A physics-based temperature-dependent SPICE model for the simulation of high temperature microwave performance of HBT's and experimental results

2002 ◽  
Author(s):  
V. Krozer ◽  
M. Ruppert ◽  
W.Y. Lee ◽  
J. Grajal ◽  
A. Goldhorn ◽  
...  
Keyword(s):  
High Temperature ◽  
Experimental Results ◽  
Temperature Dependent ◽  
Spice Model

Temperature Dependent Emissivity of Multilayers on Silicon

1997 ◽  
Vol 470 ◽  
Author(s):  
S. Abedrabbo ◽  
N. M. Ravindra ◽  
W. Chen ◽  
V. Rajasekhar ◽  
T. Golota ◽  
...  
Keyword(s):  
High Temperature ◽  
Spectral Range ◽  
Silicon Oxide ◽  
Oxide Thickness ◽  
Experimental Results ◽  
Spectral Transmittance ◽  
Temperature Dependent ◽  
Temperature Range ◽  
Extensive Analysis

ABSTRACTThe spectral transmittance, reflectance and emittance of silicon related materials and structures are measured simultaneously utilizing a spectral emissometer operating at near- and mid-IR spectral range and temperature range of 300 to 1500K. Several kinds of samples have been considered here: a) SiO2/Si with oxide in the thickness range of 653–5124A, b) SiO2/Si/ SiO2 with oxide thickness of 5000A on both front and back sides c)Multi-layers of SiO2/Si/ SiO2/poly-Si, with backside oxide of 1600A and 250A, respectively and d) separation by implantation of oxygen (SIMOX), with embedded oxide thickness of 4000A. An extensive analysis has been performed to interpret and compare the results obtained from these measurements.Concerning the SiO2/Si, we find that the experimental results are in accord with the sinusoidal relation of emissivity as a function of the silicon oxide thickness and hence the Applied Materials model. Experimental results on SiO2/Si/SiO2 are also presented here. For the multi-layers of SiO2/Si/SiO2/poly-Si, it is interesting to note that for temperatures above 600°C, the emissivity is independent of temperature and wavelength for the backside oxide thickness of 1600 and 250A. SIMOX measurements are presented as well. The Fiory model has been utilized extensively to investigate the high temperature emissivity data. The applications and limitations of this model are discussed.

scholarly journals Using Reverse Osmosis Membrane at High Temperature for Water Recovery and Regeneration from Thermo-Responsive Ionic Liquid-Based Draw Solution for Efficient Forward Osmosis

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 588
Author(s):  
Eiji Kamio ◽  
Hiroki Kurisu ◽  
Tomoki Takahashi ◽  
Atsushi Matsuoka ◽  
Tomohisa Yoshioka ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
High Temperature ◽  
Energy Saving ◽  
Osmotic Pressure ◽  
Reverse Osmosis ◽  
Forward Osmosis ◽  
Solution Temperature ◽  
Water Recovery ◽  
Temperature Dependent ◽  
Draw Solution

Forward osmosis (FO) membrane process is expected to realize energy-saving seawater desalination. To this end, energy-saving water recovery from a draw solution (DS) and effective DS regeneration are essential. Recently, thermo-responsive DSs have been developed to realize energy-saving water recovery and DS regeneration. We previously reported that high-temperature reverse osmosis (RO) treatment was effective in recovering water from a thermo-responsive ionic liquid (IL)-based DS. In this study, to confirm the advantages of the high-temperature RO operation, thermo-sensitive IL-based DS was treated by an RO membrane at temperatures higher than the lower critical solution temperature (LCST) of the DS. Tetrabutylammonium 2,4,6-trimethylbenznenesulfonate ([N4444][TMBS]) with an LCST of 58 °C was used as the DS. The high-temperature RO treatment was conducted at 60 °C above the LCST using the [N4444][TMBS]-based DS-lean phase after phase separation. Because the [N4444][TMBS]-based DS has a significantly temperature-dependent osmotic pressure, the DS-lean phase can be concentrated to an osmotic pressure higher than that of seawater at room temperature (20 °C). In addition, water can be effectively recovered from the DS-lean phase until the DS concentration increased to 40 wt%, and the final DS concentration reached 70 wt%. From the results, the advantages of RO treatment of the thermo-responsive DS at temperatures higher than the LCST were confirmed.

