Microstructural Development During Suspension Hydration of Tricalcium Silicate Under “Floating” and Fixed pH Conditions

1986 ◽  
Vol 85 ◽  
Author(s):  
A. R. Ramachandran ◽  
Michael W. Grutzeck
Keyword(s):  
Chemical Composition ◽  
Tricalcium Silicate ◽  
Solution Phase ◽  
Microstructural Development ◽  
Ph Conditions ◽  
Hydrate Products

ABSTRACTThe suspension hydration of tricalcium silicate (water-solid 500) has been studied under both floating and fixed pH (8 to 12) conditions. In addition to solution analysis, the microstructure and chemical composition of the hydrate products was also studied. The results are interpreted as suggesting the existence of two C-S-H phases in the system CaO-SiO2-H2O, the stabilization of each being dependent on the pH of the solution phase.

Development of PM Stainless Steels with Improved Properties through Liquid Phase Sintering

2007 ◽  
Vol 534-536 ◽  
pp. 661-664 ◽  
Author(s):  
C. Tojal ◽  
T. Gómez-Acebo ◽  
F. Castro
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Master Alloy ◽  
Stainless Steels ◽  
Austenitic Stainless Steels ◽  
Steel Powder ◽  
Liquid Phase Sintering ◽  
Microstructural Development ◽  
Master Alloys ◽  
Microstructure Density

The use of boron for successfully obtaining high density PM stainless steels with improved mechanical properties and corrosion resistance is presented. Boron is added as part of master alloys which have been specifically designed to provide the formation of wetting liquid phases with excellent characteristics for producing controlled densification and alloying of 316L and 304L austenitic stainless steels. The as-sintered density and properties of these alloys is determined by the amount of master alloy, the chemical composition of the stainless steel powder, the sintering temperature and time. The microstructural development and alloy homogenisation are determined by the chemical composition of the Fe-based powder and the chemical reactions taking place between the basic powder and the master alloy particles during high temperature sintering. The use of this master alloy is shown to lead to stainless steels with outstanding combinations of strength and ductility. The influence of alloying and the sintering conditions on the final microstructure, density, corrosion resistance and tensile properties is also discussed.

Fabrication of superhydrophobic surface with discarded silicone under arc exposure

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103739-103743 ◽  
Author(s):  
Zhengyong Huang ◽  
Jian Li ◽  
Feipeng Wang ◽  
Xinzhu Yan ◽  
Yuan Wei
Keyword(s):  
Chemical Composition ◽  
Superhydrophobic Surface ◽  
Microstructural Development ◽  
Hydrophobic Surfaces ◽  
Corrosive Liquid

Super-hydrophobic surfaces can be fabricated based on discarded silicone after arc exposure. Hydrophobicity, microstructural development, chemical composition, corrosive liquid resistance, and the microscopic process of contaminant elimination of the surface are presented.

scholarly journals Change of the Chemical and Mineralogical Composition of the Slag during Oxygen Blowing in the Oxygen Converter Process

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 844 ◽  
Author(s):  
Dana Baricová ◽  
Alena Pribulová ◽  
Peter Futáš ◽  
Branislav Buľko ◽  
Peter Demeter
Keyword(s):  
Chemical Composition ◽  
Oxygen Converter ◽  
Steel Production ◽  
Mineralogical Composition ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Structural Components ◽  
Assimilation Process ◽  
Chemical And Mineralogical Composition ◽  
Calcium Ferrites

The article presents the results of the investigation of changes in the chemical and mineralogical composition of slag during steel production in a blown oxygen converter. This process was monitored using the slag samples that were collected during the period when oxygen blowing into an oxygen converter was interrupted. The slag samples were collected after 150 s (2.5 min), then after 5, 8, 11, and 24 min of oxygen blowing, and in minute 27 when oxygen blowing was terminated. The sampling was carried out within five consecutive melting processes. The article presents and documents the changes in the contents of CaO, CaO (free), Fe (total), FeO, SiO2, and in the basicity of the slag during oxygen blowing. It also provides the characteristics of individual structural components formed during oxygen blowing and a detailed description of the lime assimilation process, including the formation of the final structure of the slag, consisting of dicalcium silicate (2CaO·SiO2), tricalcium silicate (3CaO·SiO2), RO-phase, and calcium ferrites (2CaO·Fe2O3). The results of the investigation of the changes in the chemical composition of the slag during oxygen blowing in an oxygen converter were compared with the changes in the structural composition of the slag.

Structural Organization of Early Gels and Precipitates of Chemically Bonded Ceramics

1988 ◽  
Vol 121 ◽  
Author(s):  
William B. White ◽  
Dorothy J. Vesper ◽  
Julia Kraus
Keyword(s):  
Chemical Composition ◽  
Raman Spectra ◽  
Structural Organization ◽  
Structural Characteristics ◽  
Low Ph ◽  
Colloidal Gels ◽  
Silica Alumina ◽  
Fine Structures ◽  
Ph Conditions ◽  
Reduced Water

ABSTRACTCeramic precursor materials in the silica-alumina-phosphous pentoxide system can be retained as solutions under suitably high or low pH conditions. Molecular species in these solutions have been characterized by their sharp, well-defined Raman spectra. Changes in pH or reduced water activity by addition of miscible organic solvents takes the system across sharp precipitation boundaries. Precipitates can take the form of colloidal gels, polymerized gels, or crystallites depending on chemical composition and rate of precipitation. Raman spectra of precipitates immersed in their parent solutions have much less structure and broader bands. Information of the structural characteristics of the precipitates are deduced from band widths and the amount of fine structures related to the coherence length for Raman scattering. Phosphate-rich compositions tend to be more highly ordered with more detailed spectra than the silicate rich compositions.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

1976 ◽  
Vol 32 ◽  
pp. 343-349
Author(s):  
Yu.V. Glagolevsky ◽  
K.I. Kozlova ◽  
V.S. Lebedev ◽  
N.S. Polosukhina
Keyword(s):  
Chemical Composition ◽  
Spectral Line ◽  
Variable Star ◽  
Radial Velocities ◽  
Crimean Astrophysical Observatory ◽  
Line Intensities ◽  
Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

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