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Le, T. T., J. Watton e D. T. Pham. "An artificial neural network based approach to fault diagnosis and classification of fluid power systems". Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 211, n. 4 (1 giugno 1997): 307–17. http://dx.doi.org/10.1243/0959651971539830.
Testo completoAbstract (sommario):
In this paper, multilayer perceptron (MLP) type neural networks are used to detect leakages in an electrohydraulic cylinder drive. Both single-leakage and multiple-leakage type faults are investigated. The performance of MLPs is examined relating to the level of leakage flowrate and it was found that MLPs perform well for line leakages but for across-cylinder seal leakages they could only detect leakage over 1.01/min. The generalization tests on non-training leakage flowrate and working temperature are also included. A novel feature is the use of system state variables for network training, including additional terms to accelerate convergence. The approach has also made a significant contribution to multiple-fault detection, particularly for the complex three-fault case.
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Huang, Hongwei, Wen Cheng, Mingliang Zhou, Jiayao Chen e Shuai Zhao. "Towards Automated 3D Inspection of Water Leakages in Shield Tunnel Linings Using Mobile Laser Scanning Data". Sensors 20, n. 22 (21 novembre 2020): 6669. http://dx.doi.org/10.3390/s20226669.
Testo completoAbstract (sommario):
On-site manual inspection of metro tunnel leakages has been faced with the problems of low efficiency and poor accuracy. An automated, high-precision, and robust water leakage inspection method is vital to improve the manual approach. Existing approaches cannot provide the leakage location due to the lack of spatial information. Therefore, an integrated deep learning method of water leakage inspection using tunnel lining point cloud data from mobile laser scanning is presented in this paper. It is composed of three parts as follows: (1) establishment of the water leakage dataset using the acquired point clouds of tunnel linings; (2) automated leakage detection via a mask-region-based convolutional neural network; and (3) visualization and quantitative evaluation of the water leakage in 3D space via a novel triangle mesh method. The testing result reveals that the proposed method achieves automated detection and evaluation of tunnel lining water leakages in 3D space, which provides the inspectors with an intuitive overall 3D view of the detected water leakages and the leakage information (area, location, lining segments, etc.).
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Abed, Farzaneh, Francesco Berti e Stefan Lucks. "Attacking a Leakage-Resilient Authenticated Encryption Scheme without Leakage". Information & Security: An International Journal 37 (2017): 45–53. http://dx.doi.org/10.11610/isij.3704.
Testo completo
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Churojana, Anchalee, Dittapong Songsaeng, Rujimas Khumtong, Anek Suwanbundit e Guillaume Saliou. "Is Intervertebral Cement Leakage a Risk Factor for New Adjacent Vertebral Collapse?" Interventional Neuroradiology 20, n. 5 (1 gennaio 2014): 637–45. http://dx.doi.org/10.15274/inr-2014-10079.
Testo completoAbstract (sommario):
This retrospective study evaluated the relationship between intervertebral cement leakage and new adjacent vertebral fracture and describes the different characteristics of cement leakage. Increased risk of new adjacent vertebral fracture (NF) has been reported to be a complication of cement leakage in vertebroplasty. In our observation, an incidental intervertebral cement leakage may occur during vertebroplasty but is commonly asymptomatic. The study focused on osteoporotic collapse patients who had percutaneous vertebroplasty (PV) between 2005 and 2007. We divided patients into leakage and non-leakage groups and compared the incidence of NF. Leakage characteristics were divided into three types: Type I intervertebral-extradiscal leakage, Type II intradiscal leakage and Type III combined leakage. Visual analog scale for pain and the Karnofsky Performance Status at 24 h, three months, six months and one year were compared between groups and types of leakages. Among 148 PVs (102 patients) there were 30 leakages (20.27%) and 21(14.19%) NFs. The incidence of NF did not significantly differ between leakage and non-leakage groups (P<0.05). Type II was the most common type of leakage (15/30). Reduction of average pain and improvement of Karnofsky Performance Status score did not differ between groups (P<0.05). Type II had decreased pain score < type I and III at 24 h (P < 0.01), three months and six months (P < 0.1) but not at one year (P<0.10). Type II also had decreased pain score < non-leakage group only at 24 h (P<0.05). Intervertebral cement leakage is not an increased risk for NF, influenced outcomes of pain relief or improvement of physical function. Intradiscal leakage (Type II) is the most common characteristic of cement leakage and probably related to delayed pain relief.
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Haschenburger, Anja, Niklas Menke e Jan Stüve. "Sensor-based leakage detection in vacuum bagging". International Journal of Advanced Manufacturing Technology 116, n. 7-8 (9 luglio 2021): 2413–24. http://dx.doi.org/10.1007/s00170-021-07505-5.
Testo completoAbstract (sommario):
AbstractA majority of aircraft components are nowadays manufactured using autoclave processing. Essential for the quality of the component is the realization of an airtight vacuum bag on top of the component to be cured. Several ways of leakage detection methods are actually used in industrial processes. They will be dealt with in this paper. A special focus is put on a new approach using flow meters for monitoring the air flow during evacuation and curing. This approach has been successfully validated in different trials, which are presented and discussed. The main benefit of the method is that in case of a leakage, a defined limit is exceeded by the volumetric flow rate whose magnitude can be directly correlated to the leakage’s size and position. In addition, the potential of this method for the localization of leakages has been investigated and is discussed.
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Fang, QianSheng, JiXin Zhang, ChenLei Xie e YaLong Yang. "Detection of multiple leakage points in water distribution networks based on convolutional neural networks". Water Supply 19, n. 8 (29 luglio 2019): 2231–39. http://dx.doi.org/10.2166/ws.2019.105.
Testo completoAbstract (sommario):
Abstract Currently, a total of 3.6 billion people live in water-deficient areas, and the population living in water-deficient areas may reach from 4.8 to 5.7 billion by 2050. Despite that, the water distribution system (WDS) loses an average of 35% of its water resources, and the leakage rates may reach even higher values in some regions. The dual pressures of the lack of water resources and severe WDS leakage become even more problematic considering that commonly used leakage detection methods are time-consuming, labour-intensive, and can only detect single-point leakages. For multiple leakage point detection, these methods often perform poorly. To solve the problem of multiple leakage point detection, this paper presents a method for multiple leakage point detection based on a convolutional neural network (CNN). A CNN can forecast the leakages from a macro-perspective. It extracts the features of the collected historical leakage data by constructing a CNN model and predicts whether the real-time data are leakage data or not based on the learning of the features that are extracted from the historical data. The experimental results show that the detection accuracies based on 21 sensors of one, two, and three leakage points are 99.63%, 98.58% and 95.25%, respectively. After the number of sensors is reduced to eight, the leakage detection accuracies of one, two, and three leakage points are 96.43%, 94.88% and 91.56%, respectively.
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Ismayilova, H. G., Z. I. Farzalizade e L. M. Shikhiyeva. "Specification of oil leakage points based on the operation data of pipelines". Azerbaijan Oil Industry, n. 01 (15 gennaio 2022): 45–49. http://dx.doi.org/10.37474/0365-8554/2022-1-45-49.
Testo completoAbstract (sommario):
The paper deals with the analysis of negative effect of the complications in the operation of oil pipelines on environment and the analytical specification of oil leakages from the pipelines as well. An empiric expression for the approximation of oil leakage due to the failures based on the ratio of corresponding losses considering the changes of combined characteristics of pump station and pipeline before and after the leakage is offered. The paper presents the calculations on the definition of leakage points based on the data of chronicality of oil leakages from the pipelines due to the failures and the changes of operation parameters; good results have been obtained. Thus, it is possible to specify the leakage sites in the reference point by the values of rate and pressure at the moment of leakage, although in the practice it is an approximate value.
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Salgado-Barandela, Jesyca, Angel Barajas e Patricio Sanchez-Fernandez. "Geographical Distribution of Economic Impact: Sporting Events in Small Cities". International Journal of Sport Finance 18, n. 1 (febbraio 2023): 45–53. http://dx.doi.org/10.32731/ijsf/181.022023.04.
Testo completoAbstract (sommario):
There are limitations in determining the economic impact of sporting events that need to be considered. One of these is represented by first-round leakages. This work focuses on explaining first-round leakages in the economic impact of sporting events on small cities. Seeking to identify this type of leakage, we estimated the spatial distribution of the economic impact of two small-sized events organized in a town with a population of 24,248 inhabitants. The results showed a first-round leakage exceeding €300,000 and identified higher average attendee expenditure in a more developed city adjacent to the host city. Moreover, an exploratory analysis concerning the influence of leakage in final spending was performed. Finally, the elements that would increase the probability of leakage were studied. Overall, the current case study highlighted the importance of considering the existence of leakage.
