Analysis of methods for heating the lining of high-temperature aggregates

2021 ◽  
pp. 40-44
Author(s):  
E. V. Prikhod’ko
Keyword(s):  
High Temperature ◽  
Heating Rate ◽  
Temperature Stresses ◽  
Strength Limit

An analysis of the methods of increasing the temperature of the lining during its drying and heating is given. Three options for increasing the temperature are considered: the maximum possible heating rate at first and its further decrease, the average heating rate, and the minimum heating rate at first and further acceleration to the maximum. It is shown that in order to preserve the resulting temperature stresses, no higher than the strength limit of the material is more efficient, the heating option with the highest possible speed first and its further decline. Ill. 4. Ref. 11. 

Characteristics of Photosynthesis in Different Wheat Cultivars under High Light Intensity and High Temperature Stresses

2009 ◽  
Vol 34 (12) ◽  
pp. 2196-2201 ◽  
Author(s):  
Xue-Li QI ◽  
Lin HU ◽  
Hai-Bin DONG ◽  
Lei ZHANG ◽  
Gen-Song WANG ◽  
...  
Keyword(s):  
High Temperature ◽  
Light Intensity ◽  
High Light Intensity ◽  
High Light ◽  
Wheat Cultivars ◽  
Temperature Stresses

High Temperature Oxidation Behavior of Strucflural Siucides

1993 ◽  
Vol 322 ◽  
Author(s):  
C. E. Ramberg ◽  
P. Beatrice ◽  
K. Kurokawa ◽  
W. L. Worrell
Keyword(s):  
High Temperature ◽  
Metal Oxide ◽  
Heating Rate ◽  
High Temperature Oxidation ◽  
Oxidation Behavior ◽  
Preparation Method ◽  
Molybdenum Disilicide ◽  
Silica Layer ◽  
Temperature Oxidation ◽  
High Temperature Oxidation Behavior

AbstractThe factors which control the formation of a protective silica (SiO2) layer on structural silicides at high temperature are summarized. The thermodynamic and kinetic conditions under which both silica and a metal oxide can form are also described. Molybdenum disilicide (MoSi2) forms highly protective silica scales and has the best oxidation resistance at high temperatures. Although the preparation method has little influence, the heating rate and the structure of the silica layer have significant effects on the oxidation behavior of MoSi2.

Superfast Sintering of Nanocrystalline Y2O3 Ceramics

2009 ◽  
Vol 66 ◽  
pp. 100-103 ◽  
Author(s):  
Xia Zheng ◽  
Zheng Yi Fu ◽  
Jin Yong Zhang ◽  
Wei Min Wang ◽  
Hao Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
Heating Rate ◽  
Grain Growth ◽  
Combustion Temperature ◽  
Applied Pressure ◽  
The Self ◽  
Temperature Synthesis ◽  
High Temperature Synthesis ◽  
Chemical Furnace ◽  
Maximum Combustion Temperature

Dense nanocrystalline Y2O3 ceramics without grain growth have been successfully obtained by a new method, which is based on the self-propagating high temperature synthesis and quick pressing. A suitable self-propagating system with a maximum combustion temperature of 1350 °C and a heating rate of 1300 °C/min was chosen as a chemical furnace to supply the heat to densify nanocrystalline Y2O3. Dense samples without grain growth were obtained when the applied pressure was 120 MPa.

scholarly journals The Formation of the Oxides of Carbon by the Pyrolysis of Tobacco

1975 ◽  
Vol 8 (1) ◽  
Author(s):  
R. R. Baker
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
High Temperature ◽  
Low Temperature ◽  
Heating Rate ◽  
Temperature Region ◽  
High Temperature Region ◽  
Heating Rates ◽  
Carbon Oxides ◽  
Decomposition Reactions

AbstractFlue-cured Virginia tobacco has been heated in nitrogen and nitrogen/oxygen mixtures under flow conditions, and the rate of formation of carbon monoxide and carbon dioxide has been determined as a function of temperature, heating rate, and proportion of oxygen in the gas. When the tobacco is heated in nitrogen at heating rates comparable to those in a smouldering cigarette, 27 % of the carbon content of the tobacco is converted to carbon oxides. Both carbon oxides show two distinct formation regions: a low-temperature region (about 100°-450°C), and a high-temperature region (about 550°-900°C). These temperature limits are almost identical to those predicted from studies on the combustion coal of a cigarette burning in air. When tobacco, or the carbonaceous residue remaining after the pyrolysis experiments, is heated in nitrogen / oxygen mixtures, the total amount of carbon converted to carbon monoxide and carbon dioxide is independent of heating rate, but the relative proportions of the two oxides are strongly dependent on heating rate. At the lower heating rate, proportionally less carbon monoxide, and more carbon dioxide, is produced. Under oxidation conditions, about 70 % of both carbon oxides formed in the low-temperature region (100°-450°C) are produced by tobacco decomposition reactions, whereas in the high-temperature region about 10-20 % of the carbon monoxide, and 2-9 % of the carbon dioxide, are produced by tobacco decomposition.

