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  • 1
    Electronic Resource
    Electronic Resource
    The planetary scale distribution of telluric currents and the effect of the equatorial electrojet: An investigation by canonical GDS (1987)
    Springer
    Pure and applied geophysics 125 (1987), S. 369-392 
    Details
    ISSN: 1420-9136
    Keywords: Telluric currents ; equatorial electrojet ; GDS ; skim depth ; induction ; oceans
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The planetary scale distribution of electrical currents in the Earth is still largely unknown. The role of the oceans for long period (hours to days) inducing electromagnetic fieldsB e of external origin has been investigated by several authors, while the role of telluric current channelling, from the planetary viewpoint, is still far from a satisfactory understanding. Canonical geomagnetic depth sounding (GDS) analysis can yield locally a direction parallel to the strike of a telluric current density flowing in a region around the recording site and which also has the property of being the most relevant source for the internal origin fieldB i observed at the given site at the given frequency. The use of such local information from 64 geomagnetic observatories is discussed here in a study to infer evidences of (a) the role of the polarization properties ofB e and (b) the role of the telluric current channelling within conductivity anomalies relevant to the planetary scale circuitry. The results show clear evidence of the influence of the equatorial electrojet on the polarization ofB e in a latitudinal band between ±(15°–20°) latitude. There is also evidence that theB e associated with the equatorial electrojet produces telluric currents which flow at a much shallower depth than the skin depth to be expected in the case of a plane Earth. This implies that the Parkinson planes in these regions reflect the conductivity structure underground more than the polarization ofB e due to the equatorial electrojet. Further, it clearly appears that some regular planetary scale pattern of telluric currents plays a more significant role than current channelling within some conductivity anomalies of fixed strike close to some geomagnetic observatories. Finally, the number of observatories used in this study appears to be insufficient to deduce any information concerning a seasonal evolution of the telluric current pattern on a planetary scale.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00874502
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  • 2
    Electronic Resource
    Electronic Resource
    The secular variation of the geomagnetic field and the shape of the Earth
    Amsterdam : Elsevier
    Physics of the Earth and Planetary Interiors 48 (1987), S. 84-114 
    Details
    ISSN: 0031-9201
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0031-9201(87)90114-2
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  • 3
    Electronic Resource
    Electronic Resource
    The hydrostatic equilibrium figure of the Earth: an iterative approach
    Amsterdam : Elsevier
    Physics of the Earth and Planetary Interiors 54 (1989), S. 180-192 
    Details
    ISSN: 0031-9201
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0031-9201(89)90199-4
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  • 4
    Electronic Resource
    Electronic Resource
    A prospective study of the cold response of digital vessels in forestry workers exposed to saw vibration (1998)
    Springer
    International archives of occupational and environmental health 71 (1998), S. 493-498 
    Details
    ISSN: 1432-1246
    Keywords: Key words Cold test ; Follow-up ; Reversibility ; Vibration-induced white finger
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objectives: To investigate the occurrence of vibration-induced white finger (VWF) and the cold response of digital vessels in a group of 68 forestry workers who underwent a first clinical examination in 1990 and were then reexamined in 1995. Methods: The forestry workers were divided into three groups: group A (n = 27), active workers who did not have VWF in␣1990 and continued to use chain saws; group B (n = 29), workers who did not have VWF in 1990 and retired before 1995; and group C (n = 12), active or retired workers who had VWF in 1990. The subjects underwent a medical interview, a complete physical examination, and a cold provocation test, which were performed by the same physicians at both surveys. The cold test consisted of measurement of the finger systolic blood pressure (FSBP) after local cooling to 10 °C, expressed as a percentage of the pressure recorded at 30 °C (FSBP%10°). Results: Three new cases of VWF occurred during the follow-up period among workers who had used only antivibration (AV) chain saws. The vasoconstrictor response to cold was unchanged in group A and improved in group B (P 〈 0.001). A significant decrease in VWF symptoms and abnormal response to cold was observed in group C (P 〈 0.05). As a result of preventive measures curtailing saw usage time in the VWF workers, the daily vibration exposure in group C was lower in 1995 than in 1990 (P = 0.02). In the retired workers, FSBP%10° was positively related to the time since the cessation of work with chain saws (P 〈 0.01). Conclusions: The findings of this follow-up study indicate that a reduction in or cessation of exposure to vibration has a beneficial effect on finger-blanching symptoms and the cold response of digital vessels. The occurrence of new cases of VWF in subjects whose work experience was limited to AV chain saws argues for the maintenance of health surveillance in these workers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004200050311
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  • 5
    Electronic Resource
    Electronic Resource
    Simulation of three-dimensional unsteady viscous free surface flow around a ship model (1994)
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 19 (1994), S. 321-342 
    Details
    ISSN: 0271-2091
    Keywords: Navier-Stokes equations ; Free surface flow ; Finite difference ; Wave resistance ; Frictional resistance ; Adaptive mesh ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: We present here a numerical method for solving the free surface flow around a ship at forward speed in calm water. The fluid is assumed to be Newtonian and the Reynolds-averaged Navier-Stokes equations are solved by a finite difference method. Modelization of turbulence is achieved by the algebraic model proposed by Baldwin and Lomax. Fully non-linear free surface conditions are satisfied in the model and a method to avoid the incompatibility between free surface conditions and no-slip conditions at the waterline is proposed. Numerical results obtained for a Wigley hull are compared with experimental results.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/fld.1650190404
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    Paper (German National Licenses)
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