2,214 research outputs found

    Internet as source of competitive advantage: a case in the port industry

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    A Internet tem sido reconhecida como uma fonte de vantagem competitiva. Em países emergentes, como o Brasil, a Internet representa novas possibilidades para empresas e para inserção da economia nacional em mercados globais. A presente pesquisa objetiva entender como uma empresa atuando no setor portuário no Brasil pode obter vantagens competitivas através de aplicações baseadas em Internet. Para isto, algumas questões devem ser respondidas: (i) Como uma empresa brasileira pode usar aplicações baseadas em Internet para estabelecer diferenciais frente à concorrência no setor portuário? (ii) Como as características do cenário brasileiro - instabilidade econômica, legislação, impostos, mão-de-obra, criatividade - afetaram as estratégias de aplicações on-line baseadas em Internet dessa empresa? Para tanto, foram utilizados diversos elementos presentes na bibliografia sobre estratégia e tecnologia da informação. O método aplicado foi o estudo de caso, realizado em um terminal de contêineres do Porto de Santos que tem usado intensamente a Internet em suas operações.Internet has been acknowledged as a source of competitive advantage. For development countries as Brazil, the Net can bring new possibilities for companies and for national economy insertion in global markets. For this reason, Internet strategic use was analysed in a Brazilian Port. This research aims to understand how a company of the ports industry in Brazil can obtain competitive advantages through Internet-based applications. For this purpose, the following questions should be answered: (i) How a Brazilian company can use Internet-based applications to establish differentials from its competitors in ports industry?(ii) How the characteristics of the Brazilian environment like economic instability, laws, taxes, workforce, creativity biased on-line strategies of this company? In order to clarify these points, concepts about strategy and information technology were analysed. The applied method was case study, performed in a container terminal in the Brazilian Port in Santos, which had used Internet intensively in its operations

    II Diretriz Brasileira de Transplante Cardíaco

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    Universidade de São Paulo Faculdade de Medicina Hospital das ClínicasIIHospital de Messejana Dr. Carlos Alberto Studart GomesUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaInstituto Dante Pazzanese de CardiologiaUniversidade Federal de Minas Gerais Hospital das ClínicasFaculdade de Medicina de São José do Rio PretoPontifícia Universidade Católica do ParanáIHospital Israelita Albert EinsteinInstituto Nacional de Cardiologia, Fundação Universitária do Rio Grande do Sul Instituto de CardiologiaReal e Benemérita Sociedade de Beneficência Portuguesa, São PauloHospital Pró-Cardíaco do Rio de JaneiroSanta Casa do Rio de JaneiroUNIFESP, EPMSciEL

    Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

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    In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data

    Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

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    The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle

    Measuring the muon content of inclined air showers using AERA and the water-Cherenkov detector array of the Pierre Auger Observatory

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    Investigating multiple elves and halos above strong lightning with the fluorescence detectors of the Pierre Auger Observatory

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    ELVES are being studied since 2013 with the twenty-four FD Telescopes of the Pierre Auger Observatory, in the province of Mendoza (Argentina), the world’s largest facility for the study of ultra-high energy cosmic rays. This study exploits a dedicated trigger and extended readout. Since December 2020, this trigger has been extended to the three High levation Auger Telescopes (HEAT), which observe the night sky at elevation angles between 30 and 60 degrees, allowing a study of ELVES from closer lightning. The high time resolution of the Auger telescopes allows us to upgrade reconstruction algorithms and to do detailed studies on multiple ELVES. The origin of multiple elves can be studied by analyzing the time difference and the amplitude ratio between flashes and comparing them with the properties of radio signals detected by the ENTLN lightning network since 2018. A fraction of multi-ELVES can also be interpreted as halos following ELVES. Halos are disc-shaped light transients emitted at 70-80 km altitudes, appearing at the center of the ELVES rings, due to the rearrangement of electric charges at the base of the ionosphere after a strong lightning event

    Status and expected performance of the AugerPrime Radio Detector

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    The second knee in the cosmic ray spectrum observed with the surface detector of the Pierre Auger Observatory

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    The dynamic range of the upgraded surface-detector stations of AugerPrime

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    The detection of ultra-high-energy cosmic rays by means of giant detector arrays is often limited by the saturation of the recorded signals near the impact point of the shower core at the ground, where the particle density dramatically increases. The saturation affects in particular the highest energy events, worsening the systematic uncertainties in the reconstruction of the shower characteristics. The upgrade of the Pierre Auger Observatory, called AugerPrime, includes the installation of an 1-inch Small PhotoMultiplier Tube (SPMT) inside each water-Cherenkov station (WCD) of the surface detector array. The SPMT allows an unambiguous measurement of signals down to about 250m from the shower core, thus reducing the number of events featuring a saturated station to a negligible level. In addition, a 3.8m2 plastic scintillator (Scintillator Surface Detector, SSD) is installed on top of each WCD. The SSD is designed to match the WCD (with SPMT) dynamic range, providing a complementary measurement of the shower components up to the highest energies. In this work, the design and performances of the upgraded AugerPrime surface-detector stations in the extended dynamic range are described, highlighting the accuracy of the measurements. A first analysis employing the unsaturated signals in the event reconstruction is also presented

    Combined fit to the spectrum and composition data measured by the Pierre Auger Observatory including magnetic horizon effects

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    The measurements by the Pierre Auger Observatory of the energy spectrum and mass composition of cosmic rays can be interpreted assuming the presence of two extragalactic source populations, one dominating the flux at energies above a few EeV and the other below. To fit the data ignoring magnetic field effects, the high-energy population needs to accelerate a mixture of nuclei with very hard spectra, at odds with the approximate E2^{-2} shape expected from diffusive shock acceleration. The presence of turbulent extragalactic magnetic fields in the region between the closest sources and the Earth can significantly modify the observed CR spectrum with respect to that emitted by the sources, reducing the flux of low-rigidity particles that reach the Earth. We here take into account this magnetic horizon effect in the combined fit of the spectrum and shower depth distributions, exploring the possibility that a spectrum for the high-energy population sources with a shape closer to E2^{-2} be able to explain the observations
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