The stability of vitamin A in fortified palm olein during extended storage and thermal treatment

2017 ◽  
Vol 52 (8) ◽  
pp. 1869-1877 ◽  
Author(s):  
Dewi Kristina Natalia Silalahi ◽  
Dewi Yuliyanti ◽  
Monica da Silva ◽  
Isti Christianti ◽  
Karyanto Mulyono ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Vitamin A ◽  
Palm Olein ◽  
The Stability

Thermal Treatment as a Means of Improving the Stability of Earth Masses

Géotechnique ◽  
1958 ◽  
Vol 8 (4) ◽  
pp. 158-165 ◽  
Author(s):  
A. A. Beles ◽  
I. I. Stănculescu
Keyword(s):  
Thermal Treatment ◽  
The Stability

scholarly journals Carbonitration of a Tool for Pressing Stainless Steel Pipes

2020 ◽  
Vol 7 (2) ◽  
pp. C17-C21
Author(s):  
I. V. Ivanov ◽  
M. V. Mohylenets ◽  
K. A. Dumenko ◽  
L. Kryvchyk ◽  
T. S. Khokhlova ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Heat Resistance ◽  
Alkali Metals ◽  
Matrix Ring ◽  
High Hardness ◽  
Operating Conditions ◽  
Matrix Rings ◽  
Conventional Heat Treatment ◽  
The Stability

To upgrade the operational stability of the tool at LLC “Karbaz”, Sumy, Ukraine, carbonation of tools and samples for research in melts of salts of cyanates and carbonates of alkali metals at 570–580 °C was carried out to obtain a layer thickness of 0.15–0.25 mm and a hardness of 1000–1150 НV. Tests of the tool in real operating conditions were carried out at the press station at LLC “VO Oscar”, Dnipro, Ukraine. The purpose of the test is to evaluate the feasibility of carbonitriding of thermo-strengthened matrix rings and needle-mandrels to improve their stability, hardness, heat resistance, and endurance. If the stability of matrix rings after conventional heat setting varies around 4–6 presses, the rings additionally subjected to chemical-thermal treatment (carbonitration) demonstrated the stability of 7–9 presses due to higher hardness, heat resistance, the formation of a special structure on the surface due to carbonitration in salt melts cyanates and carbonates. Nitrogen and carbon present in the carbonitrided layer slowed down the processes of transformation of solid solutions and coagulation of carbonitride phases. The high hardness of the carbonitrified layer is maintained up to temperatures above 650 °C. If the stability of the needle-mandrels after conventional heat treatment varies between 50–80 presses, the needles, additionally subjected to chemical-thermal treatment (carbonitration) showed the stability of 100–130 presses due to higher hardness, wear resistance, heat resistance, the formation of a special surface structure due to carbonitration in melts of salts of cyanates and carbonates. Keywords: needle-mandrel, matrix ring, pressing, heat treatment, carbonitration.

Thermal stability of metalorganic compounds on volcanic olivine

2020 ◽  
Author(s):  
Joanna Brau ◽  
Marco Matzka ◽  
Philippe Schmitt-Kopplin ◽  
Norbert Hertkorn ◽  
Werner Ertel-Ingrisch ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Treatment ◽  
Tube Furnace ◽  
Stability Field ◽  
Secondary Phases ◽  
The Stability ◽  
The Individual ◽  
Gas Tight ◽  
Metalorganic Compounds ◽  
Thermal Stability Of

<p>Previously unknown class of metalorganic compounds revealed in meteorites [1] also found on the surfaces of silicate phases such as olivine, may have been involved in the emergence of life.  Here, the thermal stability of such organic compounds has been experimentally investigated under conditions which simulate those extant on the early Earth. We have studied olivines from the Hawaiian eruptions of 1959 and 2018. Individual mineral grains have been hand-picked to be free of secondary phases such as pyroxene or melt. We use a high temperature gas-tight tube furnace under CO-CO<sub>2</sub> gas mixture at temperatures ranging from 950°C to 1350°C and oxygen fugacity ranging from 10<sup>-12</sup> to 10<sup>-10 </sup>bar, within the stability field of olivine. The samples were contained in Pt crucibles and held for dwell times of 1 to 64 h. Quenching was performed by lifting the samples vertically out of the tube furnace. Using EPMA (electron microprobe analyzer) and RAMAN spectroscopy, we have mapped the state of the olivine samples. We observe that the composition of the individual mineral grains remains stable and homogeneous with thermal treatment. We are also investigating the role of impurities and cracks in the natural olivine and synthetic forsterite that might influence our study. The metalorganic cargo of these olivines has been analyzed using FT-ICR-MS (Fourier Transform ion cyclotron mass spectrometry). Preliminary results reveal systematic changes or organic molecular composition depending on time and heat of thermal treatment whose origins will be discussed.</p><p>[1] A. Ruf, B. Kanawati, N. Hertkorn, Q. Yin, F. Moritz, M. Harir, M. Lucio, B. Michalke, J. Wimpenny, S. Shilobreeva, B. Bronsky, V. Saraykin, Z. Gabelica, R. D. Gougeon, E. Quirico, S. Ralew, T. Jakubowski,  H. Haack, M. Gonsior, P. Jenniskens, N. W. Hinman, P. Schmitt-Kopplin. (2017) Previously unknown class of metalorganic compoundsrevealed in meteorites. PNAS 114 (2017) 2819-2824.</p>

scholarly journals The Stability of Carotene and Vitamin A in a Mixed Ration

1939 ◽  
Vol 18 (3) ◽  
pp. 179-187 ◽  
Author(s):  
R.M. Bethke ◽  
P.R. Record ◽  
O.H.M. Wilder
Keyword(s):  
Vitamin A ◽  
The Stability

Storage conditions and packaging greatly affects the stability of fortified wheat flour: Influence on vitamin A, iron, zinc, and oxidation

2018 ◽  
Vol 240 ◽  
pp. 43-50 ◽  
Author(s):  
Youna M. Hemery ◽  
Arnaud Laillou ◽  
Laura Fontan ◽  
Vincent Jallier ◽  
Regina Moench-Pfanner ◽  
...  
Keyword(s):  
Vitamin A ◽  
Wheat Flour ◽  
Storage Conditions ◽  
The Stability
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