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Mathye, Risimati Patrick, Miklas Scholz e Stephen Nyende-Byakika. "Optimal Pressure Management in Water Distribution Systems: Efficiency Indexes for Volumetric Cost Performance, Consumption and Linear Leakage Measurements". Water 14, n. 5 (3 marzo 2022): 805. http://dx.doi.org/10.3390/w14050805.
Testo completoAbstract (sommario):
Water is a finite resource and should be given the attention it deserves to reduce its depletion through leakages in pipe systems. The authors implemented pressure management strategies linked to fixed and variable discharge (FAVAD), the burst and background estimate (BABE), and orifice principle methodologies to analyze a two-phased comparative method for applying optimal pressure management and its efficiency indexes in measuring volumetric cost performance, consumption, leakage flowrate, linear leakage reduction, infrastructural leakage and leakage cost indices. Using time-modulated smart control pressure reducing valve (PRV) simulation processes, the authors selected Alexandra Township in Johannesburg, South Africa as a case study. The results showed a reduction in head pressure, a reduction in the system input volume (SIV) from 26,272,579 m3 to 21,915,943 m3 and a reduction in minimum night flow (MNF) from 14.01% to 12.50%. The annual estimated nodal system output (NSO) was reduced from 14,774.62 m3 to 12,787.85 m3. The monthly average linear system repairs were reduced from 246 to 177, while the efficiency index percentages of leakage frequency/km/pressure were reduced from 8.31% to 5.98%. At a unit cost of $3.18/m3, the cost of leakages declined from $4,009,315.54 to $2,862,053.10 per month, while average household consumption (AMC) reduced from 36.33 m3 to 24.56 m3. Finally, the linear reduction value R2 for the percentage of the total leakage flowrate (TLFR)/SIV declined from 0.58 to 0.5, whereas the infrastructure leakage ratio (ILI) increased from 4 to 4.3. The results fully demonstrated that optimal pressure management is an alternative way to simulate, estimate, quantify and understand where and how water is lost in a distribution system. The authors propose that the implementation of proactive leakage management and domestic background leakage repair could further assist in reducing the frequency and cost of water leakages.
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Schineis, Christian, Andrea Ullrich, Kai S. Lehmann, Christoph Holmer, Johannes C. Lauscher, Benjamin Weixler, Martin E. Kreis e Claudia Seifarth. "Microscopic inflammation in ileocecal specimen does not correspond to a higher anastomotic leakage rate after ileocecal resection in Crohn’s disease". PLOS ONE 16, n. 3 (4 marzo 2021): e0247796. http://dx.doi.org/10.1371/journal.pone.0247796.
Testo completoAbstract (sommario):
Background Patients with Crohn’s disease suffer from a higher rate of anastomotic leakages after ileocecal resection than patients without Crohn’s disease. Our hypothesis was that microscopic inflammation at the resection margins of ileocecal resections in Crohn’s disease increases the rate of anastomotic leakages. Patients and methods In a retrospective cohort study, 130 patients with Crohn’s disease that underwent ileocecal resection between 2015 and 2019, were analyzed. Anastomotic leakage was the primary outcome parameter. Inflammation at the resection margin was characterized as “inflammation at proximal resection margin”, “inflammation at distal resection margin” or “inflammation at both ends”. Results 46 patients (35.4%) showed microscopic inflammation at the resection margins. 17 patients (13.1%) developed anastomotic leakage. No difference in the rate of anastomotic leakages was found for proximally affected resection margins (no anastomotic leakage vs. anastomotic leakage: 20.3 vs. 35.3%, p = 0.17), distally affected resection margins (2.7 vs. 5.9%, p = 0.47) or inflammation at both ends (9.7 vs. 11.8%, p = 0.80). No effect on the anastomotic leakage rate was found for preoperative hemoglobin concentration (no anastomotic leakage vs. anastomotic leakage: 12.3 vs. 13.5 g/dl, p = 0.26), perioperative immunosuppressive medication (62.8 vs. 52.9%, p = 0.30), BMI (21.8 vs. 22.4 m2/kg, p = 0.82), emergency operation (21.2 vs. 11.8%, p = 0.29), laparoscopic vs. open procedure (p = 0.58), diverting ileostomy (31.9 vs. 57.1%, p = 0.35) or the level of surgical training (staff surgeon: 80.5 vs. 76.5%, p = 0.45). Conclusion Microscopic inflammation at the resection margins after ileocecal resection in Crohn’s disease is common. Histologically inflamed resection margins do not appear to affect the rate of anastomotic leakages. Our data suggest that there is no need for extensive resections or frozen section to achieve microscopically inflammation-free resection margins.
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Verstegen, Moniek, Stefan Bouwense, Frans Van Workum, Richard Ten Broek, P. D. Siersema, Maroeska Rovers e Camiel Rosman. "PS01.173: MANAGEMENT OF INTRATHORACIC AND CERVICAL ANASTOMOTIC LEAKAGE AFTER ESOPHAGECTOMY FOR ESOPHAGEAL CANCER: A SYSTEMATIC REVIEW". Diseases of the Esophagus 31, Supplement_1 (1 settembre 2018): 99. http://dx.doi.org/10.1093/dote/doy089.ps01.173.
Testo completoAbstract (sommario):
Abstract Background Anastomotic leakage affects up to 30% of patients after esophagectomy each year and leads to considerable morbidity and mortality. The aim of this study was to determine which treatment for anastomotic leakage after esophagectomy has the best clinical outcome, based on currently available literature. Methods A systematic literature search was performed in Medline, Embase and Web of Science until April 2017. All studies reporting on the treatment of anastomotic leakage following esophagectomy with gastric tube reconstruction for esophageal or cardia cancer were included. The primary outcome parameter was postoperative mortality. Methodological quality was assessed by the Newcastle-Ottawa Quality Assessment Scale. Results Nineteen retrospective cohort studies including 273 patients were identified. Methodological quality of all studies was poor to moderate. Regarding intrathoracic anastomotic leakages, mortality rates in the conservative, endoscopic stent, endoscopic drainage, endoscopic vacuum assisted closure system and surgery treatment group were 14%, 8%, 8%, 0%, and 50%, respectively. Regarding cervical anastomotic leakages, mortality rates in the conservative, endoscopic stent and endoscopic dilatation group were 8%, 29%, and 0%, respectively. Conclusion Due to small cohorts, heterogeneity between studies, and lack of data regarding leakage characteristics, no evidence supporting one treatment for anastomotic leakage after esophagectomy was found. A severity score based on leakage characteristics instead of treatment given is essential for determining the optimal treatment of anastomotic leakage. A prospective registration study could provide answers to issues as which leakage characteristics determine its severity and which treatment options have the best outcomes for a given anastomotic leakage severity. Disclosure All authors have declared no conflicts of interest.
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ZHANG, WEIQIANG, LI SU, YU ZHANG, LINFENG LI e JIANPING HU. "LOW-LEAKAGE FLIP-FLOPS BASED ON DUAL-THRESHOLD AND MULTIPLE LEAKAGE REDUCTION TECHNIQUES". Journal of Circuits, Systems and Computers 20, n. 01 (febbraio 2011): 147–62. http://dx.doi.org/10.1142/s0218126611007128.
Testo completoAbstract (sommario):
The scaling of transistor sizes has resulted in dramatic increase of leakage currents. The sub-threshold and gate leakages have now become a major contributor to total power dissipations. This paper presents two flip-flops based on dual-threshold CMOS and multiple leakage reduction techniques to reduce their leakage dissipations. In the DT-TG FF (Dual-Threshold Transmission Gate Flip-Flop), some transistors on non-critical paths use high-threshold devices to reduce their leakage currents, while the other transistors on critical paths use low-threshold devices to maintain performance. The MLRT FF (Multiple Leakage Reduction Technique Flip-Flop) uses P-type CMOS techniques, MTCMOS (Multi-Threshold CMOS) power-gating and dual-threshold technique to reduce both sub-threshold and gate leakage dissipations. Taken as an example, a practical sequential system realized with the two low-leakage flip-flops is demonstrated using a mode-5 × 5 × 5 counter. The simulation results show that the two flip-flops achieve considerable leakage reductions.
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Li, Tian, Zhi Zhen Peng, Yan Cheng Fan, Xi Ming Tang, Chen Guang Kong e Qin Yin. "Boric Acid Corrosion in the Primary System of PWRs". Advanced Materials Research 1081 (dicembre 2014): 58–62. http://dx.doi.org/10.4028/www.scientific.net/amr.1081.58.
