scholarly journals INVESTIGATION OF INFLUENCE OF PLASMOCHEMICAL MODIFICATION ON MACRO- AND MICROSTRUCTURE OF SURFACE LAYER OF AUTOCLAVE WALL MATERIALS

2020 ◽  
pp. 4-10
Author(s):  
N. Bondarenko ◽  
D. Bondarenko ◽  
N. Burlakov ◽  
Lyudmila Bragina
Keyword(s):  
Surface Layer ◽  
Multilayer Structure ◽  
Liquid Glass ◽  
Plasma Torch ◽  
High Plasma ◽  
Decorative Coating ◽  
Deep Layers ◽  
Wall Materials ◽  
Maximum Surface Temperature ◽  
High Temperature Effect

studies of the high-temperature effect of a plasma torch on the formation of a multilayer structure of the protective and decorative coating of autoclave wall materials are presented. The tasks of the work included studies: a temperature gradient in a multilayer protective-decorative coating; chemical composition of the fused, intermediate and deep layers of the protective and decorative coating; influence of sodium liquid glass on the formation of macro- and microstructures of protective and decorative coatings under the influence of plasma; processes of thermal diffusion and redistribution of oxides in the fused, intermediate and deep layers. It was found that when the plasma torch was treated with autoclave wall materials, the surface layer was heated to a depth of 3000 μm, and the maximum surface temperature reached 2000 °C. The pattern of the change in the structure of the fused and intermediate layer is revealed. It is shown that the preliminary impregnation of the surface of silica brick during plasma treatment due to the formation of a low-melting melt eliminates microcracks in its deep layers, and high plasma temperatures promote intensive evaporation of sodium and calcium oxides from the fused layer.

scholarly journals Ferrosilicate glass ceramics based on wastes from ore concentration

2021 ◽  
pp. 95-103
Keyword(s):  
Surface Layer ◽  
Iron Ore ◽  
Glass Ceramics ◽  
Redox Conditions ◽  
Glass Technology ◽  
Crystalline Phases ◽  
Reducing Conditions ◽  
Deep Layers ◽  
Hematite Fe2o3 ◽  
Crystallization Of Glass

We showed in this work that there is a possibility of recycling the wastes derived from iron ore concentration by using glass technology. The compositions of new glass ceramics with high technological and decorative properties were developed. The influence of Al2O3, MgO and Na2O additives to the waste from ore benefication on the parameters of the synthesized glass and its crystallization products was studied. The optimal temperatures of synthesis, annealing and crystallization of glass samples in the systems (Fe2O3–FeO)–SiO2–Al2O3–Na2O and (Fe2O3–FeO)–SiO2–Al2O3–MgO were shown to be 1450100С, 500–6000С and 700–8000C, respectively. It was established that the redox conditions of crystallization of glasses in the system (FeO–Fe2O3)–SiO2–Al2O3–Na2O strongly affect the nature of the iron-containing phases that are formed: oxidative conditions favors the formation of hematite (Fe2O3) and aegirinite (Na2OFe2O34SiO2), whereas reducing conditions contributes to the formation of wustite (FeO) and fayalite (2FeOSiO2). In the system (FeO–Fe2O3)–SiO2–Al2O3–MgO under both oxidative and reducing conditions of crystallization, the same crystalline phases appear: olivine (2(Mg,Fe)OSiO2), hercin (FeOAl2O3) and iron metasilicate (FeOSiO2). It was shown that the crystallization of samples under reducing conditions allows producing materials with higher microhardness. The surface layer of glasses and glass ceramics exhibited less microhardness than their deep layers.

Chipboards with Plasma Protective Decorative Coatings

2019 ◽  
Vol 974 ◽  
pp. 90-95 ◽  
Author(s):  
Nadezhda I. Bondarenko ◽  
Sergey A. Chuev ◽  
Ludmila A. Dogaeva ◽  
Tatiana A. Jalovencko
Keyword(s):  
Chemical Modification ◽  
Sheet Glass ◽  
Intermediate Layer ◽  
Liquid Glass ◽  
Front Surface ◽  
Electric Arc ◽  
Alkali Resistance ◽  
Arc Plasma ◽  
Plasma Chemical ◽  
Decorative Coating

A plasma technology has been developed for the production of chipboard with vitreous protective decorative coatings. To prevent high temperatures of the plasma jet from being applied to the front surface of the chipboard, an intermediate layer was applied, which included a mixture of sodium liquid glass with colored glass powders based on profiled and sheet cullet. The technology of a two-stage deposition of an intermediate layer before plasma spraying of the main vitreous coating has been developed. The technology provides for the preliminary front surface preparation and the liquid glass application on a wood chipboard, the intermediate layer application and subsequent drying at 95 °C. The adhesion strength of the intermediate layer with the matrix was 1.6–1.8 MPa. The optimal technological parameters of plasma-chemical modification of a protective decorative coating based on fine powders of sheet and profiled glasses have been established: the power of an electric arc plasma installation operation is 8 kW, the flow rate of argon plasma gas - 2.0 m3 /hour. It is shown that the water resistance of protective decorative coatings based on profiled and sheet glass is III hydrolytic class. Vitreous coatings had high reliability and durability, in particular, acid resistance, alkali resistance and microhardness. Due to the electric arc plasma installations use for plasma-chemical modification of protective decorative coatings based on profiled and sheet glass cullet, the technology is resource and energy efficient, and is also recommended for introduction both in furniture industry and in the construction industry.

