4,590 research outputs found

    Barriers to energy efficiency improvement: Empirical evidence from small-and-medium sized enterprises in China

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    This paper analyzes barriers for energy efficiency investments for small-and medium-sized enterprises (SMEs) in China. Based on a survey of 480 SMEs in Zhejiang Province, this study assesses financial, informational, and organizational barriers for energy efficiency investments in the SME sector. The conventional view has been that the lack of appropriate financing mechanisms particularly hinders SMEs to adopt cost-effective energy efficiency measures. As such, closing the financing gap for SMEs is seen as a prerequisite in order to promote energy efficiency in the sector. The econometric estimates of this study, however, suggest that access to information is an important determinant of investment outcomes, while this is less clear with respect to financial and organizational factors. More than 40 percent of enterprises in the sample declared that that they are not aware of energy saving equipments or practices in their respective business area, indicating that there are high transaction costs for SMEs to gather, assess, and apply information about energy saving potentials and relevant technologies. One implication is that the Chinese government may assume an active role in fostering the dissemination of energy-efficiency related information in the SME sector. --energy efficiency,SMEs,China,energy policies,information access

    Quantum phase transitions in rotating nuclei

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    We extend the classical Landau theory for rotating nuclei and show that the backbending in 162Yb, that comes about as a result of the two-quasiparticle alignment, is identified with the second order phase transition. We found that the backbending in 156Dy, caused by the instability of γ\gamma-vibrations in the rotating frame, corresponds to the first order phase transition.Comment: 4 pages, 2 figure

    The 85$Rb(p,n)85Sr reaction and the modified proton optical potential

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    The cross sections of the astrophysically relevant 85$Rb(p,n)85Srg,m reaction have been measured between Ec.m. = 2.16 and 3.96 MeV. The cross sections have been derived by measuring the gamma radiation following the beta decay of the reaction products. A comparison with the predictions of Hauser-Feshbach calculations using the NON-SMOKER code confirms a recently derived modification of the global optical proton potential.Comment: CGS XIII conferenc

    Gravitational Contributions to the Running Yang-Mills Coupling in Large Extra-Dimensional Brane Worlds

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    We study the question of a modification of the running gauge coupling of Yang-Mills theories due to quantum gravitational effects in a compact large extra dimensional brane world scenario with a low energy quantum gravity scale. The ADD scenario is applied for a D=d+\delta dimensional space-time in which gravitons freely propagate, whereas the non-abelian gauge fields are confined to a d-dimensional brane. The extra dimensions are taken to be toroidal and the transverse fluctuation modes (branons) of the brane are taken into account. On this basis we have calculated the one-loop corrections due to virtual Kaluza-Klein graviton and branon modes for the gluon two- and three-point functions in an effective field theory treatment. Applying momentum cut-off regularization we find that for a d=4 brane the leading gravitational divergencies cancel irrespective of the number of extra dimensions \delta, generalizing previous results in the absence of extra-dimensions. Hence, again the Yang-Mills \beta-function receives no gravitational corrections at one-loop. This is no longer true in a `universal' extra dimensional scenario with a d>4 dimensional brane. Moreover, the subleading power-law gravitational divergencies induce higher-dimensional counterterms, which we establish in our scheme. Interestingly, for d=4 these gravitationally induced counterterms are of the form recently considered in non-abelian Lee-Wick extensions of the standard model -- now with a possible mass scale in the TeV range due to the presence of large extra dimensions.Comment: Version to be published in JHEP; 16 pages, 3 figures; v3: references update

