130 research outputs found

    On elliptic solutions of the quintic complex one-dimensional Ginzburg-Landau equation

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    The Conte-Musette method has been modified for the search of only elliptic solutions to systems of differential equations. A key idea of this a priory restriction is to simplify calculations by means of the use of a few Laurent series solutions instead of one and the use of the residue theorem. The application of our approach to the quintic complex one-dimensional Ginzburg-Landau equation (CGLE5) allows to find elliptic solutions in the wave form. We also find restrictions on coefficients, which are necessary conditions for the existence of elliptic solutions for the CGLE5. Using the investigation of the CGLE5 as an example, we demonstrate that to find elliptic solutions the analysis of a system of differential equations is more preferable than the analysis of the equivalent single differential equation.Comment: LaTeX, 21 page

    Microstructure and biodegradation performance of Mg–4Ca–1Zn based alloys after ultrasonic treatment and doping with nanodiamonds for biomedical applications

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    This work aims to study microstructural features, phase composition, topology, surface potential, and the biodegradation performance of Mg–4Zn–1Ca-based alloys whose melts were ultrasonically (US) treated and doped with nanodiamonds (ND). The findings show a correlation between the ratio of the secondary phase segregated along the grain boundaries and the biodegradation rate in the RPMI-1640 synthetic culture medium. The fewer Ca2Mg6Zn3 phase fraction, the lower the biodegradation rate. Also, ND doping does not significantly affect the biodegradation rate. Intriguingly, the latter in the US-treated alloy was found to be noticeably inhibited due to a smoother topography and the presence of the fewest Ca2Mg6Zn3 phase fraction segregated along the grain boundaries. Further studies are needed to assess the biodegradable potential of the ND doped alloy, which melt was ultrasonically treated

    Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method

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    This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known e/he/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within ±1\pm 1% of the true values and the fractional energy resolution is [(58±3)/E+(2.5±0.3)[(58\pm3)% /\sqrt{E}+(2.5\pm0.3)%]\oplus (1.7\pm0.2)/E. The value of the e/he/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74±0.041.74\pm0.04 and agrees with the prediction that e/h>1.7e/h > 1.7 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM

    Results from a combined test of an electromagnetic liquid argon calorimeter with a hadronic scintillating-tile calorimeter

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    The first combined test of an electromagnetic liquid argon accordion calorimeter and a hadronic scintillating-tile calorimeter was carried out at the CERN SPS. These devices are prototypes of the barrel calorimeter of the future ATLAS experiment at the LHC. The energy resolution of pions in the energy range from 20 to 300~GeV at an incident angle θ\theta of about 11^\circ is well-described by the expression \sigma/E = ((46.5 \pm 6.0)\%/\sqrt{E} +(1.2 \pm 0.3)\%) \oplus (3.2 \pm 0.4)~\mbox{GeV}/E. Shower profiles, shower leakage, and the angular resolution of hadronic showers were also studied

    Evaluation of Fermi Read-out of the ATLAS Tilecal Prototype

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    Prototypes of the \fermi{} system have been used to read out a prototype of the \atlas{} hadron calorimeter in a beam test at the CERN SPS. The \fermi{} read-out system, using a compressor and a 40 MHz sampling ADC, is compared to a standard charge integrating read-out by measuring the energy resolution of the calorimeter separately with the two systems on the same events. Signal processing techniques have been designed to optimize the treatment of \fermi{} data. The resulting energy resolution is better than the one obtained with the standard read-out

    Response of the ATLAS tile calorimeter prototype to muons

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    A study of high energy muons traversing the ATLAS hadron Tile calorimeter in the barrel region in the energy range between 10 and 300~GeV is presented. Both test beam experimental data and Monte Carlo simulations are given and show good agreement. The Tile calorimeter capability of detecting isolated muons over the above energy range is demonstrated. A signal to background ratio of about 10 is expected for the nominal LHC luminosity (1034cm2sec110^{34} cm^{-2} sec^{-1}). The photoelectron statistics effect in the muon shape response is shown. The e/mip ratio is found to be 0.81±0.03 0.81 \pm 0.03; the e/μ\mu ratio is in the range 0.91 - 0.97. The energy loss of a muon in the calorimeter, dominated by the energy lost in the absorber, can be correlated to the energy loss in the active material. This correlation allows one to correct on an event by event basis the muon energy loss in the calorimeter and therefore reduce the low energy tails in the muon momentum distribution