Testo completoAbstract (sommario):
Borated water leakage could lead to boric acid corrosion of nuclear equipment, and it’s a danger to the pressurized water reactor nuclear power plants (PWRs). In this study, the principle of boric acid corrosion was studied first. Through the experiences of borated water leakages and boric acid corrosion at home and abroad, the main leakage sources in PWRs were summarized. Combining the technique features of visual inspection, the detecting principles were proposed. In the end, a protection strategy of boric acid corrosion was established including the control of borated water leakage, the detection of equipment, the treatment of leakages and the improvement of the equipment material.
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Gupta, Aditya Dinesh, e Kishore Kulat. "Leakage reduction in water distribution system using efficient pressure management techniques. Case study: Nagpur, India". Water Supply 18, n. 6 (2 febbraio 2018): 2015–27. http://dx.doi.org/10.2166/ws.2018.023.
Testo completoAbstract (sommario):
Abstract Leakages in water distribution system (WDS) are directly proportional to its operating pressure. Pressure management is becoming an important technique for reducing leakages in the water networks. This paper presents a pressure management technique for leakage reduction in north central WDS of Nagpur City, India, using variable speed pump and pressure reducing valves (PRVs). Variable speed pump is utilized for eliminating pressure deficiency during high demand and for reducing excess pressure causing leakage reduction during lower demand, by controlling the pump speed. PRVs have been used for further leakage reduction. This paper proposes a modified reference pressure algorithm for determining the location of valves in WDS. A multiobjective genetic algorithm (NSGA-II) is used to determine the optimized control value of pressure reducing valve with respect to change in demand pattern and to minimize the leakage rate in the WDS. Proposed pressure management technique leads to leakage reduction of 16.57% to 26.30% with respect to changes in demand pattern, causing daily average saving of 5.066 Ml. Minimum required pressure is maintained on every demand nodes to avoid pressure deficiency in WDS.
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Gao, Chang, Min Zong, Wen-tao Wang, Lei Xu, Da Cao e Yue-fen Zou. "Analysis of risk factors causing short-term cement leakages and long-term complications after percutaneous kyphoplasty for osteoporotic vertebral compression fractures". Acta Radiologica 59, n. 5 (7 agosto 2017): 577–85. http://dx.doi.org/10.1177/0284185117725368.
Testo completoAbstract (sommario):
Background Percutaneous kyphoplasty (PKP) is a common treatment modality for painful osteoporotic vertebral compression fractures (OVCFs). Pre- and postoperative identification of risk factors for cement leakage and follow-up complications would therefore be helpful but has not been systematically investigated. Purpose To evaluate pre- and postoperative risk factors for the occurrence of short-term cement leakages and long-term complications after PKP for OVCFs. Material and Methods A total of 283 vertebrae with PKP in 239 patients were investigated. Possible risk factors causing cement leakage and complications during follow-up periods were retrospectively assessed using multivariate analysis. Cement leakage in general, three fundamental leakage types, and complications during follow-up period were directly identified through postoperative computed tomography (CT). Results Generally, the presence of cortical disruption ( P = 0.001), large volume of cement ( P = 0.012), and low bone mineral density (BMD) ( P = 0.002) were three strong predictors for cement leakage. While the presence of intravertebral cleft and Schmorl nodes ( P = 0.045 and 0.025, respectively) were respectively identified as additional risk factors for paravertebral and intradiscal subtype of cortical (C-type) leakages. In terms of follow-up complications, occurrence of cortical leakage was a strong risk factor both for new VCFs ( P = 0.043) and for recompression ( P = 0.004). Conclusion The presence of cortical disruption, large volume of cement, and low BMD of treated level are general but strong predictors for cement leakage. The presence of intravertebral cleft and Schmorl nodes are additional risk factors for cortical leakage. During follow-up, the occurrence of C-type leakage is a strong risk factor, for both new VCFs and recompression.
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Pérez, R., V. Puig, J. Pascual, A. Peralta, E. Landeros e Ll Jordanas. "Pressure sensor distribution for leak detection in Barcelona water distribution network". Water Supply 9, n. 6 (1 dicembre 2009): 715–21. http://dx.doi.org/10.2166/ws.2009.372.
Testo completoAbstract (sommario):
This paper proposes a leakage detection method based on detecting significant discrepancies between pressure measurements and their estimations obtained from the simulation of a calibrated water distribution network model. Every sensor in the network will allow to detect a discrepancy in pressure due to leakage depending on its location. Then, a set of well distributed pressure sensors will generate a leakage signature that allows leakage localisation. This paper presents the methodology used in the Barcelona network for distributing properly the sensors for a good discrimination in the leakage localisation process. The methodology for sensor placement uses the pressure sensitivity matrix to the leakage presence. This matrix is normalised and binarised in order to be used as a leakage signature matrix using the standard model based fault diagnosis approach. Sensors may be installed in any node and leakages are simulated as a constant demand that can appear in any node too. The problem of deciding which are the best localisations for a small number of sensors in order to detect and localise leakages is an inverse problem that should be solved using optimisation. The resulting optimisation problem is of discrete nature and very huge for a real network. This type of problem is, in general, hard to solve and very time consuming. The use of GA (Genetic Algorithms) has been proved adequate according to the formulation of the signatures in the sensitivity matrix.
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Klupp, F., S. Schuler, C. Kahlert, N. Halama, C. Franz, P. Mayer, T. Schmidt e A. Ulrich. "Evaluation of the inflammatory markers CCL8, CXCL5, and LIF in patients with anastomotic leakage after colorectal cancer surgery". International Journal of Colorectal Disease 35, n. 7 (19 aprile 2020): 1221–30. http://dx.doi.org/10.1007/s00384-020-03582-2.
Testo completoAbstract (sommario):
Abstract Purpose Anastomotic leakage constitutes a dreaded complication after colorectal surgery, leading to increased morbidity and mortality as well as prolonged hospitalization. Most leakages become clinically apparent about 8 days after surgery; however, early detection is quintessential to reduce complications and to improve patients’ outcome. We therefore investigated the significance of specific protein expression profiles as putative biomarkers, indicating anastomotic leakage. Methods In this single-center prospective cohort study serum and peritoneal fluid samples—from routinely intraoperatively inserted drainages—of colorectal cancer patients were collected 3 days after colorectal resection. Twenty patients without anastomotic leakage and 18 patients with an anastomotic leakage and without other complications were included. Protein expression of seven inflammatory markers in serum and peritoneal fluid was assessed by multiplex ELISA and correlated with patients’ clinical data. Results Monocyte chemoattractant protein 2 (CCL8/MCP-2), leukemia-inhibiting factor (LIF), and epithelial-derived neutrophil-activating protein (CXCL5/ENA-78) were significantly elevated in peritoneal fluid but not in serum samples from patients subsequently developing anastomotic leakage after colorectal surgery. No expressional differences could be found between grade B and grade C anastomotic leakages. Conclusion Measurement 3 days after surgery revealed altered protein expression patterns of the inflammatory markers CCL8/MCP2, LIF, and CXCL5/ENA-78 in peritoneal fluid from patients developing anastomotic leakage after colorectal surgery. Further studies with a larger patient cohort with inclusion of different variables are needed to evaluate their potential as predictive biomarkers for anastomotic leakage.
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Hwang, Woonyong. "A Study on the Prediction of Damage Ranges by Leakages of Seaport-Stored Substances". Journal of the Korean Society of Hazard Mitigation 21, n. 2 (30 aprile 2021): 23–31. http://dx.doi.org/10.9798/kosham.2021.21.2.23.
Testo completoAbstract (sommario):
In order to check the risk of hydrogen peroxide leakage from the seaport, the leakage amount was changed from 1.0 ton to 10.0 tons, with the maximum and minimum diffusion distances per month in 2020 being subsequently calculated. A total of 82 scenarios were created to confirm the change in the diffusion distance according to the amount of leakage. The scenario was analyzed based on the distance at which the risk concentration was maintained through the ALOHA Air Dispersion Models. As indicated by the analysis, when the amount of leakage is relatively large, the temperature is also high and the wind speed is fast - resulting in the maximum spread. However, when the amount of leakage was relatively minimal, the temperature was low and the wind speed remained fast - this kept diffusion to the minimum. Concerning characteristics of fast wind speeds, the dispersion length changed based on amounts of leakages where PAC-1 contains 2.0 tons, PAC-2 contains 4.0 tons, and PAC-3 contains 5.0 tons. In addition, when the amount of leakage equaled 10.0 tons, and the wind speed was high, the dispersion length reached up to 10 kms. In light of this, it was confirmed that even adjacent administrative districts were affected. Therefore, it is necessary to establish appropriate measures to prevent damage by utilizing the diffusion distance caused by chemical leakages.
