Analysis of Measured I(V) Relations for Electron Emission from Insulating Diamond Films on Various SI Substrates

1999 ◽  
Vol 558 ◽  
Author(s):  
K. L. Jensen ◽  
A. Göhl ◽  
G. Müller
Keyword(s):  
Experimental Data ◽  
Transport Model ◽  
Diamond Films ◽  
Field Enhancement ◽  
Interface Roughness ◽  
Positive Slope ◽  
Si Substrates ◽  
Roughness Model ◽  
Minimum Number ◽  
Geometrical Field

ABSTRACTIn this work, we shall analyze the performance of a geometrical interface roughness model to estimate current from p-type silicon into insulating diamond and compare the performance of that model to experimental data. A minimum number of adjustable parameters are invoked. While the model qualitatively accounts for trends in the experimental data, in particular, the shift from negative to positive slope on a Fowler Nordheim plot of the I(V) data, it does so at the expense of demanding ellipsoid parameters that appear to be unreasonable. We therefore conclude that a simple geometrical field enhancement model of interface roughness is insufficient to account for the current observed, and thus the theory must be augmented by a more comprehensive electron transport model at the interface.

Parameter Determination for Chloride and Tritium Transport in Undisturbed Lysimeters during Steady Flow

1992 ◽  
Vol 23 (2) ◽  
pp. 89-104 ◽  
Author(s):  
Ole H. Jacobsen ◽  
Feike J. Leij ◽  
Martinus Th. van Genuchten
Keyword(s):  
Experimental Data ◽  
Unsaturated Flow ◽  
Transport Model ◽  
Time Moment ◽  
Breakthrough Curves ◽  
Coarse Sand ◽  
Retardation Factor ◽  
Parameter Determination ◽  
Model Parameters ◽  
Water Fraction

Breakthrough curves of Cl and 3H2O were obtained during steady unsaturated flow in five lysimeters containing an undisturbed coarse sand (Orthic Haplohumod). The experimental data were analyzed in terms of the classical two-parameter convection-dispersion equation and a four-parameter two-region type physical nonequilibrium solute transport model. Model parameters were obtained by both curve fitting and time moment analysis. The four-parameter model provided a much better fit to the data for three soil columns, but performed only slightly better for the two remaining columns. The retardation factor for Cl was about 10 % less than for 3H2O, indicating some anion exclusion. For the four-parameter model the average immobile water fraction was 0.14 and the Peclet numbers of the mobile region varied between 50 and 200. Time moments analysis proved to be a useful tool for quantifying the break through curve (BTC) although the moments were found to be sensitive to experimental scattering in the measured data at larger times. Also, fitted parameters described the experimental data better than moment generated parameter values.

scholarly journals Minimum Number of Experimental Data for the Thermal Characterization of a Hot Water Storage Tank

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4741
Author(s):  
María Gasque ◽  
Federico Ibáñez ◽  
Pablo González-Altozano
Keyword(s):  
Experimental Data ◽  
Water Temperature ◽  
Temperature Profile ◽  
Storage Tank ◽  
Water Storage ◽  
Hot Water ◽  
Experimental Temperature ◽  
Inlet Temperature ◽  
Water Storage Tank ◽  
Minimum Number

This paper demonstrates that it is possible to characterize the water temperature profile and its temporal trend in a hot water storage tank during the thermal charge process, using a minimum number of thermocouples (TC), with minor differences compared to experimental data. Four experimental tests (two types of inlet and two water flow rates) were conducted in a 950 L capacity tank. For each experimental test (with 12 TC), four models were developed using a decreasing number of TC (7, 4, 3 and 2, respectively). The results of the estimation of water temperature obtained with each of the four models were compared with those of a fifth model performed with 12 TC. All models were tested for constant inlet temperature. Very acceptable results were achieved (RMSE between 0.2065 °C and 0.8706 °C in models with 3 TC). The models were also useful to estimate the water temperature profile and the evolution of thermocline thickness even with only 3 TC (RMSE between 0.00247 °C and 0.00292 °C). A comparison with a CFD model was carried out to complete the study with very small differences between both approaches when applied to the estimation of the instantaneous temperature profile. The proposed methodology has proven to be very effective in estimating several of the temperature-based indices commonly employed to evaluate thermal stratification in water storage tanks, with only two or three experimental temperature data measurements. It can also be used as a complementary tool to other techniques such as the validation of numerical simulations or in cases where only a few experimental temperature values are available.

