Academic literature on the topic 'Melt leakage'
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Journal articles on the topic "Melt leakage"
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Gonzalez, Mireia Bargallo, Erik Rosseel, Andriy Hikavyy, Tatiana Fernandez-Lanas, Geert Eneman, Peter Verheyen, Roger Loo, Eddy Simoen, and Cor Claeys. "Stress Analysis and Junction Leakage of Sub-Melt Laser Annealed SiGe Epitaxial Layers." IEEE Transactions on Semiconductor Manufacturing 23, no. 4 (November 2010): 538–44. http://dx.doi.org/10.1109/tsm.2010.2050789.
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Hier-Majumder, Saswata, Maxim D. Ballmer, Matthew Agius, Catherine Rychert, and Nicholas Harmon. "Evidence for melt leakage from the Hawaiian plume above the mantle transition zone." Physics of the Earth and Planetary Interiors 321 (December 2021): 106813. http://dx.doi.org/10.1016/j.pepi.2021.106813.
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Marschik, Christian, Wolfgang Roland, Marius Dörner, Georg Steinbichler, and Volker Schöppner. "Leakage-Flow Models for Screw Extruders." Polymers 13, no. 12 (June 9, 2021): 1919. http://dx.doi.org/10.3390/polym13121919.
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Many theoretical analyses of extrusion ignore the effect of the flight clearance when predicting the pumping capability of a screw. This might be reasonable for conventional extruder screws with “normal” clearances but leads to errors when more advanced screw designs are considered. We present new leakage-flow models that allow the effect of the flight clearance to be included in the analysis of melt-conveying zones. Rather than directly correcting the drag and pressure flows, we derived regression models to predict locally the shear-thinning flow through the flight clearance. Using a hybrid modeling approach that includes analytical, numerical, and data-based modeling techniques enabled us to construct fast and accurate regressions for calculating flow rate and dissipation rate in the leakage gap. Using the novel regression models in combination with network theory, the new approximations consider the effect of the flight clearance in the predictions of pumping capability, power consumption and temperature development without modifying the equations for the down-channel flow. Unlike other approaches, our method is not limited to any specific screw designs or processing conditions.
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Kłodowski, Adam, Harri Eskelinen, and Scott Semken. "Leakage-proof nozzle design for RepRap community 3D printer." Robotica 33, no. 4 (March 10, 2014): 721–46. http://dx.doi.org/10.1017/s0263574714000502.
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SUMMARYThe RepRap 3D printer development project is a fast growing, open-hardware initiative relying on the input of hobbyist designers. One of its key components is the printer nozzle. The performance and reliability deficiencies of currently available nozzle designs are common topics in the RepRap community, and our own experience with a RepRap 3D printer has identified a need for improvement in a few particular areas. We set out to eliminate melt leakage, improve thermal isolation, and develop a more effective method of nozzle assembly attachment. Here, we review the issues, describe design efforts, and report results.
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Marschik, Christian, Wolfgang Roland, and Tim A. Osswald. "Melt Conveying in Single-Screw Extruders: Modeling and Simulation." Polymers 14, no. 5 (February 23, 2022): 875. http://dx.doi.org/10.3390/polym14050875.
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Numerous analyses have modeled the flow of polymer melts in the melt-conveying zones of single-screw extruders. While initial studies mainly provided exact analytical results for combined drag and pressure flows of Newtonian fluids, more recently developed, numerical methods seek to deepen the understanding of more realistic flow situations that include shear-thinning and non-isothermal effects. With the advent of more powerful computers, considerable progress has been made in the modeling and simulation of polymer melt flows in single-screw extruders. This work reviews the historical developments from a methodological point of view, including (1) exact analytical, (2) numerical, and (3) approximate methods. Special attention is paid to the mathematical models used in each case, including both governing flow equations and boundary conditions. In addition, the literature on leakage flow and curved-channel systems is revisited.
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Biasotto, Cleber, Viktor Gonda, Lis K. Nanver, Tom L. M. Scholtes, Johan van der Cingel, Daniel Vidal, and Vladimir Jovanović. "Low-Complexity Full-Melt Laser-Anneal Process for Fabrication of Low-Leakage Implanted Ultrashallow Junctions." Journal of Electronic Materials 40, no. 11 (September 9, 2011): 2187–96. http://dx.doi.org/10.1007/s11664-011-1734-6.
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Šadek, Siniša, Srđan Špalj, and Bruno Glaser. "Influence of Modelling Options in RELAP5/SCDAPSIM and MAAP4 Computer Codes on Core Melt Progression and Reactor Pressure Vessel Integrity." Science and Technology of Nuclear Installations 2010 (2010): 1–11. http://dx.doi.org/10.1155/2010/163279.
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RELAP5/SCDAPSIM and MAAP4 are two widely used severe accident computer codes for the integral analysis of the core and the reactor pressure vessel behaviour following the core degradation. The objective of the paper is the comparison of code results obtained by application of different modelling options and the evaluation of influence of thermal hydraulic behaviour of the plant on core damage progression. The analysed transient was postulated station blackout in NPP Krško with a leakage from reactor coolant pump seals. Two groups of calculations were performed where each group had a different break area and, thus, a different leakage rate. Analyses have shown that MAAP4 results were more sensitive to varying thermal hydraulic conditions in the primary system. User-defined parameters had to be carefully selected when the MAAP4 model was developed, in contrast to the RELAP5/SCDAPSIM model where those parameters did not have any significant impact on final results.
