scholarly journals Anomalously Strong Effect of the Ion Sign on the Thermochemistry of Hydrogen Bonded Aqueous Clusters of Identical Chemical Composition

2009 ◽  
Vol 10 (2) ◽  
pp. 507-517 ◽  
Author(s):  
Alexey Nadykto ◽  
Fangqun Yu ◽  
Anas Al Natsheh
Keyword(s):  
Chemical Composition ◽  
Identical Chemical Composition ◽  
Hydrogen Bonded

Ag2S2O8 meets AgSO4: the second example of metal–ligand redox isomerism among inorganic systems

2016 ◽  
Vol 45 (45) ◽  
pp. 18202-18207 ◽  
Author(s):  
Tomasz E. Gilewski ◽  
Piotr J. Leszczyński ◽  
Armand Budzianowski ◽  
Zoran Mazej ◽  
Adam Grzelak ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physicochemical Properties ◽  
Inorganic Systems ◽  
Redox Isomerism ◽  
First Time ◽  
Identical Chemical Composition ◽  
Metal Ligand

Ag(i)2S2O8 – prepared here for the first time – constitutes a redox isomer of the already known Ag(ii)SO4. These “electromers” have identical chemical composition but they differ in all important physicochemical properties.

Factors of strength increasing of metals produced by selective laser melting of powders

2019 ◽  
pp. 68-75 ◽  
Author(s):  
B. K. Barakhtin ◽  
A. S. Zhukov ◽  
V. V. Bobyr ◽  
I. V. Shakirov ◽  
P. A. Kuznetsov
Keyword(s):  
Chemical Composition ◽  
Selective Laser Melting ◽  
Mechanical Tests ◽  
Strength Characteristics ◽  
Strength Increase ◽  
Metal Powders ◽  
Laser Melting ◽  
Standard Samples ◽  
Ultrafine Grained ◽  
Identical Chemical Composition

Standard samples of metal powders of various chemical composition were made for mechanical tests by selective laser melting. The paper describes an increase in strength characteristics of all samples made by melting comparing with similar parameters of monolithic samples of identical chemical composition. It is established that ultrafine-grained structure and condensation of nanoparticles could be cosidered factors of strength increase.

Minerálne zloženie kryštalických vápencov z lokality Dobšiná - Kruhová (Slovenská republika)

2021 ◽  
Vol 29 (2) ◽  
pp. 285-296
Author(s):  
Peter Ružička ◽  
Pavol Myšľan ◽  
Tomáš Mikuš
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Amphibolite Facies ◽  
Western Carpathians ◽  
Lower Content ◽  
Mineral Association ◽  
Decomposition Processes ◽  
Identical Chemical Composition

Crystalline limestones containing fragments of amphibolites from the locality Dobšiná - Kruhová are part of the Klátov complex (Northern Gemericum, Western Carpathians). The colour of studied rocks is light grey with massive texture and granoblastic structure. Inhomogeneous mottled to breccia-like character of a crystalline limestones is caused by the presence of amphiboles in the studied rocks. The identified mineral association of crystalline limestones consists of calcite, amphiboles (pargasite, magnesio-hornblende, actinolite), clinopyroxenes (diopside), albite and titanite. Chemical zonation of amphiboles from the crystalline limestones and fragments of amphibolites have been studied in BSE imaging. Light grey BSE zone is represented by pargasite (with more Fe2+ up to 1.37 apfu and less Mg up to 2.26 apfu) and dark grey BSE zone is represented by magnesio-hornblend and actinolite (less Fe2+ 0.68 apfu in magnesio-hornblende; 0.62 apfu in actinolite and more Mg up to 3.30 apfu in magnesio-hornblende and up to 4.03 apfu in actinolite). Diopside has slightly higher content of Al (up to 0.13 apfu) and low content of Fe2+ (up to 0.17 apfu) with XMg ratio in the range 0.83 - 0.96. Chemical composition of albites is Ab91.12-98.21An1.52-5.12 with ortoclase component in the range 0.22 - 4.49 mol. %. Titanites from the amphibolite fragments and crystalline limestones have identical chemical composition (Ca up do 1.00 apfu, Si up to 0.97 apfu). Lower content of Ti (0.88 - 0.95 apfu) and higher content of F (up to 0.27 wt. %) and H2O (up to 0.38 wt. %) is present. In titanites not very significant (Al, Fe3+) + (OH, F) ↔ Ti + O substitution was also identified. We assume that pargasite and magnesio-hornblende are products of prograde etape of metamorphosis unlike actinolite which is product of retrograde etape of metamorphosis. Diopside was generated by dehydration and decomposition processes of magnesio-hornblende and pargasite in a high-temperature prograde regime of metamorphosis in the conditions of upper amphibolite facies. Calcite is chemically pure, presence of dolomite has not been confirmed.

scholarly journals Thoughts on the “missing link” between saltworks biology and solat salt quality

2013 ◽  
Vol 12 (4) ◽  
pp. 417-425
Keyword(s):  
Sodium Chloride ◽  
Chemical Composition ◽  
Biological Processes ◽  
Solar Salt ◽  
Missing Link ◽  
Osmotic Solutes ◽  
Identical Chemical Composition

Although solar salterns worldwide use seawater of identical chemical composition as the raw material for salt production, the size and quality of the halite crystals that precipitate in the crystallizer ponds is highly variable. Biological processes have been implicated to be responsible for the differences observed, but the “missing link” between saltworks biology and solar salt quality has never unequivocally been identified. This paper presents an overview of the different organic chemicals that are formed by the members of the microbial communities in saltern evaporation and crystallizer ponds as osmotic stabilizers as well as different compounds formed during further microbial metabolism of those osmotic solutes. Examination of the in situ concentrations and the possible role of glycerol, glycine betaine, ectoine, dihydroxyacetone, acetate, lactate, and other organic compounds failed to identify one or more compounds that may accumulate at concentrations high enough to significantly modify the formation of sodium chloride crystals in the salterns and to negatively influence the quality of the salt produced.

Growth of Eutectic Austenite in Free Graphite Cast Irons

2010 ◽  
Vol 457 ◽  
pp. 67-72 ◽  
Author(s):  
Graciela Leonor Rivera ◽  
Roberto Enrique Boeri ◽  
Jorge Antonio Sikora
Keyword(s):  
Cast Iron ◽  
Chemical Composition ◽  
Standard Procedure ◽  
Flake Graphite ◽  
Cast Irons ◽  
Graphite Morphology ◽  
Identical Chemical Composition ◽  
Morphology Changes

The present work investigates the growth of the eutectic austenite of hypereutectic free graphite cast irons of different graphite morphology. The study was based on the analysis of several samples obtained from a highly hypereutectic cast iron melt. A hypereutectic melt was used in order to ensure the absence of proeutectic austenite. With the aim of obtaining samples of different graphite morphology but nearly identical chemical composition, the melt was nodularized by using a standard procedure, and different samples were cast after various fading periods. Through this procedure, spheroidal, vermicular and flake graphite samples were obtained The results show that the eutectic austenite grows dendritically in all samples investigated. Nevertheless, significant differences were found in the size of the solidification units (grains) and in the microsegregation patterns as the graphite morphology changes from spheroidal to flake.

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.

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