Analytical method for parameterizing the random profile components of nanosurfaces imaged by atomic force microscopy

The functional properties of many technological surfaces in biotechnology, electronics, and mechanical engineering depend to a large degree on the individual features of their nanoscale surface texture, which in turn are a function of the surface manufacturing process. Among these features, the surface irregularities and self-similarity structures at different spatial scales, especially in the range of 1 to 100 nm, are of high importance because they greatly affect the surface interaction forces acting at a nanoscale distance. An analytical method for parameterizing the surface irregularities and their correlations in nanosurfaces imaged by atomic force microscopy (AFM) is proposed. In this method, flicker noise spectroscopy - a statistical physics approach - is used to develop six nanometrological parameters characterizing the high-frequency contributions of jump- and spike-like irregularities into the surface texture. These contributions reflect the stochastic processes of anomalous diffusion and inertial effects, respectively, in the process of surface manufacturing. The AFM images of the texture of corrosion-resistant magnetite coatings formed on low-carbon steel in hot nitrate solutions with coating growth promoters at different temperatures are analyzed. It is shown that the parameters characterizing surface spikiness are able to quantify the effect of process temperature on the corrosion resistance of the coatings. It is suggested that these parameters can be used for predicting and characterizing the corrosion-resistant properties of magnetite coatings.Comment: 7 pages, 3 figures, 2 tables; to be published in Analys

Предсказательное техническое обслуживание трубопроводов на основе экспресс-оценки степени опасности дефектов

The paper describes a tested and proven practical methodology of predictive maintenance of pipelines with two types of defects — “loss of metal” and “pipe wall lamination”, detected by the ILI technology. The laminations are caused by the steel and pipe manufacturing technology, and may also appear during pipeline operation. The laminations can be further classified as metallurgical laminations, hydrogen induced cracking (HIC), non-metallic inclusions, and such. For the defects of the “pipe wall lamination” type the assessment of their level of danger is conducted only after they are converted to surface “loss of metal” type defects. The paper presents models on how to adequately convert the “pipe wall lamination” type of defects to the “loss of metal” type defects. A methodology is described on how to rank the defects according to their level of danger (with respect to the rupture type of failure), and how to perform the probabilistic assessment of the pipeline residual life. In order to account for “leak” and “rupture” types of failure, a computer based express assessment is developed of the level of severity of each defect. This defect assessment is based on graphs, which restrict the permissible sizes of defects and allow making operative decisions as to which maintenance measures should be taken, regarding pipeline segment as a whole. The pipeline defects are ranked according to their potential danger, which depends on their location on the graphs. The probabilistic assessment of the residual pipeline life is performed taking into account the stochastic nature of defect growth. In order to achieve this, the maximal γ-percentile corrosion rate is defined over all detected defects. As the main decision parameter the gamma-percent operating time is chosen. It is characterized by: the safe operating time, and the percentile probability that during this time the pipeline limit state will not be reached. A detailed example of implementation of the described methodology to a real product pipeline segment operating in a severe corrosion environment is given. The economical effect of the implementation is outlined.Статья описывает проверенную практическую методологию предсказательного технического обслуживания (мейнтенанса) трубопроводов с двумя типами дефектов — «потеря металла» и «несплошность металла стенки трубы — расслоение», обнаруженных с помощью технологии внутритрубной диагностики (ВТД). Несплошности металла стенки трубы возникают в процессе сталеплавильного и прокатного производства, а также в процессе эксплуатации. К этим дефектам относятся: металлургические расслоения, водородные расслоения, закаты и плотные неметаллические включения. Для дефектов, относящихся к этому типу, оценка степени опасности производится только после приведения дефекта к поверхностному дефекту типа «потеря металла». В работе представлены модели приведения несплошности металла к поверхностным дефектам типа «потеря металла». Методика описывает способ ранжировки дефектов по уровню их опасности (относительно отказа типа «разрыв») и вероятностную оценку остаточного ресурса трубопровода. Для учета обоих сценариев отказа «течь» и «разрыв» строится компьютерная экспресс-оценка степени опасности дефектных участков трубопровода путем построения графиков, ограничивающих размеры дефектов трубопровода и позволяющих принимать оперативные решения о мерах по дальнейшей эксплуатации трубопровода. Осуществляется классификация потенциальной опасности дефектов трубопровода в зависимости от области их расположения на графиках. Расчет вероятностной оценки прогнозирования остаточного ресурса трубопровода проведен с учетом вероятностного подрастания дефектов. Для этого определяется максимальная, с заданной вероятностью γ, скорость коррозии по всем дефектам. В качестве основного показателя определяется гамма-процентный ресурс, задаваемый двумя численными значениями: наработкой и выраженной в процентах вероятностью того, что в течение этой наработки предельное состояние не будет достигнуто. Данная работа описывает пример применения описанной методологии к наземному участку трубопровода, транспортирующему сильнодействующий коррозионный конденсат. Также обсуждается экономический эффект от реализации представленной методологии

