scholarly journals Evaluation of the Accident Rate of a Plant Equipped with an Aging Single Protective Channel by the Method of Supplementary Variables

2021 ◽  
Vol 22 (4) ◽  
pp. 533-543
Author(s):  
L. G. Oliveira ◽  
D. G. Teixeira ◽  
P. F. Frutuoso e Melo
Keyword(s):  
Finite Differences ◽  
System Of Equations ◽  
Accident Rate ◽  
Industrial Facilities ◽  
Failure Times ◽  
Supplementary Variables ◽  
Protective System ◽  
Integral Differential Equations ◽  
Ordinary Integral ◽  
Protective Systems

This work calculates the reliability of protective systems of industrial facilities, such as nuclear, to analyze the case of equipment subject to aging, important in the extension of the qualified life of the facilities. By means of the method of supplementary variables, a system of partial and ordinary integral-differential equations was developed for the probabilities of a protective system of an aging channel. The system of equations was solved by finite differences. The method was validated by comparison with channel results with exponential failure times. The method of supplementary variables exhibits reasonable results for values of reliability attributes typical of industrial facilities.

Protective Systems for Gas Turbines in Industry

1974 ◽  
Author(s):  
J. N. Shinn
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Comprehensive System ◽  
Heavy Duty ◽  
Protective System ◽  
System Philosophy ◽  
Heavy Duty Gas Turbine ◽  
Protective Systems

Modern heavy-duty gas turbine installations employ a comprehensive system of protective circuits to provide needed equipment protection without jeopardizing plant reliability. The design of these circuits and the overall protective system philosophy are discussed to illustrate how protection and reliability are maximized. Experience gained to date on the application of these protective circuits also is reviewed.

scholarly journals Development and performance evaluation of large-scale auxetic protective systems for localised impulsive loads

2019 ◽  
Vol 10 (3) ◽  
pp. 390-417 ◽  
Author(s):  
Alex Remennikov ◽  
Dulara Kalubadanage ◽  
Tuan Ngo ◽  
Priyan Mendis ◽  
Gursel Alici ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
High Performance ◽  
Sandwich Panel ◽  
Sandwich Panels ◽  
Dynamic Loads ◽  
Low Density Polyethylene ◽  
Honeycomb Core ◽  
Protective System ◽  
Static And Dynamic Loads ◽  
Protective Systems

Cellular core structures with a negative Poisson’s ratio, also known as auxetic core structures, are gaining attention due to their unique performance in sandwich panel systems for protecting critical infrastructures and military vehicles that are at high risk of blast and impact loads due to accidental and deliberate events. To help develop a high-performance protective system, this article outlines the performance evaluation of five different auxetic cell configurations based on a quantitative/qualitative review of an experimental load–deformation relationship of three-dimensional-printed auxetic panels from nylon plastics and the overall performance evaluation of metallic re-entrant honeycomb core sandwich panels as one type of lightweight protective system under static and dynamic loads via experimental testing and numerical simulations. The re-entrant honeycomb design displayed the most consistent auxetic behaviour. Quasi-static compression and drop hammer impact tests were performed using the proposed full-scale sandwich panel design with two different configurations as a protective system for concrete wall structures in combination with plastic face plates. The effect of the internal angle of the re-entrant honeycomb design and the effect of the core material under static and dynamic loads were evaluated using full-scale sandwich panels. Furthermore, two separate materials – acrylonitrile butadiene styrene and low-density polyethylene – were used as face plates, and the low-density polyethylene was effective for lightweight and smooth load transferring and distribution into the auxetic core. Auxetic panel deformation under static and dynamic load was examined using a normal speed camera and high-speed video recording data and all auxetic panels indicated excellent systematic crushing behaviour with drawing materials into the load path to effectively resist the impact load. Numerical simulations were performed using LS-DYNA and indicated good agreement with the experimental results. Finally, protective systems utilising sandwich panels with a re-entrant honeycomb core indicated strong potential for the development of high-performance lightweight impact-resistant protective systems.

