Combination of line sampling and important sampling for reliability assessment of buried pipelines

2018 ◽  
Vol 233 (2) ◽  
pp. 139-150
Author(s):  
Kong Fah Tee ◽  
Andrew Utomi Ebenuwa
Keyword(s):  
Water Table ◽  
Structural Reliability ◽  
Structural Parameters ◽  
Underground Water ◽  
Buried Pipe ◽  
Continuous Increase ◽  
Line Sampling ◽  
Sensitivity Assessment ◽  
The Impact ◽  
Underground Water Table

In this article, a novel approach for estimating the time-dependent reliability of a buried pipe under the impact of internal and external stresses by combining line sampling and important sampling is proposed. The stresses are analysed given the severe effect of corrosion on the performance of underground pipeline. The effect of corrosion during the design life of buried pipe decreases the capability of the pipe wall to sustain the stresses that occur internally or externally. Herein, the failure conditions of total axial stress and the ovality–stress due to point load in conjunction with the adverse effect of corrosion are examined using the proposed computational framework. The quantification of pipe failure due to these stresses is usually challenging because of the imprecision in the determination of the structural parameters. Therefore, the approach is used to capture and evaluate the influence of randomness behaviour of the parameters of pipe and soil in estimating the structural reliability. The proposed method can be applied to any structural engineering problems. In this study, a buried pipe under a roadway is examined and the effect of the underground water table on the performance of buried pipe over time is investigated. The outcome shows that a continuous increase in underground water table can aggravate the likelihood of the buried pipeline to fail. A parametric and sensitivity assessment of corrosion parameters shows their significant contribution to the probability of failure.

scholarly journals Evolution of Secondary Deformations Captured by Satellite Radar Interferometry: Case Study of an Abandoned Coal Basin in SW Poland

2019 ◽  
Vol 11 (3) ◽  
pp. 884 ◽  
Author(s):  
Jan Blachowski ◽  
Anna Kopec ◽  
Wojciech Milczarek ◽  
Karolina Owczarz
Keyword(s):  
Water Table ◽  
Radar Data ◽  
Underground Water ◽  
Coal Basin ◽  
Mining Areas ◽  
Surface Deformations ◽  
New Development ◽  
Satellite Radar ◽  
Underground Water Table ◽  
Coal Fields

The issue of monitoring surface motions in post-mining areas in Europe is important due to the fact that a significant number of post-mining areas lie in highly-urbanized and densely-populated regions. Examples can be found in: Belgium, the Czech Republic, France, Germany, the Netherlands, Spain, the United Kingdom, as well as the subject of this study, the Polish Walbrzych Hard Coal Basin. Studies of abandoned coal fields show that surface deformations in post-mining areas occur even several dozen years after the end of underground coal extraction, posing a threat to new development of these areas. In the case of the Walbrzych area, fragmentary, geodetic measurements indicate activity of the surface in the post-mining period (from 1995 onward). In this work, we aimed at determining the evolution of surface deformations in time during the first 15 years after the end of mining, i.e., the 1995–2010 period using ERS 1/2 and Envisat satellite radar data. Satellite radar data from European Space Agency missions are the only source of information on historical surface movements and provide spatial coverage of the entirety of the coal fields. In addition, we attempted to analyze the relationship of the ground deformations with hydrogeological changes and geological and mining data. Three distinct stages of ground movements were identified in the study. The ground motions (LOS (Line Of Sight)) determined with the PSInSAR (Persistent Scatterer Interferometry) method indicate uplift of the surface of up to +8 mm/a in the first period (until 2002). The extent and rate of this motion was congruent with the process of underground water table restoration in separate water basins associated with three neighboring coal fields. In the second period, after the stabilization of the underground water table, the surface remained active, as indicated by local subsidence (up to −5 mm/a) and uplift (up to +5 mm/a) zones. We hypothesize that this surface activity is the result of ground reaction disturbed by long-term shallow and deep mining. The third stage is characterized by gradual stabilization and decreasing deformations of the surface. The results accentuate the complexity of ground motion processes in post-mining areas, the advantages of the satellite radar technique for historical studies, and provide information for authorities responsible for new development of such areas, e.g., regarding potential flood zones caused by restoration of groundwater table in subsided areas.

