scholarly journals Assessment of the residual resource of several buildings and structures as a unified object

2021 ◽  
Vol 18 (5) ◽  
pp. 49-56
Author(s):  
D. I. Korolkov ◽  
◽  
Sh. M. Mamedov ◽  
Keyword(s):  
Residual Life ◽  
Probabilistic Method ◽  
Combinatorial Method ◽  
Advantages And Disadvantages

In this article, the authors raises the problem of assessing the residual resource of an object consisting of several buildings and structures. Four different approaches to solving this problem are presented. The advantages and disadvantages of them are considered, and the application areas of these approaches are indicated. Within the framework of these approaches, one can use the direct enumeration method, the combinatorial method, the algebra of logic, and the general logical-probabilistic method. The authors has developed two possible options for calculating the residual resource of these objects using the general logical-probabilistic method. It is proposed to develop a methodology for calculating the residual life of such objects before conducting a survey. The authors indicates the main points that must be included in the developed methodology.

scholarly journals The Forecasting Residual Life of Corroding Pipeline based on Semi-Probabilistic Method

2010 ◽  
Vol 1 (2) ◽  
pp. 1-6 ◽  
Author(s):  
Noor N.M. ◽  
Yahaya N. ◽  
Ozman N.A.N ◽  
Othman S.R.
Keyword(s):  
Standard Deviation ◽  
Residual Life ◽  
Probabilistic Method ◽  
Time To Failure ◽  
Operating Pressure ◽  
Safety Factors ◽  
Internal Corrosion ◽  
Maintenance Schedule ◽  
Operating Strategies ◽  
Pipeline Failures

In general, the prediction of pipeline residual life can effectively assist pipeline operators to evaluate future safe operating strategies including re-inspection and appropriate maintenance schedule. As a result it can minimize the possibility of pipeline failures until it reaches its designed lifetime. A semi-probabilistic methodology for predicting the remaining strength of submarine pipelines subjected to internal corrosion based on Recommended Practice RP-F101 by Det Norske Veritas (DNV) is described in this paper. It is used to estimate the maximum allowable operating pressure of the corroding pipelines based on series of pigging data, which represents corrosion pit location and dimension. The introduction of partial safety factors in the DNV code to minimise the effect of uncertainties due to the defect sizing has improved the reliability of pipeline assessment methodology. Nevertheless, the code is still regarded as a fully deterministic approach due to its incapability of predicting the remaining life of corroded pipeline. Thus, we have added prediction capabilities to the capacity equation by introducing a standard deviation model of future defect depth. By doing so, the variation of safety factors of the capacity equation can be fully manipulated in which prediction of future pipeline residual life becomes feasible. The paper demonstrates calculation and prediction of pipeline residual life subjects to internal corrosion. The results shows the standard deviation of corrosion parameter affected the value of partial safety factor as corrosion progressing, hence amplify the conservatism of time to failure.

scholarly journals COVERED KARST LANDFORMS: COMPLEXIFICATION OF METHODS TO ESTIMATION OF MORPHOMETRIC PARAMETERS IN ENGINEERING PURPOSES

2018 ◽  
Vol 13 (6) ◽  
pp. 10-23 ◽  
Author(s):  
S. V. Shcherbakov ◽  
V. N. Kataev ◽  
D. R. Zolotarev ◽  
T. G. Kovaleva
Keyword(s):  
Probabilistic Method ◽  
Ground Surface ◽  
Optimal Solution ◽  
Geological Structure ◽  
Karst Area ◽  
Collapse Mechanism ◽  
Karst Collapse ◽  
Natural Environments ◽  
Karst Cavity ◽  
Advantages And Disadvantages

The research is aimed to search of optimal solution in integration of various methods for predicting the sizes of karst-suffosion deformations on the ground surface or at the base of shallow foundations. Necessity of integration is dictated by engineering-geological conditionsof the karst areas and the complexity of their reliable study with using modern approaches (drilling, geophysics etc.). From this point of view increasing of authenticity of the final forecast is in direct dependency from completeness of investigation of sizes of observed surface karstforms and features of behavior soils massif above the karst cavity. The mechanism of the karst process in the soils thickness is defined, first of all, by geological structure (thickness and interleaving of different soil layers), hydrogeological conditions and the physical-mechanicalproperties of soils. At the present day are known three basic mechanisms of soil deformation over karst cavity: karst-collapse, karst-suffosion and karst-suffosion-collapse mechanism. Even in the conditions of one site these mechanisms can be interleave during the year, which makesthe karst formation process hard-to-predict in part of diameters of sinkholes and subsidence zones. Today are known and applicable next four methods to estimations of possible sizes of karst-suffosion deformations: 1) method of analogy, 2) probabilistic method, 3) deterministic(calculated) method, 4) laboratory physical modeling method. Each of four methods for predicting the sizes of karst-suffosion deformations has its own advantages and disadvantages, which limit the possibility of using any one of them in different natural environments of karstdevelopment. To improve objectivity and reach necessity accuracy of estimation of diameters and depths of surface karst deformations in engineering-geological purposes a block-scheme of integrations of different forecasting methods is recommended. This scheme is based on the data about surface karst area, the depth of occurrence of karst rocks and level of responsibility of the projecting object.

