15,764 research outputs found

    Carbon Trading with Blockchain

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    Blockchain has the potential to accelerate the deployment of emissions trading systems (ETS) worldwide and improve upon the efficiency of existing systems. In this paper, we present a model for a permissioned blockchain implementation based on the successful European Union (EU) ETS and discuss its potential advantages over existing technology. We propose an ETS model that is both backwards compatible and future-proof, characterised by interconnectedness, transparency, tamper-resistance and high liquidity. Further, we identify key challenges to implementation of a blockchain ETS, as well as areas of future work required to enable a fully-decentralised blockchain ETS

    Nuclear modification at sqrt{s_{NN}}=17.3 GeV, measured at NA49

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    Transverse momentum spectra up to 4.5 GeV/c were measured around midrapidity in Pb+Pb reactions at sqrt{s_{NN}}=17.3 GeV, for pi^{+/-}, p, pbar and K^{+/-}, by the NA49 experiment. The nuclear modification factors R_{AA}, R_{AA/pA} and R_{CP} were extracted and are compared to RHIC results at sqrt{s_{NN}}=200 GeV. The modification factor R_{AA} shows a rapid increase with transverse momentum in the covered region. The modification factor R_{CP} shows saturation well below unity in the pi^{+/-} channel. The extracted R_{CP} values follow the 200 GeV RHIC results closely in the available transverse momentum range for all particle species. For pi^{+/-} above 2.5 GeV/c transverse momentum, the measured suppression is smaller than that observed at RHIC. The nuclear modification factor R_{AA/pA} for pi^{+/-} stays well below unity.Comment: Proceedings of Quark Matter 2008 conferenc

    Event-by-Event Search for Charged Neutral Fluctuations in Pb - Pb Collisions at 158-A-GeV

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    Results from the analysis of data obtained from the WA98 experiment at the CERN SPS have been presented. Some events have been filtered which show photon excess in limited η−ϕ\eta-\phi zones within the overlap region of the charged particle and photon multiplicity detectors.Comment: 6 pages, 4 figure

    High temperature–high pressure thermal conductivities of ethylene and propane

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    Thermal conductivities λ of ethylene and propane were measured in the temperature and pressure ranges 400–750 K and 0.1–2.65 MPa (ethylene) and 400–725 K and 0.1 to 0.6 MPa (propane). The data were correlated by expressions of the form λ=λ0(T) ×λp(P), with λ0 being a second order polynomial in temperature and λp a third (ethylene) or a fourth (propane) order polynomial in pressure. The results obtained were compared with previous thermal conductivity measurements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71313/2/JCPSA6-70-8-3948-1.pd

    Interferometry of direct photons in Pb+Pb collisions at 158 AGeV

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    We present final results from the WA98 experiment which provide first measurements of Bose-Einstein correlations of direct photons in ultrarelativistic heavy ion collisions. Invariant interferometric radii were extracted in the range 100<KT<300100<K_T<300 MeV/c and compared to interferometric radii of charged pions. The yield of direct photons for 100<pT<300100<p_T<300 MeV/c was extracted from the correlation strength parameter and compared to the yield of direct photons measured in WA98 at higher pTp_T with the statistical subtraction method, and to predictions of a fireball model.Comment: 4 pages, 3 figures, proceedings for Quark Matter 200

    Tin(IV) Halide Complexes of Some Thiosemicarbazides

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    153-15

    Age-related decrease in rod bipolar cell density of the human retina: an immunohistochemical study

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    During normal ageing, the rods (and other neurones) undergo a significant decrease in density in the human retina from the fourth decade of life onward. Since the rods synapse with the rod bipolar cells in the outer plexiform layer, a decline in rod density (mainly due to death) may ultimately cause an associated decline of the neurones which, like the rod bipolar cells, are connected to them. The rod bipolar cells are selectively stained with antibodies to protein kinase C-α. This study examined if rod bipolar cell density changes with ageing of the retina, utilizing donor human eyes (age: 6-91 years). The retinas were fixed and their temporal parts from the macula to the mid-periphery sectioned and processed for protein kinase C-α immunohistochemistry. The density of the immunopositive rod bipolar cells was estimated in the mid-peripheral retina (eccentricity: 3-5 mm) along the horizontal temporal axis. The results show that while there is little change in the density of the rod bipolar cells from 6 to 35 years (2.2%), the decline during the period from 35 to 62 years is about 21% and between seventh and tenth decades, it is approximately 27%

    Approximate Minimum Diameter

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    We study the minimum diameter problem for a set of inexact points. By inexact, we mean that the precise location of the points is not known. Instead, the location of each point is restricted to a contineus region (\impre model) or a finite set of points (\indec model). Given a set of inexact points in one of \impre or \indec models, we wish to provide a lower-bound on the diameter of the real points. In the first part of the paper, we focus on \indec model. We present an O(21Ï”d⋅ϔ−2d⋅n3)O(2^{\frac{1}{\epsilon^d}} \cdot \epsilon^{-2d} \cdot n^3 ) time approximation algorithm of factor (1+Ï”)(1+\epsilon) for finding minimum diameter of a set of points in dd dimensions. This improves the previously proposed algorithms for this problem substantially. Next, we consider the problem in \impre model. In dd-dimensional space, we propose a polynomial time d\sqrt{d}-approximation algorithm. In addition, for d=2d=2, we define the notion of α\alpha-separability and use our algorithm for \indec model to obtain (1+Ï”)(1+\epsilon)-approximation algorithm for a set of α\alpha-separable regions in time O(21Ï”2.n3Ï”10.sin⁥(α/2)3)O(2^{\frac{1}{\epsilon^2}}\allowbreak . \frac{n^3}{\epsilon^{10} .\sin(\alpha/2)^3} )
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