scholarly journals Physical Nature of the Processes in Structure Forming, Phase and Chemical Composition of pipe Permanent Joints when MMA Welding

2016 ◽  
Vol 125 ◽  
pp. 012010 ◽  
Author(s):  
D P Il’yaschenko ◽  
D A Chinakhov ◽  
V I Danilov ◽  
I D Sadykov
Keyword(s):  
Chemical Composition ◽  
Physical Nature ◽  
Mma Welding ◽  
Phase And Chemical Composition

Effect of Chemical Composition of Glassy Phase of Porcelain Stoneware on Product Brittleness

2020 ◽  
Vol 989 ◽  
pp. 254-259
Author(s):  
Irina A. Pavlova ◽  
A.S. Kiyko ◽  
Elena Farafontova
Keyword(s):  
Chemical Composition ◽  
Brittle Failure ◽  
Glassy Phase ◽  
High Price ◽  
Firing Process ◽  
Small Object ◽  
Quenching Temperature ◽  
Floor Tiles ◽  
Increased Strength ◽  
Phase And Chemical Composition

During the operation of porcelain stoneware sometimes there is a type of defects associated with crumbling from the edge of tile. In addition, cracks occur when a small object is fallen and during transportation of the products. Compared to conventional ceramic floor tiles, porcelain stoneware has increased strength, which explains its high price. The brittle failure is most likely, due to the hardening of glassy phase of tiles during cooling stage of the firing process. As a rule, the quenching temperature depends on the chemical composition of the glassy phase formed during firing. Both the phase and chemical composition of porcelain stoneware, and the chemical composition of the glassy phase are determined.

scholarly journals Physical Properties of the Interplanetary Dust

1971 ◽  
Vol 12 ◽  
pp. 377-388
Author(s):  
Martha S. Hanner
Keyword(s):  
Optical Properties ◽  
Spatial Distribution ◽  
Chemical Composition ◽  
Physical Properties ◽  
Physical Nature ◽  
Interplanetary Dust ◽  
Physical Structure ◽  
Dust Particles ◽  
Cometary Material ◽  
Direct Condensation

The interplanetary dust may be composed of cometary material, interstellar grains, debris from asteroidal collisions, primordial material formed by direct condensation, or contributions from all of these sources. Before we can determine the origin of the dust, we need to know its physical nature, spatial distribution, and the dynamical forces that act on the particles. The spatial distribution and dynamics are separately treated in this symposium by Roosen. We discuss here the physical characteristics of the dust particles: their size distribution, chemical composition, physical structure, and optical properties.

Gastric emptying of ordinary food: effect of antrum on particle size

1980 ◽  
Vol 239 (3) ◽  
pp. G133-G135 ◽  
Author(s):  
J. H. Meyer
Keyword(s):  
Particle Size ◽  
Small Intestine ◽  
Gastric Emptying ◽  
Chemical Composition ◽  
Quantitative Methods ◽  
Food Effect ◽  
Physical Nature ◽  
Gamma Cameras ◽  
Early Results ◽  
Rapid Labeling

The lack of reliably quantitative methods has delayed understanding how the stomach empties and processes foods. Rapid refinement of gamma cameras has prompted the development of several methods for labeling of ordinary foods with radionuclides. These methods allow rapid labeling with tightly adherent nuclides and are safe for studies both in animals and humans. Nuclide-labeled foods have also permitted detailed analyses of gastric emptying in animals prepared with chronic duodenal fistulas. Early results indicate that the stomach retains foods until these are fragmented into particles smaller than 0.5 mm in diameter, and that this sieving is achieved in the antral region of the stomach. The speed of fragmentation of foods into particles of this size as well as the speed of emptying appear to be closely regulated by chemoceptive mechanisms in the small intestine, which can inhibit these processes. Thus, chemical composition of the meal regulates gastric emptying as well as the physical nature of the food, which determines how easily it can be fragmented by the stomach.