scholarly journals Development and operation of a muon detection system under extremely high humidity environment for monitoring underground water table

2013 ◽  
Vol 2 (1) ◽  
pp. 29-34 ◽  
Author(s):  
H. K. M. Tanaka ◽  
A. Sannomiya
Keyword(s):  
Water Table ◽  
Detection System ◽  
Scintillation Counter ◽  
Underground Water ◽  
Water Levels ◽  
Complex Nature ◽  
Borehole Data ◽  
High Humidity Environment ◽  
Underground Water Table ◽  
Muon Detection

Abstract. In order to investigate the complex nature of landslides triggered by rainfall, dynamic muon radiography of the motion of the underground water table is planned in a drainage tunnel drilled underneath an estimated fault plane. However, the humidity inside the tunnel is almost 100%. In order to suppress moisture effects, a scintillation counter with Cockcroft–Walton photomultipler tubes (CW-MPT) was developed and tested at the observation site located in Shizuoka Prefecture, Japan. The counter was stably operated for 38 days without gain degrading. Based on the result, we constructed a muon detection system with CW-PMTs at the same site and started operation runs. In this work, the data from borehole-based water gauge measurements of the underground water levels were analyzed and discussed. It was confirmed that the comparison between muon and borehole data would be useful.

scholarly journals Development and operation of a muon detection system under extremely high humidity environment for monitoring underground water table

2012 ◽  
Vol 2 (2) ◽  
pp. 719-736 ◽  
Author(s):  
H. K. M. Tanaka ◽  
A. Sannomiya
Keyword(s):  
Water Table ◽  
Detection System ◽  
Scintillation Counter ◽  
Underground Water ◽  
Water Levels ◽  
Complex Nature ◽  
Borehole Data ◽  
High Humidity Environment ◽  
Underground Water Table ◽  
Muon Detection

Abstract. In order to investigate the complex nature of the landslides triggered by rainfall, dynamic muon radiography of the motion of the underground water table is performed in a the drainage tunnel drilled underneath an the estimated fault plane. However, the humidity inside the tunnel is almost 100%. In order to suppress the moisture effect, a scintillation counter with Cockcroft-Wwalton photomultipler tubes (CW-MPT) was developed and tested at the observation site. The counter was stably operated for 38 days without gain degrading. Based on the result, we constructed a muon detection system with CW-PMTs at the same site and started operation runs. In this work, the data from borehole-based measurement of the underground water levels were analyzed and discussed. It was confirmed that the comparison between muon and borehole data would be useful.

scholarly journals Viability Assessment in Liver Transplantation—What Is the Impact of Dynamic Organ Preservation?

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 161
Author(s):  
Rebecca Panconesi ◽  
Mauricio Flores Carvalho ◽  
Matteo Mueller ◽  
David Meierhofer ◽  
Philipp Dutkowski ◽  
...  
Keyword(s):  
Liver Function ◽  
Organ Preservation ◽  
Ex Situ ◽  
Current Status ◽  
Intensive Care Treatment ◽  
Viability Assessment ◽  
Great Opportunity ◽  
Continuous Increase ◽  
Diagnostic Time ◽  
The Impact

Based on the continuous increase of donor risk, with a majority of organs classified as marginal, quality assessment and prediction of liver function is of utmost importance. This is also caused by the notoriously lack of effective replacement of a failing liver by a device or intensive care treatment. While various parameters of liver function and injury are well-known from clinical practice, the majority of specific tests require prolonged diagnostic time and are more difficult to assess ex situ. In addition, viability assessment of procured organs needs time, because the development of the full picture of cellular injury and the initiation of repair processes depends on metabolic active tissue and reoxygenation with full blood over several hours or days. Measuring injury during cold storage preservation is therefore unlikely to predict the viability after transplantation. In contrast, dynamic organ preservation strategies offer a great opportunity to assess organs before implantation through analysis of recirculating perfusates, bile and perfused liver tissue. Accordingly, several parameters targeting hepatocyte or cholangiocyte function or metabolism have been recently suggested as potential viability tests before organ transplantation. We summarize here a current status of respective machine perfusion tests, and report their clinical relevance.

