Two types of extremely short lasting decimetric bursts and their possible relation to processes in solar magnetic traps

High resolution spectral observations between 500 MHz and 550 MHz on 1972 October 25, revealed an emission event of special interest. The main feature was bursts with a single frequency duration of about 0.09 s and with a bandwidth of the same order of magnitude as the band covered by the spectrograph. The bursts occurred in showers' which lasted for one or two minutes and which were separated by quiet intervals of roughly the same length. Frequently the activity assumed a periodic nature. Periods between 0.1 s and 0.3 s were found. The most remarkable feature of the records was a very large number of bursts with the same duration as the wide band bursts, but showing a bandwidth of a mere 1–2 MHz.The wide band bursts may be plasma waves excited by proton streams trapped in coronal magnetic fields and the narrow band bursts may possibly be explained as perpendicular electrostatic electron cyclotron waves.     

Tides and Arp's hypothesis about distribution of Hii regions

We discuss Arp's hypothesis that the HII regions are more numerous and more conspicuous on the side of a galaxy facing its companion. Arp's hypothesis seems not to be true if we add to Hodge's sets of galaxies only the most probably tidally-interacting cases.     

The statistical effects of galactic tides on the Oort cloud

This report is a comment on two papers by Matese and Whitman (1989, 1992). We discuss here the applicability of uniform probability densities for the orbital parameters of the Oort cloud comets.     

Thermal conduction between an accretion disc and a corona in active galactic nuclei: vertical structure of the transition layer

We study the vertical structure of the transition layer between an accretion disc and a corona in the context of the existence of a two-phase medium in thermally unstable regions. The disc is illuminated by hard X-ray radiation, and satisfies the condition of hydrostatic equilibrium. We take into account the energy exchange between the hot, Compton-heated corona (∼10⁸ K) and cool disc (∼10⁴ K) arising from both radiative processes and thermal conduction. In the case including thermal conduction, we perform a local stability analysis, and conclude that thermal conduction does not suppress thermal instability. In spite of the continuous temperature profile T ( τ ) there are regions of strong temperature gradient, in which spontaneous perturbations can lead to cloud condensation in the transition layer. We determine the minimum size λ _TC of such a perturbation.     

The asymmetry of the velocity distribution in the rotating ring in U Gem stars

It is shown that the non-keplerian character of the rotation of the ring of gas particles in a close binary system gives too large an amplitude of the radial velocity curve if this amplitude is determined from the positions of the emission lines of the ring.     

Solar noise storms coordinated observations: May 16–24, 1981

We present the main results obtained from the coordinated observations of solar radio noise storms organized by C.E.S.R.A. in May 1981. They concern the structure and polarization of radio sources, and the relation with the photospheric magnetic field. A model of coronal magnetic field, accounting for the observations, is briefly discussed.     

Voids in the Jagiellonian Field

This paper presents arguments relating to the phenomenon of scantily populated regions with intergalactic obscuration.     

Extended statistical entropy analysis for the evaluation of nitrogen budgets in Austria

Extended statistical entropy analysis (eSEA) is used to evaluate the nitrogen (N) budgets of two Austrian catchments, the Wulka and the Ybbs, and of entire Austria. The eSEA quantifies the extent of N dispersion in the environment. The results from the eSEA are compared to the corresponding N use efficiencies (NUEs). Application of the eSEA reveals that the Ybbs catchment, compared to the Wulka catchment leads to a greater extent of N dispersion, primarily as a result of increased losses of N compounds to the atmosphere and in leachates to the groundwater. The NUE in the Wulka catchment, at 63 %, is substantially higher than that in the Ybbs catchment, at 43 %, and confirms a more efficient N use in Wulka. Furthermore, it is shown that the adoption of a healthy, balanced diet, as defined by the German Nutrition Society, changes the N budget of Austria in a way that significantly reduces the dispersion of N. Decreased N losses to the atmosphere and to the groundwater are primarily responsible for this result. The national NUE of Austria responds only moderately to the adoption of such a diet increasing from 48 to 53 % and leads to statistically insignificant results if the uncertainty of the input data is taken into account. This study demonstrates the effectiveness of eSEA for the evaluation of N budgets in agricultural regions and suggests that statistical entropy can serve as a reliable agri-environmental indicator to support decisions regarding nutrient management.     

Crustal Stress in the northern North Sea as inferred from borehole breakouts and earthquake focal mechanisms

The regional stress field in the northern North Sea (offshore western Norway) has been studied through the acquisition and analysis of directions of maximum horizontal compression (_H) as extracted from borehole breakouts and from earthquake focal mechanism solutions.
The results indicate that the regional stress field is dominated by NW-SE compression, with good consistency between shallow borehole breakouts (2–5 km depth) and deeper earthquakes (10–25 km depth). The broad spatial consistency in stress direction indicates that the main stress field is related to factors of primarily plate tectonic origin, and the results are in good agreement with the western Europe trend found in earlier investigations.
The Tampen Spur region in the northern North Sea has been subjected to particularly complex deformation, with two dominating fault directions trending NW-SE and NE-SW. From Tampen Spur in the west to the Sogn graben in the east an anomalous stress field is indicated, with NE-SW oriented maximum horizontal compressions. This anomaly is clearly seen both in the borehole breakout data and in the earthquake data. Possible sources for this anomaly are discussed, and include postglacial uplift and/or lateral variations in the physical properties of the crust.