Non-equilibrium radiation nuclear reactor

An externally moderated thermal nuclear reactor is disclosed which is designed to provide output power in the form of electromagnetic radiation. The reactor is a gaseous fueled nuclear cavity reactor device which can operate over wide ranges of temperature and pressure, and which includes the capability of processing and recycling waste products such as long-lived transuranium actinides. The primary output of the device may be in the form of coherent radiation, so that the reactor may be utilized as a self-critical nuclear pumped laser

A Lower Estimate for the Modified Steiner Functional

We prove inequality (1) for the modified Steiner functional A(M), which extends the notion of the integral of mean curvature for convex surfaces.We also establish an exression for A(M) in terms of an integral over all hyperplanes intersecting the polyhedralral surface M.Comment: 6 pages, Late

A Note on Asymptotic Freedom at High Temperatures

This short note considers, within the external field approach outlined in hep-ph/0202026, the role of the lowest lying gluon Landau mode in QCD in the high temperature limit. Its influence on a temperature- and field-dependent running coupling constant is examined. The thermal imaginary part of the mode is temperature-independent in our approach and exactly cancels the well-known zero temperature imaginary part, thus rendering the Savvidy vacuum stable. Combining the real part of the mode with the contributions from the higher lying Landau modes and the vacuum contribution, a field-independent coupling alpha_s(T) is obtained. It can be interpreted as the ordinary zero temperature running coupling constant with average thermal momenta \approx 2pi T for gluons and \approx pi T for quarks.Comment: 4 pages; minor changes, version to appear in Phys. Rev.

Limits on Pop III star formation with the most iron-poor stars

We study the impact of star-forming mini-haloes, and the Initial Mass Function (IMF) of Population III (Pop III) stars, on the Galactic halo Metallicity Distribution Function (MDF) and on the properties of C-enhanced and C-normal stars at [Fe/H]<-3. For our investigation we use a data-constrained merger tree model for the Milky Way formation, which has been improved to self-consistently describe the physical processes regulating star-formation in mini-haloes, including the poor sampling of the Pop III IMF. We find that only when star-forming mini-haloes are included the low-Fe tail of the MDF is correctly reproduced, showing a plateau that is built up by C-enhanced metal-poor (CEMP) stars imprinted by primordial faint supernovae. The incomplete sampling of the Pop III IMF in inefficiently star-forming mini-haloes (< $10^{-3}$ $M_\odot$/yr) strongly limits the formation of Pair Instability Supernovae (PISNe), with progenitor masses $m_{\rm popIII}$=[140-260] $M_\odot$, even when a flat Pop III IMF is assumed. Second-generation stars formed in environments polluted at >50% level by PISNe are thus extremely rare, corresponding to $\approx$ 0.25% of the total stellar population at [Fe/H]<-2, which is consistent with recent observations. The low-Fe tail of the MDF strongly depends on the Pop III IMF shape and mass range. Given the current statistics, we find that a flat Pop III IMF model with $m_{\rm popIII}$=[10-300] $M_\odot$ is disfavoured by observations. We present testable predictions for Pop III stars extending down to lower masses, with $m_{\rm popIII}$=[0.1-300] $M_\odot$.Comment: 15 pages, 11 figures. Accepted for publication in MNRAS. The only change is the correction of a mistake in the list of author

Research into practice : collaboration for leadership in applied health research and care (CLAHRC) for Nottinghamshire, Derbyshire, Lincolnshire (NDL)

To address the problem of translation from research-based evidence to routine healthcare practice, the Collaboration for Leadership in Applied Health Research and Care for Nottinghamshire, Derbyshire, and Lincolnshire (CLAHRC-NDL) was funded by the National Institute for Health Research as one of nine CLAHRCs across England. This paper outlines the underlying theory and its application that CLAHRC-NDL has adopted, as a case example that might be generalised to practice outside the CLAHRC, in comparison to alternative models of implementation

A Comparison of Phycocyanins from Three Different Species of Cyanobacteria Employing Resonance-Enhanced Coherent Anti-Stokes Raman Spectroscopy

Resonance-enhanced coherent anti-Stokes Raman spectra are recorded for monomers and trimers of phycocyanin from three different cyanobacteria: Westiellopsis prolifica, Mastigocladus laminosus and Spirulina platensis. It is shown that upon aggregation from monomer to trimer the electronic structures of both the α84 and β84 chromophores are changed. The spectra of the trimers originating from S. platensis and M. laminosus are very similar to each other, but distinctly different from the spectrum of W. prolifica

Exploiting the Temporal Logic Hierarchy and the Non-Confluence Property for Efficient LTL Synthesis

The classic approaches to synthesize a reactive system from a linear temporal logic (LTL) specification first translate the given LTL formula to an equivalent omega-automaton and then compute a winning strategy for the corresponding omega-regular game. To this end, the obtained omega-automata have to be (pseudo)-determinized where typically a variant of Safra's determinization procedure is used. In this paper, we show that this determinization step can be significantly improved for tool implementations by replacing Safra's determinization by simpler determinization procedures. In particular, we exploit (1) the temporal logic hierarchy that corresponds to the well-known automata hierarchy consisting of safety, liveness, Buechi, and co-Buechi automata as well as their boolean closures, (2) the non-confluence property of omega-automata that result from certain translations of LTL formulas, and (3) symbolic implementations of determinization procedures for the Rabin-Scott and the Miyano-Hayashi breakpoint construction. In particular, we present convincing experimental results that demonstrate the practical applicability of our new synthesis procedure