Quantity and Quality Benefits of in-Service Invasive Cleaning of Trunk Mains

Abstract. Trunk mains are high risk critical infrastructure where poor performance can impact on large numbers of customers. Both quantity (e.g. hydraulic capacity) and quality (e.g. discolouration) of trunk main performance are affected by asset deterioration in the form of particle accumulation at the pipe wall. Trunk main cleaning techniques are therefore desirable to remove such material. However, little is quantified regarding the efficacy of different maintenance interventions or longer-term changes following such cleaning. This paper presents an assessment of quantity and quality performance of a trunk main system pre, post and for 12 months following cleaning using pigging with ice slurry. Hydraulic calibration showed a 7 times roughness height reduction after ice slurry pigging, evidencing substantially improved hydraulic capacity and reduced headloss. Turbidity response due to carefully imposed shear stress increase remained significant after the cleaning intervention, showing that relatively loose material had not been fully removed from the pipe wall. Overall the results demonstrate that cleaning by pigging with ice slurry can be beneficial for quantity performance, but care and further assessment may be necessary to realise the full quality benefits.

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Human factor in emergency occurrence at NPP during the pandemic COVID-19: new potential risks and recommendations to minimize them

E3S Web of Conferences ◽

10.1051/e3sconf/202128009013 ◽

2021 ◽

Vol 280 ◽

pp. 09013

Author(s):

Oleksandr Popov ◽

Anna Iatsyshyn ◽

Norbert Molitor ◽

Andrii Iatsyshyn ◽

Yevhen Romanenko ◽

...

Keyword(s):

Mental Health ◽

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Critical Infrastructure ◽

Well Being ◽

Psychological Support ◽

Negative Consequences ◽

Large Numbers ◽

Potential Risks

COVID-19 pandemic is an emergency that spread across the planet. It threatens lives and health of the population, with many dead and injured. Also, during pandemic there was (and continues to be) a violation of normal living conditions, significant material damage to economies of different countries. Quarantine restrictions affected social, educational, cultural and spiritual spheres of society. There is an urgent threat to operation of critical infrastructure as the pandemic led to large numbers of hospitalized or self-isolated people and being treated at home. At present, the operation of critical infrastructure, and in particular nuclear power plants, is strategically important for the proper functioning of any country. Also, the research describes causes of emergencies at nuclear power plants and identifies another factor - the mass disease of NPP personnel or their relatives on COVID-19. It is determined that timely detection and appropriate work to restore mental health during the pandemic is no less important area of work along with providing medical care to population. Stress associated with uncertainty, threat to health, can have negative consequences for well-being and mental health of workers. Depression, emotional exhaustion, anxiety, irritability, suicidal thoughts, etc. can also be consequences. Socio-psychological support especially for critical infrastructure workers is important to promote mental health during COVID-19 pandemic. Recommendations for socio-psychological support of NPP personnel were developed. Specialized mobile applications are described as convenient and economical way for primary psychological care.

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Resilience or robustness: identifying topological vulnerabilities in rail networks

Royal Society Open Science ◽

10.1098/rsos.181301 ◽

2019 ◽

Vol 6 (2) ◽

pp. 181301 ◽

Cited By ~ 14

Author(s):

Alessio Pagani ◽

Guillem Mosquera ◽

Aseel Alturki ◽

Samuel Johnson ◽

Stephen Jarvis ◽

...

Keyword(s):

Large Scale ◽

Critical Infrastructure ◽

Poor Performance ◽

Feedback Loops ◽

Consumer Experience ◽

Transport Networks ◽

Agent Based ◽

National Importance ◽

Topological Measures ◽

Cascade Effects

Many critical infrastructure systems have network structures and are under stress. Despite their national importance, the complexity of large-scale transport networks means that we do not fully understand their vulnerabilities to cascade failures. The research conducted through this paper examines the interdependent rail networks in Greater London and surrounding commuter area. We focus on the morning commuter hours, where the system is under the most demand stress. There is increasing evidence that the topological shape of the network plays an important role in dynamic cascades. Here, we examine whether the different topological measures of resilience (stability) or robustness (failure) are more appropriate for understanding poor railway performance. The results show that resilience, not robustness, has a strong correlation with the consumer experience statistics. Our results are a way of describing the complexity of cascade dynamics on networks without the involvement of detailed agent-based models, showing that cascade effects are more responsible for poor performance than failures. The network science analysis hints at pathways towards making the network structure more resilient by reducing feedback loops.

