Computer Modeling of the Process of Synthesis of Porous Glass-Composite Materials

2019 ◽  
Vol 945 ◽  
pp. 975-980
Author(s):  
L.A. Yatsenko ◽  
Elena A. Yatsenko ◽  
B.M. Goltsman
Keyword(s):  
Experimental Data ◽  
Heat Treatment ◽  
Computer Simulation ◽  
Pore Formation ◽  
Laboratory Experiments ◽  
Foam Glass ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Glass Composite ◽  
Computer Simulation Program

The operational properties of thermal insulation materials directly depend on their structure. The processes of pore formation occur inside the material after high-temperature treatment, which makes their studying more expensive and complicated. On the basis of experimental data, a computer simulation program for the process of pore formation has been developed, which makes it possible to simulate the processes of changing the structure of foam glass during heat treatment without repeated laboratory experiments.

Reduction of hardseededness in mungbean by short duration high temperature treatment

1992 ◽  
Vol 32 (4) ◽  
pp. 483 ◽  
Author(s):  
BC Imrie
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Short Duration ◽  
Vigna Radiata ◽  
Pilot Trial ◽  
Rotating Cylinder ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Hot Plate ◽  
Hard Seeds

Seeds of 2 lines of mungbean (Vigna radiata), soft-seeded cv. Berken and HS23 with 34% hard seeds, were agitated on a hot plate to determine the effects of temperatures up to 200�C on hardseededness, germination and seed variability. The results of this experiment, combined with a pilot trial using a heated rotating cylinder, showed that the temperature of 175�C for 30 s was the optimum treatment to produce seeds suitable for sprouting. This heat treatment reduced hardseededness from 34 to 1%, increased germination from 64 to 96%, and did not increase the percentage of dead seeds.

A modified ultra high temperature treatment for reducing microbial lipolysis in stored milk

1987 ◽  
Vol 54 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Anthony R. Bucky ◽  
Patrick R. Hayes ◽  
David S. Robinson
Keyword(s):  
Heat Treatment ◽  
Fatty Acids ◽  
High Temperature ◽  
Free Fatty Acids ◽  
Storage Period ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Viable Cells ◽  
Whole Milk ◽  
Ultra High Temperature

SummaryCultures ofPseudomonasP46 grown in whole milk to contain ∼ 2 × 107or 1 × 108viable cells ml−1before ultra high temperature (UHT) treatment (140°C for 5 s) demonstrated near linear increases in the concentration of short-chain free fatty acids (FFA) during storage at 20°C. However with 5 × 106cells ml−1before UHT heat treatment there was no detectable increase in these FFA levels over a 6-month storage period. A novel heat treatment (140°C for 5 s followed by 60°C for 5 min) reduced the rate of production of volatile FFA to < 10% of the rates achieved after the normal UHT treatment.

Effect of Structure on the Mechanical Properties of PAN-Based Carbon Fibers during Graphitization

2011 ◽  
Vol 686 ◽  
pp. 770-777 ◽  
Author(s):  
Hao Xiao ◽  
Yong Gen Lu ◽  
Xian Ying Qin ◽  
Ya Wen
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fiber Surface ◽  
Total Porosity ◽  
Interlayer Spacing ◽  
Temperature Treatment ◽  
Treatment Temperature ◽  
High Temperature Treatment ◽  
X Ray Diffraction ◽  
Crystallite Sizes

An investigation was conducted to determine the influence of high temperature treatment from 1600°C to 2800°C under stretching stress of 10MPa on PAN-based carbon fiber structure and physical properties. The tensile strength of fibers decreased from 4.5GPa to 2.97GPa with increasing treatment temperature up to 2800°C，while the modulus of fibers increased from 230GPa to 375GPa The texture in the longitudinal surface of fibers through heat treatment was characterized using a scanning electron microscopy. The contours of fiber surface became accidented with gaps becoming deeper as temperature increased. It has been observed that both the crystallite sizes (La, Lc) and the degree of preferred orientation increasd, while the crystallite interlayer spacing (d002) decreased by X-ray diffraction analysis with increasing heat-treatment temperature. The total porosity of fibers decreased from 21.01% to 15.09% and while the density of fibers increased from 1.720g/cm-3to1.886 g/cm-3with increasing heat-treatment. In addition, the relationship between mechanical properties and structure of variants was also explored in detail.

