[en] Transient stability analysis of synchronous generator used in power station, connected to infinite bus, before and after balanced circuit fault is one of the main issues in power system security and operation. Short circuit fault is a very common transient that the synchronous generator faces. In this work the behavior of the synchronous generator under this transient is examined. Active power, terminal voltage and angular speed are measured and the model is implemented during steady state and transient periods using SIMULINK. The voltage, power, rotor angle and angular frequency behaviors are plotted and analyzed. The analysis shows that the generator is capable of regaining synchronism after the short circuit transient. The transient is damped within few seconds. Although, the final steady state values of the power and terminal voltage are slightly different from the initial values, the behavior of generator in consideration is satisfactory. (author)

[en] We present the search for Cherenkov signatures from relativistic magnetic monopoles in data taken with the AMANDA-II detector, a neutrino telescope deployed in the Antarctic ice cap at the Geographic South Pole. The non-observation of a monopole signal in data collected during the year 2000 improves present experimental limits on the flux of relativistic magnetic monopoles: Our flux limit varies between 3.8 x 10^-17 cm^-2 s^-1 sr^-1 (for monopoles moving at the vacuum speed of light) and 8.8 x 10^-16 cm^-2 s^-1 sr^-1 (for monopoles moving at a speed β=v/c=0.76, just above the Cherenkov threshold in ice). These limits apply to monopoles that are energetic enough to penetrate the Earth and enter the detector from below the horizon. The limit obtained for monopoles reaching the detector from above the horizon is less stringent by roughly an order of magnitude, due to the much larger background from down-going atmospheric muons. This looser limit is however valid for a larger class of magnetic monopoles, since the monopoles are not required to pass through the Earth. (orig.)

[en] Summary. The spatial structure of ACTH-(6-9)-PGP molecule has been investigated using theoretical conformational analysis method. Amino acid sequence of the N-terminal pentapeptide fragment of His-Phe-Arg-Trp-Pro of this molecule conforms to the fragment 6-9 of ACTH hormone. Calculations of conformational states of this molecule are carried out regarding nonvalent, electrostatic and torsional interactions and the energy of hydrogen bonds. The spatial structure of the His-Phe-Arg-Trp-Pro-Gly-Pro molecule was estimated on the low–energy conformations of the Nterminal tetrapeptide fragment His-Phe-Arg-Trp and C-terminal tripeptide fragment Pro-Gly-Pro of this molecule. It is shown that the spatial structure of heptapeptide molecule can be presented by 11 low-energy forms of the main chain. The low–energy conformations of this molecule, the values of dihedral angles of the backbone and side chains of the amino acid residues were founded and the energies of intra- and inter-residual interactions were determined. (author)

[en] The reconstruction of event-level information, such as the direction or energy of a neutrino interacting in IceCube DeepCore, is a crucial ingredient to many physics analyses. Algorithms to extract this high level information from the detector's raw data have been successfully developed and used for high energy events. In this work, we address unique challenges associated with the reconstruction of lower energy events in the range of a few to hundreds of GeV and present two separate, state-of-the-art algorithms. One algorithm focuses on the fast directional reconstruction of events based on unscattered light. The second algorithm is a likelihood-based multipurpose reconstruction offering superior resolutions, at the expense of larger computational cost.

[en] High-energy tau neutrinos are rarely produced in atmospheric cosmic-ray showers or at cosmic particle accelerators, but are expected to emerge during neutrino propagation over cosmic distances due to flavor mixing. When high energy tau neutrinos interact inside the IceCube detector, two spatially separated energy depositions may be resolved, the first from the charged current interaction and the second from the tau lepton decay. We report a novel analysis of 7.5 years of IceCube data that identifies two candidate tau neutrinos among the 60 "High-Energy Starting Events" (HESE) collected during that period. The HESE sample offers high purity, all-sky sensitivity, and distinct observational signatures for each neutrino flavor, enabling a new measurement of the flavor composition. The measured astrophysical neutrino flavor composition is consistent with expectations, and an astrophysical tau neutrino flux is indicated at 2.8σ significance.

[en] Atmospheric muon neutrinos are produced by meson decays in cosmic-ray-induced air showers. The flux depends on meteorological quantities such as the air temperature, which affects the density of air. Competition between decay and re-interaction of those mesons in the first particle production generations gives rise to a higher neutrino flux when the air density in the stratosphere is lower, corresponding to a higher temperature. A measurement of a temperature dependence of the atmospheric ν${}_{\mathrm{\mu <!--\; ??\; -->}}$ flux provides a novel method for constraining hadronic interaction models of air showers. It is particularly sensitive to the production of kaons. Studying this temperature dependence for the first time requires a large sample of high-energy neutrinos as well as a detailed understanding of atmospheric properties. We report the significant (> 10 σ) observation of a correlation between the rate of more than 260,000 neutrinos, detected by IceCube between 2012 and 2018, and atmospheric temperatures of the stratosphere, measured by the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA's AQUA satellite. For the observed 10% seasonal change of effective atmospheric temperature we measure a 3.5(3)% change in the muon neutrino flux. This observed correlation deviates by about 2-3 standard deviations from the expected correlation of 4.3% as obtained from theoretical predictions under the assumption of various hadronic interaction models.

No abstract available

[en] Cobalt zinc ferrite nanoparticles with stoichiometry Co_0.5Zn_0.5Fe₂O₄ (CZFN) were synthesized by sol-gel method with high colloidal stability having room temperature ferromagnetism. For biological applications, CZFN were transferred to aqueous phase by polymer coating with amphiphilic polymer, whereas fluorescent dye (ATTO-590) was used as model system for anti-cancer drug loaded polymer shell. The amount of functional molecule varied up to 25% of the anhydride rings, which provides greater affinity of drug loading in polymer shell. CZFN were characterized by x-ray diffraction, Fourier transformed infrared spectroscopy, UV–vis absorption spectroscopy, gel electrophoresis and vibrating sample magnetometer. The in vitro cytotoxicity of CZFN was examined against HepG₂ which revealed that CZFN (IC₅₀:3.01 nM) strongly inhabits growth of the cells. Further the particles did not induce any significant hemolysis. Stimulatingly, this seems to be a noteworthy improvement towards the ability of surface functionalized multifunctional CZFN as carriers for drugs for anti-cancer therapy and their use as nanomedicine. (paper)

[en] A search for muon neutrinos from neutralino annihilations in the Sun has been performed with the IceCube 22-string neutrino detector using data collected in 104.3 days of live time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured neutralinos in the Sun and converted to limits on the weakly interacting massive particle (WIMP) proton cross sections for WIMP masses in the range 250-5000 GeV. These results are the most stringent limits to date on neutralino annihilation in the Sun.

[en] We report on the first search for atmospheric and for diffuse astrophysical neutrino-induced showers (cascades) in the IceCube detector using 257 days of data collected in the year 2007-2008 with 22 strings active. A total of 14 events with energies above 16 TeV remained after event selections in the diffuse analysis, with an expected total background contribution of 8.3±3.6. At 90% confidence we set an upper limit of E²Φ_90%CL<3.6x10^-7 GeV·cm^-2·s^-1·sr^-1 on the diffuse flux of neutrinos of all flavors in the energy range between 24 TeV and 6.6 PeV assuming that Φ∝E^-2 and the flavor composition of the ν_e ratio ν_μ ratio ν_τ flux is 1 ratio 1 ratio 1 at the Earth. The atmospheric neutrino analysis was optimized for lower energies. A total of 12 events were observed with energies above 5 TeV. The observed number of events is consistent with the expected background, within the uncertainties.