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Zainal, Nurfarina, S. J. N. Mitchell, D. W. McNeill, and W. M. Jubadi. "Development of photodiode via the rapid melt growth (RMG) materials for energy conversion device." Indonesian Journal of Electrical Engineering and Computer Science 18, no. 3 (June 1, 2020): 1188. http://dx.doi.org/10.11591/ijeecs.v18.i3.pp1188-1198.
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<span>Germanium (Ge) photodiodes were fabricated with the new RMG crucible materials that were established in this study. Results show that Ge large square patterns with size of 208 µm x 208 µm were unable to be achieved if ion implantation process was used in formation of photodiode. Delamination can be observed on all test samples during polycrystalline silicon (poly-Si) deposition at 620 <sup>o</sup>C. This result was in contrast to a previous intrinsic Ge test structure, where good formation of squares with size similar to that 208 µm x 208 µm had been successfully attained even with high annealing temperature above 938 <sup>o</sup>C. This indicates that doping through ion implantation has affected Ge film and caused delamination even at low temperature. However, good formations of Ge stripes were attained along with the ion implantation process in fabricating the photodiode. Results show that the sheet resistance of Ge stripe has significantly decreased compared to previous Ge resistors. The better resistance is due to the thicker (500 nm) Ge layer. In the case of Ge stripes with a p-i-n junction, only small fraction of test samples have shown a diode characteristic but with high leakage current. Results of I-V measurement show that a large fraction of test samples produced resistor characteristics. The high leakage current is believed due to the fact that the Ge films formed at this stage were polycrystalline in structure. Thus the grain size of Ge stripe has affected the performance. Slight changes on the I-V characteristic of single Ge can be observed when samples were tested under illumination. Therefore, it has potential to be used for future development of energy conversion device. </span>
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Shin, Woo, Suk Ko, Hyung Song, Young Ju, Hye Hwang, and Gi Kang. "Origin of Bypass Diode Fault in c-Si Photovoltaic Modules: Leakage Current under High Surrounding Temperature." Energies 11, no. 9 (September 12, 2018): 2416. http://dx.doi.org/10.3390/en11092416.
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Bypass diodes have been widely utilized in crystalline silicon (c-Si) photovoltaic (PV) modules to maximize the output of a PV module array under partially shaded conditions. A Schottky diode is used as the bypass diode in c-Si PV modules due to its low operating voltage. In this work, we systematically investigated the origin of bypass diode faults in c-Si PV modules operated outdoors. The temperature of the inner junction box where the bypass diode is installed increases as the ambient temperature increases. Its temperature rises to over 70 °C on sunny days in summer. As the temperature of the junction box increases from 25 to 70 °C, the leakage current increases up to 35 times under a reverse voltage of 15 V. As a result of the high leakage current of the bypass diode at high temperature, melt down of the junction barrier between the metal and semiconductor has been observed in damaged diodes collected from abnormally functioning PV modules. Thus, it is believed that the constant leakage current applied to the junction caused the melting of the junction, thereby resulting in a failure of both the bypass diode and the c-Si PV module.
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Mahroug, Imane, Stefania Doppiu, Jean-Luc Dauvergne, Angel Serrano, and Elena Palomo del Barrio. "Li4(OH)3Br-Based Shape Stabilized Composites for High-Temperature TES Applications: Selection of the Most Convenient Supporting Material." Nanomaterials 11, no. 5 (May 13, 2021): 1279. http://dx.doi.org/10.3390/nano11051279.
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Peritectic compound Li4(OH)3Br has been recently proposed as phase change material (PCM) for thermal energy storage (TES) applications at approx. 300 °C Compared to competitor PCM materials (e.g., sodium nitrate), the main assets of this compound are high volumetric latent heat storage capacity (>140 kWh/m3) and very low volume changes (<3%) during peritectic reaction and melting. The objective of the present work was to find proper supporting materials able to shape stabilize Li4(OH)3Br during the formation of the melt and after its complete melting, avoiding any leakage and thus obtaining a composite apparently always in the solid state during the charge and discharge of the TES material. Micro-nanoparticles of MgO, Fe2O3, CuO, SiO2 and Al2O3 have been considered as candidate supporting materials combined with the cold-compression route for shape-stabilized composites preparation. The work carried out allowed for the identification of the most promising composite based on MgO nanoparticles through a deep experimental analysis and characterization, including chemical compatibility tests, anti-leakage performance evaluation, structural and thermodynamic properties analysis and preliminary cycling stability study.
Dissertations / Theses on the topic "Melt leakage"
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Білянін, Роман Володимирович. "Тепловий контроль технічного стану індукційних установок для виробництва мідної катанки." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/41338.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.11.13 – прилади і методи контролю та визначення складу речовин. – Національний технічний університет "Харківський політехнічний інститут", м. Харків, 2019 р.