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Yu, Ming Yi. "The Research and Simulation of Intelligent Electric Leakage Detection Model for Mining Machinery". Advanced Materials Research 986-987 (luglio 2014): 1616–18. http://dx.doi.org/10.4028/www.scientific.net/amr.986-987.1616.
Testo completoAbstract (sommario):
For today’s coal mining enterprises, the mining production environment is very harsh and sometimes there are electric leakages in the automatic production equipment which cause a great impact on the stability of coal production. This paper proposes an electric leakage fault intelligent detection model. The intelligent method can fix the electric leakage faults on time which is an important prerequisite to ensure mine production stable and secure. The experimental results show that the model can effectively detect hardware failures and leakage.
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Wateya, Ali Wambi, Twaibu Semwogerere, Richard O. Awichi e Asaph Keikara Muhumuza. "Mathematical Modelling of Oil Pipeline Leakages Using Computational Fluid Dynamics - Case of BIDCO Oil Processing Refinery, Uganda." JOURNAL OF ADVANCES IN MATHEMATICS 21 (16 febbraio 2022): 25–31. http://dx.doi.org/10.24297/jam.v21i.9163.
Testo completoAbstract (sommario):
The leakage flow phenomena of a refinery oil pipe with a leakage point is numerically studied with the purpose to minimize oil leakage using Computational Fluid Dynamics (CFD) approach. Among consequences of oil pipe leakages are losses as a result of property loss (oil), cost of pipe replacement and also death due to fire or explosion. To understand the leakage phenomena, pipe characteristics at the leakage orifice are necessary. In the simulation, considering a pipe with a leak orifice of 0.002m, diameter 0.06 m and length 10 m, single phased flow was considered. The leakage through the pipe was studied based on fluid dynamics simulations using a Computational fluid dynamic tool ANSYS FLUENT software 17.2 where the Navier-Stokes were solved and for turbulence the standard k-ε was considered. Results from this study show that the leakage flow rate increases with increase in velocity inflow of the fluid. The pressure effect was also studied at the vicinity of the leak and results also show that an increase in velocity increases the pressure drop. Therefore, keeping the inflow velocity range of 0.1ms−1 to 2 ms−1 show minimal leakage rates.
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Kwon, Soonbeom, Hyeongryeol Kim, Seonyeong Choi e Hwansoo Lee. "The Improvement Method of Digital Forensic for Responding to Technology Leakage of SMEs". Korean Career, Entrepreneurship & Business Association 7, n. 1 (30 gennaio 2023): 85–101. http://dx.doi.org/10.48206/kceba.2023.7.1.85.
Testo completoAbstract (sommario):
Industrial technology leakage is increasingly becoming sophisticated, intelligent, and advanced. So, the police organized an industrial technology leakage investigation team in November 2006 and expanded the indust rial technology leakage investigation team to 17 local police agencies in 2017. Likewise, the police is trying to prevent industrial technology leakages, but it is still annually increasing. Especia lly, in 60.8% cases of technology leakages by insiders are done by using memory devices. Which makes digital forensic necessary in order to detect such incidents. However, problems such as shortage of man power, matters of procedure, and vast amount of digital evidence, delay fact-finding and damage restoration. This study introduces the company's digital forensic system designed for corporations which will help them obtaining digital evidences in a prompt and accurate way. This study suggests that institutes should regularly backup their datas so that they would have sufficient information to analyze incidents. Al so, it proposes companies to acquire consent from their insiders before incident s happen in order to have access to suspects' digital devices and forensic it in a legal way. Furthermore, we have analyzed signs of technology leakages based on privious studies and introduced lawful means for corporates to respond to technology leakage and evidence collecting to prevent from possible disputes.
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Choi, Gyeung Ho, Seong Keun Shin, Seok Choun Bae, Yong Jong Chung e Sung Bin Han. "Effects of injector leakage on liquid propane injection engine performance". Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 219, n. 4 (1 aprile 2005): 559–64. http://dx.doi.org/10.1243/095440705x11149.
Testo completoAbstract (sommario):
This study aims to provide basic technical information for research regarding starting performance improvement by using a 2.656 cm3 V6 liquid propane injection engine to study the effects of varying the liquefied petroleum gas (LPG) leakage on starting performance and to analyse the effects of such leakage on emission characteristics. To determine the LPG injection amount that corresponds to the desired LPG leakage, 1–30 l was injected to find the critical point and, since the injected fuel was detected at the intake starting from 5.5 l, starting performance comparisons of engine speed and exhaust gases were made at 0 l, 1 l, 2 l, 3 l, 4 l, 5 l, and 6 l by measuring the desired value five times and taking the average. Also, to study the effects of a small leak, the starting performance was tested while injecting 0 l, 0.2 l, 0.4 l, 0.6 l, 0.8 l, and 1 l. The major conclusions of this work are as follows: The results of determining the critical point of starting delay for LPG leakages of 1–30 l show that the critical point is 21 l and 14 cycles. For LPG leakages of 1–6 l, the starting time and unburned hydrocarbon (HC) increases with increasing LPG leakage. At LPG leakage of 0.2 l, the starting time is much faster at 1 cycle, but unburned HC increases with increasing LPG leakage.
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Huang, Shou Qing, Shuang Fu Suo, Kai Bing Du, Yong Jian Li e Yu Ming Wang. "Study on a Type of Low-Leakage Brush Seal Porous Media Model". Applied Mechanics and Materials 312 (febbraio 2013): 345–49. http://dx.doi.org/10.4028/www.scientific.net/amm.312.345.
Testo completoAbstract (sommario):
Computation Fluid Dynamics (CFD) has been employed to calculate the pressure, flow distributions and leakage of brush seal by using Reynolds-Averaged-Navier-Stokes (RANS) method and two-dimensional axisymmetric anisotropic porous medium model. The leakage in brush seal with radial clearance has a marked increase compared with contact brush seal. The leakages of brush seal with different radial clearances have been investigated comparing contact brush seal. A type ofretaining ring structure has been employedto reduce the leakage on radial clearance condition. Also the disturbance effect of retaining ring on bristle pack has been studied.
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Gupta, Aditya Dinesh, Neeraj Bokde, Dushyat Marathe e Kishore Kulat. "Optimization techniques for leakage management in urban water distribution networks". Water Supply 17, n. 6 (17 aprile 2017): 1638–52. http://dx.doi.org/10.2166/ws.2017.064.
Testo completoAbstract (sommario):
Abstract Reduction of leakages in water distribution systems (WDSs) is one of the major concerns for water industries. This paper presents a leakage reduction technique using pressure management by optimizing the water level in storage tanks, along with optimized control and localization of pressure-reducing valves (PRVs) in WDSs. A new mathematical tank and pump simulation algorithm is presented for controlling pressure in WDSs, by optimizing the water storage level in the tank depending upon the demand variations. The tank is used as a decision variable for the leakage reduction model. A modified reference pressure algorithm is introduced for improving PRV localization. A multiobjective genetic algorithm (NSGA-II) is used to find the optimized operational control setting of the PRV for leakage minimization. The proposed algorithm leads to a leakage reduction of 26.51% in Anytown WDS and 20.81% in a modified benchmark WDS. This technique leads to an appreciable reduction in leakage rate, with fewer PRVs required, taking into account constraints such as maintaining a lower hydraulic failure index (<0.01), emergency storage, etc. It can be concluded that the proposed novel leakage reduction technique provides a more cost effective and efficient solution for leakage control.
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Boniface, Adoyi, A. Y. Nasir e A. M. Hassan. "Arduino based gas leakage and temperature monitoring and control system". International Journal of Informatics and Communication Technology (IJ-ICT) 9, n. 3 (1 dicembre 2020): 171. http://dx.doi.org/10.11591/ijict.v9i3.pp171-178.
Testo completoAbstract (sommario):
<span lang="EN-US">Gas leakage is a major problem with industrial sectors, residential premises and gas powered vehicles like CNG (Compressed Natural Gas) buses etc. One of the preventive methods to stop accidents associated with the gas leakage is to install a gas leakage detection device at vulnerable places. The aim of this project is to develop such a device that can automatically detect and control gas leakages and also monitor temperature in vulnerable areas. The system detects the leakage of the LPG (Liquefied Petroleum Gas) using a gas sensor and then also monitors the temperature using a temperature sensor. When the LPG concentration in the air exceeds a certain level, the gas sensor senses the gas leakage and the output of the sensor goes LOW, the system then opens the exit windows, and then uses the GSM to alert the person about the gas leakage via SMS. Also, when the temperature of the environment exceeds a certain limit, it then turns ON the LED (indicator) and make an alarm through the buzzer. An LCD (16x2) displays the current temperature and gas leakage status in degree Celsius and PPM respectively.</span>
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Hou e Zhu. "An EKF-Based Method and Experimental Study for Small Leakage Detection and Location in Natural Gas Pipelines". Applied Sciences 9, n. 15 (5 agosto 2019): 3193. http://dx.doi.org/10.3390/app9153193.
