The thermal field of an oil layer for phase transformations within a limited temperature range

2012 ◽  
Vol 50 (2) ◽  
pp. 265-272
Author(s):  
A. I. Filippov ◽  
K. K. Nandi ◽  
R. G. Fattakhov ◽  
T. A. Ishmuratov
Keyword(s):  
Phase Transformations ◽  
Thermal Field ◽  
Temperature Range ◽  
Limited Temperature ◽  
Limited Temperature Range

Reduction of binary sulfate mixtures containing CuSO4 by H2

1976 ◽  
Vol 54 (23) ◽  
pp. 3651-3657 ◽  
Author(s):  
Fathi Habashi ◽  
Shaheer A. Mikhail
Keyword(s):  
Intermediate Product ◽  
The Other ◽  
Temperature Range ◽  
Other Hand ◽  
First Case ◽  
Limited Temperature ◽  
Limited Temperature Range ◽  
The Individual

The reduction of a binary sulfate mixture cannot be predicted from the behavior of the individual components. Thus, while CuSO4 is reduced to Cu at 400 °C and NiSO4 is reduced to Ni3S2, the sulfate mixture yields Cu, Ni3S2, and Cu2S. Also while FeSO4 is completely stable in H2 at 400 °C, (Cu,Fe) SO4 yields Cu and Cu5FeS4. The formation of Cu2S in the first case and Cu5FeS4 in the second was unexpected. On the other hand, (Cu,Mn)SO4 is stable in H2 up to 550 °C although pure CuSO4 is completely reduced at 400 °C. CoSO4 also interferes when reduced in presence of CuSO4, while Na2SO4, MgSO4, Al2(SO4)3, ZnSO4, CdSO4 do not interfere within limited temperature range. Of these only Na2SO4 forms a complex sulfate with CuSO4. No Cu2SO4 was identified when CuSO4 was reduced in presence of other sulfates although it is an intermediate product during the reduction of pure CuSO4.

scholarly journals Phase Transitions and Local Polarity above TC in a PbZr0.87Ti0.13O3 Single Crystal

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 286
Author(s):  
Iwona Lazar ◽  
Andrzej Majchrowski ◽  
Andrzej Soszyński ◽  
Krystian Roleder
Keyword(s):  
Phase Transitions ◽  
Solid Solutions ◽  
Piezoelectric Materials ◽  
Temperature Range ◽  
Limited Temperature ◽  
Similar Chemical ◽  
Limited Temperature Range ◽  
Optical Dielectric ◽  
Top Seeded Solution Growth ◽  
First Time

Solid solutions of PbZr1−xTixO3 (PZT) are one of the most widely used piezoelectric materials with perovskite structure. Despite the decades of research, the phase diagram of PZT reported in 1971 has not been resolved yet. Recently, it turned out that single crystals of good quality of these solid solutions can be grown. By means of top-seeded solution growth (TSSG) technique, we succeeded to grow a single PbZr0.87Ti0.13O3 crystal. Hence, a partial verification of the diagram could be performed through investigations of the optical, dielectric, pyroelectric and elastic properties of this crystal, in a wide temperature range. The obtained results confirmed that the PbZr0.87Ti0.13O3 crystal undergoes a sequence of phase transitions, such as those observed in ceramics of similar chemical composition. However, additional anomalies of investigated physical properties were observed and discussed. Moreover, the influence of electric field on optical properties has been investigated for the first time and has proven the existence of local polar character of the phase above TC in a limited temperature range.

Controlled Growth of Germanium Nanowires via a Solid–Liquid–Solid (SLS) Mechanism

2012 ◽  
Vol 557-559 ◽  
pp. 523-529 ◽  
Author(s):  
Shih Fong Lee ◽  
Li Ying Lee ◽  
Yung Ping Chang
Keyword(s):  
Surface Density ◽  
High Surface ◽  
Average Diameter ◽  
Germanium Nanowires ◽  
Temperature Range ◽  
Au Film ◽  
Limited Temperature ◽  
Limited Temperature Range ◽  
Solid Liquid ◽  
Nano Wires

In this study, germanium nanowires (GeNWs) were grown directly on gold-evaporated germanium substrates by a solid-liquid-solid (SLS) mechanism in the temperature range 550°C- 650°C. The growth of GeNWs is very sensitive to the growth temperature and only in a limited temperature range (575°C-625°C) can GeNWs having excellent morphology and high surface density be successfully grown. These long, thin, and straight GeNWs have a high aspect ratio and are surrounded by an oxide layer. The composition of corresponding oxide layers is GeOx (x<2). As the thickness of Au film is decreased from 9 nm to 1 nm, the average diameter of GeNWs decreases from 119.3 nm to 38.5 nm. Our experimental results demonstrate that the diameter of germanium nano¬wires can be controlled by the thickness of Au metal film.

