scholarly journals Consequences of microphysical segregation of chemical elements in welded steels

2019 ◽  
Vol 75 (2) ◽  
pp. 206-213
Author(s):  
V. A. Bigeev ◽  
A. B. Sychkov ◽  
M. V. Potapova ◽  
G. Ya. Kamalova
Keyword(s):  
Chemical Composition ◽  
Continuous Casting ◽  
Cross Section ◽  
Nonmetallic Inclusions ◽  
Chemical Elements ◽  
Segregation Coefficient ◽  
Alloying Element ◽  
Magnetic Stirring ◽  
Billet Cross Section ◽  
Electro Magnetic

Defects of metallurgy-originated steel (sub-cored bubbles, impurities, macro- and micro-segregations of chemical elements, nonmetallic inclusions) to a large extent determines the faultiness of metal rolled products. The processes of chemical elements segregation in steel macro- and micro volumes considerably influence its quality. Reasons of microphysical dendrite segregation originating in steels of welding purpose of Св-09Г2С and Св-08ГНМ type considered. Mechanism of dendrites formation studied as well as the segregation degree of chemical elements along the continuously casted billet cross section. To estimate the segregation degree a criteria was used – the segregation coefficient, determined as relation of chemical elements mass shares in different micro-areas (dendrites, inter-dendrite gaps) of continuously casted billet cross section to those elements content by a ladle analysis of a heat or one another in different micro-areas. A heredity of segregation transfer from CC billet to finished wire rod of Св-08Г2С and Св-08ГНМ steels studied. It was determined, that decrease of the number of bainite-martensite areas as a result of decrease of dendrite segregation of chemical elements takes place by minimization within grade chemical composition of both main alloying element and impurities ones. Besides an additional alloying of steel by boron takes place based on boron to nitrogen relation at the level of B/N = 0,8±0,15. It was shown that to decrease the inter-dendrite segregation it is necessary to elaborate and implement effective steel modifying by calcium and REMs regimes as well as electro-magnetic stirring during continuous casting.

Physico-Mechanical and Chemical Characteristics of Amber

2018 ◽  
Vol 277 ◽  
pp. 80-89 ◽  
Author(s):  
Zynovii Malanchuk ◽  
Viktor Moshynskyi ◽  
Yevhenii Malanchuk ◽  
Valerii Korniienko
Keyword(s):  
Chemical Composition ◽  
Cross Section ◽  
Sandy Soil ◽  
Chemical Elements ◽  
Chemical Characteristics ◽  
Geological Cross Section ◽  
Sandy Shale ◽  
The Cost ◽  
Physical And Chemical

Amber of amber-bearing deposits in Rivne-Volyn region of Ukraine has been analyzed. Relying upon instrumental techniques, physical and chemical as well as spectral analyses, and geological prospecting of the deposits, chemical composition and ultimate composition of amber occurring at the territory of Klesiv deposit (Ukraine, Rivne Region, Sarny District) have been identified. Klesiv amber contains the greatest part of inclusions; it contains 18 chemical elements. Basing upon the performed geological cross-section it has been determined that the amber occur in sandy soil and sandy-shale soil. The depth is insignificant – from 1 m to 10 – 15 m. Moreover, to determine the cost, experimental technique has been developed. The technique involves classification of the amber fragments according to their form, dimensions, and colour. Lithologic-and-facies sections of sites of Klesiv deposit have been obtained.

scholarly journals Chemical Composition of the RS CNn-Type Star 33 Piscium

2011 ◽  
Vol 20 (1) ◽  
Author(s):  
G. Barisevišius ◽  
G. Tautvaišienė ◽  
S. Berdyugina ◽  
Y. Chorniy ◽  
I. Ilyin
Keyword(s):  
Chemical Composition ◽  
Chemical Elements ◽  
Type Star

AbstractAbundances of 22 chemical elements, including the key elements and isotopes such as

scholarly journals Seasonal variations in PM10 inorganic composition in the Andean city

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rasa Zalakeviciute ◽  
Katiuska Alexandrino ◽  
Yves Rybarczyk ◽  
Alexis Debut ◽  
Karla Vizuete ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Inductively Coupled Plasma ◽  
Chemical Elements ◽  
Large Fraction ◽  
Urban Pollution ◽  
Optical Emission ◽  
High Elevation ◽  
Water Soluble ◽  
Wet Season ◽  
Soluble Ions