Testo completoAbstract (sommario):
Small leaks in natural gas pipelines are hard to detect, and there are few studies on this problem in the literature. In this paper, a method based on the extended Kalman filter (EKF) is proposed to detect and locate small leaks in natural gas pipelines. First, the method of a characteristic line is used to establish a discrete model of transient pipeline flow. At the same time, according to the basic idea of EKF, a leakage rate is distributed to each segment of the discrete model to obtain a model with virtual multi-point leakage. As such, the virtual leakage rate becomes a component of the state variables in the model. Secondly, system noise and measurement noise are considered, and the optimal hydraulic factors such as leakage rate are estimated using EKF. Finally, by using the idea of an equivalent pipeline, the actual leakage rate is calculated and the location of leakage on the pipeline is assessed. Simulation and experimental results show that this method can consistently predict the leakage rate and location and is sensitive to small leakages in a natural gas pipeline.
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Shi, Xin, Yi Cao, Chuanxin Rong, Gangjian An, Houliang Wang e Linzhao Cui. "Influence of Pipeline Leakage on the Ground Settlement around the Tunnel during Shield Tunneling". Sustainability 14, n. 24 (14 dicembre 2022): 16802. http://dx.doi.org/10.3390/su142416802.
Testo completoAbstract (sommario):
Shield tunneling is widely used in urban subway tunnel construction. Old urban underground pipelines generally have small leakages that are difficult to find. The water leakage significantly reduces the stability of the stratum, posing a threat to the safety of tunnel shield construction. Therefore, this study established 2D and 3D calculation models for analyzing the law of the leakage diffusion in the ground under water pressure, and the influences of the pipeline leakage range and leakage length on the changes in ground settlement during shield tunneling. The 2D model calculation results show that seepage water mainly diffuses vertically under gravity. As the pipeline leakage gradually reaches a predetermined depth, the simulation results tend to be consistent with the test results. The 3D model is more accurate than the theoretical solution in predicting the ground settlement because it can consider the influences of repeated disturbances in twin tunnel shield construction. The maximum ground surface settlement increases with the extent of the leakage length and leakage range, and the range is the main factor determining the settlement. At the interior of the ground, the seepage water has a greater impact on areas with strong disturbances and large soil losses.
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Parrilla, Claudio, Ylenia Longobardi, Jacopo Galli, Mario Rigante, Gaetano Paludetti, Francesco Bussu e Emanuele Scarano. "Periprosthetic Leakage in Tracheoesophageal Prosthesis: Proposal of a Standardized Therapeutic Algorithm". Otolaryngology–Head and Neck Surgery 165, n. 3 (5 gennaio 2021): 446–54. http://dx.doi.org/10.1177/0194599820983343.
Testo completoAbstract (sommario):
Objective Periprosthetic leakage represents the most demanding long-term complication in the voice prosthesis rehabilitation. The aim of this article is to discuss the various causes of periprosthetic leakage and to propose a systematic management algorithm. Study Design Retrospective cohort study. Setting Otolaryngology clinic of the University Polyclinic A. Gemelli–IRCCS Foundation. Methods The study included 115 patients with voice prosthesis who were treated from December 2014 to December 2019. All patients who experienced periprosthetic leakage were treated with the same step-by-step therapeutic approach until it was successful. Incidence, management, and success rate of every attempt are analyzed and discussed. Results Periprosthetic leakage was reported 330 times by 82 patients in 1374 clinic accesses. Radiotherapy, timing of tracheoesophageal puncture, and type of total laryngectomy (primary or salvage) did not influence the incidence of periprosthetic leakage. Salvage total laryngectomy increases the risk of more clinically relevant leakages. Conclusion By using a systematic algorithm with a step-by-step standardized approach, periprosthetic leakage management could become a less treacherous issue.
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Wong, Wai Peng, Hwee Chin Tan, Kim Hua Tan e Ming-Lang Tseng. "Human factors in information leakage: mitigation strategies for information sharing integrity". Industrial Management & Data Systems 119, n. 6 (8 luglio 2019): 1242–67. http://dx.doi.org/10.1108/imds-12-2018-0546.
Testo completoAbstract (sommario):
Purpose The purpose of this paper is to explore the human factors triggering information leakage and investigate how companies mitigate insider threat for information sharing integrity. Design/methodology/approach The methodology employed is multiple case studies approach with in-depth interviews with five multinational enterprises (MNEs)/multinational corporations (MNCs). Findings The findings reveal that information leakage can be approached with human governance mechanism such as organizational ethical climate and information security culture. Besides, higher frequency of leakages negatively affects information sharing integrity. Moreover, this paper also contributes to a research framework which could be a guide to overcome information leakage issue in information sharing. Research limitations/implications The current study involved MNCs/MNEs operating in Malaysia, while companies in other countries may have different ethical climate and information sharing culture. Thus, for future research, it will be good to replicate the study in a larger geographic region to verify the findings and insights of this research. Practical implications This research contributes to the industry and business that are striving toward solving the mounting problem of information leakage by raising awareness of human factors and to take appropriate mitigating governance strategies to pre-empt information leakage. This paper also contributes to a novel theoretical model that characterizes the iniquities of humans in sharing information, and suggests measures which could be a guide to avert disruptive leakages. Originality/value This paper is likely an unprecedented research in molding human governance in the domain of information sharing and its Achilles’ heel which is information leakage.
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Gupta, A., N. Bokde, D. Marathe e K. Kulat. "Leakage Reduction in Water Distribution Systems with Efficient Placement and Control of Pressure Reducing Valves Using Soft Computing Techniques". Engineering, Technology & Applied Science Research 7, n. 2 (24 aprile 2017): 1528–34. http://dx.doi.org/10.48084/etasr.1032.
Testo completoAbstract (sommario):
Reduction of leakages in a water distribution system (WDS) is one of the major concerns of water industries. Leakages depend on pressure, hence installing pressure reducing valves (PRVs) in the water network is a successful techniques for reducing leakages. Determining the number of valves, their locations, and optimal control setting are the challenges faced. This paper presents a new algorithm-based rule for determining the location of valves in a WDS having a variable demand pattern, which results in more favorable optimization of PRV localization than that caused by previous techniques. A multiobjective genetic algorithm (NSGA-II) was used to determine the optimized control value of PRVs and to minimize the leakage rate in the WDS. Minimum required pressure was maintained at all nodes to avoid pressure deficiency at any node. Proposed methodology is applied in a benchmark WDS and after using PRVs, the average leakage rate was reduced by 6.05 l/s (20.64%), which is more favorable than the rate obtained with the existing techniques used for leakage control in the WDS. Compared with earlier studies, a lower number of PRVs was required for optimization, thus the proposed algorithm tends to provide a more cost-effective solution. In conclusion, the proposed algorithm leads to more favorable optimized localization and control of PRV with improved leakage reduction rate.
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Palm, Hans-Georg, Patricia Lang, Madlen Haentzsch, Benedikt Friemert, Carsten Hackenbroch e Hans-Joachim Riesner. "Diagnostic Accuracy of Fluoroscopy, Radiography, and Computed Tomography in Detecting Cement Leakage in Kyphoplasty". Journal of Neurological Surgery Part A: Central European Neurosurgery 79, n. 06 (7 maggio 2018): 502–10. http://dx.doi.org/10.1055/s-0038-1641734.
Testo completoAbstract (sommario):
Purpose Cement leakage is a typical complication of kyphoplasty for vertebral fractures. It is unclear if cement application intraoperatively can be improved by using other techniques of visualization and which kind of postoperative imaging should be recommended to detect cement extravasation accurately. Objective To compare the rates of cement leakage detected by intraoperative fluoroscopy, postoperative radiography, and postoperative computed tomography (CT) in a retrospective study. Patients and Methods The study included 78 patients (60 women and 18 men; 115 vertebral bodies) who were treated with two kinds of kyphoplasty. The patients underwent intraoperative fluoroscopy and postoperative radiography and CT. After surgery, the images were evaluated to compare cement leakage rates and locations in the three visualization techniques. Leakage locations were described as epidural, intradiskal, extravertebral, or intravascular. Results Compared with CT, intraoperative fluoroscopy regularly detected intradiskal leakage (75%) but had a considerably lower sensitivity for visualizing epidural (21%), extravertebral (31%), and intravascular (51%) cement leakages. A comparison of radiography and CT showed that radiography had a high sensitivity for detecting intradiskal (82%) and intravascular (70%) cement extrusions but a lower sensitivity in identifying epidural (42%) and extravertebral (50%) leaks. Therefore, the CT scan overall was best in detecting location and accuracy. Conclusion CT detected more cement leaks than any of the other investigated techniques, especially epidural, extravertebral, and intravascular cement leakages. To achieve the best accuracy, only CT provides complete information.
