On Increasing of Resolution of Satellite Images via Their Fusion with Imagery at Higher Resolution

In this paper we propose a new statement of the spatial increasing resolution problem of MODIS-like multi-spectral images via their fusion with Lansat-like imagery at higher resolution. We give a precise definition of the solution to the indicated problem, postulate assumptions that we impose at the initial data, establish existence and uniqueness result, and derive the corresponding necessary optimality conditions. For illustration, we supply the proposed approach by results of numerical simulations with real-life satellite images.In this paper we propose a new statement of the spatial increasing resolution problem of MODIS-like multi-spectral images via their fusion with Lansat-like imagery at higher resolution. We give a precise definition of the solution to the indicated problem, postulate assumptions that we impose at the initial data, establish existence and uniqueness result, and derive the corresponding necessary optimality conditions. For illustration, we supply the proposed approach by results of numerical simulations with real-life satellite images

Dolomite-IV : Candidate structure for a carbonate in the Earth's lower mantle

We report the crystal structure of dolomite-IV, a high-pressure polymorph of Fe-dolomite stabilized at 115 GPa and 2500 K. It is orthorhombic, space group Pnma, a =10.091(3), b = 8.090(7), c = 4.533(3) Å, V = 370.1(4) Å3 at 115.2 GPa and ambient temperature. The structure is based on the presence of threefold C3O9 carbonate rings, with carbon in tetrahedral coordination. The starting Fe-dolomite single crystal during compression up to 115 GPa transforms into dolomite-II (at 17 GPa) and dolomite-IIIb (at 36 GPa). The dolomite-IIIb, observed in this study, is rhombohedral, space group R3, a =11.956(3), c =13.626(5) Å, V =1686.9(5) Å3 at 39.4 GPa. It is different from a previously determined dolomite-III structure, but topologically similar. The density increase from dolomite-IIIb to dolomite IV is ca. 3%. The structure of dolomite-IV has not been predicted, but it presents similarities with the structural models proposed for the high-pressure polymorphs of magnesite, MgCO3. A ring-carbonate structure match with spectroscopic analysis of high-pressure forms of magnesite-siderite reported in the literature, and, therefore, is a likely candidate structure for a carbonate at the bottom of the Earth's mantle, at least for magnesitic and dolomitic compositions

Dolomite-IV : Candidate structure for a carbonate in the Earth's lower mantle

We report the crystal structure of dolomite-IV, a high-pressure polymorph of Fe-dolomite stabilized at 115 GPa and 2500 K. It is orthorhombic, space group Pnma, a =10.091(3), b = 8.090(7), c = 4.533(3) \uc5, V = 370.1(4) \uc53 at 115.2 GPa and ambient temperature. The structure is based on the presence of threefold C3O9 carbonate rings, with carbon in tetrahedral coordination. The starting Fe-dolomite single crystal during compression up to 115 GPa transforms into dolomite-II (at 17 GPa) and dolomite-IIIb (at 36 GPa). The dolomite-IIIb, observed in this study, is rhombohedral, space group R3, a =11.956(3), c =13.626(5) \uc5, V =1686.9(5) \uc53 at 39.4 GPa. It is different from a previously determined dolomite-III structure, but topologically similar. The density increase from dolomite-IIIb to dolomite IV is ca. 3%. The structure of dolomite-IV has not been predicted, but it presents similarities with the structural models proposed for the high-pressure polymorphs of magnesite, MgCO3. A ring-carbonate structure match with spectroscopic analysis of high-pressure forms of magnesite-siderite reported in the literature, and, therefore, is a likely candidate structure for a carbonate at the bottom of the Earth's mantle, at least for magnesitic and dolomitic compositions

