Self-heating in the decomposition of 3-methyl-3-chlorodiazirine: determination of reaction exothermicity and correction of arrhenius parameters

1976 ◽  
Vol 72 (0) ◽  
pp. 1448 ◽  
Author(s):  
Wendy H. Archer ◽  
Brian J. Tyler
Keyword(s):  
Arrhenius Parameters ◽  
Self Heating

scholarly journals Characterization of Self-Heating Process in GaN-Based HEMTs

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1305 ◽  
Author(s):  
Daniel Gryglewski ◽  
Wojciech Wojtasiak ◽  
Eliana Kamińska ◽  
Anna Piotrowska
Keyword(s):  
Communication Systems ◽  
Accurate Determination ◽  
Heating Process ◽  
Equivalent Circuits ◽  
High Electron ◽  
Thermal Impedance ◽  
Self Heating ◽  
Gan Hemt

Thermal characterization of modern microwave power transistors such as high electron-mobility transistors based on gallium nitride (GaN-based HEMTs) is a critical challenge for the development of high-performance new generation wireless communication systems (LTE-A, 5G) and advanced radars (active electronically scanned array (AESA)). This is especially true for systems operating with variable-envelope signals where accurate determination of self-heating effects resulting from strong- and fast-changing power dissipated inside transistor is crucial. In this work, we have developed an advanced measurement system based on DeltaVGS method with implemented software enabling accurate determination of device channel temperature and thermal resistance. The methodology accounts for MIL-STD-750-3 standard but takes into account appropriate specific bias and timing conditions. Three types of GaN-based HEMTs were taken into consideration, namely commercially available GaN-on-SiC (CGH27015F and TGF2023-2-01) and GaN-on-Si (NPT2022) devices, as well as model GaN-on-GaN HEMT (T8). Their characteristics of thermal impedance, thermal time constants and thermal equivalent circuits were presented. Knowledge of thermal equivalent circuits and electro–thermal models can lead to improved design of GaN HEMT high-power amplifiers with account of instantaneous temperature variations for systems using variable-envelope signals. It can also expand their range of application.

Determination of off-gassing and self-heating potential of wood pellets – Method comparison and correlation analysis

Fuel ◽  
2018 ◽  
Vol 234 ◽  
pp. 894-903 ◽  
Author(s):  
Irene Sedlmayer ◽  
Mehrdad Arshadi ◽  
Walter Haslinger ◽  
Hermann Hofbauer ◽  
Ida Larsson ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Method Comparison ◽  
Wood Pellets ◽  
Self Heating

Compensation of Self-Heating in the Measurement of the Dynamic Response of a Thermoresistive Sensor

1997 ◽  
Vol 119 (3) ◽  
pp. 225-228 ◽  
Author(s):  
J. S. R. Neto ◽  
G. S. Deep ◽  
R. C. S. Freire ◽  
A. M. N. Lima ◽  
P. C. Lobo
Keyword(s):  
Heat Transfer ◽  
Response Time ◽  
Experimental Determination ◽  
Electrical Current ◽  
Theoretical Method ◽  
Optimal Choice ◽  
Self Heating ◽  
Ohmic Resistance ◽  
Measured Response

In the experimental determination of the response time of a thermoresistive sensor to a radiation step, one needs to monitor the variation of the ohmic resistance of the sensor with time. This requires passing electrical current through the sensor, which introduces error in the measured response time due to the additional self-heating of the sensor by the electrical current. A theoretical method to eliminate this error is formulated and experimental results are presented. The proposed method also permits experimental determination of the heat capacity (mc) and heat transfer coefficient (UA). The sensitivity analysis of τ = mc/UA permits the optimal choice for the resistance measurement currents.

scholarly journals Rapid determination of the high cycle fatigue properties of high temperature aeronautical alloys by self-heating measurements

2018 ◽  
Vol 165 ◽  
pp. 22022
Author(s):  
Vincent Roué ◽  
Cédric Doudard ◽  
Sylvain Calloch ◽  
Frédéric Montel ◽  
Quentin Pujol D’Andrebo ◽  
...  
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
High Cycle Fatigue ◽  
Rapid Determination ◽  
The Self ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Heating Method ◽  
Self Heating

The determination of high cycle fatigue (HCF) properties of a material with standard method requires a lot of specimens, and could be really time consuming. The self-heating method has been developed in order to predict S–N–P curves (i.e., amplitude stress – number of cycles to failure – probability of failure) with only a few specimens. So the time-saving advantage of this method has been demonstrated on several materials, at room temperature. In order to reduce the cost and time of fatigue characterization at high temperature, the self-heating method is adapted to characterize HCF properties of a titanium alloy, the Ti-6Al-4V (TA6V), at different temperatures. So the self-heating procedure is adjusted to conduct tests with a furnace. Two dissipative phenomena can be observed on self-heating curves. Because of this, a two-scale probabilistic model with two dissipative mechanisms is used to describe them. The first one is observed for low amplitudes of cyclic loading, under the fatigue limit, and the second one for higher amplitudes where the mechanisms of fatigue damage are activated and are dissipating more energy. This model was developed on steel at room temperature. Even so, it is used to describe the self-heating curves of the TA6V at several temperatures.

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