scholarly journals The effect of Zn-Ni sublayers on the corrosion behaviour and thermal stability of epoxy coatings electrodeposited on steel

2000 ◽  
Vol 65 (12) ◽  
pp. 923-933 ◽  
Author(s):  
Vesna Miskovic-Stankovic ◽  
Jelena Bajat ◽  
Miodrag Maksimovic ◽  
Zorica Kacarevic-Popovic
Keyword(s):  
Thermal Stability ◽  
Pulse Current ◽  
Corrosion Behaviour ◽  
Epoxy Coating ◽  
Epoxy Coatings ◽  
Corrosion Stability ◽  
Ni Alloys ◽  
Protective System ◽  
Thermal Stability Of ◽  
Protective Systems

The electrochemical and transport properties, as well as the thermal stability of epoxy coatings electrodeposited on steel and steel modified by Zn-Ni alloys were investigated during exposure to 3% NaCl. The Zn-Ni alloys were electrodeposited on steel using direct and pulse current. From the time dependence of the pore resistance of the epoxy coating (impedance measurements), the diffusion coefficient of water through the epoxy coating (gravimetric liquid sorption measurements) and the thermal stability of the epoxy coating (thermogravimetric analysis), it was shown that Zn-Ni sublayers significantly improve the corrosion stability of a protective system based on an epoxy coating. The values of the pore resistance were almost unchanged over a long period of immersion time for epoxy coatings on steel modified by Zn-Ni alloys, inidicating the great stability of these protective systems.

scholarly journals Riser and well casing analysis during drift-off: a coupled solution in the time domain

2022 ◽  
Author(s):  
Fabiano Guimarães
Keyword(s):  
Time Domain ◽  
Finite Differences ◽  
Coupled System ◽  
Computational Effort ◽  
System Of Equations ◽  
Recursive Method ◽  
Coupled Equations ◽  
The Time Domain ◽  
The Impact ◽  
Fully Coupled

AbstractOne of the most serious incidents that can occur in offshore drilling and exploration is damage to the well structure and subsea components which can result in uncontrolled hydrocarbon release to the environment and present a safety hazard to rig personnel. Over decades, there have been substantial developments to the mathematical models and algorithms used to analyze the stresses on the related structure and to define the operational and integrity windows in which operations can proceed safely and where the mechanical integrity of the well is preserved. The purpose of this work is to present a time-domain solution to the system of equations that model the dynamic behavior of the riser and casing strings, when connected for well drilling/completion during the event of drift-off of the rig. The model combines a solution using finite differences for the riser dynamics and a recursive method to analyze the behavior of the casing in the soil. It allows for the coupling between the equations related to the riser and casing and for the coupling with the equations that describe the dynamics of the rig when station keeping capabilities are lost. The use of the forward–backward finite-differences coupled with the recursive method does not require linearization of the forces acting on the structure making it an ideal methodology for riser analysis while improving convergence. The findings of this study can help improve understanding of the impact of the watch circle limits to riser/well integrity, whether these limits are set based on a quasi-static drive-off/drift-off or fully dynamic. The gain in accuracy in using the fully coupled equations of drift-off dynamics, where there is interaction between the rig and the top of the riser during drive-off/drift-off, is evaluated, and the effects of varying the riser top tension and the compressive loads on the casing string are also analyzed. In particular, it is shown that the results of the fully coupled system of equations representing the dynamics of the riser and casing during drift-off/drive-off are less conservative than the quasi-static approach. Another important finding is that the gain in accuracy in coupling the top of the riser and the rig during drift-off/drive-off is not substantial, which indicates that solving separately the rig dynamics equations and the riser-casing equations is an approach that provides reasonable results with less computational effort. The model can also be used to evaluate wellhead and casing fatigue during the life of the intervention. Finally, the model limitations are discussed.

scholarly journals SCIENTIFICALLY SUBSTANTIATED APPROACHES TO ECOLOGIZATION OF AGRICULTURE IN TRANSCARPATHIA

2021 ◽  
Vol 29 ◽  
pp. 62-73
Author(s):  
O. MATIEGA ◽  
I. BALYAN ◽  
L. ZHUKOVSKA
Keyword(s):  
Soil Fertility ◽  
Crop Production ◽  
Land Reclamation ◽  
Plant Protection ◽  
Integral System ◽  
Pests And Diseases ◽  
Agriculture Soil ◽  
Physical Chemical ◽  
Protective System ◽  
Protective Systems

