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Number of results: 5
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Abstract

A number of new satellite-only Global Gravity Models (GGMs) become progressively available based on the CHAMP and GRACE satellite mission data. These models promise higher (compared to older GGMs) accuracy in the determination of the low and medium harmonics of the Earth's gravity field. In the present study, the latest GGMs generated from CHAMP and GRACE data (namely EIGEN2, EIGEN3p, GGM0IC, GGM0IS and GRACED IS) have been studied with respect ro their accuracy and performance when used in gravity field approximation. A spectral analysis of the new models has been carried out, employing their degree and error-degree variances. In this way, their performance against each other and with respect to EGM96 was assessed, and the parts of the gravity field spectrum that each model describes more accurately have been identified. The results of the analysis led to the development of a combined geopotential model, complete to degree and order 360, whose coefficients were those of CHAMP until degree 5, then GRACE until degree 116, and EGM96 for the rest of the spectrum. Finally, a validation of all models (the combined included) has been performed by comparing their estimates against GPS/levelling data in land areas and TOPEX/Poseidon sea surface heights in marine regions. All rests have taken place over Greece and the eastern part of the Mediterranean Sea. From the results obtained it was concluded that the combined GGM developed provides more accurate results (compared to EGM96), in terms of the differences with the control datasets, at the level of 1-2 cm geoid and 1-2 mGal for gravity (ICT). Furthermore, the absolute geoid accuracy that the combined GGM offers is 12.9 cm (ICT) for 11 = 120, 25 cm for 11 = 200 and 33 cm for n = 360, compared to 29 cm, 36 cm and 42 cm for EGM96, respectively.
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Authors and Affiliations

Georgios S. Vergos
Ilias N. Tziavos
Michael G. Sideris
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Abstract

The eastern area of Poland is the land of great natural worth both on a country and Europe's scale. This area encompasses the valley of the middle-Bug river that is preserved as the Landscape Park. In this research an attempt was undertaken to assess the heavy metal pollution of the environment in the area of the Landscape Park named ,,The Podlasie Ravine of the Bug River". The level of heavy metals in falling dust, soil, and Dandelion (Taraxacum ojficinale Webb.) was being examined in the five localities, situated in the area of the Park. The research showed that none of the mean permissible standard values of the falling dust, Pb, and Cd were outreached; however, it was observed that the fall of Pb was locally higher in relation to the standard Pb fall values in Janów Podlaski. The concentration level of the elements in the soil equaled the ,,O" degree of heavy metal pollution of the soils. In the circumstances of the reaction soil about pH 6- 7 and low concentrations of the metals in the soil the Cd, Pb elements accumulate in Dandelion in trace quantities. The obtained results indicate that there is no threat whatsoever existing in the shape of the heavy metals in the area of the Landscape Park ,,The Podlasie Ravine of the Bug River".
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Authors and Affiliations

Elżbieta Królak
Grażyna Gołub
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Abstract

One of the applications of tether system is in the field of satellite technology, where the mother ship and satellite equipment are connected with a cable. In order to grasp the motion of this kind of tether system in detail, the tether can be effectively modeled as flexible body and dealt by multibody dynamic analysis. In the analysis and modeling of flexible body of tether, large deformation and large displacement must be considered. Multibody dynamic analysis such as Absolute Nodal Coordinate Formulation with an introduction of the effect of damping force formulation can be used to describe the motion behavior of a flexible body. In this study, a parameter identification technique via an experimental approach is proposed in order to verify the modeling method. An example of swing-up control using the genetic algorithm control approach is performed through simulation and experiment. The validity of the model and availability of motion control based on multibody dynamics analysis are shown by comparison between numerical simulation and experiment.

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Authors and Affiliations

Mohd A. Abdullah
Yohei Michitsuji
Shoichiro Takehara
Masao Nagai
Naoki Miyajima
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Abstract

Im zweiten und dritten Jahrhundert nach Christus hat die Auseinandersetzung mit dem Gnostizismus den Anstoß zur Entwicklung der Kirchentheologie gegeben. Wir können das am Beispiel der Theologie von Iraeneus von Lyon beobachten. Seine Polemik hat zur Präzisierung der Kirchenlehre über den Kanon der Heiligen Schrift, des Begriffes der Tradition und der amtlichen Lehre geführt. Typische Probleme der theologischen Diskussion des zweiten Jahrhunderts, wie etwa die Bedeutung des Alten Testamentes für das Christentum und der Auferstehungsglaube, deutlich polemisch gefasst, wie die Auferstehung des Leibes oder die soteriologische Bedeutung des Todes Jesu, waren die Ergebnisse des Kampfes mit Gnostizismus.

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Authors and Affiliations

Wincenty Myszor
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Abstract

The population structure, seasonal and diel changes in vertical distribution of two siphonophore species, Dimophyes arctica and Pyrostephos vanhoeffeni , in Croker Passage (Antarctic Peninsula) are examined, and compared with the results obtained by other au− thors in various oceanic areas. Zooplankton samples were taken at discrete depth intervals between 0 and 1200 m during day and night shifts, in both summer and winter seasons. Dimophyes arctica was present both in polygastric and eudoxid forms, with the latter being dominant throughout the entire study period. The results obtained demonstrate that Antarctic waters clearly enhance the reproductive ability of this species when compared with specimens from other oceanic regions. Maximum densities of Dimophyes arctica were recorded in December in the 200–400 m depth horizon. However, high concentrations of eudoxids were also recorded at deeper parts of the water column. Pyrostephos vanhoeffeni was, in contrast, most abundant in autumn and winter, and both species were found to proliferate and disperse or sink further down the water column during autumn and winter. Daily vertical migration was observed only during the summer period.
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Authors and Affiliations

Anna A. Panasiuk-Chodnicka
Maria I. Żmijewska
Maciej Mańko

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