scholarly journals Cross-evaluation of social mining for classification of depressed online personas

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Alina Trifan ◽  
José Luis Oliveira
Keyword(s):  
Transfer Learning ◽  
Early Stage ◽  
Post Partum ◽  
Evaluation Study ◽  
Continuous Increase ◽  
Digital Phenotyping ◽  
Public Datasets ◽  
The Impact ◽  
Social Mining

Abstract With the continuous increase in the use of social networks, social mining is steadily becoming a powerful component of digital phenotyping. In this paper we explore social mining for the classification of self-diagnosed depressed users of Reddit as social network. We conduct a cross evaluation study based on two public datasets in order to understand the impact of transfer learning when the data source is virtually the same. We further complement these results with an experiment of transfer learning in post-partum depression classification, using a corpus we have collected for the matter. Our findings show that transfer learning in social mining might still be at an early stage in computational research and we thoroughly discuss its implications.

scholarly journals Monoclinic and Orthorhombic NaMnO2 for Secondary Batteries: A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1230
Author(s):  
Jessica Manzi ◽  
Annalisa Paolone ◽  
Oriele Palumbo ◽  
Domenico Corona ◽  
Arianna Massaro ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Reversible Capacity ◽  
Beta Phase ◽  
X Ray Diffraction ◽  
Positive Electrodes ◽  
Detailed Structural Analysis ◽  
Physico Chemical ◽  
Sodium Batteries ◽  
The Impact ◽  
First Time

In this manuscript, we report a detailed physico-chemical comparison between the α- and β-polymorphs of the NaMnO2 compound, a promising material for application in positive electrodes for secondary aprotic sodium batteries. In particular, the structure and vibrational properties, as well as electrochemical performance in sodium batteries, are compared to highlight differences and similarities. We exploit both laboratory techniques (Raman spectroscopy, electrochemical methods) and synchrotron radiation experiments (Fast-Fourier Transform Infrared spectroscopy, and X-ray diffraction). Notably the vibrational spectra of these phases are here reported for the first time in the literature as well as the detailed structural analysis from diffraction data. DFT+U calculations predict both phases to have similar electronic features, with structural parameters consistent with the experimental counterparts. The experimental evidence of antisite defects in the beta-phase between sodium and manganese ions is noticeable. Both polymorphs have been also tested in aprotic batteries by comparing the impact of different liquid electrolytes on the ability to de-intercalated/intercalate sodium ions. Overall, the monoclinic α-NaMnO2 shows larger reversible capacity exceeding 175 mAhg−1 at 10 mAg−1.

scholarly journals Structural Reliability Sensitivities under Nonstationary Random Vibrations

2013 ◽  
Vol 2013 ◽  
pp. 1-21 ◽  
Author(s):  
Rita Greco ◽  
Francesco Trentadue
Keyword(s):  
Structural Reliability ◽  
Structural Parameters ◽  
Time Integration ◽  
Structural Response ◽  
Integration Scheme ◽  
Structural Systems ◽  
Frame Building ◽  
Time Integration Scheme ◽  
Noise Input ◽  
The Time Domain

Response sensitivity evaluation is an important element in reliability evaluation and design optimization of structural systems. It has been widely studied under static and dynamic forcing conditions with deterministic input data. In this paper, structural response and reliability sensitivities are determined by means of the time domain covariance analysis in both classically and nonclassically damped linear structural systems. A time integration scheme is proposed for covariance sensitivity. A modulated, filtered, white noise input process is adopted to model the stochastic nonstationary loads. The method allows for the evaluation of sensitivity statistics of different quantities of dynamic response with respect to structural parameters. Finally, numerical examples are presented regarding a multistorey shear frame building.

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