Synthesis of Superconducting Perovskite by Coprecipitation of Hydroxides

1990 ◽  
Vol 180 ◽  
Author(s):  
I. Valente-Campion ◽  
P. Barboux ◽  
L. Mazerolles ◽  
D. Michel ◽  
R. Morineau ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Perovskite Phase ◽  
Water Solutions ◽  
Alcohol Water ◽  
Long Time ◽  
Coprecipitation Of Hydroxides

ABSTRACTThe synthesis of the superconducting perovskite YBa2Cu3O7 using hydroxides as starting precursors has been investigated. Hydroxides are homogeneously coprecipitated from mixed alcohol-water solutions without loss of barium. Upon heat-treatment the perovskite phase rapidly forms around 750°C. However, it remains tetragonal even after long time annealing in oxygen ambient. This is related to an unusual microtwinning in the (ac) plane.

Spectroscopic study of the state of titanium(III) ions in alcohol-water solutions

1984 ◽  
Vol 19 (5) ◽  
pp. 544-548 ◽  
Author(s):  
S. Ya. Kuchmii ◽  
A. V. Korzhak ◽  
A. I. Kryukov
Keyword(s):  
Spectroscopic Study ◽  
The State ◽  
Water Solutions ◽  
Alcohol Water

scholarly journals Effect of Heat Treatment on Rheological Properties of Bambangan (Mangifera pajang kosterm) Fruit Juice

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Jumardi Roslan ◽  
Hay Chye Ling ◽  
Mohd Dona Sintang ◽  
Suryani Saallah
Keyword(s):  
Heat Treatment ◽  
Rheological Properties ◽  
Fruit Juice ◽  
Market Potential ◽  
Pseudoplastic Fluid ◽  
Treatment Conditions ◽  
High Temperature Short Time ◽  
Long Time ◽  
Mild Temperature ◽  
Short Time

Bambangan (Mangifera pajang Kosterm) is an indigenous fruit that can be found in Borneo Island including Sabah and Sarawak (Malaysia), Kalimantan (Indonesia), and Brunei. Besides being freshly eaten, the pulp of bambangan fruit can be processed for juice production to expand its market potential. During the processing of fruit juice, the application of heat treatment such as pasteurization and sterilization might influence their rheological behavior. Thus, the present study aims to investigate the effect of heat treatment on the rheological properties of bambangan fruit juice (BFJ). The freshly squeezed BFJ was subjected to different heat treatment conditions; sterilization (121°C, 3 minutes), mild temperature long time (MTLT) pasteurization (65°C, 15 minutes), and high temperature short time (HTST) pasteurization (90°C, 1 minute). Rheological analysis of the heat-treated BFJ was performed using a rheometer at a shear rate ranging from 1 to 250 s-1 and a temperature between 5 °C to 70 °C. Pasteurization at 90 °C for 1 minute (HTST) was found to be the most suitable heat treatment for the BFJ. At this condition, the BFJ exhibited a non-Newtonian pseudoplastic fluid behavior (n < 1), fitted well with the Herschel-Bulkey model. The value of parameters obtained from Herschel-Bulkley equation for HTST treatment of bambangan juice were n= 0.83, k= 0.32 and yield stress= 3.96. The viscosity values of HTST bambangan juice at the temperature of 5, 20, 40 and 70 °C were 3.53, 2.33, 1.53 and 1.76 Pa.s respectively. This rheological information is of fundamental importance in optimizing equipment design, process control, and sensory evaluation.

scholarly journals Problems Accompanying Repairs of Chemical Equipment

2020 ◽  
pp. 13-19
Author(s):  
Edmund Tasak ◽  
Aneta Ziewiec
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Welded Joints ◽  
Chemical Equipment ◽  
Treatment Processes ◽  
Welding Technology ◽  
Long Time ◽  
Formation Of Cracks

The paper presents problems experienced during repairs of structures operated at high temperature for a long time. Research-related TOFD method-based ultrasonic tests revealed indications implying the presence of unacceptable imperfections in welded joints. Attempted repairs involving the use of welding methods proved ineffective as the welding and heat treatment processes resulted in the formation of cracks. The tests and analysis of the above-named issue revealed that the reason for repair-related problems lay in relaxation cracks triggered by excessively high stresses in the joints and improper parameters of heat treatment to which the steel of the boiler was subjected. The welding technology developed as a result of the study enabled the performance of the proper repair of related equipment and made it possible to re-start the production.

Origin of the Hydrogen Absorbed by Incoherent TiC Particles in Iron

2005 ◽  
Vol 475-479 ◽  
pp. 233-236 ◽  
Author(s):  
Kaneaki Tsuzaki ◽  
Fu Gao Wei
Keyword(s):  
Heat Treatment ◽  
Water Vapor ◽  
High Temperatures ◽  
Thermal Desorption ◽  
Hydrogen Absorption ◽  
Room Temperature ◽  
Trap Hydrogen ◽  
Thermal Desorption Spectrometry ◽  
Long Time

Hydrogen absorption of incoherent TiC particles that were once reported to be strong hydrogen traps in iron at room temperature was investigated by means of thermal desorption spectrometry (TDS). The results indicated that incoherent TiC particles in iron do not trap hydrogen at all at room temperature even they are cathodically charged for a long time. Only at high temperatures and in atmosphere containing hydrogen source, incoherent TiC particles can trap hydrogen. The origin of hydrogen trapped by incoherent TiC particles was justified to be water vapor in the atmosphere during heat treatment.

Atomic and molecular emission following fracture of alkali halides: A dislocation driven process

1991 ◽  
Vol 6 (1) ◽  
pp. 112-125 ◽  
Author(s):  
J.T. Dickinson ◽  
L.C. Jensen ◽  
S.C. Langford ◽  
J.P. Hirth
Keyword(s):  
Heat Treatment ◽  
Molecular Species ◽  
Neutral Particle ◽  
Alkali Halides ◽  
Time Intervals ◽  
Neutral Species ◽  
Free Surfaces ◽  
Alkali Atoms ◽  
Fracture Event ◽  
Long Time

During and following fracture of a number of materials, the emission of photons, electrons, ± ions, and neutral species are observed; these emissions are collectively known as fracto-emission. In this work, we present measurements of the neutral particle emission following fracture of two single crystal fcc alkali halides: NaCl and LiF. We observe no measurable emission attributable to release during the fracture event itself. However, after relatively long time intervals of ∼0.5–250 ms, we observe rapid bursts of alkali atoms, as well as molecular species which include NaCl and (LiF)n where n = 1,2,3. Bursts of alkali containing species also occur during loading prior to fracture and for unloaded specimens during heat treatment. We argue that these bursts are due to energetic emergence (“popout”) of dislocations at free surfaces.

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