scholarly journals Validation of the thermal transport model used for ITER startup scenario predictions with DIII-D experimental data

2010 ◽  
Vol 51 (1) ◽  
pp. 013001 ◽  
Author(s):  
T.A. Casper ◽  
W.H. Meyer ◽  
G.L. Jackson ◽  
T.C. Luce ◽  
A.W. Hyatt ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thermal Transport ◽  
Transport Model

scholarly journals Моделирование проводимости Капицы через шероховатые интерфейсы между твердыми телами

2021 ◽  
Vol 63 (7) ◽  
pp. 982
Author(s):  
Б. Лю ◽  
В.И. Хвесюк ◽  
А.А. Баринов
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Transmission Coefficient ◽  
Wide Temperature Range ◽  
Acoustic Waves ◽  
Theoretical Method ◽  
Interface Roughness ◽  
Kapitza Conductance ◽  
Acoustic Mismatch ◽  
The Difference

In this work, we have formulated and solved the problem of determining the Kapitza conductance across the interface between two solids, taking into account the interface roughness. We use a modified acoustic mismatch model (AMM). The difference from the classic model is that the dispersion properties of acoustic waves are considered. A significant advantage of this model is that the theoretical prediction agrees well with experimental data over a wide temperature range: from 30K to more than 300K. Finally, a theoretical method with the statistical distribution of roughness profiles is used to determine the energy transmission coefficient across the interface.

The Control Of Intrinsic Stresses In Cvd Diamond Films With Multistep Processing

1995 ◽  
Vol 416 ◽  
Author(s):  
S. Nijhawan ◽  
S. M. Jankovsky ◽  
B. W. Sheldon
Keyword(s):  
Thermal Stresses ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Annealing Treatment ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Internal Stresses ◽  
Tensile Stresses ◽  
Si Substrates

ABSTRACTThe role of intrinsic stresses in diamond films is examined. The films were deposited on (100) Si substrates by microwave plasma-enhanced chemical vapor deposition. The total internal stresses (thermal and intrinsic) were measured at room temperature with the bending plate method. The thermal stresses are compressive and arise due to the mismatch in thermal expansion coefficient of film and substrate. The intinsic stresses were tensile and evolved during the deposition process. These stresses increased with increasing deposition time. A 12 hour intermediate annealing treatment was found to reduce the tensile stresses considerably. The annealing treatment is most effective when the diamond crystallites are undergoing impingement and coalescence. This is consistent with the theory that the maximum tensile stresses are associated with grain boundary energetics.

PEELS and EXELFS characterization of diamond films grown by the HF-CVD technique on non-scratched Si substrates

1997 ◽  
Vol 304 (1-2) ◽  
pp. 45-47 ◽  
Author(s):  
A. Duarte-Moller ◽  
O. Contreras ◽  
G.A. Hirata ◽  
M. Avalos-Borja ◽  
D.H. Galván ◽  
...  
Keyword(s):  
Diamond Films ◽  
Si Substrates

Measuring the Adhesion of Diamond Thin Films to Substrates Using the Blister Test

1995 ◽  
Vol 383 ◽  
Author(s):  
Jim Sizemore ◽  
R. J. Hohlfelder ◽  
J. J. Vlassak ◽  
W. D. Nix
Keyword(s):  
Thin Films ◽  
Test Data ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Simple Equation ◽  
Testing Technique ◽  
Blister Test ◽  
Plasma Enhanced Cvd ◽  
Si Substrates ◽  
Diamond Thin Films

ABSTRACTIt is shown that the blister testing technique can be used to measure the adhesion of thin films to their substrates. A brief discussion of blister test mechanics is presented here, leading to a simple equation relating adhesion to the height of the blister and the pressure causing it to grow. Blister test data for plasma-enhanced CVD diamond films on Si substrates have been analyzed using this relation. The tests show adhesion energies of 1.8– 2.6 J/m2.