Copper-Based Ohmic Contacts For The SiGe/Si Heterojunction Bipolar Transistor (HBT) Structure

1999 ◽  
Vol 564 ◽  
Author(s):  
K. Das ◽  
S. A. Alterovitz
Keyword(s):  
Surface Layer ◽  
Sheet Resistance ◽  
Multilayer Structure ◽  
Ohmic Contacts ◽  
Bipolar Transistor ◽  
Heterojunction Bipolar Transistor ◽  
Low Resistance ◽  
Resistance Surface ◽  
Specific Contact ◽  
P Type

AbstractA Cu-based metallization scheme has been studied for establishing low resistance contacts for a Si/SiGe/Si heterojunction bipolar transistor (HBT) structure. As-grown doped layers were further implanted with BF2 and As ions for the p-type base and n-type emitter layers, respectively, in order to produce a low sheet resistance surface layer. Contacts were metallized using an e-beam deposited multilayer structure of Ti/Cu/Ti/Al. Specific contact resistances of the order of 10−7 Ω cm2 or lower were obtained.

scholarly journals Fractal behavior of soil water storage at multiple depths

2016 ◽  
Author(s):  
Wenjun Ji ◽  
Mi Lin ◽  
Asim Biswas ◽  
Bing C. Si ◽  
Henry W. Chau ◽  
...  
Keyword(s):  
Surface Layer ◽  
Soil Water ◽  
Management Practices ◽  
Surface Soil ◽  
Fractal Theory ◽  
Water Storage ◽  
Water Dynamics ◽  
Soil Water Storage ◽  
Scaling Properties ◽  
Deep Layers

Abstract. Spatio-temporal behavior of soil water is essential to understand the science of hydrodynamics. Data intensive measurement of surface soil water using remote sensing has established that the spatial variability of soil water can be described using the principle of self-similarity (scaling properties) or fractal theory. This information can be used in determining land management practices provided the surface scaling properties hold at deep layer. Current study examined the scaling properties of sub-surface soil water and its relationship to surface soil water, thereby serving as the supporting information for the plant root and vadose zone models. Soil water storage (SWS) down to 1.4 m depth at seven equal intervals was measured along a transect of 576 m for 5 years. The surface SWS showed multifractal nature only during the wet period (from snowmelt until mid to late June with large SWS) indicating the need of multiple scaling indices in transferring soil water variability information over multiple scales. However, with increasing depth, the SWS became monofractal in nature indicating the need of single scaling index to upscale/downscale soil water variability information. The dynamic nature made the surface layer soil water in the wet period highly variable compared to the deep layers. In contrast, all soil layers during the dry period (from late June to the end of the growing season with low SWS) were monofractal in nature, probably resulting from the high evapotranspirative demand of the growing vegetation that surpassed other effects. This strong similarity between the scaling properties at the surface layer and deep layers provides the possibility of inferring about the whole profile soil water dynamics using the scaling properties of the easy-to-measure surface SWS data.

scholarly journals PLASMOCHEMICAL MODIFICATION OF WALL BUILDING MATERIALS

2020 ◽  
pp. 11-18
Author(s):  
Vasiliy Bessmertnyy ◽  
O. Puchka ◽  
Diana Bondarenko ◽  
I. Antropova ◽  
Lyudmila Bragina
Keyword(s):  
Aluminum Oxide ◽  
Phase Transformations ◽  
Liquid Glass ◽  
Building Materials ◽  
Sodium Oxide ◽  
Liquid Sodium ◽  
High Alumina ◽  
Oxide Content ◽  
Layer By Layer ◽  
Decorative Coating

the aim of the work is to study the effect of a high-temperature plasma torch on the processes of phase transformations and layer-by-layer modification of the protective and decorative coating on concrete using as a filler a mixture of quartz sand and hollow glass microspheres. The main tasks included: investigation of the processes of evaporation and thermal diffusion of oxides of plasma-coated coatings; study of phase transformations in the melt and its subsequent crystallization in the process of rapid spontaneous cooling of the fused protective and decorative coating; study of the effect of sodium liquid glass on the processes of polymorphic transformations of alumina and the formation of micro-wicks due to the intense diffusion of sodium oxide; study of operational characteristics of protective and decorative coatings. It was established that the initial phases in the protective-decorative coating are α-Al2O3 and CaO∙6Al2O3 (β-Al2O3), and the liquid sodium glass in the coating leads additionally to the formation of Na2O∙11Al2O3. The top layer of the protective and decorative coating is Na–Ca–Al–Si glass with regions of heterogeneities containing an increased content of sodium oxide. The content of aluminum oxide in the protective and decorative coating based on the battle of high-alumina refractory was 95.1 %. The introduction into the coating composition of sodium liquid glass minimizes the processes of dehydration of the binding component and changes the chemical composition of the protective and decorative coating. Reduction of the aluminum oxide content to 83.0 % affects the microhardness indicators. Microhardness of the concrete surface due to the introduction of liquid glass is reduced from 2510 HV to 887 HV.

