The usual operation of a conductometric sensor device requires of an external energy source (i.e. an embedded heater). In the last years, the Joule effect in the sensing material, the so called self-heating effect, offered and alternative method to provide this energy: the probing current (or voltage) applied to measure the sensor signal also serves to heat up the sensor active film. Here, evid...

Reliable values of thermal conductivity of thin films made of GaN and its alloys are important for further development of nitride technology due to the problem of self-heating in GaN-based power transistors and optical devices. Using the differential 3v technique we measured the thermal conductivity of AlxGa1−xN thin films (x=0 and 0.4) grown by the hydride vapor phase epitaxy. Thermal conducti...

The deployment of high power radio frequency waves in the ion cyclotron range constitutes an important operational facility in many plasma devices, including ITER. Not only for pure heating of the plasma, i.e. Ion Cyclotron Resonant Heating (ICRH), but also for the generation of non-inductive current through Ion Cyclotron Current Drive (ICCD). We concentrate on minority species heating scenario...

A self-healing, metal matrix composite reinforced by shape memory alloy wires is simulated using finite element analysis. A one-dimensional constitutive model for SMA behavior is implemented as a user-defined truss element in ABAQUS. The matrix is brittle and a mode I crack is allowed to propagate through the specimen upon loading. During the loading process the wires undergo a martensitic phas...

We report results of the analytical and numerical investigation of self-heating effects in GaN-based high-power field-effect transistors. The problem of heat transfer in a transistor structure has been solved both analytically, using the method of images, and numerically. Two-dimensional electrothermal simulations of the GaN metal-semiconductor field-effect transistors on SiC and sapphire subst...

We analyze the high-temperature continuous-wave performance of 1.3m AlGaInAs/InP laser diodes grown by digital alloy molecular-beam epitaxy. Commercial laser software is utilized that self-consistently combines quantum-well bandstructure and gain calculations with two-dimensional simulations of carrier transport, wave guiding, and heat flow. Excellent agreement between simulation and measuremen...

In this paper, a nanosecond LIFT process is analyzed both from experimental and modeling points of view. Experimental results are first presented and compared to simple estimates obtained from physical analysis, i.e. energy balance, jump relations and analytical pocket dynamics. Then a self-consistent 2D axisymmetric modeling strategy is presented. It is shown that data accessible from experime...

Fuel cell polarisation performance is typically reported under controlled/constant temperature conditions, as a sign of robust metrology. However, in practice, fuel cells self-heat they generate current; which varies the across curve and affects performance. More detail regarding internal operation can be gleaned by current distribution mapping. For case an unheated cell, ‘self-heating’ increas...