Evaluation and Control of the reliability of Weld Joints in Petroleum Products Transportation Pipelines

The economic performance of petroleum products transport companies is dependent on the reliability of their equipment. Ruptures of the weld joints of petroleum products carriage pipelines have major consequences at the human, environmental and economic levels. Weld joints are potential sites of dangerous cracks. The management of reliability of weld joints in pipelines is useful to integrate the quality planning and risks throughout their life cycle and to systematically track their characteristics all along their life cycles. The use in situ of inspection results from non-destructive control techniques is an essential component of evaluation and control of reliability of pipes in their function. It requires calculation methods and tools to assist in the decision-making in support of inspection and repair campaigns. It is in this context that the present study was conducted, which is a contribution to the efforts of methodological assessment of the reliability of petroleum products transport pipelines

Effect of shape factor on structural reliability analysis of a surface cracked pipeline-parametric study

The variation of crack shape factor (a/c) during propagation has an important role on calculation of the stress intensity factor (SIF), where imprecise estimation of this latter can lead us to an inaccurate prediction of failure probabilities. For the case of external cracked surface pipeline carried oil and gas products, such estimation can results undesired fault decisions like excessive repairs action or inspection planning. In this paper, the structural integrity analysis of pipeline with semi elliptical crack on the external surface is evaluated.  Reliability calculations expressed in term of reliability index β are carried out based on Monte Carlo simulation and First Order reliability Method (FORM). The crack shape factors are varied to cover a variety of geometries from shallow to deep cracks while fatigue crack growth is assumed in depth direction. For SIF estimation, surface and deep point are considered. Results of the analysis indicate that for a constant crack depth a/t, the reliability index is strongly affected by a/c ratio and the trend is not similar in deep and surface point for different crack shapes

Characterization of fetal microchimeric immune cells in mouse maternal hearts during physiologic and pathologic pregnancies

Introduction: During pregnancy, fetal cells can be incorporated into maternal tissues (fetal microchimerism), where they can persist postpartum. Whether these fetal cells are beneficial or detrimental to maternal health is unknown. This study aimed to characterize fetal microchimeric immune cells in the maternal heart during pregnancy and postpartum, and to identify differences in these fetal microchimeric subpopulations between normal and pregnancies complicated by spontaneous preterm induced by ascending infection.Methods: A Cre reporter mouse model, which when mated with wild-type C57BL/6J females resulted in cells and tissues of progeny expressing red fluorescent protein tandem dimer Tomato (mT+), was used to detect fetal microchimeric cells. On embryonic day (E)15, 104 colony-forming units (CFU) E. coli was administered intravaginally to mimic ascending infection, with delivery on or before E18.5 considered as preterm delivery. A subset of pregnant mice was sacrificed at E16 and postpartum day 28 to harvest maternal hearts. Heart tissues were processed for immunofluorescence microscopy and high-dimensional mass cytometry by time-of-flight (CyTOF) using an antibody panel of immune cell markers. Changes in cardiac physiologic parameters were measured up to 60 days postpartum via two-dimensional echocardiography.Results: Intravaginal E. coli administration resulted in preterm delivery of live pups in 70% of the cases. mT + expressing cells were detected in maternal uterus and heart, implying that fetal cells can migrate to different maternal compartments. During ascending infection, more fetal antigen-presenting cells (APCs) and less fetal hematopoietic stem cells (HSCs) and fetal double-positive (DP) thymocytes were observed in maternal hearts at E16 compared to normal pregnancy. These HSCs were cleared while DP thymocytes persisted 28 days postpartum following an ascending infection. No significant changes in cardiac physiologic parameters were observed postpartum except a trend in lowering the ejection fraction rate in preterm delivered mothers.Conclusion: Both normal pregnancy and ascending infection revealed distinct compositions of fetal microchimeric immune cells within the maternal heart, which could potentially influence the maternal cardiac microenvironment via (1) modulation of cardiac reverse modeling processes by fetal stem cells, and (2) differential responses to recognition of fetal APCs by maternal T cells

Etude des relations entre résistance à l’amorçage de la corrosion intergranulaire et structure des joints de grains sur cuivre polycristallin

Etude des relation entre microstructure et phénomènes liés à l'initiation de la corrosion intergranulaire. notre stratégie et l’étude des surface de cuivre polycristallin par microscopie à champs proche et en ebsdREALISATION DE SERIE D4IMAGE EN UTILISANT ecstm FAIRE une etude comparative et definire le role de la microstructur

Local passivation of metals at grain boundaries : In situ scanning tunneling microscopy study on copper

REALISATION DE SERIE D4IMAGE EN UTILISANT ecstm FAIRE une etude comparative et definire le role de la microstructureEtude des relation entre microstructure et phénomènes liés à l'initiation de la corrosion intergranulaire. notre stratégie et l’étude des surface de cuivre polycristallin par microscopie à champs proche et en ebs

Analysis of predictive models of oil transportation ducts rehabilitation

The actions of the various phenomena of corrosion, mechanical constraints and others, contribute to the degradation of hydrocarbons transportation ducts. The combinations of th ese phenomena accelerate pipe ageing, and this results in the increase of the frequency of leaks interventions and pipe ruptures. The only way to struggle against the ageing of oil transportation pipelines is the rehabilitation. This will allow the re - serv icing of pipes whose resistance characteristics are degraded. One of the major difficulties, during the conception of a pipeline rehabilitation program, is the determination of the specific sections to rehabilitate. Indeed if there is any real risk not to do enough rehabilitation in the one hand, there is a risk to bad rehabilitation on the other. The decision to continue to maintain, renovate or replace some degraded sections of a pipeline is not an easy task, and requires development of forecasting models that will enable decision - makers to take the right decisions on the middle and long term. In this context, this study is devoted to analysis of problems associated with statistical exploitation of controls and repair files of aged pipes, establishing acti on plans and controlling the ageing of hydrocarbons transportation pipeline

A robust and efficient vector-based key management scheme for IoT networks

International audienc

Fiabilist and economic approaches to optimisation of the renewal of hydrocarbons transporting pipelines

Problems of hydrocarbons transporting pipelines agi ng and rehabilitation are currently a major concern for operators of such installations. Rehabilitating and insuring hydrocarbons transporting pipelines, require interventions, such as the renovation of existing lines, the replacement of some pipelines with new ones, in order to meet the growing demand of consumers and improve the supply reliability. In this context, a decision to repair or replace a section of pipe must co mbine both a technical analysis of failures and sound economic analysis of the choice of possible interventions , which is the purpose of this study, dedicated to research and policy determination of repair and replac ement of aged pipe sections, taking into account the factors mentioned above, and based on significant feedbac