Abstract Particulate matter (PM) is one of the key pollutants causing health risks worldwide. While the preoccupation for increased concentrations of these particles mainly depends on their sources and thus chemical composition, some regions are yet not well investigated. In this work the composition of chemical elements of atmospheric PM10 (particles with aerodynamic diameters ≤ 10 µm), collected at the urban and suburban sites in high elevation tropical city, were chemically analysed during the dry and wet seasons of 2017–2018. A large fraction (~ 68%) of PM10 composition in Quito, Ecuador is accounted for by water-soluble ions and 16 elements analysed using UV/VIS spectrophotometer and Inductively Coupled Plasma—Optical Emission Spectroscopy (ICP-OES). Hierarchical clustering analysis was performed to study a correlation between the chemical composition of urban pollution and meteorological parameters. The suburban area displays an increase in PM10 concentrations and natural elemental markers during the dry (increased wind intensity, resuspension of soil dust) season. Meanwhile, densely urbanized area shows increased total PM10 concentrations and anthropogenic elemental markers during the wet season, which may point to the worsened combustion and traffic conditions. This might indicate the prevalence of cardiovascular and respiratory problems in motorized areas of the cities in the developing world.

Flow Visualization by Means of Contactless Inductive Flow Tomography in the Presence of a Magnetic Brake

2015 ◽  
Vol 15 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Matthias Ratajczak ◽  
Thomas Wondrak ◽  
Klaus Timmel ◽  
Frank Stefani ◽  
Sven Eckert
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Fields ◽  
Flow Field ◽  
Continuous Casting ◽  
Flow Structure ◽  
Cross Section ◽  
Two Dimensional ◽  
Slab Casting ◽  
Two Dimensional Flow

AbstractIn continuous casting DC magnetic fields perpendicular to the wide faces of the mold are used to control the flow in the mold. Especially in this case, even a rough knowledge of the flow structure in the mold would be highly desirable. The contactless inductive flow tomography (CIFT) allows to reconstruct the dominating two-dimensional flow structure in a slab casting mold by applying one external magnetic field and by measuring the flow-induced magnetic fields outside the mold. For a physical model of a mold with a cross section of 140 mm×35 mm we present preliminary measurements of the flow field in the mold in the presence of a magnetic brake. In addition, we show first reconstructions of the flow field in a mold with the cross section of 400 mm×100 mm demonstrating the upward scalability of CIFT.

scholarly journals Soil and Leaf Nutrients Drivers on the Chemical Composition of the Essential Oil of Siparuna muricata (Ruiz & Pav.) A. DC. from Ecuador

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2949
Author(s):  
Juan I. Burneo ◽  
Ángel Benítez ◽  
James Calva ◽  
Pablo Velastegui ◽  
Vladimir Morocho
Keyword(s):  
Gas Chromatography ◽  
Chemical Composition ◽  
Secondary Metabolites ◽  
Essential Oil ◽  
Chemical Elements ◽  
Climatic Conditions ◽  
Gas Chromatography Mass Spectrometry ◽  
Chemical Compositions ◽  
Leaf Nutrients ◽  
First Time

Chemical compositions of plants are affected by the initial nutrient contents in the soil and climatic conditions; thus, we analyzed for the first time the effects of soil and leaf nutrients on the compositions of the essential oils (EOs) of Siparuna muricata in four different localities in Ecuador. EOs were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry (GC/MS) and a gas chromatography/flame ionization detector (GC/FID). Enantiomeric distribution by GC/MS was determined, modifying the enantiomeric separation of β-pinene, limonene, δ-elemene, β-bourbonene, cis-cadina-1 (6), 4-diene and atractylone. A total of 44 compounds were identified. The most representative for L1 were guaiol, atractylone and 4-diene; for L2, cis-cadina-1(6),4-diene and myrcene; for L3, atractylone, myrcene and germacrene B; and finally, L4 germacrene B, myrcene and cis-cadina-1(6),4-diene. Correlations between soil- leaf chemical elements such as Al, Ca, Fe, Mg, Mn, N and Si in the different localities were significant with chemical composition of the essential oil of Siparuna muricata; however, correlations between soil and leaf K, P, and Na were not significant. Cluster and NMDS analysis showed high dissimilarity values of secondary metabolites between four localities related with changes in soil- leaf nutrients. Thus, the SIMPER routine revealed that not all secondary metabolites contribute equally to establishing the differences in the four localities, and the largest contributions are due to differences in guaiol, cis-cadina-1(6),4-diene, atractylone and germacrene. Our investigation showed for the first time the influences of altitude and soil- leaf chemical elements in the chemical composition of the EOs of S. muricata.

