323 research outputs found
Variations in geomagnetic field elements for the last 4000 years based on paleomagnetic studies of the bottom sediments of lake aslikul (southwestern bashkiria)
The results of the paleomagnetic studies of the bottom sediments of Lake Aslikul have been considered in this work. Bottom sediment cores of thickness of up to 3.0 m have been taken with a special corer, which does not disturb a sample's structure. It has been established that the variations in the declination and inclination of the ChNRM vector, distinguished as a result of cleaning by the alternating magnetic field, are coincident in all three cores studied. The absolute age of the sediments and the time scale in the cores have been I determined by radiocarbon (14C) data. The obtained data made it possible to construct the curves of variation in inclination and declination in this region for the last 4000 years. The obtained results have been preliminarily compared with the records of paleosecular variations in the geomagnetic field elements in Western Europe. It has been found that the curves of declination variation for the last 4000 years in the longitude sector from 1.6° W to 54.7° E correlate well. It has been established that the westward drift of certain inclination features is 0.2-0.13 deg/yr. The anticorrelation in the declination variations, recorded at the westernmost and easternmost points of the studied longitude interval (1.6°W-54.7°E) in the Northern Hemisphere, has also been found. Copyright © 2000 by MAIK "Nauka/Interperiodica"
Aquathermolysis of heavy oil in reservoir conditions with the use of oil-soluble catalysts: part III–changes in composition resins and asphaltenes
© 2018, © 2018 Taylor & Francis Group, LLC. This paper discusses aquathermolysis process of heavy crude oil from Boca de Jaruco reservoir, which is developed by CSS method. The catalysts based on cobalt, nickel, iron and cupper are used to intensify the in-situ conversion processes. The active form of catalysts generates after steam injection. The third part of paper discusses conversion of resins and asphaltenes. The influence of thermo-catalytic conditions and composition of catalysts are also studied. The destruction of resins and asphaltenes are observed after thermocatalytic treatments. The changes in composition of resins and asphaltenes are revealed by IR-spectroscopy data
Natural wavelet transformations of gravity data: Theory and applications
The possibilities of applying a wavelet class to the localization of anomalous gravity field sources are considered. A fast method for constructing density models of geological media on the basis of expansion of gravity anomalies in natural components is proposed. It is shown that, for natural analyzing 1-D and 2-D wavelets, parameters of a point source can be uniquely determined from the coordinates and amplitude of the related wavelet spectrum maximum of the gravity field. A simple method for determining the parameters of arbitrarily distributed point sources from the wavelet spectrum of their total gravity field is developed. Copyright © 2005 by MAIK "Nauka/ Interperiodica" (Russia)
Application of "native" wavelet transform of gravity data for investigation of structure the sedimentary cover and crystalline basement
In this study authors have considered the basic theory and some real-world results of applying the technology of processing gravimetric data based on continuous and discrete wavelet transform with special "native" basic function. The most important result of this study is the technique for determining location and magnitude of the sources of the gravitational field in its wavelet domain for the two and three-dimensional cases. Synthetic examples demonstrate that this problem can be successfully solved for a large number of sources even with significant noise present in the gravimetric data
Cyclical composition of permian rocks
© 2006-2015 Asian Research Publishing Network (ARPN). Permian rocks within Volga-Kama rivers region were considered in light of environments and mechanisms of sedimentary cycles during Middle and Late Permian. Cycles are reconstructed on a lot of lithological data series (grain size, carbonates, magnetic susceptibility) in variations along the sections and in statistical models of spectral analysis. It is mathematically showed that coarse grains parameter is important to reconstruct cyclical composition of section consisted of marine and continental facies. Analysis of cycles on other lithological properties should be carried out in parts of sections with no signs of major breaks and scores
Magnetic properties of the boundary layer at the Cretaceous/Tertiary boundary in the Gams section, Eastern Alps, Austria
The paper is concerned with the detailed sectional petromagnetic study of boundary clay in four 1A, 1B, 2A, and 2B Gams sections (in Austria). The composition of basic magnetic minerals in the boundary clay of all sections is similar. They are composed of iron hydroxides, hemoilmenite, titanomagnetite, magnetite, hematite, and iron. The difference is the presence in the Gams-1 section of metallic nickel, which is absent in the Gams-2 section, and the presence in the latter of iron sulfides of the pyrite type. Grains of titanomagnetite and ilmenite, connected with volcanic activity, are nonuniformly distributed in the boundary layer, which indicates their irregular precipitation in time. The ensemble of magnetic grains is characterized by high coercitivity. The boundary layer is characterized by an increased content of iron hydroxides. This effect is a global phenomenon and is irrelevant to the local physicogeographical conditions. Such a characteristic of impact events as the particles of metallic iron is almost absent in the boundary layer. © Pleiades Publishing, Ltd. 2009
Formal solutions of inverse problem of gravimetry for the spherical data using
In this paper we present a method for interpretation of gravimetric data obtained on spherical surface based on wavelet transform with the so-called "native" wavelet basis. We show that this approach has several distinct advantages over commonly used methods, including a simple way of obtaining formal solutions of the inverse problem and easy identification of the causative sources. The most important result is the technique for determining location and magnitude of the sources of the gravitational fields in its wavelet domain for the two-and three-dimensional cases. We demonstrate The results of the application of wavelet transformation techniques for solving some applied problems for a plane and a sphere
Magnetically responsive calcium carbonate microcrystals
Here we report the fabrication of magnetically responsive calcium carbonate microcrystals produced by coprecipitation of calcium carbonate in the presence of citrate-stabilized iron oxide nanoparticles. We demonstrate that the calcite microcrystals obtained possess superparamagnetic properties due to incorporated magnetite nanoparticles and can be manipulated by an external magnetic field. The microcrystals doped with magnetic nanoparticles were utilized as templates for the fabrication of hollow polyelectrolyte microcapsules, which retain the magnetic properties of the sacrificial cores and might be spatially manipulated using a permanent magnet, thus providing the magnetic-field-facilitated delivery and separation of materials templated on magnetically responsive calcite microcrystals. © 2009 American Chemical Society
Crude oil characterization using TGA-DTA, TGA-FTIR and TGA-MS techniques
© 2016 Elsevier B.V.In this research, combustion characterization and kinetics of four different origin crude oil samples were determined using thermogravimetry - differential thermal analysis (TGA-DTA) and thermogravimetry - Fourier transform infrared (TGA-FTIR) and thermogravimetry – mass spectrophotometry (TGA-MS) techniques. In the TGA-DTA analysis of crude oil samples, low temperature oxidation (LTO) and high temperature oxidation (HTO) reaction regions were observed in different temperature intervals. On the other hand, reaction regions, mass loss, and peak-burnout temperatures of the crude oil samples were also determined using TGA-DTA curves. In TGA-FTIR analysis, spectrums of crude oil samples were examined at different time intervals and composition of several hydrocarbon compounds was determined quantitatively. This research was also focused on the main volatile products (H2, H2O, CO, CO C6H6, SO2 etc…) of different origin crude oil samples on the basis of both their relative intensities and on their relevancy by using TGA-MS technique. Two different Arrhenius types of kinetic models were used in order to determine the kinetic triplets (activation energy, Arrhenius constant and reaction order) of crude oil samples studied. It was observed that in HTO region, higher activation energy values were observed depending on the °API gravities of the crude oils
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