У дисертації вирішено важливе наукове завдання розвитку методів теплового контролю технічного стану індукційних установок виробництва високоякісної мідної катанки на основі використання математичного моделювання електротеплових процесів, аналізу розподілу температури в багатошаровій термоізоляції установок з урахуванням її деградації та розподілу температури на їх поверхні, що має суттєве значення для розвитку кабельної промисловості. Розроблено новий метод неруйнівного контролю технічного стану індукційних установок для виготовлення мідної катанки енергетичного призначення, в якому крім вимірювання реактивного та активного опорів індуктора та різниці температури води у системі охолодження додатково визначається ступінь деградації багато-шарової термоізоляції шляхом порівняння розрахункового розподілу поточної температури в об'ємі розплаву та ізоляції на тривимірній математичній моделі установки з практичним вимірюванням температури локальних областей (у роботі їх було 72) поверхні корпусу печі. Це дає можливість точніше прогнозувати ресурс печі та завчасно виявляти режими її роботи близькі до аварійних. Розроблено нове технічне рішення з удосконалення багатошарової термоізоляції індукційних установок з метою зменшення їхніх енерговитрат і збільшення ресурсу. Воно полягає у застосуванні замість третього термоізоляційного шару з легковагої цегли трьох шарів: монолітного вогнетривкого бетону, легковагої цегли та вогнетривкого паперу, зі збереженням загальної товщини ізоляції. Впровадження результатів дисертації в індукційній установці UPCAST US20X-10 для виготовлення мідної катанки в ПАТ "ЗАВОД ПІВДЕНКАБЕЛЬ" дало позитивні результати у зниженні на 20°C температури на корпусі печі, скороченні на 5-15% питомої витрати електроенергії на 1 тонну катанки та поліпшенні її якості шляхом зменшення відсотку сторонніх домішок і забезпечення вмісту в ній міді 99,99%.The thesis for a Candidate of Engineering Sciences degree by specialty 05.11.13 – devices and methods of control and determination of composition of substances. – National technical university "Kharkov polytechnic institute", Kharkiv, 2019. The thesis solves the important scientific task to improve methods of control of the technical condition of induction installations for the production of high-quality copper rod using the mathematical modeling of electrothermal processes in copper melt and multi-layer thermal insulation, with taking into account its degradation and temperature distribution on the installation surface, which is essential for the development of cable industry. A new method of non-destructive control of the technical condition of induction installations for the production of copper rod for power cables of energy value is developed, in which in addition to measuring the reactive and active resistances of the inductor and the reduction of the water temperature in the cooling system, the degree of degradation of multilayer thermal insulation is additionally determined by comparing the calculated distribution of the current temperature in the volume of melt and insulation on a three-dimensional mathematical model of the installation with practical measurement of temperature in local areas (in the work they were 72) of the surface of the furnace casing. This makes it possible to more accurately predict the furnace's profile and to detect the modes of its operation in a timely manner close to the emergency. A new technical solution for improving the multilayer thermoinsulation of induction installations has been developed in order to reduce their energy consumption and increase the resource. It consists in applying instead of the third thermal insulation layer of light-weight brick of three layers: monolithic refractory concrete, lightweight brick and refractory paper, with the preservation of the overall thickness of the insulation. The implementa-tion of the developed lining structure improvement at PJSC " YUZHCABLE WORKS" in the UPCAST US20X-10 induction installation for copper rod in the cable industry in Ukraine has yielded positive results in a 20°C decrease in the temperature of the furnace casing, a reduction of 5-15% of the specific cost Electricity for 1 ton of production and improvement of quality of copper rod, by reducing the percentage of foreign impurities and ensuring copper content in it 99,99%.
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Білянін, Роман Володимирович. "Тепловий контроль технічного стану індукційних установок для виробництва мідної катанки." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2019. http://repository.kpi.kharkov.ua/handle/KhPI-Press/41340.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.11.13 – прилади і методи контролю та визначення складу речовин. – Національний технічний університет "Харківський політехнічний інститут", м. Харків, 2019 р.
