The study of regularities of changes in acoustic characteristics depending on microstructure parameters and development of acoustic limit state criterion

2020 ◽  
pp. 32-42
Author(s):  
V. N. Gadalov ◽  
S. V. Safonov ◽  
E. A. Filatov ◽  
O. N. Boldyreva ◽  
I. A. Makarova
Keyword(s):  
Structural Damage ◽  
Limit State ◽  
Acoustic Characteristics ◽  
Term Operation ◽  
Long Run ◽  
Microstructure Parameters ◽  
State Criterion ◽  
Good Agreement

The studies of the dependence of acoustic characteristics on the microstructure of chromium-molybdenum-vanadium steels in various structural states after long term operation are presented. The meaning of the acoustic limit state criterion, which represents a relative assessment of accumulated structural damage of the long run metal for the time delay of ultrasonic Rayleigh waves and determination of the limit state of the material, is revealed. It is established that at the acoustic criterion of the limit state of ≥0.7, the metal is in the state of avalanche creep and reaches the limit state. Measurements of acoustic characteristics gave a good agreement with the results of metallographic studies conducted on sections of metal cuttings. In addition, the criterion was tested when diagnosing technical devices made of steel 15X1M1F, 12X2MFSR, 17GS, 09G2S.

scholarly journals Application of the classical Payout Ratio Model and determination of the limitations of the Lintner Model demonstrated on the example of Komerční banka, PLC

2021 ◽  
Vol 91 ◽  
pp. 01043
Author(s):  
Veronika Machova ◽  
Tereza Geierova
Keyword(s):  
Annual Reports ◽  
Ratio Model ◽  
Company Strategy ◽  
Term Operation ◽  
Long Run

Initial determination of the payout ratio should be an integral part of each company strategy; it is a cornerstone of a long-term operation of any company. The aim of this contribution is to analyse the possibilities of determining the payout ratio of the company using dividend models and to design the most optimal application of the dividend model, and to define the limitations for the application. The data required for the application of the dividend models are obtained from the annual reports of Komerční banka, PLC. for the years of 2006-2018. The obtained data are used to calculate the classical payout ratio model, and subsequently to determine the payout ratio according to the Lintner model. Using the method of comparison, the obtained results for the application of the pay ratio are contrasted. The classic payout ratio model coincided directly with the results of the payout ratios of Komerční banka, PLC. and therefore turned out to be optimal for the application. The Lintner model is considered in literature to be very well functioning. However, this research confirmed that the resulting values of payout ratios after the application of the Lintner model are unacceptable in the long run.

scholarly journals Steady-State Analysis of Genetic Regulatory Networks Modelled by Probabilistic Boolean Networks

2003 ◽  
Vol 4 (6) ◽  
pp. 601-608 ◽  
Author(s):  
Ilya Shmulevich ◽  
Ilya Gluhovsky ◽  
Ronaldo F. Hashimoto ◽  
Edward R. Dougherty ◽  
Wei Zhang
Keyword(s):  
Markov Chain ◽  
Steady State ◽  
Markov Chains ◽  
Regulatory Networks ◽  
Boolean Networks ◽  
Genetic Regulatory Networks ◽  
Long Run ◽  
Probabilistic Boolean Networks

Probabilistic Boolean networks (PBNs) have recently been introduced as a promising class of models of genetic regulatory networks. The dynamic behaviour of PBNs can be analysed in the context of Markov chains. A key goal is the determination of the steady-state (long-run) behaviour of a PBN by analysing the corresponding Markov chain. This allows one to compute the long-term influence of a gene on another gene or determine the long-term joint probabilistic behaviour of a few selected genes. Because matrix-based methods quickly become prohibitive for large sizes of networks, we propose the use of Monte Carlo methods. However, the rate of convergence to the stationary distribution becomes a central issue. We discuss several approaches for determining the number of iterations necessary to achieve convergence of the Markov chain corresponding to a PBN. Using a recently introduced method based on the theory of two-state Markov chains, we illustrate the approach on a sub-network designed from human glioma gene expression data and determine the joint steadystate probabilities for several groups of genes.