High Temperature Sulphidation Behavior of Fe20Cr6Al-Y,Hf Steel

2008 ◽  
Vol 595-598 ◽  
pp. 763-768
Author(s):  
Martah Homa ◽  
Zbigniew Żurek
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Vapor Pressure ◽  
Phase Analysis ◽  
High Temperature Corrosion ◽  
Vapor Pressures ◽  
Scale Layer ◽  
Phase And Chemical Composition ◽  
Xrd Techniques ◽  
Scale Surface

The high temperature corrosion behavior of Fe20Cr6Al-Y,Hf steel was studied in the range of temperature 800-1000oC in H2/H2S atmospheres at pS2=10-2 ,10-3 and 10-4 Pa sulphur vapor pressures. Kinetics depend on the temperature and sulphur vapor pressure. After 24 hours the whole specimen was practically consumed because the samples were 0,06 cm thick. Morphology of the scales have been performed by SEM techniques. Phase and chemical composition have been studied by EDX and XRD techniques. It was found that scale formed on Fe20Cr6Al-Y,Hf alloy was built with porosity sulphides layer. EDX analysis of the scale surface show that the any aluminum, hafnium and yttrium sulfides were found in the formed scale layer, however small amounts of Al2S3 was detected in scale/steel interface. Also internal sulphidation was observed. A phase analysis of the formed scale revealed that it is composed mainly of an FeS, Fe7S8 phases and CrS, Cr5S6. Result were compared with data obtained on the pure Fe and Cr samples.

scholarly journals Study of Phase and Chemical Composition of Bi1-xNdxFeO3 Powders Derived by Pressureless Sintering

2013 ◽  
Vol 58 (4) ◽  
pp. 1371-1376 ◽  
Author(s):  
J. Dzik ◽  
A. Lisinska-Czekaj ◽  
A. Zarycka ◽  
D. Czekaj
Keyword(s):  
Weight Loss ◽  
Chemical Composition ◽  
Structural Phase ◽  
Simultaneous Thermal Analysis ◽  
Orthorhombic Symmetry ◽  
Pressureless Sintering ◽  
Oxide Powders ◽  
Neodymium Concentration ◽  
Temperature Ranges ◽  
Phase And Chemical Composition

Abstract In the present paper studies on Bi1-xNdxFeO3 for x =0.1-0.4 are reported. The mixed oxide method followed with pressureless sintering was employed for ceramics fabrication. Thermal behavior of stoichiometric mixtures of simple oxide powders, viz. Bi2O3, Nd2O3 and Fe2O3 was studied by simultaneous thermal analysis. It was found that with an increase in neodymium content the weight loss increased from 0.75% to 3.16% for x =0.1 and x =0.4, respectively. It was found that weight loss took place mainly within two temperature ranges, namely ΔT1 ≈(300-400)0C and ΔT2 ≈(600-800)°C. Bi1-xNdxFeO3 ceramics was studied in terms of its phase composition (X-ray phase analysis) and chemical composition (EDS method) at room temperature. It was found that Bi1-xNdxFeO3 suffered structural phase transition from rhombohedral to orthorhombic symmetry with an increase in neodymium concentration x within the range x =(0.2-0.3).

scholarly journals Structural-textural nature and sorption properties of limestones from the mesozoic-neogene contact zone in the Bełchatów deposit

2015 ◽  
Vol 31 (4) ◽  
pp. 75-94 ◽  
Author(s):  
Elżbieta Hycnar
Keyword(s):  
Chemical Composition ◽  
Contact Zone ◽  
Direct Contact ◽  
Textural Properties ◽  
Sorption Properties ◽  
Mechanical Compaction ◽  
Karst Formation ◽  
Lignite Mine ◽  
Inner Surface ◽  
Phase And Chemical Composition

Abstract Limestones of the Jurassic age are one of the most important minerals accompanying the Bełchatówlignite deposits. They are part of the Bełchatów and Szczerców rock subsoil complex and form natural hillsides of exploitation fields, which are gradually being exposed due to the progressive exploitation of coal. So far in Bełchatów Lignite Mine nearly 2 million tonnes of limestones have been extracted, which were used in the form of highway aggregate. For the extraction (mineral recovery) approx. 2 million tonnes remained in the Bełchatów field and from 20 to nearly 70 million tonnes in the Szczerców field. The limestones occurring in the deposit Bełchatów are differential qualitatively. Those situated in direct contact with Neogene deposits are characterized by strong karstification (karst formation), and even occur in the form of detrital minerals. Furthermore, they are covered by processes of secondary mineralization. These processes caused significant diversity of phase and chemical composition, and thereby have contributed to reducing the CaCO3 content. Despite this, limestones from the Mesozoic-Neogene contact zone possess excellent sorption properties in respect of SO2 in conditions of fluidised furnaces. These properties are determined firstly by their structural-textural nature, and above all with the presence of calcite sparite crystals in microcrystalline groundmass, of micropores, tectonic discontinuities, fracturings and compaction slits. With their presence, both decarbonatization and sorption processes proceed effectively. The CO2 particles are quickly removed from the structures of calcite crystals, and SO2 is able to penetrate into the interior of the sorbent grains where are absorbed on the inner surface of pores arising as a result of the decarbonatization process. These characteristic structural and textural properties of the surveyed limestones have been shaped at the diagenesis and epigenesis stage. This contributed to all chemical and mechanical compaction and cementation processes, as well as the dissolution and recrystallization processes. Despite the low CaCO3 content limestones from the Mesozoic-Neogene contact zone can be successfully used in the form of sorbents to reduce SO2 emissions in conditions of fluidised furnaces.

