scholarly journals Рудно-метасоматическая зональность молибден-порфировой системы Аксу (Северо-Восток Азии)

Author(s):  
O. T. Sotskaya ◽  
◽  
T. I. Mikhalitsyna ◽  
N. E. Savva ◽  
N. A. Goryachev ◽  
...  

The article presents the data from a comprehensive study of the Aksu Mo-porphyry system metasomatites (Korkodon-Nayakhan magmatic activation zone). The halo of metasomatic changes around the porphyry system, associated with the tectonic-block structure of the territory, is shown to be asymmetric. The core of the system is brought to the surface and located in a halo of kalifeldspar- muscovite metasomatites; the northwestern block is elevated and characterized by high-temperature epidote-biotite and epidote-pyroxene propylites, while in the southeastern block there is a consistent transition from kalifeldspar-sericite metasomatites to fragments of argillisite ones. The established zoning is confirmed by geochemical associations and mineralization types from the northwest to the southeast: in the northwest, Au-Bi (As, Cu) at the Solnechnoye ore occurrence; in the center, Mo (Cu, Au) at the Aksu deposit; in the southeast, Ag-Pb-Zn (Cu, Bi, As, Au) at the Vysokoye ore occurrence.

2021 ◽  
Vol 2048 (1) ◽  
pp. 012016
Author(s):  
Ridwan ◽  
A Insani ◽  
Mujamilah ◽  
A Patriati ◽  
G T Sulungbudi ◽  
...  

Abstract One of the keys to success in the process of fuel synthesis for pebble type high temperature nuclear reactors is mastery in kernel synthesis technology which is the core of the fuel itself. In this paper, the results of a comprehensive study of the preparation of a kernel microsphere from ceria stabilized zirconia (CSZ) using the external gelatin method in BATAN will be discussed. Important parameters obtained from this experiment will be the basis for the actual manufacturing of nuclear fuel kernels. Analysis based on measurement data using the Small Angle Neutron Spectrometer (SANS) provides a deep understanding of the mechanism of CSZ microsphere formation, so that at the end it can provide an understanding of how to avoid possible cracks during heat treatment.


Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


2021 ◽  
Vol 1028 ◽  
pp. 193-198
Author(s):  
Budi Adiperdana ◽  
Nadya Larasati Kartika ◽  
Risdiana

Ising core-shell model was proposed to reconstruct superparamagnetism hysteresis in nano-goethite (α-FeOOH). Core and shell set as antiferromagnetic and paramagnetic state respectively. Core and shell radius varies until the theoretical hysteresis fit with experiment hysteresis. At low temperature, the hysteresis reconstructed nicely with 55% antiferromagnetic core contribution and 45% paramagnetic shell contribution. At high temperature, the core-shell model show unrealistic result compared to the pure paramagnetic state.


2008 ◽  
Vol 7 (1) ◽  
pp. 32-43 ◽  
Author(s):  
Kazutaka OHASHI ◽  
Tetsuo NISHIHARA ◽  
Kazuhiko KUNITOMI ◽  
Masaaki NAKANO ◽  
Yujiro TAZAWA ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4212
Author(s):  
Mohamed Said ◽  
Bashirul Haq ◽  
Dhafer Al Shehri ◽  
Mohammad Mizanur Rahman ◽  
Nasiru Salahu Muhammed ◽  
...  

Tertiary oil recovery, commonly known as enhanced oil recovery (EOR), is performed when secondary recovery is no longer economically viable. Polymer flooding is one of the EOR methods that improves the viscosity of injected water and boosts oil recovery. Xanthan gum is a relatively cheap biopolymer and is suitable for oil recovery at limited temperatures and salinities. This work aims to modify xanthan gum to improve its viscosity for high-temperature and high-salinity reservoirs. The xanthan gum was reacted with acrylic acid in the presence of a catalyst in order to form xanthan acrylate. The chemical structure of the xanthan acrylate was verified by FT-IR and NMR analysis. The discovery hybrid rheometer (DHR) confirmed that the viscosity of the modified xanthan gum was improved at elevated temperatures, which was reflected in the core flood experiment. Two core flooding experiments were conducted using six-inch sandstone core plugs and Arabian light crude oil. The first formulation—the xanthan gum with 3% NaCl solution—recovered 14% of the residual oil from the core. In contrast, the modified xanthan gum with 3% NaCl solution recovered about 19% of the residual oil, which was 5% higher than the original xanthan gum. The xanthan gum acrylate is therefore more effective at boosting tertiary oil recovery in the sandstone core.