Pressure tuning of charge ordering in iron oxide

A Verwey-type charge-ordering transition in magnetite at 120 K leads to the formation of linear units of three iron ions with one shared electron, called trimerons. The recently-discovered iron pentoxide (Fe$_4$O$_5$) comprising mixed-valent iron cations at octahedral chains, demonstrates another unusual charge-ordering transition at 150 K involving competing formation of iron trimerons and dimerons. Here, we experimentally show that applied pressure can tune the charge-ordering pattern in Fe$_4$O$_5$ and strongly affect the ordering temperature. We report two charge-ordered phases, the first of which may comprise both dimeron and trimeron units, whereas, the second exhibits an overall dimerization involving both the octahedral and trigonal-prismatic chains of iron in the crystal structure. We link the dramatic change in the charge-ordering pattern in the second phase to redistribution of electrons between the octahedral and prismatic iron chains, and propose that the average oxidation state of the iron cations can pre-determine a charge-ordering pattern

До питання про вплив напруги в елементах армування стволів на швидкість їх корозії

On the basis of laboratory explorations the features of conducting the corrosive process in the shaft reinforcement parts under the load from lifting buckets and rock mass were determined.На базе лабораторных исследований установлены особенности протекания процесса коррозии элементов армировки, находящихся под нагрузкой от подъемных сосудов и со стороны породного массива.На базі лабораторних досліджень встановлено особливості процесу корозії елементів армування, що знаходяться під навантаженням від підйомних судин та з боку породного масиву

TO THE QUESTION ABOUT THE INFLUENCE OF THE STRESSES IN THE ELEMENTS OF THE REINFORCEMENT SHAFTS AT THE RATE OF CORROSION

On the basis of laboratory explorations the features of conducting the corrosive process in the shaft reinforcement parts under the load from lifting buckets and rock mass were determined

The influence of solid solution on elastic wave velocity determination in (Mg,Fe)O using nuclear inelastic scattering

Elastic wave velocities of minerals are important for constraining the chemistry, structure and dynamics of the Earth’s mantle based on the comparison between laboratory-based measurements and seismic observations. As the second most abundant phase in the Earth’s lower mantle, (Mg,Fe)O ferropericlase has been the focus of numerous studies measuring the elastic wave velocities using various methods such as Brillouin spectroscopy and ultrasonic measurements. Recently, nuclear inelastic scattering (NIS) has been used to determine elastic wave velocities of iron-bearing phases. However, the elastic wave velocities of ferropericlase obtained using NIS are considerably lower than the velocities obtained by other methods, even at ambient conditions. One possible source of this discrepancy is the local nature of the NIS method. In order to test this hypothesis, we have investigated six ferropericlase samples with various iron contents using NIS. The Debye sound velocities calculated using the conventional method of NIS analysis are consistent with previous results obtained using NIS, yet the values are significantly lower than those obtained using ultrasonics and Brillouin spectroscopy. If the Debye sound velocities are re-calculated based on a mixture of different iron next-neighbour configurations with different compositions, the Debye sound velocities determined by NIS agree well with the results from other methods. Our new model was also successfully applied to high-pressure NIS data taken from the literature. Our results constitute an important step towards a better understanding of how to obtain reliable sound velocities of iron-bearing mantle minerals from NIS measurements

Sound velocities of skiagite–iron–majorite solid solution to 56 GPa probed by nuclear inelastic scattering

High-pressure experimental data on sound velocities of garnets are used for interpretation of seismological data related to the Earth’s upper mantle and the mantle transition zone. We have carried out a Nuclear Inelastic Scattering study of iron-silicate garnet with skiagite (77 mol%)–iron–majorite composition in a diamond anvil cell up to 56 GPa at room temperature. The determined sound velocities are considerably lower than sound velocities of a number of silicate garnet end-members, such as grossular, pyrope, Mg–majorite, andradite, and almandine. The obtained sound velocities have the following pressure dependencies: $V_p$ [km/s] = 7.43(9) + 0.039(4) × P [GPa] and $V_s$ [km/s] = 3.56(12) + 0.012(6) × P [GPa]. We estimated sound velocities of pure skiagite and khoharite, and conclude that the presence of the iron–majorite component in skiagite strongly decreases $V_s$ . We analysed the influence of Fe$^{3+}$ on sound velocities of garnet solid solution relevant to the mantle transition zone and consider that it may reduce sound velocities up to 1% relative to compositions with only Fe$^{2+}$ in the cubic site