scholarly journals Air purification from process emissions from electroplating baths

2021 ◽  
Vol 274 ◽  
pp. 08011
Author(s):  
Anna Lifanteva ◽  
Alsu Yusupova ◽  
Galina Medvedeva
Keyword(s):  
Technological Process ◽  
Probabilistic Method ◽  
Air Purification ◽  
Cleaning Process ◽  
Advantages And Disadvantages ◽  
Exhaust Ventilation ◽  
Purification Efficiency ◽  
Purification System ◽  
Air Discharge ◽  
Production Facilities

Electroplating technology is an important technological process at production facilities of various profiles. The electroplating baths are a source of hazardous emissions of toxic vapors and aerosols. In factories with electroplating sites, the crucial task is to eliminate hazardous emissions by applying an effective exhaust ventilation and air purification system for subsequent air discharge into the atmosphere. In this article two basic schemes for cleaning process emissions from electroplating baths were developed: a scheme with purification in scrubbers; a scheme with purification in scrubbers with pre-filtration. The advantages and disadvantages of each scheme were considered. Based on the amount of hazardous emissions and their dispersed composition, the purification efficiency of each scheme was calculated using the probabilistic method. In view of the calculations, a scheme for cleaning process emissions from the electroplating line with the highest purification efficiency has been identified.

scholarly journals DEVELOPING ESTIMATION ALGORITHM OF RELIABILITY INDICATORS OF INDUSTRIAL BUILDINGS

2018 ◽  
pp. 49-56
Author(s):  
Valeriy Ivanovich Trofimov ◽  
Pavel Nicolaevich Sadchikov ◽  
Sergey Valerevich Belov
Keyword(s):  
Comparative Analysis ◽  
Computer Aided Design ◽  
Residual Life ◽  
Probabilistic Approach ◽  
Automated System ◽  
Industrial Building ◽  
Normative Values ◽  
Distribution Law ◽  
Advantages And Disadvantages ◽  
Industrial Buildings

In terms of developing automated system of calculating and forecasting the residual life of industrial buildings the article compares the advantages and disadvantages of reliability models of industrial buildings. The scheme of examining mode of deformation of an industrial building has been created. Realization of successive actions helps to determine the terms of achievement of the limiting conditions of an industrial building, to estimate the reserve strength of its carcass, and to search for changes in the amplitude values of the displacements in the calculated points, according to the results of comparative analysis of corresponding values in different periods of industrial building operation at a constant value of the generalized load. There has been carried out comparative analysis of computer-aided design systems that revealed the need to develop the proper software product specialized in calculating the work of industrial structures equipped with electric bridge cranes, with a whole complex of disturbing effects. According to the results of calculation scheme there was developed a summary algorithm which implemented the possibility of solving direct, inverse and predictive problems, as well as realizing probabilistic approach as most appropriate for random nature of man-made and natural impact, and for the conditions of their perception. Summary algorithm generates the values of crane loads in the form of continuous random values in accordance with the distribution law for the given parameters of expectation and mean-square deviation. It enables to carry out comparative analysis of the obtained probabilistic values and results of the calculation of the normative values of loads under constant conditions of the system operation. This algorithm is the basis of the development of the settlement and software complex "ASR-2018".

scholarly journals MODERN APPROACHES TO RESIDUAL LIFE CALCULATION OF FLEXURAL STEEL CONCRETE ELEMENTS WITH CORROSION DAMAGE

2019 ◽  
pp. 88-100
Author(s):  
G. A. Smolyago ◽  
N. V. Frolov
Keyword(s):  
Residual Life ◽  
Limit State ◽  
Concrete Structures ◽  
Corrosion Damage ◽  
Computational Techniques ◽  
Ultimate Limit State ◽  
Design Standards ◽  
Advantages And Disadvantages ◽  
Construction Design ◽  
Concrete Elements

The article is devoted to problems of ensuring durability of steel concrete elements of buildings. It is shown that durability depends on their residual and service life. Normalizing of the latter is generalized, not sufficiently substantiated and non-regulatory. Computational techniques to assess the construction durability are not yet available. Actual and informative is determining the residual life of steel concrete structures. It was noted that the reason for the reduction in the carrying capacity of steel concrete structures and, accordingly, the residual life is corrosion damage of concrete and reinforcement due to an aggressive environment. This paper analyzes the modern methods of calculating residual life of flexural elements with corrosion, identifies their advantages and disadvantages in building inspection. The residual life should be determined on the basis of field surveys, when the maximum corrosion damage is found in various design sections. The physical and statistical approach is the most promising and acceptable for assessing and predicting the residual life of flexural steel concrete elements. The value of the residual life is proposed to be established with regard to reliability coefficient. Considering the ever increasing cases of early loss of bearing capacity of steel concrete structures due to corrosion damage, it is advisable to include mandatory requirements in construction design standards of calculating on a new ultimate limit state.  

