31,135 research outputs found
On the exploitability of thermo-charged capacitors
Recently [Physics Letters A, 374, (2010) 1801] the concept of vacuum
capacitor spontaneously charged harnessing the heat from a single thermal
reservoir at room temperature has been introduced, along with a mathematical
description of its functioning and a discussion on the main paradoxical feature
that seems to violate the Second Law of Thermodynamics. In the present paper we
investigate the theoretical and practical possibility of exploiting a such
thermo-charged capacitor as voltage/current generator: we show that if very
weak provisos on the physical characteristics of the capacitor are fulfilled,
then a non-zero current should flow across the device, allowing the generation
of potentially usable voltage, current and electric power out of a single
thermal source at room temperature. Preliminary results show that the power
output is tiny but non-zero.Comment: 23 Pages, 10 Figures. Physica A 390/6 (2011) 482 + Addendum (2013
GMRES for oscillatory matrix-valued differential equations
We investigate the use of Krylov subspace methods to solve linear, oscillatory ODEs. When we apply a Krylov subspace method to a properly formulated equation, we retain the asymptotic accuracy of the asymptotic expansion whilst converging to the exact solution. We will demonstrate the effectiveness of this method by computing Error and Mathieu functions
A Note on Solid-State Maxwell Demon
Starting from 2002, at least two kinds of laboratory-testable, solid-state
Maxwell demons have been proposed that utilize the electric field energy of an
open-gap n-p junction and that seem to challenge the validity of the Second Law
of Thermodynamics. In the present paper we present some arguments against the
alleged functioning of such devices.Comment: 9 pages, 4 figures. Foundations of Physics, forthcoming. arXiv admin
note: substantial text overlap with arXiv:1101.505
Writing and the zeitgeist
Have contemporary writers anything to say about their times and, if so, have they the nerve to say it? This article argues that there is much failure of vision and failure of nerve on the part of today's writers. Because they lack the clarity and courage to come to terms with the times, they succumb to its deceptions and seductions. Its thesis is is that the power and value of writing is in the scope and depth of its engagement with the zeitgeist; in how perceptively a writer captures the spirit of the age, expresses the temper of the times; in how much of what is there in the air, throbbing in the collective psyche, pulsing in the ever shifting social order, a writer gathers up and expresses in accurate and resonant images, in provocative and paradigmatic stories. This is pursued in reflection on attitudes expressed at two international writers conferences and in polemic against the prevailing views expressed
Has the red flag fallen?
This pamphlet asked the question: has socialism come to the end of the line or can it find a new path forward
To the Crucible: An Irish engagement with the Greek crisis and the Greek left
A monumental drama is playing out before our eyes. It is a true Greek tragedy. The plot: A society is being pushed to its limits. The denouement is not yet determined, but survival is at stake and prospects are precarious. Greece is at the sharp end of a radical and risky experiment in how far accumulation by dispossession can go, how much expropriation can be endured, how far the state can be subordinated to the market. It is a global narrative, but the story is a few episodes ahead here. Greece is the crucible. It is a caldron where concentrated forces are colliding in a process that will bring forth either a reconfiguration of capitalism or the dawn of its demise
Computing the Hilbert transform and its inverse
We construct a new method for approximating Hilbert transforms and their inverse throughout the complex plane. Both problems can be formulated as Riemann-Hilbert problems via Plemelj's lemma. Using this framework, we re-derive existing approaches for computing Hilbert transforms over the real line and unit interval, with the added benefit that we can compute the Hilbert transform in the complex plane. We then demonstrate the power of this approach by generalizing to the half line. Combining two half lines, we can compute the Hilbert transform of a more general class of functions on the real line than is possible with existing methods
Philosophers, scientists and the unity of science
This paper examines historical images of the unity of science and makes a case for a contemporary conceptualisation of this project for our own times. It argues that, to overcome the fragmentation of knowledge, it is necessary to have an adequate and appropriate philosophy. This paper outlines the parameters of such a philosophy
Soap opera and social order: Glenroe, Fair City and contemporary Ireland.
How far can contemporary Ireland recognise itself in Glenroe and Fair City? To what extent do its characters, settings and storylines testify to the temper of the times? What relation do these serials bear to the lives we lead?
This paper will look at Ireland's two running television serials in terms of the larger pattern of social experience. It will query both the presences and the absences in their representation of contemporary Ireland. It will explore the soap opera form in terms of its potential for imagining Ireland in a more expansive and penetrating fashion. It will draw strong conclusions about the failure of existing serials to fulfill this potential
J D Bernal: philosophy, politics and the science of science
This paper is an examination of the philosophical and political legacy of John Desmond Bernal. It addresses the evidence of an emerging consensus on Bernal based on the recent biography of Bernal by Andrew Brown and the reviews it has received. It takes issue with this view of Bernal, which tends to be admiring of his scientific contribution, bemused by his sexuality, condescending to his philosophy and hostile to his politics. This article is a critical defence of his philosophical and political position
- …