У дисертації вирішено важливе наукове завдання розвитку методів теплового контролю технічного стану індукційних установок виробництва високоякісної мідної катанки на основі використання математичного моделювання електротеплових процесів, аналізу розподілу температури в багатошаровій термоізоляції установок з урахуванням її деградації та розподілу температури на їх поверхні, що має суттєве значення для розвитку кабельної промисловості. Розроблено новий метод неруйнівного контролю технічного стану індукційних установок для виготовлення мідної катанки енергетичного призначення, в якому крім вимірювання реактивного та активного опорів індуктора та різниці температури води у системі охолодження додатково визначається ступінь деградації багато-шарової термоізоляції шляхом порівняння розрахункового розподілу поточної температури в об'ємі розплаву та ізоляції на тривимірній математичній моделі установки з практичним вимірюванням температури локальних областей (у роботі їх було 72) поверхні корпусу печі. Це дає можливість точніше прогнозувати ресурс печі та завчасно виявляти режими її роботи близькі до аварійних. Розроблено нове технічне рішення з удосконалення багатошарової термоізоляції індукційних установок з метою зменшення їхніх енерговитрат і збільшення ресурсу. Воно полягає у застосуванні замість третього термоізоляційного шару з легковагої цегли трьох шарів: монолітного вогнетривкого бетону, легковагої цегли та вогнетривкого паперу, зі збереженням загальної товщини ізоляції. Впровадження результатів дисертації в індукційній установці UPCAST US20X-10 для виготовлення мідної катанки в ПАТ "ЗАВОД ПІВДЕНКАБЕЛЬ" дало позитивні результати у зниженні на 20°C температури на корпусі печі, скороченні на 5-15% питомої витрати електроенергії на 1 тонну катанки та поліпшенні її якості шляхом зменшення відсотку сторонніх домішок і забезпечення вмісту в ній міді 99,99%.The thesis for a Candidate of Engineering Sciences degree by specialty 05.11.13 – devices and methods of control and determination of composition of substances. – National technical university "Kharkov polytechnic institute", Kharkiv, 2019. The thesis solves the important scientific task to improve methods of control of the technical condition of induction installations for the production of high-quality copper rod using the mathematical modeling of electrothermal processes in copper melt and multi-layer thermal insulation, with taking into account its degradation and temperature distribution on the installation surface, which is essential for the development of cable industry. A new method of non-destructive control of the technical condition of induction installations for the production of copper rod for power cables of energy value is developed, in which in addition to measuring the reactive and active resistances of the inductor and the reduction of the water temperature in the cooling system, the degree of degradation of multilayer thermal insulation is additionally determined by comparing the calculated distribution of the current temperature in the volume of melt and insulation on a three-dimensional mathematical model of the installation with practical measurement of temperature in local areas (in the work they were 72) of the surface of the furnace casing. This makes it possible to more accurately predict the furnace's profile and to detect the modes of its operation in a timely manner close to the emergency. A new technical solution for improving the multilayer thermoinsulation of induction installations has been developed in order to reduce their energy consumption and increase the resource. It consists in applying instead of the third thermal insulation layer of light-weight brick of three layers: monolithic refractory concrete, lightweight brick and refractory paper, with the preservation of the overall thickness of the insulation. The implementa-tion of the developed lining structure improvement at PJSC " YUZHCABLE WORKS" in the UPCAST US20X-10 induction installation for copper rod in the cable industry in Ukraine has yielded positive results in a 20°C decrease in the temperature of the furnace casing, a reduction of 5-15% of the specific cost Electricity for 1 ton of production and improvement of quality of copper rod, by reducing the percentage of foreign impurities and ensuring copper content in it 99,99%.
Book chapters on the topic "Melt leakage"
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Herrmann, Nico, Harald S. Müller, Sylvie Michel-Ponnelle, Benoît Masson, and Myriam Herve. "The PACE-1450 Experiment – Investigations Regarding Crack and Leakage Behaviour of a Pre-stressed Concrete Containment." In High Tech Concrete: Where Technology and Engineering Meet, 1487–95. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-59471-2_171.
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Kamei, Keita, Tae-Ho Ahn, Jun-Hui Park, Tatsuro Hashimoto, Norihiko Ogura, and Toshiharu Kishi. "Investigation of New Repair Countermeasure Methods Using Crack Self-healing Technologies for Water Leakage Prevention on Subway Tunnels." In High Tech Concrete: Where Technology and Engineering Meet, 242–49. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-59471-2_30.
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Yang, Yunpeng, Jianchun Fan, Di Liu, and Fanfan Ma. "Monitoring and Diagnosis System of Downhole Tubing Leakage." In Frontiers in Artificial Intelligence and Applications. IOS Press, 2021. http://dx.doi.org/10.3233/faia210300.
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The downhole tubing in a gas well is affected by many factors such as high pressure erosion, gas lift operation, sand production at the bottom of the well and engineering construction, etc., which can easily lead to leakage of the threaded joints of the tubing and the pipe body, and the leaked natural gas will invade Annulus, making the annulus under pressure. The annular pressure caused by oil pipe leakage is a major safety hazard in oil and gas production. Therefore, the accurate diagnosis the degree of leakage of downhole tubing is of great significance to preventing the occurrence of production accidents effectively. To this end, a set of downhole tubing leak monitoring and diagnosis system has been developed by integrating fluid monitoring, acoustic wave detection and tracer detection technology, and the developed tubing leak monitoring and diagnosis system was used for leak detection tests on offshore platforms. The test results show that the developed tubing leakage monitoring and diagnosis system can meet the need of offshore gas well diagnosis, and realize the holographic diagnosis of the leakage degree of the downhole tubing without moving the downhole tubing string.
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Boroomandnia, Arezoo, Omid Bozorg-Haddad, Jimmy Yu, and Mariam Darestani. "Nanotechnology application in water resource management." In Water Resources: Future Perspectives, Challenges, Concepts and Necessities, 33–62. IWA Publishing, 2021. http://dx.doi.org/10.2166/9781789062144_0033.
