scholarly journals Расчет доз аморфизации кремния при облучении легкими ионами средних энергий

2020 ◽  
Vol 54 (8) ◽  
pp. 771
Author(s):  
Е.В. Окулич ◽  
В.И. Окулич ◽  
Д.И. Тетельбаум
Keyword(s):  
Experimental Data ◽  
Defect Formation ◽  
Ion Irradiation ◽  
Total Concentration ◽  
Kinetic Equations ◽  
Threshold Value ◽  
Atomic Displacement ◽  
Experimental Values ◽  
Comparison Of The Results ◽  
Ion Current Density

Based on the previously proposed diffusion–coagulation model of defect formation under ion irradiation of silicon and numerically solving the corresponding kinetic equations, amorphization doses (Фam) for ions of medium energy with a mass of M1 ≤ 31 a.m.u. were calculated. It is assumed that amorphization at a given depth occurs at a dose at which a certain threshold value of the total concentration of vacancies and divacancies (Cam) is reached. Variable parameters in the calculations were: ion energy, ion current density, temperature, as well as the threshold atomic displacement energy of atom (Ed) and Cam. Limits of the diffusion–coagulation model are determined. Comparison of the results of calculations carried out at these limits with published experimental data showed (taking into account the variation of the experimental data and a certain freedom of choice of the parameters Ed and Cam) a satisfactory agreement between the calculated and experimental values of Фam.

scholarly journals A comparative analysis of several material models in LS-DYNA at high velocity impact

2019 ◽  
Vol 221 ◽  
pp. 01007
Author(s):  
Arina Bakulina ◽  
Andrey Buzyurkin
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
High Velocity Impact ◽  
Element Analysis ◽  
Material Models ◽  
Dynamic Hardness ◽  
Velocity Impact ◽  
Analysis Package ◽  
Experimental Values ◽  
Comparison Of The Results

The questions of application of the LS-DYNA finite element analysis package for describing the interaction of a spherical projectile and a massive metal obstacle are considered. Based on a comparison of the results of numerical simulation with experimental data, a qualitative possibility has been shown to determine the magnitude of the dynamic hardness of the obstacle material.A simulation of the collision of a spherical impactor and a massive metal barrier shaped as a cube is performed. Data are obtained on the penetration of the striker into the barrier.Using the simulation curve, the values of the dynamic hardness of the obstacle were restored and a comparison was made with their experimental values. The qualitative correspondence is shown.

Xenon ion irradiation of superconducting YBa2Cu3O7 thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 92-93
Author(s):  
H. Watanabe ◽  
B. Kabius ◽  
B. Roas ◽  
K. Urban
Keyword(s):  
Defect Formation ◽  
Ion Irradiation ◽  
High Resolution Electron Microscopy ◽  
Structural Disorder ◽  
Flux Lines ◽  
Pinning Effect ◽  
Magnetic Flux Lines ◽  
Resolution Electron ◽  
Radiation Induced ◽  
Induced Defects

Recently it was reported that the critical current density(Jc) of YBa2Cu2O7, in the presence of magnetic field, is enhanced by ion irradiation. The enhancement is thought to be due to the pinning of the magnetic flux lines by radiation-induced defects or by structural disorder. The aim of the present study was to understand the fundamental mechanisms of the defect formation in association with the pinning effect in YBa2Cu3O7 by means of high-resolution electron microscopy(HRTEM).The YBa2Cu3O7 specimens were prepared by laser ablation in an insitu process. During deposition, a substrate temperature and oxygen atmosphere were kept at about 1073 K and 0.4 mbar, respectively. In this way high quality epitaxially films can be obtained with the caxis parallel to the <100 > SrTiO3 substrate normal. The specimens were irradiated at a temperature of 77 K with 173 MeV Xe ions up to a dose of 3.0 × 1016 m−2.

A CONTRIBUTION TO THE QUALITATIVE GC ANALYSIS OF SOME NON-CHLORINATED XENOBIOTIC CHEMICALS IN WASTE WATERS

1994 ◽  
Vol 30 (3) ◽  
pp. 91-93 ◽  
Author(s):  
Biljana D. Škrbic ◽  
Mirjana B. Vojinovic-Miloradov
Keyword(s):  
Experimental Data ◽  
Stationary Phases ◽  
Retention Indices ◽  
Waste Waters ◽  
Gc Analysis ◽  
Experimental Values ◽  
Xenobiotic Chemicals

Gas chromatographic unified retention indices of some chlorinated xenobiotic chemicals, as pollutants in waste waters, on OV-101 and SE-30 stationary phases are presented. These values agree well with the corresponding experimental values used in the statistical treaunent of the experimental data.

scholarly journals An Additive Model to Predict the Rheological and Mechanical Properties of Polypropylene Blends Made by Virgin and Reprocessed Components

Recycling ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Francesco Paolo La Mantia ◽  
Maria Chiara Mistretta ◽  
Vincenzo Titone
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Additive Model ◽  
Industrial Process ◽  
Theoretical Predictions ◽  
Experimental Values ◽  
Polypropylene Blends ◽  
Polypropylene Sample

In this work, an additive model for the prediction of the rheological and mechanical properties of monopolymer blends made by virgin and reprocessed components is proposed. A polypropylene sample has been reprocessed more times in an extruder and monopolymer blends have been prepared by simulating an industrial process. The scraps are exposed to regrinding and are melt reprocessed before mixing with the virgin polymer. The reprocessed polymer is, then, subjected to some thermomechanical degradation. Rheological and mechanical experimental data have been compared with the theoretical predictions. The results obtained showed that the values of this simple additive model are a very good fit for the experimental values of both rheological and mechanical properties.