    A measurement of the energy loss spectrum of 150 GeV muons in iron

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    The energy loss spectrum of 150 GeV muons has been measured with a prototype of the ATLAS hadron calorimeter in the H8 beam of the CERN SPS.\\ The differential probability dP/dvdP/dv per radiation length of a fractional energy loss v=ΔEμ/Eμv = \Delta E_{\mu} / E_{\mu} has been measured in the range v=0.01÷0.95v = 0.01 \div 0.95 ; it is then compared with the theoretical predictions for energy losses due to bremsstrahlung and production of electron-positron pairs or of energetic knock-on electrons.\\ The integrated probability 0.010.95(dP/dv)dv\int_{0.01}^{0.95} (dP/dv) dv is (1.610±0.015stat.±0.105syst.)103(1.610\pm0.015_{stat.}\pm0.105_{syst.})\cdot10^{-3} in agreement with the theoretical predictions of 1.5561031.556\cdot10^{-3} and 1.6191031.619\cdot10^{-3}. %7.8.96 - start Agreement with theory is also found in two intervals of vv where production of electron-positron pairs and knock-on electrons dominates. In the region of bremsstrahlung dominance (v=0.12÷0.95v = 0.12\div0.95) the measured integrated probability (1.160±0.040stat±0.075syst)104(1.160\pm0.040_{stat}\pm0.075_{syst})\cdot 10^{-4} is in agreement with the theoretical value of 1.1851041.185 \cdot 10^{-4} , obtained using Petrukhin and Shestakov's \cite{PS} description of the bremsstrahlung process. The same result is about 3.6 standard deviations (defined as the quadratic sum of statistical and systematic errors) lower than the theoretical prediction of 1.472104 1.472\cdot 10^{-4}, obtained using Tsai's \cite{TS} description of bremsstrahlung

    Thermal-Chemical Characteristics of Al-Cu Alloy Nanoparticles

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    This work investigated the oxidation, ignition, and thermal reactivity of alloy nanoparticles of aluminum and copper (nAlCu) using simultaneous thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) method. The microstructure of the particles was characterized with a scanning electron microscope (SEM) and transmission electron microscope (TEM), and the elemental composition of the particles before and after the oxidation was investigated with energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The particles were heated from room temperature to 1200 °C under different heating rates from 2 to 30 K/min in the presence of air. The complete oxidation process of the nAlCu was characterized by two exothermic and two endothermic reactions, and the reaction paths up to 1200 °C were proposed. An early ignition of nAlCu, in the temperature around 565 °C, was found at heating rates ≥ 8 K/min. The eutectic melting temperature of nAlCu was identified at ∼546 °C, which played a critical role in the early ignition. The comparison of the reactivity with that of pure Al nanoparticles showed that the nAlCu was more reactive through alloying

    ATLAS detector and physics performance: Technical Design Report, 1

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    Design of Normal-conducting Quadrupole Magnets for Linac4 at CERN

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    Linac4 is the first element of the LHC Injectors Upgrade Project and will replace the existing Linac2 as linear injector of protons for the CERN accelerators. A new transfer line will link Linac4 to the Proton Synchrotron Booster (PSB). Approximately hundred normal-conducting electro-magnets are required for beam steering and focusing along the linac and the transfer line. This text concentrates on the design of the Linac4 quadrupole magnets. The design and the first magnetic measurements of the inter-tank quadrupole electro-magnets are discussed. In addition, the design and optimization of the transfer line quadrupole magnets are highlighted. The compatibility of the magnetic requirements and the power converter constraints for the latter magnet type is assessed
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