Determination of Actual Tensile and Fracture Characteristics of Critical Components of Industrial Plants Under Long Term Operation by SPT

2012 ◽  
Author(s):  
Karel Matocha
Keyword(s):  
Mechanical Properties ◽  
Residual Lifetime ◽  
Test Technique ◽  
Fracture Characteristics ◽  
Industrial Plants ◽  
Term Operation ◽  
Critical Components ◽  
Time Of Operation

The assessment of the residual lifetime of critical components of industrial plants requires the knowledge of mechanical properties prior to operation, respecting all technological operations realized throughout the manufacture of the component, and the knowledge of mechanical properties after actual time of operation (actual mechanical properties). Small Punch (SP) test technique enables measurement of the realistic material properties at the critical locations in the component both prior and after long-term operation. The paper shows the examples of the sampling of testing material from the critical components of the industrial plants and the procedures for determination of tensile and fracture characteristics by SP tests at ambient and low temperatures. The special attention is devoted to the test specimen orientation for determination of SP fracture energy ESP.

Determination of Tensile Properties of Power Plant Steels by Testing of Miniature Specimens

2013 ◽  
Author(s):  
Ivan Klevtsov ◽  
Andrei Dedov
Keyword(s):  
Mechanical Properties ◽  
Power Plant ◽  
Flat Plate ◽  
Tensile Properties ◽  
Standard Size ◽  
Term Operation ◽  
University Of Technology ◽  
Miniature Specimens

Long-term operation of the power plant components in the conditions of the creep leads to the degradation of the short-term mechanical properties of the material. Therefore, in order to predict the degree of the metal degradation and integrity of the component the determination of the mechanical properties of the actual component in service material is required. Since the standard tests requiring a significant volume of sample material cannot be applied the technique of the tensile testing of miniature flat plate specimens has been developed in Tallinn University of Technology and described in this paper. The results of the tests of miniature flat plate specimens have been compared with testing results of cylindrical specimens with standard size and at the same time the comparison has shown a good agreement of the results. The data analysis has also shown the high repeatability of the tests results of miniature specimens. Thus, the developed technique of the miniature flat plate specimens testing could be considered as accurate and reliable method and could be definitely used for evaluation of the tensile properties of the metal.

Research Advances in the Interaction among Stratum-Ground Fissure-Tunnel under Subway Dynamic Loading

2012 ◽  
Vol 226-228 ◽  
pp. 1513-1516 ◽  
Author(s):  
Li Qun Yuan ◽  
Hong Jia Liu ◽  
Yu Ming Men
Keyword(s):  
Dynamic Loading ◽  
Dynamic Interaction ◽  
Subway Tunnel ◽  
Ground Fissure ◽  
Ground Fissures ◽  
Term Operation ◽  
Geological Disaster ◽  
Under Construction

Ground fissure is a kind of serious geological disaster. There will be more unprecedented challenges during the construction of the urban subway in ground fissures-developed zone. How to ensure the long-term operation safety of the subway crossing ground fissure belts are the first problems for the subway under construction in the cities with ground fissure developed. One of the important problems is that dynamic interaction and disaster effect control among ground fissure-stratum-subway tunnel under subway dynamic loading, which is also the important problem to be solved in the engineering. This problem involves the following three aspects: (a) the determination of subway dynamic loading; (b) the structure dynamic response of subway tunnel; (c) the interaction among stratum-ground fissure-subway tunnel. According to make a comment on these researches, some issues which are necessary to carry out in this field are suggested.

Development of Structural Damage and Cracking in a Landing Head during Long-Term Operation under North Conditions

2019 ◽  
Vol 2019 (10) ◽  
pp. 1074-1084
Author(s):  
V. M. Goritskii ◽  
E. L. Muravin ◽  
G. R. Shneiderov
Keyword(s):  
Structural Damage ◽  
Term Operation

scholarly journals Corrections to the Hipparcos proper motions in declination for 807 stars

2008 ◽  
pp. 109-113 ◽  
Author(s):  
G. Damljanovic ◽  
N. Pejovic
Keyword(s):  
Accurate Determination ◽  
Annual Number ◽  
Time Interval ◽  
Proper Motions ◽  
Hipparcos Catalogue ◽  
Time Variations ◽  
Better Than ◽  
Good Agreement