Features of Defect Formation in Nanostructured Silicon under Ion Irradiation

2019 ◽  
Vol 53 (6) ◽  
pp. 800-805 ◽  
Author(s):  
A. V. Kozhemiako ◽  
A. P. Evseev ◽  
Yu. V. Balakshin ◽  
A. A. Shemukhin
Keyword(s):  
Defect Formation ◽  
Ion Irradiation ◽  
Nanostructured Silicon

scholarly journals Correction and accuracy improvement of non-parallel shear zone model

2018 ◽  
Vol 207 ◽  
pp. 02002
Author(s):  
Yaoke Wang ◽  
Meng Kou ◽  
Wei Ding ◽  
Huan Ma ◽  
Liangshan Xiong
Keyword(s):  
Experimental Data ◽  
Cutting Force ◽  
Shear Zone ◽  
Coordinate Transformation ◽  
Chip Thickness ◽  
Zone Model ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
Experimental Values ◽  
1045 Steel

When applying the non-parallel shear zone model to predict the cutting process parameters of carbon steel workpiece, it is found that there is a big error between the prediction results and the experimental values. And also, the former approach to obtain the relevant cutting parameters of the non-parallel shear zone model by applying coordinate transformation to the parallel shear zone model has a theoretical error – it erroneously regards the determinant (|J|) of the Jacobian matrix (J) in the coordinate transformation as a constant. The shape of the shear zone obtained when |J| is not constant is drew and it is found that the two boundaries of the shear zone are two slightly curved surfaces rather than two inclined planes. Also, the error between predicted values and experimental values of cutting force and cutting thrust is slightly smaller than that of constant |J|. A corrected model where |J| is a variable is proposed. Since the specific values of inclination of the shear zone (α, β), the thickness coefficient of the shear zone (as) and the constants related to the material (f0, p) are not given in the former work, a method to obtain the above-mentioned five constants by solving multivariable constrained optimization problem based on experimental data was also proposed; based on the obtained experimental data of AISI 1045 steel workpiece cutting force, cutting thrust, chip thickness, the results of five above-mentioned model constants are obtained. It is found that, compared with prediction from uncorrected model, the cutting force and cutting thrust of AISI 1045 steel predicted by the corrected model with the obtained constants has a better agreement with the experimental values obtained by Ivester.

Study on the Formula of Settling Velocity of Sediment Particle Cloud in the Water

2012 ◽  
Vol 212-213 ◽  
pp. 225-229
Author(s):  
Jie Gu ◽  
Dan Qing Ma ◽  
Wei Chen ◽  
Xin Qin ◽  
Xiao Li Wang
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Settling Velocity ◽  
Sediment Particle ◽  
Particle Cloud ◽  
Characteristic Particle ◽  
Experimental Values ◽  
New Formula ◽  
Sediment Settling

Based on the experimental data of sediment particle cloud during the settlement process in the water and combined with the existed sediment settling velocity formulae, a new formula for calculation of the settling velocity of sediment particle cloud is proposed by the introduction of the characteristic particle size of sediment particle cloud ( D' ). By using experimentally measured settling velocity values of sediment particle cloud to verify the settling velocity values of sediment particle cloud which calculated by using this new formula, the results show that the calculated settling velocity values using this new formula are closer to the experimental values.

Application of Polyhedral Mesh for Vortex Formation Study for Simple Single Pump Sump

CFD letters ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 13-27
Author(s):  
Mohamad Lutfi Samsudin ◽  
Hasril Hasini
Keyword(s):  
Experimental Data ◽  
Complex Geometry ◽  
Vortex Formation ◽  
Tetrahedral Mesh ◽  
Published Data ◽  
Hexahedral Mesh ◽  
The Past ◽  
Polyhedral Mesh ◽  
Pump Sump ◽  
Comparison Of The Results

Meshing of domain in CFD is an important step to ensure accuracy of the solution. In the past, hexahedral or tetrahedral mesh systems were commonly used, and both have their merits and demerits. For large and complex geometry, polyhedral is another option but its accuracy is claimed to be lacking. In this paper, the use of polyhedral mesh system by past researchers are reviewed. Evaluation on the application of polyhedral mesh system for the study of the vortex formation with a simple single pump sump model is made. Validation was made through the comparison of the results from hexahedral, tetrahedral and polyhedral mesh sizes and the experimental data from published data. The polyhedral mesh system was found to perform satisfactorily and was able to match the results from the hexahedral mesh system as well as the experimental data.

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