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Georgy, Bassem. "Comparison Between Radiofrequency Targeted Vertebral Augmentation and Balloon Kyphoplasty in the Treatment of Vertebral Compression Fractures: Addressing Factors that Affect Cement Extravasation and Distribution". Pain Physician 5;16, n. 5;9 (14 settembre 2013): E513—E518. http://dx.doi.org/10.36076/ppj.2013/16/e513.
Testo completoAbstract (sommario):
Background: Both vertebroplasty and balloon kyphoplasty have been described for treatment of vertebral compression fractures. Vertebroplasty is known for its high leakage rate compared with balloon kyphoplasty. In vitro studies have shown that high-viscosity cements significantly decrease the incidence of cement leakage and increase the predictability of cement fill in cancellous bonelike substrates compared with low-viscosity cements. Objective: This study compares the incidence and pattern of cement leakage in cases treated with standard balloon kyphoplasty (BKP) and a novel vertebral augmentation procedure, radiofrequency targeted vertebral augmentation (RF-TVA). Study Design: Retrospective evaluation of postoperative radiographs. Setting: Single center inpatient and outpatient population. Methods: Two methods of vertebral augmentation were utilized. Conventional bipedicular BKP and RF-TVA, a novel unipedicular technique which uses a navigational osteotome to create targeted, bone sparing cavities and RF energy to deliver an ultra-high viscosity cement at a consistent rate via a remote controlled, automated hydraulic delivery system. Postoperative radiographs of patients treated with the 2 techniques were critically analyzed for the incidence and location of cement leakage. Eighty consecutive patients with 106 treated levels were included. Thirty-five patients with 49 levels in the BKP and 45 patients with 57 levels in RF-TVA group were evaluated. Results: Leakages less than 1-2 mm were not reported since they may not represent any clinical significance. In the BKP group, 6 leakages (12%) were reported (3 discal, 2 venous, one paravaertebral, and no epidural). In the RF-TVA group, a total of 3 leakages (5%) were reported, (one discal, 2 venous, no paravaertebral or epidural). Using contingency analysis for leakage per level, there was a statistical difference for leakage between RF-TVA and standard BKP, P < 0.01. Limitations: Retrospective study, single center. Conclusions: The RF-TVA technique may provide an approximately 50% reduction in leakage rate when compared to standard BKP. This may be related to the combination of controlled delivery of radiofrequency activated (high viscosity) cement at a fixed, low rate of delivery into sitespecific channels created using a navigational osteotome. Additionally, based on the unipedicular access and remotely controlled cement delivery RF-TVA may decrease procedural invasiveness and physician radiation exposure, respectively. Institutional Review: This study was approved by the Institutional Review Board. Key words: Balloon kyphoplasty, radiofrequency targeted vertebral augmentation, compression fractures, cement leakage
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Kim, Jae Hun. "Epidural Blood Patch for the Treatment of Spontaneous and Iatrogenic Orthostatic Headache". Pain Physician 8;19, n. 8;11 (14 novembre 2016): E1115—E1122. http://dx.doi.org/10.36076/ppj/2016.19.e1115.
Testo completoAbstract (sommario):
Background: The cerebrospinal fluid (CSF) leakage could be happened spontaneously or related to the procedures such as spinal anesthesia, epidural anesthesia, CSF tapping, intrathecal chemotherapy or other spinal procedures. The leakage of CSF leads to intracranial hypotension of which distinguishing clinical feature is orthostatic headache. The epidural blood patch is a goldstandard treatment for intracranial hypotension-related orthostatic headaches. Objective: We conducted this study to compare the efficacy and number of epidural blood patches for spontaneous and iatrogenic orthostatic headaches. Study Design: Retrospective study. Setting: University hospital inpatient and outpatient referred to our pain clinic. Methods: Sex, weight, height, cause of orthostatic headache, leakage site evaluation test, epidural blood patch injection level, number of administered epidural blood patches, and pain intensity data were collected. We classified patients into two groups according to the cause of orthostatic headache: spontaneous (Group S) and iatrogenic (Group I). Patients with myelograms were also divided into 2 groups: multiple cerebrospinal fluid (CSF) leakages and no multiple leakages. Results: Overall, 133 patients (162 procedures) were managed using epidural blood patches. Groups S and I included 34 and 99 patients, respectively. In Group I, 90.9% of the patients achieved complete recovery following a single procedure, whereas 44.1% of Group S patients required repeated procedures. The average number of administered epidural blood patches was significantly higher in Group S (1.48 ± 0.64) than in Group I (1.11 ± 0.35; P = 0.007). Among 23 patients evaluated via myelography, 12 had multiple CSF leakages. Patients with multiple leakages required a significantly higher number of epidural blood patches, compared to patients without multiple leakages (P = 0.023). Limitations: This retrospective study reveals several limitations including insufficient evaluation of CSF leakage site by myelogram and the retrospective nature of the study itself. Conclusions: Most patients with iatrogenic orthostatic headache required a single epidural blood patch, although most did not undergo a myelogram or similar test. Patients with spontaneous orthostatic headache or multiple CSF leakages were more likely to require a repeated epidural blood patch. Key words: CSF leakage, dural puncture, epidural blood patch, intracranial hypotension, orthostatic headache, spinal headache
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Aggestam, Lena. "Knowledge Leakage when SMEs Participate in Supply Chains". International Journal of Knowledge and Systems Science 7, n. 3 (luglio 2016): 30–45. http://dx.doi.org/10.4018/ijkss.2016070103.
Testo completoAbstract (sommario):
The advantages of sharing knowledge when participating in a Supply Chain (SC) are well established in the literature, but the challenge of knowledge leakage, and how to manage it, is still in its infancy. In order to increase the understanding of knowledge leakage, when SMEs participate in SCs, this study describes types of knowledge that may leak away, how they are valued, and how knowledge leakage can occur. The result includes two frameworks that also have shown to be potentially useful for examining the maturity of a specific SME with regard to knowledge leakages when participating in the SC.
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Egeli, Tufan, Tarkan Unek, Mucahit Ozbilgin, Mustafa Goztok e Ibrahim Astarcıoglu. "A Novel Technique for Managing Pancreaticojejunal Anastomotic Leak after Pancreaticoduodenectomy". Case Reports in Surgery 2016 (2016): 1–3. http://dx.doi.org/10.1155/2016/5392923.
Testo completoAbstract (sommario):
Pancreaticoduodenectomy (Whipple’s procedure) remains the only definitive treatment option for tumors of the periampullary region. The most common and life-threatening complications following the procedure are pancreatic anastomotic leakage and subsequent fistula formation. When these complications occur, treatment strategy depends on the severity of anastomotic leakage, with patients with severe leakages requiring reoperation. The optimal surgical method used for reoperation is selected from among different options such as wide drainage, definitive demolition of the pancreaticojejunal anastomosis and performing a new one, or completion pancreatectomy. Here we present a novel, simple technique to manage severe pancreatic leakage via ligamentum teres hepatis patch.
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Kleffel, Tobias, Philipp Frey, Marion Merklein e Dietmar Drummer. "Analysis of the formation of gap-based leakages in polymer-metal electronic systems with labyrinth seals". Journal of Polymer Engineering 39, n. 6 (26 luglio 2019): 573–86. http://dx.doi.org/10.1515/polyeng-2019-0098.
Testo completoAbstract (sommario):
Abstract A major challenge in manufacturing polymer-metal electronic systems, for example, encapsulations of metal inserts using assembly injection molding, is to create a tight sealing in order to prevent leakage. One typical reason for leakage is the formation of gaps between polymer and metal. Through labyrinth seals, which can be manufactured by structuring of the metal surface, the gap-based leakage networks can be interrupted. However, in order to use the appropriate structure in the right position, knowledge about the formation of the gaps is essential. The research covered in this paper focuses on the analysis of the formation of gap-based leakages in polymer-metal electronic systems with labyrinth seals to improve the component design of such parts. The effects of different embossed labyrinth seals, which differ in depth and features, and an electrochemically manufactured areal seal on the tightness and leakage position are investigated. Furthermore, the formation of the leakage network is presented for the investigated variants.
