scholarly journals RESEARCH OF SELF-FORMATION NANOSTRUCTURES / NANODARINIŲ FORMAVIMOSI PROCESŲ TYRIMAS

2011 ◽  
Vol 3 (1) ◽  
pp. 59-62
Author(s):  
Romas Petrauskas
Keyword(s):  
Systematic Error ◽  
Analytical Calculation ◽  
Self Formation ◽  
Etching Duration ◽  
Calculation Models

Lateral etching processes for the modeling of the geometry of self-formation nanostructures with Silvaco TCAD Athena program are analyzed. Self-formation nanostructures is modeled with different mask selectivity values equal to 2, 10, 40 and 100 with respect to the etching layer, with the etching duration of 0–180 s. The etching rates are constant – 1.33 nm/s. The analysis of the dependence of the etching systematic error on its thickness has been carried out. The computer modeled results are close to the ones produced by means of the application of the analytical calculation models by other authors.

scholarly journals Analysis of the different techniques for calculation of bearing capacity of flexural reinforced concrete deep beams

2019 ◽  
Author(s):  
Beata Levon ◽  
Remigijus Šalna ◽  
Linas Juknevičius
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Systematic Error ◽  
Bearing Capacity ◽  
Experimental Verification ◽  
The Other ◽  
Design Codes ◽  
Shear Reinforcement ◽  
Deep Beams ◽  
Calculation Models

The paper deals with the singularities of the design of deep beams without shear reinforcement according to different design codes, namely, STR 2.05.05:2005, EC2, EC2-SMM and ACI-318. The comparative analysis of calculation models, experimental verification, accuracy of models and the ranking of models according to the Modified Demerit Points Classification (MDP) method are presented. The results shown that despite the systematic error of the STR 2.05.05:2005 method is closest to 1 if compared to the other methods, it is classified as dangerous one according to the MDP ranking.

Monte Carlo Modelling of Secondary Electron Yield from Rough Surfaces

1990 ◽  
Vol 48 (1) ◽  
pp. 422-423
Author(s):  
John C. Russ
Keyword(s):  
Monte Carlo ◽  
Energy Loss ◽  
Secondary Electron ◽  
Secondary Electron Emission ◽  
Analytical Calculation ◽  
Mean Free Path ◽  
Single Scattering ◽  
High Energy ◽  
Secondary Electron Yield ◽  
Electron Yield

Monte-Carlo programs are well recognized for their ability to model electron beam interactions with samples, and to incorporate boundary conditions such as compositional or surface variations which are difficult to handle analytically. This success has been especially powerful for modelling X-ray emission and the backscattering of high energy electrons. Secondary electron emission has proven to be somewhat more difficult, since the diffusion of the generated secondaries to the surface is strongly geometry dependent, and requires analytical calculations as well as material parameters. Modelling of secondary electron yield within a Monte-Carlo framework has been done using multiple scattering programs, but is not readily adapted to the moderately complex geometries associated with samples such as microelectronic devices, etc.This paper reports results using a different approach in which simplifying assumptions are made to permit direct and easy estimation of the secondary electron signal from samples of arbitrary complexity. The single-scattering program which performs the basic Monte-Carlo simulation (and is also used for backscattered electron and EBIC simulation) allows multiple regions to be defined within the sample, each with boundaries formed by a polygon of any number of sides. Each region may be given any elemental composition in atomic percent. In addition to the regions comprising the primary structure of the sample, a series of thin regions are defined along the surface(s) in which the total energy loss of the primary electrons is summed. This energy loss is assumed to be proportional to the generated secondary electron signal which would be emitted from the sample. The only adjustable variable is the thickness of the region, which plays the same role as the mean free path of the secondary electrons in an analytical calculation. This is treated as an empirical factor, similar in many respects to the λ and ε parameters in the Joy model.

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

Systematic error of LSM-estimation of covariance components of biperiodically correlated random signals

2019 ◽  
Vol 2019 (47) ◽  
pp. 26-33
Author(s):  
I. M. Javorskyj ◽  
◽  
O. Y. Dzeryn ◽  
R. M. Yuzefovych ◽  
◽  
...  
Keyword(s):  
Systematic Error ◽  
Covariance Components ◽  
Random Signals

Lifetime Regime in the Electrically-Detected Transient Grating Method Applied to Amorphous and Microcrystalline Silicon Films

2002 ◽  
Vol 715 ◽  
Author(s):  
P. Sanguino ◽  
M. Niehus ◽  
S. Koynov ◽  
P. Brogueira ◽  
R. Schwarz ◽  
...  
Keyword(s):  
Carrier Transport ◽  
Analytical Calculation ◽  
Chemical Vapor ◽  
Silicon Films ◽  
Dielectric Relaxation Time ◽  
Transient Grating ◽  
Minority Carrier Diffusion Length ◽  
Carrier Recombination ◽  
Thin Silicon ◽  
Good Agreement

AbstractThe minority-carrier diffusion length in thin silicon films can be extracted from the electrically-detected transient grating method, EDTG, by a simple ambipolar analysis only in the case of lifetime dominated carrier transport. If the dielectric relaxation time, τdiel, is larger than the photocarrier response time, τR, then unexpected negative transient signals can appear in the EDTG result. Thin silicon films deposited by hot-wire chemical vapor deposition (HWCVD) near the amorphous-to-microcrystalline transition, where τR varies over a large range, appeared to be ideal candidates to study the interplay between carrier recombination and dielectric response. By modifying the ambipolar description to allow for a time-dependent carrier grating build-up and decay we can obtain a good agreement between analytical calculation and experimental results.

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