360 research outputs found

    Analysis of the payback period of a modernized pump unit with induction electric motors of advanced energy efficiency classes

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    Aim. The comparative analysis of energy consumption, electricity costs during lifetime cycle and payback period of a pump unit with 90 kW 2-pole induction motors, belonging to various energy efficiency classes, feeding directly from power grid. Methods. The examined operating modes aligned with a typical operating cycle of a pump unit with approximately constant flow rate of 75-110 % of the rated flow. The calculations were based on the pump and induction motors nameplate data, which, in their turn, were based on the manufacturers’ experimental data. Results. The calculations of energy consumption, electricity costs and payback periods of a pump unit with 90 kW 2-pole induction motors, feeding directly from power grid have been performed in the article. The application of induction motors belonging to IE2, IE3 and IE4 energy efficiency classes has been discussed. Practical value. It has been demonstrated, than in case of replacement of an induction motor of energy efficiency class IE2 due to planned retrofit, payback period for an IE4 induction motor is 2.18 years, energy savings within a calculated 20-year operating period are 268MW·h, which makes €41110 in money terms. Under the same conditions, the replacement of an induction motor of energy efficiency class IE2 with an induction motor of energy efficiency class IE3 will allow to save 88 MW·h within a calculated operating period, which, expressed in monetary terms, is €13500 and the payback period is 5.11 years. Thus, the article proves that despite a higher initial price, the choice of an induction motor of energy efficiency class IE4 tends to be more economically advantageous

    Анализ срока окупаемости модернизированной насосной установки при использовании асинхронных двигателей повышенных классов энергоэффективности

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    Aim. The comparative analysis of energy consumption, electricity costs during lifetime cycle and payback period of a pump unit with 90 kW 2-pole induction motors, belonging to various energy efficiency classes, feeding directly from power grid. Methods. The examined operating modes aligned with a typical operating cycle of a pump unit with approximately constant flow rate of 75-110 % of the rated flow. The calculations were based on the pump and induction motors nameplate data, which, in their turn, were based on the manufacturers’ experimental data. Results. The calculations of energy consumption, electricity costs and payback periods of a pump unit with 90 kW 2-pole induction motors, feeding directly from power grid have been performed in the article. The application of induction motors belonging to IE2, IE3 and IE4 energy efficiency classes has been discussed. Practical value. It has been demonstrated, than in case of replacement of an induction motor of energy efficiency class IE2 due to planned retrofit, payback period for an IE4 induction motor is 2.18 years, energy savings within a calculated 20-year operating period are 268MW·h, which makes €41110 in money terms. Under the same conditions, the replacement of an induction motor of energy efficiency class IE2 with an induction motor of energy efficiency class IE3 will allow to save 88 MW·h within a calculated operating period, which, expressed in monetary terms, is €13500 and the payback period is 5.11 years. Thus, the article proves that despite a higher initial price, the choice of an induction motor of energy efficiency class IE4 tends to be more economically advantageous.Цель. Сравнительный анализ расчетов энергопотребления, затрат на электроэнергию в течение жизненного цикла и сроков окупаемости насосной установки с 2-полюсными асинхронными электродвигателями мощностью 90 кВт различных классов энергоэффективности, питающимися напрямую от электрической сети. Методика Рассматриваемые режимы работы соответствовали типовому циклу работы, характерному для насосных установок с приблизительно постоянным расходом 75-110 % от номинального. Расчет основывался на паспортных данных насоса и электродвигателей, которые в свою очередь основаны на экспериментальных данных производителей. Результат В статье произведен расчеты энергопотребления, затрат на электроэнергию и сроков окупаемости насосной установки с 2-полюсными асинхронными электродвигателями мощностью 90 кВт, питающимися напрямую от электрической сети. Рассмотрено применение электродвигателей с классами энергоэффективности IE2, IE3 и IE4. Практическое значение. Показано, что в случае замены электродвигателя класса энергоэффективности IE2 в связи с плановой модернизацией электродвигателем класса энергоэффективности IE4 срок окупаемости для электродвигателя класса энергоэффективности IE4 составляет 2,18 года, экономия электроэнергии в течение расчетного 20-летнего срока эксплуатации составляет 268 МВт·ч, что в денежном выражении составляет 41110 €. При тех же условиях замена электродвигателя класса энергоэффективности IE2 на электродвигатель класса энергоэффективности IE3 позволит достичь экономии электроэнергии в течение расчетного срока эксплуатации 88 МВт·ч, что составляет в денежном выражении 13500 €, и срока окупаемости 5,11 года. Таким образом, в статье показано, что, несмотря на более высокую начальную стоимость, выбор электродвигателя класса энергоэффективности IE4 более выгоден с экономической точки зрения

    Global Search for New Physics with 2.0/fb at CDF

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    Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with the standard model prediction. A model-independent approach (Vista) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for "bumps" that could indicate resonant production of new particles; and the Sleuth procedure scans for data excesses at large summed transverse momentum. This combined global search for new physics in 2.0/fb of ppbar collisions at sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.Comment: 8 pages, 7 figures. Final version which appeared in Physical Review D Rapid Communication

    Observation of Orbitally Excited B_s Mesons

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    We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

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    Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02

    Measurement of the top pair production cross section in 8 TeV proton-proton collisions using kinematic information in the lepton plus jets final state with ATLAS

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    A measurement is presented of the ttˉt\bar{t} inclusive production cross-section in pppp collisions at a center-of-mass energy of s=8\sqrt{s}=8 TeV using data collected by the ATLAS detector at the CERN Large Hadron Collider. The measurement was performed in the lepton+jets final state using a data set corresponding to an integrated luminosity of 20.3 fb1^{-1}. The cross-section was obtained using a likelihood discriminant fit and bb-jet identification was used to improve the signal-to-background ratio. The inclusive ttˉt\bar{t} production cross-section was measured to be 260±1(stat.)23+22(syst.)±8(lumi.)±4(beam)260\pm 1{\textrm{(stat.)}} ^{+22}_{-23} {\textrm{(syst.)}}\pm 8{\textrm{(lumi.)}}\pm 4{\mathrm{(beam)}} pb assuming a top-quark mass of 172.5 GeV, in good agreement with the theoretical prediction of 25315+13253^{+13}_{-15} pb. The ttˉ(e,μ)+jetst\bar{t}\to (e,\mu)+{\mathrm{jets}} production cross-section in the fiducial region determined by the detector acceptance is also reported.Comment: Published version, 19 pages plus author list (35 pages total), 3 figures, 2 tables, all figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2013-06

    Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

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    The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

    A search for resonances decaying into a Higgs boson and a new particle X in the XH → qqbb final state with the ATLAS detector

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    A search for heavy resonances decaying into a Higgs boson (H) and a new particle (X) is reported, utilizing 36.1 fb−1 of proton–proton collision data at collected during 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. The particle X is assumed to decay to a pair of light quarks, and the fully hadronic final state is analysed. The search considers the regime of high XH resonance masses, where the X and H bosons are both highly Lorentz-boosted and are each reconstructed using a single jet with large radius parameter. A two-dimensional phase space of XH mass versus X mass is scanned for evidence of a signal, over a range of XH resonance mass values between 1 TeV and 4 TeV, and for X particles with masses from 50 GeV to 1000 GeV. All search results are consistent with the expectations for the background due to Standard Model processes, and 95% CL upper limits are set, as a function of XH and X masses, on the production cross-section of the resonance

    Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

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    This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented
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