Dynamic Simulation of Ultra-Shallow Implantation Profiles in Single-Crystalline Silicon

1995 ◽  
Vol 389 ◽  
Author(s):  
Matthias Posselt
Keyword(s):  
Experimental Data ◽  
Damage Accumulation ◽  
Crystalline Silicon ◽  
Critical Value ◽  
Binary Collision ◽  
Single Crystalline Silicon ◽  
Depth Profiles ◽  
High Doses ◽  
Different Doses ◽  
Good Agreement

ABSTRACTThe binary collision code Crystal-TRIM is applied to simulate 15 keV BF+2 and As+ implantations into channeling and "random" directions, at different doses. The buildup of radiation damage is described by assuming statistical creation of local amorphous regions and formation of amorphous zones if the density and/or size of the local amorphous regions exceeds a critical value. Damage accumulation during ion bombardment causes enhanced dechanneling and, therefore, the alteration of the shape of range and damage profiles. The depth profiles calculated by Crystal-TRIM show a good agreement with experimental data. The thickness of the amorphous layers formed at high doses is also in accordance with measurements.

Computer Simulation of Channeling Profile Analysis of Implantation Damage

1998 ◽  
Vol 532 ◽  
Author(s):  
Matthias Posselt
Keyword(s):  
Experimental Data ◽  
Computer Simulation ◽  
Depth Profile ◽  
Profile Analysis ◽  
Binary Collision ◽  
Comparison Of Results ◽  
Implantation Damage ◽  
Good Agreement

ABSTRACTChanneling profile analysis is simulated using the dynamic binary collision code Crystal- TRIM. A good agreement between theoretical and experimental data is found for silicon targets which were predamaged by Si+ ions of different energies and analyzed by 140 keV B+ ions. For each example the depth profile of the defects relevant for the dechanneling of the analyzing ions is given. An estimate of the annealing of such defects is obtained by comparison of results for as-implanted and annealed samples.

scholarly journals Modelling of elastic properties of sintered porous materials

2013 ◽  
Vol 469 (2154) ◽  
pp. 20120689 ◽  
Author(s):  
A. V. Manoylov ◽  
F. M. Borodich ◽  
H. P. Evans
Keyword(s):  
Experimental Data ◽  
Porous Materials ◽  
Damage Accumulation ◽  
Statistical Distributions ◽  
Metal Powders ◽  
Combined Model ◽  
Loaded Material ◽  
Sintered Materials ◽  
Good Agreement ◽  
Elastic Characteristics

Models for prediction of the elastic characteristics of natural and synthetic porous materials are re-examined and new models are introduced. First, the Vavakin–Salganik (VS) model for materials with isolated spherical pores is extended in order to take into account various statistical distributions of pore sizes. It is shown that the predictions of the extended VS model are in good agreement with experimental data for porous materials with isolated pores such as foamed titanium, porous glass and sandstone. However, the model is in a considerable disagreement with the experimental data for materials sintered from metal powders. The disagreement is explained by the presence of merged and open pores whose shapes cannot be well approximated as spheres. Using the theory of geometrical probabilities, the amount of pores that are close enough to overlap is estimated, and a model is introduced where merging pores are modelled as corresponding ellipsoids. Another modification is proposed to take into account open pores. This modification is based on the classical Rabotnov–Kachanov approach to damage accumulation in the loaded material. Finally, predictions given by the above models, and their combination is compared with experiments. A good agreement is observed between the combined model and the available experimental data for a variety of sintered materials.

scholarly journals Modeling the process of grinding feed by the method of damage accumulation

2021 ◽  
Vol 284 ◽  
pp. 02021
Author(s):  
Timmo Gavrilov
Keyword(s):  
Experimental Data ◽  
Particle Size ◽  
Energy Consumption ◽  
Damage Accumulation ◽  
Optimal Number ◽  
Grinding Process ◽  
Technological Parameters ◽  
Number Of Cycles ◽  
Working Bodies ◽  
Good Agreement

The efficiency of the process of grinding meat and bone feed depends on a number of design and technological parameters of the grinder operation. One of the most significant issues and at the same time the least studied one is the influence of the number of cycles of loading meat and bone feed with the working bodies of grinders on the particle size of the finished meat and bone feed. To study this issue, the authors proposed a method for modeling the process of grinding meat and bone feed using a stochastic B-model of cumulative damage, which is based on an understanding of the process under study at the macroscopic level and experimental data. The constructed B-model made it possible to determine the optimal number of cycles of loading meat and bone feed with the working bodies of the grinders, at which the required particle size of the finished meat and bone feed is 3...5 mm, and there is no unnecessary energy consumption of the grinding process. This number is equal to 12...18 cycles. The results obtained by the B-model are in good agreement with the experimental data. The constructed B-model of the grinding process of meat and bone feed will further help optimizing the operation of the cutting device and reducing energy consumption for the operation of the grinders as a whole.

Modeling of Damage Accumulation during Ion Implantation into Single‐Crystalline Silicon

1997 ◽  
Vol 144 (4) ◽  
pp. 1495-1504 ◽  
Author(s):  
M. Posselt ◽  
B. Schmidt ◽  
C. S. Murthy ◽  
T. Feudel ◽  
K. Suzuki
Keyword(s):  
Ion Implantation ◽  
Damage Accumulation ◽  
Crystalline Silicon ◽  
Single Crystalline Silicon ◽  
Single Crystalline

Effects of Two Different Doses of Hirudin on APTT, Determined with Eight Different Reagents

1995 ◽  
Vol 73 (02) ◽  
pp. 219-222 ◽  
Author(s):  
Manuel Monreal ◽  
Luis Monreal ◽  
Rafael Ruiz de Gopegui ◽  
Yvonne Espada ◽  
Ana Maria Angles ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Anticoagulant Activity ◽  
Subcutaneous Administration ◽  
In Vitro Study ◽  
Ex Vivo Model ◽  
Suitable Candidate ◽  
Significant Prolongation ◽  
High Doses ◽  
Different Doses

SummaryThe APTT has been considered the most suitable candidate to monitor the anticoagulant activity of hirudin. However, its use is hampered by problems of standardization, which make the results heavily dependent on the responsiveness of the reagent used. Our aim was to investigate if this different responsiveness of different reagents when added in vitro is to be confirmed in an ex vivo study.Two different doses of r-hirudin (CGP 39393), 0.3 mg/kg and 1 mg/kg, were administered subcutaneously to 20 New Zealand male rabbits, and the differences in prolongation of APTT 2 and 12 h later were compared, using 8 widely used commercial reagents. All groups exhibited a significant prolongation of APTT 2 h after sc administration of hirudin, both at low and high doses. But this prolongation persisted 12 h later only when the PTTa reagent (Boehringer Mannheim) was used. In general, hirudin prolonged the APTT most with the silica- based reagents.In a further study, we compared the same APTT reagents in an in vitro study in which normal pooled plasma was mixed with increasing amount of hirudin. We failed to confirm a higher sensitivity for silica- containing reagents. Thus, we conclude that subcutaneous administration of hirudin prolongs the APTT most with the silica-based reagents, but this effect is exclusive for the ex vivo model.

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