A nearly zero-energy microgrid testbed laboratory: Centralized control strategy based on SCADA system

Currently, despite the use of renewable energy sources (RESs), distribution networks are facing problems, such as complexity and low productivity. Emerging microgrids (MGs) with RESs based on supervisory control and data acquisition (SCADA) are an effective solution to control, manage, and finally deal with these challenges. The development and success of MGs is highly dependent on the use of power electronic interfaces. The use of these interfaces is directly related to the progress of SCADA systems and communication infrastructures. The use of SCADA systems for the control and operation of MGs and active distribution networks promotes productivity and efficiency. This paper presents a real MG case study called the LAMBDA MG testbed laboratory, which has been implemented in the electrical department of the Sapienza University of Rome with a centralized energy management system (CEMS). The real-time results of the SCADA system show that a CEMS can create proper energy balance in a LAMBDA MG testbed and, consequently, minimize the exchange power of the LAMBDA MG and main grid

Strong electric fields induced on a sharp stellar boundary

Due to a first order phase transition, a compact star may have a discontinuous distribution of baryon as well as electric charge densities, as e.g. at the surface of a strange quark star. The induced separation of positive and negative charges may lead to generation of supercritical electric fields in the vicinity of such a discontinuity. We study this effect within a relativistic Thomas-Fermi approximation and demonstrate that the strength of the electric field depends strongly on the degree of sharpness of the surface. The influence of strong electric fields on the stability of compact stars is discussed. It is demonstrated that stable configurations appear only when the counter-pressure of degenerate fermions is taken into consideration.Comment: 13 pages, 2 figure

Impact of therapeutic choices on outcome of osteomyelitis caused by MRSA

Fifty-four patients with chronic osteomyelitis sustained by methicillin-resistant staphylococcus were treated with daptomycin, linezolid, or teicoplanin and observed over time. Median time to CRP normalization was 7 weeks for daptomycin, 8 weeks for linezolid, and 12 weeks for teicoplanin (X2 =14.1; p < 0.001). Cure rate (intention to treat analysis) was 83% for the cases receiving teicoplanin, 77% for those receiving linezolid and 92% for those receiving daptomycin. We conclude that daptomycin and linezolid have to be considered at least equivalent to teicoplanin for the treatment of MRSA osteomyelitis

Detectability of Strange Matter in Heavy Ion Experiments

We discuss the properties of two distinct forms of hypothetical strange matter, small lumps of strange quark matter (strangelets) and of hyperon matter (metastable exotic multihypernuclear objects: MEMOs), with special emphasis on their relevance for present and future heavy ion experiments. The masses of small strangelets up to A = 40 are calculated using the MIT bag model with shell mode filling for various bag parameters. The strangelets are checked for possible strong and weak hadronic decays, also taking into account multiple hadron decays. It is found that strangelets which are stable against strong decay are most likely highly negative charged, contrary to previous findings. Strangelets can be stable against weak hadronic decay but their masses and charges are still rather high. This has serious impact on the present high sensitivity searches in heavy ion experiments at the AGS and CERN facilities. On the other hand, highly charged MEMOs are predicted on the basis of an extended relativistic mean-field model. Those objects could be detected in future experiments searching for short-lived, rare composites. It is demonstrated that future experiments can be sensitive to a much wider variety of strangelets.Comment: 26 pages, 5 figures, uses RevTeX and epsf.st

Search for the Weak Decay of an H Dibaryon

We have searched for a neutral $H$ dibaryon decaying via $H\to\Lambda n$ and $H\to\Sigma^0 n$. Our search has yielded two candidate events from which we set an upper limit on the $H$ production cross section. Normalizing to the inclusive $\Lambda$ production cross section, we find $(d\sigma_H/d\Omega) / (d\sigma_\Lambda/d\Omega) < 6.3\times 10^{-6}$ at 90% C.L., for an $H$ of mass $\approx$ 2.15 GeV/$c^2$.Comment: 11 pages, 6 postscript figures, epsfig, aps, preprint, revte

Measurement of Branching Fractions and Rate Asymmetries in the Rare Decays B -> K(*) l+ l-

In a sample of 471 million BB events collected with the BABAR detector at the PEP-II e+e- collider we study the rare decays B -> K(*) l+ l-, where l+ l- is either e+e- or mu+mu-. We report results on partial branching fractions and isospin asymmetries in seven bins of di-lepton mass-squared. We further present CP and lepton-flavor asymmetries for di-lepton masses below and above the J/psi resonance. We find no evidence for CP or lepton-flavor violation. The partial branching fractions and isospin asymmetries are consistent with the Standard Model predictions and with results from other experiments.Comment: 16 pages, 14 figures, accepted by Phys. Rev.

Improved Limits on B0B^{0} decays to invisible (+γ)(+\gamma) final states

We establish improved upper limits on branching fractions for B0 decays to final States 10 where the decay products are purely invisible (i.e., no observable final state particles) and for final states where the only visible product is a photon. Within the Standard Model, these decays have branching fractions that are below the current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions for these channels. Using 471 million BB pairs collected at the Y(4S) resonance by the BABAR experiment at the PEP-II e+e- storage ring at the SLAC National Accelerator Laboratory, we establish upper limits at the 90% confidence level of 2.4x10^-5 for the branching fraction of B0-->Invisible and 1.7x10^-5 for the branching fraction of B0-->Invisible+gammaComment: 8 pages, 3 postscript figures, submitted to Phys. Rev. D (Rapid Communications

Precise Measurement of the e+ e- --> pi+ pi- (gamma) Cross Section with the Initial-State Radiation Method at BABAR

A precise measurement of the cross section of the process $e^+e^-\to\pi^+\pi^-(\gamma)$ from threshold to an energy of 3GeV is obtained with the initial-state radiation (ISR) method using 232fb$^{-1}$ of data collected with the BaBar detector at $e^+e^-$ center-of-mass energies near 10.6GeV. The ISR luminosity is determined from a study of the leptonic process $e^+e^-\to\mu^+\mu^-(\gamma)\gamma_{\rm ISR}$, which is found to agree with the next-to-leading-order QED prediction to within 1.1%. The cross section for the process $e^+e^-\to\pi^+\pi^-(\gamma)$ is obtained with a systematic uncertainty of 0.5% in the dominant $\rho$ resonance region. The leading-order hadronic contribution to the muon magnetic anomaly calculated using the measured $\pi\pi$ cross section from threshold to 1.8GeV is $(514.1 \pm 2.2({\rm stat}) \pm 3.1({\rm syst}))\times 10^{-10}$.Comment: 58 pages, 56 figures, to be submitted to Phys. Rev.

Search for lepton-number violating processes in B+ -> h- l+ l+ decays

We have searched for the lepton-number violating processes B+ -> h- l+ l+ with h- = K-/pi- and l+ = e+/mu+, using a sample of 471+/-3 million BBbar events collected with the BaBar detector at the PEP-II e+e- collider at the SLAC National Accelerator Laboratory. We find no evidence for these decays and place 90% confidence level upper limits on their branching fractions Br(B+ -> pi- e+ e+) K- e+ e+) pi- mu+ mu+) K- mu+ mu+) < 6.7 x 10^{-8}.Comment: 8 pages, 4 postscript figures, submitted to Phys. Rev. D. R