1,720,971 research outputs found
Pipeline long-range inspection and monitoring by an innovative magnetic collar for magnetostrictive guided-wave systems
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Defect identification by flexural component evaluation in guided wave monitoring of pipework using a magnetostrictive sensor
No full textThe impact of the surgical technique on stenosis after laparoscopic sleeve gastrectomy: a single center study on 5235 patients
No full textBackground: Laparoscopic Sleeve Gastrectomy (LSG) has gained worldwide popularity in the last 10 years as self alone bariatric procedure. Symptomatic Stenosis (SS) is a potential severe postoperative complication and it can be divided in organic stenosis (OS) and functional stenosis (FS). The aim of this paper is to propose a modified surgical technique to prevent FS.
Methods: A retrospective review on 5235 LSG performed in Ponderas Academic Hospital between January 2011 and December 2019, searched FS in two consecutive patients groups, divided based on the modified surgical technique introduced in 2015, with fixation of the gastric tube to the pre-pancreatic fascia and stapler line's over-sewn running suture.
Results: Group A (2011-2014) included 1332 LSG, 16 SS were registered (1.2%), 7 OS and 9 FS; 3903 LSG included in group B (2015-2019), counting for 37 SS (0.95%), 27 OS and 10 FS. A statistically significant difference between the 2 groups was observed for the FS incidence (p=0.03), while it was non-significant for the OS (p=0.52) and the total number of SS (p=0.43). The endoscopic approach was used in forty-eight SS (90.5%) with a successful rate of 83%, while specifically for the FS it was 100%; only one complication was registered during endoscopic treatment, that required further surgical solution.
Conclusions: fixation of the gastric tube to the pre-pancreatic fascia and stapler line's over-sewn running suture during LSG, introduced lately, are beneficial in preventing the postoperative functional stenosis of the LSG, contributing to the improvement of the patient's quality of life
Long range guided waves characterization of defects by two port equivalents
No full textIn this paper the effectiveness of a procedure that allows the detection and characterization of defects by the analysis of two port equivalents parameters when a NDT ultrasound guided waves system is investigated. A wavelet expansion and a frequency domain representation of the input (transmitted) and output (reflected) signals have been carried out. A constant coefficient matrix behaving as a transfer function between the input and output port has been defined. The two port equivalent representation correctly simulates the complete system under a wide range of input waveforms in the actual operating condition. The effectiveness of this method to detect and characterize defects in the pipes has been investigated
IN-service inspection and on-line monitoring of inaccessible components in nuclear power plants using guided wave technology
No full textOne of the most challenging problems in the on-line monitoring of critical parameters of nuclear plants is the inspection of components that result inaccessible or difficult to reach. In this context, there is an increasing interest of the scientific community and industry for the use of Ultrasonic Guided Waves (UGW) for addressing this issue. In this work, the problem of the applicability of the UGW technique with magnetostrictive sensors to NPP structures is described, together with the outline of the related advantages as well as the main technical concerns that may arise from such applications. This methodology has been tested on experimental activities concerning high temperature applications. Results show the effectiveness of such an approach
Analysis of corrosion areas in pipelines using guided wave propagation: Numerical simulations and experimental tests
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