scholarly journals Research on marine environment and coral distribution on Nam Yet island using VNRedsat-1 and QuickBird images

2019 ◽  
Vol 19 (3B) ◽  
pp. 189-202
Author(s):  
Do Huy Cuong ◽  
Le Dinh Nam ◽  
Nguyen Xuan Tung ◽  
Nguyen The Luan ◽  
Bui Thi Bao Anh ◽  
...  
Keyword(s):  
Surface Layer ◽  
Coral Reef ◽  
Surface Temperature ◽  
Sea Surface ◽  
Adjacent Area ◽  
Environmental Characteristics ◽  
Research Results ◽  
Deep Layers ◽  
Sand Accumulation ◽  
Marine Environmental

Based on the processing of VNRedsat-1 and QuickBird images in the area of Truong Sa archipelago, the research results showed the efficiency of assessing marine environmental characteristics in surroundings of these islands. In this paper, we presented the research results on Nam Yet island and adjacent area. The marine parameters in this research include sea surface temperature (SST) and chlorophyll-a concentration in the surface layer as well as in the deep layers of 20m and 40m, the distributions of the ground objects such as coral shelf, sand accumulation, coral reef combined with seagrass and seaweed. The accuracy of assessment of supervised and unsupervised classified results is approximate of 87.8%. The research results allowed assessing the environmental characteristics, warning of the risk of erosion and coastal line change in the study area.

The oxidation of Inconel alloy MA754 at low oxidation potential

1983 ◽  
Vol 41 ◽  
pp. 218-219
Author(s):  
D. N. Braski ◽  
P. D. Goodell ◽  
J. V. Cathcart ◽  
R. H. Kane
Keyword(s):  
Surface Layer ◽  
Oxidation Potential ◽  
Metal Interface ◽  
Elevated Temperature Strength ◽  
Surface Conditions ◽  
Inconel Alloy ◽  
Inco Alloy ◽  
Resistance To Oxidation ◽  
Oxide Particles ◽  
Cold Worked

It has been known for some time that the addition of small oxide particles to an 80 Ni—20 Cr alloy not only increases its elevated-temperature strength, but also markedly improves its resistance to oxidation. The mechanism by which the oxide dispersoid enhances the oxidation resistance is being studied collaboratively by ORNL and INCO Alloy Products Company.Initial experiments were performed using INCONEL alloy MA754, which is nominally: 78 Ni, 20 Cr, 0.05 C, 0.3 Al, 0.5 Ti, 1.0 Fe, and 0.6 Y2O3 (wt %).Small disks (3 mm diam × 0.38 mm thick) were cut from MA754 plate stock and prepared with two different surface conditions. The first was prepared by mechanically polishing one side of a disk through 0.5 μm diamond on a syntron polisher while the second used an additional sulfuric acid-methanol electropolishing treatment to remove the cold-worked surface layer. Disks having both surface treatments were oxidized in a radiantly heated furnace for 30 s at 1000°C. Three different environments were investigated: hydrogen with nominal dew points of 0°C, —25°C, and —55°C. The oxide particles and films were examined in TEM by using extraction replicas (carbon) and by backpolishing to the oxide/metal interface. The particles were analyzed by EDS and SAD.

Structural analysis of the surface-layer protein of spirillum serpens by high-resolution electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 738-739
Author(s):  
W. H. Wu ◽  
R. M. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Structural Analysis ◽  
High Resolution ◽  
Low Dose ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Surface Layer Protein ◽  
Morphological Unit ◽  
Resolution Electron

Spirillum serpens possesses a surface layer protein which exhibits a regular hexagonal packing of the morphological subunits. A morphological model of the structure of the protein has been proposed at a resolution of about 25 Å, in which the morphological unit might be described as having the appearance of a flared-out, hollow cylinder with six ÅspokesÅ at the flared end. In order to understand the detailed association of the macromolecules, it is necessary to do a high resolution structural analysis. Large, single layered arrays of the surface layer protein have been obtained for this purpose by means of extensive heating in high CaCl2, a procedure derived from that of Buckmire and Murray. Low dose, low temperature electron microscopy has been applied to the large arrays.As a first step, the samples were negatively stained with neutralized phosphotungstic acid, and the specimens were imaged at 40,000 magnification by use of a high resolution cold stage on a JE0L 100B. Low dose images were recorded with exposures of 7-9 electrons/Å2. The micrographs obtained (Fig. 1) were examined by use of optical diffraction (Fig. 2) to tell what areas were especially well ordered.

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