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Possible IED Threat To Airport Premises During Security X-Ray Inspection

TRANSACTIONS of the VŠB – Technical University of Ostrava Safety Engineering Series ◽

10.1515/tvsbses-2015-0005 ◽

2015 ◽

Vol 10 (1) ◽

pp. 31-37

Author(s):

Stanislav Lichorobiec ◽

Karla Barčová

Keyword(s):

Critical Infrastructure ◽

Terrorist Attack ◽

Air Transport ◽

Risk Category ◽

X Rays ◽

X Ray ◽

High Risk Category ◽

Large Numbers ◽

Security Checks ◽

Very High

Abstract The premises of international airports in CR are major air transport hubs as well as key elements of critical infrastructure, belonging to the very high risk category. Any infringement leading to limitation or complete shutdown would cause considerable economic and psychological damage. The most important task is to ensure high quality and reliable physical and technical protection of the airport, because especially in the summer months these areas collect large numbers of people and a possible terrorist attack could be fatal. This paper focuses on assessing the possibilities of solving the problem of IEDs hidden in travel luggage, and their initiation by X-rays during security checks.

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Numerical Simulation of Slurry flow in horizontal pipe based on CFD-DEM

MATEC Web of Conferences ◽

10.1051/matecconf/202030601007 ◽

2020 ◽

Vol 306 ◽

pp. 01007

Author(s):

Jinchao Fan ◽

Benchun Yao ◽

Yi Hao ◽

Shimin Zhang ◽

Xiaoxiao Zhu

Keyword(s):

Numerical Simulation ◽

Particle Size ◽

Pressure Loss ◽

Pipe Wall ◽

Flow Characteristics ◽

Cleaning Process ◽

Slurry Flow ◽

Horizontal Pipe ◽

Particle Accumulation ◽

Dem Model

In this paper, we propose a novel pipeline cleaning method utilizing slurry. The reason why slurry can be used for pipeline cleaning is that the collisions between the particles and the contaminant in the pipe wall can enhance the cleaning effect. A slurry with polypropylene particles embedded in water is used to cleaning a horizontal pipe is conducted to realize this method. Because the flow characteristics of the slurry is crucial for the cleaning process, it is valuable to conduct a simulation and investigate the influence of several different factors including the convey velocity and the particle size. A 3D CFD-DEM model has been established. The indicators including pressure loss, particle accumulation level at the top of the pipe are choses to characterize the slurry flow and the influence of convey velocity and particle size has been investigated accordingly. In addition, an effective method is proposed to determine the critical convey velocity for each size of the particle.

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Cybersecurity of Railway Network Management and Partitioning

Problemy Kolejnictwa - Railway Reports ◽

10.36137/1896e ◽

2020 ◽

Vol 64 (189) ◽

pp. 125-131

Author(s):

Jan Procházka ◽

Petr Novobilsky ◽

Dana Procházkova

Keyword(s):

Critical Infrastructure ◽

Data Communication ◽

Physical Space ◽

Transport Infrastructure ◽

Security Requirements ◽

Large Area ◽

Railway Network ◽

Large Numbers ◽

High Assurance ◽

Cyberphysical System

The railway transport infrastructure ensures the transfer of large numbers of people and cargo every day. The importance of the railway in terms of ensuring the serviceability of the territory makes it a critical infrastructure. We can observe the development of the use of IT technologies on railway, as in all areas of the human system. The management of the railway as a physical system needs to be superseded by management of the railway as a cyberphysical system. The railway infra-structure has a large area of attack in both, physical space and cyber space. Multiple Independent Levels of Security (MILS) can meet the high system security requirements. The MILS is a high-assurance security architecture based on the concepts of separation and controlled information flow. The article discusses the possibilities of using the MILS platform in the data communication system and the control system of the railway. Keywords: Cyber Physical Systems, Critical Infrastructures, Multiple Independent Levels of Security

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Cybersecurity, Cloud, and Critical Infrastructure

Cloud Computing Law ◽

10.1093/oso/9780198716662.003.0011 ◽

2021 ◽

pp. 382-418

Author(s):

Johan David Michels ◽

Ian Walden

Keyword(s):

Supply Chain ◽

General Public ◽

Critical Infrastructure ◽

Service Providers ◽

Regulatory Framework ◽

Cloud Services ◽

Digital Service ◽

Large Numbers ◽

Essential Services ◽

Cloud Providers

This chapter addresses the emerging regulatory framework for cybersecurity and considers its implications for the provision and use of cloud services. It focuses on cybersecurity measures that target service providers on whom large numbers of consumers and businesses depend, rather than measures triggered by the nature of the data being processed. The chapter first reviews the main elements of the Network and Information Systems (NIS) Directive, one of the principal cybersecurity instruments in the EU. It then examines how cloud providers are regulated as Digital Service Providers (DSPs) under the NIS Directive. Cloud providers are also indirectly regulated by the NIS Directive, when they form part of the supply chain of a regulated operator of essential services (OES), the primary target of the measure. The chapter also looks at other EU legal instruments that impose cybersecurity requirements in relation to specific sectors and activities. Finally, it considers concerns that this new regulatory framework may lead to only incremental improvements in the cybersecurity of Europe's critical infrastructure and digital services, while generating substantial compliance activity, aimed at placating regulators and reassuring the general public.