Experimental results of the Li-Pb-Pt system obtained by the high temperature drop calorimetry

2021 ◽  
pp. 115824
Author(s):  
S. Terlicka ◽  
A. Dębski ◽  
W. Gąsior ◽  
A. Fornalczyk ◽  
M. Saternus
Keyword(s):  
High Temperature ◽  
Temperature Drop ◽  
Experimental Results ◽  
Drop Calorimetry

scholarly journals Postheated Model of Confined High Strength Fibrous Concrete

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Kaleem A. Zaidi ◽  
Umesh K. Sharma ◽  
N. M. Bhandari ◽  
P. Bhargava
Keyword(s):  
High Temperature ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
High Strength ◽  
Fibre Volume ◽  
Experimental Results ◽  
Confined Concrete ◽  
Structural Safety ◽  
Stress Strain ◽  
Fibrous Concrete

HSC normally suffers from low stiffness and poor strain capacity after exposure to high temperature. High strength confined fibrous concrete (HSCFC) is being used in industrial structures and other high rise buildings that may be subjected to high temperature during operation or in case of an accidental fire. The proper understanding of the effect of elevated temperature on the stress-strain relationship of HSCFC is necessary for the assessment of structural safety. Further stress-strain model of HSCFC after exposure to high temperature is scarce in literature. Experimental results are used to generate the complete stress-strain curves of HSCFC after exposure to high temperature in compression. The variation in concrete mixes was achieved by varying the types of fibre, volume fraction of fibres, and temperature of exposure from ambient to 800°C. The degree of confinement was kept constant in all the specimens. A comparative assessment of different models on the high strength confined concrete was also conducted at different temperature for the accuracy of proposed model. The proposed empirical stress-strain equations are suitable for both high strength confined concrete and HSCFC after exposure to high temperature in compression. The predictions were found to be in good agreement and well fit with experimental results.

Experimental and Numerical Characterisation of the Cyclic Thermo-Mechanical Behaviour of a High Temperature Forming Tool Alloy

2009 ◽  
Author(s):  
Aditya Deshpande ◽  
Sean B. Leen ◽  
Thomas H. Hyde
Keyword(s):  
High Temperature ◽  
Life Prediction ◽  
Creep Behaviour ◽  
Material Constant ◽  
Superplastic Forming ◽  
Material Model ◽  
Future Application ◽  
Temperature Dependent ◽  
Rate Dependent ◽  
Nickel Chromium

This paper describes high temperature cyclic and creep relaxation testing and modelling of a high nickel-chromium material (XN40F) for application to the life prediction of superplastic forming (SPF) tools. An experimental test programme to characterise the high temperature cyclic elastic-plastic-creep behaviour of the material over a range of temperatures between 20°C and 900°C is described. The objective of the material testing is the development of a high temperature material model for cyclic analyses and life prediction of superplastic forming (SPF) dies for SPF of titanium aerospace components. A two-layer visco-plasticity model which combines both creep and combined isotropic-kinematic plasticity is chosen to represent the material behaviour. The process of material constant identification for this model is presented and the predicted results are compared with the rate-dependent (isothermal) experimental results. The temperature-dependent material model is furthermore applied to simulative thermo-mechanical fatigue (TMF) tests, designed to represent the temperature and stress-strain cycling associated with the most damaging phase of the die cycle. The model is shown to give good correlation with the test data, thus vindicating future application of the material model in thermo-mechanical analyses of SPF dies, for distortion and life prediction.

Effects of Thermal Exposure on Microstructure and Mechanical Properties of Ni Based Superalloy GTD111

2011 ◽  
Vol 275 ◽  
pp. 31-34 ◽  
Author(s):  
Han Sang Lee ◽  
Keun Bong Yoo ◽  
Doo Soo Kim ◽  
Jae Hoon Kim
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Operating Temperature ◽  
Rupture Strength ◽  
Mechanical Test ◽  
Thermal Exposure ◽  
Creep Rupture Strength ◽  
Material Degradation ◽  
Temperature Dependent ◽  
Hot Gas

The rotating components in the hot sections of land-based gas turbine are exposed to severe environment during several ten thousand hours at above 1100 oC operating temperature. The failure mechanism of the hot gas components would be accompanied by material degradation in the properties of high temperature and creep rupture strength. Many hot gas components in gas turbine are made of Ni-based superalloy because of their high temperature performance. In this work, we surveyed the time and temperature dependent degradation of Ni-based superalloy. We prepared the specimens from GTD111 that are exposed at 871 oC and 982 oC in 1,000 ~ 10,000 hours. We carried out the mechanical test and microstructural observation.

High-temperature-dependent optical properties of ZnO film on sapphire substrate

2008 ◽  
Vol 516 (6) ◽  
pp. 1137-1141 ◽  
Author(s):  
Chenghua Sui ◽  
Naibo Chen ◽  
Xiaojun Xu ◽  
Gaoyao Wei ◽  
Pinggen Cai ◽  
...  
Keyword(s):  
Optical Properties ◽  
High Temperature ◽  
Sapphire Substrate ◽  
Zno Film ◽  
Temperature Dependent
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