We used the data on latitude variations obtained from observations with 10 classical photographic zenith tubes (PZT) in order to improve the Hipparcos proper motions in declinations ?? for 807 stars. Part of observing programmes, carried out during the last century for the purpose of studying the Earth's rotation, were realized by using PZT instruments. These observations were performed within in the intervals (tens of years) much longer than that of the Hipparcos mission (less than 4 years). In addition, the annual number of observations for every PZT programme star is several hundreds on the average. Though the accuracy of the star coordinates in the Hipparcos Catalogue is by two orders of magnitude better than that of the star coordinates from the PZT observations, the large number of observations performed a much longer time interval makes it possible to correct the Hipparcos proper motions and to improve their accuracy with respect to the accuracy given in the Hipparcos Catalogue. Long term examinations of latitude and time variations were used to form the Earth Orientation Catalogue (EOC-2), aimed at a more accurate determination of positions and proper motions for the stars included. Our method of calculating the corrections of the proper motions in declination from the latitude variations is different from the method used in obtaining the EOC-2 Catalogue. Comparing the results we have established a good agreement between our ?? and the EOC-2 ones for the star sample used in the present paper.

scholarly journals Сalculation methodology and determination of efforts in vault

2021 ◽  
Vol 2 (92) ◽  
pp. 85
Author(s):  
Olena Yaremenko
Keyword(s):  
Spatial Structure ◽  
Abstract Problem ◽  
Term Operation ◽  
Unit Width ◽  
Methods Of Calculation ◽  
Central Forces ◽  
Circular Curve

Abstract. Problem. In this article we offer the meth-odology of calculation, based on the idea of dismem-berment of vault on the separate archs of single width. It is recommended for the estimation of efforts in the designed and damaged vaults. Also offered a methods of calculation effort in serried vaults. As spatial inflexibility of cross vault below than inflexi-bility of serried vault, then it is necessary to execute the calculation of the cheek arch abstracted from the tray of cross vault also. If the outline of tray is exe-cuted on a circular curve, then it is possible to take methodology of calculation of archs with the outline of axis a curve as catenoid. Goal. The proposed methodology for calculating closed and cross vaults is also based on the idea of dividing the arch into separate arches of unit width. The results of studies of efforts and rational forms of arches of V.A. Kiselev [1]. Methodology. Calculation based on the idea of dismemberment of vault on the separate archs of single width. Recommended for the estimation of efforts in the designed and damaged vaults. A method over of calculation of dome is brought for determina-tion of effort in serried vaults. Results. At the choice of outline of axis of arch it is necessary aspires to that an axis, on possibility, coincided with the curve of pressure. Such outline of axis is rational, as there are only central forces of N in an arch. Flexion mo-ments M and transversal forces of Q are equal to the zero. The coincidence of axis of arch with the curve of pressure can be got for the three-hinged arch. For the statically undetermined arch of complete coinci-dence of axis with the curve of pressure attaining is impossible, so that the origin of flexion moments at any her outline is inevitable. Originality. The tech-nique based on the separation of flat elements from the spatial structure does not show the reserves of strength of the structure. Experience of long-term operation of vaulted structures designed or verified by calculation using similar methods [2], [9] shows caution and reliability. Practical value. The tech-nique is also suitable for assessing the strength of damaged vaults with collapsed corners or walms.

Determination of Environmental Conditions Relevant for the Ultimate Limit State at an Exposed Aquaculture Location

2017 ◽  
Author(s):  
Pål Takle Bore ◽  
Jørgen Amdahl
Keyword(s):  
Environmental Conditions ◽  
Limit State ◽  
Ultimate Limit State ◽  
Distribution Method ◽  
Wave Data ◽  
Wave Conditions ◽  
One Year ◽  
Ultimate Limit

Methods for determination of environmental conditions relevant for the ultimate limit state at an exposed aquaculture location are proposed. The considered location is in Frohavet, northwest of Trondheim, Norway. Wind, waves and current are considered, but as more severe wave conditions are expected to be the most influential environmental factor when going from sheltered to more exposed locations, particular focus has been given on the description of wave conditions. The estimated long term description of wind and waves are based on 16 year of SWAN hindcast data, where the wave data have been calibrated against one year of in-situ measurements. One month of current measurements were available. The initial distribution method is used to determine the long term distribution of wind and wave conditions. The data fit the applied distributions well, but the sea state characteristics are seen to be highly directional dependent, which is important to take into account. The effect of using only one year of wave data is also investigated, showing that this can lead to significant underestimation of the extreme values. Concepts from the environmental contour line method are applied for determination of sea states corresponding to a given annual probability of exceedance. A deterministic approach from NS 9415 is used to determine the extreme current velocities. Comments on the use of directional criteria for design are also given.

Determination of VVER-440/ V-213 long-term operation induced activity

2021 ◽  
Author(s):  
Michal Šnírer ◽  
Kristína Krištofová ◽  
Gabriel Farkas ◽  
Peter Hausner ◽  
Vladimír Slugeň
Keyword(s):  
Term Operation
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