time scale. This original parameterization provides a valuable visualization of this subset of the phase space of the Navier-Stokes equations. These new results provide physical insight into an important intermediate stage in the instability process of plane Poiseuille flow

Experimental study on a metal hydride based hydrogen compressor

This is the post-print version of the final paper published in Journal of Alloys and Compounds. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2008 Elsevier B.V.A three-stage metal hydride based hydrogen compressor prototype was built. It has been designed for a hydrogen production facility using a low-pressure alkaline electrolyser. The compression system should transfer heat recovered from the electrolyser into the hydride beds to allow hydrogen desorption flow. The three-stage compressor achieves a compression ratio of 20:1 atm. It performs a thermal cycling of three AB5 hydrides between 20 and 80 °C. Its flow rate, for 25 g of each hydride bed, reaches about 20 l (NTP) of hydrogen per hour. The prototype is now operational. Some improvements in the heat transfer management system are also carried out before proceeding to the interconnection with the electrolyser and to the extent that the hydrogen produced satisfies the high purity requirement of the hydrides used in the compressor.Natural Resources Canada(NRCan), Ministère des Ressources Naturelles et de la Faune du Québec (MRNF), and Natural Sciences and Engineering Research Council of Canada

Flow states in exercise: A systematic review

Objectives: The purpose of this study was to systematically identify, review, synthesise, and appraise current literature on flow in exercise. By doing so, this study aimed to highlight gaps and future research directions that will help to advance understanding and application of flow states in this setting. Design: A systematic review using PRISMA guidelines. Methods: Eight electronic databases were searched in February 2019. Inclusion criteria were peer-reviewed studies focused on the investigation of flow in exercise. Exclusion criteria were studies that did not exclusively include exercise participants, or that focused on instrument development and/or validation. Data from included studies were extracted and reported in a narrative synthesis. Results: A total of 26 studies that were conducted with 4478 participants met the inclusion criteria. Several issues with the conceptualisation and measurement of flow in exercise were identified, which makes it difficult to draw meaningful conclusions about this literature. Nevertheless, there is tentative evidence that exergame design features, music, and virtual stimuli can affect at least some dimensions of flow. While little attention has been directed towards developing an explanatory theory, initial findings concerning the contexts and process underlying flow occurrence could offer a potential avenue for progress. Conclusions: The review advances knowledge by synthesising quantitative and qualitative evidence on flow states in exercise. By doing so, the review also highlights a range of conceptual and methodological issues in the field. Recommendations to address these issues and suggestions for making meaningful progress to develop understanding of flow states in exercise are advanced

Global magnetohydrodynamical models of turbulence in protoplanetary disks I. A cylindrical potential on a Cartesian grid and transport of solids

We present global 3D MHD simulations of disks of gas and solids, aiming at developing models that can be used to study various scenarios of planet formation and planet-disk interaction in turbulent accretion disks. A second goal is to show that Cartesian codes are comparable to cylindrical and spherical ones in handling the magnetohydrodynamics of the disk simulations, as the disk-in-a-box models presented here develop and sustain MHD turbulence. We investigate the dependence of the magnetorotational instability on disk scale height, finding evidence that the turbulence generated by the magnetorotational instability grows with thermal pressure. The turbulent stresses depend on the thermal pressure obeying a power law of 0.24+/-0.03, compatible with the value of 0.25 found in shearing box calculations. The ratio of stresses decreased with increasing temperature. We also study the dynamics of boulders in the hydromagnetic turbulence. The vertical turbulent diffusion of the embedded boulders is comparable to the turbulent viscosity of the flow. Significant overdensities arise in the solid component as boulders concentrate in high pressure regions.Comment: Changes after peer review proces

Squirt flow in partially saturated cracks: a simple analytical model

This is a pre-copyedited, author-produced PDF of an article published in Geophysical Journal International following peer review. The version of record ``Santiago G Solazzi, Simón Lissa, J Germán Rubino, Klaus Holliger, Squirt flow in partially saturated cracks: a simple analytical model, Geophysical Journal International, Volume 227, Issue 1, October 2021, Pages 680–692’ is available online at: https://doi.org/10.1093/gji/ggab249

Voltage security evaluation based on perturbation method

This is the post-print version of the final paper published in International Journal of Electrical Power & Energy Systems. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2009 Elsevier B.V.This paper proposes a new algorithm for estimating voltage security margin. The algorithm is based on the perturbation method and has significant computational efficiency. The proposed algorithm can be used for on-line voltage security evaluation. It has been validated using IEEE-14, IEEE-30 and IEEE-57 bus systems. Results from the tests show higher efficiency and smaller error margins compared to continuation power flow (CPF) method. Voltage collapse is a serious threat to the security of stressed power systems; therefore, voltage security (VS) has become a major challenge for management of power systems. The motivation for this research is a direct consequence of the deregulation of electricity industries and markets worldwide

Vortex crystals

Vortex crystals is one name in use for the subject of vortex patterns that move without change of shape or size. Most of what is known pertains to the case of arrays of parallel line vortices moving so as to produce an essentially two-dimensional flow. The possible patterns of points indicating the intersections of these vortices with a plane perpendicular to them have been studied for almost 150 years. Analog experiments have been devised, and experiments with vortices in a variety of fluids have been performed. Some of the states observed are understood analytically. Others have been found computationally to high precision. Our degree of understanding of these patterns varies considerably. Surprising connections to the zeros of 'special functions' arising in classical mathematical physics have been revealed. Vortex motion on two-dimensional manifolds, such as the sphere, the cylinder (periodic strip) and torus (periodic parallelogram) has also been studied, because of the potential applications, and some results are available regarding the problem of vortex crystals in such geometries. Although a large amount of material is available for review, some results are reported here for the first time. The subject seems pregnant with possibilities for further development.published or submitted for publicationis peer reviewe