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  • 1
    Electronic Resource
    Electronic Resource
    Coronal holes and solar magnetic fields (1979)
    Springer
    Space science reviews 23 (1979), S. 139-158 
    Details
    ISSN: 1572-9672
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Since 1972, nearly continuous observations of coronal holes and their associated photospheric magnetic fields have been made using a variety of satellite and ground-based equipment. The results of comparisons of these observations are reviewed and it is demonstrated that the structure and evolution of coronal holes is basically governed by the large-scale distribution of photospheric magnetic flux. Non-polar holes form in the decaying remnants of bipolar magnetic regions in areas with a large-scale flux imbalance. There is strong indirect evidence that the magnetic field in coronal holes is always open to interplanetary space but not all open-field regions have associated coronal holes. The well-observed declining phase of the last solar cycle was characterized by stable magnetic field and coronal hole patterns which were associated with recurrent, high-speed wind streams and interplanetary magnetic field patterns at the Earth. The ascending phase of the current cycle has been characterized by transient magnetic field and coronal hole patterns which tend to occur at high solar latitudes. This shift in magnetic field and coronal hole patterns has resulted in a less obvious and more complicated association with high-speed wind streams at the Earth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00173808
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  • 2
    Electronic Resource
    Electronic Resource
    Dynamics of the preflare magnetic field (1983)
    Springer
    Space science reviews 34 (1983), S. 55-62 
    Details
    ISSN: 1572-9672
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Many theories of the solar flare process invoke storage of energy in the active region magnetic field above the solar photosphere. Observational evidence relating to such storage is rather unsatisfactory owing to our inability to observe the three-dimensional structure of the magnetic field. Indirect evidence comes from changes in structures presumed to trace the magnetic field, from changes in the line-of-sight and transverse components of the photospheric magnetic field, from mass flow patterns observed by proper motions and line-of-sight Doppler shifts, and from radio observations. These data tend to confirm that energy sufficient to produce flares can be stored in active region magnetic fields with a characteristic time scale of hours but critical observation are not yet available.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221196
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  • 3
    Electronic Resource
    Electronic Resource
    The NASA/NSO Spectromagnetograph (1992)
    Springer
    Solar physics 139 (1992), S. 211-232 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The NASA/NSO Spectromagnetograph is a new focal plane instrument for the National Solar Observatory/Kitt Peak Vacuum Telescope which features real-time digital analysis of long-slit spectra formed on a two-dimensional CCD detector. The instrument is placed at an exit port of a Littrow spectrograph and uses an existing modulator of circular polarization. The new instrument replaces the 512-channel Diode Array Magnetograph first used in 1973. Commercial video processing boards are used to digitize the spectral images at video rates and to separate, accumulate, and buffer the spectra in the two polarization states. An attached processor removes fixed-pattern bias and gain from the spectra in cadence with spatial scanning of the image across the entrance slit. The data control computer performs position and width analysis of the line profiles as they are acquired and records line-of-sight magnetic field, Doppler shift, and other computed parameters. The observer controls the instrument through windowed processes on a data control console using a keyboard and mouse. Early observations made with the spectromagnetograph are presented and plans for future development are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00159149
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  • 4
    Electronic Resource
    Electronic Resource
    Estimation Of Seeing Quality Using Low-Resolution Solar Image Data (1999)
    Springer
    Solar physics 185 (1999), S. 15-34 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Modulation transfer functions (MTFs), generated as a by-product of the analysis of low-resolution solar images taken for the Global Oscillation Network Group, were used to estimate the quality of seeing at its six sites. These MTFs, after approximate correction for the effects of the instrumental point spread function, were fitted with physically-motived functional forms representing the effects of seeing and scattering. It was found that the estimates of seeing quality were relatively robust to the effects of scattering, but were severely biased by effects caused by changes in instrumental focus. Relative trends in seeing quality are preserved on time scales shorter than a few months and it is found that local topography dominates the observed trends in daytime seeing quality.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1005113912734
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  • 5
    Electronic Resource
    Electronic Resource
    A comparison of EUV spectroheliograms and photospheric magnetograms (1974)
    Springer
    Solar physics 34 (1974), S. 105-111 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A comparison of EUV data from the Harvard College Observatory experiment on OSO-6 with photospheric magnetograms from Kitt Peak National Observatory indicates a bipartite relationship between values of the longitudinal field strength B and Mg x intensity I averaged over square areas 35″ × 35″: in quiet regions ¦B¦ ∼ I k, where 0.0 ≲ k ≲ 0.3, and in active regions ¦B¦ ∼ I. From these relationships we infer that ¦B¦ ∼ n e 2k in quiet regions and ¦B¦ ∼ n e 2 in active regions. In addition, the photospheric field beneath a coronal hole is found to be virtually identical to that beneath normal quiet regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00149602