    Low-temperature properties of single-crystal CrB2_{2}

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    We report the low-temperature properties of 11^{11}B-enriched single-crystal CrB2_{2} as prepared from high-purity Cr and B powder by a solid-state reaction and optical float zoning. The electrical resistivity, ρxx\rho_{\rm xx}, Hall effect, ρxy\rho_{\rm xy}, and specific heat, CC, are characteristic of an exchange-enhanced Fermi liquid ground state, which develops a slightly anisotropic spin gap Δ220K\Delta \approx 220\,{\rm K} below TN=88KT_{\rm N}=88\,{\rm K}. This observation is corroborated by the absence of a Curie dependence in the magnetization for T0T\to0 reported in the literature. Comparison of CC with dρxx/dTd\rho_{\rm xx}/dT, where we infer lattice contributions from measurements of VB2_2, reveals strong antiferromagnetic spin fluctuations with a characteristic spin fluctuation temperature Tsf257KT_{\rm sf}\approx 257\,{\rm K} in the paramagnetic state, followed by a pronounced second-order mean-field transition at TNT_{\rm N}, and unusual excitations around TN/2\approx T_{\rm N}/2. The pronounced anisotropy of ρxx\rho_{\rm xx} above TNT_{\rm N} is characteristic of an easy-plane anisotropy of the spin fluctuations consistent with the magnetization. The ratio of the Curie-Weiss to the Neˊ\acute{\rm{e}}el temperatures, f=ΘCW/TN8.5f=-\Theta_{\rm CW}/T_{\rm N}\approx 8.5, inferred from the magnetization, implies strong geometric frustration. All physical properties are remarkably invariant under applied magnetic fields up to 14T14\,\,{\rm T}, the highest field studied. In contrast to earlier suggestions of local-moment magnetism our study identifies CrB2_{2} as a weak itinerant antiferromagnet par excellence with strong geometric frustration.Comment: 15 pages, 9 figure

    Evaluating sulfur-tolerance of metal/Ce0.80Gd0.20O1.90 co-impregnated La0.20Sr0.25Ca0.45TiO3 anodes for solid oxide fuel cells

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    The authors acknowledge funding from the University of St Andrews, HEXIS AG and the EPSRC Grants: EP/M014304/1 “Tailoring of Microstructural Evolution in Impregnated SOFC Electrodes” and EP/L017008/1 “Capital for Great Technologies”.The Ni-based cermet Solid Oxide Fuel Cell (SOFC) anode is prone to poisoning by sulfur-based odourising agents, and naturally occurring sulfur species, present in unprocessed natural gas feeds. Next generation SOFC anodes should be able to withstand exposure to these poisons in the event of a malfunction or breakdown of desulfurisation units. Here, we present results pertaining to the sulfur-tolerance of Ni/Ce0.80Gd0.20O1.90 (CGO), Pt/CGO and Rh/CGO co-impregnated La0.20Sr0.25Ca0.45TiO3 anode ‘backbone’ microstructures and their ability to recover performance after being exposed to H2S. The Ni/CGO co-impregnated system exhibited severe poisoning by H2S, however, the Rh/CGO system displayed good stability in Area Specific Resistance (ASR) upon introduction of 1–2 ppm of H2S and the Pt/CGO system showed minimal increases in ASR with the addition of 1–8 ppm H2S. Recovery measurements performed in non-humidified H2 at 300 mA cm−2, after exposure to 8 ppm H2S, indicated that the Pt/CGO and Rh/CGO systems could recover within 10 min, whilst 60 min were required to achieve almost a full recovery of performance for the Ni/CGO system. Additionally, all three impregnate systems showed good stability in operating voltage, after an initial drop, in a fuel gas containing simulated syngas (2:1 H2:CO) with 8 ppm H2S.PostprintPeer reviewe

    Tailored antiplatelet therapy can overcome clopidogrel and aspirin resistance - The BOchum CLopidogrel and Aspirin Plan (BOCLA-Plan) to improve antiplatelet therapy

