Impacts of harmonic distortion from charging electric vehicles on low voltage networks

Paper focusing on the impacts of harmonic distortion from charging electric vehicles on low voltage networks

Rotation Curves of Spiral Galaxies

Rotation curves of spiral galaxies are the major tool for determining the distribution of mass in spiral galaxies. They provide fundamental information for understanding the dynamics, evolution and formation of spiral galaxies. We describe various methods to derive rotation curves, and review the results obtained. We discuss the basic characteristics of observed rotation curves in relation to various galaxy properties, such as Hubble type, structure, activity, and environment.Comment: 40 pages, 6 gif figures; Ann. Rev. Astron. Astrophys. Vol. 39, p.137, 200

Observed communication semantics for classical processes

Classical Linear Logic (CLL) has long inspired readings of its proofs as communicating processes. Wadler's CP calculus is one of these readings. Wadler gave CP an operational semantics by selecting a subset of the cut-elimination rules of CLL to use as reduction rules. This semantics has an appealing close connection to the logic, but does not resolve the status of the other cut-elimination rules, and does not admit an obvious notion of observational equivalence. We propose a new operational semantics for CP based on the idea of observing communication, and use this semantics to define an intuitively reasonable notion of observational equivalence. To reason about observational equivalence, we use the standard relational denotational semantics of CLL. We show that this denotational semantics is adequate for our operational semantics. This allows us to deduce that, for instance, all the cut-elimination rules of CLL are observational equivalences

Search for Yukawa Production of a Light Neutral Higgs Boson at LEP

Within a Two-Higgs-Doublet Model (2HDM) a search for a light Higgs boson in the mass range of 4-12 GeV has been performed in the Yukawa process e+e- -> b bbar A/h -> b bbar tau+tau-, using the data collected by the OPAL detector at LEP between 1992 and 1995 in e+e- collisions at about 91 GeV centre-of-mass energy. A likelihood selection is applied to separate background and signal. The number of observed events is in good agreement with the expected background. Within a CP-conserving 2HDM type II model the cross-section for Yukawa production depends on xiAd = |tan beta| and xihd = |sin alpha/cos beta| for the production of the CP-odd A and the CP-even h, respectively, where tan beta is the ratio of the vacuum expectation values of the Higgs doublets and alpha is the mixing angle between the neutral CP-even Higgs bosons. From our data 95% C.L. upper limits are derived for xiAd within the range of 8.5 to 13.6 and for xihd between 8.2 to 13.7, depending on the mass of the Higgs boson, assuming a branching fraction into tau+tau- of 100%. An interpretation of the limits within a 2HDM type II model with Standard Model particle content is given. These results impose constraints on several models that have been proposed to explain the recent BNL measurement of the muon anomalous magnetic moment.Comment: 24 pages, 9 figures, Submitted to Euro. Phys. J.

The Global Dynamics of Inequality (GINI) project: analysing archaeological housing data

The GINI project investigates the dynamics of inequality among populations over the long term by synthesising global archaeological housing data. This project brings archaeologists together from around the world to assess hypotheses concerning the causes and consequences of inequality that are of relevance to contemporary societies globally

Measurement of the Hadronic Cross-Section for the Scattering of Two Virtual Photons at LEP

The interaction of virtual photons is investigated using the reaction e+e- -> e+e- hadrons based on data taken by the OPAL experiment at e+e- centre-of-mass energies sqrt(s_ee)=189-209 GeV, for W>5 GeV and at an average Q^2 of 17.9 GeV^2. The measured cross-sections are compared to predictions of the Quark Parton Model (QPM), to the Leading Order QCD Monte Carlo model PHOJET to the NLO prediction for the reaction e+e- -> e+e-qqbar, and to BFKL calculations. PHOJET, NLO e+e- -> e+e-qqbar, and QPM describe the data reasonably well, whereas the cross-section predicted by a Leading Order BFKL calculation is too large.Comment: 30 pages, 10 figures, Submitted to Eur.Phys.J.

Measurement of triple gauge boson couplings from WW production at LEP energies up to 189 GeV

A measurement of triple gauge boson couplings is presented, based on W-pair data recorded by the OPAL detector at LEP during 1998 at a centre-of-mass energy of 189 GeV with an integrated luminosity of 183 pb^-1. After combining with our previous measurements at centre-of-mass energies of 161-183 GeV we obtain k_g=0.97 +0.20 -0.16, g_1^z=0.991 +0.060 -0.057 and lambda_g=-0.110 +0.058 -0.055, where the errors include both statistical and systematic uncertainties and each coupling is determined by setting the other two couplings to their SM values. These results are consistent with the Standard Model expectations.Comment: 28 pages, 8 figures, submitted to Eur. Phys. J.

Search for Neutral Higgs Bosons in e+e- Collisions at sqrt(s) ~189GeV

A search for neutral Higgs bosons has been performed with the OPAL detector at LEP, using approximately 170 pb-1 of e+e- collision data collected at sqrt(s)~189GeV. Searches have been performed for the Standard Model (SM) process e+e- to H0Z0 and the MSSM processes e+e- to H0Z0, A0h0. The searches are sensitive to the b b-bar and tau antitau decay modes of the Higgs bosons, and also to the MSSM decay mode h0 to A0A0. OPAL search results at lower centre-of-mass energies have been incorporated in the limits we set, which are valid at the 95% confidence level. For the SM Higgs boson, we obtain a lower mass bound of 91.0 GeV. In the MSSM, our limits are mh>74.8GeV and mA>76.5GeV, assuming tan(beta)>1, that the mixing of the scalar top quarks is either zero or maximal, and that the soft SUSY-breaking masses are 1 TeV. For the case of zero scalar top mixing, we exclude values of tan(beta) between 0.72 and 2.19.Comment: 38 pages, 15 figures, submitted Euro. Phys. J.