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  • 1
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract During solar flares and coronal mass ejections, nuclei and electrons accelerated to high energies are injected into interplanetary space. These accelerated particles can be detected at the SOHO satellite by the ERNE instrument. From the data produced by the instrument, it is possible to identify the particles and to calculate their energy and direction of propagation. Depending on variable coronal/interplanetary conditions, different kinds of effects on the energetic particle transport can be predicted. The problems of interest include, for example, the effects of particle properties (mass, charge, energy, and propagation direction) on the particle transport, the particle energy changes in the transport process, and the effects the energetic particles have on the solar-wind plasma. The evolution of the distribution function of the energetic particles can be measured with ERNE to a better accuracy than ever before. This gives us the opportunity to contribute significantly to the modeling of interplanetary transport and acceleration. Once the acceleration/transport bias has been removed, the acceleration-site abundance of elements and their isotopes can be studied in detail and compared with spectroscopic observations.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 14 (1996), S. 503-509 
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The HED particle detector of the ERNE experiment to be flown on the SOHO spacecraft is unique compared to the earlier space-born detectors in its high directional resolution (better than 2°, depending on the track inclination). Despite the fixed view cone due to the three-axis stabilization of the spacecraft, the good angular and temporal resolution of the detector provides a new kind of opportunity for monitoring in detail the development of the anisotropies pertaining, for example, to the onset of SEP events, or passage of shock fronts related to gradual events. In order to optimize the measurement parameters, we have made a preflight simulation study of the HED anisotropy measurement capabilities. The purpose was to prove the feasibility of the selected measurement method and find the physical limits for the HED anisotropy detection. The results show HED to be capable of detecting both strong anisotropies related to impulsive events, and smoother anisotropies associated with gradual events.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 16 (1998), S. 921-930 
    ISSN: 0992-7689
    Keywords: Interplanetary physics ; Energetic particles ; Solar physics, astrophysics and astronomy ; Flares and mass ejections
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We consider the prolonged injection of the high-energy (〉 10 MeV) protons during the three successive events observed by GOES in October 1989. We apply a solar-rotation-stereoscopy approach to study the injection of the accelerated particles from the CME-driven interplanetary shock waves in order to find out how the effectiveness of the particle acceleration and/or escape depends on the angular distance from the shock axis. We use an empirical model for the proton injection at the shock and a standard model of the interplanetary transport. The model can reproduce rather well the observed intensity-time profiles of the October 1989 events. The deduced proton injection rate is highest at the nose of the shock; the injection spectrum is always harder near the Sun. The results seem to be consistent with the scheme that the CME-driven interplanetary shock waves accelerate a seed particle population of coronal origin.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Archives of orthopaedic and trauma surgery 118 (1998), S. 89-91 
    ISSN: 1434-3916
    Keywords: Key words Biocompatibility ; Total hip replacement ; Prosthesis coating ; Ceramics ; Silicon carbide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We studied the possible use of silicon carbide (SiC) as a ceramic coating material of titanium-based total hip replacement (THR) implants. The idea is to prevent wear debris formation from the soft titanium surface. SiC is a hard and tightly bonding ceramic surface material, and because of these physical properties it is not easily degradable, as is the case with hydroxyapatite. Our previous in vivo and in vitro studies have indicated that SiC and hydroxyapatite are equally biocompatible regarding particle size for phagocytosis. The present cytotoxicity test using JCRB0603 cells showed that 5 μm SiC particles inhibited colony outgrowth by one-third (67% + 10% vs control), while SiC-coated pins did not cause any inhibition and acted similarly to uncoated titanium pins. The results support the hypothesis that SiC is a promising ceramic THR implant coating material.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 35 (1984), S. 131-134 
    ISSN: 1432-0630