scholarly journals Small RNA-mediated responses to low- and high-temperature stresses in cotton

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Qiongshan Wang ◽  
Nian Liu ◽  
Xiyan Yang ◽  
Lili Tu ◽  
Xianlong Zhang
Keyword(s):  
High Temperature ◽  
Small Rna ◽  
Temperature Stresses

scholarly journals Matematical modeling of the process of enlarging the austenitic grain during high-temperature heating of alloy structural steel

2019 ◽  
pp. 74-84
Author(s):  
V. A. Kukareko ◽  
B. M. Gatsuro ◽  
A. N. Grigorchik ◽  
A. N. Chichin
Keyword(s):  
High Temperature ◽  
Heating Rate ◽  
Grain Structure ◽  
Slow Heating ◽  
Case Hardening ◽  
Regression Equations ◽  
Impurity Atoms ◽  
Average Size ◽  
Case Hardening Steel

The influence of the heating rate of a typical case hardening steel 15KHGN2TA and 25KHGT on the growth of austenitic grain during long-term isothermal exposures at the high-temperature chemical-heat treatment was studied. It is shown that the change in the rate of heating case hardening steels in the temperature interval a®g transformations during chemical-thermal treatment has a significant impact on the process of growth of austenitic grains in them.Regression equations describing the dependence of the average size of austenitic grain on the heating rate, pre-annealing temperature and cementation temperature are obtained, which allow selecting the cementation modes of various steels. A phenomenological model describing the mechanism of formation and growth of austenitic grains in steels under heating at different speeds is developed.It is concluded that the slow heating of steels in the interval of phase a®g transformation contributes to the formation of a complex of small austenite grains separated by high angle boundaries with adsorbed on them by impurity atoms, which ensures higher resistance grain structure to coalescence and reduce the rate of migration of the boundaries during prolonged hightemperature austenization.

scholarly journals Untangling irrigation effects on maize water and heat stress alleviation using satellite data

2021 ◽  
Author(s):  
Peng Zhu ◽  
Jennifer Burney
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Surface Temperature ◽  
Temperature Stress ◽  
Land Surface ◽  
Grain Filling ◽  
High Temperature Stress ◽  
Temperature Stresses ◽  
Stress Alleviation ◽  
Irrigation Effects

Abstract. Irrigation has important implications for sustaining global food production, enabling crop water demand to be met even under dry conditions. Added water also cools crop plants through transpiration; irrigation might thus play an important role in a warmer climate by simultaneously moderating water and high temperature stresses. Here we use satellite-derived evapotranspiration estimates, land surface temperature (LST) measurements, and crop phenological stage information from Nebraska maize to quantify how irrigation relieves both water and temperature stresses. Our study shows that, unlike air temperature metrics, satellite-derived LST detects significant irrigation-induced cooling effect, especially during the grain filling period (GFP) of crop growth. This cooling is likely to extend the maize growing season, especially for GFP, likely due to the stronger temperature sensitivity of phenological development during this stage. The analysis also suggests that irrigation not only reduces water and temperature stress but also weakens the response of yield to these stresses. Specifically, temperature stress is significantly weakened for reproductive processes in irrigated crops. The attribution analysis further suggests that water and high temperature stress alleviation contributes to 65 % and 35 % of yield benefit, respectively. Our study underlines the relative importance of high temperature stress alleviation in yield improvement and the necessity of simulating crop surface temperature to better quantify heat stress effects in crop yield models. Finally, untangling irrigation effects on both heat and water stress mitigation has important implications for designing agricultural adaptation strategies under climate change.

Modeling of Cyclic Response of High Temperature Shape Memory Alloys Undergoing Viscoplastic Mechanisms

2010 ◽  
Author(s):  
George Chatzigeorgiou ◽  
Yves Chemisky ◽  
Dimitris C. Lagoudas
Keyword(s):  
High Temperature ◽  
Shape Memory Alloys ◽  
Thermal Cycling ◽  
Shape Memory ◽  
Heating Rate ◽  
Evolution Equations ◽  
Experimental Tests ◽  
Energy Potential ◽  
Slow Cooling ◽  
Cyclic Response

In this work we present a constitutive model for High Temperature Shape Memory Alloys (HTSMAs), where the appearence of viscoplastic mechanisms during transformation influences the cyclic response of the actuator performance. Based on previous models developed for conventional SMAs, a Gibbs free energy potential is defined and the evolution equations for forward, reverse transformation, plasticity occuring during transformation, retained martensite and viscoplasticity are properly chosen. The calibration of the model is achieved with the help of experimental tests performed on TiPdNi alloy. The transformation behavior of the material is calibrated using fast load biased thermal cycling tests at selected stress levels with fast cooling/heating rate. The viscoplastic behavior of the HTSMA is captured with creep and uniaxial tests at appropriate temperature levels. Predictions of the model are compared with load biased thermal cycling tests at slow cooling/heating rate, where viscoplastic strains are significant.

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