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Abstract Fast-growing water demand, population growth, global climate change, and water quality deterioration all drive scientists to apply novel approaches to water resource management. Nanotechnology is one of the state-of-the-art tools in scientists’ hands which they can use to meet human water needs via reuse of water and utilizing unconventional water resources. Additionally, monitoring water supply systems using new nanomaterials provides more efficient water distribution networks. In this chapter, we consider the generic concepts of nanotechnology and its effects on water resources management strategies. A wide range of nanomaterials and nanotechnologies, including nano-adsorbents, nano-photocatalysts, and nano-membranes, are introduced to explain the role of nanotechnology in providing new water resources to meet growing demand. Also, nanomaterial application as a water alternative in industry, reducing water demand in the industrial sector, is presented. Another revolution made by nanomaterials, also discussed in this chapter, is their use in water supply systems for monitoring probable leakage and leakage reduction. Finally, we present case studies that clarify the influence of nanotechnology on water resources and their management strategies. These case studies prove the importance and inevitable application of nanotechnology to satisfy the rising water demand in the modern world, and show the necessity of nanotechnology awareness for today's water experts.
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Zhao, S., and H. Huang. "Deep learning-based instance segmentation for water leakage defects of Metro Shield Tunnel." In Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 3475–82. CRC Press, 2019. http://dx.doi.org/10.1201/9780429424441-368.
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Zhao, S., and H. Huang. "Deep learning-based instance segmentation for water leakage defects of Metro Shield Tunnel." In Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 3475–82. CRC Press, 2020. http://dx.doi.org/10.1201/9781003031635-98.
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Zhao, S., and H. Huang. "Deep learning-based instance segmentation for water leakage defects of Metro Shield Tunnel." In Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 3475–82. CRC Press, 2020. http://dx.doi.org/10.4324/9781003031635-98.
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Konishi, S., N. Imaizumi, Y. Enokidani, J. Nagaya, Y. Machijima, S. Akutagawa, and K. Murakoshi. "Effective water leakage detection by using an innovative optic fiber sensing for aged concrete lining of urban metro lines in Tokyo." In Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2383–92. CRC Press, 2019. http://dx.doi.org/10.1201/9780429424441-252.
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Xu, Hui, Lulu Fang, Qiaofeng Ding, Yanjun Guo, Xiaohui Li, Lu Wang, and Lin Yang. "Investigation on the Micromechanisms of the Cracking of 316L Heat Exchanger Tubes." In Advances in Transdisciplinary Engineering. IOS Press, 2021. http://dx.doi.org/10.3233/atde210283.
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The cracking mechanisms of 316L heat exchanger tubes employed in power station were studied using optical microscope (OM) and scanning electron microscope (SEM). It is demonstrated that the hardness value, microstructure and tensile properties of selected #1 and #2 tube samples all meet the requirements of relevant standards, but the contents of Ni and Mo element of #1 tube are slightly lower than the standard requirements. The circumferential cracks on the two samples nucleate at the corrosion pits on the inner wall of the tubes, while Cl element was detected in the corrosion products of these pits. The cracks propagate from the inner wall to the outer wall along the circumferential direction of the tube, forming a dendritic crack morphology with both transgranular and intergranular propagation characteristics. Combined with the investigation of the service condition of the heat exchanger tubes and the analysis of the experimental results, it can be concluded that the main reason for cracking is the initiation of pin-corrosion when the content of chloride ion exceeds the standard during the service of the tubes, which will induce stress corrosion cracking, causing crack expansion through the wall thickness, and finally lead to leakage of the tube. In addition, from the point of view of materials, Mo is an important element to improve the pitting resistance of materials. The content of Mo element detected in the samples is lower than the standard requirement, which is also one of the reasons for the easy pitting corrosion of the inner wall of the pipe.
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Setyawati, Titik, Ricky Aditya, and Tinni Trihartini Maskoen. "Sepsis Associated Acute Kidney Injury." In Infectious Diseases and Sepsis [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97609.
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AKI is a syndrome consisting of several clinical conditions, due to sudden kidney dysfunction. Sepsis and septic shock are the causes of AKI and are known as Sepsis-Associated AKI (SA-AKI) and accounted for more than 50% of cases of AKI in the ICU, with poor prognosis. Acute Kidney Injury (AKI) is characterized by a sudden decline in kidney function for several hours/day, which results in the accumulation of creatinine, urea and other waste products. The most recent definition was formulated in the Kidney Disease consensus: Improving Global Outcome (KDIGO), published in 2012, where the AKI was established if the patient’s current clinical manifestation met several criteria: an increase in serum creatinine levels ≥0.3 mg/dL (26.5 μmol/L) within 48 hours, an increase in serum creatinine for at least 1.5 times the baseline value within the previous 7 days; or urine volume ≤ 0.5 ml/kg body weight for 6 hours. The AKI pathophysiology includes ischemic vasodilation, endothelial leakage, necrosis in nephrons and microtrombus in capillaries. The management of sepsis associated with AKI consisted of fluid therapy, vasopressors, antibiotics and nephrotoxic substances, Renal Replacement Therapy (RRT) and diuretics. In the analysis of the BEST Kidney trial subgroup, the likelihood of hospital death was 50% higher in AKI sepsis compared to non-sepsis AKI. Understanding of sepsis and endotoxins that can cause SA-AKI is not yet fully known. Some evidence suggests that renal microcirculation hypoperfusion, lack of energy for cells, mitochondrial dysfunction, endothelial injury and cycle cell arrest can cause SA-AKI. Rapid identification of SA-AKI events, antibiotics and appropriate fluid therapy are crucial in the management of SA-AKI.