scholarly journals A Study of the Pore Surface State of Porous TiNi-based Materials Obtained by SHS at Various Ignition Temperatures

2017 ◽  
Vol 2 (1) ◽  
pp. 25
Author(s):  
S.G. Anikeev ◽  
V.N. Khodorenko ◽  
M.R. Mukhamedov ◽  
V.E. Gunther
Keyword(s):  
Surface Layer ◽  
Chemical Composition ◽  
Porous Material ◽  
Variable Thickness ◽  
Secondary Phase ◽  
Structural Features ◽  
Alloy Formation ◽  
Pore Surface ◽  
P 75 ◽  
Phase And Chemical Composition

Structural features of porous TiNi-based materials obtained by SHS at temperatures of synthesis beginning of400 Cand600 Chave been investigated. It is found that finely porous material with a porosity P=75 % was obtained at the temperature of400 C. A surface of pore walls contains a dendritic relief, oxycarbidenitride layer and a multitude of secondary phase particles. Phase and chemical composition of the material is non-uniform. SHS material obtained at the synthesis beginning temperature of600 °Cis characterized as a coarse-porosity one P=65 %. Nano- and micropores are practically absent. The oxycarbidenitride surface layer with a variable thickness is substantially free of secondary inclusions due to the more complete processes of alloy formation. This layer has an own substructure based on carbonitride and oxynitride layers.

scholarly journals Provenance and production technology of late medieval ‘Besztercebánya/Banská Bystrica–type’ high-quality stove tiles

2020 ◽  
Vol 12 (12) ◽  
Author(s):  
Dorottya Györkös ◽  
Bernadett Bajnóczi ◽  
György Szakmány ◽  
Máté Szabó ◽  
Ralf Milke ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Raw Materials ◽  
Ceramic Body ◽  
Analytical Investigation ◽  
X Ray Diffraction ◽  
High Quality ◽  
Late Medieval ◽  
Production Techniques ◽  
Phase And Chemical Composition ◽  
Primary Groups

AbstractA unique collection of high-quality late medieval (fifteenth–sixteenth century) glazed and unglazed stove tiles from the northern part of the Carpathian Basin is of great interest to archaeologists and art historians. It is yet to be determined if these products, which are characterised by similar features, were produced in a single workshop, perhaps in Besztercebánya/Banská Bystrica (in present-day Slovakia), or in several workshops throughout the region. The first systematic multi-analytical investigation was carried out on the ceramic body and glaze of one hundred and seventeen tile fragments from six sites (Besztercebánya/Banská Bystrica, Fülek/Fiľakovo, and Csábrág/Čabraď in Slovakia; Salgó, Eger, and Szécsény in Hungary) using polarising microscopy, X-ray diffraction, electron microprobe, and Raman microspectroscopy analyses to determine the raw materials and production techniques used. Based on the petrographic characteristics, phase and chemical composition of the ceramic body, and the chemical composition and colourants of the glazes, the stove tiles can be classified into three primary groups. Tiles from different sites are different to each other, only the tiles from the Hungarian sites and from Fülek/Fiľakovo are similar. Thus, it is probable that the tiles were produced in several (at least three) workshops in the region from where they were then dispersed. The technological knowledge of the master(s) producing the polychrome Csábrág/Čabraď tiles with tin-opacified glazes was higher than that of the master(s) producing the other tiles. However, the exact location of the workshops as well as their existence through time is still in unknown.

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