scholarly journals Analyzing the Impact of Refactoring Variants on Feature Location

Author(s):  
Amine Benmerzoug ◽  
Lamia Yessad ◽  
Tewfik Ziadi
Keyword(s):  
2017 ◽  
Vol 52 (12) ◽  
pp. 63-76 ◽  
Author(s):  
Raúl Lapeña ◽  
Jaime Font ◽  
Óscar Pastor ◽  
Carlos Cetina

Author(s):  
Riski H. Adianto ◽  
Jason B. Skow ◽  
Jeffrey Sutherland

An analysis describing the benefits of an accurate in-line inspection (ILI) system performance is presented in this paper. A good ILI performance is characterized as an accurate description of the condition of an inspected pipeline. Information from a better ILI performance, as compared to a poorer one, can be used to reduce the number of required digs and/or extend the re-inspection interval without compromising the pipeline’s integrity. As a result, these parameters can be used to assess the benefits of the improved inspection performance. For this analysis, the ILI performance was represented by the depth sizing accuracy as the depth of a feature is one of the most critical parameters in assessing the pressure containment capacity at the feature location. This work utilized a sensitivity analysis in which the impact of various levels of ILI performance on a pipeline integrity program in terms of the number of required repairs for a given reliability threshold was examined. The number of required repairs associated with each inspection performance was calculated using a reliability based assessment method. This method was selected because it fully accounts for the statistical characteristic of the ILI performance. The sensitivity analysis considered two pipeline condition scenarios for two pipeline systems. The first pipeline condition scenario was characterized as having a high number of features, many of which were severe in size, while the second condition scenario consisted of fewer features that were less significant in size. The analysis was carried out for both axial stress corrosion cracking and metal loss corrosion features. The results of the analysis show that a more accurate ILI depth measurement leads to a more accurate pipeline reliability estimate, and therefore, a reduction in the number of required repairs. However, the benefit associated with continued ILI measurement accuracy improvement exhibits a diminishing trend.


Author(s):  
Dongliang Lu ◽  
Jennifer Klementis ◽  
Shahani Kariyawasam ◽  
Terry Huang ◽  
Ryan Sager

Abstract High resolution magnetic flux leakage (MFL) in-line inspection (ILI) technology has proven to be one of the most effective approaches to manage corrosion anomalies within the pipeline industry. However, due to the presence of extra metal, pipeline casings are suspected of impacting the detection and sizing accuracy of MFL systems for metal loss features when they are located under casings. A research project was carried out by TC Energy (TCE) with ROSEN to better understand the effect of pipeline casings on the performance of axially-aligned MFL ILI (MFL-A) technology. The study involved full-scale pull through testing to investigate the effects of various casing conditions and the presence of different types of casing spacers on the inspection system’s sizing and detection performance for corrosion anomalies, including the casing eccentricity, the presence of metallic and electrolytic shorting, and the presence of different types of casing spacers. The testing for various eccentricity and shorting scenarios were compared to an uncased baseline scenario. An important lesson learned by the project team through this research is the importance of identifying key factors that influence the system performance when analyzing the testing results. Failure in doing so can lead to less meaningful results: in this case, an overly conservative estimate of the sizing performance that does not discriminate appropriately where the system performed well and where the system performed worse than expected. The impact of such a broad-brushing and overly conservative estimate in the MFL system performance to pipeline integrity decisions is very significant and can result in a large number of unnecessary repairs in practice. With comprehensive data analytics, it was identified that the key factors affecting the tool performance for cased pipes are the small annulus gaps between the casing and the carrier pipe at the feature location, and the presence of certain types of spacers. For the vast majority of cases, the ILI performance under casings is comparable to the performance for uncased pipes. The results from this research suggests that with appropriate consideration of the system performance, TCE’s probabilistic ILI based corrosion management program can effectively manage corrosion anomalies within cased pipes using ILI. Additional research and testing are underway to further support this conclusion.


2013 ◽  
Vol 86 (4) ◽  
pp. 1023-1037 ◽  
Author(s):  
Marcelo de Almeida Maia ◽  
Raquel Fialho Lafetá
Keyword(s):  

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.


1962 ◽  
Vol 14 ◽  
pp. 169-257 ◽  
Author(s):  
J. Green

The term geo-sciences has been used here to include the disciplines geology, geophysics and geochemistry. However, in order to apply geophysics and geochemistry effectively one must begin with a geological model. Therefore, the science of geology should be used as the basis for lunar exploration. From an astronomical point of view, a lunar terrain heavily impacted with meteors appears the more reasonable; although from a geological standpoint, volcanism seems the more probable mechanism. A surface liberally marked with volcanic features has been advocated by such geologists as Bülow, Dana, Suess, von Wolff, Shaler, Spurr, and Kuno. In this paper, both the impact and volcanic hypotheses are considered in the application of the geo-sciences to manned lunar exploration. However, more emphasis is placed on the volcanic, or more correctly the defluidization, hypothesis to account for lunar surface features.


1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.


1997 ◽  
Vol 161 ◽  
pp. 189-195
Author(s):  
Cesare Guaita ◽  
Roberto Crippa ◽  
Federico Manzini

AbstractA large amount of CO has been detected above many SL9/Jupiter impacts. This gas was never detected before the collision. So, in our opinion, CO was released from a parent compound during the collision. We identify this compound as POM (polyoxymethylene), a formaldehyde (HCHO) polymer that, when suddenly heated, reformes monomeric HCHO. At temperatures higher than 1200°K HCHO cannot exist in molecular form and the most probable result of its decomposition is the formation of CO. At lower temperatures, HCHO can react with NH3 and/or HCN to form high UV-absorbing polymeric material. In our opinion, this kind of material has also to be taken in to account to explain the complex evolution of some SL9 impacts that we observed in CCD images taken with a blue filter.


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