Effect of 3D printer enabled surface morphology and composition on coral growth in artificial reefs

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ilse Valenzuela Matus ◽  
Jorge Lino Alves ◽  
Joaquim Góis ◽  
Augusto Barata da Rocha ◽  
Rui Neto ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Chemical Composition ◽  
Chemical Elements ◽  
Three Dimensional ◽  
Coral Growth ◽  
Coralline Algae ◽  
Textured Surface ◽  
Crustose Coralline Algae ◽  
Statistical Parameters ◽  
Content Type

Purpose The purpose of this paper is to prove and qualify the influence of textured surface substrates morphology and chemical composition on the growth and propagation of transplanted corals. Use additive manufacturing and silicone moulds for converting three-dimensional samples into limestone mortar with white Portland cement substrates for coral growth. Design/methodology/approach Tiles samples were designed and printed with different geometries and textures inspired by nature marine environment. Commercial coral frag tiles were analysed through scanning electron microscopy (SEM) to identify the main chemical elements. Raw materials and coral species were selected. New base substrates were manufactured and deployed into a closed-circuit aquarium to monitor the coral weekly evolution process and analyse the results obtained. Findings Experimental results provided positive statistical parameters for future implementation tests, concluding that the intensity of textured surface, interfered favourably in the coralline algae biofilm growth. The chemical composition and design of the substrates were determinant factors for successful coral propagation. Recesses and cavities mimic the natural rocks aspect and promoted the presence and interaction of other species that favour the richness of the ecosystem. Originality/value Additive manufacturing provided an innovative method of production for ecology restoration areas, allowing rapid prototyping of substrates with high complexity morphologies, a critical and fundamental attribute to guarantee coral growth and Crustose Coralline Algae. The result of this study showed the feasibility of this approach using three-dimensional printing technologies.

Transfer of Abrasive Material at Grinding a Titanium Alloy with a Wheel of Cubic Boron Nitride

2021 ◽  
Vol 316 ◽  
pp. 521-526
Author(s):  
Vladimir A. Nosenko ◽  
Alexander V. Fetisov ◽  
Semen P. Kuznetsov
Keyword(s):  
Titanium Alloy ◽  
Chemical Composition ◽  
Boron Nitride ◽  
Chemical Elements ◽  
Cubic Boron Nitride ◽  
Water Soluble ◽  
Alloy Surface ◽  
Ceramic Bond ◽  
Abrasive Tools ◽  
Wear Products

The article summarizes the results of the of the titanium alloy surface morphology and chemical composition study after grinding with a wheel of cubic boron nitride on a ceramic bond. The titanium alloy was treated using the method of cut-in grinding in the finishing mode using a synthetic water-soluble lubricant-cooling liquid that does not contain mineral oil. The research was carried out using the FEI Versa 3D LoVac electron microscope. Digital photos of the titanium alloy surface at different magnifications are given. Individual objects’ morphology allows us to identify them as wear products of abrasive tools. The chemical composition of the selected objects was studied by local x-ray spectral analysis. CBN crystals are partially or completely pressed into the treated surface and covered with a layer of the treated material. On the surface of CBN crystals, there are chemical elements that are part of the abrasive tool bond.

