Comparison of the results of analytical and numerical model calculations of electron backscattering from supported films

2002 ◽  
Vol 18 (3) ◽  
pp. 155-162 ◽  
Author(s):  
M. Dapor
Keyword(s):  
Numerical Model ◽  
Model Calculations ◽  
Electron Backscattering ◽  
Comparison Of The Results

scholarly journals Solar Extreme and Far Ultraviolet Radiation Modeling for Aeronomic Calculations

2021 ◽  
Vol 13 (8) ◽  
pp. 1454
Author(s):  
Anatoliy A. Nusinov ◽  
Tamara V. Kazachevskaya ◽  
Valeriya V. Katyushina
Keyword(s):  
Ultraviolet Radiation ◽  
Input Parameter ◽  
Solar Spectrum ◽  
Upper Atmosphere ◽  
Model Calculations ◽  
Radiation Fluxes ◽  
Main Components ◽  
Comparison Of The Results ◽  
Far Ultraviolet ◽  
Radiation Modeling

Modeling the upper atmosphere and ionospheres on the basis of a mathematical description of physical processes requires knowledge of ultraviolet radiation fluxes from the Sun as an integral part of the model. Aeronomic models of variations in the radiation flux in the region of extreme (EUV) and far (FUV) radiation, based mainly on the data of the last TIMED mission measurements of the solar spectrum, are proposed. The EUVT model describes variations in the 5–105 nm spectral region, which are responsible for the ionization of the main components of the earth’s atmosphere. The FUVT model describes the flux changes in the 115–242 nm region, which determines heating of the upper atmosphere and the dissociation of molecular oxygen. Both models use the intensity of the hydrogen Lyman-alpha line as an input parameter, which can currently be considered as one of the main indices of solar activity and can be measured with relatively simpler photometers. A comparison of the results of model calculations with observations shows that the model error does not exceed 1–2% for the FUVT model, and 5.5% for EUVT, which is sufficient for calculating the parameters of the ionosphere and thermosphere.

Electrolyte diodes with weak acids and bases. II. Numerical model calculations and experiments

2005 ◽  
Vol 123 (16) ◽  
pp. 164510 ◽  
Author(s):  
Kristóf Iván ◽  
Mária Wittmann ◽  
Péter L. Simon ◽  
Zoltán Noszticzius ◽  
Dalimil Šnita
Keyword(s):  
Numerical Model ◽  
Weak Acids ◽  
Model Calculations ◽  
Acids And Bases

Constraints on the formation of submarine lava flows from numerical model calculations

1999 ◽  
Vol 92 (3-4) ◽  
pp. 215-229 ◽  
Author(s):  
F. Klingelhöfer ◽  
M. Hort ◽  
H.-J. Kümpel ◽  
H.-U. Schmincke
Keyword(s):  
Numerical Model ◽  
Lava Flows ◽  
Model Calculations ◽  
Submarine Lava

Study of Gas Recycling in the GAMMA 10 Tandem Mirror Based on Numerical Model Calculations

1995 ◽  
Vol 34 (Part 1, No. 7A) ◽  
pp. 3689-3696 ◽  
Author(s):  
Katsuhiko Tsuchiya ◽  
Yousuke Nakashima ◽  
Kiyoshi Yatsu ◽  
Mamoru Shoji ◽  
Makoto Ichimura ◽  
...  
Keyword(s):  
Numerical Model ◽  
Model Calculations ◽  
Tandem Mirror ◽  
Gas Recycling

scholarly journals INCREASING STRUCTURE STIFFNESSOF CORRUGATED ALUMINUM SPOOL

2021 ◽  
Vol 23 (4) ◽  
pp. 12-17
Author(s):  
V.Y. Aryshenskii ◽  
◽  
F.V. Grechnikov ◽  
S.V. Glushkov ◽  
◽  
...  
Keyword(s):  
Testing Machine ◽  
Vertical Wall ◽  
Weight Ratio ◽  
Metal Consumption ◽  
Empirical Formulas ◽  
Critical Height ◽  
Model Calculations ◽  
Strength Performance ◽  
Normative Documents ◽  
Comparison Of The Results

The paper presents the results of a computational and experimental study of aluminumspools with different profile configurations. Mathematical modeling of the product was made using ANSYS 18.2 software package. Models were verified based on actual test results on FP-100/1-10tn testing machine in JSC “Arconic SMZ” Central Factory Lab as per valid normative documents. The study was made on a trial lot of spools with a specially developed type of profile. Comparative analysis was carried out against purchased spools with a profile previously developed by the spool supplier.The spools under study were made of alloy 3104 H19, 0.26 mm strip thickness. The study resulted in work out of empirical formulas helping to determinecollapse loadand calculate the amount of metal forevaluationof stiffness-to-weight ratio. The proposed formulas were added with dimensionlesscoefficients to account for the profile configuration (shape factor) and the relative height of the profile wall.The coefficients were presented in the form of nomograms for easygraphical assessment of the profile performance.The critical height of the profile was determined, at which specific stiffness of the structure is the highest.It was demonstrated that a profile with an inclined vertical wall and a profile with an omega-shaped inner generatrix have lower stiffness than a profile with vertical U-shaped corrugations.The optimal range of the corrugation wall tilt angle was determined to ensure the required level of the structure stiffness, on the one hand, and minimize metal consumption, on the other hand. Comparison of the results of model calculations, the results of computation by the proposed empirical dependencies and actual experimental data showed their high repeatability, whichleads to the conclusion that the proposed formulas are applicable for engineering calculations.The developed profile of a special type makes it possible to reduce the spool metal consumption by 13% while maintaining the required strength performance and the level of stiffness.