Author(s):  
S. W. Richards ◽  
W. J. Collins

ABSTRACTCombined field and geophysical data show that plutons from the Bega Batholith are elongate, meridional, wedge-shaped bodies which intruded during a period of regional east–west extension in the Palaeozoic eastern Lachlan orogen, eastern Australia. Plutons within the core of the batholith have intruded coeval, syn-rift sediments and co-magmatic volcanics. The batholith is bound by high-temperature, dip-slip faults, and contains several major NE-trending transtensional faults which were active during batholith construction. In the central part of the batholith, the Kameruka pluton is an asymmetric, eastward-thickening, wedge-shaped body with the base exposed as the western contact, which is characterised by abundant, shallow-dipping schlieren migmatites which contain recumbent folds and extensional shear bands. A shallow (<30°), east-dipping, primary magmatic layering in the Kameruka pluton steepens progressively westward, where it becomes conformable to the east-dipping basal migmatites. The systematic steepening of the layering is comparable to sedimentary units formed during floor depression in syn-rift settings. The present authors suggest that the wedge-shaped plutons of the Bega Batholith are the deeper, plutonic expression of a hot, active rift. The batholith was fed and sustained by injection of magma through sub-vertical dykes. Displacement along syn-magmatic, NE-trending faults suggests up to 25 km of arc-perpendicular extension during batholith construction. The inferred tectonic setting for batholith emplacement is a continental back-arc, where modern half-extension rates of 20–40 mm yr−1 are not unusual, and are sufficient to emplace the entire batholith in ∼1 Ma. This structural model provides a mechanism for the emplacement of some wedge-shaped plutons and is one solution to the ‘room problem’ of batholith emplace


Author(s):  
Alexandre Lecoanet ◽  
Michel Gradeck ◽  
Xiaoyang Gaus-Liu ◽  
Thomas Cron ◽  
Beatrix Fluhrer ◽  
...  

Abstract This paper deals with ablation of a solid by a high temperature liquid jet. This phenomenon is a key issue to maintain the vessel integrity during the course of a nuclear reactor severe accident with melting of the core. Depending on the course of such an accident, high temperature corium jets might impinge and ablate the vessel material leading to its potential failure. Since Fukushima Daiichi accident, new mitigation measures are under study. As a designed safety feature of a future European SFR, bearing the purpose of quickly draining of the corium out of the core and protecting the reactor vessel against the attack of molten melt, the in-core corium is relocated via discharge tubes to an in-vessel core-catcher has been planned. The core-catcher design to withstand corium jet impingement demands the knowledge of very complex phenomena such as the dynamics of cavity formation and associated heat transfers. Even studied in the past, no complete data are available concerning the variation of jet parameters and solid structure materials. For a deep understanding of this phenomenon, new tests have been performed using both simulant and prototypical jet and core catcher materials. Part of these tests have been done at University of Lorraine using hot liquid water impinging on transparent ice block allowing for the visualizations of the cavity formation. Other tests have been performed in Karlsruhe Institute of Technology using liquid steel impinging on steel block.


2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000087-000091
Author(s):  
J. Johansson ◽  
J. Borg

Abstract This paper presents an encapsulation concept that enables the construction of small wireless measurement systems that can operate in industrial environments with ambient temperatures of up to 1200°C. To maximize operational time and minimize size, a layer of thermal insulation is combined with water absorbed in a porous material in the core of the device. The simulated operating time before all of the frozen water at 0°C has transformed into steam at 100°C when the ambient temperature of the device was 1200°C is 21 minutes for a sphere with an outer radius of 4 cm. If the outer radius is increased to 10 cm the simulated operating time increases to 125 minutes. Measurements were performed to validate the design. When a sphere with a radius of 4 cm was subjected to an oven temperature of 1200°C the device held the core temperature at or below 101°C for a total of 25 minutes. The time to reach the boiling point of the water was 9 minutes. Thereafter, the temperature was held constant at 100 +/− 1°C for an additional 16 minutes whereafter a rapid rise in temperature took place once all water had evaporated.


2006 ◽  
Vol 97 (12) ◽  
Author(s):  
D. K. Gupta ◽  
R. J. Fonck ◽  
G. R. McKee ◽  
D. J. Schlossberg ◽  
M. W. Shafer

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