About the possibility of identification of articles from steels, aluminum, copper and alloys on their basis on the expanded micro-impurity elemental composition

2021 ◽  
pp. 51-56
Author(s):  
Yu. B. Sazonov ◽  
D. Yu. Ozherelkov ◽  
R. Sh. Latypov ◽  
E. E. Gorshkov
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Elemental Composition ◽  
Chemical Elements ◽  
Copper Alloys ◽  
Minimal Amount ◽  
Elementary Composition ◽  
Geometric Size ◽  
The Common

Possibility of determination of the fragments and articles made of different grades of steel aluminium and copper alloys and their affiliation to the common melt was examined via the methods of photoelectric spectral analysis based on composition of micro-impurities. Chemical elements with micro-impurities were revealed; they allow to determine affiliation of metal fragments to one melt. Ultimately possible deviations of micro-impurities within one melt were obtained. The technique allowing to establish affiliation of fragments to the common melt based on their elementary composition of micro-impurities with minimal amount of measurements was suggested based on the obtained results. The minimal geometric size of a sample available for analysis was determined; it allows to classify the examined fragments to one melt based on the results of investigation of expanded elementary composition of micro-impurities. Practical opportunities of this technique were displayed on the example of the alloys with different chemical composition.

scholarly journals Kaolinite Claystone-Based Geopolymer Materials: Effect of Chemical Composition and Curing Conditions

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 444 ◽  
Author(s):  
Pavlína Hájková
Keyword(s):  
Chemical Composition ◽  
Water Glass ◽  
Chemical Elements ◽  
Solidification Process ◽  
Ease Of Use ◽  
Raw Material ◽  
Curing Conditions ◽  
Low Viscosity ◽  
Lower Porosity ◽  
Curing Methods

This work describes the role of chemical composition and curing conditions in geopolymer strength, leachability of chemical elements and porosity. The study focuses on geopolymer material prepared from calcined kaolinite claystone, which is not studied frequently as a raw material for geopolymer production, although it has a high application potential as it is easily commercially available and allows preparation of geopolymers with low viscosity. The composition of geopolymers and their curing methods were selected considering their ease of use in the praxis. Therefore, the potassium water glass itself was used as alkali activator without any KOH or NaOH addition. Chemical composition was changed only by the density of water glass in the range of 1.2 to 1.6 g·cm−3. Geopolymers were cured at a temperature within the range of 5 °C–70 °C to speed up the solidification process as well as by microwave radiation. High compressive strengths were obtained for geopolymers with the highest densities of the water glass (1.5 and 1.6 g·cm−3) in dependence on various curing conditions. Higher strengths were achieved in the case of samples where the solidification was not accelerated. The samples cured at lower temperatures (5 °C) showed lower porosity compared to the other curing types. The lowest leachability of Si and alkalis was reached for the samples with water glass density 1.5 g·cm−3.

scholarly journals Analysis of Chemical Composition Homogeneity in the Cross-section of the Rods Produced from Alloys of 6xxx Group

2020 ◽  
Vol 66 (3) ◽  
pp. 139-148
Author(s):  
Maja Vončina ◽  
Peter Cvahte ◽  
Ana Kračun ◽  
Tilen Balaško ◽  
Jožef Medved
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Cross Section ◽  
Cross Sections ◽  
Intermetallic Phases ◽  
Scanning Calorimetry ◽  
Good Corrosion Resistance ◽  
Energy Dispersion Spectrometer ◽  
High Casting Speed ◽  
The Cross

AbstractThe alloys from Al–Mg–Si system provide an excellent combination of mechanical properties, heat treatment at extrusion temperature, good weldability, good corrosion resistance and formability. Owing to the high casting speed of rods or slabs, the solidification is rather non-equilibrium, resulting in defects in the material, such as crystalline segregations, the formation of low-melting eutectics, the unfavourable shape of intermetallic phases and the non-homogeneously distributed alloying elements in the cross-section of the rods or slabs and in the entire microstructure. The inhomogeneity of the chemical composition and the solid solution negatively affects the strength, the formability in the warm and the corrosion resistance, and can lead to the formation of undesired phases due to segregation in the material. In this experimental investigation, the cross-sections of the rods from two different alloys of the 6xxx group were investigated. From the cross-sections of the rods, samples for differential scanning calorimetry (DSC) at three different positions (edge, D/4 and middle) were taken to determine the influence of inhomogeneity on the course of DSC curve. Metallographic sample preparation was used for microstructure analysis, whereas the actual chemical composition was analysed using a scanning electron microscope (SEM) and an energy dispersion spectrometer (EDS).

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