scholarly journals Visualization and diagnostics of reliability of the object with changing the functioning conditions

2021 ◽  
Vol 263 ◽  
pp. 02009
Author(s):  
Evgeny Gvozdev
Keyword(s):  
Technological Process ◽  
Safety Margin ◽  
Operating Conditions ◽  
Hazardous Substances ◽  
Structural Elements ◽  
Base Materials ◽  
Reliability Indicator ◽  
Margin Of Safety ◽  
Fire And Explosion

The object of the scientific research is buildings (structures), which requiring the determination of a reliability indicator for their further operation in new operating conditions, the determination of additional loads in the form of (explosions, fires, vibration processes). The solution to such problems is relevant for buildings (structures), which are acquired (leased) by the owner, for their further operation in the new conditions of the technological process associated with the handling, storage, processing and production of fire and explosion hazardous substances (materials). It is important to determine the readiness of buildings (structures) for operation in the new conditions of functioning of the technological process of production, it is proposed to use deterministic, statistical and probabilistic approaches. It is proposed to use a simplified assessment of the safety margin of a building (structure) by yield strengths (for steel elements) and strength (for base materials, load-bearing walls, partitions and ceilings) corresponding to the maximum allowable values for their destruction. The innovative approach is described that allows us to solve the problems of assessing the strength reliability of structural elements of buildings (structures) to obtain guaranteed characteristics of a given margin of safety, its resistance to possible realized effects (explosions, fires, vibration processes)

PROBABILISTIC DETERMINATION OF TECHNOSPHERE OBJECT RELIABILITY UNDER HAZARDOUS INFLUENCES

2020 ◽  
Vol 15 (6) ◽  
pp. 809-818
Author(s):  
E.V. Gvozdev ◽  
Keyword(s):  
Safety Margin ◽  
Theoretical Description ◽  
Point Of View ◽  
Theory And Practice ◽  
Hazardous Substances ◽  
Building Structure ◽  
Reliability Indicators ◽  
Base Materials ◽  
Margin Of Safety

The subject of research is the process associated with determining the reliability parameter of buildings (structures) for their further operation in the technological process, causing effects in the form of additional loads (explosions, fires, vibration processes). The solution of such problems is relevant for the buildings (structures) acquired (rented) by the owner for further operation in the production process, in the technology of which fire and explosion hazardous substances (materials) are handled, stored or processed. The purpose of the study is to develop an approach that allows one to determine the parameter of the reliability of a building (structure) for operation under additional loads. To determine the indicators of safe permissible states of buildings (structures), the use of various criterion characteristics included in the content of deterministic, statistical and probabilistic approaches is given. A feature of assessing the reliability of buildings (structures) for their operation under additional loads (explosions, fires, vibration processes) is to determine the indicator of a given margin of safety and its stability under possible realized impacts. To solve the problem, it is proposed to use a simplified assessment of the safety margin of a building (structure) in terms of yield strength (for steel elements) and strength (for base materials, load-bearing walls, partitions and ceilings) corresponding to the maximum permissible values for their destruction. A consistent theoretical description of the formulas is presented, which makes it possible to establish a relationship between the safety margin of a building (structure) and the probability of its destruction under the implemented influences. An innovative approach is described that allows solving problems of assessing the strength reliability of structural elements of buildings (structures), when it is important to obtain guaranteed characteristics of an indicator of a given safety margin, its resistance to possible realized influences (explosions, fires, vibration processes). The use of the material in order to determine the reliability indicators based on risks allows us to consider the calculated values of the safety margin of a building (structure), which meets the established requirements for assessing efficiency from the point of view of the theory and practice of operations research.

scholarly journals New approach to risk assessment of certain agricultural products

2021 ◽  
pp. 44-57
Author(s):  
Oleksandr Oliynyk ◽  
Olena Skoromna ◽  
Oleksandr Gorokh ◽  
Vitaliya Mishchenko ◽  
Maryna Yevdokimova
Keyword(s):  
Risk Assessment ◽  
Methodological Approach ◽  
Safety Margin ◽  
Agricultural Products ◽  
Risk Level ◽  
Net Income ◽  
New Approach ◽  
Margin Of Safety ◽  
Break Even Point

Purpose. The main purpose of the research is to substantiate a new approach to assessing the risk of production and sales of certain types of the agricultural products. Methodology / approach. The abstract-and-logical method (systematization of publications on risk assessment of the risk level); the economic and statistical one (determination of root-mean-square deviation (δ), the coefficient of variation (v), and the coefficient of residual variation); the marginal analysis (determination of the break-even level of production of certain types of the products) have been used. Results. The methodological approach that allows determining the risk level of certain types of the products has been developed and it has been proposed to determine not only with the help of the break-even point, but also to supplement the following indicators – determining the reserve of safety and the reserve of financial strength. It is proved that similar obtained assessments of the certain product type production risk level using the analysis of variation indices can be reached by examining the break-even point indices, financial safety margin and the margin of safety. Research results show that unlike variation indices, the break-even point index, the financial safety margin index and the margin of safety index show the maximum amount of possible net income reduction. Originality / scientific novelty. The methodical approach to the assessment of the risk level of agricultural production at the given level of profitability, which is based on the comparison of the levels of production intensity of certain types of the products, that ensures their break-even point, has been substantiated. Practical value. The application of the proposed methodological approach allows the managers to determine how much to reduce the amount of the net income or the level of production intensity, but not to fall into the zone of loss.