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Hu, Zhouhan, Yaxun Wang, Maosheng Ye, Mei Liu e Junqi Ding. "Localization of Potential Leakage Areas inside Plain Reservoirs Using Waterborne Electrical Resistivity Tomography". Journal of Environmental and Engineering Geophysics 26, n. 2 (giugno 2021): 133–43. http://dx.doi.org/10.32389/jeeg20-070.
Testo completoAbstract (sommario):
Leakage of reservoirs will not only lead to the waste of water resources, but also cause soil salinization, dam break, and other serious consequences. Leakages may still occur even anti-seepage engineering measures are taken. This study utilized continuous waterborne electrical resistivity tomography to localize potential bottom geomembrane leakage areas in Datun plain reservoir in the east route of South-to-North Water Diversion project. The integrated sensitivity was firstly evaluated to select the optimum electrode array. Four leakage scenarios were numerically simulated and the resulting resistivity distribution patterns were further categorized to identify leakage locations. A total of 33 field survey lines were measured using floating cables over 5 km2 water surface. Robust inversion method was adopted for delineation of geomembrane interface. In the end, we found most of the soil surfaces are still kept under original flat conditions. Based on the abrupt decrease of resistivity from over 120 Ω·m to 80 Ω·m or lower values, two specific sites under the geomembrane with an area of 0.31 km2 potential leakage areas were localized. Even though there are no clearly leakage signs observed from the reservoir water surface, these resistivity results provide important preliminary data to further narrow down the leakage locations.
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Hendrayana, Heru, Doni Prakasa Eka Putra, Hendy Setiawan, I. Gde Budi Indrawan, Wawan Budianta e Wahyu Wilopo. "Assessment of groundwater leakage source using hydrochemical data and isotopes in the Pandanduri dam tunnel, Lombok Island, Indonesia". Journal of Degraded and Mining Lands Management 10, n. 1 (1 ottobre 2022): 3961. http://dx.doi.org/10.15243/jdmlm.2022.101.3961.
Testo completoAbstract (sommario):
<p>Leakage or seepage in reservoirs and dams has the potential for structural instabilities persuaded by water leakage pathways and linked to economic consequences. An environmental isotopic and hydrochemical research was conducted to determine the source and origin of seepages on the tunnel of Pandanduri dam, Lombok Island, Indonesia. This study aimed to examine the source of the tunnel leak on the dam site and the origin or source of water at the point of leakage based on water chemistry data and stable isotopes. To identify the source of the leakage water in the tunnel dam, 33 samples of the leakage water, groundwater, reservoir water, river water, and rainfall water were taken for chemical and isotopic composition analysis. The field measured the reservoir level, spring discharges, and physicochemical parameters (EC, pH, TDS, TSS). The physicochemical parameters show that the leakages water is similar to reservoir water. The types of leakage water in the tunnel belong to alkaline water, predominantly sulfate-chloride. This type of water is deep groundwater with a higher sulfate and chloride concentration than surface water or shallow groundwater. Hydrochemical and isotope analysis showed that water origin at leakage points is dominated by groundwater.</p>
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Fang, Alex H., Wilson Chao e Melanie Ecker. "Review of Colonic Anastomotic Leakage and Prevention Methods". Journal of Clinical Medicine 9, n. 12 (16 dicembre 2020): 4061. http://dx.doi.org/10.3390/jcm9124061.
Testo completoAbstract (sommario):
Although surgeries involving anastomosis are relatively common, anastomotic leakages are potentially deadly complications of colorectal surgeries due to increased risk of morbidity and mortality. As a result of the potentially fatal effects of anastomotic leakages, a myriad of techniques and treatments have been developed to treat these unfortunate cases. In order to better understand the steps taken to treat this complication, we have created a composite review involving some of the current and best treatments for colonic anastomotic leakage that are available. The aim of this article is to present a background review of colonic anastomotic leakage, as well as current strategies to prevent and treat this condition, for a broader audience, including scientist, engineers, and especially biomedical engineers.
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Costa, V. A. F. "Liquid leakage assessment from gas leakage tests". Measurement 151 (febbraio 2020): 107135. http://dx.doi.org/10.1016/j.measurement.2019.107135.
Testo completo
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Wenger, Frank Axel, Eduard Szucsik, Bogdan Florin Hoinoiu, Anca M. Cimpean, John P. Matonick, Mihai Ionac e Marius Raica. "Is Circular Fibrin Sealing of Low Rectal Anastomosis Able to Prevent Leakage in 21-Day Follow-up? Randomized Experimental Trial in Pigs". Surgical Innovation 26, n. 4 (4 maggio 2019): 408–19. http://dx.doi.org/10.1177/1553350619834786.
Testo completoAbstract (sommario):
Purpose. Clinically apparent anastomotic leakage (AL) after low anterior rectal resection (LAR; <7 cm from anal verge) using circular double-stapled anastomosis without defunctioning stoma is up to 37.5%. However, it is unclear whether there is reduction of LAR after 21 postoperative days without defunctioning stoma but with extraluminal anastomotic application of fibrin sealant. Methods. Forty-eight-week-old pigs underwent LAR and circular double-stapled anastomosis in end-to-end technique (descendo-rectostomy). Animals were randomized into therapy and control group (cg). Therapy group (n = 20) received additional extraluminal circular anastomotic application of fibrin sealant. Objective was to assess incidence of clinically apparent and nonclinically apparent leakage through the 21st postoperative day. Remaining animals were sacrificed on the 21st day, and anastomotic region was analyzed. In case of earlier diagnosed AL, animals were sacrificed. Results. In cg, we observed clinically and nonclinically AL in 20% (n = 4). No animal was identified with a nonclinical-apparent leakage in this group, and all 4 animals with leakages presented clinical signs. In the therapy group, no animal (0/20) developed clinically apparent leakage signs. There were no leakages in this group, but 3 animals had ulcerative lesions without leak and without clinical signs. These lesions were observed intraluminally at crossing of staple lines after 21 days. In one of these animals, incomplete leakage was observed, blocked by fibrin sealant. Conclusion. In circular stapled colorectal anastomosis, circular fibrin glue sealant successfully protected anastomotic intraluminal wall defects at crossing of staple lines, reducing leakage rate from 20% to 0% (cg vs therapy group) after 21 postoperative days.
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Kim, Sung-Hwan, Nam-Uk Kim e Tai-Myoung Chung. "Study on sensitive information leakage vulnerability modeling". Kybernetes 44, n. 1 (12 gennaio 2015): 77–88. http://dx.doi.org/10.1108/k-05-2014-0106.
Testo completoAbstract (sommario):
Purpose – The purpose of this paper is to provide a model for quantitatively analyzing the security profile of an organization’s IT environment. The model considers the security risks associated with stored data, as well as services and devices that can act as channels for data leakages. The authors propose a sensitive information (SI) leakage vulnerability model. Design/methodology/approach – Factors identified as having an impact on the security profile are identified, and scores are assigned based on detailed criteria. These scores are utilized by mathematical models that produce a vulnerability index, which indicates the overall security vulnerability of the organization. In this chapter, the authors verify the model result extracted from SI leakage vulnerability weak index by applying the proposed model to an actual incident that occurred in South Korea in January 2014. Findings – The paper provides vulnerability result and vulnerability index. They are depends on SI state in information systems. Originality/value – The authors identify and define four core variables related to SI leakage: SI, security policy, and leakage channel and value of SI. The authors simplify the SI leakage problem. The authors propose a SI leakage vulnerability model.
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Fleming, J. S., e Y. Tang. "The Analysis of Leakage in a Twin Screw Compressor and its Application to Performance Improvement". Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 209, n. 2 (agosto 1995): 125–36. http://dx.doi.org/10.1243/pime_proc_1995_209_239_02.
Testo completoAbstract (sommario):
The performance of a helical screw compressor is influenced more by the internal gas leakages than by any other thermo-fluid aspect of its behaviour. Six separate types of leakage path can be identified. Only the cusp blow holes have a constant geometry; every other path has a geometry and resistance to flow which varies (periodically) in a manner unique to it. The pressure difference driving the gas along a leakage path also varies (periodically) and does so in a manner that is not the same for every leakage path. This is quite obviously a complex problem requiring insight in modelling the thermo-fluid behaviour and the solution of a large number of simultaneous equations. The distribution of leakage through the various leakage paths within the machine is important for the improvement of the compressor performance. A method of determining the aggregate leakage through each path individually over a complete compression cycle is required to enable this study to be conducted. The authors have constructed a mathematical model of the complete compressor thermofluid process which is suitable for this purpose, its macropredictions having been verified against measured data derived from a test compressor. The nature of its micropredictions and their verification, that is for each leakage path, are the subject of the paper proposed here. Analytical techniques are proposed and experimental methods are discussed. The influence of different rotational speeds on the leakage is considered. Also discussed is the manner in which the leakage distribution prediction could be used to optimize a compressor design.
