Tensional crack development in physical models with inhomogeneities under load     

Janusz Niewiadomski  Marek Gòrski  Jan Kozák  Reviewer V. Červený  Reviewer J. Javornický 《Studia Geophysica et Geodaetica》1980,24(4):373-381

Summary The paper deals with a study of the mean stress field (_M) and its gradient (_M/x) in uniaxially loaded two-dimensional models of small thickness with respect to other dimensions, in which two inhomogeneities, e.g., a circular opening and a linear slit have been made. Particular attention was paid to the stress field development in the treated models durin gthe change of the mutual geometric configuration of both the inhomogeneities in question. The problem was analysed theoretically by means of Muskhelishvili's potentials of the two-dimensional theory of elasticity. To compare the results of calculations, the schlieren method was used to visualize and record the studied gradients of stress fields in physical models. The results of the calculations were calibrated by laboratory tests. In this way the individual model situations were classified from the point of view of their resistance to the applied load.  相似文献   

Quelques phénomènes accompagnant les phases préliminaires de manifestations éruptives du Vésuve et les relatives possibilités de prévisions     

G. Imbò 《Bulletin of Volcanology》1960,23(1):55-61

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A contribution to the analysis of the altimetry-gravimetry problem     

F. Sacerdote  F. Sansò 《Journal of Geodesy》1983,57(1-4):257-272

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The orthometric height and the holonomity problem     

Fernando Sansò  Petr Vanícek 《Journal of Geodesy》2006,80(5):225-232

When height networks are being adjusted, many geodesists advocate the approach where the adjustment should be done by using geopotential numbers rather than the orthometric or normal heights used in practice. This is based on a conviction that neither orthometric nor normal heights can be used for the adjustment because these height systems are not holonomic, meaning–among other things–that height increments (orthometric or normal) when summed around a closed loop do not sum up to zero. If this was the case, then the two height systems could not be used in the adjustment; the non-zero loop closure would violate the basic, usually unspoken, assumption behind the adjustment, namely that the model claiming that height differences are observable is correct. In this paper, we prove in several different ways that orthometric and normal heights are theoretically just as holonomic as the geopotential numbers are, when they are obtained from levelled height differences using actual gravity values. This disposes of the argument that geopotential numbers should be used in the adjustment. Both orthometric and normal heights are equally qualified to be used in the adjustment directly.  相似文献   

II Hotine-Marussi Symposium on Mathematical Geodesy     

Fernando Sansò 《Journal of Geodesy》1988,62(4):VII-VII

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Book review     

Fernando Sansò  Helmut Moritz 《Journal of Geodesy》1989,63(2):I-II

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Signal and noise in S.L.R. data     

B. Betti  M. Carpino  F. Migliaccio  F. Sansò 《Journal of Geodesy》1987,61(3):235-260

The problem of judging on model deficiency in S.L.R. data treatment is considered. In particular the correlation analysis of residuals of adjusted orbits is used to show the presence of unmodelled signals. This analysis seems suitable at least for a proper preprocessing of S.L.R. data, in the sense of being an efficient procedure of outliers rejection.  相似文献   

Finite covariance functions   总被引：1，自引：0，他引：1  

F. Sansò  W. -D. Schuh 《Journal of Geodesy》1987,61(4):331-347

Because of the full covariance matrices and the computer storage limitations the number of measurements which can be handled by the collocation method simultaneously, is limited. This paper presents a method to compute covariance functions with a finite support yielding sparse covariance matrices. The theoretical background is pointed out and, for the one- and two-dimensional case, special functions are developed which can be combined with the usually used covariance functions to get a “finite covariance function”. Simulated examples to demonstrate the behaviour of different solution methods to solve these special, sparse covariance matrices supplement our investigations.  相似文献   

Further remarks on the altimetry-gravimetry problems     

F. Sacerdote  F. Sansò 《Journal of Geodesy》1987,61(1):65-82

The two Altimetry-Gravimetry linearized boundary value problems, both characterized by gravity anomaly boundary data on the continents, while on the oceans either the gravity potential or its radial derivative is assumed to be known, are investigated in their modified version, in the spherical boundary approximation. A constant unknown bias is added to the data set on the oceans, while a vanishing zerodegree harmonic component is assumed as additional constraint. Existence, uniqueness and regularity results are obtained, it is proved that, in order to obtain regularization of the solution, not only regular data must be imposed, on the continents and on the oceans, but suitable constraints on the coast line are needed.  相似文献   

Physico-chemical Limnology of Lake Naini Tal,Kumaun, Himalaya (U. P.), India     

M. C. Pant  P. C. Sharma  A. P. Sharma 《洁净——土壤、空气、水》1985,13(3):331-350

The monomictic lake at a height of 1937 m, having an area of 48 ha, a mean depth of 16 m and a maximum depth of 27 m, is subjected to such an intensive use in its drainage area that the lake became eutrophicated. The spatial-temporal distribution of important physico-chemical criteria is represented for a period of two years. The depth of visibility varies between 0.4 m (March) and 2 m (June). The thermal stratification keeps up from March to November; therefore in the deep water zone a typical oxygen depletion and an enrichment of PO₄? P (26 μg/l) and of N_inerg (940 μg/l) occur. The pH-value lies in the alkaline range and shows a significantly positive correlation with primary production and temperature and a negative correlation with the carbonate content. Also the oxygen concentration is positively correlated with the primary production and temperature. During stagnation, the sediment/water contact zone is free of oxygen for ca. 70 % of the area.  相似文献