80 research outputs found

    Clan Structure Analysis and Rapidity Gap Probability

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    Clan structure analysis in rapidity intervals is generalized from negative binomial multiplicity distribution to the wide class of compound Poisson distributions. The link of generalized clan structure analysis with correlation functions is also established. These theoretical results are then applied to minimum bias events and evidentiate new interesting features, which can be inspiring and useful in order to discuss data on rapidity gap probability at TEVATRON and HERA.Comment: (14 pages in Plain TeX plus 5 Postscript Figures, all compressed via uufiles) DFTT 28/9

    How are nature-based solutions contributing to priority societal challenges surrounding human well-being in the United Kingdom: a systematic map

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    Background The concept of nature-based solutions (NBS) has evolved as an umbrella concept to describe approaches to learning from and using nature to create sustainable socio-ecological systems. Furthermore, NBS often address multiple societal challenges that humans are facing in the medium to long-term and as such can enhance human well-being (HWB). This study was commissioned to fulfil the need for a targeted systematic evidence map on the linkage between NBS and HWB to support focused research going forward that addresses the key knowledge needs of policy makers in the UK and beyond. Methods A consultation with policy makers and government agency staff (n = 46), in the four component parts of the UK (England, Wales, Scotland, Northern Ireland) was conducted in spring 2019. This identified four key societal challenges of operational experience lacking a scientific evidence base. Three of these challenges related to management issues: NBS cost-efficacy, governance in planning, environmental justice. The fourth challenge related to the acoustic environment (soundscape). Using systematic methods, this study searched for and identified studies that assessed NBS on HWB with regard to these four selected societal challenges. Review findings A total of 7287 articles were returned from the systematic search and screened for suitability at the level of title and abstract. A total of 610 articles passed screening criteria to warrant full text screening. Of these, 115 studies met the full text criteria for eligibility in the final systematic map database. Included studies were coded for twelve NBS interventions and ten HWB related outcome categories. Most of the evidence reviewed referred to natural, blue or green infrastructure in the urban environment and focused on economic, material and health aspects of HWB. Less than 2% of studies identified in the searches robustly reported the role of NBS actions or interventions on HWB compared with non-NBS actions or interventions Conclusion This systematic map found the evidence base is growing on NBS-HWB linkages, but significant biases persist in the existing literature. There was a bias in favour of the urban environment and restoration studies focused on conservation aspects, with only a few studies investigating the full suite of advantages to HWB that can be delivered from NBS actions and interventions. The soundscape was the least studied of the societal challenges identified as being of key importance by policy makers, with cost-efficiency the most reported. There was a lack of robust long-term studies to clearly test the potential of NBS regarding the HWB outcomes compared with non-NBS alternatives. This lack of robust primary knowledge, covering all four key societal challenges identified, confirms that the knowledge gaps identified by the policy makers persist, and highlights a clear research need for long-term, transdisciplinary studies that focus on comparisons between NBS and non-NBS alternative

    UV and EUV Instruments

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    We describe telescopes and instruments that were developed and used for astronomical research in the ultraviolet (UV) and extreme ultraviolet (EUV) regions of the electromagnetic spectrum. The wavelength ranges covered by these bands are not uniquely defined. We use the following convention here: The EUV and UV span the regions ~100-912 and 912-3000 Angstroem respectively. The limitation between both ranges is a natural choice, because the hydrogen Lyman absorption edge is located at 912 Angstroem. At smaller wavelengths, astronomical sources are strongly absorbed by the interstellar medium. It also marks a technical limit, because telescopes and instruments are of different design. In the EUV range, the technology is strongly related to that utilized in X-ray astronomy, while in the UV range the instruments in many cases have their roots in optical astronomy. We will, therefore, describe the UV and EUV instruments in appropriate conciseness and refer to the respective chapters of this volume for more technical details.Comment: To appear in: Landolt-Boernstein, New Series VI/4A, Astronomy, Astrophysics, and Cosmology; Instruments and Methods, ed. J.E. Truemper, Springer-Verlag, Berlin, 201

    DCC dynamics with the SU(3) linear sigma model

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    The SU(3) extension of the linear sigma model is employed to elucidate the effect of including strangeness on the formation of disoriented chiral condensates. By means of a Hartree factorization, approximate dispersion relations for the 18 scalar and pseudoscalar meson species are derived and their self-consistent solution makes it possible to trace out the thermal path of the two order parameters as well as delineate the region of instability within which spontaneous pair creation becomes possible. The results depend significantly on the employed sigma mass, with the highest values yielding the largest regions of instability. An approximate solution of the equations of motion for the order parameter in scenarios emulating uniform scaling expansions show that even with a rapid quench only the pionic modes grow unstable. Nevertheless, the rapid and oscillatory relaxation of the order parameters leads to enhanced production of both pions and (to a lesser degree) kaons.Comment: 29 pages, RevTeX, 11 postscript figures, discussion about anomaly term adde

    On the Consequences of Retaining the General Validity of Locality in Physical Theory

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    The empirical validity of the locality (LOC) principle of relativity is used to argue in favour of a local hidden variable theory (HVT) for individual quantum processes. It is shown that such a HVT may reproduce the statistical predictions of quantum mechanics (QM), provided the reproducibility of initial hidden variable states is limited. This means that in a HVT limits should be set to the validity of the notion of counterfactual definiteness (CFD). This is supported by the empirical evidence that past, present, and future are basically distinct. Our argumentation is contrasted with a recent one by Stapp resulting in the opposite conclusion, i.e. nonlocality or the existence of faster-than-light influences. We argue that Stapp's argumentation still depends in an implicit, but crucial, way on both the notions of hidden variables and of CFD. In addition, some implications of our results for the debate between Bohr and Einstein, Podolsky and Rosen are discussed.Comment: revtex, 11 page

    Dense carbon monoliths for supercapacitors with outstanding volumetric capacitances

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    A commercially available dense carbon monolith (CM) and four carbon monoliths obtained from it have been studied as electrochemical capacitor electrodes in a two-electrode cell. CM has: (i) very high density (1.17 g cm−3), (ii) high electrical conductivity (9.3 S cm−1), (iii) well-compacted and interconnected carbon spheres, (iv) homogeneous microporous structure and (v) apparent BET surface area of 957 m2g−1. It presents interesting electrochemical behaviors (e.g., excellent gravimetric capacitance and outstanding volumetric capacitance). The textural characteristics of CM (porosity and surface chemistry) have been modified by means of different treatments. The electrochemical performances of the starting and treated monoliths have been analyzed as a function of their porous textures and surface chemistry, both on gravimetric and volumetric basis. The monoliths present high specific and volumetric capacitances (292 F g−1 and 342 F cm−3), high energy densities (38 Wh kg−1 and 44 Wh L−1), and high power densities (176 W kg−1 and 183 W L−1). The specific and volumetric capacitances, especially the volumetric capacitance, are the highest ever reported for carbon monoliths. The high values are achieved due to a suitable combination of density, electrical conductivity, porosity and oxygen surface content.Financial support from projects MAT2011-25198, MP1004 and PROMETEO/2009/047 is gratefully acknowledged. V.B. thanks MINECO for R&C contract

    Formation of dense partonic matter in relativistic nucleus-nucleus collisions at RHIC: Experimental evaluation by the PHENIX collaboration

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    Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (p_T), elliptic flow, two-particle correlations, non-statistical fluctuations, and suppression of particle production at high p_T. The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.Comment: 510 authors, 127 pages text, 56 figures, 1 tables, LaTeX. Submitted to Nuclear Physics A as a regular article; v3 has minor changes in response to referee comments. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
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