Chemical Composition and Classification of Selected Steels

Keyword(s):  
2019 ◽  
Vol 11 (16) ◽  
pp. 141
Author(s):  
Larissa O. Fassio ◽  
Marcelo R. Malta ◽  
Gladyston R. Carvalho ◽  
Antônio A. Pereira ◽  
Ackson D. Silva ◽  
...  

This work aimed to characterize and discriminate genealogical groups of coffee as to the chemical composition of the grains through the model created by PLS-DA method. 22 accessions of Coffea arabica, from the Active Germplasm Bank of Minas Gerais, were divided into groups according to the genealogical origin. Samples of ripe fruits were harvested selectively and processed by the wet method, to obtain pulped coffee beans, with 11% (b.u.) of water content. The raw beans were assessed as to the content of polyphenols, total sugars, total lipids, protein, caffeine, sucrose, and fatty acids. The data were submitted the chemometric analysis, PCA and PLS-DA. The results of PLS-DA identified the variables which most influence the classification of genealogical groups and possible chemical markers to accessions processed by the pulped method. The sucrose content was an important marker for the Exotic accession group. However, the content of polyphenols has been identified as a marker for the group Tymor Hybrid, and the caffeine for the bourbon group. The different fatty acids have been identified as markers for all genealogical groups, at different levels. The model PLS-DA is effective in discriminating genealogical groups from the chemical composition of the beans.


Author(s):  
H.A. Lechevalier ◽  
Mary P. Lechevalier ◽  
Nancy N. Gerber
Keyword(s):  

Author(s):  
М.Л. Скрябин

Стальные отливки на сегодняшний день стали неотъемлемой частью современного литейного производства. В процессе получения отливок неизбежно появляются какие-либо дефекты. В данной работе рассмотрены причины образования дефектов при изготовлении отливок из стали 35ХГСЛ при литье по выплавляемым моделям. Также рассмотрены особенности отвода теплоты от отливки при первичной и вторичной кристаллизации. Приведена классификация зон отливок по ориентации кристаллов в отливках. Выявлена закономерность влияния интенсивности охлаждения на характер усадки. Today, steel castings have become an integral part of modern foundry production. In the process of obtaining castings, any defects inevitably appear. In this paper, we consider the production reasons for the formation of defects in the manufacture of castings made of 35XGSL steel when casting on investment models. The features of heat removal from the casting during primary and secondary crystallization are also considered. The classification of casting zones by the orientation of crystals in castings is given. The regularity of the influence of the cooling intensity on the shrinkage character is revealed.


Clay Minerals ◽  
1982 ◽  
Vol 17 (2) ◽  
pp. 159-173 ◽  
Author(s):  
D. Proust

AbstractThe mineralogical and chemical changes of sheridanite were followed in different alteration horizons as weathering of its host amphibolite increased. Microscopic and microprobe analyses of phases produced in or around the chlorite allowed a classification of the different alteration stages relative to their position in the profile. In the unweathered rock, prehnite and a sericite—kaolinite assemblage appear to have formed at grain boundaries between chlorites and plagioclases. These represent low-pressure (PH2O < 2.5 ± 1 Kb) and low-temperature (320–360°C) metamorphic phases. In the saprock, where initial rock structure is still preserved, chlorites weather to a more or less regular mixed-layer chlorite-vermiculite. In the saprolite, large-grain (20 µm) vermiculite forms in the clayey zones (plasma) when rock structure is destroyed. The chemical composition of these newly-formed minerals is influenced by the original chlorites and mixed-layer minerals.


1992 ◽  
Vol 70 (7) ◽  
pp. 1384-1387 ◽  
Author(s):  
M. Jurzysta ◽  
S. Burda ◽  
W. Oleszek ◽  
M. Ploszynski ◽  
E. Small ◽  
...  

The presence of saponins and their aglycones (sapogenins) was surveyed in seeds of 33 species of Medicago (Fabaceae). The four major subsections of the largest taxonomic section of Medicago, section Spirocarpos, can generally be distinguished by presence and (or) absence of medicagenic acid and zanhic acid. The latter sapogenin was found only in three of the subsections of Spirocarpos and seems to reflect the phylogenetic recency of these groups within Medicago. The distribution of zanhic acid in combination with other considerations proved useful in establishing that Medicago granadensis seems to be the oldest species in subsection Intertextae. The saponin profile of Medicago hybrida, most recently assigned to section Medicago, strongly supports the placement of this species and its relative Medicago sufruticosa in a separate section. Hemolytic saponins proved to be much more common in those species of Medicago that retain their seeds permanently within the fruit compared with species that tend to scatter their seeds, possibly because the former can benefit more from the antiherbivorous and (or) allelopathic properties of the saponins. Key words: hemolytic saponins, chemotaxonomy, taxonomy, ecology, Medicago.


1983 ◽  
Vol 40 (2) ◽  
pp. 215-229 ◽  
Author(s):  
T. J. Mulligan ◽  
L. Lapi ◽  
R. Kieser ◽  
S. B. Yamada ◽  
D. L. Duewer

The elemental chemical composition of salmon vertebrae has been measured by X-ray spectroscopy for two mixtures of stocks. Classification of fish to stock based on this composition has an accuracy in the range of 80–95%. Information on the techniques used, X-ray fluorescence spectroscopy and pattern recognition analysis, is presented for a reader with no background in these areas. The advantages and limitations of this method of stock identification are discussed.Key words: X-ray spectroscopy, pattern recognition analysis, stocks, salmon, management


2018 ◽  
Vol 277 ◽  
pp. 80-89 ◽  
Author(s):  
Zynovii Malanchuk ◽  
Viktor Moshynskyi ◽  
Yevhenii Malanchuk ◽  
Valerii Korniienko

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.


Sign in / Sign up

Export Citation Format

Share Document