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  • 6
    Electronic Resource
    Electronic Resource
    Recent observations of high-degree solar p-mode oscillations at the Kitt Peak National Observatory (1983)
    Springer
    Solar physics 82 (1983), S. 111-111 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A brief summary is given of a program which is currently being carried out with the McMath telescope of the Kitt Peak National Observatory in order to study high-degree (l ≳ 150) solar p-mode oscillations. This program uses a 244 × 248 pixel CID camera and the main spectrograph of the McMath telescope to obtain velocity-time maps of the oscillations which can be converted into two-dimensional (k h - ω) power spectra of the oscillations. Several different regions of the solar spectrum have been used in order to study the oscillations at different elevations in the solar atmosphere. The program concentrates on eastward- and westward-propagating sectoral harmonic waves so that measurements can be made of the absolute rotational velocities of the solar photospheric and shallow sub-photospheric layers. Some preliminary results from this program are now available. First, we have been unable to confirm the existence of a radial gradient in the equatorial rotational velocity as was previously suggested. Second, we have indeed been able to confirm the presence of p-mode waves in the solar chromosphere as was first suggested by Rhodes et al. (1977). Third, we have been able to demonstrate differences in photospheric and chromospheric power spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00145550
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  • 7
    Electronic Resource
    Electronic Resource
    Glucose metabolism of mammalian erythrocytesSupported in part by a Public Health Training Grant (GM-633) from the National Institute of General Medical Sciences. (1976)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 89 (1976), S. 219-223 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Under physiological conditions, erythrocytes of the horse metabolized 638 ± 37 (± SE) nmoles glucose/ml cells/hr at 37°C compared to 942 ± 31 for the cat, 1,329 ± 44 for the dog, and 1,485 ± 43 for man. On an absolute basis, pentose phosphate metabolism was similar between species, with species differences in erythrocyte glucose utilization attributable to differences in Embden-Meyerhof pathway metabolism. By examining pentose phosphate pathway recycling, it appears that some functional compartmentation exists within erythrocytes.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040890205
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  • 8
    Electronic Resource
    Electronic Resource
    Smooth interfacing of finite element models (1979)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 14 (1979), S. 1073-1078 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: A technique for smoothing the transition between structural components modelled with dissimilar finite element meshes is presented. The interface mismatch is assigned a potential of dislocation, which is minimized with respect to selected kinematic parametes of the mating surface. This leads to linear constraints between the caididate representations of the mating surface which essentially dictate a least-square error in dislocaiton. The constraints are enforced by the Lagrange multiplier or reduced stiffness technique. Numerical results indicate gradual transition in the predicted stresses neighbouring the interface. Existing computer codes which permit multipoint constraint specifications are readily available to implement the technique.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620140710
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  • 9
    Electronic Resource
    Electronic Resource
    Dual analysis of plane stress problems by commonly based finite elements (1983)
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 19 (1983), S. 971-984 
    Details
    ISSN: 0029-5981
    Keywords: Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mathematics , Technology
    Notes: Finite element models for linear elastic plane stress problems which provide, alternatively, a completely compatible displacement field or a precisely equilibrated stress field are developed. The basis for both models is a biquintic interpolation polynomial representing Airy's stress function over a triangular region. The polynomial coefficients are modified and grouped to establish compatibility while retaining equilibrium within each element. Nodal kinematic parameters are selected and matched to the stress function for the compatible (modified stiffness) model, while nodal stress function parameters are chosen for the equilibrium (modified flexibility) model. Constraints on the global freedoms, enforced by Lagrange multipliers, are introduced to augment nodal connectivity in establishing interelement compatibility in the ‘stiffness’ model and uniform stress transmission in the ‘flexibility’ model. Appropriate boundary conditions are formed for each model. Numerical solutions are obtained and assessed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/nme.1620190703
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  • 10
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    A comparison of EUV spectroheliograms and photospheric magnetograms (1974)
    Springer
    Details
    Publication Date: 1974-01-01
    Print ISSN: 0038-0938
    Electronic ISSN: 1573-093X
    Topics: Physics
    Published by Springer
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