scholarly journals Characterization of Multiphase Oxide Layer Formation on Micro and Nanoscale Iron Particles

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 12
Author(s):  
Elena V. Zakharova ◽  
Ella L. Dzidziguri ◽  
Elena N. Sidorova ◽  
Andrey A. Vasiliev ◽  
Ivan A. Pelevin ◽  
...  

The article presents a detailed study and characterization of the oxide layers on the surface of iron particles of various sizes. Ten iron samples with a size range from a few nm to 50 µm were studied in detail using SEM, TEM, XRD, and TGA analysis. The composition of the multiphase oxide layers on the powder surface was investigated. The main components of the oxide layer were FeO, Fe3O4, and Fe2O3. By the obtained data, a model for the calculation of a multiphase oxide layer thickness on the surface of iron particles was proposed. The proposed model was validated and can be used for the characterization and certification of micro– and nanoscale iron particles.

1994 ◽  
pp. 65-68
Author(s):  
T. Uchikoshi ◽  
Y. Sakka ◽  
M. Yoshitake ◽  
T. Furubayashi ◽  
K. Yoshihara

2019 ◽  
Vol 492 ◽  
pp. 280-284
Author(s):  
Naoya Miyauchi ◽  
Tomoya Iwasawa ◽  
Taro Yakabe ◽  
Masahiro Tosa ◽  
Toyohiko Shindo ◽  
...  

2012 ◽  
Vol 23 (5) ◽  
pp. 539-546 ◽  
Author(s):  
Carlos Estrela ◽  
Manoel Damião Sousa-Neto ◽  
Orlando Aguirre Guedes ◽  
Ana Helena Gonçalves Alencar ◽  
Marco Antonio Hungaro Duarte ◽  
...  

Root perforation represents an undesirable complication that may lead to an unfavorable prognosis. The aims of this study were to characterize and to compare the presence of calcium oxide (CaO) on the chemical composition of materials used for root perforation therapy: gray and white mineral trioxide aggregate (MTA) and Portland cement (PC), gray MTA+5%CaO and gray MTA+10%CaO. The last two materials were analyzed to evaluate the increase of CaO in the final sample. CaO alone was used as a standard. Eighteen polyethylene tubes with an internal diameter of 3 mm and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37ºC. The chemical compounds (particularly CaO) and the main components were analyzed by energy-dispersive X-ray microanalysis (EDX). EDX revealed the following concentrations of CaO: gray MTA: 59.28%, white MTA: 63.09%; PC: 72.51%; gray MTA+5%CaO: 63.48% and gray MTA+10%CaO: 67.55%. The tested materials presented different concentrations of CaO. Even with an increase of 5 and 10% CaO in gray MTA, the CaO levels found in the MTA samples were lower than those found in PC.


DYNA ◽  
2019 ◽  
Vol 86 (210) ◽  
pp. 98-107
Author(s):  
Luz Marina Flórez Pardo ◽  
Andrea González Córdoba ◽  
Jorge Enrique López Galán

In this research, the types of hemicellulose that predominate in the leaves and tops of the three most cultivated varieties (CC 8475, CC 8592, V 7151) of sugarcane (Saccharum officinarum L.) in Valle del Cauca, Colombia were determined. Hemicellulose analyses were performed after delignification with sodium chlorite and extraction with 18% NaOH and 24% KOH containing 0.26 M NaBH4. The main components of hemicellulose were identified via FTIR and NMR spectroscopy, and monomeric sugars were identified via HPLC. Hemicellulose A composed of arabinoxylans, glucomannans and arabinogalactactans and hemicellulose B primarily composed of arabinoxylans were extracted. The hemicelluloses of the Colombian varieties were more stable against heat than those of the Venezuelan variety. The results of this project allowed discovery of the potential use of agricultural sugarcane residues for bioethanol production because they have a holocellulose content of more than 60%.


1981 ◽  
Vol 11 ◽  
Author(s):  
George G. Wicks ◽  
Barbara M. Robnett ◽  
W. Duncan Rankin

Leachability is one of the most important properties of solidified nuclear waste forms because it provides information on the performance and the subsequent safety and reliability that the waste products will possess. One of the most important experimental findings in the leachability field has been the discovery and subsequent detailed characterization of protective surface layers that form on waste glass during leaching. These layers can have a beneficial effect on product performance while in storage by improving productdurability with time. As a result of surface layer formation and the effects on subsequent product leaching characteristics, new qualitative and quantitative leaching models have recently been proposed.


2009 ◽  
Vol 56 (2) ◽  
pp. 799-803 ◽  
Author(s):  
Kenji Okuno ◽  
Sachiko Suzuki ◽  
Hirotada Ishikawa ◽  
Takumi Hayashi ◽  
Toshihiko Yamanishi ◽  
...  

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