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Yi, Shuang, e Kosuke Heki. "Heterogeneous oceanic mass distribution in GRACE observations and its leakage effect". Geophysical Journal International 221, n. 1 (10 gennaio 2020): 603–16. http://dx.doi.org/10.1093/gji/ggaa022.
Testo completoAbstract (sommario):
SUMMARY Signal leakage between the land and ocean is a challenge in using Gravity Recovery and Climate Experiment (GRACE) observation data to study global mass redistributions. Although the leakage occurs in both directions, more attention has been paid to the land-to-ocean leakage and less to the ocean-to-land leakage. Here, we show that the ocean-to-land leakage is non-uniform and non-negligible and propose a new forward modelling method to fully consider bi-directional leakages with the help of the global Ocean ReAnalysis System ORAS5. This observation-driven model could significantly reduce the variations in ocean grids and thus decrease the ocean-to-land leakage. The results with different treatment of the ocean signal leakage are compared. We find that failing to consider the ocean-to-land leakage will cause an underestimation of ∼20 per cent in the seasonal variation and will introduce a bias of several giga-tons in the secular trend. Although the uniform and non-uniform model have similar results in the global average of seasonal mass variations, the non-uniform ocean model is necessary in most places, especially near the Arctic Ocean, the Sea of Japan and the Gulf of Carpentaria. Despite these achievements, we also point out that there is still much room for improvement in ocean mass models, particularly in long-term trends. Our results indicate the importance of the ocean-to-land leakage correction in the mass estimation in coastal land areas using the GRACE data.
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Prisca I. Okochi, Stanley A. Okolie e Juliet N. Odii. "An improved data leakage detection system in a cloud computing environment". World Journal of Advanced Research and Reviews 11, n. 2 (30 agosto 2021): 321–28. http://dx.doi.org/10.30574/wjarr.2021.11.2.0385.
Testo completoAbstract (sommario):
An Improved Data Leakage Detection System is designed to mitigate the leakage of crucial and sensitive data in a cloud computing environment. Generally, leakage of data in computing system has caused a lot of irreparable damage or catastrophe to various institutions or organizations worldwide. Therefore, this research aims at detecting and preventing any intentional or non-intentional data leakages using dynamic password or key for data decryption security mechanisms. To achieve this the OOADM methodology was adopted. The new system was implemented using ASP.net MVC and Microsoft SQL Server Management Studio as the backend. And by incorporating an Audit trail/Transaction log mechanism, the new system monitors the activities within and outside the computing environment with date and time stamp. Hence, the system can be applied in any environment for the prevention and detection of any data leakage.
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M, Amreen Ayisha, Dhanalakshmi G, Dhanush Gowda S, Kalyan Kumar R, Keerthana S e Dr Pooja Nayak S. "LPG Leakage Detection in Kitchen Using IOT". International Journal of Engineering Research in Computer Science and Engineering 9, n. 9 (21 settembre 2022): 20–22. http://dx.doi.org/10.36647/ijercse/09.09.art006.
Testo completoAbstract (sommario):
Liquefied Petroleum Gas (LPG) is one of the most used fuels in both domestic and commercial kitchens. Basically, LPG is a combination or mixture of propane and butane which is a highly flammable, colorless chemical and also odorless so an odorant has been added to it to help in detecting the leakage. Gas leakages causes a threat in our households and the surroundings. In recent days, kitchen-based accidents have been increased in both domestic and commercial premises. The main reason for these accidents is gas leakage as it enhances the risk of explosions. To dodge this problem, there is a requirement for an automatic gas leakage detection system to distinguish the spillage of LPG and give alerts. In the present day, IOT (Internet of Things) is extensively used to automate the household appliances. In this paper we are discussing about an Internet of Things (IOT) based system which enables the initial detection of gas leaks which can prevent house fires in a kitchen by measuring the temperature and humidity using sensors. So, if we can detect these gas leakages onset, we can avert a serious explosion and protect lives.
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Kong, Chunyan, Derong Zhang, Rong Cai, Shuangshuang Li e Rongjun Zhu. "Numerical Simulation and Analysis of Diffusion Process for the Leakages of a Tunnel LNG Pipeline". Geofluids 2020 (17 novembre 2020): 1–9. http://dx.doi.org/10.1155/2020/8894047.
Testo completoAbstract (sommario):
Taking a practical project as an example, based on the computational fluid dynamics (CFD), standard k-ε model and finite element method, a mathematical model for the diffusion due to liquefied natural gas (LNG) pipeline leakage in a tunnel was established, and the diffusion process was numerically simulated for three LNG leakage cases. From the simulation results, the variation of CH4 concentration field and explosive gas cloud with time within the tunnel, and the influence of leakage location on the diffusion was analyzed for the three cases. It was shown that the variation of CH4 concentration field had a similar trend for the three cases, but the CH4 explosive gas cloud length increased rapidly with the LNG leakage intensity so that dangerous situations would occur for the medium and large leakages, and a leak location closer to air inlet would lead to a more dangerous situation. When the amount of LNG leakage in the tunnel is large, the effect of mechanical ventilation is obviously weakened. Furthermore, a nitrogen seal precaution was proposed for the situations.
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Fontana, Nicola, Maurizio Giugni e Gustavo Marini. "Experimental assessment of pressure–leakage relationship in a water distribution network". Water Supply 17, n. 3 (11 ottobre 2016): 726–32. http://dx.doi.org/10.2166/ws.2016.171.
Testo completoAbstract (sommario):
The use of numerical simulations to improve the management of water distribution networks (WDNs) has dramatically increased in recent decades. Nevertheless, the modeling of leakages is still a major issue to face when setting up a model of a WDN. Because water losses increase at increasing pressure, they are usually modeled by assuming a leakage node behaves like an emitter. Unfortunately, a definitive assessment of the leakage law exponent is as yet lacking in the literature. Consequently, a field analysis was carried out on an existing WDN: (a) to assess whether the power law can effectively represent the relationship between leakage and pressure; and (b) to calculate the value of the exponent. A 3-month measurement campaign was developed, aiming at assessing the dependence of the losses to the pressure. The analysis showed that the power law equation with an exponent around 0.7 can well represent the pressure–leakage relationship.
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Тихомиров, Виктор, Viktor Tikhomirov, Михаил Измеров e Mikhail Izmerov. "LEAKAGE THROUGH FACE SEAL TAKING INTO ACCOUNT CORRUGATION AND ROUGHNESS". Bulletin of Bryansk state technical university 2016, n. 4 (28 dicembre 2016): 83–93. http://dx.doi.org/10.12737/23169.
Testo completoAbstract (sommario):
The procedure is developed for the assessment of joint impermeability in a metal-metallic split perma-nent connection on the basis of a two-level model of a contact interaction in engineering surfaces where the leakage in sealing environment is defined by a sum of leakages through a joint of corrugated surfaces defined by corrugation parameters and leakage through porous medium formed by a contact of rough surfaces on contour areas of a contact.
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Wagh, K. S. "A Survey: Data Leakage Detection Techniques". International Journal of Electrical and Computer Engineering (IJECE) 8, n. 4 (1 agosto 2018): 2247. http://dx.doi.org/10.11591/ijece.v8i4.pp2247-2253.
Testo completoAbstract (sommario):
Data is an important property of various organizations and it is intellectual property of organization. Every organization includes sensitive data as customer information, financial data, data of patient, personal credit card data and other information based on the kinds of management, institute or industry. For the areas like this, leakage of information is the crucial problem that the organization has to face, that poses high cost if information leakage is done. All the more definitely, information leakage is characterize as the intentional exposure of individual or any sort of information to unapproved outsiders. When the important information is goes to unapproved hands or moves towards unauthorized destination. This will prompts the direct and indirect loss of particular industry in terms of cost and time. The information leakage is outcomes in vulnerability or its modification. So information can be protected by the outsider leakages. To solve this issue there must be an efficient and effective system to avoid and protect authorized information. From not so long many methods have been implemented to solve same type of problems that are analyzed here in this survey. This paper analyzes little latest techniques and proposed novel Sampling algorithm based data leakage detection techniques.