Appearance Of Leak Research Articles

Detection of emergent leaks using machine learning approaches

Abstract In this work, we focus on the detection of leaks occurring in district metered areas (DMAs). Those leaks are observable as a number of time-related deviations from zone patterns over days or weeks. While they are detectable given enough time, due to the huge cost of water loss resulting from an undetected leak, the main challenge is to find them as soon as possible, when the deviation from the zone pattern is small. Using our collected observational data, we investigate the appearance of leaks and discuss the performance of several machine learning (ML) anomaly detectors in detecting them. We test a diverse set of six anomaly detectors, each based on a different ML algorithm, on nine scenarios containing leaks and anomalies of various kinds. The proposed approach is very effective at quickly (within hours) identifying the presence of a leak, with a limited number of false positives.

Sidcof - inspection and surveillance of penstocks

The SIDCOF (Innovative Forced Pipe Diagnostic System) project, carried out within the framework of FUI 22, aims to develop innovative NDT methods and tools in three batches allowing:  In situ monitoring of penstocks  A robotic inspection of the inside of the pipes to avoid human intervention in a complex environment  A software platform to process data and help the operator to make decisions This paper will focus on the 1st batch. The work has enabled the development of sensor networks permanently installed directly on the pipe for monitoring installations and monitoring in real time the damage caused by rockfall, landslides and water leaks. Two dedicated systems have been developed and validated under real operating conditions. The first is based on a network of connected autonomous extensometers, each module of which operates wirelessly and is energy independent. It is able to follow the deformations of pipes in risk areas following landslides. This tool greatly simplifies the implementation of sensors and automatically routes the data produced by these sensors to the cloud. A totally IIOT product. The second uses a network of acoustic emission sensors to detect and locate (with an accuracy of the order of a few meters) in real time falling rocks, and the appearance of leaks on the pipe. The tool developed is a dedicated multi-channel system for on-board electronics and processing. The data processed is transferred automatically to the client cloud via the 4G network. The SIDCOF project is led by SETEC with CETIM, SOREA, ETE and Sub C Marine as partners, funded by BPI France, TENERRDIS, INDURA, Région Occitanie, Région Auvergne Rhône Alpes.

Calculation Method to Determine the Zone of Underground Damage in Water Supply System Pipelines

The application of water conservation and leakage prevention at all stages of water delivery to the consumer can provide the rational and efficient use of water resources. The long length of heating and water supply networks, their high degree of wear and tear lead to the appearance of leaks. The paper describes research results on developing the calculating method for detecting underground damage zones in the water supply system pipeline. The basis for this study is the main difference between the regulated water intake for the needs of the water user and the uncontrolled loss of water from a damaged pipeline. The water user takes water from the water supply system in accordance with the designed parameters, and such a water intake will not cause unusual changes in the water pressure in the pipeline. The volume of water lost through pipeline damage will always be proportional to the sharp water pressure change in the pipeline. We developed the mathematical model to substantiate the detecting method of the pipeline damage zone. The model considers the operational characteristics of pipelines to the full extend: head and water flow, the degree of deterioration of water conduit, the geodetic position of water intake points. The mathematical model, confirmed earlier by dozens of independent experiments, made it possible to replace expensive hydraulic experiments and prove the possibility of using the developed method of detecting hidden damages of water conduits by extrapolating the measured piezometric heads. The proposed software system for calculating the underground pipeline damage zone in water supply systems makes it possible to determine the pipeline damage hidden zones based on solving the hydraulic problem for a linear pipeline and studying hydraulic processes. We can use the created optimization model as a proven analog of a physical hydraulic stand in hydraulic studies in the simulation mode.

SISTEMA DE IMPERMEABILIZAÇÃO: UMA ANÁLISE SOBRE OS PROCEDIMENTOS DE EXECUÇÃO

The damage generated in buildings due to the presence of water, resulting from the absence of the waterproofing system, reduces the life of the construction, causing pathologies that cause discomfort to users, loss of equipment, and financial losses. Based on this conjecture, this article presents a brief study about the waterproofing system and pathologies caused by moisture. It then assesses the procedures for implementing the waterproofing system in a vertical residential condominium in its construction phase. To this end, the monitoring of the execution of these activities was carried out, using a checklist, formulated through the manufacturer's instructions and NBR 9575 (2010). Then, all the procedures found that could generate future pathologies were specified, in addition to showing why these practices can weaken the waterproofing system. Next, the number of procedures in disagreement was analyzed as a percentage according to the checklist. At the end, the importance of correct execution to ensure the efficiency of the waterproofing system was observed. Because, it was found that all the procedures recommended by the manufacturer and NBR 9574:2008 were not complied with. Overall, only 55% of procedures were performed properly. The following pathologies can be caused by the appearance of leaks, stains on the lining, mold, mold and blistering of the wall and lining, rust of the plaster lining fixing wire, and efflorescence on the ground floor, cryptoflorescence.