The effect of undercooling and Nd422 phase content on the nucleation of large Nd–Ba–Cu–O grains fabricated by top-seeded melt processing

1999 ◽  
Vol 14 (10) ◽  
pp. 3859-3863 ◽  
Author(s):  
N. Hari Babu ◽  
W. Lo ◽  
D. A. Cardwell ◽  
Y. Shi
Keyword(s):  
Melt Processing ◽  
Phase Content ◽  
Slow Cooling ◽  
Solidification Temperature ◽  
Growth Technique ◽  
Temperature Range ◽  
Limited Temperature ◽  
Peritectic Solidification ◽  
Limited Temperature Range ◽  
Single Grain

The nucleation and growth of NdBa2Cu3O7–δ (Nd123)–Nd4Ba2Cu2O10 (Nd422) single-grain composites in a controlled 1% O2 in N2 atmosphere were investigated in detail as a function of solidification temperature and Nd422 phase content using a top-seeded melt growth technique. A schematic process phase diagram in the peritectic solidification region of Nd–Ba–Cu–O (NdBCO) was constructed primarily from constant isothermal growth experiments at various temperatures for several compositions and used to fabricate large single-grain material by both isothermal and continuous slow cooling over a limited temperature range. The nucleation at the seed surface and subsequent growth of uniform grains was observed to depend critically on the controlled rate of grain growth and the temperature range over which solidification occurred.

A Transmission Electron Microscopical Investigation of Phase Transformations in TiNi

1980 ◽  
Vol 38 ◽  
pp. 340-341
Author(s):  
P. Moine ◽  
G. M. Michal ◽  
R. Sinclair
Keyword(s):  
Electron Microscopy ◽  
Phase Transformations ◽  
Applied Stress ◽  
Structural Changes ◽  
Microscopical Investigation ◽  
Temperature Range ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Diffraction Effects ◽  
Microscopy Images

Premartensitic effects in near equiatomic TiNi have been pointed out by several authors(1-5). These include anomalous contrast in electron microscopy images (mottling, striations, etc. ),diffraction effects(diffuse streaks, extra reflections, etc.), a resistivity peak above Ms (temperature at which a perceptible amount of martensite is formed without applied stress). However the structural changes occuring in this temperature range are not well understood. The purpose of this study is to clarify these phenomena.

Strengthening method of wheelset tires

2021 ◽  
pp. 51-54
Author(s):  
D.V. Glazunov ◽  
V.N. Krotov ◽  
E.Yu. Cherkesov
Keyword(s):  
Wear Resistance ◽  
Physical Properties ◽  
Rolling Stock ◽  
Performance Tests ◽  
Limited Temperature ◽  
Main Disadvantage ◽  
Limited Temperature Range ◽  
Component Content ◽  
Selection Of ◽  
Strengthening Method

The main ways to strengthen and increase the resourse of wheelset bandage as result of which it is determined that the most economical and quick-to-implement method is the use of tribotechnical materials are considered. The main disadvantage in using of tribotechnical materials is the limited temperature range of rolling stock operation is determined. Qualitative selection of anti-wear and heat-resistant additives, as well as binder is perfomed based on the physical properties required for tribotechnical materials and the range of component content in the lubricant is determined. The wear resistance of wheelset bands is increased by 28 % as result of performance tests.

scholarly journals The influence of pressure on the spontaneous ignition of inflammable gas-air mixtures - IV—methane-, ethane-, and propane-air mixtures

1936 ◽  
Vol 154 (881) ◽  
pp. 95-112 ◽  
Keyword(s):  
Critical Pressure ◽  
Spontaneous Ignition ◽  
Lower Range ◽  
Experimental Conditions ◽  
Temperature Range ◽  
Limited Temperature ◽  
Tentative Hypothesis ◽  
Temperature Ranges ◽  
Higher Temperature ◽  
Temperature And Pressure

In previous papers the results of investigations into the influence of varying initial pressures up to 15-20 atmospheres on the spontaneous ignition of mixtures with air of butane, iso -butane, pentane, and hexane were described. On the attainment of a critical pressure, which varied both with the hydrocarbon concerned and the composition of its mixture with air, the ignition points were always found to fall sharply from a higher temperature range above 500°C to a lower range at about 300°C. At pressures just exceeding the critical transition pressures ignition occurred at first only within limited temperature ranges which widened and ultimately merged with increasing pressure. The striking relationship between the behaviours of the hydrocarbons referred to under the experimental conditions and their “knocking” propensities in an engine was also indicated. While the data available were inadequate for drawing any final con­clusion as to the character of the phenomena referred to, a tentative hypothesis was advanced that while ignition in the higher temperature range pertains mainly to the thermal decomponents of intermedially formed compounds, ignition in the lower system occurs when temperature and pressure conditions favour the survival and further oxidation of such bodies, particularly aldehydes.

Sign in / Sign up

Export Citation Format

Share Document