The Role of Latent Heating Anomalies in Exciting the Summertime Eurasian Circulation Trend Pattern and High Surface Temperature

2021 ◽  
pp. 1-43
Author(s):  
Dong Wan Kim ◽  
Sukyoung Lee
Keyword(s):  
Numerical Model ◽  
Surface Temperature ◽  
High Surface ◽  
Boreal Summer ◽  
Latent Heating ◽  
The Caspian Sea ◽  
Model Calculations ◽  
Trend Pattern ◽  
Warm Anomaly ◽  
Upper Level

AbstractDynamical mechanisms for the summer Eurasian circulation trend pattern are investigated by analyzing reanalysis data and conducting numerical model simulations. The daily circulations that resemble the Eurasian circulation trend pattern are identified and categorized into two groups based on surface warming signal over central and eastern Europe. In the group with large warm anomaly, the upper-level circulation takes on a wave packet form over Eurasia, and there are enhanced latent heating anomalies centered over the North Sea and suppressed latent heating anomalies over the Caspian Sea. The numerical model calculations indicate that these latent heating anomalies can excite an upper-level circulation response that resembles the Eurasian circulation trend pattern. Additional analysis indicates that trends of these two latent heating centers contribute to the long-term circulation trend. In the weak warm anomaly group, the circulation pattern takes on a circumglobal teleconnection (CGT) pattern, and there is no heating signal that reinforces the circulation. These results indicate that not all CGT-like patterns excite temperature anomalies which are persistent and in phase with the trend pattern, and that quasi-stationary forcings, such as the latent heating anomalies, play an important role in driving the boreal summer circulation anomaly that accompanies the strong and persistent surface temperature signal.

scholarly journals Downfront Winds over Buoyant Coastal Plumes

2016 ◽  
Vol 46 (10) ◽  
pp. 3139-3154 ◽  
Author(s):  
Michael A. Spall ◽  
Leif N. Thomas
Keyword(s):  
Numerical Model ◽  
Potential Vorticity ◽  
Baroclinic Instability ◽  
Vertical Mixing ◽  
Stable Stratification ◽  
Relative Vorticity ◽  
Mixing Rate ◽  
Diapycnal Mixing ◽  
Model Calculations ◽  
Horizontal Density Gradient

AbstractDownfront, or downwelling favorable, winds are commonly found over buoyant coastal plumes. It is known that these winds can result in mixing of the plume with the ambient water and that the winds influence the transport, spatial extent, and stability of the plumes. In the present study, the interaction of the Ekman velocity in the surface layer and baroclinic instability supported by the strong horizontal density gradient of the plume is explored with the objective of understanding the potential vorticity and buoyancy budgets. The approach makes use of an idealized numerical model and scaling theory. It is shown that when winds are present the weak stratification resulting from vertical mixing and the strong baroclinicity of the front results in near-zero average potential vorticity q. For weak to moderate winds, the reduction of q by diapycnal mixing is balanced by the generation of q through the geostrophic stress term in the regions of strong horizontal density gradients and stable stratification. However, for very strong winds the wind stress overwhelms the geostrophic stress and leads to a reduction in q, which is balanced by the vertical mixing term. In the absence of winds, the geostrophic stress dominates mixing and the flow rapidly restratifies. Nonlinearity, extremes of relative vorticity and vertical velocity, and mixing are all enhanced by the presence of a coast. Scaling estimates developed for the eddy buoyancy flux, the surface potential vorticity flux, and the diapycnal mixing rate compare well with results diagnosed from a series of numerical model calculations.

Model calculations of isotope effects. VIII. Deprotonation of nitroethane

1983 ◽  
Vol 36 (8) ◽  
pp. 1513
Author(s):  
DJ McLennan
Keyword(s):  
Transition State ◽  
Isotope Effects ◽  
Deuterium Isotope Effect ◽  
Model Calculations ◽  
Kinetic Isotope ◽  
Partial Negative Charge ◽  
Hydrogen Deuterium ◽  
State Models ◽  
Experimental Values ◽  
Comparison Of The Results

Transition-state models for the base-promoted deprotonation of nitroethane have been designed, and primary and secondary hydrogen-deuterium kinetic isotope effects have been calculated. Comparison of the results with experimental values of the primary isotope effects allows no firm conclusions to be reached concerning probable transition-state structures. However, the secondary α-deuterium isotope effect comparison disqualifies from consideration those transition states in which rehybridization of Cα and delocalization of the partial negative charge by the nitro group keep pace with the extent of deprotonation. Transition-state models wherein Cα is carbanionic and essentially pyramidal yield theoretical isotope effects lying within the experimental range.

Sign in / Sign up

Export Citation Format

Share Document