Insights into the treatment of postsleeve gastrectomy leak: analysis of the results of 105 cases on a national register.

Many options have been put forward to treat staple line leaks after sleeve gastrectomy (SG) but no clear consensus has emerged concerning a management algorithm. Aiming to establish a pattern to tailor treatment, the Spanish Society of Obesity Surgery (SECO) and the Obesity Section of the Spanish Association of Surgeons (AEC) set up a national register to record treatment of leaks after SG. Multiple hospital centers, Spain. Between September 2016 and December 2017, cases were entered into an online database. Results were assessed according to the number and type of therapeutic procedures. One hundred and five patients from 27 centers were diagnosed with postSG leak. The mean age was 44 years, and 77 (73%) were women. Mean body mass index (BMI) was 47 kg/m2. Mortality was 7%. The first treatment was effective in 50% of cases with no significant differences between nonoperative management and surgery. We found no significant correlations between appearance of leak, type of treatment (nonoperative management or surgery), and treatment effectiveness. An endoscopic stent was the first nonoperative option in 30% of cases and second option in 50% of cases, with effectiveness of 61% and 50%, respectively. In patients requiring a third treatment option (n = 25), surgery was more effective than nonoperative treatment (75% versus 8%) and the incidence of complications secondary to endoscopic stent placement was high (71%). The choice of postSG leak treatment depends on the patient's clinical condition and the site of the leak. Healing may be slow (>2 months) and may require several interventions using different approaches such as nonoperative treatment, endoscopic stents, or surgery. The effectiveness of endoscopic options decreases and the effectiveness of complex resective or derivative surgery increases with leak duration and the number of treatments required.

Influence of kinesthetic motor imagery and effector specificity on the long-latency stretch response.

The long-latency "reflexive" response (LLR) following an upper limb mechanical perturbation is generated by neural circuitry shared with voluntary control. This feedback response supports many task-dependent behaviors and permits the expression of goal-directed corrections at latencies shorter than voluntary reaction time. An extensive body of literature has demonstrated that the LLR shows flexibility akin to voluntary control, but it has not yet been tested whether instruction-dependent LLR changes can also occur in the absence of an overt voluntary response. The present study used kinesthetic motor imagery (experiment 1) and instructed participants to execute movement with the unperturbed contralateral limb (experiment 2) to explore the relationship between the overt production of a voluntary response and LLR facilitation. Activity in stretched right wrist flexors were compared with standard "do not-intervene" and "compensate" conditions. Our findings revealed that on ~40% of imagery and ~50% of contralateral trials, a response occurred during the voluntary epoch in the stretched right wrist flexors. On these "leaked" trials, the early portion of the LLR (R2) was facilitated and displayed a similar increase to compensate trials. The latter half of the LLR (R3) showed further modulation, mirroring the patterns of voluntary epoch activity. By contrast, the LLR on "non-leaked" imagery and contralateral trials did not modulate. We suggest that even though a hastened voluntary response cannot account for all instruction-dependent LLR modulation, the overt execution of a response during the voluntary epoch in the same muscle(s) as the LLR is a prerequisite for instruction-dependent facilitation of this feedback response.NEW & NOTEWORTHY Using motor imagery and contralateral responses, we provide novel evidence that facilitation of the long-latency reflex (LLR) requires the execution of a response during the voluntary epoch. A high proportion of overt response "leaks" were found where the mentally simulated or mirrored response appeared in stretched muscle. The first half of the LLR was categorically sensitive to the appearance of leaks, whereas the latter half displayed characteristics closely resembling activity in the ensuing voluntary period.

Classification and Management of Leaks after Gastric Bypass for Patients with Morbid Obesity: A Prospective Study of 60 Patients

The most important and frequent major complication after gastric bypass is the appearance of a leak, which can result in death of a patient. The purpose of this prospective study was to determine the incidence of a postoperative leak, to propose a classification and to evaluate the results of conservative or surgical treatment. All patients submitted to gastric bypass either laparotomic or laparoscopic were included in a prospective protocol. In all radiological evaluation at 4(th) day after surgery was performed. The presence of a leak was evaluated according to the day of appearance, its location and its severity. Results of medical or surgical treatment were analyzed. From 1764 patients submitted to Roux-en-Y gastric bypass, 60 had a postoperative leak (3.4%). This leak appeared early after surgery (before 4 days) in 20%. It was a localized subclinical leak in 20% and clinical - septic in 80%. There were 7 possible anatomic location of a leak, being the gastrojejunal anastomosis the most frequent location (53%) followed by gastric pouch. The highest mortality was associated to the jejuno-jejunal anastomosis. Conservative treatment was employed in near 65% of the patients: The mean time of closure of a leak was 34 days. The appearance of a postoperative leak is a major and serious complication. It can be classified according to the day of appearance, its severity and its location. Conservative or surgical treatment can be employed properly if these 3 parameters are carefully evaluated.