Conference papers on the topic "Melt leakage"
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Rahman, M. Shafiqur, Jonathan Ciaccio, and Uttam K. Chakravarty. "A Machine Learning Approach for Predicting Melt-Pool Dynamics of Ti-6Al-4V Alloy in the Laser Powder-Bed Fusion Process." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-71348.
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Abstract This paper presents a supervised machine learning (ML) model to predict the melt-pool geometries of Ti-6Al-4V alloy in the laser powder-bed fusion (L-PBF) process. The ML model is developed based on the normalized values of the five key features (i.e., the laser and material parameters) — laser power, scanning speed, spot size, powder layer thickness, and powder porosity. The two target variables are the melt-pool width and depth, which define the melt-pool geometry and strongly correlate the geometry with the melt-pool dynamics. Information about the features and the corresponding target variables are compiled from an extensive literature survey. A trained data set is created with the melt-pool evolution data collected from experiments. The data set is divided into training and testing sets before any feature engineering, visualization, and analysis, to prevent any data leakage. The k-fold cross-validation technique is applied to minimize the error and find the best performance. Multiple regression methods are trained and tested to find the best model to predict the melt-pool geometry data. Extra trees regressor is found to be the model with the least amount of error using the mean absolute error function. The verification of the ML model is performed by comparing its results with the experimental and CFD modeling results for the melt-pool geometry at a given combination of the processing parameters in the L-PBF process. The melt-pool geometry outputs obtained for the ML model are consistent with the experimental and CFD modeling results.
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Gao, Yongjian, Yinbiao He, Ming Cao, Yuebing Li, Shiyi Bao, and Zengliang Gao. "Structural Integrity Research for Reactor Pressure Vessel Under In-Vessel Retention of a Core Melt." In 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60092.
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In-Vessel Retention (IVR) is one of the most important severe accident mitigation strategies of the third generation passive Nuclear Power Plants (NPP). It is intended to demonstrate that in the case of a core melt, the structural integrity of the Reactor Pressure Vessel (RPV) is assured such that there is no leakage of radioactive debris from the RPV. This paper studied the IVR issue using Finite Element Analyses (FEA). Firstly, the tension and creep testing for the SA-508 Gr.3 Cl.1 material in the temperature range of 25°C to 1000°C were performed. Secondly, a FEA model of the RPV lower head was built. Based on the assumption of ideally elastic-plastic material properties derived from the tension testing data, limit analyses were performed under both the thermal and the thermal plus pressure loading conditions where the load bearing capacity was investigated by tracking the propagation of plastic region as a function of pressure increment. Finally, the ideal elastic-plastic material properties incorporating the creep effect are developed from the 100hr isochronous stress-strain curves, limit analyses are carried out as the second step above. The allowable pressures at 0 hr and 100 hr are obtained. This research provides an alternative approach for the structural integrity evaluation for RPV under IVR condition.
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Li, Gen, Shan Zheng, Akifumi Yamaji, Daotong Chong, and Junjie Yan. "Investigation on Accident Progression and Melt Behavior at the Fukushima Daiichi Units 1 and 2 Using MELCOR Code." In 2017 25th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/icone25-66389.
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The accident progression and melt behavior at the Fukushima Daiichi Units 1 and 2 were investigated using MELCOR 2.1. In the modeling the lower head failure mechanism by penetration tube rupture and ejection was modeled. In the modeling of Unit 2, according to the latest findings by TEPCO investigation, the possibilities of torus room flooding, RCIC piping leakage and thermal stratification in suppression pool were taken into account. The analysis results indicate that for Unit 1 when considering penetration tube failure, a part of debris still remained in the lower head after debris discharge; otherwise all the debris discharged out. The present MELCOR modeling of Unit 2 well reproduced the RPV and PCV pressure. A part of the core was damaged and the debris that slumped into the lower head was sufficiently cooled down. The pressure vessel kept intact.
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Chen, Yaodong, Yongzhong Wu, and Hui Zhang. "Lingao II Source Term Analysis of a Mitigated Severe Accident Scenario." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48044.
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A typical scenario, Station-Black-Out, which makes up an important part of contribution to core degradation frequency of three loop PWR Lingao phase II according to the PSA level 1 studies, was selected in this paper for Severe Accident Analysis with the application of combination of MELCOR and COCOSYS. Of the scenario, concurrent with postulated power recovery before degradation proceeded to failure of lower head, the evolution of in_vessel phase was studied; a detailed phenomena covering heat-up and dry-out of primary system, collapse and melt down of fuel assemblies, thermal hydraulic response inside the containment compartments, release and accumulation of H2 and fission product (FP) source terms, their leakage into environment were simulated and investigated. The effectiveness of preventive and mitigative measures, such as dedicated core depressurization system (DCDS), passive autocatalytic recombiner (PAR) system, are somehow validated through the calculation; the results also indicated that with the power recovered at 6 hour to start up ECCS, the corium could be retained above support plate.
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Chi, Pun Meng, Chew Gim Eng, and Nazita Sulaiman. "Packaging Material has Contributed to High Idd_Pd Failures in CMOS ICs." In ISTFA 2006. ASM International, 2006. http://dx.doi.org/10.31399/asm.cp.istfa2006p0118.