scholarly journals The Italian Guidelines on Risk Classification and Management of Bridges: Applications and Remarks on Large Scale Risk Assessments

2021 ◽  
Vol 6 (8) ◽  
pp. 111
Author(s):  
Giuseppe Santarsiero ◽  
Angelo Masi ◽  
Valentina Picciano ◽  
Andrea Digrisolo
Keyword(s):  
Large Scale ◽  
Residual Life ◽  
Well Being ◽  
Transportation Systems ◽  
Risk Classification ◽  
Public Image ◽  
Normal Operation ◽  
Advantages And Disadvantages ◽  
Funds Allocation ◽  
Existing Bridges

Bridges are essential for guaranteeing the functioning of transportation systems since their failure can cause serious threats to the safety, well-being and economy of modern communities, especially in emergency conditions. Following recent bridge failures, among which include the Morandi bridge in 2018, specific guidelines on risk classification and management, safety assessment and monitoring of existing bridges have been issued in Italy by the Minister of Infrastructure as a mandatory code. They pay particular attention to the evaluation of the residual life span of critical transportation infrastructure dating back to the 1950s and 1960s of the last century. Being a newly issued tool, the Guidelines need to be applied and tested in order to find possible drawbacks and to point out the main factors influencing their results. Therefore, in this study, after a short description of the Italian Guidelines, pointing out some differences with other approaches adopted worldwide, some advantages and disadvantages are discussed by an application to a bridge stock located in the Basilicata region (Italy). Data needed to apply the Guidelines are gathered by a purposely set up procedure that exploits existing databases on road infrastructure (OpenStreetMap) complemented by additional data retrieved by means of public image repositories (Google Street View). By accounting for the qualitative nature of the risk classification results obtained by applying the lower analysis levels of the Guidelines, a prioritization method is proposed for ranking bridges for higher assessment levels and possible interventions, as well as consequent funds allocation. The application shows that the Guidelines’ approach tends to provide conservative results. In fact, even in case of bridges with low degradation levels, the final risk classification induces actions undertaken for preliminary or detailed assessment; thus, normal operation (with periodic inspections) would not be possible anymore.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

A conduction-cooled stage for high-resolution Cryo-SEM

1992 ◽  
Vol 50 (2) ◽  
pp. 1282-1283
Author(s):  
John G. Sheehan
Keyword(s):  
High Resolution ◽  
Liquid Nitrogen ◽  
Mechanical Stability ◽  
Cooling System ◽  
Cold Trap ◽  
Nitrogen Gas ◽  
Particulate Suspensions ◽  
Advantages And Disadvantages ◽  
Convection Cooling ◽  
Styrene Butadiene

The goal is to examine with high resolution cryo-SEM aqueous particulate suspensions used in coatings for printable paper. A metal-coating chamber for cryo-preparation of such suspensions was described previously. Here, a new conduction-cooling system for the stage and cold-trap in an SEM specimen chamber is described. Its advantages and disadvantages are compared to a convection-cooling system made by Hexland (model CT1000A) and its mechanical stability is demonstrated by examining a sample of styrene-butadiene latex.In recent high resolution cryo-SEM, some stages are cooled by conduction, others by convection. In the latter, heat is convected from the specimen stage by cold nitrogen gas from a liquid-nitrogen cooled evaporative heat exchanger. The advantage is the fast cooling: the Hexland CT1000A cools the stage from ambient temperature to 88 K in about 20 min. However it consumes huge amounts of liquid-nitrogen and nitrogen gas: about 1 ℓ/h of liquid-nitrogen and 400 gm/h of nitrogen gas. Its liquid-nitrogen vessel must be re-filled at least every 40 min.

Computer simulations for the TEM bend contour technique

1996 ◽  
Vol 54 ◽  
pp. 134-135
Author(s):  
Vladimir Yu. Kolosov ◽  
Anders R. Thölén
Keyword(s):  
Computer Simulations ◽  
Real Space ◽  
Advantages And Disadvantages ◽  
Short Overview ◽  
Diffraction Contrast ◽  
Beam Method ◽  
Convergent Beam ◽  
Contour Technique

In this paper we give a short overview of two TEM applications utilizing the extinction bend contour technique (BC) giving the advantages and disadvantages; especially we consider two areas in which the BC technique remains unique. Special attention is given to an approach including computer simulations of TEM micrographs.BC patterns are often observed in TEM studies but are rarely exploited in a serious way. However, this type of diffraction contrast was one of the first to be used for analysis of imperfections in crystalline foils, but since then only some groups have utilized the BC technique. The most extensive studies were performed by Steeds, Eades and colleagues. They were the first to demonstrate the unique possibilities of the BC method and named it real space crystallography, which developed later into the somewhat similar but more powerful convergent beam method. Maybe, due to the difficulties in analysis, BCs have seldom been used in TEM, and then mainly to visualize different imperfections and transformations.

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