Temperature Dependance of Photocurrent Decay Times in Very High Resistivity, Zn-Compensated n-Type Silicon

1973 ◽  
Vol 51 (19) ◽  
pp. 2092-2100 ◽  
Author(s):  
V. Krishna ◽  
N. Rumin
Keyword(s):  
Experimental Data ◽  
Zinc Level ◽  
High Resistivity ◽  
Temperature Dependent ◽  
Material Constants ◽  
Decay Times ◽  
Temperature Dependance ◽  
Very High ◽  
Photocurrent Decay ◽  
Good Agreement

The photocurrent decay in high resistivity, n-type zinc-compensated silicon photoconductors has been measured in the temperature range 230–300 °K. The bulk portion of the decay can be resolved into two strongly temperature-dependent exponential components. A bulk recombination model based on two defect levels was used to analyze the experimental data. Reasonably good agreement between experiment and theory could be obtained only if the two centers were assumed to be the photoconductivity sensitizing, double acceptor Zn−3/2, and the V−3/2 level due to the vacancy which is also a double acceptor. In contrast, the measurements could only be partly explained with models in which the V−3/2 level was replaced by the E center, the lower zinc level Zn−1/2, or the A center. Moreover, unreasonable values for some of the material constants had to be assumed with these latter models.

scholarly journals Computer-Aided Arrhenius-Evaluation of Kinetic Data

1995 ◽  
Vol 50 (6) ◽  
pp. 549-554
Author(s):  
P. Hugo ◽  
J. Leonhardt ◽  
S. Wagner
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Kinetic Data ◽  
Evaluation Method ◽  
Arrhenius Law ◽  
Temperature Dependent ◽  
Dependent Part ◽  
Computer Aided ◽  
Temperature Programmed ◽  
Temperature Dependance

Abstract A new evaluation method is presented to analyse the temperature dependance of reactions with rates that can be separated into a temperature dependent and a concentration dependent part. The proposed method allows to evaluate isothermal, adiabatic, isoperibolic and temperature programmed measurements in an unified manner. To determine the activation energy an Arrhenius law but no explicite kinetic model has to be assumed. The application of the method is demonstrated using experimental data of different reactions from former investigations.

Modeling of TCP Muscles for Understanding Actuation Behavior

2017 ◽  
Author(s):  
Farzad Karami ◽  
Yonas Tadesse
Keyword(s):  
Good Accuracy ◽  
Coefficient Of Thermal Expansion ◽  
Linear Displacement ◽  
Experimental Result ◽  
Temperature Dependent ◽  
Length Changes ◽  
Thermal Stimuli ◽  
Thermal Part ◽  
Very High ◽  
Good Agreement

Twisted and Coiled Polymers (TCP) muscles are actuators that generate force and linear displacement in response to thermal stimuli. Their length changes significantly by heating due to a high negative coefficient of thermal expansion (CTE). A mathematical model for predicting the behavior of TCP muscles is essential for exploiting maximum advantage from these actuators and also controlling them. In this work, a simple, practical, and accurate model for predicting the displacement of TCP muscles, as a function of input electrical actuation and load, is derived. The problem is broken down into two, i.e. modeling of the thermal and thermo-elastic part. For the first part, a differential equation with changing electrical resistance term is derived. In the next step, by using a temperature-dependent modulus of elasticity and CTE as well as taking the geometry of muscles into account, an expression for displacement as a function of temperature and load is proposed. Experimental actuation data of a TCP muscle is used for verifying the model and investigating its accuracy. The thermal part shows a good agreement between the simulation and experimental result. The displacement part also has a good accuracy for medium and high actuation currents but there is a mismatch in very high current magnitudes. The cause of the discrepancy is explained and recommendations are made for the best performance of TCP muscles.

Simulation Model for Helical Rotor Expanders

1991 ◽  
Author(s):  
Larry D. Simmons
Keyword(s):  
Experimental Data ◽  
Computer Model ◽  
Phase Flow ◽  
Performance Potential ◽  
Nitrogen Gas ◽  
Two Phase ◽  
New Applications ◽  
Very High ◽  
Good Agreement ◽  
Fluid Characteristics

Abstract The objective of this project was to develop a computer model for the helical rotor expander which can be used to determine performance potential and to facilitate optimization of expander design. Testing has shown that this energy conversion device has substantial potential advantages over conventional turbines in very high temperature cycles and for two-phase flow. However, the tests have been limited to particular non-optimized designs, and a model is badly needed to assess viable design improvements and their effects on performance. A computer model was developed to simulate the geometric and thermal/fluid characteristics of the expander to give power output, mass flow rate, and efficiency versus rotational speed for any chosen design configuration. The model has been tested against experimental data from expanders running on nitrogen gas and two-phase steam with good agreement. It is now ready and available for use in developing and evaluating designs for new applications of the helical rotor expander.