    Keywords: 66.30.Jt ; 61.70.Tm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The diffusion coefficients of aluminium have been measured in polycrystalline fcc Pd and Pt. The Al-implanted palladium and platinum samples were annealed at 400°–800 °C and 450°–900 °C, respectively. The aluminium profiles were probed using the nuclear resonance broadening (NRB) technique. Values of (1.41±0.09) and (1.38±0.09) eV for the activation energy and (1.5 −1.0 +5 )×10−6 and (4 −3 +10 )×10−7cm2/s for the frequency factor were obtained for Al in Pd and Pt, respectively. These anomalous results, compared to the “normal impurity diffusion”, were checked using also Al-evaporated samples.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 35 (1984), S. 227-232 
    ISSN: 1432-0630
    Keywords: 66.30. Jt ; 61.70. Tm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The diffusion of N in the group VI B metals Cr and W has been studied in the previously uninvestigated temperature ranges 300°–550 °C (Cr) and 600°–800 °C (W) using ion-beam techniques. Diffusion couples were created by ion-implantation. The timedependent diffusion profiles were monitored by the use of the Nuclear Resonance Broadening (NRB) technique. The linear Arrhenius plots extracted from the measured diffusivities indicate that the diffusivity of implanted N in Cr and W can be described by the activation energyQ=1.39±0.06 eV and 2.32±0.16 eV and the pre-exponential factorD 0=(7.0±7.2)×10−4cm2/s and 4.3±8.3cm2/s, respectively. The solubilities of N in Cr and W from the implanted distributions were found to deviate from those obtained using conventional metallographical methods.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 34 (1984), S. 49-56 
    ISSN: 1432-0630
    Keywords: 66.30. Jt ; 61.70. Tm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The diffusion of N in the group VB metals V and Nb has been studied in the previously uninvestigated temperature range 300–500 °C using ion-beam techniques. Diffusion couples were created by ion implantation. The time-dependent diffusion profiles were monitored by the use of the Nuclear Resonance Broadening (NRB) technique. New values for the solubility of N in Nb were obtained. The diffusion rates presented support recent observations of the diffusivity of interstitial impurities in body-centered cubic metals in which positive deviations from Arrhenius behaviour have been seen at high temperatures.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-0630
    Keywords: 81.15 ; 81.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The carbon plasma ion energies produced by the pulsed filtered arc-discharge method have been measured as a function of the anode-cathode voltage. The energies were determined by using the electro-optical time-of-flight method. The highest anode-cathode voltage was 5 kV and yielded the energy of 140 eV for the plasma ions. In addition, it was demonstrated that a rather slight change of the parameters in the arc-discharge method has a strong effect on the plasma ion energies and the properties of the diamond-like coatings prepared.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-0630
    Keywords: PACS: 81.15; 81.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract.  The carbon plasma ion energies produced by the pulsed filtered arc-discharge method have been measured as a function of the anode–cathode voltage. The energies were determined by using the electro-optical time-of-flight method. The highest anode–cathode voltage was 4 kV and yielded the energy of 140 eV for the plasma ions. In addition, it was demonstrated that a rather slight change of the parameters in the arc-discharge method has a strong effect on the plasma ion energies and the properties of the diamond-like coatings prepared.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A solar energetic particle event was observed on 9 July 1996, by the ERNE sensors LED and HED on board the SOHO spacecraft. The arrival of the first protons in the energy range 〉20 MeV took place at 09:55 UT, 43 min after the maximum in the X-ray and Hα radiation of a flare located at S10 W30. The rise phase of the particle intensities at all energies was exceptionally rapid. At 12:50 UT, the intensities dropped in all energy channels. Simultaneously, the magnetic field instrument MFI on board WIND, not far from SOHO, detected a sharp and large change in the magnetic field direction. The analysis of the directional measurements of ERNE in the energy range 14–17 MeV shows the presence of a strong flux anisotropy during the whole period 10:10–12:50 UT. From 12:50 UT until about 16:00 UT, the directional analysis of the proton fluxes gives only a weak anisotropy at the limit of the sensor resolution. Later on, the flux anisotropy was found to recur, indicating a continuous injection of particles into the flux tubes connected to the SOHO spacecraft. These experimental results lead to strict limits on particle injection and transport models. The first period of the anisotropy and its recurrent phase cover 24 hours. This suggests an extended injection of particles. The strength and stability of the anisotropy indicate that, during these periods, SOHO was in an interplanetary sector where the particle transport was almost scatter-free. On the other hand, during the intermediate 3-hr period, we observed particles which traveled in a sector of diffusive transport or which were retarded by magnetic field disturbances not far from the observation site.
    Type of Medium: Electronic Resource
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