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Abstract An aggressive yield improvement program that was undertaken by the engineering teams has culminated in the works reported in this paper. The power down current (Idd_Pd) was one of the major failure modes recorded for CMOS ICs. In essence, any improvement made on the Idd_Pd test yield will result in substantial gain in terms of cost and production capacity. A taskforce to resolve high fallouts for the Idd_Pd was then formed back in the year 2004. This taskforce comprised of members from various engineering teams, for instance, Manufacturing, IC Design, Materials and Failure Analysis (FA). The length of investigation to resolve the complex high Idd_Pd failures had spanned over a period of a year. The team had devised a comprehensive sets of DOEs (Design of Experiments) which were conducted at various contract manufacturing facilities where the ICs were packaged. Results obtained from these DOEs had conclusively pointed to molded materials as the major factor contributing to high Idd_Pd yield loss. Armed with this vital information, FA had performed an indepth electrical diagnosis as well as physical analysis on the molded materials. The analysis results had confirmed contamination of the molding materials by conductive carbonized resin as the cause of high leakage current in ICs. Likewise, the material supplier had found minute contamination in the resin melt. In essence, Idd_Pds that were measured in the range of tens of microamps to thousands of microamps in ICs could be largely attributed to leakages caused by carbonized resin in the molded materials.
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Wang, Wung Jae, and Man Sung Yim. "CFD Analysis and Structural Safety Assessment of a Bypass Mitigation Device Used During a Ti-SGTR Accidental Release From a MSSV." In ASME 2019 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/pvp2019-93511.
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Abstract In Nuclear power plants, Main steam safety valve (MSSV) is a barrier to prevent overpressure of steam flow by opening the secondary cycle to the atmosphere. Since MSSVs operate at condition of high temperature and pressure, they have possibility for stuck-open failure. If this accident occurs, large amount of steam or gases release through failed MSSV. It may lead Thermally-induced Steam generator tube rupture (TI-SGTR) due to sudden high gradient of temperature and pressure. With loss of electrical power, TI-SGTR occurs, Core will start to melt in 2–3hours after loss of electrical power. When TI-SGTR occurs with core melt, Leakage of radioactive material occurs through MSSV to environment. Though the probability of an accident is very low, the release of radioactive material can lead large cancer risk to the public. Therefore, many studies to mitigate the radioactive materials are in progress such as diversion to containment building or capturing with external mitigation system. In this study, we are focusing on this capturing device. The objective of this study is to analyze integrity of mitigation device using fluid behavior from MSSV to capturing pipe. Hydraulic conditions at safety valve inlet were used from previous researches. Using commercial simulation software, computational fluid dynamics (CFD) analysis was performed for distribution of fluid temperature, pressure, velocity in MSSV and pipes. For structural safety assessment, 1-way Fluid-Structure interaction (FSI) method was used. CFD result was applied for load on structure surfaces to simulate transient structural analysis of mitigation device. As a result, stresses, strains of capturing pipe were calculated and integrity was discussed.
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Naitoh, Masanori, Marco Pellegrini, Hiroaki Suzuki, Hideo Mizouchi, and Hidetoshi Okada. "Analysis of Accident Progression of Fukushima Daiichi NPP by the SAMPSON Code." In 2014 22nd International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/icone22-30607.
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This paper describes analysis results of the early phase accident progression of the Fukushima Daiichi Nuclear Power Plant (NPP) Unit 1 by the severe accident analysis code SAMPSON. The isolation condensers were the only devices for decay heat removal at Unit 1, but they stopped after the loss of AC and DC powers. Since there were no decay heat removal for about 14 hours after their termination until the start of alternative water injection into the core by the fire engine, the core melt and the reactor pressure vessel (RPV) bottom failure occurred resulting in large amount of fission products release into the environment. The original SAMPSON was improved by adding new modellings for the phenomena which have been deemed specific to the Fukushima Daiichi NPP: (1) deterioration of SRV gaskets and (2) buckling of in-core-monitor housings which caused the early steam leakage from the core into the drywell, and (3) melt of the in-core-monitor housings in the lower plenum of the RPV. The analysis results showed that (1) 55.3% of UO2 of the initial loading and 66.1% of the core material including UO2, zircaloy, steel and control materials had melted down into the pedestal of the drywell, (2) the amount of Hydrogen generated by Zr-H2O reaction was 686 kg, (3) amount of Cs element released from fuels was 61 kg which was 72% of the total Cs element which was included in fuels at the initiation of the accident, and (4) 18.3% of the corium which fell into the pedestal was one large lump and the 81.7% was particulate corium.
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Aliheidari, Nahal, Cameron Hohimer, and Amir Ameli. "3D-Printed Conductive Nanocomposites for Liquid Sensing Applications." In ASME 2017 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/smasis2017-3855.