scholarly journals DETERMINATION OF THE TECHNICAL CONDITION OF A RAILWAY BRIDGE

2020 ◽  
pp. 32-39
Author(s):  
I. Seryh ◽  
E. Chernyshova ◽  
A. Degtyar
Keyword(s):  
Technical Condition ◽  
Operating Conditions ◽  
Industrial Safety ◽  
Normal Operation ◽  
Bridge Structure ◽  
Structural Elements ◽  
Railway Bridge ◽  
Technical Examination ◽  
Second Category

The reliability and durability of any structures, including in transportation, depend on operating conditions and on timely diagnostics of damages and defects arising during their normal operation. Proper diagnostics will allow to determine the degree of wear of the structures, as well as to identify causes of damages. This work will focus on industrial safety inspection, using railway bridge built in 1987 as an example. A comprehensive inspection included full technical examination of the bridge and all its structural elements. The outcome and all necessary repair recommendations are documented. Recommendations for reconstruction and restoration methods of the damaged elements and structures of the bridge are based on a scientifically accurate assessment of its technical condition to establish signs and causes of the damages. Based on the results of the comprehensive inspection of all the damages in the bridge structure, the technical condition of the bridge is assessed three points on a five-point scale. The identified failures in durability and safety are classified in the second category. The categories of defects found are mainly related to safety - B1, B2, durability - D2, D3, and repairability - P2, Р3.

Simulation and Contrast Analysis of tem Images of Cracks

1990 ◽  
Vol 48 (1) ◽  
pp. 578-579
Author(s):  
D. Goyal ◽  
A. H. King
Keyword(s):  
Displacement Vector ◽  
Crack Tip ◽  
Perfect Crystal ◽  
Operating Conditions ◽  
Displacement Fields ◽  
Fringe Contrast ◽  
Orthogonal Geometry ◽  
Moire Fringe ◽  
Moiré Fringe

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.

scholarly journals Structural design principles for specific ultra-high affinity interactions between colicins/pyocins and immunity proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Avital Shushan ◽  
Mickey Kosloff
Keyword(s):  
Protein Interactions ◽  
Structural Elements ◽  
Protein Protein Interactions ◽  
Immunity Protein ◽  
Rational Engineering ◽  
High Affinity ◽  
Comparative Structure ◽  
Polar Interactions ◽  
Exquisite Specificity

AbstractThe interactions of the antibiotic proteins colicins/pyocins with immunity proteins is a seminal model system for studying protein–protein interactions and specificity. Yet, a precise and quantitative determination of which structural elements and residues determine their binding affinity and specificity is still lacking. Here, we used comparative structure-based energy calculations to map residues that substantially contribute to interactions across native and engineered complexes of colicins/pyocins and immunity proteins. We show that the immunity protein α1–α2 motif is a unique structurally-dissimilar element that restricts interaction specificity towards all colicins/pyocins, in both engineered and native complexes. This motif combines with a diverse and extensive array of electrostatic/polar interactions that enable the exquisite specificity that characterizes these interactions while achieving ultra-high affinity. Surprisingly, the divergence of these contributing colicin residues is reciprocal to residue conservation in immunity proteins. The structurally-dissimilar immunity protein α1–α2 motif is recognized by divergent colicins similarly, while the conserved immunity protein α3 helix interacts with diverse colicin residues. Electrostatics thus plays a key role in setting interaction specificity across all colicins and immunity proteins. Our analysis and resulting residue-level maps illuminate the molecular basis for these protein–protein interactions, with implications for drug development and rational engineering of these interfaces.

scholarly journals Stability charts based on the finite element method for underground cavities in soft carbonate rocks: validation through case-study applications

2019 ◽  
Vol 19 (10) ◽  
pp. 2079-2095 ◽  
Author(s):  
Michele Perrotti ◽  
Piernicola Lollino ◽  
Nunzio Luciano Fazio ◽  
Mario Parise
Keyword(s):  
Finite Element ◽  
Safety Margin ◽  
Structural Elements ◽  
The Finite Element Method ◽  
Geometrical Features ◽  
Overall Stability ◽  
Underground Cavities ◽  
The Stability ◽  
Rock Mechanical Properties

Abstract. The stability of man-made underground cavities in soft rocks interacting with overlying structures and infrastructures represents a challenging problem to be faced. Based upon the results of a large number of parametric two-dimensional (2-D) finite-element analyses of ideal cases of underground cavities, accounting for the variability both cave geometrical features and rock mechanical properties, specific charts have been recently proposed in the literature to assess at a preliminary stage the stability of the cavities. The purpose of the present paper is to validate the efficacy of the stability charts through the application to several case studies of underground cavities, considering both quarries collapsed in the past and quarries still stable. The stability graphs proposed by Perrotti et al. (2018) can be useful to evaluate, in a preliminary way, a safety margin for cavities that have not reached failure and to detect indications of predisposition to local or general instability phenomena. Alternatively, for sinkholes that already occurred, the graphs may be useful in identifying the conditions that led to the collapse, highlighting the importance of some structural elements (as pillars and internal walls) on the overall stability of the quarry system.

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