Laparoscopic Heller myotomy and fundoplication: findings and predictive value of early postoperative radiographic studies.

We describe the findings on esophagography, the frequency and appearance of leaks after laparoscopic Heller myotomy and fundoplication, and the utility of early postoperative studies for predicting clinical outcome. Our study group consisted of 40 patients who underwent laparoscopic Heller myotomy and fundoplication in whom radiographic studies were performed during the early postoperative period. The radiographic reports and images were reviewed to determine the esophageal diameter, visualization or nonvisualization of the wrap, and the presence or absence of a leak. The esophageal diameter subsequently was correlated with the clinical findings to determine whether this was a useful parameter for predicting clinical outcome. Two patients (5%) had small, sealed-off leaks on radiographic studies, and four (10%) had pseudo-leaks resulting from trapping of contrast material alongside the fundoplication wrap. Twelve (60%) of 20 patients with a dilated esophagus had esophageal symptoms on short-term follow-up versus three (15%) of 20 with a normal-caliber esophagus (p = 0.008), and five (56%) of nine patients with a dilated esophagus had symptoms on long-term follow-up versus six (43%) of 14 with a normal-caliber esophagus (p = 0.68). Radiographic studies are useful for showing leaks after laparoscopic Heller myotomy and fundoplication, but radiologists should differentiate true leaks from trapping of contrast material alongside the fundoplication wrap. The caliber of the esophagus on early postoperative studies is also a useful parameter for predicting short-term clinical outcome in these patients.

Risk Factors for Abdominal Wall Complications in Peritoneal Dialysis Patients

Patients treated with peritoneal dialysis (PD) have increased intra-abdominal pressure and a high prevalence of abdominal wall complications. The purpose of this study was to determine the incidence of hernias and peritoneal leaks in our PD patients and to investigate their potential risk factors. We studied 142 unselected patients treated with PD during the past 5 years, including those that were already on PD and those that started PD during this period. Mean age was 54 years and mean follow-up on PD was 39 months. 72 patients had been treated with only continuous ambulatory PD (CAPD), 8 with automated PD (APD), and 62 with both modalities. 53 patients (37%) developed hernia and/or leak. A total of 39 hernias and 63 leaks were registered. The overall rates were 0.08 hernias/patient/year and 0.13 leaks/patient/year. 17 patients had both abdominal complications. Hernia was most frequently located in the umbilical region, and the most frequent site of leakage was the pericatheter area. Both complications appeared more frequently during the CAPD period (87% of hernias, 81% of leaks). The rate of hernias was higher in patients treated only with CAPD than in those that used only cyclers [0.08 vs 0.01 hernias/patient/year, not significant (NS)]. No patient treated only with APD had peritoneal leak; 25% (18/72) of patients treated with CAPD developed this complication (p = 0.18, NS). Dialysate exchange volumes ranged from 2000 to 2800 mL. 25 (66%) patients required surgical repair of the hernia, with recurrence in 7 patients (28%). 27 (84%) patients with leaks were initially treated with transitory temporary transfer to hemodialysis, low volume APD, or intermittent PD for 4 weeks. The leak recurred in half of the cases and surgical repair was necessary in 12 cases. The development of hernia and/or leak did not correlate with gender, diabetes, duration of follow-up, type of PD, history of abdominal surgery, or with the largest peritoneal exchange volume used. Polycystic kidney disease was the only factor associated with higher rate of hernias (p = 0.005), whereas increased age (p = 0.04) and higher body mass index (p = 0.03) were significantly associated with the appearance of leaks. Abdominal hernias and peritoneal leaks are very frequent in the PD population. Advanced age, polycystic kidney disease, and high body mass index are independent risk factors for their development. Automated PD with low daytime fill volume should be considered in all patients at risk for hernias and/or leaks.

Analysis of the fluctuations of the average monthly activity at a nuclear power plant with an RBMK-1000 reactor

The results of an analysis of the fluctuations of the relative activity of gaseous (inert) and the specific activity of volatile (iodine) fission products in the technological medium of the power-generating units of the Kursk and Smolensk nuclear power plants in 1996 and 1997 are presented. It is shown that these quantities behave in time as fluctuation bursts against a quasistationary background. Using a large set of statistical data, it is shown that this character of the activity is a consequence of two processes: the appearance of leaks in the fuel elements and the unloading of fuel assemblies containing unsealed fuel elements. A relation, which is the same for all power-generating units, between the number of bursts per year and the number of unloaded fuel assemblies is found. The amplitude distribution functions of the bursts, indicating the existence of groups of defects in RBMK-1000 fuel elements, are obtained. The results obtained are discussed and conclusions are presented. 3 figures, 1 table, 1 reference.