Investigation on Field Electron Emission from Carbon Nanotubes on Nanocrystalline Diamond Films

2005 ◽  
Vol 23 ◽  
pp. 35-38 ◽  
Author(s):  
K.J. Liao ◽  
W.L. Wang ◽  
C. Cai ◽  
J.W. Lu ◽  
C.G. Hu
Keyword(s):  
Carbon Nanotubes ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Electron Field Emission ◽  
Si Substrates ◽  
Turn On ◽  
Nanocrystalline Diamond Films ◽  
Electron Field ◽  
Hot Filament

The electron field emission from carbon nanotubes on nanocrystalline diamond films was investigated. Carbon nanotubes and nano-diamond films were deposited on Si substrates by hot filament chemical vapor deposition. The experimental results showed that the carbon nanotubes on nanostructured films exhibited a lower value of the turn-on electric field than those of carbon nanotubes and nano-diamond. It was found that the turn-on field of nanotubes on nano-diamond was about 0.9V/μm, which was lower than those of carbon nanotubes and nano-diamond.

Dynamics of soluble gas exchange in the airways. III. Single-exhalation breathing maneuver

1993 ◽  
Vol 75 (6) ◽  
pp. 2439-2449 ◽  
Author(s):  
S. C. George ◽  
A. L. Babb ◽  
M. P. Hlastala
Keyword(s):  
Experimental Data ◽  
Diffusion Coefficient ◽  
Flow Rate ◽  
Molecular Diffusion ◽  
Human Subjects ◽  
Alcohol Concentration ◽  
Phase Iii ◽  
Positive Slope ◽  
Breathing Maneuver ◽  
Pulmonary Airways

The exchange characteristics of a highly soluble gas with the pulmonary airways during a single-exhalation maneuver were analyzed using a mathematical model previously described by our group (M. E. Tsu et al. Ann. Biomed. Eng. 16: 547–571, 1988). The model integrates the simultaneous exchange of water, heat, and a soluble gas with the pulmonary airways. The purpose of this paper is to provide experimental data for model validation. Exhaled ethyl alcohol concentration profiles of human subjects were measured with an Intoxilyzer 5000 and were plotted against exhaled volume measured with a wedge spirometer. Each subject performed a series of breathing maneuvers in which exhalation flow rate was the only variable. Phase III has a positive slope (0.047 +/- 0.0089 mol alcohol in air.mol alcohol in alveolus-1.l-1) that is statistically independent (P > 0.05) of flow rate. Reducing the molecular diffusion coefficient of alcohol in the nonperfused tissue layer improves the fit of the model to the experimental data. The optimal diffusion coefficient of alcohol for all subjects was 12 +/- 5.3 (SD) x 10(-7) cm2/s, which is 8% of the diffusion coefficient of alcohol in water (1.6 x 10(-5) cm2/s). We concluded that the experimental data showing a positive slope of the exhaled alcohol profile are consistent with a reduced diffusivity of alcohol in the respiratory mucosa. The reduced diffusion coefficient enhances reabsorption of alcohol by the airways on exhalation and creates a positive phase III slope.

Growth of Highly (110) Oriented Diamond Film by Microwave Plasma Chemical Vapor Deposition

2018 ◽  
Vol 281 ◽  
pp. 893-899 ◽  
Author(s):  
Yi Fan Xi ◽  
Jian Huang ◽  
Ke Tang ◽  
Xin Yu Zhou ◽  
Bing Ren ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nucleation Density ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Si Substrates ◽  
Nucleation Stage

In this study, we propose a simple and effective approach to enhance (110) orientation in diamond films grown on (100) Si substrates by microwave plasma chemical vapor deposition. It is found that the crystalline structure of diamond films strongly rely on the CH4 concentration in the nucleation stage. Under the same growth condition, when the CH4 concentration is less than 7% (7%) in the nucleation stage, the diamond films exhibit randomly oriented structure; once the value exceeds 7%, the deposited films are strongly (110) oriented. It could be verified by experiments that the formation of (110) orientation in diamond films are related to the high nucleation density and high fraction of diamond-like carbon existing in nucleation samples.

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