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    <p>Abstract</p> <p>Background</p> <p>Dual antiplatelet therapy using acetylsalicylic acid (ASA, aspirin) and clopidogrel is of great importance following coronary stenting. However, the variable platelet inhibitory effectiveness compromises the antithrombotic advantages provided by dual antiplatelet therapy. The aim of this single-center prospective study was to reduce the low response incidence of dual antiplatelet therapy with ASA and clopidogrel according to a prespecified therapy algorithm.</p> <p>Methods</p> <p>Platelet function testing using whole blood aggregometry (Chronolog 590) was performed 48 hours following coronary stenting (for either acute coronary syndromes or stable coronary artery disease) on 504 patients. The antiplatelet therapy included a loading dose of 600 mg clopidogrel and 500 mg ASA, followed by 75 mg clopidogrel and 100 mg ASA once daily. Clopidogrel low responders (CLR: >5 ohm; adenosine diphosphate (ADP) 5 μM) and/or ASA low responders (ALR: >0 ohm; arachidonic acid 10 μM) were treated according to a structured therapy plan: in the case of CLR, the maintenance + dose was doubled (repeated loading dose followed by 150 mg daily), and when still ineffective ticlopidine or prasugrel, if available and not contraindicated, were used. ALR was treated by increasing the dose to 300 mg in a first step or to 500 mg ASA when the first modification did not take effect sufficiently. In addition, ADP receptor antagonist 2-methylthioadenosine 5'-monophosphate triethylammonium salt (MeSAMP) testing and ASA incubation were performed to rule out either a platelet ADP-receptor defect or an ASA pharmacokinetic resistance.</p> <p>Results</p> <p>Of the total cohort of 504 patients, we detected 30.8% clopidogrel low-responders and 19.4% aspirin low-responders. For ALR, with a dose adjustment of 300 mg ASA daily, 94.6% of ALR were effectively treated and the residual 5.4% by administration of daily dosages of 500 mg ASA. This means that after modification of the ASA maintenance dose, all initial ALRs had an adequate antiplatelet response.</p> <p>The results for clopidogrel revealed that 69% of the CLR were treated effectively by increasing the clopidogrel dose to 150 mg daily. When prasugrel was not available or contraindicated, 12.7% of the remaining low responders showed an adequate result after being switched to ticlopidine. Consequently, by applying the therapy algorithm, we were able to reduce the CLR prevalence by 86.6%. On including prasugrel in the therapy plan, we were finally able to eliminate thienopyridine low response. In addition, no ADP receptor defect was found in this study as a potential reason for CLR.</p> <p>We identified the following factors associated with both CLR and ALR status: acute coronary syndromes, positive troponin values as well as diabetes mellitus and elevated HbA<sub>1C </sub>values and a higher platelet count. Furthermore, our data revealed for CLR elevated C-reactive protein values and a high PREDICT-score (including an age >65 years, acute coronary syndrome, diabetes mellitus, renal failure, and reduced left ventricular function) as risk factors. The following factors correlated with the risk of ASA low response: patients with elevated hemoglobin, serum creatinine and C-reactive protein values. In addition, medication with nitrates reduced the risk of being CLR. As also holds true for CLR, we found the PREDICT-score to be correlated to the risk of being ALR. However, by far the strongest risk factor for CLR or ALR was the fact of dual resistance.</p> <p>Conclusion</p> <p>Following a structured therapy plan based on a "test and treat" strategy, the prevalence of clopidogrel or aspirin low response can be significantly reduced and the risk of inadequate dual antiplatelet therapy minimized.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01212302">NCT01212302</a> (Clinicaltrials.gov)</p

    Correlations between Optical Properties and Voronoi-Cell Area of Quantum Dots

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    A semiconductor quantum dot (QD) can generate highly indistinguishable single-photons at a high rate. For application in quantum communication and integration in hybrid systems, control of the QD optical properties is essential. Understanding the connection between the optical properties of a QD and the growth process is therefore important. Here, we show for GaAs QDs, grown by infilling droplet-etched nano-holes, that the emission wavelength, the neutral-to-charged exciton splitting, and the diamagnetic shift are strongly correlated with the capture zone-area, an important concept from nucleation theory. We show that the capture-zone model applies to the growth of this system even in the limit of a low QD-density in which atoms diffuse over μ\mum-distances. The strong correlations between the various QD parameters facilitate preselection of QDs for applications with specific requirements on the QD properties; they also suggest that a spectrally narrowed QD distribution will result if QD growth on a regular lattice can be achieved

    Tetra­ethyl­ammonium tricarbonyl­chlorido­(pyrazine-2-carboxyl­ato-N 1,O)rhenate(I)

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    In the title complex, (C8H20N)[Re(C5H3N2O2)Cl(CO)3], the ReI atom is coordinated facially by three carbonyl groups; the bidentate pyrazine­carboxyl­ato ligand and a chlorine atom complete the distorted octa­hedral coordination
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