Weight loss and gas evolution during sintering of silicon nitride powders synthesized by silica reduction and imide decomposition

1998 ◽  
Vol 13 (12) ◽  
pp. 3468-3472 ◽  
Author(s):  
Yasuhiro Goto ◽  
Yoshiyuki Ohnuma
Keyword(s):  
Weight Loss ◽  
Silicon Nitride ◽  
Liquid Phase ◽  
High Temperatures ◽  
Low Temperatures ◽  
Gas Evolution ◽  
Small Weight ◽  
Large Weight ◽  
Weight Losses ◽  
Silica Reduction

The relationships among weight loss, gas evolution, and other changes during sintering were investigated for silicon nitride powders synthesized by silica reduction and imide decomposition. Small weight losses were detected for all powders at low temperatures (below 1400 °C), and large weight losses were found to occur for the silica-reduction powders at high temperatures (1400–1800 °C). Only CO was detected in the sampled gases during sintering, and CO evolution peaks were seen at around 900–1200 (broad), 1400, and 1600 °C. The main deposited material around the samples was SiO. The weight losses at low temperatures were thought to be caused by evaporation of residual binder or adsorbed substances. The main causes of the large weight losses at high temperatures were thought to be CO and SiO evolutions, and CO evolution at around 1600 °C probably originated from the liquid phase accompanied by α–Si3N4 to β–Si3N4 transformation.

Erosion Behavior of Silicon Nitride with Graded Microstructure

2005 ◽  
Vol 287 ◽  
pp. 416-420
Author(s):  
Dae Soon Lim ◽  
Jong In Park ◽  
Dong Phill Lim ◽  
Byung Dong Han ◽  
Dong Soo Park
Keyword(s):  
Weight Loss ◽  
Grain Size ◽  
Thermal Properties ◽  
Silicon Nitride ◽  
High Temperatures ◽  
Depth Profile ◽  
Erosion Rate ◽  
Mechanical And Thermal Properties ◽  
Erosion Behavior ◽  
Auger Depth Profile

Silicon nitride has been considered as candidate tribological material due to their excellent mechanical and thermal properties. This study investigated the effect of graded grain size on the erosion behavior of silicon nitride at room and high temperatures. Erosion tests were carried out with a gas blast-type erosion tester at temperatures up to 800 °C. Weight loss after impact of SiC particles were measured. The erosion rate varied with temperature and microstructure. Different erosion behavior depending on microstructure were discussed based on SEM observation Auger depth profile of worn surfaces.

THE PHOTOLYSIS OF ACETONE IN THE LIQUID PHASE: THE GASEOUS PRODUCTS

1955 ◽  
Vol 33 (8) ◽  
pp. 1304-1315 ◽  
Author(s):  
R. Pieck ◽  
E. W. R. Steacie
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
High Temperatures ◽  
Low Temperatures ◽  
Excited Molecule ◽  
Quantum Yields ◽  
Cage Effect ◽  
Gaseous Products ◽  
Ethane Formation ◽  
Liquid Acetone

An investigation has been made of the photolysis of liquid acetone in the temperature range from 55° to −25 °C. The quantum yields of all products are small, and decrease strongly with decreasing temperature. It is concluded that the low yields can be explained both on the basis of the 'cage effect', and by the deactivation of an excited molecule. At high temperatures and intensities the gaseous products can be accounted for on the assumption that radicals have escaped from the 'cage' and react analogously to the gas-phase mechanism. At low temperatures ethane formation in the 'cage' may be of importance.

LABORATORY STUDIES ON MICROFUNGI ISOLATED FROM THE STEMS OF LIVING LODGEPOLE PINE, PINUS CONTORTA DOUGL.

1961 ◽  
Vol 39 (6) ◽  
pp. 1373-1385 ◽  
Author(s):  
R. J. Bourchier
Keyword(s):  
Weight Loss ◽  
Pinus Contorta ◽  
Malt Agar ◽  
Laboratory Studies ◽  
Agar Culture ◽  
Small Weight ◽  
Pine Wood ◽  
Weight Losses ◽  
No Weight Loss ◽  
Lodgepole Pines

Fungus isolation attempts, made from samples taken at 2-ft intervals in the stems of 40 lodgepole pines (Pinus contorta Dougl.), gave 1362 cultures. Sample trees were located at two sites and averaged 82.5 and 63.9 years of age. In malt agar culture Tympanis hypopodia Nyl. and the Coryne sarcoides complex were slightly antagonistic to Stereum pini (Schleich. ex Fr.) Fr. Both microfungi caused small weight losses in pine wood blocks and, when inoculated in advance on test blocks, reduced the decay caused by S. pini. Retinocyclus abietis (Crouan) Groves & Wells caused no weight loss but increased the decay attributable to S. pini. Tympanis hypopodia and C. sarcoides complex were more or less restricted to the lower heartwood of the trees. There was some evidence of a succession of fungi in the trees.