scholarly journals KINETICS OF STRUCTURAL TRANSFORMATIONS AT PORES FORMATION DURING HIGH-TEMPERATURE TREATMENT OF FOAM GLASS

2018 ◽  
Vol 14 (2) ◽  
pp. 158-168 ◽  
Author(s):  
Sergey V. Fedosov ◽  
Maksim O. Bakanov ◽  
Sergey N. Nikishov
Keyword(s):  
Foam Glass ◽  
Outer Boundary ◽  
Glass Structure ◽  
Three Dimensional ◽  
Spherical Shape ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Glass Charge ◽  
Growth Center ◽  
Kinetics Of

The work shows the key points used in the simulation of pores formation and growth in the foam glass structure. Pore is represented as a separate radius growth center with the outer boundary of a spherical shape and with a specified value of the initial radius surrounded by a finite volume of molten glass that is a part of foam glass charge stock. Solution of three-dimensional problem is reduced to one-dimensional setting in spherical coordinates. The presented model takes into consideration kinetics of pores radius growth, taking into account the influence of glass viscosity and surface tension, as well as the effect of moving (stretching) glass cladding when pores radius increases.

scholarly journals Role of acid-base interactions in synthesis of cordierite from talc and sillimanite group minerals

2013 ◽  
Vol 45 (3) ◽  
pp. 273-279 ◽  
Author(s):  
E.G. Avvakumov ◽  
G.G. Lepezin ◽  
A.A. Gusev ◽  
O.B. Vinokourova
Keyword(s):  
Heat Treatment ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Acid Base ◽  
Oxygen Ions ◽  
Limiting Step ◽  
Significant Acceleration ◽  
Rate Of Reaction ◽  
The Difference

It has been found that the mechanical activation of mixtures of sillimanite group minerals with talc and silica additives in grinding-activating devices with periodic and flow action provides significant acceleration of their interaction with formation of cordierite at the subsequent high-temperature treatment. It is shown that the output of cordierite depends on nature of mineral: in mixture with a sillimanite it is considerably higher, than with an andalusite and kyanite, while the rate of mullitization of these minerals has opposite character. It means that the formation of mullite during heat treatment is not a limiting step in synthesis of cordierite. It is shown that the rate of reaction is determined by the difference in the acid-base properties of these minerals, which depend on the coordination of aluminum cations by oxygen ions, different for each of the modifications.

scholarly journals Microstructure Characterization of Ni-Based Alloys for Packaging Application upon Long-Term Heat Treatment

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1159
Author(s):  
Jianbing Ren ◽  
Yilong Ma ◽  
Kejian Li
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Grain Size ◽  
Temperature Treatment ◽  
Working Environment ◽  
High Temperature Treatment ◽  
Surface Corrosion ◽  
Two Samples ◽  
Mo Content

In this study, an investigation was conducted to examine two types of Ni-based alloys upon long-term heat treatment and compare their grains, surface corrosion layers and microhardness values. The working environment of the tested samples was a temperature of 1000 °C for 5000 h. Two samples, respectively, contained low (~8 wt.%) and high (~16 wt.%) contents of Mo, and the low-Mo-content sample contained Nb (~4 wt.%) and other elements. The grains, precipitates, corrosion layers and microhardness values of the samples before and after heat treatment were determined by scanning electron microscopy, electron back-scattered diffraction, transmission electron microscopy, X-ray diffraction analysis and Vickers hardness tests. The results revealed that the grain was surprisingly stable in the sample with the higher Mo content; after heat treatment, the grain size was ~35 μm, which was similar to the grain size before heat treatment. Moreover, for the sample with the higher Mo content, the microhardness was found to be higher, especially after long-term high-temperature treatment, which is of great significance for the long service life of materials.

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