228 research outputs found
Negotiating trade-offs between the environment, sustainability and mass tourism amongst guides on Svalbard
This paper investigates how guides on Svalbard make sense of their relations to the environment
whilst working with mass tourism. The Arctic is heating up more rapidly than any other part of
the world, and over the last 30 years the effect of climate change has had a large impact on the
environment in the Arctic. The guides as such find themselves living a paradox where their
work destroys the nature that they care about and depend on. This paper analyses empirical
data collected during four months of fieldwork amongst guides in Svalbard. Throughout the
paper, two dimensions are explored: the guides’ relation to and understanding of the environment as well as their ways of caring for it. Building on illustrations of the guides’ preconceptions
of the environment, it is shown how the guides in their everyday life are engaged in pro-environmental practices. These practices are embedded in the guides’ reciprocal relationship with
the environment, where they negotiate between different trade-offs. The guides thus find a way
to navigate the complexity of caring for the environment and working in tourism through their
intimate relation to the environment
Evaluation of agents and study of end-user needs and behaviour for e-commerce. COGITO focus group experiment
The calibration of the Sudbury Neutrino Observatory using uniformly distributed radioactive sources
The production and analysis of distributed sources of 24Na and 222Rn in the
Sudbury Neutrino Observatory (SNO) are described. These unique sources provided
accurate calibrations of the response to neutrons, produced through
photodisintegration of the deuterons in the heavy water target, and to low
energy betas and gammas. The application of these sources in determining the
neutron detection efficiency and response of the 3He proportional counter
array, and the characteristics of background Cherenkov light from trace amounts
of natural radioactivity is described.Comment: 24 pages, 13 figure
Self-trapping transition for nonlinear impurities embedded in a Cayley tree
The self-trapping transition due to a single and a dimer nonlinear impurity
embedded in a Cayley tree is studied. In particular, the effect of a perfectly
nonlinear Cayley tree is considered. A sharp self-trapping transition is
observed in each case. It is also observed that the transition is much sharper
compared to the case of one-dimensional lattices. For each system, the critical
values of for the self-trapping transitions are found to obey a
power-law behavior as a function of the connectivity of the Cayley tree.Comment: 6 pages, 7 fig
Small, Dense Quark Stars from Perturbative QCD
As a model for nonideal behavior in the equation of state of QCD at high
density, we consider cold quark matter in perturbation theory. To second order
in the strong coupling constant, , the results depend sensitively on
the choice of the renormalization mass scale. Certain choices of this scale
correspond to a strongly first order chiral transition, and generate quark
stars with maximum masses and radii approximately half that of ordinary neutron
stars. At the center of these stars, quarks are essentially massless.Comment: ReVTeX, 5 pages, 3 figure
The zeros of the QCD partition function
We establish a relationship between the zeros of the partition function in
the complex mass plane and the spectral properties of the Dirac operator in
QCD. This relation is derived within the context of chiral Random Matrix Theory
and applies to QCD when chiral symmetry is spontaneously broken. Further, we
introduce and examine the concept of normal modes in chiral spectra. Using this
formalism we study the consequences of a finite Thouless energy for the zeros
of the partition function. This leads to the demonstration that certain
features of the QCD partition function are universal.Comment: 13 page
Tantalum carbide as a novel support material for anode electrocatalysts in polymer electrolyte membrane water electrolysers
Colonialism, postcolonialism and the liberal welfare state
This article addresses the colonial and racial origins of the welfare state with a particular emphasis on the liberal welfare state of the USA and UK. Both are understood in terms of the centrality of the commodified status of labour power expressing a logic of market relations. In contrast, we argue that with a proper understanding of the relations of capitalism and colonialism, the sale of labour power as a commodity already represents a movement away from the commodified form of labour represented by enslavement. European colonialism is integral to the development of welfare states and their forms of inclusion and exclusion which remain racialised through into the twenty-first century
Indirect Inference for Dynamic Panel Models
Published in Journal of Econometrics, 2007, https://doi.org/10.1016/j.jeconom.2009.10.024</p
Detection of GRB 060927 at z = 5.47: Implications for the use of gamma-ray bursts as probes of the end of the dark ages
We report on follow-up observations of the gamma-ray burst GRB 060927 using the robotic ROTSE-IIIa telescope and a suite of larger aperture ground-based telescopes. An optical afterglow was detected 20 s after the burst, the earliest rest-frame detection of optical emission from any GRB. Spectroscopy performed with the VLT about 13 hr after the trigger shows a continuum break at λ ≈ 8070 Å, produced by neutral hydrogen absorption at z ≈ 5.6. We also detect an absorption line at 8158 Å, which we interpret as Si II λ1260 at z = 5.467. Hence, GRB 060927 is the second most distant GRB with a spectroscopically measured redshift. The shape of the red wing of the spectral break can be fitted by a damped Lyα profile with a column density with log (NH /cm-2) = 22.50 ±0.15. We discuss the implications of this work for the use of GRBs as probes of the end of the dark ages and draw three main conclusions: (1) GRB afterglows originating from z ≳ 6 should be relatively easy to detect from the ground, but rapid near-infrared monitoring is necessary to ensure that they are found; (2) the presence of large H I column densities in some GRB host galaxies at z \u3e 5 makes the use of GRBs to probe the reionization epoch via spectroscopy of the red damping wing challenging; and (3) GRBs appear crucial to locate typical star-forming galaxies at z \u3e 5, and therefore the type of galaxies responsible for the reionization of the universe. © 2007. The American Astronomical Society. All rights reserved
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