Low solubility of alumina in enstatite and uncertainties in estimated palaeogeotherms

1978 ◽  
Vol 288 (1355) ◽  
pp. 471-486 ◽  
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Alumina Content ◽  
Equilibrium Solubility ◽  
Low Solubility

Spurious kinks in estimated palaeogeotherms may result from small errors in the calibration of the geothermometers and geobarometers. New data indicate that the equilibrium solubility of alumina in enstatite is even less than shown by recent studies, and that the slopes (d T /d P ) of the isopleths of equal alumina content are steeper than hitherto believed. Consequently, pressures of equilibration estimated from current formulations of the orthopyroxene-garnet geobarometer will be too high at high temperatures (> 1200 °C) and too low at low temperatures.

scholarly journals Environmental temperature during early life affects the personality of mosquitofish in adulthood

2021 ◽  
Author(s):  
Haifeng Li ◽  
Xinyu ZHang ◽  
Yi Wu ◽  
Feng ZHang ◽  
CHunlin Li
Keyword(s):  
Body Length ◽  
High Temperatures ◽  
Low Temperatures ◽  
Early Life ◽  
Environmental Temperature ◽  
Phenotypic Trait ◽  
Behavioral Syndrome ◽  
Growing Up ◽  
Female Fish ◽  
Behavioral Traits

Abstract Personality has been observed in a variety of animal taxa with important implications in ecology and evolution. Exploring the influence of environmental temperature during early life on personality could help to understand the ontogeny of this phenotypic trait in animals. In this study, we reared newborn mosquitofish Gambusia affinis at high (30°C) and low (25°C) water temperatures and measured their shyness and exploration upon sexual maturity. We tested the repeatability of each behavioral trait; the correlation between them; and the effects of rearing temperature, sex, and body length on the behaviors. When growing up at low temperatures, female fish exhibited repeatability in shyness and exploration, and males exhibited marginal repeatability in shyness. However, neither of the 2 behaviors were repeatable when the fish were reared at high temperatures. There was a negative correlation between shyness and exploration, indicating that the 2 behaviors comprise a behavioral syndrome in this species. Mosquitofish reared at high temperatures were more explorative than those reared at low temperatures, while there was no difference in shyness between the 2 treatments. Body length and sex had no significant effects on the average values of the 2 behaviors. The results indicate that environmental temperature during early life could shape the personality of mosquitofish and modify the average of the behavioral traits. These findings might provide insights to understand the ontogeny of animal personality and how changes in environmental temperature influence animal dispersal by shaping their personality.

Effect of Weight Loss on Liquid-Phase-Sintered Silicon Carbide

2005 ◽  
Vol 80 (4) ◽  
pp. 1047-1052 ◽  
Author(s):  
Tor Grande ◽  
Hkon Sommerset ◽  
Eirik Hagen ◽  
Kjell Wiik ◽  
Mari-Ann Einarsrud
Keyword(s):  
Silicon Carbide ◽  
Weight Loss ◽  
Liquid Phase ◽  
Sintered Silicon

Analysis of Ferroelectric Microcapacitors by Scanning Probe Microscope

2004 ◽  
Vol 811 ◽  
Author(s):  
Nobuhiro Kin ◽  
Koichiro Honda
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Evaluation System ◽  
Ferroelectric Material ◽  
Scanning Probe Microscope ◽  
Scanning Probe ◽  
Electrical Heater ◽  
Device Processing ◽  
Probe Microscope ◽  
The Impact

ABSTRACTTo develop higher density FRAM requires reducing cell size. Therefore, the size effects resulting from device processing and the material's physical properties must be measured. Therefore, analyzing the electric characteristics of a single bit cell capacitor has become important. Two known characteristics of ferroelectric material are that the Vc increases at low temperatures, and the Pr falls at high temperatures. To further evaluate the impact of temperature on ferroelectrics, we constructed a new evaluation system based on a scanning probe microscope, that can measure the electric characteristics of a single bit cell capacitor. This system can be used in the temperature range from −120 degrees to 300 degrees C. We accomplished this by circulating liquid nitrogen around a SPM stage and by using an electrical heater. We measured the electrical properties of ferroelectric microcapacitors by using a sample with IrOx/PZT/Pt structure. Our measurements revealed that 2Pr really increases at low temperatures, and Pr decreases at high temperatures. That is, we have shown that Vc increases 30% at low temperatures and Pr decreases 10% also in an actual FRAM single bit cell capacitor.

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