The article focuses on scientifically substantiated approaches to ecologization of agriculture in Transcarpathia: introducing soil-protective system of agriculture with a contour-land-reclamation organization of the territory, developing measures on physical, chemical, radiation pollution of soil, biologization of agriculture, including protective systems against pests and diseases, obtaining ecologically pure and biologically valuable crop production. Keywords: ecologization of agriculture, erosion, soil-protective system of agriculture, soil fertility, washing out of nutriments, integral system of plant protection.

Lighting of Engineering Structures and Industrial Facilities New Aspects of the Topic

2018 ◽  
pp. 29-36
Author(s):  
Nikolai I. Shepetkov ◽  
George N. Cherkasov ◽  
Vladimir A. Novikov
Keyword(s):  
Fundamental Problem ◽  
Lighting Design ◽  
Aesthetic Value ◽  
Engineering Structures ◽  
Industrial Facilities ◽  
Artificial Lighting ◽  
Industrial Structures ◽  
Design Solutions ◽  
Architectural Lighting ◽  
The Aesthetic

This paper considers the fundamental problem of artificial lighting in various types and scales of industrial facilities, focusing on exterior lighting design solutions. There is a lack of interest from investors, customers and society in high­quality lighting design for industrial facilities in Russia, which in many cities are very imaginative structures, practically unused in the evening. Architectural lighting of various types of installations is illustrated with photographs. The purpose of the article is to draw attention to the aesthetic value of industrial structures, provided not only by the architectural, but also by a welldesigned lighting solution.

Canonical Submersion and Lie Homomorphisms Normal Subgroup

2020 ◽  
Vol 23 (1) ◽  
pp. 97-101
Author(s):  
Mikhail Petrichenko ◽  
Dmitry W. Serow
Keyword(s):  
Normal Subgroup ◽  
Canonical System ◽  
System Of Equations ◽  
Core Group ◽  
The Core ◽  
Switch Group

Normal subgroup module f (module over the ring F = [ f ] 1; 2-diffeomorphisms) coincides with the kernel Ker Lf derivations along the field. The core consists of the trivial homomorphism (integrals of the system v = x = f (t; x )) and bundles with zero switch group Lf , obtained from the condition ᐁ( ω × f ) = 0. There is the analog of the Liouville for trivial immersion. In this case, the core group Lf derivations along the field replenished elements V ( z ), such that ᐁz = ω × f. Hence, the core group Lf updated elements helicoid (spiral) bundles, in particular, such that f = ᐁU. System as an example Crocco shown that the canonical system does not permit the trivial embedding: the canonical system of equations are the closure of the class of systems that permit a submersion.

LIQUIDUS THERMO-BAROMETER FOR THE MODELING OF MAGNETITE — MELT EQUILIBRIUM

2018 ◽  
pp. 71-80
Author(s):  
N. S. Aryaeva ◽  
E. V. Koptev-Dvornikov ◽  
D. A. Bychkov
Keyword(s):  
Experimental Data ◽  
Liquidus Temperature ◽  
Vertical Structure ◽  
Maximum Error ◽  
Silicate Melt ◽  
System Of Equations ◽  
Wide Range ◽  
Basaltic Melts ◽  
Multidimensional Statistics

A system of equations of thermobarometer for magnetite-silicate melt equilibrium was obtained by method of multidimensional statistics of 93 experimental data of a magnetite solubility in basaltic melts. Equations reproduce experimental data in a wide range of basalt compositions, temperatures and pressures with small errors. Verification of thermobarometers showed the maximum error in liquidus temperature reproducing does not exceed ±7 °C. The level of cumulative magnetite appearance in the vertical structure of Tsypringa, Kivakka, Burakovsky intrusions predicted with errors from ±10 to ±50 m.

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