Back shifted Fermi gas model with temperature dependent pairing energy: Thermal properties of 98Mo

2016 ◽  
Vol 25 (09) ◽  
pp. 1650065
Author(s):  
S. A. Alavi ◽  
V. Dehghani
Keyword(s):  
Experimental Data ◽  
Heat Capacity ◽  
Level Density ◽  
Fermi Gas ◽  
Nuclear Level Density ◽  
Temperature Dependent ◽  
Nuclear Level ◽  
Ginzburg Landau ◽  
The Mean ◽  
Good Agreement

The effect of using a temperature dependent pairing term in back-shifted Fermi-gas (BSFG) formula of nuclear level density has been studied. We have used the mean order parameter formula of modified Ginzburg–Landau (MGL) theory as a simple possible choice for temperature dependency of the pairing term. The level density and heat capacity of [Formula: see text]Mo have been calculated with this formalism and compared with the experimental data. We observed good agreement between the heat capacity of this model and the experimental data.

A Self-Consistent Scheme for the Relaxation Behavior of Metals

1981 ◽  
Vol 48 (4) ◽  
pp. 779-784 ◽  
Author(s):  
G. J. Weng
Keyword(s):  
Experimental Data ◽  
Relaxation Behavior ◽  
The Self ◽  
Combined Stress ◽  
Temperature Dependent ◽  
Free Process ◽  
Self Consistent ◽  
Temperature Environment ◽  
Stress Variations ◽  
Good Agreement

We identify in this paper that stress relaxation in metals is a “strain-free” process. The corresponding self-consistent relations between the strain, and stress variations of a grain and of its aggregate are derived from Eshelby’s solution of an ellipsoidal inclusion. It is shown that, under such a process, the strain in a more favorably oriented grain continues to rise and that its stress decreases more drastically than that of the aggregate; conversely, for a less favorably oriented grain, its strain decreases and its stress relaxes less. The self-consistent relations are supplemented with a temperature-dependent, physically consistent constitutive equation for the slip system. Such an equation enables us to determine the single crystal constants at one temperature from the polycrystal data at another temperature; it also makes the self-consistent scheme applicable to the varying-temperature environment. The established theory was finally applied to predict the relaxation behavior of an RR-59 aluminum alloy under combined stress; the results showed reasonably good agreement with the experimental data.

Analysis of fusion cross-sections of 6He, 8He and 11Li halo nuclei by using temperature-independent and temperature-dependent potentials

2019 ◽  
Vol 35 (04) ◽  
pp. 2050005
Author(s):  
M. Aygun
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Nuclear Physics ◽  
Halo Nuclei ◽  
Fusion Reactions ◽  
Temperature Dependent ◽  
Dependent Potential ◽  
Theoretical Results ◽  
Good Agreement

Analysis of the fusion reactions of halo nuclei is one of the important subjects of nuclear physics. In addition, temperature-dependent analysis of fusion cross-sections of these nuclei is a deficient topic in the literature. In order to overcome this deficiency, the fusion cross-sections of 6He, 8He and [Formula: see text]Li which are the most important halo nuclei are analyzed by using both temperature-independent potential and temperature-dependent potential. All the theoretical results are compared with each other as well as the experimental data. It is seen that the results of temperature-independent potential are in good agreement with the data while the temperature-dependent potential has a significant impact on the fusion cross-sections. Finally, the changes with the temperature of both real and nuclear potentials of all the reactions are investigated.

Calculations and Modeling of Material Constants in Hyperbolic-Sine Creep Model for 316 Stainless Steels

2013 ◽  
Vol 457-458 ◽  
pp. 185-190 ◽  
Author(s):  
Fu Qiang Yang ◽  
He Xue ◽  
Ling Yan Zhao ◽  
Jin Tian
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Creep Rate ◽  
Stainless Steels ◽  
Creep Model ◽  
Material Constants ◽  
316 Stainless Steel ◽  
Hyperbolic Sine ◽  
Predict Model ◽  
Good Agreement

The material constants calculation models for hyperbolic-sine creep model were proposed. The material constants used in hyperbolic-sine creep model for 316 stainless steel were calculated due to the models proposed and experimental data in the temperature range from 873K to 1023K. The relationships between material constants of 316 stainless steel creep model and temperature were obtained by curve fitting. The creep rate predict model of 316 stainless steel with only stress and temperature was also developed, the creep rates predicted were in good agreement with experimental data.

Electron Mobility In N-Type Epitaxial ZnSe

1990 ◽  
Vol 216 ◽  
Author(s):  
M. Vaziri ◽  
R. Reifenberger
Keyword(s):  
Experimental Data ◽  
Molecular Beam Epitaxy ◽  
Gaas Substrate ◽  
Molecular Beam ◽  
Impurity Scattering ◽  
Poor Agreement ◽  
Temperature Dependent ◽  
Ionized Impurity Scattering ◽  
Data Call ◽  
Good Agreement

ABSTRACTAn analysis of the temperature dependent mobility in lightly doped ZnSe epitaxial layers grown on a semi-insulating GaAs substrate by Molecular Beam Epitaxy is reported. Our results indicate that the temperature dependence of the mobility is in poor agreement with calculated values based on typical phonon and ionized impurity scattering mechanisms. Good agreement between theory and experimental data call be obtained by including a scattering term associated with the space-charge region surrounding defects.

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

Energy Levels and Electromagnetic Transition of 90-94mo Nuclei Using Ibm-1

2020 ◽  
pp. 149-152
Keyword(s):  
Experimental Data ◽  
Transition Probability ◽  
Energy Levels ◽  
Dynamical Symmetry ◽  
Interacting Boson Model ◽  
Excitation Energies ◽  
Electromagnetic Transition ◽  
Boson Model ◽  
Energy States ◽  
Good Agreement

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .

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