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A novel optimization approach for sub-hourly unit commitment with large numbers of units and virtual transactions

10.36227/techrxiv.14538270.v1 ◽

2021 ◽

Author(s):

JIANGHUA WU ◽

Peter Luh ◽

Yonghong Chen ◽

Mikhail Bragin ◽

Bing Yan

Keyword(s):

Unit Commitment ◽

Computation Time ◽

Poor Performance ◽

Convergence Condition ◽

Branch And Cut ◽

Ordinal Optimization ◽

Optimization Approach ◽

Power System Operations ◽

Large Numbers ◽

Practice Method

Unit Commitment (UC) is an important problem in power system operations. It is traditionally scoped for 24 hours with one-hour time intervals. To improve system flexibility by accommodating the increasing net-load variability, sub-hourly UC has been suggested. Such a problem is larger and more complicated than hourly UC because of the increased number of periods and reduced unit ramping capabilities per period. The computational burden is further exacerbated for systems with large numbers of virtual transactions leading to dense transmission constraints matrices. Consequently, the state-of-the-art and practice method, branch-and-cut (B&C), suffers from poor performance. In this paper, our recent Surrogate Absolute-Value Lagrangian Relaxation (SAVLR) is enhanced by embedding ordinal-optimization concepts for a drastic reduction in subproblem solving time. Rather than formally solving subproblems by using B&C, subproblem solutions that satisfy SAVLR’s convergence condition are obtained by modifying solutions from previous iterations or solving crude subproblems. All virtual transactions are included in each subproblem to reduce major changes in solutions across iterations. A parallel version is also developed to further reduce the computation time. Testing on MISO’s large cases demonstrates that our ordinal-optimization embedded approach obtains near-optimal solutions efficiently, is robust, and provides a new way on solving other MILP problems.

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A novel optimization approach for sub-hourly unit commitment with large numbers of units and virtual transactions

10.36227/techrxiv.14538270 ◽

2021 ◽

Author(s):

JIANGHUA WU ◽

Peter Luh ◽

Yonghong Chen ◽

Mikhail Bragin ◽

Bing Yan

Keyword(s):

Unit Commitment ◽

Computation Time ◽

Poor Performance ◽

Convergence Condition ◽

Branch And Cut ◽

Ordinal Optimization ◽

Optimization Approach ◽

Power System Operations ◽

Large Numbers ◽

Practice Method

Unit Commitment (UC) is an important problem in power system operations. It is traditionally scoped for 24 hours with one-hour time intervals. To improve system flexibility by accommodating the increasing net-load variability, sub-hourly UC has been suggested. Such a problem is larger and more complicated than hourly UC because of the increased number of periods and reduced unit ramping capabilities per period. The computational burden is further exacerbated for systems with large numbers of virtual transactions leading to dense transmission constraints matrices. Consequently, the state-of-the-art and practice method, branch-and-cut (B&C), suffers from poor performance. In this paper, our recent Surrogate Absolute-Value Lagrangian Relaxation (SAVLR) is enhanced by embedding ordinal-optimization concepts for a drastic reduction in subproblem solving time. Rather than formally solving subproblems by using B&C, subproblem solutions that satisfy SAVLR’s convergence condition are obtained by modifying solutions from previous iterations or solving crude subproblems. All virtual transactions are included in each subproblem to reduce major changes in solutions across iterations. A parallel version is also developed to further reduce the computation time. Testing on MISO’s large cases demonstrates that our ordinal-optimization embedded approach obtains near-optimal solutions efficiently, is robust, and provides a new way on solving other MILP problems.

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The Nanoscale Frontier

Mechanical Engineering ◽

10.1115/1.2016-nov-3 ◽

2016 ◽

Vol 138 (11) ◽

pp. 45-47

Author(s):

Jeffrey Winters

Keyword(s):

Carbon Nanotubes ◽

Energy Density ◽

Pipe Wall ◽

High Energy ◽

Convective Transport ◽

High Energy Density ◽

Water Molecules ◽

Nanoscale Structures ◽

Large Numbers ◽

Channel Surface

This article presents an overview of various aspects of nanoscale technology. As opposed to the macroscale, where water molecules next to a pipe wall have zero velocity, in nanochannels, fluid molecules slip at the channel surface, experiencing an enhanced convective transport. Nanotechnology can also help us alter natural designs. Carbon nanotubes act like a reinforcement to give synthetic tissue the strength, stiffness, and viscoelastic performance of natural membranes. In order to store macroscopically significant amounts of energy, one needs to deform large numbers of carbon nanotubes. It is more challenging still to deform them in a way that maintains high-energy density of overall system. Micro- and nanoscale structures have given us capabilities to interact with cells and pathogens at their level as never before and helped us understand how they live, grow, multiply, differentiate, and die.

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