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Additive manufacturing (AM) offers a new and unique method for the fabrication of functional and smart material and structures. In this method, parts are fabricated directly from a 3D computer model layer by layer. Fused deposition modeling (FDM) is the most widely adapted AM method. In this method, the feedstock is usually a thermoplastic-based material. In recent years, flexible smart materials have gained unflagging interests due to their promising applications in health monitoring, sensing, actuation, etc. However, the 3D printing of flexible materials is recent with its own challenges and limited sources of feedstock. Conductive polymer nanocomposites (CPNs) have many promising uses within sensing filed including liquid sensing. Sensing chemical leakage is one the important capabilities of liquid sensors. There is a good number of studies on the fabrication and sensitivity characterization of CPN-based liquid sensors. However, the sensitivity and response time of CPN-based liquid sensors do not yet meet the industrial demands and should be further enhanced for their practical and widespread applications. This study presents an attempt to integrate the tunability of CPN’s conductivity behavior and the design flexibility of 3D printing to explore the benefits that their coupling may offer toward more sensitive and/or faster liquid sensing. Thermoplastic polyurethane/multiwalled carbon nanotube (TPU/MWCNT) nanocomposites were selected as a model material system and their filaments were first fabricated using melt-mixing by twin-screw extruder at 1, 2 and 3 wt.% of MWCNT. Flexible U-shaped TPU/MWCNT specimens were designed and successfully 3D-printed as a liquid sensor. Specimens fabricated at three different raster patterns of linear, 0–90, and 45/−45 and three infill percent levels of 100, 75, and 50%. Ethanol was used as the model chemical and the resistivity change of the sensors was measured as a function of time when immersed in ethanol. The results revealed that the printed sensors greatly outperformed the pressed bulk counterparts. This enhancement in the 3D printed sensors was primarily due to the increased surface area, and thus higher surface/volume ratio, enabling faster liquid uptake. In addition, MWCNT content, raster pattern, and infill percent all affected the overall response time as well as the sensor sensitivity. This work suggests that highly sensitive liquid sensors can be developed by material and structure optimizations via FDM 3D printing.
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Sugimoto, Jun. "Important Severe Accident Research Issues After Accident at Fukushima Daiichi Nuclear Power Station." In 2013 21st International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icone21-16796.
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After the accident at Fukushima Daiichi Nuclear Power Station several investigation committees issued reports with lessons learned from the accident in Japan. Among those lessons, some recommendations have been made on severe accident research. Similar to the EURSAFE efforts under EU Program, review of specific severe accident research items was started before Fukushima accident in working group of Atomic Energy Society of Japan (AESJ) in terms of significance of consequences, uncertainties of phenomena and maturity of assessment methodology. Re-investigation has been started after the Fukushima accident in this working group. Additional effects of Fukushima accident, such as core degradation behaviors, sea water injection, containment failure/leakage and re-criticality have been covered. The review results are categorized in ten major fields; core degradation behavior, core melt coolability/retention in containment vessel, function of containment vessel, source term, hydrogen behavior, fuel-coolant interaction, molten core concrete interaction, direct containment heating, recriticality and instrumentation in severe accident conditions. In January 2012, Research Expert Committee on Evaluation of Severe Accident was established in AESJ in order to investigate severe accident related issues for future LWR development and to propose action plans for future severe accident research, in collaboration with this working group. Based on these activities and also author’s personal view, the present paper describes the perspective of important severe accident research issues after Fukushima accident. Specifically those are investigation of damaged core and components, advanced severe accident analysis capabilities and associated experimental investigations, development of reliable passive cooling system for core/containment, analysis of hydrogen behavior and investigation of hydrogen measures, enhancement of removal function of radioactive materials of containment venting, advanced instrumentation for the diagnosis of severe accident and assessment of advanced containment design which excludes long-term evacuation in any severe accident situations.
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Li, Ran, and Jiyang Yu. "Development of PCCSAP-3D Code for Passive Containment: Models of Noncondensable Gases, Aerosols and Fission Products." In 2013 21st International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icone21-15606.
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PCCSAC-3D is a code originally developed for AC600 containment thermo-hydraulic analysis. Its validated capabilities include simulating the behaviors of steam-air mixture and liquid water under the unique conditions of an AC600/AP1000 containment after a DBA. The film-tracking model applied gives it the ability to simulate the liquid film both outside and inside the steel containment. Refined with some new models, the new version of the code, named PCCSAP-3D, can cover hydrogen behavior, fission products behavior (in the form of gas and aerosol) and iodine behavior. In the module of noncondensable gas, diffusion of up to 11 species are taken into consideration. A user-definable recombiner/ignitor model is developed to accommodate different types of hydrogen recombiners and ignitors. Given the source term as a boundary condition, the fission products model would be able to track up to 64 radio-isotopes after a LOCA. The leakage and spontaneous decay is accounted for all of these nuclides. Besides, the noble gases, gaseous iodine and fission product aerosols are treated separately. There is no removal mechanism of noble gases. Whereas removal mechanisms of radio-aerosols considered include spray, gravitational sedimentation, diffusio-phoresis and thermo-phoresis. A simple model for gaseous iodine comprises organic iodine and elemental iodine, in which the effects of spray and liquid adsorption are treated integrally. To evaluate the radioactivity consequences of a certain accident, a radioactivity calculation model is brought out to convert the molar concentration or mass concentration of radioactive material into radioactivity concentration. The new version of PCCSAP-3D code with models aforementioned is preliminarily validated by comparing the simulation results with safety analysis results reported in AP1000 Design Control Document. The accident scenario is set as a design basic LOCA with core melt.