Macroeconomic Aspects of Maintenance Optimization of Critical Infrastructures

The main goal of maintenance is prevention, timely detection and elimination of failures and damage. From the point of view of critical infrastructures (CIs), the main purpose of their maintenance is to increase the safety of CIs and / or to ensure life safety. CIs should be optimal in terms of their purpose, cost, as a source of income and profit at all stages of their life cycle, and also acceptable in terms of possible loss of human lives or injuries. The paper considers the assessment of necessary optimal investments in the maintenance (time interval between subsequent maintenance), to increase the safety of life, the so-called life saving costs. The problem of limiting the threat to human life is as follows: “how much money is society ready and able to spend to reduce the likelihood of premature death”. A quantitative criterion of risk acceptance is used, in which the marginal cost of life saving is compared with social willingness to pay. This value is determined using the life quality index of population

Anomalous diffusion in the dynamics of complex processes

Anomalous diffusion, process in which the mean-squared displacement of system states is a non-linear function of time, is usually identified in real stochastic processes by comparing experimental and theoretical displacements at relatively small time intervals. This paper proposes an interpolation expression for the identification of anomalous diffusion in complex signals for the cases when the dynamics of the system under study reaches a steady state (large time intervals). This interpolation expression uses the chaotic difference moment (transient structural function) of the second order as an average characteristic of displacements. A general procedure for identifying anomalous diffusion and calculating its parameters in real stochastic signals, which includes the removal of the regular (low-frequency) components from the source signal and the fitting of the chaotic part of the experimental difference moment of the second order to the interpolation expression, is presented. The procedure was applied to the analysis of the dynamics of magnetoencephalograms, blinking fluorescence of quantum dots, and X-ray emission from accreting objects. For all three applications, the interpolation was able to adequately describe the chaotic part of the experimental difference moment, which implies that anomalous diffusion manifests itself in these natural signals. The results of this study make it possible to broaden the range of complex natural processes in which anomalous diffusion can be identified. The relation between the interpolation expression and a diffusion model, which is derived in the paper, allows one to simulate the chaotic processes in the open complex systems with anomalous diffusion.Comment: 47 pages, 15 figures; Submitted to Physical Review

Identification of earthquake precursors in the hydrogeochemical and geoacoustic data for the Kamchatka peninsula by flicker-noise spectroscopy

A phenomenological systems approach for identifying potential precursors in multiple signals of different types for the same local seismically active region is proposed based on the assumption that a large earthquake may be preceded by a system reconfiguration (preparation) at different time and space scales. A nonstationarity factor introduced within the framework of flicker-noise spectroscopy, a statistical physics approach to the analysis of time series, is used as the dimensionless criterion for detecting qualitative (precursory) changes within relatively short time intervals in arbitrary signals. Nonstationarity factors for chlorine-ion concentration variations in the underground water of two boreholes on the Kamchatka peninsula and geacoustic emissions in a deep borehole within the same seismic zone are studied together in the time frame around a large earthquake on October 8, 2001. It is shown that nonstationarity factor spikes (potential precursors) take place in the interval from 70 to 50 days before the earthquake for the hydrogeochemical data and at 29 and 6 days in advance for the geoacoustic data.Comment: 8 pages, 4 figures; to be published in Nat. Hazards Earth Syst. Sc

Transforming Yekaterinburg into a Safe, Resilient-Smart and Sustainable City

The initiative (since 2014) project described in this paper is a product of a joint innovative research and implementation effort of the Civil Engineering and Architecture Institute, Ural Federal University, the Science and Engineering Centre "Reliability and Safety of Large Systems and Machines", Ural Branch Russian Academy of Sciences (both Yekaterinburg), Start-up OptiCits, Barcelona, Spain and the Old Dominion University, Norfolk, VA, USA. The project is based on using the MAICS convergent technology [1] to create a versatile multi-purpose tool for optimizing the science and art of risk based governance of resilience-smart and sustainable city infrastructure and communities operating in usual and extreme conditions. The tool being developed is tailored to the needs of the City of Yekaterinburg-the capital of the Urals Region and allegedly the third most important and vibrant city of Russia. It is also being offered to the Yekaterinburg City Administration as an every-day decision-support work-tool and addendum to the Strategic Program "Yekaterinburg 2030 - a Safe City"[2] during preparation of the city for winning and conducting the World Expo-2025. Authors believe that the findings of this research would also be useful to the Sverdlovsk Oblast cities of every size and type of communities that inhabit them, including, first and foremost, Nizhny Tagil, Kamensk Uralsky, Serov, Pervouralsk, Revda, Verkhnyaya Pyshma, multiple mono-cities et al. The project also incorporates block-chain technology, smart contracts and digital currency as an effective tool for implementing the project. © 2018 Institute of Physics Publishing. All rights reserved